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2003 Fluoride Abstracts. Part 2.
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2003 Reports
Opinion of the Scientific Committee on Animal Nutrition on Undesirable Substances in Feed.
See section on Fluorine (pages 15-18).
European Commission, Health & Consumer Protection Directorate-General. (Adopted on 20 February 2003, updated on 25 April 2003). - also available at
http://europa.eu.int/comm/food/fs/sc/scan/out126_bis_en.pdf
Report of the Scientific Committee on Food on the Revision of Essential Requirements of Infant Formulae and Follow-on Formulae. European Commission, Health and Consumer Protection Directorate-General, Scientific Committee on Food. SCF/CS/NUT/IF/65. Final. 18 May 2003.
See excerpts at bottom of page
TRUTH DECAY Challenging New Labour's propaganda on water fluoridation Or A few things you might want to know about FLUORIDE before Tony Blair adds it to your drinking waterby Spencer Fitz-Gibbon
Second edition, revised August 2003
Green Party of England & Wales
1a Waterlow Road, London N19 5NJ.
Tel 020 7561 0282. Fax 020 7272 6653.
Email: media@greenparty.org.
Effects of air pollution on agricultural crops -- Revised edition. Order No. 85-002; Printed June, 2003
Griffiths H
Ontario. Ministry of Agriculture & Food, Guelph, (Ontario).
Full free report available at:
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-74912003000300005&lng=en&nrm=isoPesqui Odontol Bras. 2003 Jul-Sep;17(3):223-7. Epub 2003 Dec 16.
Fluorine content of several brands of chocolate bars and chocolate cookies found in Brazil.
Buzalaf MA, Granjeiro JM, Cardoso VE, da Silva TL, Olympio KP.
Department of Biological Sciences, University of Sao Paulo, Brazil.
Chocolate bars and chocolate cookies are foodstuffs highly appreciated by children. The possibility of having fluorine (F) among their components, associated with an excessive consumption, may make them decisive contributors to the total daily F intake. Thus, they could participate in the establishment of dental fluorosis. The aim of this study was to analyze the fluorine concentration [F] of the chocolates bars (CB) Baton, Confeti, Garoto Ball, Kinder Ovo, M&M s, Milkybar, Nescau, Nescau Ball, Surpresa, Surpresa Bichos, Tortuguita; and of the chocolate cookies (CC) Danyt s, Hipop , Nescau, Passatempo, Pokemon, S tio do Pica-Pau Amarelo and Trakinas. Samples were purchased in Bauru, Sao Paulo, Brazil. Three grams of each product were previously ashed at 525 C (CB and cookies fillings) and at 550 C (cookies dough), during 4 hours. Fluorine was separated from the ash by hexamethyldisiloxane (HMDS)-facilitated diffusion. Fluorine analysis was carried out with the specific electrode. Mean [F]s SD and amplitude (unit mg/g) were: CB = 0.30 0.45 (0.07 - 1.60, n = 12) and CC = 1.08 2.64 (0.04 - 7.10, n = 7). It was concluded that some of the analyzed foods may be important contributors to the total daily F intake. As for the product that had the highest [F] (Danyt s), when only 3 units are consumed just once a day, they may supply up to 40% of the maximum recommended daily F intake (0.07 mg/kg body weight) for a 2-year-old child (12 kg). The [F] in these products should be informed on their labels.
PMID: 14762499 [PubMed - in process]Indian J Environ Health. 2003 Oct;45(4):285-8.
Pyroclastic fluoride in ground waters in some parts of Tadpatri Taluk, Anantapur district, Andhra Pradesh.
Reddy NB, Prasad KS.
Dept of Geology, S V University, Tirupati.
Fluorosis is a disease affecting the teeth and bones and caused by excessive ingestion of fluoride through drinking water. Fluoride concentration in ground water samples of the study area varies from 1.2 to 2.1 ppm., which is much above the permissible limit. The probable source of fluoride in ground water is fluoride bearing minerals like apatite, micas and clay minerals etc., present in the country rocks like shales and pyroclastic materials of the study area. The sample survey is carried out to know the incidence of fluorosis in this area which reveals that more than 43% of the inhabitants are affected by dental fluorosis and 0.4% by skeletal fluorosis.
PMID: 15527021 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15527028Indian J Environ Health. 2003 Oct;45(4):325-34.
Environmental pollution in rural areas of Orissa state due to industrial emissions--with special reference to fluoride.
Mukherjee AK, Ravichandran B, Bhattacharya SK, Ahmed S, Roy SK, Thakur S, Roychowdhury A, Saiyed HN.
Regional Occupational Health Center (Eastern), Calcutta.
Angul - Talcher belt in Central Orissa, having a number of industries contributing to a great extent to deteriorate the air quality of the surrounding villages. Previous reports showed higher SPM, SO2, NO, levels in air and prevalence of respiratory illness, skin and teeth disorders among village population. Higher ground water fluoride, urine and serum fluoride among the cattle were also reported in some villages. Present study reports SPM, SO2, NOx and Fluorides (gaseous and Particulate) in ambient air around aluminium smelter during February and August 1996. High volume sampling technique for SPM and the standard colorimetric methods (BIS) for analyses of SO2 and NOx were adopted. Fluoride in air and water were estimated by standard fluoride ion selective electrode method. Higher SPM, SO2 and NOx values than prescribed CPCB standard were obtained in February. Gaseous fluoride in village air were varied between, 1.66 - 7.64 mg/m3 in February and 1.11 - 22.75 mg/m3 in August, whereas particulate fluoride ranged between, 0.054 - 19.61 mg/m3. Water sources of the villages near the smelter showed fluoride values above permissible limit. The study indicated higher fluoride pollution in air and water of the surrounding villages.
PMID: 15527028 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15248664J Environ Biol. 2003 Oct;24(4):465-70.
