Pub
Med Abstract
Rev Saude Publica. 2007
Aug;41(4):549-56.Click here to read Links
[Fluoride concentrations in typical
Brazilian foods and in infant foods.]
[Article in Portuguese]
Casarin RC, Fernandes DR, Lima-Arsati
YB, Cury JA.
Departamento de Ciências Fisiológicas,
Faculdade de Odontologia de Piracicaba, Universidade Estadual
de Campinas, Piracicaba, SP, Brasil.
OBJECTIVE: To determine fluoride concentrations
in the typical Brazilian meal (rice with beans) and in
processed infant foods, and to estimate their contribution
towards dental fluorosis.
METHODS: The foods were purchased at supermarkets in the
cities of Piracicaba and Campinas, Southeastern Brazil.
The processed infant foods were bought in 2001 and the
rice and beans in 2003, and they were analyzed immediately.
Three brands of rice, three brands of beans and 36 samples
of infant foods were analyzed, divided into five groups:
ready-to-eat, porridges, formulated foods, powdered milk
and others. For the rice and beans, fluoride concentrations
were determined in the raw grains and after they were
cooked with fluoridated (0.7 ppm) or distilled water.
All the fluoride analyses were performed using a specific
electrode. A dose of 0.07 mg/kg/day was considered to
be the upper limit of fluoride exposure in terms of fluorosis
risks.
RESULTS: The fluoride concentrations
found in the grains of rice and beans were low. However,
they increased 100 to 200-fold after cooking in fluoridated
water. Even so, they were lower than what is found
in some processed foods. A meal of rice and beans prepared
with fluoridated water would be responsible for 29% of
the threshold dose for fluoride intake in terms of acceptable
fluorosis; the contribution from some processed foods
reaches 45%.
CONCLUSIONS: The typical Brazilian food, even when prepared
with fluoridated water, is safer in terms of the risk
of dental fluorosis than are some processed infant foods.
PMID: 17589752 [PubMed - in process]
|
Full report at Science Direct
Aquaculture Volume 269, Issues 1-4, 14 September 2007,
Pages 525-531
Fluorine accumulation in Atlantic salmon
(Salmo salar), Atlantic cod (Gadus morhua), rainbow trout (Onchorhyncus
mykiss) and Atlantic halibut (Hippoglossus hippoglossus) fed diets
with krill or amphipod meals and fish meal based diets with sodium
fluoride (NaF) inclusion
Moren M (a), Malde MK (a), Olsen RE (b), Hemre GI (a), Dahl
L (a), Karlsen Ø (c), Julshamn K (a)
(a) National Institute of Nutrition and Seafood Research (NIFES),
P.O. Box 2029 Nordnes, N-5817 Bergen, Norway
(b) Institute of Marine Research, Matre Research Station, N-5984
Matredal, Norway
(c) Institute of Marine Research, Austevoll Research Station,
N-5392 Storebø, Norway
Excerpt from Abstract:
... The four fish species, when kept in a marine
environment, were not affected by relatively high dietary fluorine
level.
Excerpt from Introduction.
Traditionally, diets used for carnivorous fish have been based
on meal and oil obtained from pelagic fish species. World catches
of these species are already at a maximum (FAO, 2004) and alternative
nutrient sources are necessary in order to support further growth
in intensive aquaculture. As alternative plant ingredients have
major limitations, such as high contents of anti-nutrients (Krogdahl
et al., 2005) in the protein fraction, and unbalanced fatty acid
profiles in plant oils (Oxley et al., 2005), the possibility of
using unexploited biomasses in the oceans to replace fish meal
and oil is intriguing (CCAMLR, 2005). Various krill species, which
are found in large quantities in the oceans (CCAMLR, 2005), are
a natural part of the feed of wild fish and should be well suited
as feed sources. The suitability of krill as feed was subject
of several studies in the late 70s and 80s.
The general conclusion was that krill could be used in fish diets,
but the results were not followed up partly because of the high
fluorine content found in the krill species investigated (1000–6000
mg kg- 1). The highest concentration of fluorine was found in
Antarctic coastal krill (Euphausia crystallorophias).
When fluorine is dissolved in water, levels
down to 0.5 mg L- 1 may be toxic to fish, in particular those
living in “soft waters”. The
toxicity of fluorine decreases with increasing hardness (CaCO3
mg L- 1) and increasing chlorine concentration, and decreasing
temperature (reviewed by Camargo, 2003). Feeding trials
carried out with fish in fresh or brackish water using krill as
feedstuff increases bone fluorine content ([Grave, 1981], [Thiews
et al., 1982] and [Yoshitomi et al., 2006]). However, a recent
study where adult Atlantic salmon were fed krill diets in seawater
environments found no increase in bone fluorine in spite of krill
replacing up to 30% of fish meal (Julshamn et al., 2004). EU
has set a maximum level for fluorine in feeds and feed ingredients
at 150 mg kg- 1 (88% dry wt. basis). The
only exception is krill where the upper limit is set to 3000 mg
F- kg- 1 (88% dry wt basis). However
the final diet concentration must still be below 150 mg kg- 1
(88% dry wt. basis) (EU
directive, 2005/87/EC).
Excerpt
from Discussion...
To our knowledge fluorine contents of amphipods have only once
been reported in international journals. Sands et al. (1998) collected
several crustacean species in the Antarctic/Southern oceans and
identified the amphipod Cyphocaris micronyx. The average fluorine
concentration found in whole body of this species was 120 ±
50 mg kg- 1 dry wt. (Sands et al., 1998). Thus, it seems that
high fluorine levels are not a common trait for amphipods. It
is possible that fluorine is a hardener in the exoskeleton similar
to what has been proposed for krill (Zhang et al., 1993). If so,
the fact that T. libellula has a relatively thick exoskeleton
which constitutes a higher percentage of the total body mass compared
to krill would result in a relatively higher level of fluorine...
by feeding krill to fish held in brackish
or fresh water several studies has shown significant increase
in fluorine in bones compared to those fed fish meal based diets
([Grave, 1981], [Thiews et al., 1982] and [Yoshitomi et al., 2006]).
In contrast, when Julshamn et al. (2004) fed salmon diets with
30% krill meal inclusion they did not find any increase in fluorine
contents in bone tissue. The latter result resembles the results
from the present paper, where none of the experimental diets caused
increases in fluorine either in scales or bones. These discrepancies
may be due to the possible effect of water salinity. The
fluorine toxicity decreases with increasing water levels of chloride
and calcium, hence with increasing salinity. There might
be a similar effect of salinity on uptake and subsequent the toxicity
of fluorine from fish diets. This was also suggested by Yoshitomi
et al. (2006) who found increased fluorine levels in bones of
rainbow trout when fed a krill meal based diet in freshwater.
Using a fish meal based diet with NaF inclusion did not increase
the fluorine concentrations in bones or other analysed organs.
E.g. neither fluorine from krill nor from NaF was stored in the
organs. This indicates that the inorganic fluorine added as NaF
was not metabolised differently from the fluorine coming from
krill. As there was no increase in fluorine contents in the bones
of either salmon, cod, halibut or rainbow trout fed increasing
levels of krill meal, the effect of salinity
might be a general effect on fish in the marine environment. This
has yet to be proven.
PubMed Abstract
Chemosphere. 2007 Dec 4 [Epub ahead of print]
Study of the use of coal fly ash as an additive to minimise fluoride leaching from FGD gypsum for its disposal.
Alvarez-Ayuso E, Querol X.
Department of Environmental Geology, Institute of Earth Sciences “Jaume Almera” (CSIC), C/Lluís Solé i Sabarís, s/n, 08028 Barcelona, Spain.
The use of coal fly ash as a fluoride retention additive has been studied as a way of treating flue gas desulphurisation (FGD) gypsum for its disposal in landfills. With this end leaching studies following the standard EN-12457-4 [Characterization of waste- Leaching-Compliance test for leaching of granular waste materials and sludges - Part 4: One stage batch test at a liquid to solid ratio of 10l/kg for materials with particle size below 10mm (without or with size reduction)] have been performed on FGD gypsum samples treated with different proportions of fly ash (0.1-100%). It was found that the fluoride leachable content in FGD gypsum was reduced in the range 1-55%, depending on the fly ash proportion added to FGD gypsum. High levels of fluoride leaching reduction (close to 40%) were achieved even at relatively low fly ash additions (5%). So, low fly ash incorporations assure the characterization of this by-product as a waste acceptable at landfills for non-hazardous wastes according to the Council Decision 2003/33/EC [Council Decision 2003/33/EC of 19 December 2002 establishing criteria and procedures for the acceptance of waste at landfills pursuant to Article 16 of and Annex II to Directive 1999/31/EC] on waste disposal. Furthermore, the effectiveness of the proposed FGD gypsum stabilization method was also studied in column leaching systems, proving its good performance in simulated conditions of disposal. In such conditions a fluoride leaching reduction value slightly higher than 25% was displayed for a fly ash added amount of 5%.
