FLUORIDE ACTION NETWORK PESTICIDE PROJECT

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2004 Fluoride Abstracts. Part 2.

Abstracts for the following years:
Part 1 - mainly biochemistry and physiology (brain, hormonal, G-proteins, etc.)
Part 2 ("b") - all other

2007

2007-b

2004

2004-b

2001

2001-b

1998

1998-b

1995

1995-b

1992

1992-b

1989

1989-b

1986

1986-b

1983

1982

1976 -
1977
1970 -
1971

2006

2006-b

2003

2003-b

2000

2000-b

1997

1997-b

1994

1994-b

1991

1991-b

1988

1988-b

1985

1985-b

1981

1980

1974 -
1975
1968 -
1969

2005

2005-b

2005-b continued

2002

2002-b

1999

1999-b

1996

1996-b

1993

1993-b

1990

1990 -b

1987

1987-b

1984

1984-b

1979

1978

1972 -
1973
Up to
1967


October 2004.

USDA National Fluoride Database of Selected Beverages and Foods.

Prepared by
• Nutrient Data Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, U.S. Department of Agriculture,
in collaboration with
• University of Minnesota, Nutrition Coordinating Center (NCC);
• University of Iowa, College of Dentistry;
• Virginia Polytechnic Institute and State University, Food Analysis, Laboratory Control Center;
• National Agricultural Statistics Service (NASS), CSREES, USDA; and
• Food Composition Laboratory (FCL), Beltsville Human Nutrition Research Center, Agricultural Research Service, U.S. Department of Agriculture.

Introduction - Assessment of fluoride intake is paramount in understanding the mechanisms of fluoride metabolism specifically the prevention of dental caries, dental fluorosis, and skeletal fluorosis. The Institute of Medicine (IOM, 1997) specified Adequate Intakes (AI) of 0.01 mg/day for infants through 6 months, 0.05 mg/kg/day beyond 6 months of age, and 3 mg/day and 4 mg/day for adult women and men (respectively), to prevent dental caries. Upper limits (UL) of 0.10 mg/kg/day in children less than 8 years and 10 mg/day for those older than 8 years are recommended for prevention of dental fluorosis. Similar levels have been endorsed by the American Dental Association (ADA, 1994) and the American Dietetic Association (ADA, 2000). Fluoride works primarily via topical mechanisms to inhibit demineralization, to enhance remineralization, and to inhibit bacteria associated with tooth decay (Featherstone, 2000). Fluoride has an affinity for calcified tissues. Studies of exposure and bone mineral density, fractures and osteoporosis would benefit from a national fluoride database coupled with an intake assessment tool (Phipps, 1995; Phipps et al., 2000). Therefore, a database for fluoride is needed for epidemiologists and health researchers to estimate the intakes and to investigate the relationships between intakes and human health.

The Nutrient Data Laboratory (NDL), Agriculture Research Service, US Department of Agriculture (USDA) coordinated the development of this USDA National Fluoride Database of Selected Beverages and Foods subsequently described as the National Fluoride Database--a critical element of the comprehensive multi-center National Fluoride Database and Intake Study (NFDIAS). The National Fluoride Database will be incorporated into a computer-based fluoride assessment tool being developed by the University of Minnesota, Nutrition Coordinating Center (NCC), as a module of the Nutrition Data System for Research (NDS-R) software.

The National Fluoride Database is a comprehensive, nationally representative database of the fluoride concentration in foods and beverages consumed in the United States. It contains fluoride values for beverages, water, and foods that are major fluoride contributors. Water and water-based beverages are the chief source of dietary fluoride intake (Singer and Ophaug, 1984). Conventional estimates are that about 75% of dietary fluoride comes from water and water-based beverages. According to the 1992 Fluoridation Census (CDC, 1993), about 63% of the population on U.S. public water systems are receiving water that is fluoridated naturally or by adding fluoride. Drinking water fluoride distributions may vary widely over geographical and geo-political boundaries (CDC, 1993). Variations occur with soil composition and with local political decisions to fluoridate water. The use of wells of varying depths, commercial water products, home water purifiers, and filtration systems also increase variability of fluoride in drinking water and complicate estimates of intake (Brown and Aaron, 1991; Robinson et al.1991; Van Winkle et al., 1995). These variations in fluoride in commercial foods and beverages have been addressed in this National Fluoride Database.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15316185

Caries Res. 2004 Sep-Oct;38(5):421-9.
 
A Probabilistic Estimation of Fluoride Intake by Infants up to the Age of 4 Months from Infant Formula Reconstituted with Tap Water in the Fluoridated Regions of Ireland.

Anderson WA, Pratt I, Ryan MR, Flynn A.

Food Safety Authority of Ireland, Dublin, Ireland.

Two probabilistic models were developed to estimate the acute and chronic exposure to fluoride of exclusively formula-fed infants aged 0-4 months as a result of the consumption of infant formula reconstituted with fluoridated tap water in Ireland. The estimates were based on calculated infant formula consumption and accepted body weight standards, together with reported concentrations of fluoride in infant formula powder and measured values for the fluoride content of water in Ireland. The mean acute exposure of infants to fluoride on any single day in areas served by 387 fluoridated water supplies was estimated to be between 0.11 and 0.14 mg/kg body weight depending on age group (95th percentiles 0.2 and 0.26 mg/kg b.w., respectively). These predicted intakes were well below the intake of fluoride associated with acute toxic effects, which is considered to be 5 mg fluoride (F(-))/kg body weight. The mean chronic exposure of infants to fluoride was estimated to be between 0.106 and 0.170 mg/kg b.w./day depending on body weight (95th percentiles 0.108 and 0.172 mg/kg b.w./day, respectively). This estimate described the average daily fluoride intake of infants during the first 4 months of life residing in the areas served by 226 water supplies that achieved an average yearly fluoride concentration below 1.03 mg/l. Dental fluorosis may be considered to be the only risk at these low doses and from our work it is estimated that there is a very low risk of moderate dental fluorosis of the permanent dentition in infants exposed to fluoride at these levels. Copyright 2004 S. Karger AG, Basel

PMID: 15316185 [PubMed - in process]

Note from EC:
The age at which the infant is weaned from human milk is variable. It would have been helpful if the authors calcuated the risks to an infant weaned at six months or longer. For example, the American Academy of Pediatrics recommends the following:

• Breast-feed babies for at least a year and as long after as mother and child desire. Introduce iron-enriched solid foods at 6 months of age to complement the breast milk.
• Give babies weaned from the breast or the bottle before 12 months of age iron-fortified formula, not cow's or goat's milk.

Ref: American Academy of Pediatrics (1997). Breastfeeding and the use of human milk. Pediatrics, 100(6): 1035–1039.


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15612348

World J Orthod. 2004 Fall;5(3):268-9.

No Abstract available

Abundance of fluoride and class III malocclusions in Guadalajara, Mexico.

Evans CA.

PMID: 15612348 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15707318

Ying Yong Sheng Tai Xue Bao. 2004 Nov;15(11):2087-90.

[Changes of light energy distribution in reaction centers of Citrus unshiu leaf photosystem under different light intensities]

[Article in Chinese]

Guo Y, Song L, Xu K, Zhang L.

State Agriculture Ministry Laboratory of Horticultural Plant Growth Development and Biotechnology, Department of Horticulture, Zhejiang University, Hangzhou 310029, China. guoyping@mail.hz.zj.cn

In order to further understand the light energy distribution in photochemical reaction centers of fruit trees, this paper employed modulated fluorescence technique to study the state transition of photosystem in Citrus unshiu leaves under high and low light intensities. The results indicated that under low light intensity of 100 micromol x m(-2) s(-1), the PQ pool was in reduction state due to Q(A) reduction, which made the light energy distribution in photosystem changed from PS II to PS I; while under high light intensity of 1000 micromol x m(-2) s(-1), the PQ pool could not get electron and was in oxidation state, making light energy distribution changed from state 2 to state 1. When the leaves were treated by a phosphatase inhibitor NaF, the state 2 to state 1 transition of photosystem was inhibited under high light intensity, and the excessive light energy distribution from PS I to PS II caused damage to PS II. These findings would be helpful to understand the mechanisms of the photoinhibition of photosynthesis and the photodamage of photosynthetic apparatus of fruit trees.

PMID: 15707318 [PubMed - in process]

 

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15614922&query_hl=13

Angew Chem Int Ed Engl. 2004 Dec 27;44(2):214-31.
 
Modern synthetic methods for fluorine-substituted target molecules.

Shimizu M, Hiyama T.

Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.

Fluorine has come to be recognized as a key element in materials science: in heat-transfer agents, liquid crystals, dyes, surfactants, plastics, elastomers, membranes, and other materials. Furthermore, many fluorine-containing biologically active agents are finding applications as pharmaceuticals and agrochemicals. Progress in synthetic fluorine chemistry has been critical to the development of these fields and has led to the invention of many novel fluorinated molecules as future drugs and materials. As a result of the electronic effects of fluorine substituents, fluorinated substrates and reagents often exhibit unusual and unique chemical properties, which often make them incompatible with established synthetic methods. Thus, the problem of how to control the unusual properties of compounds with fluorine substituents deserves much attention, so as to promote the design of facile, efficient, and environmentally benign methods for the synthesis of valuable organofluorine targets.

PMID: 15614922 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15587093

J Dent Child (Chic). 2004 May-Aug;71(2):121-5.

Nails as biomarkers of fluoride in children of fluoridated communities.

Levy FM, Bastos JR, Buzalaf MA.

Department of Biological Sciences, Bauru Dental School, University of Sao Paulo, Bauru-Sao Paulo, Brazil.

PURPOSE: The objective of this study was to verify the use of nails as biomarkers of chronic fluoride (F) exposure from the diets of children living in communities with negligibly or optimally fluoridated water.
METHODS: Fifteen 2- to 6-year-old children living in Bauru-Sao Paulo (fluoridated) and 15 lifelong residents of Itapolis-Sao Paulo (nonfluoridated) participated in the study. Fluoride concentrations in nails and duplicate diet were analyzed with the electrode, following hexamethyldisiloxane (HMDS)-facilitated diffusion. Data were analyzed by student's t-test and linear regression (P < .05).
RESULTS: Mean fluoride concentrations ([microg/g) in fingernails and toenails of Bauru children were 3.56 +/- 1.3 and 2.81 +/- 1.29, respectively, and for Itapolis children 2.29 +/- 1.25 and 1.58 +/- 0.59, respectively. The differences between Bauru and Itapolis children, as well as between fluoride concentrations in fingernails and toenails, were statistically significant. The estimated fluoride intake from the diet was significantly higher for Bauru children (0.55 +/- 0.61 mg) when compared to Itapolis children (0.09 +/- 0.06 mg). A significant positive correlation was found between the mean of fingernail and toenail fluoride concentrations and estimated fluoride intake from the diet (r = 0.57).
CONCLUSIONS: This study's preliminary data suggests that fingernails and toenails may be used as biomarkers of chronic fluoride exposure from the diet. Additional studies are necessary to determine the predictive values, sensitivity, and specificity of this biomarker so that nails are used to differentiate children at the age of dental fluorosis risk and who live in communities with negligibly or optimally fluoridated water.

PMID: 15587093 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15587090

J Dent Child (Chic). 2004 May-Aug;71(2):110-3.

Risk of fluorosis associated with infant formulas prepared with bottled water.

Buzalaf MA, Damante CA, Trevizani LM, Granjeiro JM.

Department of Biological Sciences, Bauru Dental School, University of Sao Paulo, Brazil. mbuzalaf@fob.usp.br

PURPOSE: The purpose of this study was to estimate fluoride (F) intake from infant formulas prepared with different brands of bottled water.
METHODS: Fluoride concentrations in 4 samples of infant milk and soy-based formulas, commercially available in the United States, prepared with deionized water and 5 brands of bottled water, were determined after Hexamethyldisioxane (HMDS)-facilitated diffusion, in duplicate, using an F ion-specific electrode. Possible fluoride ingestion per killogram body mass was estimated, based on suggested volumes of formula consumption, for infants 1 and 12 months.
RESULTS: Fluoride concentrations ranged from 0.076 to 0.214 ppm and 0.092 to 1.053 ppm for formulas prepared with deionized and bottled water, respectively. When prepared with deionized water, none of the formulas provided an F intake above the suggested threshold for fluorosis (0.07 mg F/kg/day). However, when prepared with some brands of bottled water containing 0.623 and 0.839 ppm, all of them did provide it.
CONCLUSIONS: Some brands of bottled water usually marketed for infants and used to dilute infant formulas may increase fluoride concentrations beyond reccommended levels believed to lead to fluorosis.

PMID: 15587090 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15575447

Am J Dent. 2004 Oct;17(5):351-3.

In vivo enamel fluoride uptake after use of fluoride products.

Campus G, Lallai MR, Carboni R, Spano G, Luglie P, Garcia-Godoy F.

Dental Institute, University of Sassari, Viale San Pietro 43/C, 1-07100 Sassari, Sardinia, Italy. gcampus@uniss.it

PURPOSE: To evaluate fluoride uptake in enamel after use of products containing different fluoride components of distinct oral hygiene regimen in vivo.
METHODS: 84 healthy subjects (24 females and 60 males aged 19-26 years, mean 22.2) recruited from the students attending the courses of the Medical Faculty of the University of Sassari, Italy, were randomly assigned to one of four treatments groups:
A: treated with a dentifrice containing sodium monofluorophosphate (1250 ppm F-);
B: treated with dentifrice with 1250 ppm F- from AmF;
C: treated with an AmF toothpaste (1250 ppm F-) and a mouth rinse with 250 ppm F- from AmF; or
D: treated with a NaMFP toothpaste (1250 ppm F-) plus 1250 ppm NaMFP varnish.
Acid-etched enamel microbiopsies on the vestibular surface of the first maxillary premolar were collected at baseline (to), after 20 days of test product use (t1) and after 24 hours without treatment (t2). Fluoride concentration was measured using an ion-specific electrode. All measurements were made in triplicate and analyzed statistically using two-way factorial ANOVA for independent samples standard weighted-means analysis.
RESULTS: The fluoride uptake in the enamel shows a considerable variation between the groups. Significant differences were found both within all products in terms of fluoride concentration in enamel for (P < 0.0001 for two-way ANOVA, and later Tukey HSD test). After 20 days of treatment, the group using AmF toothpaste plus AmF mouthrinse had a higher fluoride uptake than the groups using either of the other products (P < 0.05). In conclusion, all products lead to an appreciable amount of fluoride uptake in enamel; AmF products led to higher concentrations. The concentration of fluoride accumulated during treatment phase remained high after 24 hours following the cessation of use.

PMID: 15575447 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15586828

Adv Data. 2004 Nov 9;(349):1-7.
 
Prevalence of leading types of dietary supplements used in the Third National Health and Nutrition Examination Survey, 1988--94.

Ervin RB, Wright JD, Reed-Gillette D.

Division of Health and Nutrition Examination Surveys, Hyattsville, Maryland 20782, USA.

This report presents the prevalence of the leading types of dietary supplements taken during the third National Health and Nutrition Examination Survey (NHANES III), 1988-94. Approximately 40 percent of the U.S. population 2 months of age and older reported taking some type of dietary supplement in NHANES III, and the leading supplements taken were multivitamin/multiminerals (22 percent), multivitamins plus vitamin C (15 percent), vitamin C as a single vitamin (13 percent), other dietary supplements such as herbal and botanical supplements (7 percent), and vitamin E as a single vitamin (6 percent). To some extent, the leading types of supplements and order changed after stratifying the results by sex and age groups. Other major contributors were multivitamins with iron or fluoride taken by children, iron taken by adolescent and young adult females, and calcium taken by middle-aged and elderly females. There was also a high prevalence of use of potassium among middle-aged and elderly adults but this probably reflects its use as a medication rather than as a dietary supplement. Collecting information on dietary supplement use is an important part of monitoring the nutritional status of the U.S. population.

PMID: 15586828 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15656442

Pediatr Dent. 2004;26(7):87-8.

No abstract available.

Clinical guideline on fluoride therapy.

American Academy of Pediatric Dentistry.

PMID: 15656442 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15648396

J Tenn Dent Assoc. 2004 Fall;84(4):23-30.

No abstract available.

Managing optimal fluoride therapy: the halo effect.

Weesner BW Jr.

University of Tennessee College of Dentistry in Memphis, Tennessee, USA.

PMID: 15648396 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15575291

Environ Sci Technol. 2004 Nov 1;38(21):5712-20.

Receptor modeling of toronto PM2.5 characterized by aerosol laser ablation mass spectrometry.

Owega S, Khan BU, D'Souza R, Evans GJ, Fila M, Jervis RE.

Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada.

Urban Toronto fine particulate matter (PM2.5) was physically and chemically characterized by online aerosol laser ablation mass spectrometry (LAMS) between January 2002 and February 2003. The mass spectra from the analysis of individual aerosol particles were classified according to chemical composition by a neural network approach called adaptive resonance theory (ART-2a). Temporal trends of the hourly analysis rate of over 120 different particles types were constructed and subjected to positive matrix factorization (PMF). This receptor modeling technique enabled the identification of nine distinct emission sources responsible for these particle types: biogenic, mixed crustal, organic nitrate, construction dust, Toronto soil/road salt, secondary salt, wood burning, intercontinental dust, and an unknown source of aluminum fluoride dust. Episodic events occurred with the wood burning, intercontinental dust, and unknown dust sources. This is the first paper reporting the application of PMF to single-particle spectral data.

PMID: 15575291 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15575447

Am J Dent. 2004 Oct;17(5):351-3.

In vivo enamel fluoride uptake after use of fluoride products.

Campus G, Lallai MR, Carboni R, Spano G, Luglie P, Garcia-Godoy F.

Dental Institute, University of Sassari, Viale San Pietro 43/C, 1-07100 Sassari, Sardinia, Italy. gcampus@uniss.it

PURPOSE: To evaluate fluoride uptake in enamel after use of products containing different fluoride components of distinct oral hygiene regimen in vivo.
METHODS: 84 healthy subjects (24 females and 60 males aged 19-26 years, mean 22.2) recruited from the students attending the courses of the Medical Faculty of the University of Sassari, Italy, were randomly assigned to one of four treatments groups: A: treated with a dentifrice containing sodium monofluorophosphate (1250 ppm F-); B: treated with dentifrice with 1250 ppm F- from AmF; C: treated with an AmF toothpaste (1250 ppm F-) and a mouth rinse with 250 ppm F- from AmF; or D: treated with a NaMFP toothpaste (1250 ppm F-) plus 1250 ppm NaMFP varnish. Acid-etched enamel microbiopsies on the vestibular surface of the first maxillary premolar were collected at baseline (to), after 20 days of test product use (t1) and after 24 hours without treatment (t2). Fluoride concentration was measured using an ion-specific electrode. All measurements were made in triplicate and analyzed statistically using two-way factorial ANOVA for independent samples standard weighted-means analysis.
RESULTS: The fluoride uptake in the enamel shows a considerable variation between the groups. Significant differences were found both within all products in terms of fluoride concentration in enamel for (P < 0.0001 for two-way ANOVA, and later Tukey HSD test). After 20 days of treatment, the group using AmF toothpaste plus AmF mouthrinse had a higher fluoride uptake than the groups using either of the other products (P < 0.05). In conclusion, all products lead to an appreciable amount of fluoride uptake in enamel; AmF products led to higher concentrations. The concentration of fluoride accumulated during treatment phase remained high after 24 hours following the cessation of use.

PMID: 15575447 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15562941

J Public Health Dent. 2004 Fall;64(4):198-204.

Seasonal variation in fluoride intake: the Iowa fluoride study.

Broffitt B, Levy SM, Warren JJ, Heller KE.

