2005 Fluoride Abstracts. Part 2. Compiled by Fluoride Action Network Pesticide Project

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16303218&query_hl=1

J Environ Radioact. 2005 Nov 18; [Epub ahead of print]

Naturally occurring radioactive material (NORM) from a former phosphoric acid processing plant.

Beddow H, Black S, Read D.

Geoscience Building, School of Human and Environmental Sciences, Whiteknights, PO Box 227, University of Reading, Reading, Berkshire RG6 6AB, UK.

In recent years there has been an increasing awareness of the radiological impact of non-nuclear industries that extract and/or process ores and minerals containing naturally occurring radioactive material (NORM). These industrial activities may result in significant radioactive contamination of (by-) products, wastes and plant installations. In this study, scale samples were collected from a decommissioned phosphoric acid processing plant. To determine the nature and concentration of NORM retained in pipe-work and associated process plant, four main areas of the site were investigated:

(1) the 'Green Acid Plant', where crude acid was concentrated;
(2) the green acid storage tanks;
(3) the Purified White Acid (PWA) plant, where inorganic impurities were removed; and
(4) the solid waste, disposed of on-site as landfill.

The scale samples predominantly comprise the following: fluorides (e.g. ralstonite); calcium sulphate (e.g. gypsum); and an assemblage of mixed fluorides and phosphates (e.g. iron fluoride hydrate, calcium phosphate), respectively. The radioactive inventory is dominated by (238)U and its decay chain products, and significant fractionation along the series occurs. Compared to the feedstock ore, elevated concentrations (</=8.8Bq/g) of (238)U were found to be retained in installations where the process stream was rich in fluorides and phosphates. In addition, enriched levels (</=11Bq/g) of (226)Ra were found in association with precipitates of calcium sulphate. Water extraction tests indicate that many of the scales and waste contain significantly soluble materials and readily release radioactivity into solution.

PMID: 16303218 [PubMed - as supplied by publisher]

From Science Direct

Journal of Fluorine Chemistry - Volume 126, Issue 2 , February 2005, Pages 157-163

Selected papers presented at the XIVth EUROPEAN SYMPOSIUM ON FLUORINE CHEMISTRY This Document

Fluorine chemistry at the millennium

William R. Dolbier, Jr.,

Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA

Some Excerpts:

Landmark events in the history of fluorine chemistry
• 1886 Moissan's isolation of elemental fluorine.
• 1892 Swarts’ discovery of the Cl/F exchange chemistry of SbF3.
• 1928 Midgley's invention of “Freons®”.
• 1938 Plunkett's discovery of “Teflon®” and birth of fluoropolymers.
• 1947 Fowler's discovery of the CoF3 method of perfluorination.
• 1949 Simons’ discovery of electrochemical fluorination.
• 1954 Fried's initial pioneering work in “medicinal” fluorine chemistry.
• 1962 Bartlett's discovery of noble gas chemistry (preparation of XePtF6).
• 1974 Molina and Rowland's model of ozone depletion by CFC's published.
• 1979 Margraves’ “direct” perfluorination discoveries.
• 2003 O’Hagan's isolation of the first fluorinating enzyme.

Scheme 1. Natural occurring fluoroorganic compounds [10]
In spite of the strong bonds between carbon and fluorine, and in spite of the fact that fluorine is a very common element in the earth's crust (13th most abundant), nature has generally found it difficult to incorporate fluorine into naturally occurring molecules, perhaps because of the very strong energy of solvation of fluoride ion in water. The known list of natural products containing fluorine is short indeed and it is presented in Scheme 1
In spite of the strong bonds between carbon and fluorine, and in spite of the fact that fluorine is a very common element in the earth's crust (13th most abundant), nature has generally found it difficult to incorporate fluorine into naturally occurring molecules, perhaps because of the very strong energy of solvation of fluoride ion in water. The known list of natural products containing fluorine is short indeed and it is presented in Scheme 1 [10]:

Biologically active fluorochemicals
The application of fluorine-containing compounds to the fields of pharmaceuticals and agrochemicals has a very short history, beginning only about 35 years ago. Especially significant to these developments was the pioneering work of Fried, who, beginning in 1954 [34], demonstrated the potential importance of fluorine substituents in enhancing the efficacy of drugs through a number of noteworthy studies [35].However, until the 1970s, fluorinated compounds were only rarely encountered in medicinal and agrochemicals, a situation that has changed dramatically since that time. Now, fluorine-containing drug and agrochemical candidates are routinely synthesized as a matter of course. At present, there are 128 fluorinated compounds with US trade names, including 9 of 31 new drugs approved in 2002, according to the World Drug Index [36]. Two well-known examples of fluorine-containing drugs are given below:

The small size of the fluorine substituent, combined with its high electronegativity and its impact upon bond strengths give rise to the observed distinctive effect of fluorine substituents upon biological activity of compounds. In the area of medicinal chemistry, incorporation of fluorine plays a significant role in the development of new anti-cancer and anti-viral agents, anti-inflammatory and anti-hyperintensive agents, anti-fertility drugs and central nervous system drugs. In the area of modern crop protection, fluoro agrochemicals include herbicides, insecticides and fungicides [37]. Fluorine affects the biological activity of compounds in a number of important ways. The presence of fluorine at a particular position in a molecule can enhance its metabolic stability or modulate its physicochemical properties, such as its lipophilicity, acidity or basicity. Fluorination can increase a molecules binding affinity to a target protein, and by a combination of factors interfere with specific enzyme action.
As a result, fluorine plays a huge role in the current areas of pharmaceutical chemistry and agrochemistry, with many of the most important new drugs and agents containing propitiously placed fluorine, trifluoromethyl, difluoromethyl or other fluorinated groups.

Fluorinated materials
... In recent years, liquid crystal displays (LCDs) have become an almost indispensable part of our daily life. Among the most rapidly growing applications are full-color, flat-screen displays capable of high-resolution graphics, as seen in computer monitors and “hang-on-the-wall” TV screens. Because of fluorine's high electronegativity and thus strong electron-withdrawing effect, in relation to its small size, the presence of fluorine in a liquid crystal exerts a large influence on permittivity, while causing minimum change in molecular shape, and the “flat-screen” technology would not be possible without liquid crystals such as those shown below [39] and [41].

References:
10. .....D. O’Hagan, in: Proceedings of the International Symposium on Fluorine in the Life Sciences Bürgenstock (2003).
34. .....J.H. Fried and E.F. Sabo, J. Am. Chem. Soc. 76 (1954), pp. 1455–1456.
35. .....J.H. Fried, V. John, M.J. Szwedo Jr., C.-K. Chen, C. O’Yang, T.A. Morinelli, A.K. Okwu and P.V. Halushka, J. Am. Chem. Soc. 111 (1989), pp. 4510–4511.
36. .....H.-J. Böhm, D. Banner, S. Bendels, M. Kansy, B. Kuhn, K. Müller, U. Obst-Sander and M. Stahl, Chem. Biol. Chem. 5 (2004), pp. 637–643.
37. .....P. Jeschke, Chem. Biol. Chem. 5 (2004), pp. 570–589.
39. .....T. Inoi In: R.E. Banks, B.E. Smart and J.C. Tatlow, Editors, Organofluorine Chemistry: Principles and Commercial Applications, Plenum Press, New York (1994), pp. 263–286.
41. .....P. Kirsch and M. Bremer, Angew. Chem. Int. Ed. 39 (2000), pp. 4216–4235.

Note from FAN: see also
Fluorine-containing natural products
David O’Hagan and David B. Harperb
Journal of Fluorine Chemistry
Volume 100, Issues 1-2 , December 1999, Pages 127-133

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16438356&query_hl=4&itool=pubmed_docsum

SADJ : Journal of the South African Dental Association - 2005 Nov;60(10):418-21.

Global trends in dental fluorosis from 1980 to 2000: a systematic review.

Khan A, Moola MH, Cleaton-Jones P.

Department of Community Dentistry, Faculty of Dentistry, University of Limpopo.

AIM: To determine trends in fluorosis prevalence at water fluoride levels <0.3, >0.3 to <0.7, and >0.7 to 1.4 ppm from 1980 to 2000.
METHODS: A systematic review of 55 published articles identified in a Medline search for peer-reviewed articles on fluorosis published from 1 January 1980 to 31 December 2000. The prevalence recorded with any fluorosis index was pooled and the trends over time were determined in the three water concentration categories.
RESULTS: The fluorosis prevalence for the three fluoride categories were 16.7, 27.4 and 32.2 percent, respectively. A 16-fold and a 2-fold increase in fluorosis prevalence compared with reported rates in the 1940s was seen in non-fluoridated (= 0.3 ppm F) and fluoridated (>0.7 to = 1.4 ppm F) areas, respectively. There has been an increase in fluorosis prevalence over time in the three fluoride water concentration categories but linear regression analysis showed that none are significantly different from zero.
CONCLUSION: This systematic review concurs with recent reports of an increase in fluorosis prevalence in fluoridated and non-fluoridated communities.

PMID: 16438356 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16146004&query_hl=19
Ann Univ Mariae Curie Sklodowska [Med]. 2004;59(1):317-20.

Comparison of fluorine level in the tissues of healthy teeth and teeth with decay process.

Pikula A, Kedra A, Salaga-Pylak M, Stadnik A, Sokolowska B, Borzecki A.

Department of Hygiene, Skubiszewski Medical University of Lublin.

The aim of the study was to examine quantitative fluorine content in tooth tissues with the decay process, tissues of teeth without decay and tissues with diseases different than those of decay origin. It has been found that in the examined teeth decay process the average fluorine content in hard tissues amounted to 235.6 ppm of fluorine and it was lower than in healthy teeth (304.8 ppm) extracted for orthodontic or periodontological reasons, whereas the highest fluorine content--383.5 ppm--was found in teeth with diseases of non-decay etiology. Analyzing particular teeth groups depending on the age of the patients, it was observed that the fluorine level is higher in the teeth received from younger patients, especially in the group of healthy teeth and teeth with wedge defects. Susceptibility of tooth enamel to dissolution was estimated by the CRT test with the use of discs impregnated with crystal violet (hexamethylene-4 hydrochloride of fuchsin) with the range of colour change from yellow and green to violet and blue at ph 0.1-1.5. The lengthening of the time of reaction in this test testified to lower acid sensitivity of tissues and at the same time to harder demineralization of enamel, e.g. in the process of decay. Longer time of reaction was observed in teeth with higher indicated fluorine content.

PMID: 16146004 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16112781&query_hl=19
Environ Pollut. 2005 Aug 18; [Epub ahead of print]

Growth and photosynthetic responses of two pine species (Pinus koraiensis and Pinus rigida) in a polluted industrial region in Korea.

Choi DS, Kayama M, Jin HO, Lee CH, Izuta T, Koike T.

Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.

We investigated the effects of pollutants on two pine species (Pinus koraiensis and Pinus rigida) in an industrial region in Korea, using a physiological approach. The concentrations of fluorine (F) and chlorine (Cl) in the atmosphere, in precipitation and soil water at the damaged site were all significantly higher than at a control site. Moreover, the concentrations of F, Cl and Mn in pine needles were significantly higher, and essential elements and chlorophyll in needles were significantly lower at the damaged site than at the control site. The photosynthetic capacities, shoot length and survival statistics of needles of the two pines were all significantly reduced at the damaged site compared to the control site, especially P. rigida. Based on our comparison of photosynthetic responses and the concentrations of F, Cl and Mn in needles of the two pine species, P. koraiensis is more resistant to excess Mn in its needles than P. rigida.

PMID: 16112781 [PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16099562&query_hl=19
Environ Pollut. 2005 Aug 11; [Epub ahead of print]

Radionuclides, heavy metals and fluorine incidence at Tapira phosphate rocks, Brazil, and their industrial (by) products.

da Conceicao FT, Bonotto DM.

Unidade Diferenciada Sorocaba/Ipero (UDSI), UNESP, Sorocaba, Ipero, Brazil.

Inorganic phosphate fertilizers may contain radionuclides, heavy metals and fluorine. This paper presents the possible environmental hazards from Tapira phosphate rocks and their (by) products (Brazil) utilized as phosphate fertilizers. The activity concentration of (238)U, (234)U, (226)Ra and (40)K in Tapira phosphate rocks is within the world range for these rock types. The (232)Th activity concentration is higher than the mean reported in phosphate rocks. A value of 2184nGy h(-1) was obtained for the exposure dose rate in Tapira phosphate deposit area, which is indicative of a high background radiation area. The flotation-separation process causes the incorporation of no more than 9%, 11% and 24% of radionuclides, heavy metals and fluorine, respectively, into the phosphate concentrate. The radionuclides and heavy metals existing in phosphate fertilizers applied in Brazilian crops according to the recommended rates, do not raise their concentration in soils to harmful levels.