PMID: 18063008 [PubMed - as supplied by publisher]
PubMed Abstract
Environ Monit Assess. 2007 Dec 7
Survey on fluoride, bromide and chloride contents in public drinking water supplies in Sicily (Italy).
D'Alessandro W, Bellomo S, Parello F, Brusca L, Longo M.
Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, via La Malfa 153, 90146, Palermo, Italy, w.dalessandro@pa.ingv.it.
Six hundred and sixty-seven water samples were collected from public drinking water supplies in Sicily and analysed for electric conductivity and for their Cl(-), Br(-) and F(-) contents. The samples were, as far as possible, collected evenly over the entire territory with an average sampling density of about one sample for every 7,600 inhabitants. The contents of Cl(-) and Br(-), ranging between 5.53 and 1,302 mg/l and between <0.025 and 4.76 mg/l respectively, correlated well with the electric conductivity, a parameter used as a proxy for water salinity. The highest values were found both along the NW and SE coasts, which we attributed to seawater contamination, and in the central part of Sicily, which we attributed to evaporitic rock dissolution. The fluoride concentrations ranged from 0.023 to 3.28 mg/l, while the highest values (only three exceeding the maximum admissible concentration of 1.5 mg/l) generally correlated either with the presence in the area of crystalline (volcanic or metamorphic) or evaporitic rocks or with contamination from hydrothermal activity. Apart from these limited cases of exceeding F(-) levels, the waters of public drinking water supplies in Sicily can be considered safe for human consumption for the analysed parameters. Some limited concern could arise from the intake of bromide-rich waters (about 3% exceeding 1 mg/l) because of the potential formation of dangerous disinfection by-products.
PMID: 18064536 [PubMed - as supplied by publisher]
PubMed
abstract
Isotopes Environ Health Stud. 2007
Jun;43(2):165-75.
Anomalous fluoride concentration in groundwater
- is it natural or pollution? A stable isotope approach.
Marimon MP, Knöller K, Roisenberg A.
Universidade do Estado de Santa Catarina, Lagoa da Conceição,
Florianópolis/SC, Brazil. f2mpcm@udesc.br
Fluoride anomalies (up to 11 mg/l)
have been detected in groundwater of the
central region of Rio Grande do Sul State, Southern Brazil, in
an area where fluorosis is endemic. Two hypotheses are
investigated concerning the fluoride origin:
lithochemical affiliation from regional rock or contamination
by fertilisers application. These hypotheses are discussed
based on the stable isotope data of water, nitrate, and sulphate,
which indicates that the local precipitation is the main groundwater
recharge source. The isotopic composition of groundwater sulphate
is similar to that of fertiliser sulphate. However, a conclusive
assignment of groundwater sulphate to fertiliser origin is not
indicated because further possible sulphate sources fall into
the same isotopic range. In contrast, the isotopic composition
of dissolved nitrate suggests that there is no direct relationship
to the use of NPK fertilisers. Hence, an
origin of the high fluoride content in groundwater related to
long-term rock-water interactions seems likely.
PMID: 17558753 [PubMed - in process]
PubMed
abstract
Acta Odontol Scand. 2007 Jun;65(3):149-55.
Photographic assessment of fluorosis in
children from naturally fluoridated Kungsbacka and non-fluoridated
Halmstad, Sweden.
Macpherson LM, Conway DI, Gilmour WH, Petersson LG, Stephen KW.
Dental Public Health Unit, University of Glasgow Dental School,
Glasgow, UK. l.macpherson@dental.gla.ac.uk
OBJECTIVES: To assess levels of fluorosis and fluorosis of esthetic
concern in children from a naturally fluoridated and a non-fluoridated
area of Sweden, and to determine the relative contributions of
fluoridated water, parental educational level, and infant oral
health-related behaviors.
METHODS: A parental questionnaire collected information concerning
child F-supplement and F-dentifrice usage histories, and socio-economic
status. Photographic examination of 1336 subjects (F=791; N-F=545)
was undertaken. Fluorosis was assessed (blind to F-exposure) in
a random sample (n=250) of 35 mm slides by four dental and two
lay "jurors" (with 10% random repeat-viewing for inter-observer
and intra-observer agreement). Four outcomes were assessed on
each slide: fluorosis at any level, fluorosis of esthetic concern,
acceptability of appearance, and treatment needs. Ordinal logistic
regression models were used to determine significant determinants.
RESULTS: For presence of fluorosis of esthetic concern, majority
jury agreements (>3 of 6) were seen in only 2.3% (N-F) and
13.4% (F) pupils (p<0.001), albeit jurors unanimously scored
only 13 F and 2 N-F exposed children as having esthetically unacceptable
fluorosed teeth (p<0.001). The over-riding significant factor
in terms of fluorosis of esthetic concern was exposure to water
fluoridation in infancy in both unadjusted and adjusted models.
CONCLUSIONS: The important factor in relation
to fluorosis of esthetic concern was explained by exposure to
fluoridated water in infancy, and was not explained by
age, sex, level of parental education or early childhood oral
health behaviors. However, prevalence of this condition was relatively
low. These findings should inform policies on appropriate total
fluoride exposure levels during infancy.
PMID: 17514516 [PubMed - in process]
PubMed Abstract
Environ Monit Assess. 2007 Oct 27 [Epub ahead of print]
Fluoride contamination in drinking water in rural habitations of Northern Rajasthan, India.
Suthar S, Garg VK, Jangir S, Kaur S, Goswami N, Singh S.
Environmental Biology Laboratory, Post Graduate Department of Zoology, S.G.N. Khalsa (PG) College, Sri Ganganagar, 335 00, India, sutharss_soilbiology@yahoo.co.in.
This study was carried out to assess the fluoride concentration in groundwater in some villages of northern Rajasthan, India, where groundwater is the main source of drinking water. Water samples collected form deep aquifer based hand-pumps were analysed for fluoride content. Fluoride in presently studied sites was recorded in the ranges of 4.78 and 1.01 mg/l. The average fluoride concentration for this region was recorded 2.82 mg/l. As per the desirable and maximum permissible limit for fluoride in drinking water, determined by WHO or by Bureau of Indian Standards, the groundwater of about 95 of the studied sites is unfit for drinking purposes. Due to the higher fluoride level in drinking water several cases of dental and skeletal fluorosis have appeared at alarming rate in this region. The middle and eastern parts of the Hanumangarh, a northern most district of the state, can be classified as higher risk area for fluorosis; due to relatively high concentrations of fluoride (3-4 mg/l) in groundwater of this region. After evaluating the data of this study it is concluded that there is an instant need to take ameliorative steps in this region to prevent the population from fluorosis.
PMID: 17965944 [PubMed - as supplied by publisher]
PubMed
N Y State Dent J. 2007 Aug-Sep;73(5):12;
Fluoride vs. decontamination.
Zadik Y.
No abstract
PMID: 17969475 [PubMed - in process]
PubMed
abstract
Environ Technol. 2007 Jun;28(6):595-607.
Screening of commercial sorbents for removal
of fluoride in synthetic and groundwater.
Hernández-Montoya V, Elizalde-González MP, Trejo-Vázquez
R.
Departamento de Ing. Química, Instituto Tecnológico
de Aguascalientes, Apdo. Postal 616-1, Aguascalientes, Ags. 20360,
Mexico.
Numerous methods have been described employing various materials
for fluoride removal due to the risk of high fluoride dosing for
human health. There is a broad collection of commercial products
for adsorption applications. The materials
most recommended are activated alumina and bone char. Nineteen
commercial sorbents were screened for fluoride removal in static
experiments, with synthetic water and groundwater from the city
of Aguascalientes (México), where some wells contain up
to 15 mg l(-1) of fluoride. Removal efficiency of aluminas and
activated carbons with a uniform particle diameter of 0.63 mm
was compared. Four materials leading to a final concentration
of 1 mg F- l(-1) were selected, pretreated, and characterized
(X-ray diffractometry, infrared spectroscopy, titration, methylene
blue and nitrogen adsorption) for further investigation. Adsorption
rate constant was determined and obeyed a pseudo-first order equation.