Dental fluorosis in bovine of Nayagarh district of Orissa.
Maiti SK, Das PK, Ray SK.Dept. of Veterinary Medicine, College of Veterinary Science and Animal Husbandry, Anjora, Durg-491 011, Chhattisgarh, India.
Chronic fluoride toxicity in the form of dental fluorosis was observed in cattle from nine (9) villages under two (2) blocks of Nayagarh district of Orissa. Out of 1117 cattle, 221 (18.09%) showed the signs of dental fluorosis. In all affected villages, the prevalence of dental fluorosis in calves (< 1 year age) was greater than adults. There was significant difference in prevalence in respect to age. The commonly observed signs of dental fluorosis were brown discoloration, mottling, attrition or uneven wearing of teeth with or without pitting. None of the affected animals showed characteristic signs of osteofluorosis. The mean serum and urine fluoride concentration of affected animals were significantly (P < 0.05) higher than those of control animals. Fluoride levels (mean) of ground water and surface water in two blocks were 1.30 +/- 0.16 ppm, 0. 66 +/- 0.08 ppm and 1.12 +/- 0.19 ppm, 0. 48 +/- 0.05 ppm respectively. The fluoride content of grass samples of affected and control (non-endemic) area was comparable. There was a highly positive correlation (r = + 0.664) between prevalence of dental fluorosis and fluoride content of ground water. It was concluded that fluoride intake through the water especially ground water contributed to the development of fluorosis in cattle.PMID: 15248664 [PubMed - in process]
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15527020Indian J Environ Health. 2003 Oct;45(4):281-4.
Mapping of fluoride endemic areas and correlation studies of fluoride with other quality parameters of drinking water of Veppanapalli block of Dharmapuri district in Tamil Nadu.
Karthikeyan G, Sundarraj AS, Elango KP.
Department of Chemistry, Gandhigram Rural Institute (Deemed University), Gandhigram, India. drg_karthikeyan@rediffmail.com
193 drinking water samples from water sources of 27 panchayats of Veppanapalli block of Dharmapuri district of Tamil Nadu were analysed for chemical quality parameters. Based on the fluoride content of the water sources, fluoride maps differentiating regions with high / low fluoride levels were prepared using Isopleth mapping technique. The interdependence among the important chemical quality parameters were assessed using correlation studies. The experimental results of the application of linear and multiple regression equations on the influence of hardness, alkalinity, total dissolved solids and pH on fluoride are discussed.
PMID: 15527020 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14963901Wei Sheng Yan Jiu. 2003 Nov;32(6):553-5.
[Study on the defluoridation of drinking water with model-La cation exchange resin]
[Article in Chinese]Huang M, Lu C.
School of Public Health, Nanhua University, Hengyang 421001, China.
Model-La cation exchange resin was transformed from strong acid cation exchange resin, which was used for the defluoridation of drinking water. The 001 x 7 strong acid cation exchange resin was transformed into model-La cation exchange by soaking in the La(NO3)3 solution. The F- in the water was removed by model-La cation exchange resin under the optimum condition because it was combined into fluoride with the La3+ in the model-La cation exchange resin. The used resin was regenerated with the La(NO3)3 solution and was used to defluoridate many times. The optimum conditions of transform and defluoridation and regeneration were d(rasin) = 0.315-0.600 mm, V(rasin):V(regeneration) = 1:6, t(transform) = 48 h, T = 298.16 K(25 degrees C). The defluoridation capacity was 5.60 mg/g in column test, and 4.08 mg/g in batch test. The model-La cation exchange resin could be used for defluoridation for 8 times. The results suggest that the model-La cation exchange resin is a novel material of defluoridation. This method is easy to master and the pH value of the solution doesn't need to be regenerated that the cost of defluoridation can be reduced significantly and it can be used for a long time.
PMID: 14963901 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14740986&dopt=Abstract
Environ Geochem Health. 2003 Dec;25(4):421-31.
Distribution and risk assessment of fluoride in drinking water in the west plain region of Jilin province, China.
Bo Z, Mei H, Yongsheng Z, Xueyu L, Xuelin Z, Jun D.
College of Environment and Resource, Jilin University, China.
The west plain region of Jilin province of northeast China is one of the typical endemic fluorosis areas caused by drinking water for many years. Investigations of hydrogeological and ecoenvironmental conditions as well as endemic fluorosis were conducted in 1998. Results show that the ground water, especially, the water in the unconfined aquifer is the main source of drinking water for local residents. The fluoride concentration in groundwater in the unconfined aquifers is higher than that in the confined aquifer in the west plain of Jilin province. The fluoride concentration in the unconfined aquifer can be used to classify the plain into fluoride deficient area, optimum area and excess area, which trend from west to east. High fluoride (>1.0 mg L(-1)) in drinking water resulted in dental and skeletal fluorosis in local residents (children and pregnant women). There exists a positive correlation between fluoride concentration in the drinking water and the morbidities of endemic fluorosis disease (r1 = 0.781, r2 = 0.872). Health risks associated with fluoride concentration in drinking water are assessed. It has been determined that fluoride concentration in excess of 1.0 mg L(-1) exposes residents to high health risks based on risk identification. The study area is classified into five health risk classes as shown in Figure 4. The risk indexes of this area more than 1.0 are accounted for 68% of the total west plain region.
PMID: 14740986 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14740989&dopt=AbstractEnviron Geochem Health. 2003 Dec;25(4):475-81.
Potential fluoride contamination in the drinking water of Naranji area, NorthWest Frontier Province, Pakistan.
Shah MT, Danishwar S.