PMID: 16099562 [PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16084562&query_hl=19
Chemosphere. 2005 Aug 3; [Epub ahead of print]

Total toxicity equivalents emissions of SF(6), CHF(3), and CCl(2)F(2) decomposed in a RF plasma environment.

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

Department of Bioenvironmental Engineering, Chung Yuan Christian University, No. 200, Chung Pei Road, Chung-Li 320, Taiwan.

Sulfur hexafluorine compound (SF(6)), trifluoromethane (CHF(3)) and diclorodifluoromethane (CCl(2)F(2)) are extensively used in the semiconductor industry. They are global warming gases. Most studies have addressed the effective decomposition of fluorine compounds, rather than the toxicity of decomposed by-products. Hence, the concepts of toxicity equivalents (TEQs) were applied in this work. The results indicated that HF and SiF(4) were the two greatest contributors of TEQ to the SF(6)/H(2)/Ar plasma system, while F(2) and SiF(4) were the two greatest contributors to the SF(6)/O(2)/Ar system. Additionally, SiF(4) and HF were the two greatest contributors of TEQ to both the CHF(3)/H(2)/Ar and CHF(3)/O(2)/Ar plasma systems. HF and HCl were the two greatest contributors of TEQ to the CCl(2)F(2)/H(2)/Ar plasma system, and Cl(2) and COCl(2) were the two greatest contributors to the CCl(2)F(2)/O(2)/Ar system. HCl and HF can be recovered using wet scrubbing, which reduces the toxicity of these emission gases. Consequently, the hydrogen-based plasma system was a better alternative for treating gases that contained SF(6), CHF(3) and CCl(2)F(2) from the TEQs point of view.

PMID: 16084562 [PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16027963&query_hl=19
Environ Geochem Health. 2005 Dec;27(4):285-8.

Dental caries in fluorine exposure areas in China.

Binbin W, Baoshan Z, Hongying W, Yakun P, Yuehua T.

Institute of Geochemistry, The Chinese Academy of Sciences, Guiyang, 550002, P.R. China. binbin.w@mailcity.com

In this study, fluorine concentrations in drinking water and in urine of residents from a fluorine exposure area in China were tested. DMFT (average number of decayed, missing and filled teeth) of local residents in four age groups were also determined. The results of the study indicate that in fluorine exposure areas, there is a strictly positive correlation between fluorine content in urine and the fluorine content in drinking water. Effect of dental caries by high fluorine content drinking water is different for the different age groups. High fluorine content drinking water is more dangerous for 15-and 18-year-old groups than 5- and 12-year-old groups.

PMID: 16027963 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16018176&query_hl=19
Tsitol Genet. 2005 Jan-Feb;39(1):34-40.

[Use of natural sorbents for removal of mutagens from liquid fluorine-organic waste products of monomer FC-141 manufacture]

[Article in Ukrainian]

Reveha OM, Fitel' NM, Bodnar LS, Kozub IuB.

Study of total mutagenic effects of liquid fluorine-organic waste products of monomer FC-141 manufacture has been carried out. Induction of gene mutations according to the mechanism of pair base replacement and shift of reading frame and induction of chromosomal aberrations, in particular deletions and translocations, has been shown. Expediency of use of natural sorbents for mutageneity removal from fluorine-organic waste products was investigated. Zeolites and glauconites appeared to be the most effective ones.

PMID: 16018176 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16044843&query_hl=48
Vopr Pitan. 2005;74(3):50-4.

[Stability of ascorbic acid at it contract alloy in presence of fluoride ions]

[Article in Russian]

[No authors listed]

Aluminum utensils are considered as potentiAl source of dietary Aluminums. Report suggests that acidic food cooked or stored in presence of Aluminum foil contain high concentrations of Aluminum. Study on fluoride induced leaching of Aluminum from different pH. Higher concentrations of fluoride and lower pH enhance Aluminum leaching to a great extent. Evidence was obtained showing that after a 2-dyas exposure at room temperature in presence of floride NaF, Aluminum foil liberated nearly 1 mg/l of Aluminum, compared with less than 0.04 mg/l in absence of fluoride. There is reason to believe that in experiments with ascorbic acid NaF prevents the oxidation of ascorbic acid.

PMID: 16044843 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16095064&query_hl=4
Acta Odontol Scand. 2005 Feb;63(1):56-63.

Prevalence of dental fluorosis in children from non-water-fluoridated Halmstad, Sweden: fluoride toothpaste use in infancy.

Conway DI, MacPherson LM, Stephen KW, Gilmour WH, Petersson LG.

Dental Public Health Unit, Level 8, University of Glasgow Dental Hospital and School, 378 Sauchiehall Street, Glasgow G2 3JZ, UK. D.Conway@dental.gla.ac.uk

OBJECTIVES: To determine the prevalence and severity of dental fluorosis in children aged 7-9 years from non-water-fluoridated Halmstad, Sweden, and to relate the results to their reported fluoride exposure history during infancy.
MATERIAL AND METHODS: In Spring 2002, a questionnaire distributed to a cluster random sample of 1039 parents enquired into their child's early oral health behaviors and included a "photographic toothpaste menu". The permanent upper anterior teeth (13-23) were examined clinically (+10% repeats) using a modified Thylstrup-Fejerskov Index.
RESULTS: Complete data were available for 53% (n=548) of the sampled children. The prevalence offluorosis at any level was 49% (95% CI: 45-54%), and of fluorosis with esthetic concern (TF score > or =3) 4% (95% CI: 3-6%). Based on repeat observations, reliability was good (kappa = 0.82). There was no statistically significant increased risk of dental fluorosis prevalence associated with any of the fluoride exposure risk factors examined, including reported usage of (1000 ppm) fluoride toothpaste from time of first deciduous tooth eruption.
CONCLUSIONS: While there were low levels of dental fluorosis of esthetic concern, half the children had some degree of dental fluorosis. The prevalence of dental fluorosis was not explained by the risk factors, including fluoride toothpaste usage as explored in this study.

PMID: 16095064 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16156172&query_hl=9
Schweiz Monatsschr Zahnmed. 2005;115(8):685-9.

Monitoring fluoride exposure with fingernail clippings.

Whitford GM.

Department of Oral Biology, School of Dentistry, Medical College of Georgia, Augusta, Georgia 30912-1129, USA. GWHITFOR@mail.mcg.edu

The purpose of this review is to discuss new information regarding the relationship between the level of fluoride exposure and the corresponding fluoride concentrations in fingernail clippings. While there are several techniques available to extract fluoride from fingernails prior to analysis with the electrode, the HMDS-facilitated diffusion method is the most popular. Fluoride enters fingernails at the growth end and reaches the distal end approximately three months later. The fluoride concentration in the clipping reflects the average fluoride intake and plasma concentration during the period when the clipping was formed. Therefore, the concentration in the clipping is directly related to the average fluoride exposure that occurred during a 1-2 week period (depending on the length of the clipping) about three months ago and not to recent and possibly variable exposures that occur during the day. Published studies have demonstrated that fingernail fluoride concentrations reflect fluoride exposures from drinking water, toothpaste and the work environment and can be expected to do so for any source of intake including salt.

PMID: 16156172 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16110207&query_hl=3
Caries Res. 2005 Sep-Oct;39(5):363-70.

Analysis of fingernails and urine as biomarkers of fluoride exposure from dentifrice and varnish in 4- to 7-year-old children.

Pessan JP, Pin ML, Martinhon CC, de Silva SM, Granjeiro JM, Buzalaf MA.

Department of Pediatric Dentistry, Orthodontics and Public Health, Bauru School of Dentistry, University of Sao Paulo, Bauru, SP, Brazil.

The use of fingernails and urine as biomarkers of exposure to fluoride (F) from fluoridated dentifrice and varnish was evaluated in twenty 4- to 7-year-old children, who were divided into two groups: group A (9 caries-free children) and group B (11 children with past caries experience). They used a placebo dentifrice for 28 days, fluoridated dentifrice (1,570 ppm F) for the following 28 days, and placebo dentifrice for an additional 28 days, then returned to their usual dentifrices. Group B children also received 4-week applications of a varnish (2.26% F) while using the fluoridated dentifrice. Urinary collections were performed 24 h before the use of fluoridated dentifrice and 24 h (group A) or 48 h (group B) after. Fingernails were clipped every 2 weeks, for 26 weeks. Total F intake from diet and dentifrice was estimated. Fingernail F concentrations did not vary significantly throughout the study. Twenty-four-hour urinary F outputs (mean +/- SD, microg) were: 414 +/- 200 and 468 +/- 253 for placebo and F dentifrices, respectively (group A) and 402 +/-206, 691 +/- 345, 492 +/- 243 for placebo dentifrice, F dentifrice plus F varnish and F dentifrice, respectively (group B). The use of F dentifrice did not cause a significant increase in the urinary F output. However, when F varnish was used, a transitory increase in the urinary F output was detected (p = 0.001), returning to baseline levels in the last 24 h. Thus, F varnish is a safe method for topical F application even in children that use F dentifrice regularly. According to our protocol, urine was a suitable biomarker of exposure to F from dentifrice plus varnish, but not from dentifrice alone, while nails were not.

PMID: 16110207 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16156171&query_hl=9
Schweiz Monatsschr Zahnmed. 2005;115(8):679-84.

Monitoring salt fluoridation programs through urinary excretion studies.

Marthaler TM, Schulte AG.

Clinic for Preventive Dentistry, Periodontology and Cariology, Dental Center, University of Zurich. tmarthal@zui.unizh.ch

This paper reviews problems associated with urinary collection for the estimation of fluoride exposure and recent findings in this context. After intake of a salted meal at noon, children aged 9 to 14 excreted on average 45 microgF/h. Morning and nocturnal excretions were only 16 microgF/h with the exception of those children who ate bread made with fluoridated salt (25 microF/h). Fluoride excretions in children consuming drinking water with 0.6 to 0.8 ppmF were similar, but the variations within the 24 h period were smaller. When it is not feasible to obtain reliable 24 h urinary collections, fairly precise extrapolations of 24 h excretions can be obtained from three separate collections lasting about 16 hours, which should cover morning, early afternoon and the whole night. Three- to six-year-old children benefitting from optimal fluoride supply through water or milk excreted approximately 0.35 to 0.40 mgF/24 h; this range seems to correspond to an optimal usage of fluorides. Studies on urinary fluoride excretion, like those on total fluoride intake, cannot be carried out on random samples. Due to the necessity of close cooperation of parents and children, such studies were done with "convenience" samples. In westernized countries with now low caries prevalence, intermittent high urinary excretions occur frequently. Possible sources are fluoride intake from concentrated oral care products (fluoride gels, fluoride chewing gums) or from dentifrices (containing 1000 to 1500 ppmF), mineral waters, industrial tea preparation or fluoride tablets (or other supplements). These problems do not affect the amount of fluoride in fingernail clippings which appear to be suitable for the routine monitoring of fluoride exposure.

PMID: 16156171 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16156170&query_hl=9
Schweiz Monatsschr Zahnmed. 2005;115(8):675-8.

Fluoride metabolism when added to salt.

Whitford GM.

Department of Oral Biology, School of Dentistry, Medical College of Georgia, Augusta, Georgia 30912-1129, USA. GWHITFOR@mail.mcg.edu

The purpose of this review is to present the general characteristics of the metabolism of fluoride particularly as it occurs when ingested with fluoridated salt. Following the absorption of salt-borne fluoride from the stomach and intestines, its metabolism is identical to that of water-borne fluoride or other vehicles containing ionized fluoride. Because fluoridated salt is almost always ingested with food, however, absorption from the gastrointestinal tract may be delayed or reduced. Reports dealing with this subject have shown that fluoride absorption is delayed and, therefore, peak plasma concentrations are lower than when fluoride is ingested with water. The amount of ingested fluoride that is finally absorbed, however, is not appreciably affected unless the meal is composed mainly of components with high calcium concentrations. In this case, the extent of absorption can be reduced by as much as 50%. Fluoridated salt is also ingested less frequently than fluoridated water. Data are presented to show that the dose size and frequency of ingestion have only minor effects on fluoride retention in the body and on the concentrations in plasma, bone and enamel. Finally, calculations are presented to show that the risk of acute toxicity from fluoridated salt is virtually non-existent.