Department of Preventive and Community Dentistry, College of Dentistry, University of Iowa, Iowa City 52242, USA. barbara-broffitt@uiowa.edu

OBJECTIVES: Although patterns of fluid intake change seasonally, little is known about how fluoride intake varies by season. Since even short-term increases in fluoride intake could potentially lead to more dental fluorosis, it is valuable to assess the degree of seasonal variation to determine if it increases fluoride intake to levels that could be considered a concern in young children.
METHODS: Questionnaires were mailed periodically to participants in the Iowa Fluoride Study beginning at 6 weeks of age and continuing for a number of years. Parents recorded the date; child's weight; estimates of the amounts of water and other beverages that their child consumed per week; the type and amount of any fluoride supplements used; and the type, amount, and frequency of dentifrice used, with an estimate of the proportion of dentifrice that was swallowed. Documented water fluoride levels from municipal sources and assay of individual sources were linked to water intake amounts. Total fluoride intake per kg body weight was estimated from water, other beverages, fluoride supplements, and ingested dentifrice. Generalized linear models compared temperature-related and seasonal effects after adjusting for the child's age.
RESULTS: Separate analyses for ages 0-12 months and 12-72 months showed different results. Children younger than 12 months of age did not exhibit significant seasonal or temperature-related variation in any of the components of fluoride intake. Children aged 12-72 months had higher fluoride intake (mg F/kg bw) from beverages in summer (P<.05), and fluoride intake from beverages increased with monthly temperature (P<.001).
CONCLUSIONS: Fluoride intake from beverages for children aged 12-72 months is slightly higher in the summer and increases with mean monthly temperature. Fluoride intake from supplements and dentifrice did not change significantly with either season or temperature.

PMID: 15562941 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15606059

Am Fam Physician. 2004 Dec 1;70(11):2113-20.

A practical guide to infant oral health.

Douglass JM, Douglass AB, Silk HJ.

University of Connecticut School of Dental Medicine, Farmington, Connecticut, USA.

Early childhood caries is the most common chronic disease in young children and may develop as soon as teeth erupt. Bacteria, predominately mutans streptococci, metabolize simple sugars to produce acid that demineralizes teeth, resulting in cavities. Physicians should examine children's teeth for defects and cavities at every well-child visit. Any child with significant risk factors for caries (e.g., inadequate home dental care and poor oral hygiene, a mother with a high number of cavities, a high sugar intake, enamel defects, premature birth, special health care needs, low socioeconomic status) should be referred to a dentist by 12 months of age. Promoting appropriate use of topical and systemic fluoride and providing early oral hygiene instruction can help reduce caries in young patients, as can regularly counseling parents to limit their child's consumption of sugar.

PMID: 15606059 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15552604

J Drugs Dermatol. 2004 Sep-Oct;3(5):522-5.

The excimer lasers.

Spencer JM, Hadi SM.

The Mount Sinai Medical Center, New York, New York 10029, USA. James.M.Spencer@msnyuhealth.org

The excimer lasers are a group of lasers that have found wide application in a variety of medical fields including dermatology, cardiology, ophthalmology, and orthopedics. The word excimer refers to excited dimer. These lasers operate in the ultraviolet range, and examples include the 193 nm argon-fluroide, 248 nm krypton-fluoride, 351 nm xenon-fluoride, and of particular interest to dermatology, the 308 nm xenon-chloride. These lasers utilize a mixture of a noble gas and a halogen as a lasing material. They were first used in medicine for their ability to produce cold tissue ablation, but more recently have been used in dermatology as a method of non-ablative phototherapy.

PMID: 15552604 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15593170

Angew Chem Int Ed Engl. 2004 Dec 10;43(48):6653-6656.

No Abstract available
 
Amorphous Aluminum Bromide Fluoride (ABF).

Krahl T, Kemnitz E.

Institut fur Chemie, Humboldt-Universitat zu Berlin, Brook-Taylor-Strasse 2, 12489 Berlin, Germany, Fax: (+49) 30-2093-7277.

PMID: 15593170 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15513419

Acta Odontol Scand. 2004 Aug;62(4):223-30.

Caries-preventive effect of sodium fluoride mouthrinses: a systematic review of controlled clinical trials.

Twetman S, Petersson L, Axelsson S, Dahlgren H, Holm AK, Kallestal C, Lagerlof F, Lingstrom P, Mejare I, Nordenram G, Norlund A, Soder B.

Department of Odontology, Pediatric Dentistry, Faculty of Medicine, Umea University, SE-901 87 Umea, Sweden. svante.twetman@udont.umu.se

The Swedish Council on Technology Assessment in Health Care launched a project group in 1999 to systematically review and evaluate the existing literature on different caries-preventive methods. The aim of this article was to report the findings concerning the caries-preventive effect of fluoride mouthrinses (FMRs) in various age groups, with special reference to background fluorides. A systematic search in electronic databases for literature published between 1966 and August 2003 was conducted with the inclusion criteria of a randomized or controlled clinical trial, at least 2 years' follow-up, and caries increment in the permanent dentition (DeltaDMFS/T) as endpoint. Out of 174 articles originally identified, 62 met the inclusion criteria. These studies were assessed independently by at least two reviewers and scored A-C according to predetermined criteria for methodology and performance. The measure of effect was the prevented fraction (PF) expressed as percent. The level of evidence was based on 25 articles. The results revealed limited evidence (evidence level 3) for the caries-preventive effect (PF 29%) of daily or weekly sodium fluoride rinses compared with placebo in permanent teeth of schoolchildren and adolescents with no additional fluoride exposure and for a caries-preventive effect on root caries in older adults. Inconclusive evidence (evidence level 4) was found regarding the effect of FMRs in schoolchildren and adolescents exposed to additional fluoride sources such as daily use of fluoride toothpaste. No firm support for the use of FMRs was disclosed in a small number of studies designed for patients at caries risk. Furthermore, no association between the frequency of the rinses and prevented fraction or saved surfaces per year was found. In conclusion, this systematic review suggests that sodium fluoride mouthrinses may have an anti-caries effect in children with limited background of fluoride exposure, while its additional effect in children with daily use of fluoride toothpaste could be questioned. The need for further clinical trials to elucidate the effect of FMRs in risk patients and older adults is emphasized.

PMID: 15513419 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15503849

Int Dent J. 2004 Oct;54(5):256-60.

Is the fluoride level in drinking water a gold standard for the control of dental caries?

Khan AA, Whelton H, O'Mullane D.

Shaikh Zayed Federal Postgraduate Medical Institute, Lahore, Pakistan. ayyazk@brain.net.pk

AIM: To obtain baseline knowledge of levels of dental caries in 12-year-old children residing in areas with varying levels of fluoride in drinking water in Pakistan; and to observe a dose-response relationship between the prevalence of dental caries at different concentrations of fluoride in drinking water.
METHOD: Clinical examination of children and analysis of samples of drinking water.
RESULTS: The maximum reduction of caries in relation to fluoride levels in Pakistan was witnessed between the fluoride concentrations of 0.00-0.33ppm.
CONCLUSIONS: There are no gold standards for setting up a universal optimal level of fluoride in drinking water and each country needs to determine the concentration of fluoride in their drinking water in accordance with its socio-economic and climatic conditions, dietary and oral hygiene habits of its population, and local research to determine how much fluoride is beneficial in the control of caries.

PMID: 15503849 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15503846

Int Dent J. 2004 Oct;54(5):235-9.

Prevalence of dental fluorosis in rural areas of Davangere, India.

Chandrashekar J, Anuradha KP.
sekarcandra@hotmail.com

OBJECTIVES: To assess the prevalence and severity of dental fluorosis and its relationship with fluoride levels in drinking water.
DESIGN: Twelve villages with similar climate, diet, socioeconomic conditions and altitudes were selected from rural areas of Davangere district, Karnataka, India. The fluoride concentration in drinking water was estimated by the Ion Selective Electrode Method. Dean's Index was used to assess the dental fluorosis. Karl-Pearson coefficient for correlation and simple regression analysis were used to evaluate the association between the water fluoride levels and the community fluorosis index (CFI).
RESULTS: The study group consisted of 1,131, 12-15-year-old school children. The fluoride levels in drinking water of selected villages were in the range of 0.22-3.41ppm. A stepwise increase in the prevalence of dental fluorosis with corresponding increase in water fluoride content, 13.2% at 0.22ppm F to 100% at 3.41 ppm F, was found. There was a significant positive linear correlation (r=0.99) between CFI and water fluoride level.
CONCLUSION: Dental fluorosis is a major dental public health problem among children in Davangere district and is related to drinking water with 0.74ppm fluoride or above.

PMID: 15503846 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15504475

Chemosphere. 2004 Dec;57(9):1157-1163.
 
Effects of experimental parameters on NF(3) decomposition fraction in an oxygen-based RF plasma environment.

Wang YF, Wang LC, Shih M, Tsai CH.

Department of Bioenvironmental Engineering, Chung Yuan Christian University, No. 22, Pu-Jen, Pu-Chung Li, Chung-Li 320, Taiwan, ROC; Department of Environmental Engineering and Science, Chia-Nan University of Pharmacy and Science, No. 60, Sec. 1, Erh-Jen Rd., Tainan 717, Taiwan, ROC.

Clean procedure is one of the major emitters of perfluorinated compounds (PFCs) in semiconductor manufacturing. Nitrogen trifluoride (NF(3)) is increasingly the process gas of choice for eliminating PFC emissions. However, its toxic to human and similar global warming potential compared to most other PFCs made NF(3) warranted much more investigation. This study demonstrated a radio-frequency plasma system for decomposing NF(3). The effects of experimental parameters: input power, O(2)/NF(3) ratio, operational pressure and NF(3) feeding concentration on NF(3) decomposition fraction [Formula: see text] and energy efficiency [Formula: see text] were examined in detail. The analytical results demonstrated that the NF(3) was almost completely decomposed (>99%) at input power=30W, [NF(3)](in)=1.0% and [Formula: see text] increased with input power. However, adding O(2) to the system inhibited NF(3) decomposition and decreased [Formula: see text] . Moreover, [Formula: see text] and [Formula: see text] decreased with gradually increasing operational pressure. Notably, increasing the NF(3) feeding concentration increased molecule density, reducing [Formula: see text] , but increasing [Formula: see text] . Furthermore, the products detected in the NF(3)/O(2)/Ar plasma system were NO(2), NO, N(2)O, SiF(4), N(2) and F(2). Potential reaction pathways in the oxygen-based NF(3) plasma environment were built-up and elucidated.

PMID: 15504475 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15491085

J Indian Soc Pedod Prev Dent. 2004 Jun;22(2):49-53.

Prevalence of DMFT and fluorosis in the students of Dayer city (Iran).

Ramezani GH, Valaei N, Eikani H.

Dental School of Islamic Azad University, Tehran, Iran.

The survey was performed using the cross-sectional method on 506 students selected using multi-stage random sampling. The fluorosis level according to Deans classification and DMFT with its standard method were surveyed. The water fluoride level was estimated in 6 town sources twice, using Alizarin chemical method. The fluorosis and DMFT prevalence in the samples was determined. A total number of 506 students (55.6% boys and 44.4% girls) aged 13 +/- 3 years were examined. The water fluoride level was 2.43 +/- 0.23 ppm and in all the samples, which was more than normal. 19.9% of the subjects being surveyed were healthy 43.6% had mild, 25% moderate and 11.5% had severe fluorosis. Severe fluorosis was found in 65.8% of girls and 34.2% of boys (p < 0.05). The mean DMFT value was 1.8 +/- 1.73 and was higher in girls in comparison with boys (p < 0.05).

PMID: 15491085 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15473086

Int J Occup Environ Health. 2004 Jul-Sep;10(3):310-2.

Fluoride exposure and respiratory symptoms in welders.

Sjogren B.

Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. Bengt.Sjogren@imm.ki.se

Welders inhale gases and respirable particles. To investigate the relationship between fluoride exposure and respiratory symptoms in welders using basic electrodes containing calcium fluoride, 63 railroad track welders were interviewed. Fluoride was measured in post-shift urine samples. Seventeen welders reported respiratory symptoms related to welding fume exposures. Respiratory symptoms were somewhat more common with increasing concentrations of fluoride in urine. The association between welding fume exposure and respiratory symptoms seems related more to fluorides than to other particles among welders using basic electrodes.

PMID: 15473086 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15461170

Environ Sci Technol. 2004 Sep 1;38(17):4612-8.

Emissions of air pollutants from household stoves: honeycomb coal versus coal cake.

Ge S, Xu X, Chow JC, Watson J, Sheng Q, Liu W, Bai Z, Zhu T, Zhang J.

Am-As Corporation, Portland, Oregon, USA.

Domestic coal combustion can emit various air pollutants. In the present study, we measured emissions of particulate matter (PM) and gaseous pollutants from burning a specially formulated honeycomb coal (H-coal) and a coal cake (C-coal). Flue gas samples for PM2.5, PM coarse (PM2.5-10), and TSP were collected isokinetically using a cascade impactor; PM mass concentrations were determined gravimetrically. Concentrations of SO2, NOx, and ionic Cr(VI) in PM were analyzed using spectrometric methods. Fluoride concentrations were measured using a specific ion electrode method. PM elemental components were analyzed using an X-ray fluorescence technique. Total (gas and particle phase) benzo[a]pyrene (BaP) concentration was determined using an HPLC/fluorescence method. Elemental and organic carbon contents of PM were analyzed using a thermal/optical reflectance technique. The compositional and structural differences between the H-coal and C-coal resulted in different emission characteristics. In generating 1 MJ of delivered energy, the H-coal resulted in a significant reduction in emissions of SO2 (by 68%), NOx (by 47%), and TSP (by 56%) as compared to the C-coal, whereas the emissions of PM2.5 and total BaP from the H-coal combustion were 2-3-fold higher, indicating that improvements are needed to further reduce emissions of these pollutants in developing future honeycomb coals. Although the H-coal and the C-coal had similar emission factors for gas-phase fluoride, the H-coal had a particle-phase fluoride emission factor that was only half that of the C-coal. The H-coal had lower energy-based emissions of all the measured toxic elements in TSP but higher emissions of Cd and Ni in PM2.5.

PMID: 15461170 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15475618

Biol Trace Elem Res. 2004 Sep;100(3):195-204.
 
Mineral content of water and food in fluorotic villages and prevalence of dental fluorosis.

Bhargavi V, Khandare AL, Venkaiah K, Sarojini G.

National Institute of Nutrition (ICMR), Hyderabad-500007, India.

The fluoride (F), calcium (Ca), magnesium (Mg), zinc (Zn), copper (Cu), and phosphorus (P) content in potable water and food samples from endemic and nonendemic villages for fluorosis were analyzed. It was found that the F content in water was significantly higher (p<0.01) in endemic villages (4.20+/-1.6 ppm) than control villages (0.63+/-0.15 ppm), whereas the Ca, Cu, and Mg contents were found to be significantly lower (p<0.05) in endemic villages compared to control villages. However, there was no significant difference in Zn and P contents between the villages. Foods grown in endemic villages contained significantly higher (p<0.01) fluoride content as compared to control villages. There was no significant difference in Ca, Mg, P, and Zn contents in food grown in endemic and control villages. Copper content in cereals (p<0.05), pulses (p<0.01), and vegetables (p<0.01) in endemic villages was found significantly higher as compared to control villages. The overall prevalence of dental fluorosis in six endemic villages was 97.4% in boys and 96% in girls, which was significantly higher (p<0.01) than that of control villages, where it was 10.5% in boys and 8.3% in girls. The prevalence of dental fluorosis was positively correlated (r=0.125, p<0.01) to fluoride and negatively correlated to Ca and Cu content in drinking water in endemic villages.

PMID: 15475618 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15384727

J Water Health. 2004 Mar;2(1):23-35.

Fluorides in groundwater, soil and infused black tea and the occurrence of dental fluorosis among school children of the Gaza strip.

Shomar B, Muller G, Yahya A, Askar S, Sansur R.

Institute of Environmental Geochemistry, University of Heidelberg, Im Neuenheimer Feld 236, 69120 Heidelberg, Germany. bshomar@ugc.uni-heidelberg.de

The purpose of this study was to determine the fluoride levels in water, soil and tea, and to identify the major fluoride minerals in soil that supply water with fluoride ions. Another aim was to study the prevalence of dental fluorosis in permanent dentition of the school children of the Gaza Strip. Monitoring of fluoride levels in 73 groundwater wells and 20 topsoil samples for the last three years revealed a general trend of increasing from north to south of the Gaza Strip. A linear regression analysis found a correlation coefficient of r=0.93 between the fluoride concentrations in groundwater and soil for the same geographic areas. However, the X-ray diffraction technique (XRD) results showed that none of the four major fluoride minerals were detected in the tested soil samples; the PHREEQC model showed that fluorite (CaF2) was the main donating mineral of fluoride ions to groundwater. A high positive correlation was found between fluoride concentrations in groundwater and occurrence of dental fluorosis. Among 353 school children of the five geographic areas of the Gaza Strip the prevalence of dental fluorosis was 60%, and 40% had no signs of fluorosis in their permanent dentitions. The highest occurrence, 94%, was in Khan Yunis, followed by 82% in Rafah, 68% in the middle area, 29% in Gaza and the lowest occurrence of 9% was in the northern area. These percentages were directly proportional to the average content of fluoride in groundwater of each area: 2.6, 0.9, 1.7, 1.2, and 0.7 ppm, respectively. The exception was Rafah where people drank from new groundwater wells that have been dug in the last 10 years. The occurrence of the disease was due to intake of high amounts of fluorides in drinking water, tea and fish. Communication with population indicated a heavy intake of tea starting from a very young age; not uncommonly tea is put in nursing bottles. No significant correlation was found between prevalence figures and gender or age groups. This high prevalence indicates a need to examine other sources of F including diet.

PMID: 15384727 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15373364

J Air Waste Manag Assoc. 2004 Aug;54(8):960-70.

Abatement of sulfur hexafluoride emissions from the semiconductor manufacturing process by atmospheric-pressure plasmas.

Lee HM, Chang MB, Wu KY.

Graduate Institute of Environmental Engineering, National Central University, Taiwan.

Sulfur hexafluoride (SF6) is an important gas for plasma etching processes in the semiconductor industry. SF6 intensely absorbs infrared radiation and, consequently, aggravates global warming. This study investigates SF6 abatement by nonthermal plasma technologies under atmospheric pressure. Two kinds of nonthermal plasma processes--dielectric barrier discharge (DBD) and combined plasma catalysis (CPC)--were employed and evaluated. Experimental results indicated that as much as 91% of SF6 was removed with DBDs at 20 kV of applied voltage and 150 Hz of discharge frequency for the gas stream containing 300 ppm SF6, 12% oxygen (O2), and 40% argon (Ar), with nitrogen (N2) as the carrier gas. Four additives, including Ar, O2, ethylene (C2H4), and H2O(g), are effective in enhancing SF6 abatement in the range of conditions studied. DBD achieves a higher SF6 removal efficiency than does CPC at the same operation condition. But CPC achieves a higher electrical energy utilization compared with DBD. However, poisoning of catalysts by sulfur (S)-containing species needs further investigation. SF6 is mainly converted to SOF2, SO2F4, sulfur dioxide (SO2), oxygen difluoride (OF2), and fluoride (F2). They do not cause global warming and can be captured by either wet scrubbing or adsorption. This study indicates that DBD and CPC are feasible control technologies for reducing SF6 emissions.

PMID: 15373364 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15371213

J Toxicol Environ Health A. 2004 Oct 22-Nov 26;67(20-22):1741-53.

Environmental evaluation of fluoride in drinking water at "Los Altos de Jalisco," in the central Mexico region.

Hurtado R, Gardea-Torresdey J.

Naturally occurring fluoride has been detected and quantified in drinking water in several cities of the "Los Altos de Jalisco" (LAJ) region. LAJ is located in the northeastern part of the state of Jalisco-Mexico, covering an area of 16,410 km2 with a population of 696,318 in 20 municipalities. Drinking water comes mainly from groundwater aquifers, located in the Trans-Mexican Volcanic Belt, which is a volcanic region characterized by hydrothermal activity. Results indicated that water supply from 42% of the municipalities had a fluoride concentration over the Mexican standards of 1.5 mg/L. It is important to notice that there are three cities, Lagos de Moreno (1.66-5.88 mg/L F-), Teocaltiche (3.82-18.58 mg/L F-), and Encarnacion de Diaz (2.58-4.40 mg/L F-) where all water samples resulted in fluoride concentration over the maximum contaminant level. The total population from these three cities is over 122,000 inhabitants. Another important city with high levels of fluoride in the water supply was Tepatitlan de Morelos (2 wells with 6.54 and 13.47 mg/L F-). In addition to water supply, 30 samples of brand-name bottled water were tested. Surprisingly, 8 samples (27%) demonstrated fluoride level over the standards, mainly Agua de Lagos with 5.27 mg/L. Fluoridated table salt (200-300 mg/kg F-) is another important source of fluoride. A large number of people living in the region, mainly school children, might be under adverse health risk because they are consuming contaminated drinking water. It is well known that long-term exposure to water with high levels of fluoride produces severe health problems.