National Centre of Excellence in Geology, University of Peshawar, Pakistan. tahir_shah72@hotmail.com
The drinking water of Naranji village and surrounding areas of the NorthWest Frontier Province (NWFP), Pakistan, was analyzed for its fluoride content. The fluoride content of water samples from the springs in the Naranji village goes up to 13.52 mg kg(-1), which exceeds the permissible limit (1.5 mg kg(-1)) set by the World Health Organization (WHO). This study explores the source of fluoride contamination and attributes it to the alkaline rocks of the Ambela granitic complex and the Koga complex. The low-lying areas towards the south have a fluoride content within the permissible limit. The Naranji area therefore needs urgent remedial measures.PMID: 14740989 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14702764&dopt=AbstractN Y State Dent J. 2003 Nov;69(9):34-7.
A Victorian physician ahead of his time. The story of fluorine advocate Sir James Crichton-Browne.
Ring ME.
Sir James Crichton-Browne, one of England's most renowned psychiatrists, whose career spanned two centuries, had very strong feelings about the need to secure proper dental care for all the children of his country. He translated these feelings into action when he advocated that fluorine be added to the diets of pregnant women and children. And this was almost a half-century before definitive research showed the value of fluorine as a preventive of caries.
Publication Types:
• Biography
• Historical ArticlePersonal Name as Subject:
• Crichton-Browne J
PMID: 14702764 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14740990&dopt=AbstractEnviron Geochem Health. 2003 Dec;25(4):483-90.
Fluoride content in bones of Adelie penguins and environmental media in Antarctica.
Xie Z, Sun L.
School of Earth and Space Sciences, Institute of Polar Environment, University of Science and Technology of China, Hefei, Anhui 230026, PR China.
Fluoride (F) distribution and its effects (fluorosis) were investigated in Antarctica. Droppings (L) excreta selected of aquatic birds, lake water, soil and moss (Polytrichum alpinum) showed a high F concentration. Although bones of Adelie penguin (Pygiscelis adeliae) and skua (Catharacta maccormicki) showed exceptionally very high F concentration in the range of 832 to 7187 mg kg(-1), their radiographs did not show any evidence of skeletal fluorosis. The possible reason and geochemical aspects of F in Antarctica region are discussed.PMID: 14740990 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14655903&dopt=AbstractArch Environ Health. 2003 Apr;58(4):229-32.
Pleural mesothelioma cases in Biancavilla are related to a new fluoro-edenite fibrous amphibole.
Comba P, Gianfagna A, Paoletti L.
Higher Institute of Health, Rome, Italy.A cluster of deaths from pleural mesothelioma was previously reported for Biancavilla, Italy, a city in eastern Sicily. An environmental survey suggested that the stone quarries located southeast of the city might be a source of asbestos exposure. The materials extracted from the quarries, used widely in the local building industry, contain large quantities of a fibrous amphibole that was initially referred to as an anomalous intermediate phase of sodium- and fluorine-rich tremolite-actinolite. A subsequent crystal chemistry investigation identified the mineral as fluoro-edenite, a new end-member of the edenite --> fluoro-edenite series. The material is very similar in morphology and composition to the minerals of the tremolite-actinolite series. To the authors' knowledge, fluoro-edenite becomes the 3rd mineral fiber (along with erionite and winchite), not yet classified as asbestos, with a demonstrable mesotheliomatogenous action in humans.
PMID: 14655903 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14609659&dopt=AbstractForensic Sci Int. 2003 Nov 26;137(2-3):209-14.
Bone as a biomarker of acute fluoride toxicity.Bezerra de Menezes LM, Volpato MC, Rosalen PL, Cury JA.
Faculty of Dentistry, Federal University of Ceara, Rua Alexandre Barauna 949, CEP 60430-160, Fortaleza, CE, Brazil.
The use of bone as a biomarker for chronic and acute exposure to fluoride salts has been suggested, but there are no data published about its use to evaluate lethal intoxication. One hundred and sixty rats were divided into eight groups that received a single oral intubation dose from 0 (control) to 90 mg F/kg as NaF. The animals' time of death was recorded and their femurs were removed for fluoride analysis. Acid-soluble fluoride was determined in the whole bone and on the surface (periosteal), using an ion specific electrode. The data showed a statistically significant relationship between fluoride dose and the number of deaths (P<0.0001). A statistically significant relationship was also found between fluoride dose and fluoride concentration ([F]) in either the whole femur (P<0.0017), on the surface (P<0.0001) or for the ratio periosteal [F]/whole [F] (P<0.0001). However, the [F] on the femur surface was more closely correlated with mortality than that in the whole bone, showing statistically significant differences among the lethal doses and control (P<0.05). The data suggest that the ratio [F] periosteal bone/[F] whole bone, is a biomarker for acute fluoride toxicity.
PMID: 14609659 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14682644&dopt=AbstractJ Public Health Dent. 2003 Fall;63(4):211-20.
Patterns of fluoride intake from 36 to 72 months of age.Levy SM, Warren JJ, Broffitt B.
Department of Preventive and Community Dentistry, N330 DSB, College of Dentistry, University of Iowa, Iowa City, IA 52242, USA. steven-levy@uiowa.edu
OBJECTIVES: This paper reports on estimated daily fluoride intake from water by itself, beverages, selected foods, dentifrice, and dietary supplements, both individually and combined (mg and mg F/kg bw), among 785 children in the Iowa Fluoride Study from 36 to 72 months of age.
METHODS: Children were recruited in 1992-95, with questionnaires sent at four- to six-month intervals. Dietary fluoride intake estimates used community and individual water fluoride levels and average fluoride levels of beverages and foods prepared with water. Descriptive statistics and generalized linear models (GLM) assessed levels and associations with demographic factors.
RESULTS: There was substantial variation in fluoride intake, with some individuals' intakes greatly exceeding the means. Daily water fluoride intake estimates (in mg) increased with age, fluoride intake from other beverages and dentifrice both decreased slightly, and combined intake was quite consistent. For combined intake per unit body weight (mg F/kg bw), there was a steady decline with age. Therefore, the percentages with estimated intake exceeding possible thresholds for dental fluorosis also declined with age.