PMID: 16156170 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16156169&query_hl=9
Schweiz Monatsschr Zahnmed. 2005;115(8):670-4.

Salt fluoridation in Central and Eastern Europe.

Marthaler TM, Pollak GW.

Clinic for Preventive Dentistry, Periodontology and Cariology, Center for Dentistry, University of Zurich. tmarthal@zui.unizh.ch

For decades Central European countries have been interested in preventive dentistry. Water fluoridation played a major role in the former German Democratic and Czechoslovak Republics and a minor one in Poland. These schemes were abandoned after 1989. Extensive research on all aspects of salt fluoridation was conducted in Hungary from 1966 to 1984 but attempts to introduce it in the country have had little success. Salt fluoridation was implemented in the Czech and the Slovak Republics in the mid-nineties. The market share of the fluoridated domestic salt appears to have reached 35% in the Czech Republic; it became eventually part of a preventive strategy comprising school-based dental health education including topical fluoride. Another four countries have been considering salt fluoridation but schemes did not materialize. Antifluoridation activities occasionally impeded caries prevention, and for years some respected dentists declared their position against fluorides. Caries prevalence in 12-year-old children is by 1 to 3 DMFT higher than in Western Europe. For many years to come, modern fluoride-containing toothpastes and dentifrices may not be affordable for the lower socio-economic strata of the populations in Central and Eastern Europe. It is concluded that salt fluoridation, which is by far the cheapest means of lowering caries prevalence, could markedly improve the oral health situation even if the economical situation is slow to improve.

PMID: 16156169 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16156168&query_hl=9
Schweiz Monatsschr Zahnmed. 2005;115(8):663-9.

Development of salt fluoridation in the Americas.

Gillespie GM, Baez R.

Department of Epidemiology (Oral Health), University College, 19 Torrington Place, London WC, England. gmgc@msn.com

Fluoridation of water supplies has proven to be an effective preventive measure for dental caries. Many developing countries in the Americas have multiple water systems and economies that do not permit the viable application of this approach. Some of the highest dental caries prevalence in the world was evident in the Americas. Fluoridated salt was considered as a potential solution on account of the urgent need for dental caries prevention to millions of people with limited access to routine dental services. A fluoridated salt trial was initiated in Colombia (1963) and upon successful completion with preventive results comparable to water fluoridation, the approach was introduced to other countries and was supported by resolutions of WHO, PAHO, regional health groups and the FDI. The procedures for addition of fluoride were comparable to those for iodization and the two elements were compatible. In the period 1972-2004, ten countries introduced national or localized programmes and five more initiated programmes. Results, based on addition of F ion at 200-250 mg/kg salt, indicated caries prevalence reductions in 12 year olds ranging from 84% in Jamaica, 73% in Costa Rica to 40% in Uruguay at an average cost of 0.06 U.S. dollars /capita/year. This paper provides a background to the situation in the Americas, illustrates the approaches and feasibility of implementing viable fluoridated salt programmes in countries, and demonstrates the results obtainable at minimum cost.

PMID: 16156168 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16156167&query_hl=9
Schweiz Monatsschr Zahnmed. 2005;115(8):659-62.

Salt fluoridation in Germany since 1991.

Schulte AG.

Department of Conservative Dentistry, University of Heidelberg, Germany. andreas_schulte@med.uni-heidelberg.de

Since 1991, fluoridated salt has been on sale in household-size packages in Germany. Potassium or sodium fluoride is added to iodized salt until the fluoride concentration reaches 250 mg/kg. The use of fluoridated salt to prevent caries is officially recommended by the Deutsche Gesellschaft fur Zahn-, Mund- und Kieferheilkunde (DGZMK) and several other associations and groups interested in public health. In the course of the past thirteen years, the market share of fluoridated and iodized domestic salt rose to 63.1% in Germany. However, this positive development must not obscure the fact that fluoridated and iodized salt is still not allowed to be used in restaurant or cafeteria kitchens. This restriction now needs to be revoked in view of the fact that many children, adolescents and adults take their main meals in cafeterias or restaurants. Scientific studies have demonstrated beyond doubt that using fluoridated and iodized salt in cafeteria kitchens poses no problem whatever.

PMID: 16156167 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16156166&query_hl=9
Schweiz Monatsschr Zahnmed. 2005;115(8):656-8.

Salt fluoridation in France since 1986.

Tramini P.

Service de Sante Publique, U.F.R. d'Odontologie, Universite de Montpellier I, France. paul.tramini@wanadoo.fr

In 1985, the production and use of fluoridated salt was authorized in France. Domestic salt both with added fluoride (at 250 ppm) and without fluoride has been on the market since 1986. It was recommended to avoid the consumption of fluoridated salt if the local drinking water contained more than 0.5 milligrams of fluoride per litre. The legislation has never been modified since, except for a few developments such as the permission given to school canteens in 1993 to use fluoridated salt, provided canteen managers made sure that the drinking water contained no more than 0.5 milligrams of fluoride per litre. Epidemiological surveys about fluoridated salt in France are few, but they point in the same direction: decrease of DMFT and DMFS values, evident for the period 1986-1993 but minimal from 1993 to 1998. In 1999 and 2002, epidemiological comparative surveys were carried out in Montpellier (France) and Heidelberg (Germany) among 12-year-old schoolchildren. A decrease in caries prevalence was found in both towns, particulary in Heidelberg. On the other hand, the two cities showed some slight differences resulting from public health policy, from individual preventive habits, and from an earlier introduction of fluoridated salt in France.

PMID: 16156166 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16156165&query_hl=9
Schweiz Monatsschr Zahnmed. 2005;115(8):651-5.

Overview of salt fluoridation in Switzerland since 1955, a short history.

Marthaler TM.

Clinic for Preventive Dentistry, Periodontology and Cariology, Dental Center, University of Zurich. tmarthal@zui.unizh.ch

After an early start in 1955, the introduction and acceptance of fluoridated salt (FS) for domestic use was slow in Switzerland because up to around 1980 there was no consistent strategy for the support of the use of FS. Part of the dental community still supported water fluoridation, while others criticized the insufficient concentration of fluoride in the salt (90 ppm). All Swiss cantons have a historical monopoly on salt trade, and until 1983 most cantonal governments resolved to authorize the sale of fluoridated domestic salt. Some of the cantonal governments made fluoridated salt the only available type of "kitchen salt" in 1-kg packages. After the concentration had been increased to 250 ppm in 1983, the use of FS gained further acceptance. A temporary setback occurred in 1992-1994, but was successfully met with by making the FS available in several package sizes, while other types of salt (with or without iodine) were available in 500 g packages only. By 2004, the market share of fluoridated domestic salt reached 88%. Further endeavours aim at increasing the use of FS by large kitchens. FS is available in portions of 12.5 kg (since 2001) and 25 kg (since 1976).

PMID: 16156165 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16034911&query_hl=13
Cochrane Database Syst Rev. 2005 Jul 20;(3):CD003876.

Fluoridated milk for preventing dental caries.

Yeung C, Hitchings J, Macfarlane T, Threlfall A, Tickle M, Glenny A.

Unit of Dental Public Health, School of Dentistry, University of Manchester, Higher Cambridge Street, Manchester, UK, M15 6FH.

BACKGROUND: Dental caries remains a major public health problem in most industrialised countries, affecting 60% to 90% of school children and the vast majority of adults. Milk provides a relatively cost-effective vehicle for fluoride in the prevention of dental caries.
OBJECTIVES: To determine the effectiveness of fluoridated milk, as a means of delivering fluoride on a community basis, for preventing dental caries. SEARCH STRATEGY: We searched Cochrane Oral Health Group Trials Register (28 April 2005), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2005), MEDLINE (1966 to 17 May 2005), OLDMEDLINE (1950 to 1965), EMBASE (1980 to 2005 week 20), LILACS (1982 to 17 May 2005), BBO (1986 to 17 May 2005), SIGLE (1980 to 17 May2005), Digital Dissertations (1861 to 17 May 2005) and reference lists of relevant articles. Attempts were made to identify both unpublished and ongoing studies. There were no language restrictions.
SELECTION CRITERIA: Randomised or quasi-randomised controlled trials (RCTs), with an intervention or follow-up period of at least 3 years, comparing fluoridated milk with non-fluoridated milk. Primary outcome was change in caries experience, as measured by changes in decayed, missing and filled figures on tooth (dmft/DMFT) and surface (dmfs/DMFS).
DATA COLLECTION AND ANALYSIS: Inclusion decisions, data extraction and quality assessment were carried out independently and in duplicate. Study authors were contacted for additional information where necessary.
MAIN RESULTS: Two RCTs involving 353 children were included. For permanent teeth, after 3 years there was a significant reduction in the DMFT (78.4%, P < 0.05) between the test and control groups in one trial, but not in the other. The latter study only showed a significant reduction in the DMFT until the fourth (35.5%, P < 0.02) and fifth (31.2%,P < 0.05) years. For primary teeth, again there was a significant reduction in the dmft (31.3%, P< 0.05) between the test and control groups after 3 years in one study, but not in the other. The results could not be pooled because of the difference in concentration of fluoride in the milk.
AUTHORS' CONCLUSIONS: There are insufficient studies with good quality evidence examining the effects of fluoridated milk in preventing dental caries. However, the included studies suggested that fluoridated milk was beneficial to school children, especially their permanent dentition. The data need to be supplemented by further RCTs to provide the highest level of evidence for practice.

PMID: 16034911 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16109993&query_hl=3
J Dent Res. 2005 Sep;84(9):832-6.

Fluorosis: a new model and new insights.

Bartlett JD, Dwyer SE, Beniash E, Skobe Z, Payne-Ferreira TL.

Department of Biomineralization and Department of Cytokine Biology, The Forsyth Institute, and Department of Oral and

Developmental Biology, Harvard School of Dental Medicine, 140 The Fenway, Boston, MA 02115, USA;

Fluoride is an effective agent for the prevention of dental caries. However, the mechanism of how excessive fluoride exposure causes fluorosis remains uncertain. Zebrafish (Danio rerio) exhibit periodic tooth replacement throughout their lives, thereby providing continuous access to teeth at developmental stages susceptible to fluoride exposure. Zebrafish teeth do not contain true enamel, but consist of a hard enameloid surface. Therefore, we asked whether zebrafish could be used as a model organism for the study of dental fluorosis. Scanning electron microscopy of fluoride-treated teeth demonstrated that the enameloid was pitted and rough, and FTIR analysis demonstrated that the teeth also contained a significantly higher organic content when compared with untreated controls. Furthermore, we demonstrate for the first time that decreased expression of an important signaling molecule (Alk8) in tooth development may contribute to the observed fluorotic phenotype, and that increased cell apoptosis may also play a role in the mechanism of fluorosis.

PMID: 16109993 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16154368&query_hl=19
Vet J. 2005 Sep 8; [Epub ahead of print]

Pharmacology of the Fluoroquinolones: A perspective for the use in domestic animals.

Martinez M, McDermott P, Walker R.

US Food and Drug Administration, Center for Veterinary Medicine, Office of New Animal Drug Evaluation, Rockville, MD 20855, USA.

The fluoroquinolones are a class of compounds that comprise a large and expanding group of synthetic antimicrobial agents. Structurally, all fluoroquinolones contain a fluorine molecule at the 6-position of the basic quinolone nucleus. Despite the basic similarity in the core structure of these molecules, their physicochemical properties, pharmacokinetic characteristics and microbial activities can vary markedly across compounds. The first of the fluoroquinolones approved for use in animals, enrofloxacin, was approved in the late 1980s. Since then, five other fluoroquinolones have been marketed for use in animals in the United States, with others currently under investigation. This review focuses on the use of fluoroquinolones within veterinary medicine, providing an overview of the structure-activity relationship of the various members of the group, the clinical uses of fluoroquinolones in veterinary medicine, their pharmacokinetics and potential interspecies differences, an overview of the current understanding of the pharmacokinetic/pharmacodynamic relationships associated with fluoroquinolones, a summary of toxicities that have been associated with this class of compounds, their use in both in human and veterinary species, mechanisms associated with the development of microbial resistance to the fluoroquinolones, and a discussion of fluoroquinolone dose optimization. Although the review contains a large body of basic research information, it is intended that the contents of this review have relevance to both the research scientist and the veterinary medical practitioner.