Fluoride removal was clearly improved after the conditioning procedure
and was higher for aluminas than for bone carbons. The pretreated
sample A5 adsorbed 5 mg g(-1) at 25 degrees C and pH 6 from a
20 mg F- l(-1) synthetic water solution after 7 hours by using
a sorbent dose of 4 mg ml(-1). The specific saturation capacity
with fluoride was aluminas - carbons for determined samples (10
mg g(-1), but the superficial capability was higher for the pretreated
bone carbon sample CH5 (50 microg m(-2)) because of its higher
acidity. At wells 4 and 5 (7.1 mg F- l(-1)) the reached efficiency
was 91% for aluminas and 70% with bone carbon.
PMID: 17624100 [PubMed - in process]
PubMed
abstract
Community Dent Oral Epidemiol. 2007
Aug;35(4):282-91.
Decline in the prevalence of dental fluorosis
among South Australian children.
Do LG, Spencer AJ.
Australian Research Centre for Population Oral Health, The University
of Adelaide, Australia.
Background: The use of fluoride involves a balance between protection
against dental caries and risk of dental fluorosis. Fluorosis
in Australian children was highly prevalent in the early 1990s.
Policy measures were introduced to control fluoride exposure so
as to reduce the prevalence of fluorosis. Objective: To evaluate
the effectiveness of policy measures in reducing the prevalence
of fluorosis among Australian children.
Methods: A random sample of South Australian children born in
1989-1994 was selected in 2002/2003, stratified by fluoridation
status and urban/rural residence. Children were targeted to form
three successive birth cohorts: those children born in 1989/1990,
1991/1992 and 1993/1994, respectively. Fluoride exposures were
assessed by questionnaire. One dentist examined 677 children for
fluorosis using the Thylstrup and Fejerskov (TF) Index. Data were
reweighted to reflect the state's child population. Case definitions
of fluorosis were: having a TF score of 1+ (TF1+) or a TF score
of 2+ (TF2+) on one or both maxillary central incisors.
Results: A higher proportion of children in the later birth cohorts
used low-concentration fluoridated toothpaste, and a smaller amount
of toothpaste was used when they commenced toothbrushing. The
fluorosis experience in this population was mostly very mild to
mild. There was a significant decline in the prevalence of fluorosis
across the three successive birth cohorts. The prevalence of fluorosis
by TF1+ case definition declined from 34.7% to 22.1% and by TF2+
case definition from 1
7.9% to 8.3%. Risk factors for fluorosis were use of standard-concentration
fluoridated toothpaste, an eating and/or licking toothpaste habit
and exposure to fluoridated water. Conclusion: The experience
of fluorosis among the South Australian child population was mostly
very mild to mild. There was a marked decline
in the prevalence of fluorosis across the three successive birth
cohorts. The decline was mainly linked with the reduction in exposure
to fluoride from fluoridated toothpaste.
PMID: 17615015 [PubMed - in process]
PubMed
abstract
Quintessence Int. 2007 Jun;38(6):459-65.
Prevalence of caries and fluorosis in
adolescents in Iran.
Meyer-Lueckel H, Bitter K, Shirkhani B, Hopfenmuller W, Kielbassa
AM.
Objective: To determine the caries and fluorosis prevalence of
adolescents in 3 communities in Iran with varying urbanization
and concentrations of fluoride in the piped water.
Method and Materials: Data were obtained from 593 examinations
of 12- and 15-year-olds in Tehran (water fluoride concentration:
0.3 mg F/L), the city of Semnan (1.3 mg
F/L), and the village Dibaj (0.2 mg F/L) in Iran.
Results: In both age groups, comparable counts of decayed, missing,
and filled surfaces (DMFS) were observed, whereas the values related
to teeth (DMFT [SD]) were significantly
higher in 12-year-olds from Semnan (1.5 [1.8]) than those
for children from Dibaj (0.7 [1.0]) (P <.05; Mann-Whitney test)
but comparable to those for children in Tehran (1.2 [0.7]). A
lower prevalence of dental restorations was reported for both
Semnan and Dibaj (Unmet Restorative Index [UNT]: 67% to 82%) compared
to Tehran (15% to 39%). In Semnan, the risk
of having medium to severe fluorosis was 10- and 34-fold compared
to Tehran and Dibaj, respectively.
Conclusions: Caries prevalence was relatively low compared to
that in other countries in the Middle East. In the examined population,
which was not adjusted to socioeconomic status, naturally fluoridated
water seemed to have no obvious effects on DMFT, but resulted
in an esthetically relevant higher prevalence of dental fluorosis.
(Quintessence Int 2007;38:459-465).
PMID: 17625628 [PubMed - in process]
PubMed
abstract
Sci Total Environ. 2007 Jul 25;
[Epub ahead of print]
Fluorine geochemistry in bedrock groundwater
of South Korea.
Chae GT, Yun ST, Mayer B, Kim KH, Kim SY, Kwon JS, Kim K, Koh
YK.
Department of Earth and Environmental Sciences and the Environmental
Geosphere Research Lab (EGRL), Korea University, Seoul 136-701,
Republic of Korea; Korea Institute of Geoscience and Mineral Resources,
Daejeon 305-350, Republic of Korea.
High fluoride concentrations (median=4.4 mg/L) in deep bedrock
groundwater of South Korea prevent the usage of it as a drinking
water source. The hydrogeochemistry of deep thermal groundwaters
(N=377) in diverse bedrocks has been studied in order to evaluate
the geologic and geochemical controls on fluoride concentrations
in groundwater. The groundwater samples were clustered geologically,
and the average and median concentrations of fluoride were compared
by the Mann-Whitney U test. The order of median fluoride concentration
with respect to geology is as follows: metamorphic rocks>/=granitoids>/=complex
rock>>volcanic rocks>/=sedimentary rocks. This result
indicates that the geological source of fluoride in groundwater
is related to the mineral composition of metamorphic rocks and
granitoids. With respect to groundwater chemistry, the fluoride
concentration was highest in Na-HCO(3) type groundwater and lowest
in Ca-HCO(3) type groundwater. Ionic relationships also imply
that the geochemical behavior of fluoride in groundwater is related
to the geochemical process releasing Na and removing Ca ions.
The thermodynamic relationship between the activities of Ca and
F indicates that fluoride concentration is controlled by the equilibrium
of fluorite (CaF(2)). In other words, the
upper limits of fluoride concentration are determined by the Ca
ion; i.e., Ca concentrations play a crucial role in fluoride behavior
in deep thermal groundwater. The result of this study suggests
that the high fluoride in groundwater originates from geological
sources and fluoride can be removed by fluorite precipitation
when high Ca concentration is maintained. This provides a basis
for a proper management plan to develop the deep thermal groundwater
and for treatment of high fluoride groundwater frequently found
in South Korea.
PMID: 17655916 [PubMed - as supplied by publisher]
PubMed
abstract
J Dent Res. 2007 Aug;86(8):723-8.
Risk-Benefit Balance in the Use of Fluoride among Young
Children.
Do LG, Spencer AJ.
Australian Research Centre for Population Oral Health, School
of Dentistry, The University of Adelaide, Australia 5005.
This study aimed to evaluate the risk-benefit balance of several
fluoride exposures. Fluoride exposure history of randomly selected
children was collected for calculation of exposure to fluoridated
water, toothpaste, and other fluoride sources. We evaluated the
risk-benefit balance of fluoride exposure by comparing dental
fluorosis on maxillary central incisors, recorded at the time
of the study with the use of the Thylstrup and Fejerskov Index,
and deciduous caries experience, recorded at age six years, of
the same group of South Australian children who were from 8 to
13 years old in 2002-03. Population Attributable Risk for fluorosis
and Population Prevented Fraction for caries were estimated. Fluorosis
prevalence was found to be 11.3%; caries prevalence, 32.3%; mean
dmfs, 1.57 (SD 3.3). Exposure to fluoridated water was positively
associated with fluorosis, but was negatively associated with
caries. Using 1000-ppm-F toothpaste (compared with 400- to 550-ppm-F
toothpaste) and eating/licking toothpaste were associated with
higher risk of fluorosis without additional benefit in caries
protection. Evaluation of the risk-benefit balance of fluoride
exposure provides evidence to assist in the formulation of appropriate
guidelines for fluoride use.