PMID: 15371213 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15370637

Acta Odontol Scand. 2004;62(3):163-169.

Effect of combined caries-preventive methods: a systematic review of controlled clinical trials.

Axelsson S, Soder B, Nordenram G, Petersson L, Dahlgren H, Norlund A, Kallestal C, Mejare I, Lingstrom P, Lagerlof F, Holm AK, Twetman S.

The aim of this systematic review was to evaluate the caries-preventive effect of combined caries-preventive methods, defined as two or more different interventions in combination, each expected to prevent dental caries. The Medline database was searched for articles published in the period January 1966 to June 2003. Twenty-four controlled studies met the inclusion criteria, and their value as evidence was assessed according to predetermined criteria. The level of evidence for the overall conclusion regarding each method was graded according to the protocol of the Swedish Council on Technology Assessment in Health Care. The scientific evidence for the combination of treatments involving fluoride that had a preventive effect on caries in children and adolescents was graded as moderate. However, for elderly patients the scientific evidence for the caries-preventive effect of different combinations of treatments was found to be incomplete. No conclusion could be drawn regarding the evidence for combinations of treatments being effective for groups at high caries risk, as the results from the identified clinical studies were conflicting.

PMID: 15370637 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15370638

Acta Odontol Scand. 2004;62(3):170-176.

Professional fluoride varnish treatment for caries control: a systematic review of clinical trials.

Petersson L, Twetman S, Dahlgren H, Norlund A, Holm AK, Nordenram G, Lagerlof F, Soder B, Kallestal C, Mejare I, Axelsson S, Lingstrom P.

The aim of this paper was systematically to evaluate the caries-preventive effect of professional fluoride varnish treatments. A search of the literature for articles published between 1966 and August 2003 was carried out in electronic databases, reference lists of articles, and selected textbooks in accordance with the strategy of the Swedish Council on Technology Assessment in Health Care. Out of 302 identified papers, 24 randomized and controlled clinical trials comparing fluoride varnish with placebo, no active treatment or other fluoride preventive regimens of at least 2 years' study duration were included. The trials that met the inclusion criteria were assessed independently and systematically by at least two reviewers and scored from A to C according to predetermined criteria for methodology and performance. The main outcome measure was the preventive fraction expressed as a percentage. The results displayed limited evidence (evidence level 3) for the caries preventive effect of topical applications of fluoride varnishes in permanent teeth. The average prevented fraction was 30% (0-69%) when compared with untreated controls. Inconclusive evidence (evidence level 4) was found for fluoride varnish treatment in the primary dentition and in adults. This systematic review reinforces the need for future clinical research of high quality, incorporating modern concepts of clinical performance and evaluation to assess dental caries control using professional fluoride varnish.

PMID: 15370638 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15369321

Rev Environ Contam Toxicol. 2004;183:21-54.

Cyanide hazards to plants and animals from gold mining and related water issues.

Eisler R, Wiemeyer SN.

US Geological Survey, Patuxent Wildlife Research Center, 11510 American Holly Drive, Laurel, Maryland 20708-4019, USA.

Cyanide extraction of gold through milling of high-grade ores and heap leaching of low-grade ores requires cycling of millions of liters of alkaline water containing high concentrations of potentially toxic sodium cyanide (NaCN), free cyanide, and metal-cyanide complexes. Some milling operations result in tailings ponds of 150 ha and larger. Heap leach operations that spray or drip cyanide onto the flattened top of the ore heap require solution processing ponds of about 1 ha in surface area. Puddles of various sizes may occur on the top of heaps, where the highest concentrations of NaCN are found. Solution recovery channels are usually constructed at the base of leach heaps, some of which may be exposed. All these cyanide-containing water bodies are hazardous to wildlife, especially migratory waterfowl and bats, if not properly managed. Accidental spills of cyanide solutions into rivers and streams have produced massive kills of fish and other aquatic biota. Freshwater fish are the most cyanide-sensitive group of aquatic organisms tested, with high mortality documented at free cyanide concentrations >20 microg/L and adverse effects on swimming and reproduction at >5 microg/L. Exclusion from cyanide solutions or reductions of cyanide concentrations to nontoxic levels are the only certain methods of protecting terrestrial vertebrate wildlife from cyanide poisoning; a variety of exclusion/cyanide reduction techniques are presented and discussed. Additional research is recommended on (1) effects of low-level, long-term, cyanide intoxication in birds and mammals by oral and inhalation routes in the vicinity of high cyanide concentrations; (2) long-term effects of low concentrations of cyanide on aquatic biota; (3) adaptive resistance to cyanide; and (4) usefulness of various biochemical indicators of cyanide poisoning. To prevent flooding in mine open pits, and to enable earth moving on a large scale, it is often necessary to withdraw groundwater and use it for irrigation, discharge it to rapid infiltration basins, or, in some cases, discharge it to surface waters. Surface waters are diverted around surface mining operations. Adverse effects of groundwater drawdown include formation of sinkholes within 5 km of groundwater drawdown; reduced stream flows with reduced quantities of wate available for irrigation, stock watering, and domestic, mining and milling, and municipal uses; reduction or loss of vegetation cover for wildlife, with reduced carrying capacity for terrestrial wildlife; loss of aquatic habitat for native fishes and their prey; and disruption of Native American cultural traditions. Surface discharge of excess mine dewatering water and other waters to main waterways may contain excess quantities of arsenic, total dissolved solids, boron, copper, fluoride, and zinc. When mining operations cease, and the water pumps are dismantled, these large open pits may slowly fill with water, forming lakes. The water quality of pit lakes may present a variety of pressing environmental problems.
PMID: 15369321 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15341615

Community Dent Oral Epidemiol. 2004 Oct;32(5):319-21.

Effective use of fluorides for the prevention of dental caries in the 21st century: the WHO approach.

Petersen PE, Lennon MA.

Oral Health Programme, World Health Organization, Geneva, Switzerland.

Despite great improvements in the oral health of populations across the world, problems still persist particularly among poor and disadvantaged groups in both developed and developing countries. According to the World Oral Health Report 2003, dental caries remains a major public health problem in most industrialized countries, affecting 60-90% of schoolchildren and the vast majority of adults. Although it appears that dental caries is less common and less severe in developing countries of Africa, it is anticipated that the incidence of caries will increase in several countries of that continent, due to changing living conditions and dietary habits, and inadequate exposure to fluorides. Research on the oral health effects of fluoride started around 100 years ago; the focus has been on the link between water and fluorides and dental caries and fluorosis, topical fluoride applications, fluoride toothpastes, and salt and milk fluoridation. Most recently, efforts have been made to summarize the extensive database through systematic reviews. Such reviews concluded that water fluoridation and use of fluoride toothpastes and mouthrinses significantly reduce the prevalence of dental caries. WHO recommends for public health that every effort must be made to develop affordable fluoridated toothpastes for use in developing countries. Water fluoridation, where technically feasible and culturally acceptable, has substantial advantages in public health; alternatively, fluoridation of salt and milk fluoridation schemes may be considered for prevention of dental caries.

PMID: 15341615 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15368398

Angew Chem Int Ed Engl. 2004 Mar 5;43(11):1322.
 
V. Percec Receives ACS Award in Polymer Chemistry / G. K. S. Prakash Receives Award for Fluorine Chemistry / N. Turro Receives ACS Award in Chemical Education.

[No authors listed]

No Abstract available

PMID: 15368398 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15316641

Anaesthesist. 2004 Aug 17 [Epub ahead of print]
 
[Hydrofluoric acid burns. A rare chemical emergency situation]

[Article in German]

Richter H, Hollenberg S, Sachs HJ, Oeltjenbruns J, Weimann J.

Klinik fur Anaesthesiologie und operative Intensivmedizin, Charite-Universitatsmedizin Berlin, Campus Benjamin Franklin.

Burns caused by hydrofluoric acid can be life-threatening. Of special significance is the often underestimated local and sometimes delayed deep action of the highly diffusible free fluoride ions and the accompanying systemic toxicity. The specific antidote calcium gluconate can be topically applied, injected into tissue or infused intra-arterially. Because of the extreme danger of systemic toxicity even after seemingly trivial injuries, monitoring in the intensive care station, especially by measuring the calcium concentration in blood and electrocardiography, and therapy is recommended.

PMID: 15316641 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15238950

Evid Based Dent. 2004;5(2):39.

Water fluoridation and Down's syndrome evidence inconclusive.

Bebermeyer RD.

1Department of Restorative Dentistry and Biomaterials, University of Texas Health Science Center at Houston - Dental Branch, Houston, TX 77030, USA.

DATA SOURCES: A qualified librarian searched 25 specialist databases, including Medline, Embase, Toxline and the Current Contents Science Citation Index, from database inception to February 2000. In addition, searches of Index Medicus (1945-1959) and Excerpta Medica (1955-1973) were undertaken by hand. Additional references were sought from individuals and organisations through a dedicated website for this review [www.york.ac.uk/inst/crd/fluoride.htm] [Note from FAN: this site not available as of July 11, 2004], and through members of a specifically designated advisory panel. Published and unpublished studies in any language were included.
STUDY SELECTION: All study designs were included that compared the incidence of Down's syndrome in populations where different levels of fluoride occurred in water supplies, either naturally or added artificially.
DATA EXTRACTION AND SYNTHESIS: Two reviewers independently assessed each paper for inclusion, and disagreements were resolved through consensus. A qualitative analysis was conducted. RESULTS: The six studies included were all ecological in design and had poor validity scores. The estimates of the crude relative risk ranged from 0.84 to 3.0. Four studies showed no significant association between the incidence of Down's syndrome and water fluoride level whereas two studies by the same author found a significant (P<0.05) positive association (increased Down's syndrome incidence with increased water fluoride level). Only two of the studies controlled for confounding factors and only one of these presented summary outcome measures.
CONCLUSIONS: The evidence of an association between water fluoride level and Down's syndrome incidence is inconclusive. The quality of the studies included in the review was relatively low, however, and further high quality research is needed.

PMID: 15238950 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15237954

J Agric Food Chem. 2004 Jul 14;52(14):4472-6.
 
Fluoride content in tea and its relationship with tea quality.

Lu Y, Guo WF, Yang XQ.

Department of Tea Science, Zhejiang University, 268 Kaixuan Road, and Department of Chemistry, Zhejiang University, 38 Zheda Road, Hangzhou 310027, People's Republic of China.

The tea plant is known as a fluorine accumulator. Fluoride (F) content in fresh leaves collected from 14 plantations in China was investigated. The F increased with maturity, and the F variation was remarkable in the tender shoots. Furthermore, significant negative relationships were observed between F content and the content of the quality parameters total polyphenols and amino acids. These substances are rich in young leaves and poor in mature ones. With regard to quality of tea products, the relationship with F content was studied using 12 brands of tea products in four categories: green tea, oolong tea, black tea, and jasmine tea collected from six provinces. The F level increased with the decline in quality and showed good correlation with the quality grades. The results suggest that the F content could be used as a quality indicator for tea evaluation.

PMID: 15237954 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15290267

Eur J Pediatr. 2004 Jul 28 [Epub ahead of print]
 
Fluoride content of mineral waters on the Belgian market and a case report of fluorosis induced by mineral water use.

Bottenberg P.

Dental School, Free University of Brussels (VUB), Laarbeeklaan 103, 1090, Brussels, Belgium.

No Abstract available

PMID: 15290267 [PubMed - as supplied by publisher]


Free full report available at
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-89102004000300018&tlng=en&lng=en&nrm=iso

Rev Saude Publica. 2004 Jun;38(3):459-65. Epub 2004 Jul 08.
 
[Evaluation of the fluoride concentration and consumption of mineral water]

[Article in Portuguese]

Ramires I, Grec RH, Cattan L, Moura PG, Lauris JR, Buzalaf MA.

Departamento de Odontopediatria, Ortodontia e Saude Coletiva, Faculdade de Odontologia de Bauru, Universidade de Sao Paulo, Bauru, SP, Brasil.

OBJECTIVE: Considering that water is an importance source of fluoride intake, and that the consumption of mineral water and prevalence of dental fluorosis have been increasing, the aim of this study was to evaluate the consumption of mineral water and its fluoride concentration.
METHODS: The study was performed in residential districts of the municipality of Bauru, State of Sao Paulo, by means of stratified sampling via clusters. Each cluster corresponded to one residential block. For randomization purposes, the residential blocks were numbered within the 17 districts established by the city plan. One thousand homes were thus visited. Mineral water samples were collected using previously labeled 50 ml plastic flasks. Fluoride analysis was done using an ion-sensitive electrode (Orion 9609), after buffering using TISAB II. Information on the consumption of mineral water was obtained by means of applying a questionnaire.
RESULTS: Around 29.72% of the city's population was consuming mineral water. In the 260 samples analyzed from 29 different brands of water, the fluoride concentration ranged from 0.045 to 1.515 mg/l. For one brand, the label stated that the fluoride concentration was 0.220 mg/l, but analysis revealed a concentration of 1.515 mg/l. Moreover, some brands did not specify the fluoride concentration on the label and, for these, the analysis showed concentrations ranging from 0.049 to 0.924 mg/l.
CONCLUSIONS: The results demonstrated wide variation in fluoride concentrations and reinforce the importance of the control of such waters by the sanitary surveillance agency.

PMID: 15243678 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15242382

Int J Paediatr Dent. 2004 Jul;14(4):260-6.

Fluoride content in bottled waters, juices and carbonated soft drinks in Mexico City, Mexico.

Jimenez-Farfan MD, Hernandez-Guerrero JC, Loyola-Rodriguez JP, Ledesma-Montes C.

Departamento de Inmunologia, Division de Estudios de Posgrado e Investigacion, Facultad de Odontologia, Universidad Nacional Autonoma de Mexico, Mexico City.

Summary.
Objective. The objective of this study was to analyse 283 samples of soft drinks available in the metropolitan market of Mexico City, Mexico: 105 juices, 101 nectars, 57 carbonated drinks and 20 bottled waters.
Materials and methods. Samples of the beverages were analysed using an Orion 720A potentiometer and an Orion 9609BN F ion-specific electrode.
Results. Fluoride concentration in the above-mentioned products ranged from 0.07 to 1.42 p.p.m. It was found that fluoride concentrations varied according to the brand, flavour and presentation of the product. The highest mean concentration of fluoride was found in the juices and cola drinks (0.67 +/- 0.38 and 0.49 +/- 0.41 p.p.m., respectively). The mean fluoride concentration for carbonated drinks was 0.43 +/- 0.36 p.p.m. Bottled waters had a fluoride concentration of 0.21 +/- 0.08 p.p.m.
Conclusions. The findings suggest that fluoride ingested through bottled drinks represents an important part of the total fluoride ingested by the population. In view of the wide variation of fluoride concentration in the tested products, it is necessary to implement regulatory guidelines for controlling its concentration in order to prevent dental fluorosis.

PMID: 15242382 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15195468

Food Addit Contam. 2004 Mar;21(3):210-5.

Total and acid-soluble fluoride content of infant cereals, beverages and biscuits from Brazil.

Buzalaf MA, de Almeida BS, Cardoso VE, Olympio KP, Furlani Tde A.

Department of Biological Sciences, Bauru Dental School, University of Sao Paulo, Sao Paulo, Brazil. mbuzalaf@fob.usp.br

Total fluoride (TF) and HCl 0.01 M ('gastric juice')-soluble fluoride (SF) were analysed in infant foods, beverages and calcium-rich biscuits. Samples were divided into seven categories: children cereals (A), chocolate-flavoured milk (B), soy beverages (C), filled biscuits (D), non-filled biscuits (E), wafer biscuits (F) and corn starch biscuits (G). Mean TF concentrations +/- SD (amplitude, unit microgram F ml-1 or microgram F g-1) were: (A) 4.25 +/- 3.04 (0.20-7.84, n = 6); (B) 0.34 +/- 0.47 (0.05-1.27, n = 6); (C) 0.15 +/- 0.07 (0.09-0.29, n = 8); (D) 8.44 +/- 1.76 (7.65-10.47, n = 4); (E) 12.41 +/- 1.15 (10.69-13.68, n = 4); (F) 0.35 +/- 0 (0.34-0.36, n = 4) and (G) 7.77 +/- 1.12 (6.86-8.68, n = 2). Five samples of cereals, one sample of chocolate-flavoured milk and 10 samples of biscuits were analysed for SF. In cereals analysed for SF, all fluoride was soluble, while for the chocolate-flavoured milk, approximately 50% of TF was soluble. Regarding the biscuits analysed for SF approximately 20% of TF was soluble. It was observed that some of the cereals and beverages, and most of the biscuits analysed, might be important contributors to total daily fluoride intake. When consumed just once per day, cereals and beverages might supply up to 25% of the maximum recommended daily fluoride intake (0.07 mg F kg-1 body weight) for a 2-year-old child (12 kg). For the filled, non-filled and corn starch biscuits, when 3, 32 or 20 units of them, respectively, are consumed just once per day, they may supply up to 16% of the maximum recommended daily fluoride intake. However, only approximately 25% of fluoride absorption occurs from the stomach and 75% from the small intestine. Therefore, a higher fluoride bioavailability is possible.

PMID: 15195468 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15189675

J Anal Toxicol. 2004 May-Jun;28(4):249-52.
 
Nail and bone surface as biomarkers for acute fluoride exposure in rats.

Afonso Rabelo Buzalaf M, Escolastico Caroselli E, Cardoso De Oliveira R, Mauro Granjeiro J, Whitford GM.

Departamento de Ciencias Biologicas, Faculdade de Odontologia de Bauru, Universidade de Sao Paulo, Alameda Octavio Pinheiro Brisolla 9-75, 17012-901, Bauru, SP, Brazil.

When acute exposure to fluoride is thought to be the cause of death, confirmation often depends on the analysis of some body fluid or tissue. The aim of this study was to evaluate the use of nails and the periosteal surface of bone as indicators of acute exposure to fluoride. Six groups of rats were given a single oral dose of fluoride (50 mg/kg body weight), while the control group was given deionized water. The rats were killed at 2, 4, 8, 16, 24, and 48 h after fluoride administration. Plasma and nails (the proximal halves) were collected and analyzed for fluoride with an ion-specific electrode after hexamethyldisiloxane-facilitated diffusion. A circular area of the femur (4.52 mm(2)) was etched with 0.5M HCl for 15 s, and, after the addition of a buffer, the solution was analyzed with an ion-specific electrode. Peak plasma concentration occurred at 2 h, followed by progressively declining concentrations. Peak nail fluoride concentrations occurred at 8 h. The mean nail concentrations at 8, 16, and 24 h were significantly higher than that of the control group. Bone surface concentrations were significantly higher than that of the control group at 4 h and thereafter. Thus, the proximal portion of nails and bone surface are suitable biomarkers for acute fluoride exposure in rats.

PMID: 15189675 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15228203

Community Dent Health. 2004 Jun;21(2):143-8.

Prevalence of fluorosis in children aged 6-9 years-old who participated in a milk fluoridation programme in Codegua, Chile.

Marino R, Villa A, Weitz A, Guerrero S.