PMID: 16154368 [PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16098643&query_hl=3
J Environ Radioact. 2005 Aug 9; [Epub ahead of print]

Natural radioactivity in Brazilian groundwater.

Godoy JM, Godoy ML.

Instituto de Radioprotecao e Dosimetria, Comissao Nacional de Energia Nuclear, Avenida Salvador Allende s/n, Recreio dos Bandeirantes, CEP 22780-160 Rio de Janeiro, RJ, Brazil; Departamento de Quimica, Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente 225, Gavea, CEP 22543-900 Rio de Janeiro, RJ, Brazil.

More than 220 groundwater samples were analyzed for (228)Ra, (226)Ra, (222)Rn, (210)Pb, U(nat), Th(nat), pH, conductivity, fluoride and some additional elements determined by ICP-MS. Since samples from several Brazilian states were taken, involving areas with quite different geologies, no general trend was observed relating the chemical composition and the natural radionuclide content. On the other hand, (210)Pb strongly depends on the water content of its progenitor, (222)Rn. The values obtained during the present work were compared with those reported by Hainberger et al. [Hainberger, P.L., de Oliveira Paiva, I.R., Salles Andrade, H.A., Zundel, G., Cullen, T.L., 1974. Radioactivity in Brazilian mineral waters. Radiation Data and Reports, 483-488.], when more than 270 groundwater samples were analyzed, mainly, for (226)Ra. Based on the results of both works, it was possible to build a database including the results of both works, generating a set with the radium content of circa 350 groundwater sources. It was demonstrated that (228)Ra, (226)Ra, (222)Rn, (210)Pb and U(nat) content in Brazilian groundwater follows a lognormal distribution and the obtained geometric mean were 0.045, 0.014, 57.7, 0.040BqL(-1) and 1.2mugL(-1), respectively.

PMID: 16098643 [PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16128790&query_hl=9

Community Dent Oral Epidemiol. 2005 Oct;33(5):317-25.

Fluoride exposure from ingested toothpaste in 4-5-year-old Malaysian children.

Siew Tan B, Razak IA.

Stomatology Unit, Institute for Medical Research, Jalan Pahang, Kuala Lumpur, Malaysia. bsiew_tan@yahoo.com

OBJECTIVE: The aim of this study was to assess (by direct determination) the fluoride (F) exposure from ingested toothpaste among 4-5-year-old Malaysian children.
METHODS: This was part of a larger study to determine fluorosis status and F exposures. A total of 1343 10-11-year-old subjects were sampled by two-stage systematic random sampling for assessment of fluorosis. Two hundred 4-5-year-old siblings of these index subjects were sub-sampled for determination of F exposures from ingested toothpastes and other sources. Estimations of F ingested from toothpaste (FI) was made by the method of difference between 'F in toothpaste taken for use' and the 'F in toothpaste used but not swallowed', by the duplicate technique under normal home conditions. F ions were determined with the combination selective ion electrode.
RESULTS: The subjects ingested 32.9% of the toothpaste placed on the brush. Fluoride exposure from ingested toothpaste was highly variable and the mean was 426.9 +/- 505.5 microg (SEM 38.9)/48 h, or 213.5 microg/day and 131.9 microg per brushing.
CONCLUSIONS: The amount of ingested fluoride (FI) per brushing in this study was the lowest of all studies reporting this parameter and was within the pea-size range of 125-250 microg. Because of the highly statistically significant correlations between the FI from toothpaste and the amount of toothpaste dispensed (Pearson's correlation coefficient 0.647, P = 0.000), parents should assume responsibility for placement of toothpaste and limit the amount of toothpaste used.

PMID: 16128790 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16126217&query_hl=9
J Colloid Interface Sci. 2005 Aug 26; [Epub ahead of print]

Defluoridation of drinking water using activated titanium rich bauxite.

Das N, Pattanaik P, Das R.

Applied Chemistry and Corrosion Division, National Metallurgical Laboratory (CSIR), Jamshedpur 831 007, India;

Department of Chemistry, North Orissa University, Takatpur, Baripada 757 003, India.

The potential of thermally activated titanium rich bauxite (TRB) for adsorptive removal of excess fluoride from drinking water was examined. Adsorption with respect to variation of pH, adsorbent dose, initial fluoride concentration, presence of interfering ions and heat treatment were investigated by batch equilibrium experiments. Thermal activation at moderate temperatures (300-450 degrees C) greatly increased the adsorption capacity of TRB. The rate of adsorption was rapid and maximum level was attained within 90 min. The uptake of fluoride increased with increasing pH, reached to a maximum at pH 5.5-6.5 and thereafter decreased. The adsorption kinetics was found to follow first order rate expression and the experimental equilibrium adsorption data fitted reasonably well to both Langmuir and Freundlich isotherm models. The presence of common interfering ions in drinking water did not greatly affect the uptake of fluoride from aqueous solution indicating F specific sorption behaviour of TRB. Nearly complete desorption of adsorbed fluoride from loaded bauxite was achieved by treating with aqueous solutions of pH 11.1 ([NaOH] 0.015 mol/dm(3)).

PMID: 16126217 [PubMed - as supplied by publisher]

Full Free Report at http://www.cdc.gov/mmwr/preview/mmwrhtml/ss5403a1.htm
MMWR Surveill Summ. 2005 Aug 26;54(3):1-43.

Surveillance for dental caries, dental sealants, tooth retention, edentulism, and enamel fluorosis--United States, 1988-1994 and 1999-2002.

Beltran-Aguilar ED, Barker LK, Canto MT, Dye BA, Gooch BF, Griffin SO, Hyman J, Jaramillo F, Kingman A, Nowjack-Raymer R, Selwitz RH, Wu T; Centers for Disease Control and Prevention (CDC).

Division of Oral Health, National Center for Chronic Disease Prevention and Health Promotion, CDC, USA.

PROBLEM/CONDITION: Dental caries is a common chronic disease that causes pain and disability across all age groups. If left untreated, dental caries can lead to pain and infection, tooth loss, and edentulism (total tooth loss). Dental sealants are effective in preventing dental caries in the occlusal (chewing) and other pitted and fissured surfaces of the teeth. Enamel fluorosis is a hypomineralization of enamel related to fluoride exposure during tooth formation (first 6 years for most permanent teeth). Exposure to fluoride throughout life is effective in preventing dental caries. This is the first CDC Surveillance Summary that addresses these conditions and practices.
REPORTING PERIOD: 1988-1994 and 1999-2002.
SYSTEM DESCRIPTION: The National Health and Nutrition Examination Survey (NHANES) is an ongoing survey of representative samples of the civilian, noninstitutionalized U.S. population aged >/=2 months in NHANES 1988-1994 and all ages during 1999-2002. The dental component gathered information on persons aged >/=2 years.
RESULTS: During 1999-2002, among children aged 2-11 years, 41% had dental caries in their primary teeth. Forty-two percent of children and adolescents aged 6-19 years and approximately 90% of adults had dental caries in their permanent teeth. Among children aged 6-19 years, 32% had received dental sealants. Adults aged >/=20 years retained a mean of 24 of 28 natural teeth and 8% were edentulous. Among persons aged 6-39 years, 23% had very mild or greater enamel fluorosis. Disparities were noticed across all age groups, among racial/ethnic groups, persons with lower education and income, and by smoking status. From 1988-1994 to 1999-2002, four trends were observed: 1) no change in the prevalence of dental caries in primary teeth among children aged 2-11 years, 2) a reduction in prevalence of caries in permanent teeth of up to 10 percentage points among persons aged 6-19 years and up to six percentage points among dentate adults aged >/=20 years, 3) an increase of 13 percentage points in dental sealants among persons aged 6-19 years, and 4) a six percentage point reduction in total tooth loss (edentulism) among persons aged >/=60 years.
INTERPRETATION: The findings of this report indicate that the dental caries status of permanent teeth has improved since the 1988-1994 survey. Despite the decrease in caries prevalence and severity in the permanent dentition and the increase in the proportion of children and adolescents who benefit from dental sealants, disparities remain.
PUBLIC HEALTH ACTION: These data provide information for public health professionals in designing interventions to improve oral health and to reduce disparities in oral health, for researchers in assessing factors associated with disparities and dental caries in primary teeth, and in designing timely surveillance tools to monitor total fluoride exposure.

PMID: 16121123 [PubMed - indexed for MEDLINE]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16119654&query_hl=3
Rocz Akad Med Bialymst. 2005;50 Suppl 1:160-2.

Effect of fluoride preparations on the activity of human salivary cathepsin C.

Dabrowska E, Letko M, Roszkowska-Jakimiec W, Letko R, Jamiolkowski J.

Department of Social and Preventive Dentistry, Medical University of Bialystok, Poland. helpdentamb@tlen.pl

Preparations containing organic and inorganic fluorine compounds are used for oral hygiene. Fluoride ions contained in these preparations display high bioactivity and can alter the environment of the mouth. The aim of the study was to determine the effect of preparations containing aminofluorides, commonly used in oral hygiene, on the activity of salivary cathepsin C (EC 3.4.14.1). The research material included mixed saliva, collected at rest before and after the application of the following preparations: Elmex gelee, Elmex red fluid, Elmex green fluid, Fluormex rinse. The salivary pH, concentration of fluoride ions and activity of cathepsin C were determined. Fluoride preparations inhibit the activity of cathepsin C and cause changes in human salivary pH. Saliva can serve as a diagnostic material in the examination of the environmental exposure to fluorides.

PMID: 16119654 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16119021&query_hl=3
SADJ. 2005 Jul;60(6):238-40.

A comparison of results of fluoride determinations by different laboratories.

Mthethwa MT, du Plessis JB.

Dip Dental Hygiene, Swaziland Institute of Health Sciences.

With water fluoridation imminent in South Africa, the accurate determination of the fluoride content of water is important. The aim of this study was to compare the fluoride content of water reported by 9 laboratories and the laboratory at the South African Bureau of Standards (SABS). The SABS and 9 South African laboratories were asked to determine the fluoride content of five water samples. The fluoride content of the samples was in a range that could be expected in South African waters. The laboratories were requested to disclose their methods for fluoride determination. The results reported by the laboratories were compared to the results reported by the SABS laboratory. Fluoride concentrations of 0.13, 0.22 and 0.58 mg/litre were reproduced to within 0.05 mg/litre by two, six and three laboratories respectively. At the 1.1 and 1.5 mg/litre concentration no laboratory could achieve this accuracy. Four different methods for the determination of fluoride were used. At present laboratories determining fluoride concentrations are not accurate enough to ensure that the process of water fluoridation will be safe. Laboratories will have to check their procedures to ensure better results before water fluoridation can commence.

PMID: 16119021 [PubMed - indexed for MEDLINE]

Nuclear Physics A; Volume 758 , 25 July 2005, Pages 324-327
Nuclei in the Cosmos VIII
The Evolution of Fluorine in Galactic Systems

A. Rendaa (a), Y. Fenner (a), B.K. Gibson (a), A.I. Karakas (b), J.C. Lattanzio (c), S. Campbell (c), A. Chieffi (a,c,d,e), K. Cunha (f) and V.V. Smith (g)

(a) Centre for Astrophysics & Supercomputing, Swinburne University, Hawthorn, Victoria, 3122, Australia
(b) Institute for Computational Astrophysics, Department of Astronomy & Physics, Saint Mary's University, Halifax, Nova Scotia B3H 3C3, Canada
(c) Centre for Stellar & Planetary Astrophysics, School of Mathematical Sciences, Monash University, Clayton, Victoria 3800, Australia
(d) Istituto di Astrofisica Spaziale e Fisica Cosmica (CNR), Via Fosso del Cavaliere, 00133 Roma, Italia
(e) INAF Osservatorio Astronomico di Roma, Via Frascati 33, 00040 Monteporzio Catone, Italia
(f) Observatório Nacional, Rua General José Cristino 77, 20921 400 São Cristovão, Rio de Janeiro, Brazil
(g) Department of Physics, University of Texas at El Paso, El Paso, TX 79968, U.S.A.