PMID: 17652199 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17453423&query_hl=1&itool=pubmed_docsum
Acta Odontol Scand. 2007 Apr;65(2):65-71.
Dental fluorosis in children in areas
with fluoride-polluted air, high-fluoride water, and low-fluoride
water as well as low-fluoride air: A study of deciduous and permanent
teeth in the Shaanxi province, China.
Ruan JP, Bardsen A, Astrom AN, Huang RZ, Wang ZL, Bjorvatn K.
Department of Oral Science, Faculty of Dentistry, University
of Bergen. Norway.
Objective. The aim of the study was to assess dental fluorosis
(DF) in the deciduous and permanent teeth of children in areas
with high-F coal (area A) and high-F water
(area C) compared to children from area
B, with low-F water and coal.
Material and Methods. 596 children were examined. DF was assessed
by TF-score. F-content of indoor air, drinking water, coal, tea,
rice, and maize was analyzed. Results. F-content of air and coal
ranged from 3.2 microg/m(3) and 25.8 mg/kg (area B), 3.8 microg/m(3)
and 36.3 mg/kg (area C) to 56.8 microg/m(3) and 713.1 mg/kg (area
A). Likewise, mean F-content of water ranged from approximately
0.50 mg/l (areas A and B) to 3.64 mg/l (area C). F-content of
tea leaves was similar in all three areas. Maize and rice contained
<5 mg F/kg. Prevalence of primary teeth with DF was 49.1%,
2.0%, and 66.8% in areas A, B, and C, respectively. Similarly,
DF was found in 96.7% (area A), 19.6% (area B), and 94.4% (area
C) of the permanent teeth. Severe fluorosis (TF >/= 5) was
found in area A (47.0%) and area C (36.1%) (p<0.01). Early
erupting teeth had slightly higher mean TF-scores in area A than
in area C. Conclusions. DF was prevalent in both dentitions in
areas A and C. Similarity in percentages of DF may indicate that
indoor air with approximately 60 microg F/m(3) and drinking water
with 3.6 mg F/L are similarly toxic to developing permanent teeth.
The percentage of deciduous teeth with DF
was significantly lower in area A compared to area C. Where low-F
coal and low-F water were used (area B), approximately 20% of
permanent teeth had DF, indicating a relatively low tolerance
to fluoride in Chinese children brought up under the present living
conditions.
PMID: 17453423 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17451504&query_hl=1&itool=pubmed_docsum
Eur J Oral Sci. 2007 Apr;115(2):137-42.
Dental fluorosis and dental caries among
12-yr-old children from high- and low-fluoride areas in Lithuania.
Narbutaite J, Vehkalahti MM, Milciuviene S.
Clinic for Preventive and Paediatric Dentistry, Kaunas University
of Medicine, Kaunas, Lithuania.
We investigated the prevalence and severity of dental fluorosis,
and the occurrence of dental caries, among 12-yr-old children
from high- and low-fluoride areas in a country with high caries
figures and a developing oral healthcare system. The sample included
a total of 600 lifetime residents from high-fluoride (HF; 1.7-2.2
ppm) and low-fluoride (LF; 0.2 ppm) areas in Lithuania. The diagnoses
of dental fluorosis followed the Thylstrup-Fejerskov Index (TF),
and a diagnosis of dental caries followed the World Health Organization
criteria. In the HF area, 66% of the 12-yr-old children had dental
fluorosis (TF score > 0) compared with 4% in the LF area. The
maximum TF severity scores were 7 and 3, respectively. The
mean number of teeth with fluorosis was 4.5 [95% confidence interval
(CI) = 4.0,5.0] for the HF group and 0.2 (95% CI = 0.1,0.2) for
the LF group. In the HF group, 72% had a decayed, missing
or filled teeth (DMFT) score of > 0, compared with 87% in the
LF group. The mean DMFT was 2.0 (95% CI = 1.8,2.3) in the HF group
and 3.5 (95% CI = 3.2,3.8) in the LF group. Current untreated
caries (DT) occured (DT >0) in half of both the HF and LF groups.
Regardless of the concentration of fluoride
in the drinking water, the prevalence of past (DMFT > 0) and
present (DT > 0) caries was high, calling for more emphasis
on the prevention of tooth decay in countries, such as Lithuania,
with high caries figures and a developing oral healthcare system.
PMID: 17451504 [PubMed - in process]
Full paper at Science Direct
Journal of Fluorine Chemistry, Volume 128, Issue 4, April 2007,
Pages 285-295
Advances in Inorganic Fluorine Chemistry
Review
Role of elemental fluorine in nuclear field
H. Groult (a), F. Lantelme (a), M. Salanne (a), C. Simon (a),
C. Belhomme (b), B. Morel (b) and F. Nicolas (c)
a) Université P. & M. Curie-Paris 6, CNRS-UPMC-ESPCI
UMR 7612, Laboratoire LI2C, 4 Place Jussieu, Paris F-75005, France
b) Areva NC, Laboratoire R&D, BP 29, 26700 Pierrelatte Cedex,
France
c) Cogema-Areva, Laboratoire R&D, BP 16, 26700 Pierrelatte
Cedex, France
The preparation of fluorine gas by Henri Moissan by electrolysis
of molten fluorides can be considered as one of the most important
discoveries during the last centuries. Indeed, in addition to
its use in many industrial fields (microelectronic, surface cleaning,
pharmacology, medicine, …), fluorine
gas is strongly involved in nuclear field for the preparation
of UF6. The latter allows the natural uranium enrichment
via the gaseous diffusion process. Due
to the increase of the energy demand in industrialised and emergent
countries, the production of UF6 and consequently of F2 should
increase drastically during the next decades.
The aim of this paper is to summarise the evolution of the process
to produce fluorine from its discovery to the present process.
Few aspects on the researches done for a better understanding
of the fluorine evolution reaction are presented. The use of fluorine
in the nuclear field is also discussed.
Excerpt:
One
of the main uses of fluorine is related to the manufacture
of uranium hexafluoride UF6 which allows the isotopic
enrichment of natural uranium. About 60% of the world
production of F2 is devoted to the synthesis of this
gaseous fluoride compound. For this reason, elemental
fluorine can be considered as a key element for the
preparation of electricity via nuclear plants.
|
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17244138&query_hl=1&itool=pubmed_DocSum
Community Dent Oral Epidemiol. 2007
Feb;35(1):53-63.
Fluoride ingestion from toothpaste and
diet in 1- to 3-year-old Brazilian children.
de Almeida BS, da Silva Cardoso VE, Buzalaf MA.
Bauru Dental School, University of Sao Paulo, Bauru, Brazil.
OBJECTIVE: This study estimated the total daily fluoride intake
of 1- to 3-year-old children from diet and dentifrice. The constituents
of the diet were divided into solids, water, milk, and other beverages,
which were analyzed separately. The correlation between fingernail
fluoride concentrations and the total daily fluoride intake by
children was also investigated.
METHODS: Thirty-three children, living in a fluoridated area,
participated in the study. Fluoride intake from diet was monitored
by the 'duplicate plate' method, investigating the different constituents
of the diet. Fluoride ingested from dentifrice was determined
by subtracting the amount of fluoride recovered after brushing
from the amount originally placed onto the child's toothbrush.
Fingernails were clipped and collected on three occasions. Fluoride
was analyzed with the ion-specific electrode, after hexamethyldisiloxane-facilitated
diffusion. Data were tested by anova and Tukey's post hoc tests,
Student's t-tests and linear regression (P < 0.05).
RESULTS: Mean (+/-SD) fluoride intake from diet and dentifrice
was 0.025 +/- 0.013 and 0.106 +/- 0.085 mg/kg body weight/day,
respectively, totaling 0.130 mg/kg body weight/day. A strong positive
correlation (r = 0.971, P < 0.0001) was seen between the amount
of dentifrice loaded onto the brush (0.49 +/- 0.30 g) and the
amount of fluoride ingested during each tooth brushing (0.59 +/-
0.45 mg). Among the constituents of the diet, water and milk had
a significantly higher contribution to the fluoride intake (0.18
+/- 0.11 mg/day, P < 0.0001), when compared with solids (0.07
+/- 0.05 mg/day) and other beverages (0.07 +/- 0.04 mg/day). Mean
(+/-SD) fingernail fluoride concentration on the three dates of
collection was 3.11 +/- 1.14, 2.22 +/- 1.47 and 3.53 +/- 1.40
mug F/g. There was no significant correlation between fingernail
fluoride concentration and the total fluoride intake.