CONCLUSIONS: Daily mean fluoride intakes from single and combined sources are relatively stable from 36-72 months of age among these children.
PMID: 14682644 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14674546&dopt=AbstractJ Environ Qual. 2003 Nov-Dec;32(6):2230-7.
Biogeochemistry of fluoride in a plant-solution system.
Mackowiak CL, Grossl PR, Bugbee BG.
Plants, Soils, and Biometeorology Dep., Utah State Univ., Logan, UT 84322-4820, USA. cmackow@cc.usu.edu
Fluoride (F-) pollutants can harm plants and the animals feeding on them. However, it is largely unknown how complexing and chelating agents affect F bioavailability. Two studies were conducted that measured F- bioavailability and uptake by rice (Oryza sativa L.). In the first study, rice was grown in solution culture (pH 5.0) with 0, 2, or 4 mM F- as KF to compare the interaction of F- with humic acid (HA) and with a conventional chelating agent, N-hydroxyethylenthylenediaminetriacetic acid (HEDTA). In the second study, F was supplied at 0, 0.5, 1.0, and 2.0 mM KF with an additional 2 mM F- treatment containing solution Ca at 2x (2 mM Ca) the level used in the first study, to test the effect added Ca had on F- availability and uptake. Total biomass was greatest with HEDTA and F- < 1 mM. Leaf and stem F concentrations increased exponentially as solution F- increased linearly, with nearly no F partitioning into the seed. Results suggest that F was taken up as HF0 while F- uptake was likely restricted. Additionally, F- competed with HA for Ca, thus preventing the formation of Ca-HA flocculents. The addition of soluble Ca resulted in the precipitation of CaF2 solids on the root surface, as determined by tissue analysis and energy dispersive X-ray spectroscopy.PMID: 14674546 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14618705&dopt=AbstractBiofouling. 2003 Apr;19 Suppl:59-62.
Elastomeric fluorinated polyurethane coatings for nontoxic fouling control.
Brady RF Jr, Aronson CL.Chemistry Division, Naval Research Laboratory, Washington, DC 20375-5342, USA. SharonandBobB@aol.com
Nontoxic antifouling coatings have been investigated for many years as possible successors to toxic antifouling paints. Polymers containing fluorine or silicone have been tested and each has been shown to be partially effective for different reasons. This paper describes a new coating which combines the best features of fluorinated and silicone coatings and is non-toxic. Four fluorinated elastomers were prepared and tested for fouling resistance during a full fouling season. The surface energy and mechanical properties of each polymer were measured and correlated to fouling performance. One of the elastomers was shown to foul slowly, clean easily, be durable in the marine environment and organisms bonded to it only weakly. The surface energy, elastic modulus, and thickness of the elastomer may be varied as desired over wide ranges to meet differing performance requirements.PMID: 14618705 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14598740&dopt=AbstractGig Sanit. 2003 Sep-Oct;(5):7-11.
[In Process Citation]
[Article in Russian]
[No authors listed]
The paper presents the results of examination of the chemical and radionuclide composition of natural waters and snow cover in Moscow. Areas with abnormal contents of tritium are found in the underground and surface waters and snow cover. The high concentrations of strontium, boron, fluorine, and barium are ascertained to be associated with natural factors. Areas of technogenically polluted underground waters are identified. Recommendations are given for further studies. Particular emphasis is laid on that the artesian wells that are a reservoir source of water supply under emergency are to be revised.PMID: 14598740 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14593393&dopt=AbstractNat Mater. 2003 Nov;2(11):711-2.
No abstract available
Supramolecular chemistry: fluorine makes a difference.Tomalia DA.
Publication Types:
* News
PMID: 14593393 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14672366&dopt=AbstractAnn Chim. 2003 Sep-Oct;93(9-10):753-60.
Removal of fluoride from fluoride contaminated industrial waste water by electrolysis.
Joshi VA, Nanoti MV.
National Environmental Engineering Research Institute, Nagpur--20, India.Wastewater containing fluoride are generally treated with lime or calcium salt supplemented with aluminium salts. Wastewater generated from different industries does not always behave in the same way due to the presence of interfering contaminants. A number of techniques have been developed and studied for the removal of excessive fluoride. Most of these are based on use of aluminium salt. In alum coagulation the sorption properties of product of hydrolysis of aluminium salts and capacity of fluoride for complex formation plays a very important role. These hydrolysis products of aluminium can be produced by passing direct current through aluminium electrode. The text presented in the paper deals with the various aspect of removal of fluoride by electrolysis using aluminium electrode from fluoride chemical based industrial wastewater.
PMID: 14672366 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14661894&dopt=AbstractWaste Manag Res. 2003 Oct;21(5):467-73.
Spent potlining utilisation possibilities.Miksa D, Homsak M, Samec N.
Talum, d.d, Tovarniska 10, 2325 Kidricevo, Slovenia. dragan.miksa@talum.si
As the world's capacity for aluminium production increases, the amount of waste connected with this industry is also increasing. Spent potlining (SPL) from aluminium reduction cell cathodes presents a major environmental concern in the primary aluminium industry. It is concluded, after laboratory tests, that leachable cyanide and fluoride compounds present the major problem in SPL disposal. The behaviour of cyanide and fluoride under high temperature treatment has been investigated. On the basis of this laboratory investigation, the possibilities for SPL utilisation in red brick manufacturing, cement industry and thermal power stations were evaluated. SPL refractory material is already re-used in red brick manufacturing. In the cement industry, a pilot test on the utilisation of 25 t SPL carbon waste mixed with green petrol coke gave positive results. Additionally a fluoride emission forecast for a thermal power station utilising carbon waste SPL mixed with coal was elaborated.