The main astrophysical factories of fluorine (19F) are thought to be Type II supernovae, Wolf–Rayet stars, and the asymptotic giant branch (AGB) of intermediate mass stars. We present a model for the chemical evolution of fluorine in the Milky Way using a semi-analytic multi-zone chemical evolution model. For the first time, we demonstrate quantitatively the impact of fluorine nucleosynthesis in Wolf–Rayet and AGB stars. The inclusion of these latter two fluorine production sites provides a possible solution to the long-standing discrepancy between model predictions and the fluorine abundances observed in Milky Way giants. Finally, fluorine is discussed as a possible probe of the role of supernovae and intermediate mass stars in the chemical evolution history of the globular cluster ? Centauri.

Journal of Fluorine Chemistry - Article in Press, Corrected Proof -
Book review

Fluorine in Organic Chemistry’ by Richard D. Chambers FRS,
Foreword by George A. Olah.,
Blackwell Publishing, CRC Press, 2004, ISBN 104051-0787-1.

D. O’Hagan,

University of St Andrews, School of Chemistry and Centre for Biomolecular Science, Purdie Building, North Haugh, St Andrews, Fife KY16 9ST, UK

This is the second, and a substantially updated, edition of Dick Chambers’ classic book ‘Fluorine in Organic chemistry’. The first edition, published in 1973, has had two reprintings, and is recognised as a key text which provided a commentary on the interface of organofluorine chemistry with developing mechanistic theory in organic chemistry. This was important because the extreme properties of fluorine have tended to insulate it as a discipline from the mainstream, and the book, as well as Chambers general approach to organic fluorine chemistry, has been an important influence in maintaining contact with the mother discipline. As George Olah indicates in his Foreword, Fluorine in Organic Chemistry became a classic of the field and in the intervening three decades the field has grown enormously, not in small measure due to the contribution of the author and his colleagues.
The new edition has been updated significantly and although it holds to the original format, it is essentially a new book. It opens with a general introduction on the impact of organic fluorine chemistry in the materials, pharmaceuticals and agrochemical arenas as well as some of the basic properties of organic bound fluorine. There are early chapters on the preparation of highly fluorinated compounds by Halex type reactions moving towards recent developments in direct fluorination technology (e.g. micro-reactors). Partial or selective fluorination methods are reviewed with key reagents. Then follows a chapter dealing with the influence of fluorine substituents on reactivity and a systematic discussion on the stability of carbocations, radicals and anions. This begins the mechanistic discourse and then the discussion moves on to nucleophilic displacement from, and elimination reactions of, organo-fluorine compounds. Two substantial chapters (7 and 8) follow on the chemistry and behaviour of polyfluorinated organics and in particular the rich chemistry of small ring perfluorocyclics (e.g. cyclobut-ane/ene) an area Chambers has contributed significant literature to in his research programme. Then opens up a chapter on the synthesis and chemistry of fluoroaromatic and heteroaromatic compounds with an emphasis on the reactivity (nucleophilic and radical addition) of highly fluorinated systems. The book closes with a chapter on organometallic compounds in fluorine chemistry. This is a vast field but the emphasis is placed on systems and issues of particular synthetic interest to the organic chemist rather than, for example, the influence of fluorine on the nature of metal bonding within such complexes. Accordingly, the synthesis and reactivity of RfM (Li, Mg, Zn, Hg, B, Al, Si, Sn, Cu, etc.) complexes are reviewed. These chapters are supported by a distillation and ordering of an extensive literature drawing up to 2000 references. However, the book is not encyclopaedic (406 pp.); it is concise and eminently readable and it is a scholarly contribution at the highest level. The first edition has been a constant companion for many of us involved in organo-fluorine research and it is pleasing to have this new one emerge.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16026511&query_hl=1
Clin Exp Pharmacol Physiol. 2005 Jul;32(7):531-5.

Effects of tail fat on halothane biotransformation in fat-tailed sheep.

Sharifi S, Vesal N.

Department of Veterinary Clinical Science, School of Veterinary Medicine, Shiraz University, Shiraz, Iran.

1. The aim of the present study was to evaluate the effects of tail fat on halothane biotransformation following similar anaesthetic exposure in intact sheep and sheep with a ligated median sacral artery.
2. A prospective randomized experimental study was performed using 12 healthy, 10-12-month-old female sheep.
3. Sheep were randomly divided into two groups of six animals each and were anaesthetized twice at 2 weekly intervals. After mask induction with halothane in 100% oxygen, sheep were intubated and anaesthesia was maintained for 3 h using a rebreathing system. Serum fluoride concentration (SFC) was measured at 0, 1, 3, 6, 12, 24, 48 and 72 h following the induction of anaesthesia. Serum biochemistry was also evaluated at baseline and 72 h after anaesthesia. Induction and extubation times and time to sternal recumbency were also recorded during anaesthetic induction and recovery. Prior to the second anaesthesia (2 weeks later), the median sacral artery (MSA) was ligated under epidural anaesthesia in the experimental group. Sheep in the control group underwent sham operation. All sheep were anaesthetized as before.
4. Following the first halothane anaesthesia, SFC was significantly increased from 3 to 48 h compared with baseline. In the second stage of the experiment, the increases in SFC in the control group were similar to those seen in the first stage of the experiment. However, in MSA-ligated sheep, the increases in SFC were only significant between 3 and 12 h compared with baseline. The SFC was significantly higher in intact sheep from 3 to 72 h compared with the MSA-ligated group. Extubation and sternal recumbency times were significantly longer in intact sheep.
5. Ligation of the MSA in fat-tailed sheep induced a significant reduction in SFC, suggesting that the presence of tail fat substantially affects halothane metabolism during the peri-anaesthetic period in sheep. The greater extent of halothane biotransformation may be clinically important in, otherwise normal, obese patients.

Microchemical Journal Volume 81, Issue 1 , August 2005, Pages 19-22

Determination of fluoride in drinking water and in urine of adolescents living in three counties in Northern Chihuahua Mexico using a fluoride ion selective electrode
Alma Ruiz-Payan (a), Melchor Ortiz (b) and Maria Duarte-Gardea (c)

a - Environmental Science and Engineering Ph.D. Program, El Paso, TX 79902, United States
b - School of Public Health, University of Texas-Houston Health Sciences Center, El Paso, TX 79902, United States
c - Department of Health Promotion, University of Texas at El Paso, El Paso, TX 79902, United States

This study was carried out to determine fluoride in drinking water and in urine of adolescents, ages 15–20 years, living in Northern Chihuahua Mexico. Participants are from a cross-sectional study on health effects of chronic fluoride exposure from drinking water. A total of 201 participants (106 female and 95 male) in the study were recruited from three counties. Samples of drinking water of each county were collected and analyzed using the U.S. EPA Fluoride Ion-Selective Method. Statistically significant difference of fluoride content in water was found among the three counties of recruitment (Cd. Juarez; 0.3 mg/L, Samalayuca, 1.0 mg/L, and Villa Ahumada, 5.3 mg/L). Fluoride content in wells and tap water samples of Villa Ahumada ranged from 5.0 to 5.7 mg/L. Fluoride content of these samples was above the level permitted by Mexican regulations. The fluoride content in bottled water obtained from local stores in Villa Ahumada ranged from 0.3 to 3.7 mg/l.
Fluoride in urine samples of each participant was also analyzed using the U.S. EPA Ion-Selective Method. The mean fluoride urine concentration (reported in mg/g creatinine) in adolescents living in these counties was 0.792±0.39, 1.33±0.67 and 2.22±1.16 (Cd. Juarez, Samalayuca and Villa Ahumada), respectively. The high fluoride urinary levels found in participants from Villa Ahumada may be associated to the high fluoride level (5.3 mg/L) in dinking water.
The accuracy of measurements was assessed with reference materials in water and in urine. Mean fluoride recovery was 99.0% and 99.6% in water and in urine, respectively. The levels obtained were within the assayed 5% confidence levels.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15905927&query_hl=2
(includes Link to full free report)
Cad Saude Publica. 2005 Mar-Apr;21(2):652-5. Epub 2005 Mar 21.

[Dental fluorosis in schoolchildren in a county in the mountainous region of Rio Grande do Sul State, Brazil]

[Article in Portuguese]

Toassi RF, Abegg C.

Faculdade de Odontologia, Universidade do Planalto Catarinense, Lages, Brazil. ramonafernanda@zipmail.com.br

The aim of the present study was to determine the prevalence and severity of dental fluorosis in all schoolchildren (ages 4 to 18 years, n = 259) from the town of Santa Tereza, Rio Grande do Sul, Brazil, and to investigate associated factors. Data were obtained through a questionnaire and by means of clinical tests. Dean's index was used to determine fluorosis occurrence. Prevalence of fluorosis was 63.7%. The predominant category was very mild (43.6%), followed by mild (12.0%), moderate (7.7%), borderline (7.3%), and severe (0.4%). Approximately 85.0% of the schoolchildren currently have, or have had, access to other topical sources of fluoride. Significant associations were found between place of residence and previous or ongoing fluoride mouth rinsing and prevalence and severity of fluorosis (p < 0.05). There was also a significant association between dental fluorosis and parents' level of schooling, frequency of brushing teeth, fluoride rinsing, and use of fluoride gel (p < 0.05).

PMID: 15905927 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15877161&query_hl=1
J Environ Monit. 2005 May;7(5):419-24. Epub 2005 Apr 18.

Characterization of individual aerosol particles in workroom air of aluminium smelter potrooms.

Hoflich BL, Weinbruch S, Theissmann R, Gorzawski H, Ebert M, Ortner HM, Skogstad A, Ellingsen DG, Drablos PA, Thomassen Y.

Institute of Applied Geosciences, Technical University of Darmstadt, Schnittspahnstr. 9, D-64287 Darmstadt, Germany.

Aerosol particles with aerodynamic diameters between 0.18 and 10 [micro sign]m were collected in the workroom air of two aluminium smelter potrooms with different production processes (Soderberg and Prebake processes). Size, morphology and chemical composition of more than 2000 individual particles were determined by high resolution scanning electron microscopy and energy-dispersive X-ray microanalysis. Based on chemical composition and morphology, particles were classified into different groups. Particle groups with a relative abundance above 1%(by number) include aluminium oxides, cryolite, aluminium oxides-cryolite mixtures, soot, silicates and sea salt. In both production halls, mixtures of aluminium oxides and cryolite are the dominant particle group. Many particles have fluoride-containing surface coatings or show agglomerations of nanometer-sized fluoride-containing particles on their surface. The phase composition of approximately 100 particles was studied by transmission electron microscopy. According to selected area electron diffraction, sodium [small beta]-alumina (NaAl(11)O(17)) is the dominant aluminium oxide and cryolite (Na(3)AlF(6)) the only sodium aluminium fluoride present. Implications of our findings for assessment of adverse health effects are discussed.

PMID: 15877161 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15859115
Environ Sci Pollut Res Int. 2005;12(2):89-95.

Natural pollution caused by the extremely acidic crater lake Kawah Ijen, East Java, Indonesia.

Lohr AJ, Bogaard TA, Heikens A, Hendriks MR, Sumarti S, Van Bergen MJ, Van Gestel CA, Van Straalen NM, Vroon PZ, Widianarko B.

Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, NL-1081 HV Amsterdam, The Netherlands. ansje.lohr@ecology.falw.vu.nl

BACKGROUND, AIMS AND SCOPE: Lakes developing in volcano craters can become highly acidic through the influx of volcanic gases, yielding one of the chemically most extreme natural environments on earth. The Kawah Ijen crater lake in East Java (Indonesia) has a pH < 0.3. It is the source of the extremely acidic and metal-polluted river Banyupahit (45 km). The lake has a significant impact on the river ecosystem as well as on a densely populated area downstream, where agricultural fields are irrigated with water with a pH between 2.5 and 3.5. The chemistry of the river water seemed to have changed over the past decade and the negative effect in the irrigation area increased. A multidisciplinary approach was used to investigate the altered situation and to get insight in the water chemistry and the hydrological processes influencing these alterations. Moreover, a first investigation of the effects of the low pH on ecosystem health and human health was performed.
METHODS: Water samples were taken at different sites along the river and in the irrigation area. Sampling for macroinvertebrates was performed at the same sites. Samples of soil and crop were taken in the irrigation area. All samples were analysed for metals (using ICP-AES) and other elements, and concentrations were compared to local and international standards.
RESULTS AND DISCUSSION: The river carries a very high load of SO4, NH4, PO4, Cl, F, Fe, Cu, Pb, Zn, Al and other potentially toxic elements. Precipitation and discharge data over the period of 1980-2000 clearly show that the precipitation on the Ijen plateau influences water chemistry of the downstream river. Metal concentrations in the river water exceed the concentrations mentioned in Indonesian and international quality guidelines, even in the downstream river and the irrigation area. Some metal concentrations are extremely high, especially iron (up to 1,600 mg/l) and aluminium (up to 3,000 mg/l). The food-webs in the acidic parts of the river are highly underdeveloped. No invertebrates were present in the extremely acidic water and, at pH 2.3, only chironomids were found. This also holds true for the river water with pH 3.3 in the downstream area. Agricultural soils in the irrigation area have a pH of 3.9 compared to a pH of 7.0 for soils irrigated with neutral water. Decreased yields of cultivated crops are probably caused by the use of Al containing acidic irrigation water. Increased levels of metals (especially Cd, Co, Ni and Mn) are found in different foodstuffs, but still remain within acceptable ranges. Considering local residents' diets, Cd levels may lead to an increased risk for the human health. Fluoride exposure is of highest concern, with levels in drinking water exceeding guideline values and a lot of local residents suffering from dental fluorosis.
CONCLUSIONS, RECOMMENDATIONS AND OUTLOOK: In short, our data indicate that the Ijen crater lake presents a serious threat to the environment as well as human health and agricultural production.