CONCLUSIONS: Most of the children are exposed
to a daily fluoride intake above the suggested threshold for dental
fluorosis. The dentifrice alone is responsible for an average
of 81.5% of the daily fluoride intake, while among the constituents
of the diet, water and milk are the most important contributors.
In addition, small variations in daily fluoride intake cannot
be detected in fingernails.
PMID: 17244138 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17410113&query_hl=1&itool=pubmed_DocSum
J Expo Sci Environ Epidemiol. 2007
Apr 4; [Epub ahead of print]
Potential exposure and risk of fluoride
intakes from tea drinks produced in Taiwan.
Lung SC, Cheng HW, Fu CB.
[1] aResearch Center for Environmental Changes, Academia Sinica,
Nankang, Taipei, Taiwan [2] bDepartment of Public Health, College
of Health Care and Management, Chung Shan Medical University,
Taichung, Taiwan [3] cDepartment of Atmospheric Sciences, National
Taiwan University, Taipei, Taiwan.
Tea is the second most commonly
consumed drink in the world. Excess fluoride intakes
from tea drinks may cause health effects. This work assesses infusible
fluoride levels in popular tea sold in Taiwan and evaluates potential
exposure factors. Lungjing, pouchong, tienguanyin, oolong, pureh,
and black tea specimens were purchased from different counties
in Taiwan. Fluoride levels were evaluated in one complete cycle
of tea making as well as at different calcium carbonate contents
in water, with glass or porcelain teapots, and with/without adding
sugar. Oolong tea leaves in each manufacturing step were also
analyzed for infusible fluoride. Potential fluoride intakes and
risks are estimated based on a national survey. Among six kinds
of tea, black tea had the highest fluoride concentrations (8.64+/-2.96
mg/l), whereas pureh (1.97+/-2.70 mg/l) had the lowest levels.
Higher percentages of infusible fluoride can be rinsed away from
tea leaves curved lengthways compared to those curved end-to-end
in the first 2.5 min. The use of glass or porcelain teapots and
calcium carbonate content (up to 400 mg/l) in water would not
affect infusible fluoride levels, whereas adding sugar increased
the infusible fluoride in the first few minutes. In addition,
it was found that the critical step during the manufacturing process
affecting the percentage of infusible fluoride was ball rolling
rather than fermentation. Furthermore, intakes of high amounts
(>/=5 l/week) of certain tea may result in excess risks of
dental or skeletal fluorosis. Tea
lovers could be exposed to excess fluoride and may be at risk
of fluorosis.Journal of Exposure Science and Environmental
Epidemiology advance online publication, 4 April 2007; doi:10.1038/sj.jes.7500574.
PMID: 17410113 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17416376&query_hl=1&itool=pubmed_DocSum
J Chromatogr A. 2007 Mar 28; [Epub
ahead of print]
Trace analysis of total fluorine in human
blood using combustion ion chromatography for fluorine: A mass
balance approach for the determination of known and unknown organofluorine
compounds.
Miyake Y, Yamashita N, So MK, Rostkowski P, Taniyasu S, Lam
PK, Kannan K.
National Institute of Advanced Industrial Science and Technology
(AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan.
The number of perfluorochemicals (PFCs) that have been found
in biological and environmental matrices is increasing as analytical
standards and methods evolve. Perfluorooctanesulfonate (PFOS)
and perfluorooctanoate (PFOA) constitute only a fraction of the
total suite of PFCs found in environmental and biological matrices.
A robust method and approach is needed to evaluate the mass of
fluorinated compounds in biological matrices. In this study, we
developed a method to measure total fluorine (TF) and organic
fluorine (TOF) in human blood matrices using combustion ion chromatography
(CIC). Blood matrices (whole blood, serum, and plasma) were analyzed
in bulk to determine TF. An aliquot of the blood was also extracted
with organic solvents such as methyl-tert-butyl ether (MTBE) and
hexane, and organic and aqueous extracts were separated, to fractionate
organofluorines from inorganic fluorine. The organic layer was
analyzed for TF by CIC, and for known PFCs by high performance
liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). PFCs
measured by HPLC-MS/MS accounted for >80% of the TF in the
organic fraction. The aqueous fraction contained inorganic fluorine
and other non-extractable organofluorines. However,
in the bulk sample, fluoride and non-extractable organofluorines
accounted for >70% of the TF in blood samples from the general
population. In occupationally exposed individuals, known organofluorines
accounted for a major proportion of the TF. These results suggest
the existence of yet uncharacterized fluorine fraction in human
blood. Further studies are needed to characterize the
aqueous fraction that contains inorganic fluorine and non-extractable
forms of fluorine.
PMID: 17416376 [PubMed - as supplied by publisher]
Full paper at Science Direct
Ecological Modelling- Article in Press 2007 , Corrected Proof
Use of habitat-contamination spatial correlation
to determine when to perform a spatially explicit ecological risk
assessment
S.T. Purucker (a), C.J.E. Welsh (b), R.N. Stewart (b) and P.
Starzec (c)
a) U.S. Environmental Protection Agency,
960 College Station Road, Athens, GA 30605, USA
b) Department of Ecology and Evolutionary Biology, University
of Tennessee, Knoxville, TN 37996, USA
c) Swedish Geotechnical Institute, Chalmers Vasa, Göteborg,
Sweden
Received 3 October 2006; revised 21 December 2006; accepted 28
December 2006. Available online 28 March 2007.
Anthropogenic contamination is typically distributed heterogeneously
through space. This spatial structure can have different effects
on the cumulative doses of wildlife exposed to contamination within
the environment. These effects are accentuated when individual
organisms pursue different movement strategies, and movement strategies
can be affected by how individual organisms and species value
habitat. Habitat quality is often neglected when ecological risk
assessments are performed, despite evidence that inclusion of
a quantitative habitat measure can have a significant effect on
the overall exposure estimate. We couple an exposure model with
habitat data to examine the interactions between habitat preferences,
the spatial distribution of contamination, and the resulting impact
on dose estimates. Dose distributions are
constructed for pronghorn (Antilocapra americana) exposed
to fluoride when foraging on desert sagebrush. The results
show the magnitude of the difference between simulated doses when
foraging concentrations are positively or negatively correlated
with different spatial distributions of habitat preferences. Mean
estimated exposures obtained from non-spatial versus spatial methods
can vary by a factor greater than two, and variation within the
movement model, due to different habitat preferences, can vary
by an order of magnitude. Such differences in calculated exposures
can change a remediation decision from no-action to remediation,
or vice-versa, and impact the remedial design when cleanup is
required. In addition, information concerning which endpoint species
are more or less likely to be exposed to chemical contamination
in a given spatial setting can be used by stakeholders in the
endpoint selection process. Results presented here are generally
applicable to other situations where terrestrial wildlife is exposed
to chemical contaminants. These simple model
results demonstrate that examining the strength of the spatial
correlation between habitat preference and contaminant data can
be quickly used to determine when the implementation of a spatially
explicit ecological risk assessment is useful.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17316743&query_hl=151&itool=pubmed_docsum
Water Res. 2007 Apr;41(7):1534-42.
Epub 2007 Feb 21.
Treatment of high fluoride concentration
water by MgAl-CO(3) layered double hydroxides: Kinetic and equilibrium
studies.
Lv L, He J, Wei M, Evans DG, Zhou Z.
West Branch of Zhejiang University of Technology, 78 Jiu Hua
Da Dao, Ke Cheng District, Quzhou City, Zhejiang 324000, China;
State Key Laboratory of Chemical Resource Engineering, Beijing
University of Chemical Technology, Beijing 100029, China.
MgAl-CO(3) layered double hydroxides (LDHs) have been employed
to treat high fluoride concentration solution. The influences
of solution pH, initial fluoride concentration and other anions
in the solution were investigated by a series of batch experiments.
A marked decrease in the amount of adsorbed fluoride by LDHs is
observed with increasing pH. The extent of fluoride removal in
the presence of other anions decreases in the order HCO(3)(-)>Cl(-)>H(2)PO(4)(-)>SO(4)(2-).
The equilibrium isotherm for fluoride uptake corresponds closely
to the Langmuir-Freundlich (L-F) model. The maximum capacity of
LDHs for fluoride ions and the Gibbs free energy (DeltaG(0)) for
the defluoridation process were calculated to be 319.8+/-5.7mg/g
and -9.0+/-0.66kJ/mol, respectively. The negative value of DeltaG(0)
indicates the spontaneous nature of the treatment process. Four
kinetic models have been evaluated in order to attempt to fit
the experimental data, namely the pseudo-first order, the pseudo-second
order, the modified multiplex and the double exponential models.