School of Health, University of New England, Armidale, NSVW, Australia. rmarino@metz.une.edu.au

OBJECTIVE: To determine the prevalence and severity of enamel fluorosis in the permanent dentition of children aged 6-9 years old exposed to fluoride through a milk fluoridation programme in Codegua, Chile.
BASIC RESEARCH DESIGN: A survey was conducted in 2002 of a sample of school children living in Codegua (n = 215) and La Punta, the control community (n = 206) to compare enamel fluorosis data with those obtained in 1994. Dean's criteria were followed to assess enamel fluorosis.
RESULTS: It was found that 16.4% of the children aged 6-9 years from Codegua had questionable fluorosis in 2002, while in 1999 10.3% were classified in this category. In addition, 7.9% and 1.3% of the children in 2002 and 1994, respectively, had at least very mild fluorosis. These increments were not observed in the control community. Comparison of mean community fluorosis indices (CFI) between the children in 2002 (CFI = 0.18) and those in 1994 (CFI = 0.06) was found to be significant (p < 0.001). For La Punta, no statistically significant results were observed (CFI 0.16 vs. 0.15).
CONCLUSIONS: Present results indicate that, although there was an expected increase in the prevalence and severity of enamel fluorosis after four years of fluoride exposure, the CFI for Codegua in 2002 is well below the upper limit of the CFI range associated with a public health concern. Therefore, if the average daily fluoride ingestion was adjusted to more appropriate doses at the time of mineralisation of anterior permanent teeth, this would minimise the increase in the prevalence of enamel fluorosis without loosing the dental caries preventive effect of F.

PMID: 15228203 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15231293

Leg Med (Tokyo). 2004 Jul;6(3):197-200.
 
Fatality due to acute fluoride poisoning in the workplace.

Takase I, Kono K, Tamura A, Nishio H, Dote T, Suzuki K.

Department of Legal Medicine, Osaka Medical College, Osaka 569-8686, Japan.

We report a case of a 65-year-old worker who suffered a third-degree skin burn to 5% of his total body surface area as a result of being splashed in the face with hydrofluoric acid (HF). He died shortly thereafter without having received adequate first aid. His serum fluoride concentration was markedly increased at 6.38 mg/dl with hypocalcemia and hyperkalemia. We concluded that he died of HF poisoning. In this case he might have managed to avoid death if he had not been working alone and if he had received adequate first aid on the scene as soon as possible. We re-emphasize the need for the immediate initiation of first aid on the scene and the distribution of information on the risks of HF to workers.

PMID: 15231293 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15303400

Vet Hum Toxicol. 2004 Aug;46(4):216-8.

An improved method for emergent decontamination of ocular and dermal hydrofluoric acid splashes.

Soderberg K, Kuusinen P, Mathieu L, Hall AH.

Medical Service, Avesta Polarit, Torshalla, Sweden.

Accidental hydrofluoric acid (HF) splashes often occur in industrial settings. HF easily penetrates into tissues by initial acid action allowing fluoride ions to penetrate deeply, chelating calcium and magnesium. Resultant hypocalcemia and hypomagnesemia can be fatal. This report describes the utilization of Hexafluorine--a hypertonic, amphoteric, chelating decontamination solution--in workplaces where water decontamination followed by calcium gluconate inunction failed to prevent HF burns and systemic toxicity. Between 1998 and 1999, 16 cases of ocular and dermal HF splashes with either 70% HF or 6% HF/15% nitric acid (HNO3) were decontaminated with Hexafluorine at the worksite. HF burns did not develop and medical treatment other than initial decontamination was not reQuired in 12/16 (75%). In 7/16 (44%) cases, lost work time corresponded to duration of hospital observation (mean < 1 d).

PMID: 15303400 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15219444

J Colloid Interface Sci. 2004 Aug 1;276(1):159-66.
 
Interactions between variable-charge soils and acidic solutions containing fluoride: an investigation using repetitive extractions.

Zhu MX, Jiang X, Ji GL.

Department of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266003, People's Republic of China.

The reaction between two variable-charge soils and acidic solutions containing F was investigated with a repetitive extraction method. When added F concentration was 10(-4) mol/L, F did not markedly enhance solution pH in the whole prolonged extractions, in comparison with F-free acidic solution extractions. Most of the added F was adsorbed on soil surfaces and Al-F complexes were the dominant F species in solution. With increasing extractions, the fraction of Al-F slightly increased, arising from dissolution and/or desorption of Al. In comparison with F-free acidic solution extractions, F-induced Al dissolution did not significantly increase Al release, probably because of the modest reactivity of metal-F surface complexes at terminal sites at low F loading. The gradual decrease in Al release in the following extractions was due to the gradual depletion of readily reactive Al-containing mineral phases. In contrast to the low F loading, at an F concentration of 10(-3) mol/L, the pH was enhanced dramatically in the initial extraction and a high pH was maintained in the following extractions. In the initial extraction, the increase in negative surface charges and solution pH seemingly depressed proton-induced Al dissolution and enhanced readsorption of some positively charged Al-F complexes, resulting in low amounts of Al and F in solution. In the following several extractions, F-induced Al dissolution and desorption of Al-F complexes substantially enhanced the amounts of Al and F, and the fraction of Al-F complexes in solution. Several interconnected mechanisms such as ligand exchange, the release of OH(-) ions from soluble hydroxylated Al groups, desorption of Al as Al-F complexes, and F-induced breakdown of soil minerals were responsible for the alteration in pH, Al release, and the fraction of Al-F complexes in the later extractions. A molecular-level interpretation is needed in order to address the different impacts of varying F concentration levels on soil chemistry and environments.

PMID: 15219444 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15153698

Caries Res. 2004 May-Jun;38(3):258-62.
 
Systemic versus Topical Fluoride.

Hellwig E, Lennon AM.

Department of Operative Dentistry and Periodontology, Dental Clinic and Dental School, Albert Ludwigs University Freiburg, Freiburg, Germany. hellwig@zmk2.ukl.uni-freiburg.de

The actual mechanism of fluoride action is still a subject of debate. A dogma has existed for many decades, that fluoride has to be ingested and acts mainly pre-eruptively. However, recent studies concerning the systemic effect of fluoride supplementation concluded that the caries-preventive effect of fluoride is almost exclusively posteruptive. Moreover, epidemiologists have cast doubt on the validity of the 'old' studies dealing with fluoride use. The concept of the posteruptive fluoride effect is supported by in vitro and in situ investigations demonstrating that the mode of action of fluoride can be attributed mainly to its influence on de- and remineralization kinetics of dental hard tissues. Therefore, topical fluoride application (e.g. in the form of fluoridated dentifrices) should be encouraged. There are still important questions open that need to be answered despite existing knowledge about the caries-preventive effect of fluoride. Copyright 2004 S. Karger AG, Basel

PMID: 15153698 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15153687

Caries Res. 2004 May-Jun;38(3):182-91.
 
Changing paradigms in concepts on dental caries: consequences for oral health care.

Fejerskov O.

Royal Dental College, Faculty of Health Sciences, University of Aarhus, Aarhus, Denmark. of@dg.dk

Kuhn proposed in his Structure of Scientific Revolutions (1962) that the theoretical framework of a science (paradigm) determines how each generation of researchers construes a causal sequence.
Paradigm change is infrequent and revolutionary; thereafter previous knowledge and ideas become partially redundant. This paper discusses two paradigms central to cariology. The first concerns the most successful caries-preventive agent: fluoride. When it was thought that fluoride had to be present during tooth mineralisation to 'improve' the biological apatite and the 'caries resistance' of the teeth, systemic fluoride administration was necessary for maximum benefit. Caries reduction therefore had to be balanced against increasing dental fluorosis. The 'caries resistance' concept was shown to be erroneous 25 years ago, but the new paradigm is not yet fully adopted in public health dentistry, so we still await real breakthroughs in more effective use of fluorides for caries prevention. The second paradigm is that caries is a transmittable, infectious disease: even one caused by specific microorganisms. This paradigm would require caries prevention by vaccination, but there is evidence that caries is not a classical infectious disease. Rather it results from an ecological shift in the tooth-surface biofilm, leading to a mineral imbalance between plaque fluid and tooth and hence net loss of tooth mineral. Therefore, caries belongs to common 'complex' or 'multifactorial' diseases, such as cancer, cardiovascular diseases, diabetes, in which many genetic, environmental and behavioural risk factors interact. The paper emphasises how these paradigm changes raise new research questions which need to be addressed to make caries prevention and treatment more cost-effective. Copyright 2004 S. Karger AG, Basel

PMID: 15153687 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15151686

Community Dent Oral Epidemiol. 2004 Jun;32(3):166-72.

Determining the optimal concentration of fluoride in drinking water in Pakistan.

Khan AA, Whelton H, O'Mullane D.

Shaikh Zayed Federal Postgraduate Medical Institute, Shaikh Zayed Medical Complex, Lahore 54600, Pakistan. ayyazk@brain.net.pk

OBJECTIVES: This study was designed to determine the optimal concentrations of fluoride for drinking water in Pakistan. Clinical dental examination of 1020 school children aged 12 years was carried out in 19 cities of Pakistan. Correlation between concentrations of water fluoride, caries and fluorosis was investigated by analyzing the data on fluoride concentrations in drinking water in the sampled population for which the caries and the fluorosis levels were also measured.
METHODS: The optimal level of fluoride in drinking water is universally calculated by applying the equation of Galagan and Vermillion, which permits the calculation of water intake as a function of temperature. The annual mean maximum temperatures (AMMT) recorded during the last 5 years were collected from the meteorological centres of the 28 divisional headquarter stations. The average AMMT of Pakistan is 29 degrees C at which the optimal fluoride in drinking water of Pakistan was calculated to be 0.7 ppm. As drinking habits differ in various parts of the world, determination of optimal concentration of fluoride for drinking water in Pakistan was performed using a modified Galagan and Vermillion equation, which applies a correction factor of 0.56 to the equation. The optimal fluoride in drinking water in Pakistan using this modified equation was determined to be 0.39 ppm.
RESULTS: Observation of the correlation showed that a fluoride concentration of 0.35 ppm in drinking water was associated with maximum reduction in dental caries and a 10% prevalence of fluorosis.
CONCLUSIONS: Determining the most appropriate concentrations of fluoride in drinking water is crucial for communities. It is imperative that each country calculates its own optimal level of fluoride in drinking water based on the dose-response relationship of fluoride in drinking water with the levels of caries and fluorosis. Climatic conditions, dietary habits of the population and other possible fluoride exposures need to be considered in formulating these recommendations. Copyright Blackwell Munksgaard, 2004

PMID: 15151686 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15139951

Int J Paediatr Dent. 2004 May;14(3):167-74.

Fluoride, calcium and magnesium intake in children living in a high-fluoride area in Ethiopia. Intake through food.

Malde MK, Zerihun L, Julshamn K, Bjorvatn K.

University of Bergen, Department of Odontology, Arstadveien 17, N-5009 Bergen, Norway. marian.malde@nifes.no

OBJECTIVE: The aim of this study was to assess the daily dietary fluoride intake in children living in two neighbouring villages in the Wonji Shoa Sugar Estate, a rural part of the Ethiopian Rift Valley.
METHODS: The villages depended on water from different sources: Village A used either river water (Awash River, with 1.8 mg F(-)/L) or ground water (2.1 mg F(-)/L), while village K was served ground water with 14 mg F(-)/L. Fifteen fully weaned children below the age of 5 years were selected in each of the villages. Over a four-day period the total food intake for these children was assessed by using a duplicate portion technique. The food was analysed for fluoride by using a fluoride ion-selective electrode after the dry ashing. Furthermore, the energy of the food was measured, as well as the calcium and magnesium contents (atomic absorption spectrometry after microwave digestion with nitric acid and hydrogen peroxide). The mothers gave a description of the ingredients used for preparing the food. Relevant background information concerning food habits, etc. was collected through a food frequency questionnaire.
RESULTS: This study shows that considerable amounts of fluoride may be retained in food prepared on high-fluoride water. In village A, food contributed 2.3 mg F(-)/day, while a dietary fluoride intake of 4.8 mg/day was found in children in village K. Interestingly, the sevenfold higher fluoride concentration of the water used for food preparation in village K compared to village A, gave only a doubling in fluoride intake through food. Calcium intake was relatively low while magnesium intake was above the recommended level.
CONCLUSION: As the energy intake by both groups was low, some systematic underreporting might be suspected. Thus, the fluoride intake in the group may be even higher than what was actually found in this study.

PMID: 15139951 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15131626

Br Dent J. 2004 May 8;196(9):547-52; discussion 537.

Changes in water intake of Northumbrian adolescents 1980 to 2000.

Zohouri FV, Rugg-Gunn AJ, Fletcher ES, Hackett AF, Moynihan PJ, Mathers JC, Adamson AJ.

School of Dental Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4BW, UK.

OBJECTIVES: To determine: total water intake in young English adolescents; the relative importance of sources of water intake; and changes in water intake and sources of water between 1980 and 2000.
DESIGN: A cross-sectional observational study of the diets of 11-12-year-old children attending seven schools in south Northumberland, UK. The information obtained was compared with results from a similar survey carried out 20 years previously.
METHODS: All children attending these schools were invited to participate. They completed a three-day diet diary with an interview on the fourth day, on two occasions during the school year. Standard UK food composition tables were used and water intake from various sources calculated. Anthropometric and social class information was obtained.
RESULTS: Four hundred and twenty-four children completed all aspects of the study (64% of those eligible). The mean total water intake was 1,130 g d(-1), approximately the same as that recorded 20 years before. Water intake in relation to energy intake: water intake was 139 g MJ(-1) in boys and 143 g MJ(-1) in girls. Sixty-five per cent of water came from drinks and 35% from foods; very similar to proportions 20 years before. The sources of water in drinks had changed considerably, with a marked increase in consumption of soft drinks (especially carbonated drinks) and a decrease in consumption of hot drinks and milk. There were a few differences between sexes but little difference between social groups.
CONCLUSIONS: Total water intake was similar to that recorded 20 years previously and lower than intakes reported in other countries. Changes in the sources of water meant that less water consumed was likely to come from the tap in the house and more from drinks made elsewhere, than 20 years previously. These changes have implications for estimating fluoride intake in fluoridated areas.

PMID: 15131626 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15158376

J Colloid Interface Sci. 2004 Jul 1;275(1):35-9.
 
Adsorption of fluoride ions onto carbonaceous materials.

Abe I, Iwasaki S, Tokimoto T, Kawasaki N, Nakamura T, Tanada S.

Osaka Municipal Technical Research Institute, Morinomiya, Joto-ku, Osaka, Osaka 577-8514, Japan.

The characteristics of fluoride ion adsorption onto carbonaceous materials were derived as adsorption isotherms at different temperatures and in different pH solutions. The fluoride ion was adsorbed into pores in carbonaceous materials produced from wood; the larger the specific surface area, the more fluoride ions adsorbed. Bone char was the most effective adsorbent. The composition of bone char includes calcium phosphate, calcium carbonate, and so on. This suggests that the phosphate ion in bone char was exchanged with a fluoride ion. Moreover, the mechanism of fluoride ion adsorption onto bone char is clearly chemical in nature because the amount of fluoride ion adsorbed onto bone char increased with increasing temperature and decreasing pH. The amount of fluoride ion adsorbed onto bone char was also shown to depend on the concentration of sodium chloride in solution because of the "salting-out" effect. The adsorption of fluoride ion onto bone char is endothermic. Bone char can be utilized to remove fluoride ions from drinking water.

PMID: 15158376 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15173908

J Environ Monit. 2004 Jun;6(6):552-8. Epub 2004 Apr 02.

Simultaneous extraction of bromide, chloride, fluoride and sulfate from soils, waste- and building materials.

Buykx SE, Van Den Hoop MA, De Joode P.

National Institute of Public Health and the Environment, PO Box 1, 3720 BA Bilthoven, The Netherlands. magt.van.den.hoop@rivm.nl

The simultaneous extraction of bromide, chloride, fluoride and sulfate was studied in soils, waste- and building materials. Acid, neutral and alkaline extractants were used; 0.01 mol l(-1) H(3)PO(4), milliQ-water and 0.01 mol l(-1) NaOH, respectively. The extracts were analysed by ion chromatography and ion selective electrode. Extracted concentrations were compared with the amount obtained by an alkaline smelt, as an approximation of the total extractable content. The results indicate that there is a significant difference in extraction behaviour between waste- and building materials and soils. Bromide and chloride were in general completely extracted from the former solid materials, but less than 10% and 50%, respectively, from soils. Fluoride is strongly bound in all investigated samples; less than 10% of the total content was extracted with any of the three extractants. The fraction of extracted sulfate varied between 4 and 87% of the total content, and was in general larger in waste- and building materials than in soils. Differences in extracted concentration between the 3 extractants occurred mainly for fluoride and sulfate. Extracted bromide was similar with all three extractants and extracted chloride showed differences for the various soil samples only. Increasing the NaOH concentration up to 1 mol l(-1) resulted mainly in an increase of extracted amount of fluoride and for soils also in extracted amounts of bromide and sulfate. Although, the results show that the composition of the solid material strongly influences the final pH of the extract and the extracted amount of investigated anions, application of Milli-Q water as an extractant might be a very fruitful option within the development of the Dutch Building Materials Decree.

PMID: 15173908 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15211794

Wei Sheng Yan Jiu. 2004 May;33(3):288-91.

[Determination of fluorine in the environmental samples by combustion-hydrolysis-ion selective electrode method]

[Article in Chinese]

Feng F, Liu X, Yu J, Wang W.

Institute of Geographical Sciences and Nature Resources Research CAS, Beijing 100101, China.

OBJECTIVE: To establish a fast and accurately method of determination of fluorine in coal, hair and food by combustion-hydrolysis-ion selective electrode method.
METHODS: The influence factors on combustion-hydrolysis, such as silica weight, temperature and time of hydrolysis, sample weight and volume of distilled water were studied so that to determine the best of all testing conditions.
RESULTS: The time for hydrolysis in this method was reduced by one third of that of GB/T4633-1997 standard of PRC method. The fluorine in standard reference material such as tea, poplar leaves, coal and capsicum, and corn was determined on precision and accuracy by this method. The relative standard deviation was less than 5%. The recovery varied from 90.3% to 107.6%.
CONCLUSION: The method is suitable for determining fluorine in the various environmental samples.

PMID: 15211794 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15202259

Huan Jing Ke Xue. 2004 Mar;25(2):174-6.

[Study on the calcium-based sorbent for removal fluorine during coal combustion]

[Article in Chinese]

Li SL, Qi QJ, Liu JZ, Cao XY, Zhou JH, Cen KF.

College of Resource and Environment Engineering, Liaoning Technical University, Fuxin 123000, China.

In the paper, the reaction of CaO-HF and fluorine removal mechanics at high temperature by blending calcium-based sorbents with coal during coal combustion were discussed, and test results about fluorine retention during coal combustion in fluidized bed and chain-grate furnace were reported. The results identified that lime and calcium-based sorbets developed can restratin the emission of fluorine during coal combustion. The efficiency of fluorine removal can reach 66.7%-70.0% at Ca/F 60-70 by blending lime with coal in fluidized bed combustion, and the efficiency of fluorine removal are between 57.32% and 75.19% by blending calcium-based sorbets with coal in chain-grate furnace combustion. Blending CaO or lime with coal during coal combustion can remove SO2 and HF simultaneously.

PMID: 15202259 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15178259

J Colloid Interface Sci. 2004 Jul 15;275(2):355-9.
 
Use of oxide minerals to abate fluoride from water.

Mohapatra D, Mishra D, Mishra SP, Chaudhury GR, Das RP.

Regional Research Laboratory, Bhubaneswar 751013, India.

The removal of fluoride from aqueous solutions has been investigated using various oxide ores such as refractory grade bauxite, feed bauxite, manganese ore, and hydrated oxides of manganese ores (WAD). The refractory grade bauxite showed promising results. The studies were carried out as functions of contact time, pH, concentration of adsorbents, concentration of adsorbate, and temperature. The adsorption was rapid during the initial 5 min but equilibrium was attained within 120 min. The adsorption followed first-order kinetics. The present system followed the Langmuir adsorption isotherm model. Various thermodynamic parameters such as free energy, enthalpy, entropy, and equilibrium constants were calculated. The isosteric heat calculations showed that the adsorption process followed a heterogeneous model.

PMID: 15178259 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15167207

Eur J Cardiovasc Prev Rehabil. 2004 Feb;11(1):56-62.

Fluoride in the drinking water and the geographical variation of coronary heart disease in Finland.

Kaipio J, Nayha S, Valtonen V.