PMID: 14661894 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14633748&dopt=AbstractBr J Anaesth. 2003 Dec;91(6):800-4.
Fluoride metabolism in smokers and non-smokers following enflurane anaesthesia.Laisalmi M, Soikkeli A, Kokki H, Markkanen H, Yli-Hankala A, Rosenberg P, Lindgren L.
Department of Anaesthesia and Intensive Care Medicine, Helsinki University Hospital, Helsinki, Finland. merja.laisalmi@kuh.fi
BACKGROUND: Inorganic fluoride is released by the metabolism of enflurane and the increased serum fluoride concentrations may impair renal function. Tobacco smoke consists of numerous reactive compounds that can either induce or inhibit drug metabolism. Studies on the interaction of smoking with anaesthetic drug metabolism and possible toxicity are warranted.
METHODS: Sixteen non-smoking and 17 smoking (>10 cigarettes day(-1)) generally healthy women undergoing elective gynaecological surgery were given 1 MAC (minimum alveolar concentration)-hour standardized anaesthesia with enflurane in oxygen-air mixture. The serum inorganic fluoride and renal function markers beta(2)-microglobulin, tumour-associated trypsin inhibitor (TATI) and serum creatinine were measured for 48 h.
RESULTS: The greatest inorganic fluoride concentration was between 8.4 and 21.0 (mean 13.8 (SD 3.4)) micromol litre(-1) in the non-smokers and between 8.6 and 38.0 (18.7 (7.0)) micromol litre(-1) in the smokers; the mean difference was 4.9 micromol litre(-1) (95% confidence interval (CI) 1.0-8.8, P<0.05). Serum beta(2)-microglobulin, TATI and creatinine were not increased. Serum inorganic fluoride concentrations were significantly greater in the smokers compared with the non- smokers 1, 2, 3 and 6 h after 1 MAC-hour inhalation with enflurane (P<0.05). Inorganic fluoride concentrations were still increased 24 h after anaesthesia in both groups. Urine beta(2)-microglobulin and TATI creatinine ratio remained at low values during the whole 48-h period in both groups.
CONCLUSIONS: Regular smoking is associated with an increase in serum inorganic fluoride concentration after anaesthesia with enflurane, but there are no signs of renal damage.Publication Types:
* Clinical Trial
PMID: 14633748 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14611260&dopt=AbstractJ Am Chem Soc. 2003 Nov 19;125(46):14210.
No abstract available
Quantitative measure for the "Nakedness" of fluoride ion sources [j. Am. Chem. Soc. 2003, 125, 9457-9461].
Christe KO, Brooke Jenkins HD.
PMID: 14611260 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14561005&dopt=AbstractDig Dis Sci. 2003 Sep;48(9):1804-8.
Fatal cholestatic liver failure associated with gemcitabine therapy.
Robinson K, Lambiase L, Li J, Monteiro C, Schiff M.
Department of Medicine, University of Florida Health Sciences Center, Jacksonville, Florida 32209, USA.
Drug-induced hepatotoxicity accounts for more than a third of the cases of acute liver failure in the United States. In complex medical conditions, the diagnosis of drug-induced liver injury may be confounding and, specifically, the potential hepatotoxicity of chemotherapeutic agents may be easily overlooked. Two fatal cases of cholestatic hepatotoxicity have been previously reported, clearly implicating gemcitabine therapy. We report a third fatal case of cholestatic liver failure that we think is strongly linked to the use of gemcitabine. This chemotherapeutic agent is a fluorine analog with broad-spectrum antitumor activity commonly used in the treatment of breast, lung, prostate, and cervical cancer. The case we report is of a 45-year-old woman with a history of metastatic breast cancer to her spine. The patient was in remission for two years before she presented with a compensated mixed hepatitis of mild to moderate severity. Inpatient work-up found metastases to the right humerus and inferior pubic ramus, but none in the liver. Gemcitabine and carboplatin therapy was initiated for relapse of breast cancer. The patient's liver enzyme elevation diminished, but did not normalize before the start of chemotherapy. She received four courses of gemcitabine/carboplatin and subsequently presented with decompensated, severe cholestatic hepatitis. Transjugular liver biopsy displayed marked cholestasis and hepatocellular injury consistent with drug-induced hepatoxicity. Gemcitabine has been extensively studied in the oncology literature and at this time is thought to be a low-risk hepatotoxin causing hepatic adaptation and transient, reversible liver enzyme elevation, rarely leading to termination of gemcitabine therapy for solid tumors. We believe that gemcitabine therapy, particularly in the setting of preexisting liver injury or metastases to the liver, increases the relative risk of severe and potentially fatal hepatic injury possibly by idiosyncratic and dose-dependent mechanisms. We recommend careful monitoring and dose adjustment of gemcitabine in patients with abnormal liver function tests or evidence of hepatic metastases until further study clarifies this issue.
PMID: 14561005 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14551972&dopt=AbstractHuan Jing Ke Xue. 2003 Jul;24(4):127-30.
[Distribution of fluoride in the combustion products of coal]
[Article in Chinese]
Liu J, Qi Q, Zhou J, Cao X, Cen K.
Clean Energy and Environment Engineering, Key Laboratory of Ministry of Education, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China. jzliu@cmee.zju.edu.cn
The static distribution characteristic of fluoride in the combustion products of coal was studied by ashing procedure of coal, and the dynamic distribution characteristics of fluorine in the combustion products of coal in pulverized-coal-fired boiler and layer-burning boiler were investigated. Experimental results identified that fluorine in coal belong to volatile elements, fluorine in fly ash and bottom ash were non-rich. About 94.5% of the fluorine in coal emitted as gaseous-fluorine during coal combustion in pulverized-coal-fired boiler, and about 80% of the fluorine in coal emitted as gaseous-fluorine during coal combustion in layer-burning boiler. 55%-60% of the fluorine in fly ash of pulverized-coal-fired boiler were distributed in fly ash particles with a diameter of 74 microns-104 microns.