It was found that the modified multiplex model, involving a rapid
first order step and a slow second order step most closely described
the kinetics. The activation energies for the two steps are 37.2+/-5.26
and 72.6+/-4.52kJ/mol, respectively, suggesting that the rapid
step is controlled by diffusion processes, whilst the second step
is controlled by the reaction of fluoride with the LDHs.
PMID: 17316743 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17193740&query_hl=1&itool=pubmed_DocSum
Rocz Panstw Zakl Hig. 2006;57(3):203-10.
[Fluoride content of soft drinks produced in Poland]
[Article in Polish]
Jedra M, Urbanek-Karlowska B, Gawarska H, Sawilska-Rautenstrauch
D.
Zaklad Badania Zywnosci i Przedmiotow Uzytku Panstwowy Zaklad
Higieny, 00-791 Warszawa.
Fluoride content of 81 commercial brands of soft drinks and bottled
waters were determined using potentiometric method with ion selective
electrode. In the beverages produced in the same factory fluoride
level were similar. The connection between elevation of fluoride
levels and ingredients of investigated products such as juice
or cola extract was not found. However, in
some samples of ice tea drinks containing the tea extract fluoride
levels might have been raised up to 1.28 mg/l. Fluoride
contents of beverages from 28 producers ranged from 0.01 to 0.30
mg/l and only from 4 producers up to 0.60 mg/l. The highest level
of fluoride (1.39 mg/l) has been determined in one sample of mineral
water. In conclusion, ice tea beverages
and certain mineral water, made and sold in Poland, may constitute
an important source of fluoride in diet. Their consumption, particularly
in case of children, must be controlled.
PMID: 17193740 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17405323&query_hl=1&itool=pubmed_DocSum
J Environ Biol. 2006 Oct;27(4):633-7.
Groundwater quality--assessment on Anekal Taluk, Bangalore
Urban district, India.
Prakash KL, Somashekar RK.
Department of Environmental Science, Bangalore University, Bangalore-
560 056, India.
Water as a resource, basic amenity and universal solvent is shared
by population. The physicochemical and biological quality study
of Anekal Taluk has been taken up to evaluate its suitability
for potable purposes. 1026 water samples were collected from bore
well, hand pumps of 272 villages covering in Anekal Taluk. The
quality of groundwater has been made through the analysis of pH,
colour, electrical conductivity, turbidity, total dissolved solids,
alkalinity, chlorides, total hardness, calcium, fluoride, nitrate,
sulphate, iron and E. coli. The quality of groundwater assessed
in the study area is discussed in detail.
PMID: 17405323 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17420092&query_hl=1&itool=pubmed_docsum
J Hazard Mater. 2007 Mar 12; [Epub
ahead of print]
Influence of anionic species on uranium separation from
acid mine water using strong base resins.
Ladeira AC, Goncalves CR.
Center for Development of Nuclear Technology, Rua Prof. Mario
Werneck s/n, 30123970, Belo Horizonte, MG, Brazil.
The presence of uranium and other elements in high concentrations
in acid mine drainage at Pocos de Caldas Uranium Mine (Brazil)
is a matter of concern. The acid water pH is around 2.7, the uranium
concentration is in the range of 6-14mgL(-1), sulfate concentration
near 1400mgL(-1), fluoride 140mgL(-1) and iron 180mgL(-1). In
this solution, where sulfate is present in elevated concentrations,
uranium is basically in the form of UO(2)(SO(4))(3)(4-). This
study investigated the separation of uranium from the other anions
present in the acid water under batch and column mode using ion
exchange technique. The pH studied was 2.7 and 3.9. Two strong
base anionic resins were tested. The influence of ions, commonly
found in acid waters like sulfate and fluoride, on ion exchange
process was also assessed. Equilibrium studies were carried out
to determine the maximum adsorption capacities of the resins.
The resins showed a significant capacity for uranium uptake which
varied from 66 to 108mgg(-1) for IRA 910U and 53 to 79mgg(-1)
for Dowex A. The results also showed that SO(4)(2-) is the most
interfering ion and it had a deleterious effect on the recovery
in the pH range studied. Fluoride did not affect uranium removal.
PMID: 17420092 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17286173&query_hl=152&itool=pubmed_docsum
Environ Monit Assess. 2007 Feb 8;
[Epub ahead of print]
Air quality at a snowmobile staging area and snow chemistry
on and off trail in a Rocky Mountain subalpine forest, Snowy Range,
Wyoming.
Musselman RC, Korfmacher JL.
Rocky Mountain Research Station, USDA Forest Service, 240 West
Prospect Road, Fort Collins, CO, 80526-2098, USA, rmusselman@fs.fed.us.
A study was begun in the winter of 2000-2001 and continued through
the winter of 2001-2002 to examine air quality at the Green Rock
snowmobile staging area at 2,985 m elevation in the Snowy Range
of Wyoming. The study was designed to evaluate the effects of
winter recreation snowmobile activity on air quality at this high
elevation site by measuring levels of nitrogen oxides (NO( x ),
NO), carbon monoxide (CO), ozone (O(3)) and particulate matter
(PM(10) mass). Snowmobile numbers were higher weekends than weekdays,
but numbers were difficult to quantify with an infrared sensor.
Nitrogen oxides and carbon monoxide were significantly higher
weekends than weekdays. Ozone and particulate matter were not
significantly different during the weekend compared to weekdays.
Air quality data during the summer was also compared to the winter
data. Carbon monoxide levels at the site were significantly higher
during the winter than during the summer. Nitrogen oxides and
particulates were significantly higher during the summer compared
to winter. Nevertheless, air pollutants were well dispersed and
diluted by strong winds common at the site, and it appears that
snowmobile emissions did not have a significant impact on air
quality at this high elevation ecosystem. Pollutant concentrations
were generally low both winter and summer. In a separate study,
water chemistry and snow density were measured from snow samples
collected on and adjacent to a snowmobile trail. Snow
on the trail was significantly denser and significantly more acidic
with significantly higher concentrations of sodium, ammonium,
calcium, magnesium, fluoride, and sulfate than in snow off the
trail. Snowmobile activity had no effect on nitrate levels
in snow.
PMID: 17286173 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17379355&query_hl=1&itool=pubmed_DocSum
J Contam Hydrol. 2007 Feb 15; [Epub
ahead of print]
The presence of vanadium in groundwater of southeastern
extreme the pampean region Argentina Relationship with other chemical
elements.
Fiorentino CE, Paoloni JD, Sequeira ME, Arosteguy P.
Dpto. de Agronomia - Univ. Nac. del Sur. San Andres 850, (8000)
Bahia Blanca, Argentina.
Changes in the quality of groundwater resources are related to
the presence and concentration of contaminants, especially trace
elements such as arsenic, boron, fluoride and vanadium. Vanadium
is a rare element naturally abundant, generally found in combination
with other elements. Vanadium pentoxide is known to have aneugenic
effects. Thus, a study was carried out to assess the presence
of vanadium in the groundwater of the southeastern pampean region
of Argentina, which constitutes the main water supply for the
local population. Statistical and correlational analyses were
applied to identify possible interrelationships between vanadium
and another chemical elements. Vanadium was found in all groundwater
samples. The minimum and maximum vanadium concentrations found
were 0.05 mg/l and 2.47 mg/l, respectively. Vanadium
is significantly correlated with other trace elements such as
arsenic, fluoride and boron. The interrelationship between
vanadium and the presence of volcanic glass in sediments is not
significant as expected.
PMID: 17379355 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17157383&query_hl=1&itool=pubmed_DocSum
Environ Int. 2007 Apr;33(3):302-8.
Epub 2006 Dec 8.
Total fluoride in Guangdong soil profiles, China: spatial
distribution and vertical variation.
Zhu L, Zhang HH, Xia B, Xu DR.
CAS Key Laboratory of Marginal Sea Geology, Guangzhou Institute
of Geochemistry, Chinese Academic of Sciences, 510640, China.
A total of 260 soil profiles were reported to investigate the
fluoride distribution and vertical variation in Guangdong province.