Department of Medicine, Division of Infectious Diseases, Helsinki University Central Hospital, Helsinki, Finland. juhana.kaipio@hus.fi

BACKGROUND: Fluoride in drinking water prevents dental disease, which in turn has been reported to increase the risk of coronary heart disease (CHD). Since mortality from CHD in Finland is high in the north-east where the fluoride content of drinking water is low, the association was examined here in more detail.
DESIGN: Mortality from CHD during the period 1961-1995 in 365 rural areas of Finland (188 888 deaths) was linked with 2131 drinking water fluoride determinations performed in 1958 using negative binomial regression, adjustments being made for sex, age, mean income of the resident commune and drinking water magnesium and calcium.
RESULTS: An inverse J-shaped relationship was found between drinking water fluoride and CHD, the association being most pronounced in the 1960s and levelling off consistently as a function of time. In 1961-1970, the adjusted mortality from CHD was 22% (95% confidence interval 18-27%) lower in the fourth quintile of fluoride (0.15-0.30 mg/l) than in the first quintile (0.00-0.06 mg/l) but this deficit reduced to 13% (7-18%) in 1991-1995.
CONCLUSIONS: Although causality cannot be asserted, the geographical pattern of CHD in Finland is consistent with the concentration of fluoride in drinking water. One mechanism could be that fluoride prevents dental infections, which in turn reduces mortality from CHD. The more widespread use of fluoridated toothpastes, soft drinks and certain food items since the 1960s may have reduced the significance of drinking water as a source of fluoride.

PMID: 15167207 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15269902

Environ Toxicol. 2004 Aug;19(4):318-28.
 
Physical and chemical aspects of long-term biodeterioration of some polymers and composites.

Lugauskas A, Prosychevas I, Levinskaite L, Jaskelevicius B.

Institute of Botany, Zaliuju ezeru 49, LT-2021 Vilnius, Lithuania.

A biodeterioration study was performed on synthetic polymeric materials including homogenous film made from poly(tetrafluorine ethylene), copolymer film made from tetrafluorine ethylene and perfluoromethyl vinyl ether, vulcanized rubber containing natural caoutchouc, and vulcanized rubber, the main component of which was synthetic butadiene nitrile caoutchouc. The materials were exposed for 12 years to the open air, in mycological containers, and in a cellar in maritime climate conditions: air humidity 72%-90% and seasonal average temperature of 17 degrees C in summer and -2.5 degrees C in winter. The studies of optical and electron microscopy revealed that microorganisms were able to develop not only on the surface of the materials but also to penetrate inside into deeper layers. The fungi that produced the most intensive deterioration in the fluorine polymers and vulcanized rubbers belonged to the Alternaria, Aspergillus, Aureobasidium, Cladosporium, Penicillium, Oidiodendron and Trichoderma genera. The fungi Aspergillus fumigatus, A. niger, Aureobasidium pullulans, and Trichoderma viride produced the most intensive deterioration in the fluorine films, whereas Alternaria tenuissima, Cladosporium herbarum, C. sphaerospermum, and fungi of the Oidiodendron genus were widespread on vulcanized rubbers. Fungi of the Aspergillus and Penicillium genera prevailed on both fluorine films and rubbers exposed in a cellar. Infrared spectroscopy indicated that the structures of poly(tetrafluorine ethylene) and the copolymer of tetrafluorine ethylene and perfluoromethyl vinyl ether did not change after the 12-year exposure; only insignificant changes in surface morphology were observed by optical microscopy. Vulcanized rubber made both from natural and from synthetic caoutchouc exposed for the same length of time showed rather evident changes in appearance and structure. X-ray graphical analysis revealed that new crystallization of the caoutchouc and a possible change in chemical composition of the fillers had occurred. Copyright 2004 Wiley Periodicals, Inc. Environ Toxicol 19: 318-328, 2004.

PMID: 15269902 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15293815

Aust Dent J. 2004 Jun;49(2):61-6.

An historical perspective on early progress of Queensland water fluoridation 1945-1954: sheep, climate and sugar.

Akers HF, Porter SA.

School of Dentistry, The University of Queensland. harry.akers@b130.aone.net.au

BACKGROUND: Queensland's virtual rejection of artificial water fluoridation sets it apart from other Australian states, yet the early fluoride environs has been scantily recorded.
METHODS: This paper used archives, literature review, personal interview and the traditional historic method.
RESULTS: The connection between Queensland artesian bore water and caries resistance was postulated as early as 1912. Four decades later, two Queensland-specific factors influenced the planning to fluoridate community water supplies. The first (1945-1950) was confusion between the high levels of fluoride in artesian water supplying the pastoral industry and the scientific concept of artificial water fluoridation of communal supplies. The second (1952-1954) involved further scientific investigation involving water consumption patterns, occupational dehydration and fluid homeostasis within a sub-tropical climate. The role of the Australian Dental Association Queensland Branch (ADAQ) in early fluoride politics was minimal. Four early protagonists are identified--two dentists, an engineer and the sugar industry.
CONCLUSIONS: Queensland had its advocates for artificial water fluoridation of communal supply as a means of caries prevention. Interest came from the dental, medical and engineering professions, and from the sugar industry. However, these efforts met with indifference based on confused extrapolation of the artesian experience (1945-1952) and hesitancy (1952-1954) due to contemporaneous concerns about human fluid homeostasis in Queensland's sub-tropical climate.

PMID: 15293815 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15122632

Chembiochem. 2004 May 3;5(5):614-621.

Organic Fluorine: Odd Man Out.

Dunitz JD.

Organic Chemistry Laboratory, Swiss Federal Institute of Technology, ETH-Honggerberg, 8053 Zurich,
Switzerland, Fax: (+41) 1-632-1109.

No Abstract

PMID: 15122632 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15122635

Chembiochem. 2004 May 3;5(5):637-643.

Fluorine in Medicinal Chemistry.

Bohm HJ, Banner D, Bendels S, Kansy M, Kuhn B, Muller K, Obst-Sander U, Stahl M.

Discovery Research, Pharmaceuticals Division, Roche, CH 4070 Basel, Switzerland, Fax: (+41) 61-6881745.

Fluorinated compounds are synthesized in pharmaceutical research on a routine basis and many marketed compounds contain fluorine. The present review summarizes some of the most frequently employed strategies for using fluorine substituents in medicinal chemistry. Quite often, fluorine is introduced to improve the metabolic stability by blocking metabolically labile sites. However, fluorine can also be used to modulate the physicochemical properties, such as lipophilicity or basicity. It may exert a substantial effect on the conformation of a molecule. Increasingly, fluorine is used to enhance the binding affinity to the target protein. Recent 3D-structure determinations of protein complexes with bound fluorinated ligands have led to an improved understanding of the nonbonding protein-ligand interactions that involve fluorine.

PMID: 15122635 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15122634

Chembiochem. 2004 May 3;5(5):628-635.

Use of Fluorine in the Medicinal Chemistry and Chemical Biology of Bioactive Compounds-A Case Study on Fluorinated Taxane Anticancer Agents.

Ojima I.

Institute of Chemical Biology and Drug Discovery and Department of Chemistry, State University of New York, Stony Brook, NY 11794-3400, USA, Fax: (+1) 631-632-7942.

No Abstract

PMID: 15122634 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15081716

Sci Total Environ. 2004 May 5;323(1-3):47-61. Related Articles, Links
 

Biomonitoring of the genotoxic potential (micronucleus assay) and detoxifying activity (EROD induction) in the River Dadou (France), using the amphibian Xenopus laevis.


Gauthier L, Tardy E, Mouchet F, Marty J.

Laboratoire d'Ecologie des Hydrosystemes-LEH, FRE CNRS UPS 2630, Centre Universitaire de formation et de Recherche Jean-Francois Champollion, campus d'Albi, place de Verdun, 81012 Albi Cedex 9, France.

Within the framework of a general survey of the water quality of the river Dadou (Tarn, France), different physico-chemical parameters were measured and an inventory of the fish population was made along the water course, around the Rassisse dam. With the aim of monitoring the potential genotoxic effects and the detoxifying activities induced in organisms exposed to the river water, two in vivo bioassays were performed in laboratory experiments, using larvae of the amphibian Xenopus laevis. The first was the micronucleus test, using red blood cells, and the second the assay of ethoxyresorufin-O-deethylase (EROD) induction in the liver of exposed animals. Eight water samples were taken from the river and at outlet points from the two major industrial activities of the studied section of the water course: a spar-fluor mine and a water treatment plant. Genotoxic impact and EROD induction were measured in the larvae. The effluent of the filter-washing process from the water treatment plant was found to be particularly genotoxic, even after dilution in pure reconstituted water, but no particular genotoxicity was found, either in Dadou river water, or in the effluents from the mine. On the other hand, most of the water samples tested produced a clear induction of EROD activity compared to the level of enzymatic activity found in the liver of larvae reared in the river water sampled upstream of the industrial activities. These results were interpreted taking into account
(i) the high concentrations of pollutants (fluorine and manganese) measured in the river water,
(ii) the very low population levels inventoried in the downstream section of the river and
(iii) the possible interactions between the substances present in the river water, particularly the classical EROD inducers PAHs and PCBs.

PMID: 15081716 [PubMed - in process]

See also

Food Chem Toxicol. 2003 Nov;41(11):1501-8.
Effects of fluoride on Xenopus embryo development.
Goh EH, Neff AW


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15122630

Chembiochem. 2004 May 3;5(5):570-589.

The Unique Role of Fluorine in the Design of Active Ingredients for Modern Crop Protection.

Jeschke P.

Bayer CropScience AG, BCS-R-GCI, Building 6240, Alfred-Nobel-Strasse 50, 40789 Monheim am Rhein, Germany, Fax: (+49) 214-30-46410.

The task of inventing and developing active ingredients with useful biological activities requires a search for novel chemical substructures. This process may trigger the discovery of whole classes of chemicals of potential commercial interest. Similar biological effects can often be achieved by completely different compounds. However, compounds within a given structural family may exhibit quite different biological activities depending on their interactions with different intracellular proteins like enzymes or receptors. By varying the functional groups and structural elements of a lead compound, its interaction with the active site of the target protein, as well as its physicochemical, pharmacokinetic, and dynamic properties can be improved. In this context, the introduction of fluorine into active ingredients has become an important concept in the quest for a modern crop protection product with optimal efficacy, environmental safety, user friendliness, and economic viability. Fluorinated organic compounds represent an important and growing family of commercial agrochemicals. A number of recently developed agrochemical candidates represent novel classes of chemical compounds with new modes of action; several of these compounds contain new fluorinated substituents. However, the complex structure-activity relationships associated with biologically active molecules mean that the introduction of fluorine can lead to either an increase or a decrease in the efficacy of a compound depending on its changed mode of action, physicochemical properties, target interaction, or metabolic susceptibility and transformation. Therefore, it is still difficult to predict the sites in a molecule at which fluorine substitution will result in optimal desired effects.

PMID: 15122630 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15122628

Chembiochem. 2004 May 3;5(5):559-562.

Editorial: Unveiling the Mystery and Beauty of Organic Fluorine.

[No authors listed]

No Abstract

PMID: 15122628 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15122631

Chembiochem. 2004 May 3;5(5):590-613.

The Influence of Fluorinated Molecules (Semiochemicals and Enzyme Substrate Analogues) on the Insect Communication System.

Pesenti C, Viani F.

Istituto di Chimica per il Riconoscimento Molecolare, Consiglio Nazionale delle Ricerche, Via Mancinelli 7, 20131 Milano, Italy, Fax: (+39) 02-2399-3080.

Can the introduction of fluorine atoms affect the bioactivity of natural semiochemicals? Can fluorine contribute in the creation of specific enzyme inhibitors to interrupt or disrupt the insect communication system? The first step for the bioactivity of a molecule is interaction with the biological sensor. Hydrogen and fluorine are almost bioisosteric and the receptor site of the enzyme can still recognize and accept the fluoro analogue of its natural substrate. However, the peculiar electronegativity of the fluorine atom can affect the binding, absorption, and transport of the molecule. The differences in the molecule's electronic properties can lead to differences in the chemical interactions between the receptor and the fluorinated substrate. Fluorine introduction can modify the metabolic stability and pathway of the semiochemicals in many different ways. Fluorinated analogues can show synergism, inhibition, or hyperagonism effects on insect behaviors, that is, the activity of the nonfluorinated parent compounds can be mimicked, lost, or increased. In any case, the fluorinated molecules can interact with the bioreceptors in a new and disrupting way. The semiochemicals are olfactory substances: fluorine can affect their volatility or smell. Production of semiochemicals from exogenous substances, perception at antennal receptors, and processing of biological responses are the main steps of communication among insects. In the production step, the fluorinated molecules can interact with enzymes that catalyze the biosynthesis of the natural pheromones. In the perception step, fluorinated semiochemicals can interact with the olfactory receptor cells; this often leads to totally unpredictable behaviors. Fluorinated molecules have been developed as probes to elucidate the complex chemorecognition processes of insects. Many of these molecules have been tested to find highly effective behavior-modifying chemicals. New analogues have been synthesized to investigate the metabolic pathway of a pheromone molecule and many of them are promising disrupting agents. Despite such titanic research efforts, the results have often been random, rational trends in the induced behaviors have sometimes been impossible to find, and practical applications of the fluorinated semiochemicals are still uncertain.

PMID: 15122631 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15042463

MAGMA. 2004 Mar 23 [Epub ahead of print]
 
Long-term sequestration of fluorinated compounds in tissues after fluvoxamine or fluoxetine treatment: a fluorine magnetic resonance spectroscopy study in vivo.

Bolo NR, Hode Y, Macher JP.

Magnetic Resonance Unit, FORENAP Research Center for Neuroscience Psychiatry, 27 rue du 4 RSM, F-68250, Rouffach, France.

Fluorine magnetic resonance spectroscopy ((19)F MRS), spectroscopic imaging (MRSI) and proton anatomical magnetic resonance imaging ((1)H MRI) were performed on brains and lower extremities of six subjects in vivo concurrently with HPLC of serum to investigate tissue and plasma drug localization and withdrawal kinetics in humans treated with fluvoxamine or fluoxetine. (19)F MRS signal was unexpectedly detected in the lower extremities months after complete disappearance of signal from plasma and brain. MRSI suggested that the lower extremity fluvoxamine signal originated mainly from bone marrow. Results suggest long-term sequestration of these drugs or their metabolites mainly in bone marrow and possibly in surrounding tissue and demonstrate the usefulness of MRS to reveal drug-trapping compartments in the body.

PMID: 15042463 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15057018

Dermatology. 2004;208(2):181.
 
Recurrent benign aphthous stomatitis and fluoride allergy.

Brun R.

Publication Types:
* Letter

PMID: 15057018 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15094549

Spine. 2004 Feb 15;29(4):E75-8.
 
Ossification of the transverse atlantal ligament associated with fluorosis: a report of two cases and review of the literature.

Wang W, Kong L, Zhao H, Jia Z.

Spinal Surgery Department, Tianjin Hospital, Tianjin City, People's Republic of China. wangwwb@yahoo.com.cn

STUDY DESIGN: Two cases of ossification of the transverse atlantal ligament (OTAL) are reported, and the literature is reviewed.
OBJECTIVE: To report two cases of OTAL, which share fluorosis as a possible etiologic link.
SUMMARY OF BACKGROUND DATA: OTAL, a rare phenomenon, may cause upper cervical canal stenosis and spastic quadriparesis. However, the incidence, etiology, and the best therapeutic options are currently unclear.
METHODS: Two cases are reported. Included are pertinent history, physical examination, radiographic evaluation, nonsurgical interventions, and outcomes. The available literature is also reviewed.
RESULTS: On systemic examination, these two cases were found to have ossification of many ligaments and interosseous membranes, i.e., the atlantal transverse ligament, posterior longitudinal ligament, and interosseous membranes of ribs, forearm, and leg. These findings were coupled with a history of high fluoride intake and dental fluorosis; the diagnosis of fluorosis was made. After 2 weeks of treatment with halo ring traction, and protection and stabilization with a hard cervical collar, the clinical symptoms significantly improved.
CONCLUSION: The incidence of OTAL may be not as rare as has been thought. Although the complete etiology of OTAL is not known, fluorosis may be one of the etiologic factors related to OTAL, as well as the ossification of other ligaments and interosseous membranes. Nonsurgical treatment may be safe and effective.

PMID: 15094549 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15114459

Bull Environ Contam Toxicol. 2004 Mar;72(3):579-85.
 
Effects of body size and sodium chloride on the tolerance of net-spinning caddisfly larvae to fluoride toxicity.

No abstract available

Camargo JA.

Department of Ecology, Faculty of Sciences, University of Alcala, 28871 Alcala de Henares, Madrid, Spain.

PMID: 15114459 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15107153

J Anal Toxicol. 2004 Apr;28(3):211-3.
 
A fatality due to ingestion of hydrofluoric acid.

Cordero SC, Goodhue WW, Splichal EM, Kalasinsky VF.

Armed Forces Institute of Pathology, Division of Environmental Toxicology, Washington, DC 20306-6000, USA.

We report a fatal case of hydrofluoric acid (HF) ingestion with suicidal intent. Quantitation using an ion-selective electrode for fluoride in fresh bile, gastric contents, kidney, liver, skeletal muscle, urine, and vitreous humor yielded 6.5, 39.0, 10.0, 6.0, 4.5, 5.0, and 4.5 ppm, respectively. In addition to the unfixed specimens, fluoride ion was measured in the following fixed tissue: brain, heart, kidney, liver, pancreas, stomach, and heart. Tissues were measured directly and/or by using the technique of standard addition. Fluoride concentrations using either method were found to be comparable. Fluoride concentration in fresh tissue was consistent with toxicity, although the urine fluoride concentration was in the range observed for asymptomatic workers exposed to fluoride in air. Fixed tissue preparations revealed fluoride concentrations consistent with nonexposure, whereas examination of the formalin fixative revealed fluoride concentrations only slightly higher than negative control formalin. We conclude that fixed tissues are inappropriate for fluoride determination. This is the first case we are aware of that provides fluoride concentrations in skeletal muscle in a fatality involving HF ingestion.

PMID: 15107153 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14987806

Environ Pollut. 2004 May;129(2):195-207.
 
Spatio-temporal behaviour and mass balance of fluorine in forest soils near an aluminium smelting plant: short- and long-term aspects.

Egli M, Durrenberger S, Fitze P.

Department of Geography, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland. megli@geo.unizch.ch

With the help of a large number of monitoring sites, the behaviour of F in forested ecosystems of a formerly polluted area (Mohlin and Rheinfelden, Switzerland) could be studied over 30 years. An aluminium smelting plant originated the pollution of this area in the past: however, after the installation of a filtration plant in 1958 the F emissions were reduced and since 1991 almost absent the primary production of aluminium was stopped. The present-day area with elevated F contents (water-soluble F with >20 mg/kg) is restricted to a radius of about 1000 m from the plant. In 1969 this area had a radius of about 3 and 5 km. Between 1969 and 2000 a significant decrease in the soluble F content in the soil was observed together with a substantial decrease of F in the vegetation. The net losses of water-soluble F in the soil were in the range of 35 up to more than 70% of the original concentration and the F losses in the vegetation between 60 up to more than 80%. After the reduction of high F deposition rates the accumulated SOM was decomposed within the observation period 1969-1993. The combined decrease in F and humus led to chain reactions with losses of major elements and a dealumination of clay minerals, i.e. removal of interlayered Al of 2:1 minerals and consequent formation of smectites.

PMID: 14987806 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15047676

J Am Coll Nutr. 2004 Apr;23(2):108-16.
 
Associations between Intakes of Fluoride from Beverages during Infancy and Dental Fluorosis of Primary Teeth.

Marshall TA, Levy SM, Warren JJ, Broffitt B, Eichenberger-Gilmore JM, Stumbo PJ.


Department of Preventive and Community Dentistry, University of Iowa College of Dentistry (T.A.M., S.M.L., J.J.W., B.B., J.M.E.-G.).