PMID: 14551972 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14593393&dopt=AbstractNat Mater. 2003 Nov;2(11):711-2.
No Abstract available
Supramolecular chemistry: fluorine makes a difference.
Tomalia DA.
Publication Types: News
PMID: 14593393 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14609659&dopt=AbstractForensic Sci Int. 2003 Nov 26;137(2-3):209-14.
Bone as a biomarker of acute fluoride toxicity.
Bezerra de Menezes LM, Volpato MC, Rosalen PL, Cury JA.
Faculty of Dentistry, Federal University of Ceara, Rua Alexandre Barauna 949, CEP 60430-160, CE, Fortaleza, Brazil
The use of bone as a biomarker for chronic and acute exposure to fluoride salts has been suggested, but there are no data published about its use to evaluate lethal intoxication. One hundred and sixty rats were divided into eight groups that received a single oral intubation dose from 0 (control) to 90mgF/kg as NaF. The animals' time of death was recorded and their femurs were removed for fluoride analysis. Acid-soluble fluoride was determined in the whole bone and on the surface (periosteal), using an ion specific electrode. The data showed a statistically significant relationship between fluoride dose and the number of deaths (P<0.0001). A statistically significant relationship was also found between fluoride dose and fluoride concentration ([F]) in either the whole femur (P<0.0017), on the surface (P<0.0001) or for the ratio periosteal [F]/whole [F] (P<0.0001). However, the [F] on the femur surface was more closely correlated with mortality than that in the whole bone, showing statistically significant differences among the lethal doses and control (P<0.05). The data suggest that the ratio [F] periosteal bone/[F] whole bone, is a biomarker for acute fluoride toxicity.
PMID: 14609659 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14562997&dopt=AbstractCalcif Tissue Int. 2003 Jun;72(6):689-93.
Bone mineral density of the spine and femur in early postmenopausal Turkish women with endemic skeletal fluorosis.
Yildiz M, Akdogan M, Tamer N, Oral B.
Department of Nuclear Medicine, Suleyman Demirel University, School of Medicine, Isparta, Turkey. mustiyildiz01@ixir.com
The aim of this prospective, comparative study was to investigate the bone mineral density (BMD) changes in a group of early postmenopausal Turkish women with endemic skeletal fluorosis and to study effects of endemic fluorosis on BMD. Bone mineral density of L2-L4 vertebra, femur neck, femur trochanter, and Ward's triangle were measured in 45 female patients with endemic skeletal fluorosis and 41 age-matched controls by dual X-ray absorbtiometry (DXA). The BMD of L2-L4 vertebra and Ward's triangle were higher in the endemic fluorosis group than in the control group (P < 0.001). Patients with endemic fluorosis had higher femur neck and femur trochanter BMDs than did controls (P < 0.01 and P < 0.05, respectively). There was a positive correlation between serum fluoride content and BMD at the spine (r = 0.345, P = 0.001), femoral neck (r = 0.274, P = 0.011), Ward's triangle (r = 0.295, P = 0.006), and trochanter (r = 0.217, P = 0.045). In conclusion, higher bone mineral density levels were seen in early postmenopausal women with endemic skeletal fluorosis. BMD measurement is a tool in the diagnosis and management of this preventable crippling disease.
PMID: 14562997 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14600463&dopt=AbstractOtol Neurotol. 2003 Nov;24(6):854-62.
Increased activity of the diastrophic dysplasia sulfate transporter in otosclerosis and its inhibition by sodium fluoride.
Grayeli AB, Escoubet B, Bichara M, Julien N, Silve C, Friedlander G, Sterkers O, Ferrary E.
INSERM Unite 426, Faculte Xavier Bichat, Universite Paris 7, Paris, France. alexis.bozorg-grayeli@bjn.ap-hop-paris.fr
HYPOTHESIS: This study investigates the function of the diastrophic dysplasia sulfate transporter (DTDST) in otosclerotic bone and the effect on it of sodium fluoride (NaF).
BACKGROUND: Otosclerosis is a localized bone dystrophy with increased bone turnover. DTDST is implicated in the regulation of the bone turnover.
MATERIALS AND METHODS: Primary cultures of cells were obtained from the stapes and external auditory canal (EAC) of 26 patients with otosclerosis and from nine control patients. Sulfate uptake was quantified under basal conditions and with NaF. The NaF signaling pathways were investigated using forskolin and verapamil.
RESULTS: The relative initial rates of sulfate uptake and the apparent Vmax values were: otosclerotic stapes > EAC > control stapes = control EAC. The sulfate uptake by the otosclerotic stapes was correlated with the loss of sensorineural hearing. The amounts of DTDST mRNA (RNase protection assay) in the four subgroups did not differ. NaF (10(-6)M, 1 hr) inhibited sulfate uptake by the otosclerotic stapes and EAC cells but not by control samples.
CONCLUSION: The authors believe that whether the increased DTDST activity is a cause or an effect of otosclerosis, it appears to be a specific target for NaF treatment.PMID: 14600463 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14502584&dopt=AbstractEnviron Toxicol. 2003 Oct;18(5):317-20.
Fluoride contamination of aquifers in the southeast subhumid pampa, Argentina.
Paoloni JD, Fiorentino CE, Sequeira ME.
Departamento de Agronomia (UNS) (CONICET), San Andres 850-(8000) Bahia Blanca, Rca. Argentina.