PMID: 15859115 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15859399
Huan Jing Ke Xue. 2005 Jan;26(1):7-11.

[Content and distribution of fluorine in Chinese coals]

[Article in Chinese]

Wu DS, Zheng BS, Tang XY, Wang Y, Liu XJ, Hu J, Finkelman RB.

State Key Lab of Environmental Geochemistry, Institute of Geochemistry, CAS, Guiyang 550002, China. wudaishe@hotmail.com

Nationwide sampling program is designed according to the resources distribution and coal-forming periods as well as coal rank and yield of coal in China, and 305 coal samples were collected from 26 provinces, municipalities and autonomous regions. Fluorine in coal is determined by pyrohydrolysis / fluoride-ion selective electrode method. Fluorine in coals is mainly of an inorganic nature. Coal rank has no effect on fluorine content. The influence of a factor, such as geological age, on fluorine contents might be concealed by other factors, more research should be done to discern it. The distribution of fluorine in each province, municipality and autonomous region's coals is studied, and the fluorine source in coal-burning endemic fluorosis areas should be estimated over again. The contents of fluorine in Chinese coals show logarithm normal distribution, and 90% of values ranged from 47mg/kg to 347mg/kg, the average fluorine content in Chinese coals was designated as the geometric mean, 136mg/kg. Fluorine in Chinese coals is within the world coal's range.

PMID: 15859399 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15859400
Huan Jing Ke Xue. 2005 Jan;26(1):12-5.

[Emission of fluorine from black liquor coal-water slurry combustion]

[Article in Chinese]

Ren Q, Liu JZ, Sheng JJ, Ye L, Cao XY, Zhou JH, Cen KF.

Clean Energy and Environment Engineering Key Laboratory of Ministry of Education, Zhejiang University, Hangzhou 310027, China.

The paper is about the emission of fluorine from an experimental boiler of 0.25 MW when burning black liquor coal-water slurry (CWS). The result is compared with CWS. And the analysis of effect factors is also carried out. Experimental research show that, the content of fluorine in CWS, which was less than 30 mg/kg, was relatively low. The emission ratio and concentration of fluorine were 70% - 90% and 2.0 - 2.6 mg/m3 respectively when burning common CWS; while the data of those when combusting black liquor CWS were 45% - 80% and 1.7 - 3.0 mg/m3 respectively. The hearth temperature and the element of CWS were two factors of emission fluorine when burning CWS.

PMID: 15859400 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15798897
Osteoporos Int. 2005 Mar 30; [Epub ahead of print]

Assessment of teeth as biomarkers for skeletal fluoride exposure.

Vieira AP, Mousny M, Maia R, Hancock R, Everett ET, Grynpas MD.

Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.

Skeletal fluorosis and dental fluorosis are diseases related to fluoride (F) ingestion. Bone is the largest storage site of F in our body. Therefore, bone F concentrations are considered biomarkers for total F body burden (exposure). However, difficult accessibility limits its use as a biomarker. Thus, a more accessible tissue should be considered and analyzed as a biomarker for total F body burden. The objective of this study, which was divided into two parts, was to evaluate teeth as a biomarker for skeletal F exposure. In part 1 of the study, 70 mice of three different strains (SWR/J, A/J and 129P3/J) were exposed to different levels of water fluoridation (0, 25, 50 and 100 ppm). Bone (femora and vertebrae) and teeth from these mice were then analyzed for F concentration using Instrumental Neutron Activation Analysis (INAA). In part 2 of the study, human teeth (enamel and dentin) and bone from 30 study subjects were collected and analyzed for F concentration using INAA. Study subjects lived in areas with optimum levels of water fluoridation (0.7 and 1 ppm) and underwent therapeutic extraction of their unerupted third molars. The values of bone and teeth F concentration were correlated for parts 1 and 2 of this study. The results showed that in the animal model, where animals were exposed to a wide range of F in their drinking water, tooth [F] correlated with bone [F]. However, no correlation was seen between bone and enamel F concentrations or between bone and dentin F concentrations in the human samples. Therefore, teeth are not good biomarkers for skeletal F exposure in humans when exposure is confined to optimum levels of F in the drinking water.

PMID: 15798897 [PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15841963
Bull Environ Contam Toxicol. 2005 Feb;74(2):242-9.

Toxicity of fluoride to the endangered unionid mussel, Alasmidonta raveneliana, and surrogate species.

Keller AE, Augspurger T.

USEPA, 701 San Marco Boulevard, Suite 7W, Jacksonville, FL 32207, USA.

The Appalachian elktoe, Alasmidonta raveneliana, is a federally-listed endangered unionid mussel whose range once included the Cumberland and Tennessee River drainages, but is now limited to the Tennessee River and its tributaries, Nolichucky River system, Pigeon River system, Mills River, and Little River (Burch 1975, USFWS 1996, Bogan 2002). The decline in abundance of this species and other unionids is believed to have resulted from habitat destruction, competition with nonindigenous species, the loss of host fish species that are necessary for larval transformation to the juvenile stage, and contamination (Williams et al. 1993, USFWS 1994, The Nature Conservancy 1992). One of the healthiest remaining populations of the Appalachian elktoe mussel is found in North Carolina's North Toe River that now receives discharges from feldspar mining operations containing significant concentrations of fluoride. Fluoride is known to be toxic to fish, zooplankton, aquatic insects and some adult unionid mussels (Smith et al. 1985, Feiser 1986, Camargo and Tarazona 1990, Muley 1990). However, no fluoride toxicity data were available for early life stages of the endangered A. raveneliana. The present study was conducted primarily as a means of evaluating fluoride as a possible limiting factor in the recovery of this mussel species. A second goal was to test several fish species as potential hosts for the mussel larvae during transformation.

Excerpts:

... Two juvenile tests were conducted for nine days (216 hr) resulting in little decrease in LC50S, i.e., A. raveneliana, LC50 of 223 mg/L F and L. fasciola, LC50 of 177 mg/L F, compared to those determined at 96 hr (Table 1). However, based on an ANOVA and Duncan's test, there were significant differences (p≤0.05) in growth (based on shell lengths) between controls and juvenile mussels exposed to fluoride (Table 3). Control mussels had a mean shell length (± s.d.) of )0.362±0.019 mm, while mussels exposed to fluoride had mean lengths of 0.348±0.027 mm, 0.333±0.022 mm and 0.318±0.021 mm, for 31, 62 and 124 mg/L F, respectively. Using these results, the acute to chronic ratio (96 hr LC50 divided by the geometric mean of the chronic No Observed Effect Concentration [NOAEC] and Lowest Observed Adverse Effect Concentration [LOAEC], USEPA (1985) for F in these mussels is at least 10. Note that no NOAEC other than zero was defined.

... Sublethal effects occurred at concentrations as low as one-tenth of the 96 hr LC50S, and one-fifth of the 9-d LC 50S. Few studies have evaluated growth impacts in juvenile unionids resulting from short-term exposure to pollutants. The success of the current study is therefore of particular value. Results of the 9-days tests indicated that subchronic exposures of juvenile mussels to fluoride can impair their growth at 31 mg F/L, but this concentration is about 17 times that permitted by the State of North Carolina. Facilities are generally meeting this standard; the ambient concentration of fluoride in the North Toe River at Penland, NC (which is within a mile downstream of four of the five mine discharges) ranged from <0.1 to 3.0 mg/L F with a median of 0.87 mg F/L over the past decade. These concentrations are significantly higher than those from the North Toe River ambient monitoring station near Ingalls, NC (upstream of all five facilities) which ranged from <0.1 to 2.0 mg/L F with a median of 0.2 mg F/L over the past decade, but they are still well below the sublethal effects concentrations determined in this study. Because growth impacts were measurable after such a short time in this study and mussels live for decades, it would be worthwhile to perform more lengthy exposures at lower concentrations. Smaller adults are known to suffer greater predation effects and reduced reproductive success compared to those of normal size and this could have a negative impact on populations in the long term.

PMID: 15841963 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15776095
N Z Med J. 2005 Feb 25;118(1210):U1319.

Effect of volcanic gas exposure on urine, blood, and serum chemistry.

Durand M, Florkowsk C, George P, Walmsley T, Weinstein P.

Natural Hazards Research Centre, Department of Geological Sciences, University of Canterbury, Christchurch, New Zealand. michaeldurand2004@yahoo.co.uk

AIMS: This pilot study tested the hypothesis that aluminium (Al), rubidium (Rb), arsenic (As), lead (Pb), mercury (Hg), fluorine (F), and chlorine (Cl), which are all known to be present in volcanic emissions, may be useful biological markers for occupational gas exposure in volcanologists.
METHODS: Ten human subjects were exposed to fumarole gases on White Island, New Zealand, for approximately 20 minutes. Sulphur dioxide (SO2) exposure was recorded by personal monitoring tubes. Pre- and post-exposure urine, blood and serum samples (collected using standard protocols) were analysed in the pathology laboratory for trace element and halogen content.
RESULTS: Average personal exposure was measured at <75 ppm SO2 and calculated at approximately 25 ppm HCl, approximately 8 ppm hydrogen fluoride (HF), approximately 1 ppm Al, approximately 0.1 ppb Rb and approximately 4 ppb Pb. These concentrations almost certainly exceed those usually found in occupational exposure settings. Advanced levels of urinary Al and Rb were found following gas exposure and were statistically significant in the population at p<0.005 and p<0.001, respectively. The other chemical elements that were analysed (urinary Cl, F, and Hg; blood Pb, and serum Al) did not show such patterns.
CONCLUSIONS: It is possible that urinary Al and Rb may be useful markers for exposure, a hypothesis which should be followed up in future work.

PMID: 15776095 [PubMed - in process]

From Science Direct
Science of The Total Environment - 2005. Article in Press, Corrected Proof. Available online 29 January 2005.

The impact of the hyperacid Ijen Crater Lake: risks of excess fluoride to human health

Alex Heikens(a), Sri Sumarti (b, c), Manfred van Bergen (b), Budi Widianarko (d), Luuk Fokkert (e), Kees van Leeuwen (f) and Willem Seinen (a)

a. Institute for Risk Assessment Sciences, Yalelaan 2, 3584 CM, The Netherlands
b. Faculty of Geosciences, University of Utrecht, Budapestlaan 4, 3584 CD Utrecht, The Netherlands
c. Volcanology and Geological Hazard Mitigation, Jalan Cendana 15, Yogyakarta, Indonesia
d. Soegijapranata Catholic University, Jl. Pawiyatan Luhur IV/I, Bendang Duwur, Semarang 50234, Indonesia
e. National Institute of Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, 3721 MA, Bilthoven, The Netherlands
f. European Commission, Joint Research Institute, Via E. Fermi 1, I-21020 Ispra (VA), Italy

The Asembagus irrigation area (East Java, Indonesia) receives a high input of fluoride (F) via surface water that partially originates from the hyperacid crater lake of the Ijen volcano. Endemic dental fluorosis among local residents has been ascribed to F in water wells. In this study, the total F intake by children and adults was estimated, based on concentrations in well waters and foods throughout the area. These values were compared with the Lowest Observed Adverse Effect Level (LOAEL) for dental fluorosis among children and skeletal fluorosis among adults. Fluorosis hazard maps were prepared, identifying the most hazardous locations in the area. It was concluded that there is not only a high risk of dental fluorosis, but also of skeletal fluorosis. Based on the total daily intake, the lowest F concentration in drinking water that poses a risk of developing fluorosis is approximately 0.5 mg/l for dental fluorosis and 1.1 mg/l for skeletal fluorosis. This is below 1.5 mg/l, which is both the guideline value for drinking water from the World Health Organization (WHO) and the Indonesian drinking water standard. This is the first documented case of human health problems that may be directly associated with natural pollutants originating from a volcano-hosted crater lake.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15693498
J Am Dent Assoc. 2005 Jan;136(1):67-70.