OBJECTIVE: We describe associations between primary tooth fluorosis status and intakes of beverages and fluoride from these beverages during infancy.
METHODS: Subjects (n = 677) are members of the Iowa Fluoride Study, a cohort of young children followed from birth. Food and nutrient intakes were obtained from 3-day diet records. Diets were analyzed at 6 weeks, 3, 6, 9, 12 and 16 months and cumulatively for 6 weeks through 16 months of age. Primary tooth fluorosis was assessed at 4.5-6.9 years of age and defined as present or absent. Multiple logistic regression analyses were used to develop models to predict fluorosis status.
RESULTS: Water-based beverage intakes were higher in subjects with fluorosis than in those without. Specifically, higher intakes of water used to reconstitute formulas at 3, 6 and 9 months; any intake of water as a beverage at 16 months; and higher intakes of combined 100% juice and miscellaneous beverages at 16 months were positively associated with fluorosis (p < 0.05). Fluoride intakes from water sources were also higher in subjects with fluorosis than in those without. Specifically, higher intakes of fluoride from water used to reconstitute formulas at 3, 6, 9 and 12 months and for 6 weeks through 16 months, and higher intakes of fluoride from water as a beverage at 16 months and for 6 weeks through 16 months were positively associated with fluorosis (p < 0.05).
CONCLUSION: Infant beverages, particularly infant formulas prepared with fluoridated water, can increase the risk of fluorosis in primary teeth.

PMID: 15047676 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15016119

Community Dent Oral Epidemiol. 2004 Apr;32 Suppl 1:62-8.

Urinary fluoride excretion by preschool children in six European countries.

Ketley CE, Cochran JA, Holbrook WP, Sanches L, Van Loveren C, Oila AM, O'Mullane DM.

Department of Clinical Dental Sciences, The University of Liverpool, Liverpool, UK.
Ketley CE, Cochran JA, Holbrook WP, Sanches L, van Loveren C, Oila A-M, O'Mullane DM.

Objective: To measure and compare 24-h urinary fluoride excretion in children aged 1.5-3.5 years from European study sites and to use these data to estimate the 24-h fluoride intake. Method: Twenty-four-hour urine samples were collected from 3-year-old children (n = 86) who were already participating in a European multicentre study. Samples were collected from Cork, Ireland (n = 19) where the water is fluoridated to a concentration between 0.8 and 1.0 ppm and from five sites with a water fluoride concentration <0.15 ppm: Knowsley, England (n = 18); Oulu, Finland (n = 18); Reykjavik, Iceland (n = 4); Haarlem, the Netherlands (n = 6); Almada/Setubal, Portugal (n = 21). The volume of the samples was measured; they were analysed for fluoride concentration and the 24-h urinary fluoride excretion was calculated. From this an estimate of the daily fluoride intake was made.
Results: It was found that the mean fluoride excretion in response to the usual conditions of fluoride intake in the children in the nonfluoridated areas ranged from 0.16 mg (+/-0.08) in Oulu to 0.33 mg (+/-0.27) in Almada/Setubal with an overall mean of 0.23 mg (+/-0.19). The mean 24-h fluoride excretion in fluoridated Cork was 0.37 mg (+/-0.11). There was a significant difference between the fluoride excretion in the nonfluoridated areas and that in the fluoridated areas, and the data were broadly in agreement with WHO standards. Conclusions: The daily urinary fluoride excretion and estimated fluoride intake in these children appeared to be within acceptable limits.

PMID: 15016119 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15016114

Community Dent Oral Epidemiol. 2004 Apr;32 Suppl 1:28-33.

A comparison of the prevalence of fluorosis in 8-year-old children from seven European study sites using a standardized methodology.

Cochran JA, Ketley CE, Arnadottir IB, Fernandes B, Koletsi-Kounari H, Oila AM, Van Loveren C, Whelton HP, O'Mullane DM.

The objectives of this study were to report on the prevalence of enamel opacities from seven European study sites using a standardized photographic method, and to investigate the importance of variables responsible for enamel fluorosis.
Methods: The sample comprised a randomly selected group of 300 8-year-old children in each of the study areas. One examiner from each area was trained and calibrated in the use of a standardized photographic technique. Two transparencies were taken of each child's permanent maxillary central incisor teeth; one to represent the teeth 'wet' and one when the teeth had been allowed to dry out naturally for 105 s. The transparencies were viewed 'blind' by the author (JAC) and scored using the DDE and TF indices. Data relating to variables considered to be associated with enamel fluorosis were also collected.
Results: The prevalence of diffuse opacities ranged from 61% in fluoridated Cork (Ireland) to 28% in Athens (Greece). The percentage of subjects with a TF score of three or more ranged from 4% in Cork and nonfluoridated Haarlem (the Netherlands) to zero in Oulu (Finland) and Athens. Fluoridated water and the prolonged use of fluoride tablets were found to be significant contributory factors to fluorosis.
Conclusions: The prevalence of fluorosis was found to be highest in fluoridated Cork. The prolonged use of fluoride supplements was also found to be a significant risk indicator associated with fluorosis.

PMID: 15016114 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15110059

Am J Prev Med. 2004 May;26(4):315-25.

Physicians' roles in preventing dental caries in preschool children; A summary of the evidence for the U.S. Preventive Services Task Force.

Bader JD, Rozier RG, Lohr KN, Frame PS.

Department of Operative Dentistry, School of Dentistry, and Cecil G. Sheps Center for Health Services Research, and, University of North Carolina at Chapel Hill (Bader) Chapel Hill, North Carolina, USA.

CONTEXT: Almost 20% of children aged 2 to 5 years have untreated dental caries. Physician interventions to prevent and manage dental caries in preschool children could help address this common problem. OBJECTIVE: To review the evidence for effectiveness of five possible physician interventions- (1) screening and risk assessment, (2) referral, (3) provision of dietary supplemental fluoride, (4) application of fluoride varnish, and (5) counseling-for the prevention of dental caries for the U.S. Preventive Services Task Force.
DATA SOURCES: Articles from 1966 to 2001 addressing the effectiveness of primary care clinicians' interventions to prevent or manage dental caries were identified in MEDLINE. The evidence for effectiveness of supplemental fluorides, fluoride varnish, and counseling for caries prevention performed by dental personnel was also examined through existing and new systematic reviews.
DATA SYNTHESIS: For most key questions related to the five interventions, the evidence for primary care clinician effectiveness was rated as poor owing to the scarcity of studies. Ten surveys of physicians' knowledge and behavior about fluoride supplementation provided fair evidence, suggesting that supplementation decisions were often made without consideration of other fluoride exposures. Reviews of the dental literature identified fair evidence supporting the effectiveness of both fluoride supplements and varnish, although information describing effectiveness and adverse outcomes of supplementation with the most recent dosage schedule is not available.
CONCLUSIONS: Evidence for the effectiveness of traditionally recommended primary care clinician interventions (screening, referral, counseling) to prevent dental caries in preschool children is lacking. There is fair evidence for the effectiveness of two fluoride-based interventions (fluoride supplementation and varnish) applicable in primary care practice. However, there is also fair evidence indicating that physicians' consideration of fluoride exposure is incomplete, thus increasing the risk for fluorosis among those prescribed supplements.

PMID: 15110059 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15108377

Vestn Ross Akad Med Nauk. 2004;(3):46.

[In Process Citation]

[Article in Russian]

[No authors listed]

Negative pollution effects from atmospheric discharges by aluminium facilities exerted on population health can be traced by the parameters of the reproductive function in women, physical development of newborns, general and differential morbidity of children aged below one year as well as by anthropometric signs in birth, morbidity of children and adults, mortality, including due to oncology. The introduction of modern technologies including the preliminarily fire anode treatment and the use of highly effective methods of purification of industrial wastes cut the concentration (in atmospheric air) of anhydrous hydrogen fluoride and of solid fluorides as well as of aluminium to maximum permissible concentration; it also essentially reduced the content of benzapilene. A better atmospheric air observed yet in the course of renovation contributed to a lower morbidity of children, aged below one year, as well as to the prevalence of diseases affecting the eyes, respiratory and digestive organs, skin and subcutaneous cellular tissue; it also cuts the number of congenital anomalies versus the data obtained in a neighboring district.

PMID: 15108377 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14987806

Environ Pollut. 2004 May;129(2):195-207.
 
Spatio-temporal behaviour and mass balance of fluorine in forest soils near an aluminium smelting plant: short- and long-term aspects.

Egli M, Durrenberger S, Fitze P.

Department of Geography, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland. megli@geo.unizch.ch

With the help of a large number of monitoring sites, the behaviour of F in forested ecosystems of a formerly polluted area (Mohlin and Rheinfelden, Switzerland) could be studied over 30 years. An aluminium smelting plant originated the pollution of this area in the past: however, after the installation of a filtration plant in 1958 the F emissions were reduced and since 1991 almost absent the primary production of aluminium was stopped. The present-day area with elevated F contents (water-soluble F with >20 mg/kg) is restricted to a radius of about 1000 m from the plant. In 1969 this area had a radius of about 3 and 5 km. Between 1969 and 2000 a significant decrease in the soluble F content in the soil was observed together with a substantial decrease of F in the vegetation. The net losses of water-soluble F in the soil were in the range of 35 up to more than 70% of the original concentration and the F losses in the vegetation between 60 up to more than 80%. After the reduction of high F deposition rates the accumulated SOM was decomposed within the observation period 1969-1993. The combined decrease in F and humus led to chain reactions with losses of major elements and a dealumination of clay minerals, i.e. removal of interlayered Al of 2:1 minerals and consequent formation of smectites.

PMID: 14987806 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15115378

J Air Waste Manag Assoc. 2004 Apr;54(4):495-503.

A risk-based model to establish threshold planning quantities of hazardous substances.

Mohan M, Gurjar BR.

Centre for Atmospheric Sciences, Indian Institute of Technology, Hauz Khas, New Delhi, India. mmanju@cas.iitd.ernet.in

The Threshold Planning Quantity (TPQ) is the minimum quantity of any hazardous substance stored or processed at an industry that can pose a defined level of risk up to a certain distance from the industrial premises should an accidental release occur. These are recommended by the concerned government departments of the respective countries. Often, concerned regulatory authorities focus on simple screening tools to prescribe TPQs of hazardous chemicals rather than on more detailed technical aspects. This is illustrated with the help of TPQs presently administered in India, which are followed based on Control of Industrial Major Accident Hazard regulations of the United Kingdom. In this paper, the risk ranking matrix (RRM) approach is described to evaluate the recommended TPQs and prescribe these for some extremely hazardous chemicals (EHS) commonly used in industries. The RRM presented here is unique in the sense that various acceptable risk criteria are reviewed to appropriately rank the risk potential and provide suitability criteria in terms of individual risk factors and geosocietal risk factors (GSRF). Based on this concept, an attempt has been made to develop a risk-based model to determine the TPQs of various EHS (acrolein, ammonia, chlorine, hydrogen fluoride, and phosgene).

PMID: 15115378 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15095895

Environ Toxicol Chem. 2004 Apr;23(4):982-9.

Elk exposure to arsenic in geothermal watersheds of Yellowstone National Park, USA.

Kocar BD, Garrott RA, Inskeep WP.

Department of Geological and Environmental Sciences, Stanford University, Palo Alto, California 94305, USA.

Geothermal activity in Yellowstone National Park (WY, USA) (YNP) results in elevated levels of arsenic in surface waters, aquatic vegetation, and sediments in the Upper Madison River Basin. This study was conducted to determine concentrations of arsenic in the tissues, feces, and rumen contents of elk (Cervus elaphus) residing in the Madison-Firehole (MF) River basin, and to evaluate potential arsenic exposure pathways. Concentrations of total arsenic in MF elk were significantly higher than in control elk populations, and analysis of arsenic in surface waters, elk forage, sediments, and soils suggests that the predominant arsenic exposure pathways are forage species found in aquatic and riparian habitats. Analysis of arsenic species in selected plant and elk samples indicated that the ingested forms of arsenic are predominantly inorganic, while the appearance of dimethylarsonate in elk rumen and feces suggests that arsenic is subject to methylation reactions after ingestion, potentially contributing to arsenic detoxification. Arsenic:creatinine ratios of elk urine samples analyzed across three different winters increased during winter progression and were correlated with total snow water equivalent as an index of winter severity. Exposure to arsenic and other trace elements (fluorine) may contribute to the previously observed decreased life expectancy of MF elk relative to control populations.

PMID: 15095895 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15083934

J Toxicol Clin Toxicol. 2004;42(1):33-40.

A simple, safe, and efficient way to treat severe fluoride poisoning--oral calcium or magnesium.

Kao WF, Deng JF, Chiang SC, Heard K, Yen DH, Lu MC, Kuo BI, Kuo CC, Liu TY, Lee CH.

Department of Emergency Medicine, Veterans General Hospital, Taipei, Taiwan, ROC. wfkao@vghtpe.gov.tw

PURPOSE: To examine the efficacy and safety of administration of calcium and magnesium orally and intraperitoneally to treat severe sodium fluoride intoxication.
MATERIALS AND METHODS: Mice were initially gavaged a lethal dose of sodium fluoride (NaF) or water. Then, mice were treated with water or varying concentrations of calcium chloride (CaCl2) or magnesium sulfate (MgSO4) via intraperitoneal (IP) route or via oral route. Mice were monitored for 24 h, and the time of death was recorded.
RESULTS: IP injections of large amounts of CaCl2 or MgSO4 were dangerous. All mice gavaged with water and then treated with oral CaCl2 or MgSO4 survived and displayed normal activity during the experiment. The survival rate of mice gavaged with a lethal dose of NaF and then treated with a high dose of oral CaCl2 or MgSO4 was significantly higher than those of using low dose.
CONCLUSION: Oral administration of a high dose of CaCl2 or MgSO4 is a simple, safe, and effective adjunctive method for treating severe oral fluoride poisoning.

PMID: 15083934 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15005697

Int J Paediatr Dent. 2004 Mar;14(2):94-100.

Dental caries experience in children with congenital heart disease: a case-control study.

Stecksen-Blicks C, Rydberg A, Nyman L, Asplund S, Svanberg C.

Pediatric Dentistry, Faculty of Medicine and Odontology, Umea University, S-901 85 Umea, Sweden. christina.stecksen@vll.se

OBJECTIVES: To compare the dental health of a group of children with complex congenital heart disease with that of age and gender matched healthy controls.
DESIGN: Case-control study.
SETTING: Faculty of Medicine and Odontology/Pediatric cardiology and Pedodontics, Umea University, Sweden.
SAMPLE AND METHODS: All the cases and their controls lived in the county of Vasterbotten in northern Sweden. Each group comprised 41 children with a mean age of 6.5 years. Data were collected from medical and dental records while all bitewing radiographs were read separately by one of the authors.
RESULTS: Children with congenital heart disease had significantly more caries in their primary teeth than the control group. The mean dmfs-value was 5.2 +/- 7.0 in the cardiac group compared to 2.2 +/- 3.5 in the control group (P < 0.05). Twenty-six of the children had all four 6-year-molars, and their mean DMFS-values were 0.9 +/- 1.9 in the cardiac group compared to 0.3 +/- 0.6 in the control group (P > 0.05). The children with congenital heart disease had received more caries prevention based on the use of fluorides than the control group. There was a significant correlation between the number of fluoride varnish treatments and the dmfs value of the child (r = 0.411, P < 0.01). Fifty-two per cent of the children in the cardiac group had been prescribed fluoride tablets on one or more occasions compared to 17% in the control group (P < 0.01). Number of months on digoxin medication and the dmfs-value had a significant correlation (r = 0.368, P < 0.05). Ten of the children had been on digoxin medication between 6 and 87 months; this subgroup had a mean dmfs-value of 10.1 +/- 8.5.
CONCLUSION: Swedish children with complex congenital heart disease have poorer dental health than healthy age and gender matched controls in spite of intensive preventive efforts. In many cases, intervention had been given when caries were present. A closer cooperation between paediatric cardiology and paediatric dentistry is needed.

PMID: 15005697 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15061890

Zhonghua Kou Qiang Yi Xue Za Zhi. 2004 Mar;39(2):139-41.

[Effect of drinking water change upon the dental fluorosis]

[Article in Chinese]

Ruan JP, Liu ZQ, Song JL, Bjorvatn K, Ruan MS.

Department of Dental Public Health, Dental School of Xi'an Jiaotong University, Xi'an 710004, China. Email: jianping_ruan@hotmail.com

OBJECTIVE: To assess changes in prevalence and degree of dental fluorosis in individuals born before and after the introduction of water with 1.2 mg/L fluoride instead of water with 2.0 - 10.0 mg/L fluoride previously used in Da Li County in China.
METHODS: The students (n = 291) were divided into 2 groups. Thedental fluorosis was scored according to Dean's classification. The statistical analysis was performed by t-test and chi(2) tests.
RESULTS: The prevalence of dental fluorosis was significantly lower in the group of the students drinking water from the new well (group 1) as compared to the group of the students drinking the old water (group 2), i.e. 48.8% versus 87.2% (P < 0.01). The percentage of moderate to very severe fluorosis was 13.9% and 0 in group 1 as compared to 32.0% and 8.8% in group 2. The fluorosis community index (FCI), defined by Dean, in group1 and 2 was medium (1.01) and marked (2.12) respectively.
CONCLUSIONS: The results showed that:
(1) The prevalence of dental fluorosis was significantly lowered by the new source of drinking water.
(2) Drinking water, even with 1.2 mg/L fluoride, may cause dental fluorosis during the period of tooth mineralization.

PMID: 15061890 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15080365

Pediatr Dent. 2004 Jan-Feb;26(1):87-92.

Tooth-brushing and dentifrice use among children ages 6 to 60 months.

Franzman MR, Levy SM, Warren JJ, Broffitt B.

Department of Preventive and Community Dentistry, The University of Iowa College of Dentistry, Iowa City, Iowa, USA.

PURPOSE: Tooth-brushing and fluoride dentifrice use are the primary oral health activities for young children. Fluoridated dentifrice has had an important impact on the reduction in children's caries lesion rates, but no studies have focused on patterns of use at multiple time points early in life. The purpose of this paper is to describe tooth-brushing and fluoride dentifrice use in a cohort of children from ages 6 to 60 months.
METHODS: The data are from the Iowa Fluoride Study, a longitudinal investigation of fluoride intake from birth. Questionnaires assessed tooth-brushing patterns and fluoride dentifrice use at age 6 months, and at 3-, 4-, or 6-month intervals thereafter.
RESULTS: At 6 months of age, 28% of the children's teeth were brushed or cleaned, and 3% of these used fluoridated dentifrice, increasing to 95% at 20 months (83% of them with fluoridated dentifrice). Use of dentifrice flavored for children increased from 40% of those brushing at 9 months to 71% at 60 months. From 9 to 32 months, about 55% of the children were using approximately the recommended amount of dentifrice. However, the percentage using more than recommended increased from 12% at 9 months to 64% at 60 months. Mothers placed the dentifrice on the toothbrush 85% of the time at 9 months, 81% at 20 months, 49% at 36 months, and 31% at 60 months.
CONCLUSIONS: By age 2, almost all children were brushing with fluoridated dentifrice, but less than half brushed twice a day, even at age 5. Mothers played the most important role in the children's home care habits.

PMID: 15080365 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15078061

J Public Health Dent. 2004 Winter;64(1):45-9.

Problems in exposure assessment of fluoride in drinking water.

Bassin EB, Mittleman MA, Wypij D, Joshipura K, Douglass CW.

Department of Oral Health Policy and Epidemiology, Harvard School of Dental Medicine, USA.

OBJECTIVES: We developed a source documentation approach that identified fluoride content of drinking water at the state or local level to estimate fluoride concentrations from public water systems. We then compared estimates from this approach with estimates obtained from a single source, the 1992 Centers for Disease Control and Prevention (CDC) Fluoridation Census.
METHODS: We used residential histories from a case-control study. For each residence we attempted to determine fluoride concentrations using the 1992 CDC Fluoridation Census. For the source documentation method we utilized multiple sources from state and local contacts to verify and collect additional data. We compared the fluoride estimates obtained by the two methods.
RESULTS: When fluoride values were found using both methods, there was good correlation (Kendall's tau = 0.85; 95% confidence interval = 0.79, 0.90) and concordance was 96 percent. We obtained over 99 percent of the fluoride values needed using source documentation as compared to 49 percent of the values needed when we used a single publication. When fluoride values were missing using the 1992 CDC Fluoridation Census, 21 percent had source documentation estimates of at least 0.7 ppm.
CONCLUSIONS: Researchers need to consider limitations of using a secondary data source to estimate fluoride in drinking water, particularly in studies where exposure to fluoride is the primary exposure of interest.