The soil fluoride contents followed an approximately lognormal
distribution. Although the soil fluoride geometric mean concentration
of 407 mg/kg is lower than that of China,
its content varied from 87 to 2860 mg/kg. An upper baseline
concentration of 688 mg/kg was estimated for surface soils. In
A-, B-, and C-horizon soil fluoride spatial distribution presented
similar patterns that high fluoride concentration mainly located
in limestone, purple shale, and sandshale areas, indicated that
soil fluoride spatial distribution was primarily dependent on
the regional bedrock properties rather than anthropogenic inputs.
From A- to C- horizon soil fluoride geometric mean concentration
had an increasing tendency of 407, 448, and 465 mg/kg. This vertical
variation was the result of the intensive eluviation under the
subtropical hydrothermal condition, and had closely related with
soil properties, such as lower organic matters and clay content
variations. Moreover, the soil degradation
and erosion was also an important pathway of soil fluoride movement,
as a result the soil fluoride exported into surface and groundwaters
would reach about 4.1x10(4) t year-1 in the study area.
PMID: 17157383 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17377848&query_hl=1&itool=pubmed_DocSum
Environ Geochem Health. 2007 Mar
22; [Epub ahead of print]
Fluoride in Ceylon tea and its implications to dental
health.
Chandrajith R, Abeypala U, Dissanayake CB, Tobschall HJ.
Department of Geology, University of Peradeniya, Peradeniya,
Sri Lanka.
The purpose of this study was to assess the fluoride content
of Ceylon Tea, which is a popular beverage throughout the world.
The fluoride content of tea infusions prepared from different
grades of tea leaves collected from different parts of the tea-growing
regions (25 samples) of Sri Lanka was measured using a fluoride-selective
electrode. Fluoride leaching was found to
vary from 0.32 to 1.69 mg F/l, but there were no significant
differences in terms of fluoride leaching between tea from different
tea-growing regions or between tea of different grades. Dental
fluorosis is widespread throughout the dry zone of Sri Lanka,
and drinking water has traditionally been considered to be the
main contributory factor to the development of fluorosis. However,
diet, the consumption of tea in particular, may also contribute
to the manifestation of dental diseases.
PMID: 17377848 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17363157&query_hl=1&itool=pubmed_DocSum
J Hazard Mater. 2007 Feb 2; [Epub
ahead of print]
Removal of excess fluoride from water using waste residue
from alum manufacturing process.
Nigussie W, Zewge F, Chandravanshi BS.
Environmental Science Program, Faculty of Science, Addis Ababa
University, P.O. Box 1176, Addis Ababa, Ethiopia.
The ability of waste residue, generated from alum manufacturing
process, to remove fluoride ion from water has been investigated.
Series of batch adsorption experiments were carried out to assess
parameters that influence the adsorption process. The factors
investigated include the effect of contact time, adsorbent dose,
thermal pretreatment of the adsorbent, neutralization of the adsorbent,
initial fluoride concentration, pH of the solution and effect
of co-existing anions. Results showed that Adsorption of fluoride
is fairly rapid in first 5min and thereafter increases slowly
to reach the equilibrium in about 1h. The removal efficiency of
fluoride was increased with adsorbent dosage. About 85% removal
efficiency was obtained within 1h at an optimum adsorbent dose
of 16g/L for initial fluoride concentration of 10mg/L. Heat treatment
and surface neutralization of the adsorbent did not improve the
fluoride removal capacity and efficiency. The amount of fluoride
adsorbed increased with increasing initial fluoride concentration.
The percentage of fluoride removal remains nearly constant within
the pH range of 3-8. The adsorption data at ambient pH were well
fitted to the Dubinin-Radushkevick (D-R) isotherm model with a
capacity of 332.5mg/g of the adsorbent. The adsorption kinetic
was found to follow a pseudo-second-order rate equation with an
average rate constant of 2.25gmin(-1)mg(-1). The presence of bicarbonate
at higher concentrations (100-500mg/L) decreased the fluoride
removal efficiency while other anions (chloride, sulfate, phosphate
and nitrate) have no significant effect within the concentration
range tested. The overall result shows that the waste residue
is efficient defluoridating material.
PMID: 17363157 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17161460&query_hl=1&itool=pubmed_DocSum
Environ Int. 2007 May;33(4):583-8. Epub 2006
Dec 8.
Lolium perenne as a biomonitor of atmospheric levels
of fluoride.
Rey-Asensio A, Carballeira A.
Ecologia, Facultad de Biologia, Univ. Santiago de Compostela,
15706 Santiago de Compostela, Spain.
The aim of the present study was to develop a standardised protocol
for the use of Lolium perenne cultures to
biomonitor the surroundings of an aluminium smelter. Five
ecological stations, which corresponded to air quality network
monitoring sites pertaining to the smelter, were selected for
study. Cultures of L. perenne (one at each site) were exposed
for approximately 28 days, at different times between August 1999
and October 2000. At the end of the exposure periods, the fluoride
concentrations in the cultures were determined. The
concentrations of fluoride determined in the L. perenne cultures
varied from 4.32 mug g(-1) to 912.22 mug g(-1) and followed a
similar trend to concentrations of atmospheric fluoride. However,
a wider range of fluoride concentration was observed in the L.
perenne cultures than in the air surrounding the smelter. The
background levels of fluoride in L. perenne cultures were also
calculated, thereby allowing classification of fluoride air pollution
in the area under study.
PMID: 17161460 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17289116&query_hl=1&itool=pubmed_DocSum
Sci Total Environ. 2007 Mar 15;374(2-3):399-407.
Epub 2007 Feb 6.
Effects of initial climatic conditions on growth and
accumulation of fluoride and nitrogen in leaves of two tropical
tree species exposed to industrial air pollution.
Furlan CM, Domingos M, Salatino A.
Departamento de Botanica, Instituto de Biociencias, Universidade
de Sao Paulo, CP 11461, 05422-970, Sao Paulo, SP, Brazil. furlancm@yahoo.com.br
Saplings of Tibouchina pulchra and Psidium guajava, cultivated
under standardized soil conditions, were placed in two sites at
Cubatao (state of Sao Paulo, southeast Brazil) to study the effects
of air pollution on growth, biomass allocation and foliar nitrogen
and fluoride concentrations. Thirty-six potted plants were maintained
over two periods of one year (Jul/00 to Jun/01; Dec/00 to Nov/01)
at each of two experimental sites with distinct levels of air
pollution: Piloes River Valley (PV) with vegetation virtually
unaffected by air pollution; and Mogi River Valley (MV) severely
affected by pollutants released mainly by chemical, fertilizer,
iron and steel industries. For both species, saplings growing
at MV showed alterations of growth and biomass allocation, as
well as increased leaf concentrations of nitrogen and fluoride.
Comparing both experimental periods, the one starting in winter
(the driest season in Southeastern Brazil) seemed to affect the
saplings more severely, the differences of the measured parameters
between MV and PV being higher than in the second period. Multivariate
analysis revealed two groups of data: one representing the MV
and the other the PV saplings. For both species, saplings growing
at MV showed differences in chemical composition, growth and biomass
allocation, compared with the PV saplings. The results suggested
that seasonal conditions of the first months of sapling exposure
(summer or winter) modulate the intensity of responses to pollution
stress.
PMID: 17289116 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17212473&query_hl=1&itool=pubmed_DocSum
Chem Rev. 2007 Jan;107(1):114-32.
Natural and synthetic fluoride carbonates.
NO ABSTRACT AVAILABLE
Grice JD, Maisonneuve V, Leblanc M.
Canadian Museum of Nature, P.O. Box 3443, Stn D, Ottawa, Ontario
K1P 6P4, Canada.
PMID: 17212473 [PubMed]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17197412&query_hl=1&itool=pubmed_DocSum
J Am Dent Assoc. 2007 Jan;138(1):132
For the dental patient: infants, formula and fluoride.
NO ABSTRACT AVAILABLE
ADA Division of Communications.
American Dental Association, USA.
PMID: 17197412 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17295116&query_hl=154&itool=pubmed_docsum
Environ Monit Assess. 2007 Feb
13; [Epub ahead of print]
Hydro-chemical Survey of Groundwater of Hisar City and
Assessment of Defluoridation Methods Used in India.
Ravindra K, Garg VK.
Department of Environmental Science and Engineering, Guru Jambheshwar
University of Science and Technology, Hisar, 125001, India.