A diagnostic survey was carried out of the groundwater in the southeast subhumid pampa of Argentina in order to determine the presence, spatial distribution, and concentration of fluoride. The area studied extends along the southeastern border of the pampa plains between latitude 38 degrees 18' and 38 degrees 58' S and longitude 60 degrees 43' and 61 degrees 43' W, covering an irregular surface area of approximately 6000 km(2). The region has a large rural and suburban population that relies on this groundwater as its principal source of water for human consumption and for use in agricultural and livestock production. The variation in fluoride content in the groundwater is illustrated on maps of the area, showing that the whole region is affected by this ion contaminant. In 97.1% of the samples fluoride values exceeded the limits recommended by the Argentine Food Code for human consumption and indicated that the use of the water in livestock should be restricted. The quality of the water for irrigation purposes also was seriously affected. Critically affected zones were identified with a view to implementing public health measures to protect against this highly contaminated resource. Copyright 2003 Wiley Periodicals, Inc. Environ Toxicol 18: 317-320, 2003.
PMID: 14502584 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14499534&dopt=AbstractSci Total Environ. 2003 Oct 1;314-316:209-31.
Fluoride in UK rivers.
Neal C, Neal M, Davies H, Smith J.
Centre for Ecology and Hydrology, Crowmarsh Gifford, Oxon., OX10 8BB, Wallingford, UK
Fluoride concentrations in eastern UK rivers (the Humber, Tweed, Wear, Great Ouse and Thames) are described based on information collected within the Land-Ocean Interaction Study (LOIS) and by the Environment Agency (EA) of England and Wales. The results show varied fluoride concentrations across the region, with a range from <0.01 to >10 mg l(-1); and mean, median and range in mean concentrations of 0.30, 0.21 and 0.05-3.38 mg l(-1) (excluding one outlier point), respectively. Within the main rivers and tributaries, the mean fluoride concentration varied from approximately 0.5 to over 2 mg l(-1) and the highest values occurred within the Don basin (Don, Dearne and Rother) and parts of the Trent basin (upper Tame and mid-upper Derbyshire Derwent) in highly industrialised and urbanised areas (Sheffield and Rotherham in the Don basin; Birmingham and Derby on the Trent). For localised inputs to the rivers, fluoride concentrations were slightly higher, and considerably higher in one outlier case. Correspondingly, the other rivers examined typically had mean fluoride concentrations between approximately 0.2 and 0.5 mg l(-1), but fluoride concentrations were lower in the headwater areas. As there is much less information on fluoride levels in upland areas, extensive data collected as part of an acid waters survey are used to show that fluoride concentrations are generally less than 0.1 mg l(-1) for the upland UK. The data are summarised in terms of both fluoride concentrations and flux, and the values are cross-referenced to other determinands collected within LOIS. The high positive correlation with boron and negative correlation with flow show the importance of point source (sewage) inputs of fluoride, while strong positive correlations between fluoride and barium indicate the relative importance of vein mineralisation in the bedrock in supplying fluoride to the waters of the Yorkshire Ouse and its tributaries. There seems to be some process that limits the fluoride concentrations within the more contaminated rivers, and this is indicated by a negative upper bound between fluoride and calcium. The waters are undersaturated with respect to fluorite and oversaturated with respect to calcium fluoro-phosphates. This upper bound may reflect either physical controls, such as the availability and size of point and diffuse sources for fluoride coupled to mixing of these sources with rain and soil runoff of low concentration, or solubility controls for a pure or mixed-phase mineral that cannot be specified here.
PMID: 14499534 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12971250&dopt=AbstractEnviron Geochem Health. 2003 Sep;25(3):281-95.
Developing environmental health indicators as policy tools for endemic fluorosis management in the People's Republic of China.
Yang L, Peterson PJ, Williams WP, Wang W, Li R, Tan J.
Institute of Geographical Sciences and Natural Resources, Chinese Academy of Science, Beijing 100101, PR China.
Drinking groundwater containing naturally occurring elevated concentrations of fluoride has given rise to extensive dental and skeletal fluorosis affecting many millions of people in China. This paper describes three sets of indicators useful for environmental and human fluorosis management purposes, namely, descriptive indicators (the past), response indicators (the present) and performance indicators (the future). Each of the sets of indicators was further detailed following the Organisation for Economic Co-operation and Development (OECD) pressure-state-response model modified to include an impact parameter. But as managers need more aggregated information to summarise monitoring data, two indices were constructed from identified indicators, namely, a four component (indicators) 'health impact index', and a three component (indicators) 'management capability index'. Data from 14 provinces and autonomous regions were used to illustrate the application of the two indices. Results showed major differences in the values for the indices for management actions and human health outcomes at the provincial level. Provinces with a low management capability index, for example, Inner Mongolia, had a high health impact index, while provinces with a high management capability index, for example, Shandong had a low health impact index. It was concluded that a greater emphasis should be given in China, not just to monitoring fluorosis occurrence, but to the development of indicators and indices that empower decision-makers to initiate strategies to more effectively manage this major endemic disease.
PMID: 12971250 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12929153&dopt=AbstractAm J Ind Med. 2003 Sep;44(3):321-4.
Asthma following household exposure to hydrofluoric acid.
Franzblau A, Sahakian N.
Associate Professor of Occupational Medicine, Department of Environmental Health Sciences, University of Michigan School of Public Health, Washington Heights, Ann Arbor, Michigan.
BACKGROUND: Almost all reports of respiratory health effects of hydrofluoric acid are derived from industrial settings and usually involved massive and conspicuous exposures. In the present report we describe a case of adult-onset asthma immediately following use of a household rust stain remover that contained an 8-9% aqueous solution of hydrofluoric acid (HF).
METHODS: This is a case-report. A literature search of hydrogen fluoride, and reactive airways dysfunction syndrome (RADS) was performed.