PMID: 15078061 [PubMed - in process]


Link to full free report (in Portugese) available at:
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15073621

Cad Saude Publica. 2004 Mar-Apr;20(2):422-9. Epub 2004 Apr 06.
 
[Twenty-four months of external control of fluoride levels in the public water supply in Pelotas, Rio Grande do Sul, Brazil]

[Article in Portuguese]

Lima FG, Lund RG, Justino LM, Demarco FF, Del Pino FA, Ferreira R.

Faculdade de Odontologia, Universidade Federal de Pelotas, Pelotas, Brasil.

The aim of the present study was monthly evaluation of fluoride levels in the public water supply in Pelotas, Rio Grande do Sul State, Brazil, and the validity of forming external control groups. Pelotas was divided into 16 geographic regions, including the three public water treatment stations. Water samples were collected from November 1999 to October 2001. Two samples were drawn from each region. Samples were sent to the Fluoride Health Surveillance Laboratory at Universidade do Vale do Itajai. Fluoride analysis used an electrometric method (Orion 920 A/Electrometer Orion 9609). After 24 months, 764 samples were collected, demonstrating a discontinuity in the fluoride levels. There was an increase in the number of samples with an ideal concentration of fluoride. However, several points with excessive fluoride levels (> 0.9ppmF) also appeared. Based on these results it was concluded that external control is essential for monitoring fluoride levels in the public water supply.

PMID: 15073621 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15060898

Int J Vitam Nutr Res. 2004 Jan;74(1):27-34.

Use of vitamin D and other dietary supplements by Finnish children at the age of 2 and 3 years.

Marjamaki L, Rasanen M, Uusitalo L, Ahonen S, Veijola R, Knip M, Virtanen SM.

Tampere School of Public Health, 33014 University of Tampere, Finland. liisa.marjamaki@satshp.fi

The aims of this study were to investigate the frequency of the use of vitamin D and other dietary supplements by Finnish children at the age of 2 and 3 years, to evaluate daily nutrient intake from supplements, and to investigate the relation between supplement use and various sociodemographic factors. The families of 534 newborn infants were invited to a birth cohort study in 1996-1997. Families of 292 children at the child's age of 2 years and families of 263 children at the age of 3 years completed a three-day food record from which the daily use of dietary supplements was calculated. The frequency of dietary supplement use was 50% among the two-year-olds, and 37% among the three-year-old children. The most commonly used supplements among the two-year-olds were vitamin D or vitamin A + D combination (38%) and fluoride (16%) and among the three-year-olds fluoride (19%) and multivitamins (16%), respectively. Intake of nutrients other than vitamin D or fluoride from supplements was rare among two-year-olds, whereas 16% of the three-year-olds received also vitamin A, C, E, and several group B vitamins. Mean daily intake of vitamin D from supplements was 6.7 micrograms at the age of 2 years and 5.3 micrograms at the age of 3 years, respectively. The level of parental education was positively associated with the child's vitamin D supplementation at the age of 2 years. As the compliance with national recommendations of vitamin D supplementation was low, intensified counseling of the parents is needed at the well-baby clinics in Finland.

PMID: 15060898 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14765200

Nature. 2004 Feb 5;427(6974):561-5.
 
Crystal structure and mechanism of a bacterial fluorinating enzyme.

Dong C, Huang F, Deng H, Schaffrath C, Spencer JB, O'Hagan D, Naismith JH.

Centre for Biomolecular Sciences, The University of St Andrews, Fife KY16 9ST, UK.

Fluorine is the thirteenth most abundant element in the earth's crust, but fluoride concentrations in surface water are low and fluorinated metabolites are extremely rare. The fluoride ion is a potent nucleophile in its desolvated state, but is tightly hydrated in water and effectively inert. Low availability and a lack of chemical reactivity have largely excluded fluoride from biochemistry: in particular, fluorine's high redox potential precludes the haloperoxidase-type mechanism used in the metabolic incorporation of chloride and bromide ions. But fluorinated chemicals are growing in industrial importance, with applications in pharmaceuticals, agrochemicals and materials products. Reactive fluorination reagents requiring specialist process technologies are needed in industry and, although biological catalysts for these processes are highly sought after, only one enzyme that can convert fluoride to organic fluorine has been described. Streptomyces cattleya can form carbon-fluorine bonds and must therefore have evolved an enzyme able to overcome the chemical challenges of using aqueous fluoride. Here we report the sequence and three-dimensional structure of the first native fluorination enzyme, 5'-fluoro-5'-deoxyadenosine synthase, from this organism. Both substrate and products have been observed bound to the enzyme, enabling us to propose a nucleophilic substitution mechanism for this biological fluorination reaction.

PMID: 14765200 [PubMed - indexed for MEDLINE]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15024934

Orv Hetil. 2004 Feb 1;145(5):229-32.
[In Process Citation]
[Article in Hungarian]
Albrecht M, Maros E.

Semmelweis Egyetem, Fogorvostudomanyi Kar, Konzervalo Fogaszati Klinika, Budapest.

Extensive experimental ad clinical data have established that in a concentration of approximately 1 mg/L in drinking water fluoride is highly effective in reducing the incidence of dental caries and dental plaque. However because of its well established cariostatic property, fluoride is being added to dental care and dental health product. In Hungary, community water fluoridation has not occurred, and the fluoride concentration of the drinking water is generally minimal. 95% of the population live in areas of the country where the majority of the population ingests water containing fluoride at a concentration of less than 0.5 mg/L. There are, however, communities in which the natural fluoride concentration in the drinking water is 1.7 or 2.0 mg/L. These are Bar ad Dunaszekcso. This study is designed to evaluate both prevalence and intensity of dental fluorosis, oral hygiene and periodontal diseases in the children in communities with suboptimal, 1.7x and 2x optimal fluoride concentration of drinking water.
MATERIAL AND METHODS: 141 healthy school-children in the 6-18 age groups who were lifetime residents in the communities Bar and Dunaszekcso, and 140 from Budapest have been asked to participate in this cross-sectional study. The examinations were performed using; the Fluorosis Index of Dean and the Tooth Surface Index of Fluorosis of Horowitz et al. The prevalence and intensity of gingivitis and oral hygiene were determined by the Russell (PI)-index and the Greene Vermillion Oral Hygiene index (OHI-S).
RESULTS:
1. The prevalence and intensity of gingivitis and oral hygiene were changing with fluoride concentration in the water supply.
2. On the basis of the number and distribution of the individual scores a community index of dental fluorosis (Fd) were in both community above 0.6, therefore it begins to constitute a public health problem warranting increasing consideration.
3. The intensity of the fluorosis was changed with aging (p < 0.001). This was tested by comparing the fluorosis scores in 6-13 year old children, with the scores for those who were 14-18 years of age.
4. There were no differences in the oral hygiene status and in the intensity of gingivitis between children living in a high-fluoride city and those living in a low-fluoride city.
CONCLUSION: The study supports the need of continuous monitoring of the prevalence of dental fluorosis in school-age children. Concerning the reduction in gingivitis and the oral hygiene status the authors found no differences between children living in a high-fluoride or in a low fluoride city.


PMID: 15024934 [PubMed - in process]


Full free report available at
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-89102004000100014&lng=en&nrm=iso

Rev Saude Publica. 2004 Feb;38(1):100-5. Epub 2004 Jan 30.
 
Fluoride and aluminum in teas and tea-based beverages.

Hayacibara MF, Queiroz CS, Tabchoury CP, Cury JA.

Departamento de Ci ncias Fisiol gicas, Faculdade de Odontologia de Piracicaba, Universidade Estadual de Campinas, Piracicaba, SP, Brasil.

OBJECTIVE: To evaluate fluoride and aluminum concentration in herbal, black, ready-to-drink, and imported teas available in Brazil considering the risks fluoride and aluminum pose to oral and general health, respectively.
METHODS: One-hundred and seventy-seven samples of herbal and black tea, 11 types of imported tea and 21 samples of ready-to-drink tea were divided into four groups: I-herbal tea; II-Brazilian black tea (Camellia sinensis); III-imported tea (Camellia sinensis); IV-ready-to-drink tea-based beverages. Fluoride and aluminum were analyzed using ion-selective electrode and atomic absorption, respectively.
RESULTS: Fluoride and aluminum levels in herbal teas were very low, but high amounts were found in black and ready-to-drink teas. Aluminum found in all samples analyzed can be considered safe to general health. However, considering 0.07 mg F/kg/day as the upper limit of fluoride intake with regard to undesirable dental fluorosis, some teas exceed the daily intake limit for children.
CONCLUSIONS: Brazilian and imported teas made from Camellia sinensis as well as some tea-based beverages are sources of significant amounts of fluoride, and their intake may increase the risk of developing dental fluorosis.

PMID: 14963548 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14768861&dopt=Abstract

Environ Toxicol Chem. 2004 Jan;23(1):12-6.

Source of toxicity in storm water: zinc from commonly used paint.

Kszos LA, Morris GW, Konetsky BK.

Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6422, USA. kszosla@ornl.gov

A Department of Energy site in Paducah, Kentucky (USA), stores thousands of cylinders of depleted uranium hexafluoride. Breaches of the cylinders could result in the release of uranium and hydrogen fluoride. Beginning in 1996, a program was begun to paint the cylinders in order to prevent corrosion of the cylinders and the surfaces of the storage yards were converted to concrete. In 1998, storm water from the cylinder storage yards was found to be toxic to Ceriodaphnia, at concentrations exceeding limits in the site's discharge permit. A six-month study was conducted to identify the source of the toxicity in the storm water. Ceriodaphnia toxicity tests with the storm water resulted in 48-h median lethal concentrations (LC50) ranging from 12 to 94%; zinc concentrations in the storm water ranged from 0.08 to 0.54 mg/L. Acute toxicity tests with zinc and linear regression identified that zinc concentrations in the storm water were sufficient to account for the toxicity observed. By tracking the sources to the discharge point, newly painted cylinders were identified as the source of the zinc in the storm water. Rainwater collected directly from the painted cylinders contained up to 13 mg Zn/L. Laboratory and field tests showed that topcoating the cylinders would reduce the amount of zinc in the runoff from the cylinders.

PMID: 14768861 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14757021&dopt=Abstract

An Pediatr (Barc). 2004 Feb;60(2):161-9. Related Articles, Links
 
[Drinking water in infants]

[Article in Spanish]

Vitoria Minana I.

Seccion de Nutricion Infantil. Hospital Lluis Alcanyis. Xativa. Valencia. Profesor Asociado de Nutricion y Bromatologia. Universidad de Valencia. Espana.

We review types of public drinking water and bottled water and provide recommendations on the composition of water for infants. Water used with any of the commercial infant formulas in Spain should contain less than 25 mg/l of sodium. Drinking water must be boiled for a maximum of one minute (at sea level) to avoid excessive salt concentration. Bottled water need not be boiled. Fluoride content in drinking water should be less than 0.3 mg/l in first year of life to prevent dental fluorosis. Nitrate content in water should be less than 25 mg/l to prevent methemoglobinemia. Water with a calcium concentration of between 50 and 100 mg/l is a dietary source of calcium since it provides 24-56 % of the required daily intake in infancy.

PMID: 14757021 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14691118&dopt=Abstract

J Dent Res. 2004 Jan;83(1):76-80.
 
Is fluoride concentration in dentin and enamel a good indicator of dental fluorosis?

Vieira AP, Hancock R, Limeback H, Maia R, Grynpas MD.

Faculty of Dentistry, University of Toronto.

Despite some studies correlating dental fluorosis (DF) and fluoride (F) concentration in dental enamel, no information is available about DF and dentin F concentration. Our objective was to determine the correlation between teeth F concentration and DF severity in unerupted human 3rd molars, and the correlation between dentin and enamel F concentrations in the same tooth. Ninety-nine 3rd molars were studied-53 from Fortaleza, Brazil (F water, 0.7 ppm), 22 from Toronto (1.0 ppm), and 24 from Montreal (0.2 ppm). DF severity was evaluated according to the Thylstrup-Fejerskov Index, while F concentration was analyzed by Instrumental Neutron Activation Analysis. DF severity varied between TF0 and TF4, while F concentration ranged between 39 and 550 ppm in enamel and 101 and 860 ppm in dentin. Our results showed correlation between dentin F concentration and DF (r(S) = 0.316, p = 0.001), but no correlation between enamel F concentration and DF (r(S) = 0.154, p = 0.133). No correlation was observed between dentin and enamel F concentrations in the same tooth (r(S) = 0.064, p = 0.536).

PMID: 14691118 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14693439&dopt=Abstract

J Hazard Mater. 2004 Jan 2;106(1):85-97.
 
Groundwater quality in some villages of Haryana, India: focus on fluoride and fluorosis.

Meenakshi, Garg VK, Kavita, Renuka, Malik A.

Department of Environmental Sciences and Engineering, Guru Jambheshwar University, Hisar, 125001, Haryana, India

The fluoride concentration in underground water was determined in four villages of Jind district of Haryana state (India) where it is the only source of drinking water. Various other water quality parameters such as pH, electrical conductivity, total dissolved salts, total hardness, total alkalinity as well as sodium, potassium, calcium, magnesium, carbonate, bicarbonate, chloride and sulfate concentrations were also measured. A systematic calculation of correlation coefficients among different physico-chemical parameters was performed. The analytical results indicated considerable variations among the analyzed samples with respect to their chemical composition. Majority of the samples do not comply with Indian as well as WHO standards for most of the water quality parameters measured. The fluoride concentration in the underground water of these villages varied from 0.3 to 6.9mg/l, causing dental fluorosis among people especially children of these villages. Overall water quality was found unsatisfactory for drinking purposes without any prior treatment except at eight locations out of 60.

PMID: 14693439 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14687642&dopt=Abstract

Appl Radiat Isot. 2004 Jan;60(1):99-104.
 
Impact of fluoride and other aquatic parameters on radon concentration in natural waters.

Salih I, Backstrom M, Karlsson S, Lund E, Pettersson HB.

Department of Radiation Physics, IMV, Faculty of Health Sciences, Linkoping University, S-581 85, Linkoping, Sweden

Radon (222Rn) accumulation in water in relation to stable elements was studied for the purpose of determining factors influencing the transfer of 222Rn to and from water. In 72 groundwater samples, 222Rn and about 70 analytical parameters were analysed using radiometric and ICP-MS techniques. Using multivariate statistics (partial least squares), it was observed that 222Rn has a positive correlation with fluoride and uranium. The correlation with fluoride was further investigated by a laboratory time-scale experiment to measure the emanation of 222Rn from water as a function of fluoride, pH and carbonate. The transfer of 222Rn from water was measured by continuous monitoring in air in a closed loop set-up. It was observed that fluoride in water adhere or trap 222Rn preferably in acidic water (pH 3). It is suspected that natural physical processes (such as diffusion and microbubble phenomenon) are less effective to transport 222Rn in the presence of fluoride.

PMID: 14687642 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14644914&dopt=Abstract

Ann Bot (Lond). 2004 Jan;93(1):97-105. Epub 2003 Nov 26.
 
The impact of pH and calcium on the uptake of fluoride by tea plants (Camellia sinensis L.).

Ruan J, Ma L, Shi Y, Han W.

Tea Research Institute of Chinese Academy of Agricultural Sciences and Key Laboratory for Tea Chemistry of The Ministry of Agriculture of China, Hangzhou, 310008, China. jruan@plantnutrition.uni-kiel.de

BACKGROUND AND AIMS: Tea plants (Camellia sinensis L.) accumulate large amounts of fluoride (F) from soils containing normal F concentrations. The present experiments examined the effects of pH and Ca on F uptake by this accumulating plant species.
METHODS: The effect of pH was assessed in two experiments, one using uptake solutions with different pHs, and the other using lime, as CaO, applied to the soil. The effect of Ca was examined by analysing F concentrations in plants supplied with varying amounts of Ca, as Ca(NO3)2, either in uptake solutions or through the soil.
KEY RESULTS: F uptake was highest at solution pH 5.5, and significantly lower at pH 4.0. In the soil experiment, leaf F decreased linearly with the amounts of lime, which raised the soil pH progressively from 4.32 to 4.91, 5.43, 5.89 and, finally, 6.55. Liming increased the water-soluble F content of the soil. Including Ca in the uptake solution or adding Ca to soil significantly decreased leaf F concentrations. The distribution pattern of F in tea plants was not altered by Ca treatment, with most F being allocated to leaves. The activity of F- in the uptake solution was unaffected and water-soluble F in the soil was sometimes increased by added Ca.
CONCLUSIONS: F uptake by tea plants, which are inherently able to accumulate large quantities of F, was affected both by pH and by Ca levels in the medium. The reduced F uptake following Ca application appeared not to be due simply to the precipitation of CaF2 in solution and soil or to the complexing of Ca and F in roots, although these factors cannot be dismissed. It was more likely due to the effect of Ca on the properties of cell wall or membrane permeability in the solution experiments, and to alteration of F speciations and their quantities in soil solutions following Ca application.

PMID: 14644914 [PubMed - in process]

http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14760533&dopt=Abstract

Anat Embryol (Berl). 2004 Feb 4 [Epub ahead of print]

Fluoride-induced alterations of enamel structure: an experimental study in the miniature pig.

Kierdorf H, Kierdorf U, Richards A, Josephsen K.

Department of Biology, University of Hildesheim, Marienburger Platz 22, 31141, Hildesheim, Germany.

We studied the structural changes in the enamel of mandibular third molars of miniature pigs administered a daily oral dose of 2 mg NaF (approximately 0.9 mg of fluoride) per kg body weight (added to the feed) for 1 year. The treatment period covered most of the secretory stage and the entire post-secretory stage of amelogenesis of the M(3). The enamel of the molars from the fluoride-fed pigs appeared opaque and chalky, and the erupted portions were stained brown. The underlying histopathological change was a pronounced subsurface hypomineralization of the enamel beneath a thin surface rim of higher mineral content. This enamel hypomineralization was attributed to a fluoride-induced impairment of the process of enamel maturation. The most conspicuous finding in the fluorotic enamel was the presence of numerous pit-type hypoplastic defects, denoting a marked fluoride-induced disturbance also of the secretory stage of amelogenesis. Microradiography and scanning electron microscopy revealed an enhanced incremental pattern in the outer enamel of the fluorotic molars. Typically, the bottom of larger hypoplastic defects was underlain by a broad, grossly accentuated incremental line. Occurrence of larger hypoplasias was further associated with the presence of aprismatic enamel, the formation of which was attributed to a loss of the prism-forming (distal) portion of the Tomes' processes of secretory ameloblasts. The findings in the miniature pigs closely parallel earlier observations on fluorotic enamel of free-ranging deer and wild boar from fluoride-polluted areas.

PMID: 14760533 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15120498

Biomaterials. 2004 Aug;25(19):4535-4542.

Influence of fluoridated mouthwashes on corrosion resistance of orthodontics wires.

Schiff N, Grosgogeat B, Lissac MM, Dalard F.

School of Dentistry, University Claude Bernard Lyon 1, Interfaces and Biofilms Study Laboratory in Odontology, EA 637, Rue Guillaume Paradin, 69372 Lyon Cedex 08, France.

The aim of the present study was to classify the different alloys commonly used to make orthodontic wire according to their corrosion resistance in different media. The four materials analysed were titanium-based alloys: TMA, TiNb, NiTi and CuNiTi, which were tested in three fluoride mouthwashes: Elmex((R)), Meridol((R)) and Acorea((R)) as well as in Fusayama Meyer artificial saliva. The electrochemical study showed that the alloys could be divided into two groups. In one group were the NiTi-based alloys which were subject to strong corrosion in the presence of monofluorophosphate found in Acorea((R)) solution. In the other group were TiNb, which was the most resistant to corrosion, and TMA, which corroded strongly with the stannous fluoride found in Meridol((R)) mouthwash. The results obtained in the present study will enable us to provide attending practitioners with advice concerning fluoride mouthwash to recommend, depending on the treatment phase and the alloy used. So we can advise Elmex((R)) mouthwash for patients with TMA and NiTi-based orthodontics wires but we suggest Acorea((R)) or Meridol((R)) mouthwashes for patients with TiNb orthodontics wires.