Controlling the fluoride dosage in a patient with compromised salivary function.

Eichmiller FC, Eidelman N, Carey CM.

American Dental Association Foundation, Paffenbarger Research Center, National Institute of Standards and Technology, Gaithersburg, MD 20899-8546, USA. Frederick.Eichmiller@nist.gov

BACKGROUND: High-concentration topical fluorides are used commonly to with compromised salivary function due to irradiation and chemotherapy.
CASE DESCRIPTION: The authors describe a 50-year-old man with previously treated cancer who was using tray-applied topical fluoride gel. He complained of gastric symptoms, difficulty in swallowing, leg muscle soreness and knee joint soreness. A computed tomographic scan revealed thickening of the esophageal walls. An upper endoscopy revealed abnormal motility. The motility test indicated high-amplitude peristalsis and hypertensive lower esophageal sphincter, and urine testing indicated high levels of systemic fluoride. The patient's fluoride regimen was altered, and within a short period his urinary fluoride levels returned to normal and his symptoms resolved.
CLINICAL IMPLICATIONS: Clinicians prescribing home-applied high-concentration fluorides need to be cognizant of the symptoms of fluoride toxicity, carefully monitor the patient's compliance with the treatment regimen, and adjust the dosage or mode of application to control the total ingested dose of fluoride.

PMID: 15693498 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15740709
Arch Oral Biol. 2005 Mar;50(3):309-16.

Estimation of fluoride distribution in the mandible and teeth of the red deer (Cervus elaphus L.) from industrially polluted areas in Poland.

Zakrzewska H, Machoy-Mokrzynska A, Materny M, Gutowska I, Machoy Z.

Department of Biochemistry, Agriculture Academy, Szczecin, Poland.

MINI SUMMARY: Animals from areas contaminated by industrial emissions containing fluoride may accumulate it predominantly in hard tissues. Therefore, an analysis was performed for the determination of fluoride content in mandibles and teeth of deer living at large in different areas in Western Pomerania (Poland). Samples of hard tissues obtained with a dental drill, were dissolved in perchloric acid and analyzed for fluoride content with an ion-selective electrode. Using the Generalized Regression Neural Network (GRNN), it was possible to arrange definite variables according to their order of importance concerning the fluoride mean content in investigated bone material. Parametric analysis revealed in which sites of mandibles and teeth the fluoride accumulation was the highest. In our calculation, the traditional statistic as well as artificial neural network was applied.
OBJECTIVE: One of the interesting properties of fluoride is its balancing accumulation in the hard and soft tissues. In this paper, we decided estimate how the changeable doses of fluoride in natural environment influence on fluoride distribution and accumulation in the examined sites of mandible and teeth.
MATERIAL AND METHOD:: The material consist of 103 mandibles of red deer (Cervus elaphus L.) from five forestry districts of Western Pomerania in Poland, which are located near or far away from two major industrial plants: Police Chemical Work and the Dolna Odra Coal Power Plant. Samples (10 mg of powdered bone or tooth) were dissolved in perchloric acid and the fluoride content was determined with an ion-selective electrode. Comparisons were done with the Statistica 5.5 and Statistica Neural Networks.
RESULTS: Animals living in Western Pomerania (Poland) have high fluoride contents in their bones. Fluoride accumulation in mandibles and teeth is irregular. The higher content of fluoride show incisal area, but coronoid process of the mandible was not sensitive to different exposure of environmental fluoride at all. Parametric analysis revealed that the accumulation pattern of fluorine was different in the two groups of deer.
CONCLUSIONS: Many biological and environmental factors may influence on incessant fluoride accumulation in osseous tissue of ruminants living at large. The use of artificial neural networks enables a more accurate insight into the process of fluorine accumulation in the mandible and teeth and helps in the ranking of factors influencing this process.

PMID: 15740709 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15759914
Salud Publica Mex. 2005 Jan-Feb;47(1):58-63.

[Estimation of exposure to fluoride in "Los Altos de Jalisco", Mexico]

[Article in Spanish]

Hurtado-Jimenez R, Gardea-Torresdey J.

El Colegio de la Frontera Norte, A.C. Ciudad Juarez, Chihuahua, Mexico. rhurtado@colef.mx

OBJECTIVE: To estimate the level of fluoride exposure and human health risks in Los Altos de Jalisco (Jalisco State Heights) region.
MATERIAL AND METHODS: This study was conducted between May and July 2002. The fluoride concentrations of 105 water wells and six tap water samples were electrochemically measured. Exposure doses to fluoride and total intake of fluoride were estimated for babies (10 kg), children (20 kg), and adults (70 kg).
RESULTS: The fluoride concentration of the water samples ranged from 0.1 to 17.7 mg/l. More than 45% of the water samples exceeded the national guideline value for fluoride of 1.5 mg/l. The estimated values of the exposure doses to fluoride and total intake of fluoride were in the range of 0.04-1.8 mg/kg/d and 0.5-18.4 mg/d, respectively.
CONCLUSIONS: Dental fluorosis, skeletal fluorosis, and bone fractures are some of the potential health risks due to the intake of high doses of fluoride for the population of Los Altos de Jalisco. In order to reduce health risks, fluoridated salt, fluoridated toothpastes, and drinking water containing more than 0.7 mg/l of fluoride should be avoided.

PMID: 15759914 [PubMed - in process]

Fuel Volume 84, Issue 4 , March 2005, Pages 353-357

Volatilization behavior of fluorine in coal during fluidized-bed pyrolysis and CO2-gasification

Wen Li, , Hailiang Lu, Haokan Chen and Baoqing Li

State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan South Road No. 27, Taiyuan 030001, People's Republic of China

The volatilization behavior of fluorine in five Chinese coals was investigated during fluidized-bed pyrolysis and CO2-gasification at a temperature range of 500–900 °C. The effect of co-existed and added calcium on fluorine volatility during pyrolysis was also determined. With increasing pyrolysis temperature, the volatility of fluorine increases. However, the volatility is greatly dependent on the fluorine chemical forms occurred in coal. Except for Datong and Zhungeer coal, more than 65% of fluorine in other three coals occurs as the steady forms. Fluorapatite is not the major carrier of fluorine in the coals studied. Fluorine volatility is retarded by coexisting calcium during coal pyrolysis, indicating that at least part of the stable forms of fluorine in coal might occur as calcium fluoride or calcium fluoride with complex compounds which are stable even at high pyrolysis temperature. The addition of CaO and limestone can suppress the release of fluorine during pyrolysis. The effect of CaO is better than that of limestone. The volatility of fluorine of coal during CO2-gasification depends on not only the occurrence mode of fluorine, but also the gasification reactivity of the coal. Compared with N2 atmosphere, CO2 is more favorable to the release of fluorine from coal.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15750536
Am J Orthod Dentofacial Orthop. 2005 Feb;127(2):177-85.

Physical properties of root cementum: Part 4. Quantitative analysis of the mineral composition of human premolar cementum.

Rex T, Kharbanda OP, Petocz P, Darendeliler MA.

Discipline of Orthodontics, Faculty of Dentistry, University of Sydney, 2 Chalmers Street, Surry Hills NSW 2010, Australia.

BACKGROUND: The aim of this study was to perform a quantitative analysis of the calcium (Ca), phosphorus (P), and fluoride (F) concentrations in human first premolars.
METHODS: This study was conducted on 18 maxillary or mandibular first premolars that were collected from 16 prospective orthodontic patients (10 male, 6 female), mean age 13.9 years (range, 11.7-16.1 years), requiring first premolar extractions. After extraction, the teeth were prepared for electron probe microanalysis. The Ca, P, and F concentrations were measured on the buccal and lingual surfaces at the midpoint of the cervical, middle, and apical thirds of the root from the outer to middle to inner third of the cementum.
RESULTS AND CONCLUSIONS: In first premolar cementum, there was significant interindividual variation in the Ca, P, and F concentrations ( P = .024, .017, and .000, respectively). There was no significant difference in the Ca, P, and F concentrations of cementum between the buccal and lingual surfaces, except for a significantly higher F content at the cervical region on the buccal surface ( P = .000). There was a decreasing gradient in the Ca, P, and F concentrations from the cervical to the apical third of the root, which was highly significant from the cervical to middle third ( P = .000) and from the middle to apical third ( P = .000), except for F, for which there was no significant difference from the cervical to the middle third on the lingual surface ( P = .966). There was a significant increasing gradient in the Ca and P concentrations from the outer to inner third of cementum at the cervical ( P < .01) and middle ( P < .01) thirds of the root but no significant difference at the apical third of the root. For F, there was a significant decreasing gradient from the outer to the inner third of cementum at the cervical ( P < .01), middle ( P < .01) and apical ( P < .01) thirds of the root.

PMID: 15750536 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15748797
Regul Toxicol Pharmacol. 2005 Apr;41(3):228-39.

Toxicological profile of hydrofluoropolyethers

G. Malinvernoa, I. Colombob, , and M. Viscab

(a) Solvay S.A., European Public Affairs Brussels, Belgium
(b) Solvay Solexis R&D Centre, Regulatory Affairs and Industrial Toxicology, Bollate, Italy

Received 14 June 2004. Available online 20 January 2005.

Hydrofluoropolyethers (HFPE) are a family of linear oligomeric fluorinated fluids comprising a chain of difluoromethoxy and tetrafluoroethoxy repeating units with terminal OCF2H end groups, each of which contains an isolated hydrogen atom. These fluids have been designed as low environmental impact substitutes for perfluorinated organic substances in a number of applications including heat transfer and fire suppression agents, and as a solvent. The toxicological profile of these new fluids has been evaluated and is presented in this paper. Acute toxicity tests have been performed on Sprague–Dawley Crl: CD (SD) BR rats using oral, dermal, and inhalation routes. No deaths were recorded even at the highest tested concentrations, and the resultant LD50/LC50 values were >5000 mg/kg (oral), >2000 mg/kg (dermal), and >26,411 ppm (inhalation: reversible anaesthetic effects, e.g., lethargy, seen at this exposure concentration). Other short-term tests (skin and eye irritation, skin sensitisation, genotoxicity tests in vitro and in vivo, cardiac sensitisation) were also performed, and no hazardous properties were identified. Effects of repeated exposure by inhalation were examined in rats over test periods of 5, 14, 28, and 90 days. Effects on embryo–foetal development in the rat have also been studied. The 28-day, 90-day and developmental studies were performed using nominal HFPE concentrations of 1000, 3300, and 10,000 ppm (6 h/day: actual exposures confirmed by test atmosphere analysis), and the highest tested concentration proved to be an NOAEL in each study. Major observed effects were elevated urinary (inorganic) fluoride levels and increased liver weights with centrilobular hepatocyte hypertrophy (considered an adaptive response, linked to hepatic metabolism of absorbed material).

From Science Direct
Fuel Volume 84, Issue 4 , March 2005, Pages 353-357

Volatilization behavior of fluorine in coal during fluidized-bed pyrolysis and CO2-gasification

Wen Li, , Hailiang Lu, Haokan Chen and Baoqing Li

State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan South Road No. 27, Taiyuan 030001, People's Republic of China

The volatilization behavior of fluorine in five Chinese coals was investigated during fluidized-bed pyrolysis and CO2-gasification at a temperature range of 500–900 °C. The effect of co-existed and added calcium on fluorine volatility during pyrolysis was also determined. With increasing pyrolysis temperature, the volatility of fluorine increases. However, the volatility is greatly dependent on the fluorine chemical forms occurred in coal. Except for Datong and Zhungeer coal, more than 65% of fluorine in other three coals occurs as the steady forms. Fluorapatite is not the major carrier of fluorine in the coals studied. Fluorine volatility is retarded by coexisting calcium during coal pyrolysis, indicating that at least part of the stable forms of fluorine in coal might occur as calcium fluoride or calcium fluoride with complex compounds which are stable even at high pyrolysis temperature. The addition of CaO and limestone can suppress the release of fluorine during pyrolysis. The effect of CaO is better than that of limestone. The volatility of fluorine of coal during CO2-gasification depends on not only the occurrence mode of fluorine, but also the gasification reactivity of the coal. Compared with N2 atmosphere, CO2 is more favorable to the release of fluorine from coal.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15693498
J Am Dent Assoc. 2005 Jan;136(1):67-70.