Ground water quality of Hisar city was assessed for its suitability
for drinking purposes. Samples collected from the Bore-wells (forms
a part of municipal water supply) and handpumps (direct consumption)
were analyzed for the various physico-chemical parameters including
pH, electrical conductivity, total dissolved salts, total hardness,
total alkalinity, sodium, potassium, calcium, magnesium, carbonate,
bicarbonate, chloride and sulfate. The concentrations of magnesium,
sodium, potassium, sulfate and especially of chloride were found
moderately higher than the WHO standards for the drinking water.
Further a comparison of fluoride (F(-)) levels in groundwater
of various cities and towns of Haryana state was performed. The
relatively higher concentrations of F(-) in groundwater of Haryana
raise the risk of fluorosis and hence groundwater must be used
with proper treatment. Promising defluoridation methods using
locally available materials and technologies are discussed for
the prevention and control of fluorosis. Data were assessed statistically
to find the suitable markers of ground water quality as an aid
to monitoring groundwater quality.
PMID: 17295116 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17234235&query_hl=157&itool=pubmed_docsum
Water Res. 2007 Feb;41(4):810-8.
Epub 2007 Jan 17.
Calcium fluoride recovery from fluoride wastewater in
a fluidized bed reactor.
Aldaco R, Garea A, Irabien A.
Departamento de Ingenieria Quimica y Quimica Inorganica, Universidad
de Cantabria, ETSIIyT, Avda. los Castros s/n, 39005 Santander,
Spain. aldacor@unican.es
In order to contribute to better resource efficiency and industrial
waste management leading to a sustainable production and consumption
pattern new processes must be developed, which should be operated
in such a way that waste production is reduced or avoided. Fluoride
removal by precipitation generates huge amounts of a water rich
sludge. Calcium fluoride is not recovered from the waste streams
and it is not recycled due to the high water content and the low
quality of the sludge. Crystallization process in a fluidized
bed reactor (FBR) appears as an alternative technology to the
conventional chemical precipitation process. In the crystallization
process in a FBR silica sand is usually used as seed material,
however silica is a deleterious impurity because it causes losses
in the yield of HF and its content should be less than 1%. In
this paper, granular calcite has been used as seed material in
order to obtain synthetic calcium fluoride. According to the composition
(CaF(2)>97%, SiO(2)<1%), the synthetic calcium fluoride
from the crystallization process in a FBR is able to be recycled
as raw material for the manufacture of hydrofluoric acid leading
to a reduction of raw materials consumption. The crystallization
process in a FBR to remove fluoride from industrial wastewaters
contributes to an environmental friendly production, because it
allows to reduce the waste production as well as to increase the
recovery of materials.
PMID: 17234235 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17305321&query_hl=1&itool=pubmed_DocSum
J Phys Chem A. 2007 Mar 15;111(10):1852-9.
Epub 2007 Feb 17.
Kinetics of sulfur oxide, sulfur fluoride, and sulfur
oxyfluoride anions with atomic species at 298 and 500 K.
Midey AJ, Viggiano AA.
Air Force Research Laboratory, Space Vehicles Directorate, 29
Randolph Road, Hanscom Air Force Base, Massachusetts 01731-3010,
USA. Anthony.Midey@hanscom.af.mil
The rate constants and product-ion branching ratios for the reactions
of sulfur dioxide (SO2-), sulfur fluoride (SFn-), and sulfur oxyfluoride
anions (SOxFy-) with H, H2, N, N2, NO, and O have been measured
in a selected-ion flow tube (SIFT). H atoms were generated through
a microwave discharge on a H2/He mixture, whereas O atoms were
created via N atoms titrated with NO, where the N had been created
by a microwave discharge on N2. None of the ions reacted with
H2, N2 or NO; thus, the rate constants are <1 x 10(-12) cm3
s-1. SOxFy- ions react with H by only fluorine-atom abstraction
to form HF at 298 and 500 K. Successive F-atom removal does not
occur at either temperature, and the rate constants show no temperature
dependence over this limited range. SO2- and F- undergo associative
detachment with H to form a neutral molecule and an electron.
Theoretical calculations of the structures and energetics of HSO2-
isomers were performed and showed that structural differences
between the ionic and neutral HSO2 species can account for at
least part of the reactivity limitations in the SO2- + H reaction.
All of the SOxFy- ions react with O; however, only SO2- reacts
with both N and O. SOxFy- reactions with N (SO2- excluded) have
a rate constant limit of <1 x 10(-11) cm3 s-1. The rate constants
for the SOxFy- reactions with H and O are < or =25% of the
collision rate constant, as seen previously in the reactions of
these ions with O3, consistent with a kinetic bottleneck limiting
the reactivity. The only exceptions are the reactions of SO2-
with N and O, which are much more efficient. Three pathways were
observed with O atoms: F-atom exchange in the reactant ion, F-
exchange in the reactant ion, and charge transfer to the O atom.
No associative detachment was observed in the N- and O-atom reactions.
PMID: 17305321 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17410214&query_hl=166&itool=pubmed_docsum
N Z Vet J. 2007 Apr;55(2):77-80.
The effect of a temporal change in ingestion rates of
fluorine (F) in soil on the concentration of F in serum and bone
of young sheep.
Grace ND, Loganathan P, Hedley MJ.
AgResearch Limited, Grasslands Research Centre, Private Bag 11008,
Palmerston North, New Zealand. neville.grace@agresearch.co.nz
AIM: To determine the changes in concentrations of fluorine (F)
in serum and bone of young sheep given a high intake of F, as
F in soil, followed by a low intake of F, to simulate the varying
intakes experienced by grazing sheep.
METHODS: Sixty autumn-born, weaned, mixed-sex lambs were randomly
divided into two groups (n=30). One group (Control) was fed a
low-F (12 mg/kg dry matter; DM) lucerne/ grain diet for 345 days,
while the other group (High soil-F) was fed a high-F (224 mg/kg
DM) lucerne/grain diet containing 10% soil for 94 days and then
a low-F diet for a further 251 days. Blood samples were collected
on Days 1, 32, 94, 108, 153, 214, 280 and 345, to determine concentrations
of F in serum. Groups of five or six animals from each group were
killed on Days 1, 94, 153, 214, 280 and 345, to collect radii
and humeri for determination of F content. The sheep were weighed
at about 6-8-weekly intervals.
RESULTS: Initial liveweight of the sheep was 22.1 (standard error
(SE) 1.12) kg and the mean liveweight gains were 270 (SE 22.1)
and 170 (SE 12.4) g/day from Days 1 to 94 and 95 to 330, respectively.
The mean initial (Day 1) concentration of F in serum was 0.03
(SE 0.005) mg/L, and this changed very little for animals on the
low-F diet. In sheep on the high soil-F diet, the concentration
of F in serum reached 0.38 (SE 0.021) mg/L at Day 94 but after
being placed on the low-F diet concentrations decreased to 0.04
(SE 0.006) mg/L after 14 days (Day 108) and then remained at about
this low level for the remainder of the duration of the study.
The mean concentrations of F in the humerus and radius of the
lambs at Day 1 were 161 (SE 19.4) and 159 (SE 20.4) mg/kg DM,
respectively, which increased to 2,784 (SE 80.6) and 1,805 (SE
51.5) mg/kg DM, respectively, at Day 94 in lambs fed the high
soil-F diet, then decreased to 1,075 (SE 58.1) and 1,064 (SE 61.6)
mg/kg DM at Day 153, and then progressively increased to 1,669
(SE 57.7) and 1,312 (SE 30.8) mg/kg DM at Day 345.
CONCLUSIONS: The ingestion of F in soil
by sheep markedly increased their concentrations of F in serum
and bone, but when the soil was removed and they were fed a low-F
diet, concentrations of F in serum decreased to baseline levels
within 14 days while concentrations in the bone only decreased
to 60-70% of the peak concentration, indicating that some of the
F in bone was remobilised.
PMID: 17410214 [PubMed - in process]
PubMed Abstract - BMJ. 2007 Oct 27;335(7625):841.
Comment on: BMJ. 2007 Oct 6;335(7622):699-702.
Fluoridation: Addressing the arguments, by Baldwin of Bewdley .
PubMed Abstract - BMJ. 2007 Oct 27;335(7625):840.
Comment on: BMJ. 2007 Oct 6;335(7622):699-702.
Fluoridation: The Department of Health's view, by Cockcroft B, Donaldson L.
PubMed Abstract - BMJ. 2007 Oct 27;335(7625):840-1.
Comment on:
BMJ. 2007 Oct 6;335(7622):699-702.
Fluoridation: Interpreting the Newcastle fluoride bioavailability study, by Holgate ST, Sheldon TA.