PMID: 15120498 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15478274

Osiris. 2004;19:182-200.

The artificial nature of fluoridated water: between nations, knowledge, and material flows.

Sellers C.

History Department, Stony Brook University, Stony Brook, NY 11794. csellers@notes.cc.sunysb.edu

An exercise in "historical ontology," this paper charts the contrasting ways fluoridated water and its effects crystallized as objects of knowledge and concern in three quite different realms over the mid twentieth century. Among U.S. health officials and experts, fluoridated water emerged and stabilized as a public health goal, preventing tooth decay. Indian doctors and scientists defined it as a public health problem, causing "skeletal fluorosis." Fluoridated water also acquired an intense presence among laypeople in the United States, especially those voting in local referenda on fluoridation. More often than not rejecting it, suspecting bias and myopia in profluoridation expertise, they cobbled together a lay ontology that proved predictive of the varied and changing flows of fluoridated water itself. The paper concludes by suggesting a principle of environmental symmetry as an aid to this kind of comparative ontology.

Publication Types:
• Historical Article

PMID: 15478274 [PubMed - indexed for MEDLINE]

Note from EC: This is a well written article that offers an historical snapshot of fluoridation that is little discussed. One example is the discussion of the World Health Organization diplomacy in balancing the concerns of countries (eg, India) on the severe effects of fluoride overexposure with the promoters of fluoridation in the US.


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15473093

Int J Occup Environ Health. 2004 Jul-Sep;10(3):343-50.

Water fluoridation and the environment: current perspective in the United States.

Pollick HF.

Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California San Francisco, San Francisco, California 94143-0758, USA.

Evidence of water fluoridation's effects on plants, animals, and humans is considered based on reviews by scientific groups and individual communities, including Fort Collins, CO, Port Angeles, WA, and Tacoma-Pierce County, WA. The potential for corrosion of pipes and the use of fluoridation chemicals, particularly fluorosilicic acid, are considered, as is the debate about whether fluoridation increases lead in water, with the conclusion that there is no such increase. The arguments of anti-fluoridationists and fluoridation proponents are examined with respect to the politics of the issue.

PMID: 15473093 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14703372&dopt=Abstract

J Org Chem. 2004 Jan 9;69(1):1-11.
 
Perspective on fluorocarbon chemistry.

Lemal DM.

Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755.

Fluorocarbons, organic molecules with carbon skeletons and fluorine "skins", differ fundamentally from their hydrocarbon counterparts in interesting and useful ways. A selection of the myriad applications fluorocarbons and their derivatives have found in modern life is described and related to molecular properties. Salient aspects of the nature and reactivity of fluorocarbon compounds are highlighted by comparison with their more familiar hydrocarbon analogues.

PMID: 14703372 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15210027

J Oral Rehabil. 2004 Jul;31(7):665-70.

The release of ions by compomers under neutral and acidic conditions.

Nicholson JW, Czarnecka B.

School of Chemical and Life Sciences, University of Greenwich, Chatham Maritime, Chatham, Kent, UK.

summary Three commercial compomers have been studied for their interaction with aqueous solutions (i.e. water at pH 5.9 and lactic acid at pH 2.7). Light-cured discs of these materials (12.8 diameter x 1 mm depth; Dyract AP, Compoglass F and F2000) were prepared and stored in 5 cm(3) of either water or lactic acid at pH 2.7. After 1 week, mass changes, pH changes and ion-release were determined. For the specimens stored in water, the effect of maturation under neutral conditions was studied by continuing storage for 3 months, followed by storage in lactic acid for a further week after which ion release and pH change were determined. Student's t-test was used to determine statistical significance of any changes observed. All three cured compomers absorbed water and altered the pH of the solutions, though this was statistically significant only in lactic acid. They were found to release Na, Ca, Sr, Al, Si, P and F ions, with greater amounts being released in acidic conditions than neutral ones. More fluoride was released in acid than in water, but the proportion of free (uncomplexed) fluoride to bound (complexed) fluoride was much lower than in neutral conditions. This was attributed to the formation of strong complexes with aluminium. Maturing specimens for 3 months made very little difference to their interaction with the acid solution, except for the total release of fluoride, which was some two to three greater than from the immature specimens.

PMID: 15210027 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15116179

Chem Commun (Camb). 2004 May 7;(9):1050-1. Epub 2004 Apr 02.

A novel fluoride sensor based on fluorescence enhancement.

Xu G, Tarr MA.

Department of Chemistry, University of New Orleans, 2000 Lakeshore Drive, New Orleans, LA 70148, USA. mtarr@uno.edu

A novel halide sensor, which yields greater fluorescence upon binding to fluoride, has been synthesized and characterized.

PMID: 15116179 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15117186

Anal Chem. 2004 May 1;76(9):2478-81.
 
Detection of Femtomolar Concentrations of HF Using an SiO(2) Microcantilever.

Tang Y, Fang J, Xu X, Ji HF, Brown GM, Thundat T.

Institute for Micromanufacturing, Louisiana Tech University, Ruston, Louisiana 71270.

Femtomolar concentrations of hydrogen fluoride, a decomposition component of nerve agents, were detected using a SiO(2) microcantilever. The microcantilever underwent bending due to the reaction of HF with SiO(2). The microcantilever deflection increased as the concentration of HF increased. Other acids, such as HCl, had no effect on the deflection of the cantilever. The mechanism of reaction-induced bending and the correlation of microcantilever deflection with the HF concentration are discussed. The deflection in response to HF of a commercially available silicon cantilever was also studied, and its response was compared with that of the SiO(2) cantilever. Much less bending amplitude and sensitivity were observed for the silicon cantilever.

PMID: 15117186 [PubMed - in process]


http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15122637

Chembiochem. 2004 May 3;5(5):650-655.

The Coordination Chemistry of Fluorine in Fluorocarbons.

Plenio H.

Institut fur Anorganische und Physikalische Chemie, TU Darmstadt, Petersenstrasse 18, 64287 Darmstadt, Germany, Fax: (+49) 6151-16-6040.

No Abstract

PMID: 15122637 [PubMed - as supplied by publisher]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15173904

J Environ Monit. 2004 Jun;6(6):523-32. Epub 2004 Mar 22.

Characterization of physicochemical properties of beryllium aerosols associated with prevalence of chronic beryllium disease.

Stefaniak AB, Hoover MD, Day GA, Dickerson RM, Peterson EJ, Kent MS, Schuler CR, Breysse PN, Scripsick RC.

Industrial Hygiene and Safety Group (HSR-5), MS K553, Los Alamos National Laboratory, Los Alamos, NM 87545, USA. scrip@lanl.gov

Little is known about the physicochemical properties of beryllium aerosols associated with increased risk of beryllium sensitization and chronic beryllium disease (CBD). Such information is needed to evaluate whether airborne mass of beryllium is the appropriate metric of exposure or alternatively to provide a scientific basis for using information on particle size, surface area, and chemistry to support an improved exposure limit based on bioavailability through the inhalation and dermal routes of exposure. Thus, we used a suite of analytical techniques to characterize aerodynamically size-fractionated beryllium particles and powders that have been associated in epidemiological studies with higher prevalence of CBD. Aerosol particles were sampled from the ventilation systems of production lines for powders of beryllium metal and beryllium oxide and for ingots of copper-beryllium alloy. End product powders from the metal and oxide production lines were also collected.Particles released during production of beryllium metal were found to be complex, having heterogeneous composition, including reactive species such as fluorine. Powders from beryllium metal production were of high purity with only a minor component of beryllium oxide. Both particles and powders from oxide production were high-purity oxide. Particles released during production of copper-beryllium alloy were heterogeneous, being predominantly copper oxides. Thus, all particles and powders contain at least some beryllium in the form of beryllium oxide.These data justify efforts to thoroughly characterize beryllium aerosol properties when performing exposure assessments. The data also suggest that differences in particle chemical composition, size, number, and surface area may influence bioavailability of beryllium and contribute to risk of CBD. However, a scientific basis does not yet exist to replace mass as the current metric of exposure.

PMID: 15173904 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15239857

J Anal Toxicol. 2004 Jul-Aug;28(5):364-71.
 
Improvements of the fluoride reactivation method for the verification of nerve agent exposure.

Degenhardt CE, Pleijsier K, Van Der Schans MJ, Langenberg JP, Preston KE, Solano MI, Maggio VL, Barr JR.

TNO-Prins Maurits Laboratory, P.O. Box 45, 2280 AA Rijswijk, The Netherlands.

One of the most appropriate biomarkers for the verification of organophosphorus nerve agent exposure is the conjugate of the nerve agent to butyrylcholinesterase (BuChE). The phosphyl moiety of the nerve agent can be released from the BuChE enzyme by incubation with fluoride ions, after which the resulting organophosphonofluoridate can be analyzed with gas chromatography-mass spectrometry (GC-MS). This paper describes recent improvements of the fluoride-induced reactivation in human plasma or serum samples by enhancing the sample preparation with new solid-phase extraction cartridges and the MS analysis with large volume injections. Analysis is performed with thermal desorption GC with either mass selective detection with ammonia chemical ionization or high-resolution MS with electron impact ionization. The organophosphorus chemical warfare agents analyzed in this study are O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate, ethyl methylphosphonofluoridate, isopropyl methylphosphonofluoridate (sarin, GB), O-ethyl N,N-dimethylphosphoramidocyanidate, ethyl N,N-dimethylphosphoramidofluoridate, and cyclohexyl methylphosphonfluoridate. Detection limits of approximately 10 pg/mL plasma were achieved for all analytes, which corresponds to 0.09% inhibition with GB on a sample with normal BuChE levels.

PMID: 15239857 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15268960

Chemosphere. 2004 Sep;56(10):943-7.
 
Pressurised liquid-liquid extraction. An approach to the removal of inorganic non-metal species from used industrial oils.

Morales-Munoz S, Luque-Garcia JL, Luque De Castro MD.

Department of Analytical Chemistry, University of Cordoba, Annex C-3, Campus of Rabanales, E-14071 Cordoba, Spain.

Modified pressurised hot water is used for the development of a high pressure liquid-liquid extraction method for the decontamination of used industrial oils from inorganic non-metal species (chlorine, fluorine and sulphur). The oils were subjected to dynamic extraction with water modified with 5% v/v HNO(3) at 200 degrees C as extractant. Under these working conditions the analytes were transferred to the aqueous phase. Spontaneous separation of the two immiscible liquid phases (the used oil and extract) takes place in the collection flask after extraction. The treated and untreated oil samples were oxidised and the chloride, fluoride and sulphate thus formed were determined by ion-chromatography. The method was applied to four oil samples from different locations in Spain. A residence time of ?10 min provided oil samples from which 88.3%, 89.4% and 89.4% of chloride, fluoride and sulphate, respectively, have been removed with respect to the initial concentration of each analyte in the oil. The repeatability, expressed as relative standard deviation (RSD), was of 11.9%, 13.7% and 7.2% for Cl(-), F(-) and SO(4)(2-), respectively; whilst the within-laboratory reproducibility yielded RSDs of 6.2%, 7.9% and 6.2% for the same analytes. The proposed approach has proved to be efficient, simple, easily transferable to industrial scale, cheap, fast and environmentally friendly.
PMID: 15268960 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15267329

J Chem Phys. 2004 Mar 8;120(10):4690-5.
 
Dissociation of hydrogen fluoride in HF(H(2)O)(7).

Kuo JL, Klein ML.

Department of Chemistry and Center for Molecular Modeling, University of Pennsylvania, Philadelphia, Pennsylvania 19104.

We have previously demonstrated that H-bond arrangement has a significant influence on the energetics, structure and chemistry of water clusters [J.-L. Kuo, C. V. Ciobanu, I. Shavitt, L. Ojamae, and S. J. Singer, J. Chem. Phys., 118, 3583 (2003)]. In this work, the effect of H-bond orientation on the dissociation of hydrogen fluoride with seven water molecules is studied by means of graph theory and high level ab initio methods. It is found that cubic structures of HF(H(2)O)(7) are more stable than structures of other topologies reported in the literature. Electronic calculations on all possible H-bond orientations of cubie-HF(H(2)O)(7) show that ionized structures are energetically more favorable than nonionized ones. This is an indication that seven water molecules might be capable of ionizing hydrogen fluoride. (c) 2004 American Institute of Physics.

PMID: 15267329 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15282758

J Mass Spectrom. 2004 Jul;39(7):791-801.
 
An atmospheric pressure chemical ionization study of the positive and negative ion chemistry of the hydrofluorocarbons 1,1-difluoroethane (HFC-152a) and 1,1,1,2-tetrafluoroethane (HFC-134a) and of perfluoro-n-hexane (FC-72) in air plasma at atmospheric pressure.

Marotta E, Paradisi C, Scorrano G.

INTM del CNR-Sezione di Padova, Dipartimento di Scienze Chimiche, Universita di Padova, Via Marzolo 1, 35131 Padua, Italy.

A report is given on the ionization/dissociation behavior of the title compounds within air plasmas produced by electrical corona discharges at atmospheric pressure: both positive and negative ions were investigated at different temperatures using atmospheric pressure chemical ionization mass spectrometry (APCI-MS). CHF(2)CH(3) (HFC-152a) undergoes efficient ionic oxidation to C(2)H(5)O(+), in which the oxygen comes from water present in the plasma. In contrast, CF(3)CH(2)F (HFC-134a) does not produce any characteristic positive ion under APCI conditions, its presence within the plasma being revealed only as a neutral ligand in ion-molecule complexes with ions of the background (H(3)O(+) and NO(+)). Analogously, the perfluorocarbon FC-72 (n-C(6)F(14)) does not produce significant positive ions at 30 degrees C: at high temperature, however, it undergoes dissociative ionization to form many product ions including C(3)F(6)(+), C(2)F(4)(+), C(n)F(2n+1)(+) and a few families of oxygen containing cations (C(n)F(2n+1)OH(2)(+), C(n)F(2n)OH(+), C(n)F(2n-1)O(+), C(n)F(2n-1)O(2)H(2)(+), C(n)F(2n-2)O(2)H(+)) which are suggested to derive from C(n)F(2n+1)(+) in a cascade of steps initiated by condensation with water followed by steps of HF elimination and H(2)O addition. Negative ions formed from the fluoroethanes CHF(2)CH(3) and CF(3)CH(2)F (M) include complexes with ions of the background, O(2)(-)(M), O(3)(-)(M) and some higher complexes involving also water, and complexes of the fluoride ion, F(-)(H(2)O), F(-)(M) and higher complexes with both M and H(2)O also together. The interesting product O(2)(-)(HF) is also formed from 1,1-difluoroethane. In contrast to the HFCs, perfluoro-n-hexane gives stable molecular anions, M(-), which at low source temperature or in humidified air are also detected as hydrates, M(-)(H(2)O). In addition, in humidified air F(-)(H(2)O)(n) complexes are also formed. The reactions leading to all major positive and negative product ions are discussed also with reference to available thermochemical data and relevant literature reports. The effects on both positive and negative APCI spectra due to ion activation via increasing V(cone) are also reported and discussed: several interesting endothermic processes are observed under these conditions. The results provide important information on the role of ionic reactions in non-thermal plasma processes.

PMID: 15282758 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15283562

Anal Chem. 2004 Aug 1;76(15):4286-91.
 
Detection of chemicals by a reporter immunoassay: application to fluoride.

Sagot MA, Heutte F, Renard PY, Dolle F, Pradelles P, Ezan E.

CEA, Service de Pharmacologie et d'Immunologie, Service de Marquage Moleculaire et de Chimie Bioorganique and IRCOF, UMR CNRS6014, 76131 Mont St-Aignan, and CEA, Service Hospitalier Frederic Joliot CE-Saclay, 91191 Gif-sur-Yvette, France.

This report describes a concept in which an immunoassay is used indirectly to quantify a nonantigenic very low molecular weight compound participating in a chemical reaction with a haptenic reporter. The detection limit of each reagent is, therefore, governed only by the affinity of the antibodies toward the reporter. Fluoride was used as a model, and silylated estradiol was used as a reporter. Upon silylation with N-O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) or N-O-bis(dimethylterbutylsilyl) trifluoroacetamide (MTBSTFA), estradiol is no longer recognized by antibodies specific to estradiol. After reaction with hydrofluoric acid (HF) or fluoride salts (KF, CsF, NaF), its immunoreactivity is restored, and native estradiol is formed and is detected by immunoassay. The level of synthesized estradiol is dependent on the concentration of fluoride. A fluoride detection limit of 0.3 microg/L (15 nM) is obtained. Potential interference with other acids has been eliminated by choosing the silyl group (trimethylsilyl vs tert-butyldimethylsilyl) and by selecting optimal reaction conditions for the desilylation. The method has been applied to the detection of fluoride salts in natural waters (range 0.28-9.0 mg/L) and in an atmosphere artificially contaminated with HF between 8 and 160 microg/m(3) in the parts-per-billion range. This indirect immunoassay combines simplicity and high sensitivity and, therefore, can be used in field monitoring. Finally, the extension of the concept to other chemicals is discussed.

PMID: 15283562 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15239856

J Anal Toxicol. 2004 Jul-Aug;28(5):357-63.
 
Quantitation of Fluoride Ion Released Sarin in Red Blood Cell Samples by Gas ChromatographyEthChemical Ionization Mass Spectrometry Using Isotope Dilution and Large-Volume Injection.

Jakubowski EM, McGuire JM, Evans RA, Edwards JL, Hulet SW, Benton BJ, Forster JS, Burnett DC, Muse WT, Matson K, Crouse CL, Mioduszewski RJ, Thomson SA.

Research and Technology Directorate, U.S. Army ECBC, APG-EA, Edgewood, Maryland 21010.

A new method for measuring fluoride ion released isopropyl methylphosphonofluoridate (sarin, GB) in the red blood cell fraction was developed that utilizes an autoinjector, a large-volume injector port (LVI), positive ion ammonia chemical ionization detection in the SIM mode, and a deuterated stable isotope internal standard. This method was applied to red blood cell (RBC) and plasma ethyl acetate extracts from spiked human and animal whole blood samples and from whole blood of minipigs, guinea pigs, and rats exposed by whole-body sarin inhalation. Evidence of nerve agent exposure was detected in plasma and red blood cells at low levels of exposure. The linear method range of quantitation was 10-1000 pg on-column with a detection limit of approximately 2-pg on-column. In the course of method development, several conditions were optimized for the LVI, including type of injector insert, injection volume, initial temperature, pressure, and flow rate. RBC fractions had advantages over the plasma with respect to assessing nerve agent exposure using the fluoride ion method especially in samples with low serum butyrylcholinesterase activity.

PMID: 15239856 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15308181

Appl Radiat Isot. 2004 Nov;61(5):993-6.
 
Flux and instrumentation upgrade for the epithermal neutron beam facility at Washington State University.

Nigg DW, Venhuizen JR, Wemple CA, Tripard GE, Sharp S, Fox K.

Idaho National Engineering and Environmental Laboratory, 2525 North Fremont Street, PO Box 1625, MS 3860, Idaho Falls, ID 83415-3855, USA.

An epithermal neutron beam facility for preclinical neutron capture therapy research has been constructed at the Washington State University TRIGA research reactor installation. Subsequent to a recent upgrade, this new facility offers a high-purity epithermal beam with intensity on the order of 1.2x10(9)n/cm(2)s. Key features include a fluoride-based design for the neutron filtering and moderating components as well as a novel collimator design that allows ease of assembly and disassembly of the beamline components.

PMID: 15308181 [PubMed - in process]


http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15293254

Angew Chem Int Ed Engl. 2004 Jul 5;43(27):3588-90.
 
An unusually fast nucleophilic aromatic displacement reaction: the gas-phase reaction of fluoride ions with nitrobenzene.

Giroldo T, Xavier LA, Riveros JM.

Institute of Chemistry, University of Sao Paulo, Caixa Postal 26 077, Sao Paulo CEP 05513-970, Brazil.

No Abstract available

PMID: 15293254 [PubMed - in process]


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