Controlling the fluoride dosage in a patient with compromised salivary function.

Eichmiller FC, Eidelman N, Carey CM.

American Dental Association Foundation, Paffenbarger Research Center, National Institute of Standards and Technology, Gaithersburg, MD 20899-8546, USA. Frederick.Eichmiller@nist.gov

BACKGROUND: High-concentration topical fluorides are used commonly to with compromised salivary function due to irradiation and chemotherapy.
CASE DESCRIPTION: The authors describe a 50-year-old man with previously treated cancer who was using tray-applied topical fluoride gel. He complained of gastric symptoms, difficulty in swallowing, leg muscle soreness and knee joint soreness. A computed tomographic scan revealed thickening of the esophageal walls. An upper endoscopy revealed abnormal motility. The motility test indicated high-amplitude peristalsis and hypertensive lower esophageal sphincter, and urine testing indicated high levels of systemic fluoride. The patient's fluoride regimen was altered, and within a short period his urinary fluoride levels returned to normal and his symptoms resolved.
CLINICAL IMPLICATIONS: Clinicians prescribing home-applied high-concentration fluorides need to be cognizant of the symptoms of fluoride toxicity, carefully monitor the patient's compliance with the treatment regimen, and adjust the dosage or mode of application to control the total ingested dose of fluoride.

PMID: 15693498 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15688330
J Perianesth Nurs. 2005 Feb;20(1):13-8.

Sevoflurane and emergence behavioral changes in pediatrics.

Moos DD.

Sevoflurane has rapidly replaced halothane as the inhaled anesthetic agent of choice for the pediatric population. Benefits of sevoflurane use include a quick induction and emergence from anesthesia, a nonpungent odor, which allows for mask induction, and decreased airway irritation, which results in a decrease in the incidence of bronchospasm and laryngospasm. Despite the positive aspects of sevoflurane, there are several side effects, including seizures during induction and maintenance, elevations in plasma inorganic fluoride and compound A concentrations, and an increased incidence of emergence delirium when compared to halothane. The purpose of this article is to inform perianesthesia nurses of the common complication of emergence behavioral changes associated with sevoflurane.

PMID: 15688330 [PubMed - in process]

Full report available at: http://ehp.niehs.nih.gov/members/2004/7077/7077.html
Environ Health Perspect. 2005 Jan;113(1):111-7.

A quantitative look at fluorosis, fluoride exposure, and intake in children using a health risk assessment approach.

Erdal S, Buchanan SN.

Division of Environmental and Occupational Health Sciences, School of Public Health, University of Illinois at Chicago, Chicago, Illinois 60613, USA. erdal@uic.edu

The prevalence of dental fluorosis in the United States has increased during the last 30 years. In this study, we used a mathematical model commonly employed by the U.S. Environmental Protection Agency to estimate average daily intake of fluoride via all applicable exposure pathways contributing to fluorosis risk for infants and children living in hypothetical fluoridated and nonfluoridated communities. We also estimated hazard quotients for each exposure pathway and hazard indices for exposure conditions representative of central tendency exposure (CTE) and reasonable maximum exposure (RME) conditions. The exposure pathways considered were uptake of fluoride via fluoridated drinking water, beverages, cow's milk, foods, and fluoride supplements for both age groups. Additionally, consumption of infant formula for infants and inadvertent swallowing of toothpaste while brushing and incidental ingestion of soil for children were also considered. The cumulative daily fluoride intake in fluoridated areas was estimated as 0.20 and 0.11 mg/kg-day for RME and CTE scenarios, respectively, for infants. On the other hand, the RME and CTE estimates for children were 0.23 and 0.06 mg/kg-day, respectively. In areas where municipal water is not fluoridated, our RME and CTE estimates for cumulative daily average intake were, respectively, 0.11 and 0.08 mg/kg-day for infants and 0.21 and 0.06 mg/kg-day for children. Our theoretical estimates are in good agreement with measurement-based estimates reported in the literature. Although CTE estimates were within the optimum range for dental caries prevention, the RME estimates were above the upper tolerable intake limit. This suggests that some children may be at risk for fluorosis.

PMID: 15626657 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15663310
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2005;40(1):193-202.

Recovering industrial sludge-derived slag as fine aggregate.

Huang YC, Li KC, Chiang HH.

Department of Land Management and Development, Chang Jung Christian University, Tainan, Taiwan.

This study presents the result of using melting to recover both industrial sludge slag (the main constituent of which is calcium fluoride) and water works sludge slag as fine aggregate in cement. The main characteristics of both slag and cement mortars were measured to evaluate the feasibility of using slag as aggregate. In this study, the slag replacement ratios were 0, 10, 20, 30, 40, and 50% (w/w), and the curing periods were 7, 28, and 90 days. Slag quality was determined according to the standards of fine aggregates in the ASTM specifications, and cement mortars with various slag replacement ratios were evaluated based on their compressive strength, and Toxicity Characteristic Leaching Procedure (TCLP). The crushed slag produced in this study met the ASTM standards for fine aggregate, including gravity, unit weight, absorption, and grading, and the TCLP leached concentrations are far below existing limits, establishing the safety and suitability of slag as fine aggregate. The TCLP leached concentrations of slag and cement mortar were not significantly related to the replacement ratio, and declined with increasing curing period, revealing that the hydration strongly influenced metal leaching. The compressive strength test results of the cement mortars demonstrated that the optimal replacement ratio for maximizing compressive strength was 40%. This study also discussed the effects of replacement ratio and curing periods on cement mortars.

PMID: 15663310 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15642041
Community Dent Oral Epidemiol. 2005 Feb;33(1):1-8.

Total fluoride intake in children aged 22-35 months in four Colombian cities.

Franco AM, Martignon S, Saldarriaga A, Gonzalez MC, Arbelaez MI, Ocampo A, Luna LM, Martinez-Mier EA, Villa AE.

CES University, Medellin, Columbia.

Objective: To obtain information on the level of total fluoride intake from food, beverages and toothpaste by children at the age of 22-25 months of low and high socioeconomic status (SES) in major Colombian cities.
Methods: Daily fluoride intake was assessed by the duplicate plate method and by recovered toothpaste solution during a 3-day period and afterwards analysed by the microdiffusion method.
Results: Mean daily fluoride intake was 0.11 (+/-0.10), 0.14 (+/-0.12), 0.10 (+/-0.07) and 0.07 (+/-0.06) mg/kg body weight (bw)/day in Bogota, Medellin, Manizales and Cartagena, respectively. The total fluoride intake was higher in low-SES subjects in the cities of Medellin and Bogota. In the high-SES children of the four cities, the average intakes ranged from 0.06 to 0.09 mg F/kg bw, whereas, the low-SES children in three cities had intakes between 0.11 and 0.21 mg F/kg bw (Cartagena, 0.07). Toothpaste (containing 1000-1500 ppm F, with 1500 ppm F being more common) accounted for approximately 70% of total fluoride intake, followed by food (24%) and beverages (<6%). More than half the children had their teeth brushed by an adult, on average twice a day, using 0.22-0.65 g of toothpaste.
Conclusion: Children from three Colombian cities have a mean total daily fluoride intake above the 'optimal range'. Health authorities should promote an appropriate use of fluoridated dentifrices discouraging the use of dentifrices containing 1500 ppm F in children younger than 6 years of age and promoting a campaign of education of parents and oral health professionals on adequate toothbrushing practices.

PMID: 15642041 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15695844
Biol Trace Elem Res. 2005 Jan;103(1):1-16.

Health effects of natural dust: role of trace elements and compounds.

Cook AG, Weinstein P, Centeno JA.

School of Population Health, University of Western Australia, Crawley, Western Australia 6009.

This article reviews the health effects of trace elements carried in natural dusts of geologic or geochemical origin. The sources of these dusts are diverse, including volcanoes, dust storms, long-range transport of desert dust, and displacement through natural processes such as landslides and earthquakes. The primary focus is dust exposures affecting communities rather than occupational groups (which have been comprehensively explored in other publications). The principal elements and compounds reviewed are trace metals (including As, Hg, Cd, and Fe), radioactive elements, fluoride, silicates, natural asbestiform compounds, and alkali salts. The pathways by which such agents affect human populations are explored, including carriage through water, air, soil, and the food chain. The mechanisms of biotoxicity and the acute and chronic consequences on health associated with these elements are described. The discussion explores problems inferring risk and disease causation from natural dust exposures using standard epidemiological indicators, particularly for chronic outcomes, and will argue for the importance of the ecological perspective in assessing pathogenesis. The authors stress the global scale of the problem, which remains underevaluated and underreported in terms of health implications.

PMID: 15695844 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15591730
Caries Res. 2005 Jan-Feb;39(1):20-6.

The effect of five years' implementation of caries-preventive methods in Swedish high-risk adolescents.

Kallestal C.

National Institute of Public Health, SE-103 52 Stockholm, Sweden. carina.kallestal@fhi.se

AIM: To study the effectiveness of four different preventive programmes within a group of adolescents at high risk of caries.
SUBJECTS AND METHODS: In 1995, a cohort of 12-year-olds was examined for caries and completed a questionnaire. Subjects identified as being at high risk were examined every year until 2000 when they were 17 years old. This high-risk group was subdivided into four groups, each individual randomly assigned to one of four preventive programmes:
(A) information on tooth-brushing techniques;
(B) prescription of fluoride lozenges;
(C) semi-annual applications of fluoride varnish;
(D) quarterly appointments where participants were given individualised information on oral hygiene and diet as well as an application of fluoride varnish.
The outcomes examined were the caries increment in dentine, enamel and fillings. Poisson regression was used to assess the influence of background, preventive factors and habits.
RESULTS: The number of 12-year-olds in the high-risk group was 1,134 in 1995, of which 925 were still participants in 2000. The differences between the programmes in mean 5-year increment were not significant. Less risk of caries increment was shown for those who had at least one sealant and for those who belonged to the fluoride varnish group (C). A higher risk was observed for adolescents from working-class homes, and for those who reported often eating sweets and not brushing their teeth twice a day at all examinations during the whole study period.
CONCLUSIONS: The preventive programmes tested were equal in showing low efficiency in adolescents with high caries risk. Copyright 2005 S. Karger AG, Basel.

PMID: 15591730 [PubMed - in process]

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15607263
Int J Pharm. 2005 Jan 6;288(1):109-122. Epub 2004 Nov 18.

Development and evaluation of extended release bioadhesive sodium fluoride tablets.

Owens TS, Dansereau RJ, Sakr A.

Industrial Pharmacy Graduate Program, College of Pharmacy, University of Cincinnati, 3223 Eden Ave., Cincinnati 45219, OH, USA.

Localized fluoride delivery to the oral cavity is important in caries prevention. However, no current marketed dosage forms deliver fluoride for an extended period. This work describes the effect of poly (methyl vinyl ether-co-maleic anhydride) mixed calcium/sodium salt (Gantrez MS), sodium carboxymethylcellulose (NaCMC), polyethylene glycol 8000 (PEG8000) and Carbopol 934 (C934) on the in vitro dissolution and ex vivo bioadhesion of sodium fluoride matrix tablets. Dissolution was studied using USP Apparatus 2 and a low volume (3.1ml), low flow (0.5ml/min) dissolution apparatus. In both apparatus, the percent drug dissolved at 2, 4 and 8h was found to be statistically dependent on the fractions of Gantrez MS and NaCMC. The interaction term was significant at 2 and 4h (probability>{t} of less than 0.05). Ex vivo bioadhesion was studied using excised bovine gingiva and a TA.XT2i Texture Analyzer. Peak bioadhesive force and work of bioadhesion were found to be statistically dependent on the fractions of Gantrez MS and NaCMC with no interaction (probability>{t} of less than 0.01). Results indicate that bioadhesive matrix fluoride tablets of these mixtures can be designed to exhibit both bioadhesive and extended release properties.

PMID: 15607263 [PubMed - as supplied by publisher]

Back to the top

Return to FAN's Pesticide Homepage

Fluoride Action Network | Pesticide Project | 315-379-9200 | pesticides@fluoridealert.org