RESULTS: A previously healthy 26-year-old woman developed asthma immediately following inhalation exposure to hydrofluoric acid from a household cleaner, consistent with reactive airways dysfunction syndrome. The circumstances of exposure and possible mechanism of disease are discussed.
CONCLUSIONS: It is likely that this patient's use of the rust stain remover resulted in inhalation exposure to hydrofluoric acid well above any applicable standard, and hence constituted a 'high level' irritant exposure capable of inducing reactive airways dysfunction syndrome. In our opinion, the presence of this concentration hydrofluoric acid in a consumer product may be unduly hazardous. Copyright 2003 Wiley-Liss, IncPMID: 12929153 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12927553&dopt=AbstractEcotoxicol Environ Saf. 2003 Oct;56(2):222-7.
Prevention and control of brick-tea type fluorosis-a 3-year observation in Dangxiong, Tibet.
Jin C, Yan Z, Jian-Wei L, Ruoden X, Sangbu D, Zeguo, Zhouma S.
Tea and Health Laboratory, Xiangya School of Medicine, Central-South University, Tibet, China
To evaluate the effects of preventing and controlling brick-tea type fluorosis, we carried out a 3-year field observation and assayed the total daily fluoride intake, urinary and serum fluoride level, and dental fluorosis prevalence and index in a boarding school in Dangxiong, Tibet, in students aged 8-15. We replaced the traditional brick tea with low-fluoride brick tea (LFBT). Reduction in the traditional brick-tea consumption decreased the total daily fluoride intake among the children, which still remained within the level of chronic intoxication but at a safe level. The study suggests that the LFBT is effective in the prevention and control of endemics of brick tea type fluorosis, although further improvement of the LFBT is required.
PMID: 12927553 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12963308&dopt=AbstractEnviron Pollut. 2003;126(3):445-57.
Sulfate, chloride and fluoride retention in Andosols exposed to volcanic acid emissions.
Delmelle P, Delfosse T, Delvaux B.
Unite des sciences du sol, Croix du sud 2/10, Universite catholique de Louvain, B-1348, Louvain-la-Neuve, Belgium
The continuous emissions of SO(2), HCl and HF by Masaya volcano, Nicaragua, represent a substantial source of atmospheric S-, Cl- and F-containing acid inputs for local ecosystems. We report on the effects of such acid depositions on the sulfate, chloride and fluoride contents in soils (0-40 cm) from two distinct transects located downwind from the volcano. The first transect corresponds to relatively undifferentiated Vitric Andosols, and the second transect to more weathered Eutric Andosols. These soils are exposed to various rates of volcanogenic acid addition, with the Vitric sites being generally more affected. Prolonged acid inputs have led to a general pH decrease and reduced exchangeable base cation concentrations in the Andosols. The concentrations of 0.5 M NH(4)F- and 0.016 M KH(2)PO(4)-extractable sulfate (NH(4)F-S and KH(2)PO(4)-S, respectively) indicate that volcanic S addition has increased the inorganic sulfate content of the Vitric and Eutric soils at all depths. In this process, the rate of sulfate accumulation is also dependent on soil allophane contents. For all soils, NH(4)F extracted systematically more (up to 40 times) sulfate than KH(2)PO(4). This difference suggests sulfate incorporation into an aluminum hydroxy sulfate phase, whose contribution to total inorganic sulfate in the Vitric and Eutric Andosols is estimated from approximately 34 to 95% and approximately 65 to 98%, respectively. The distribution of KH(2)PO(4)-extractable chloride in the Vitric and Eutric Andosols exposed to volcanic Cl inputs reveals that added chloride readily migrates through the soil profiles. In contrast, reaction of fluoride with Al and Fe oxyhydroxides and allophanes is an important sink mechanism in the Masaya Andosols exposed to airborne volcanic F. Fluoride dominates the anion distribution in all soil horizons, although F is the least concentrated element in the volcanic emissions and depositions. The soil anion distribution reflects preferential retention of fluoride over sulfate and chloride, and of sulfate over chloride. The primary acidifying agent of the Andosols subject to the volcanic acid inputs is HCl.
PMID: 12963308 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12909089&dopt=AbstractWaste Manag. 2003;23(6):483-91.
Study of the presence of fluorine in the recycled fractions during carbothermal treatment of EAF dust.
Menad N, Ayala JN, Garcia-Carcedo F, Ruiz-Ayucar E, Hernandez A.
Centro Nacional de Investigaciones Metalurgicas Avda. Gregorio del Amo, 8-28040, Madrid, Spain
Carbothermal treatment tests of electric arc furnace dusts (EAFD) using the Waelz kiln process were carried out in pilot-scale for the production of zinc oxide. The association of halides in the EAFD, and the recycled products, such as zinc oxide fumes and high-grade iron contents fractions were examined by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis. XRD reveals the presence of chlorine and fluorine in the dusts in the form of KCl, NaCl and CaF(2). An ultra-pure fraction of zinc was obtained after the Double Leaching Waelz Oxide (DLWO) process was performed on the zinc oxide fumes. The halide contents were reduced to approximately 100 ppm Cl and 700 ppm F. The rest of these elements are in the form of CaF(2). About 65% F is volatilised as lead and zinc fluorides, 15% is expected in the magnetic fractions and 20% in non-magnetic fractions as CaF(2) and MnF(2), respectively.
PMID: 12909089 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12887803&dopt=AbstractZhonghua Kou Qiang Yi Xue Za Zhi. 2003 May;38(3):217-9.
[The effect of overdose fluoride on the proliferation and apoptosis of rat's incisor ameloblast]
[Article in Chinese]
Sun HC, Liu M, Ouyang J, Li GS.
Department of Oral Pathology, School of Stomatology, Jilin University, Changchun 130041, China.
OBJECTIVE: To observe the effect of overdose fluoride on the proliferation of rat's incisor ameloblast.
METHODS: 20 Wistar rats were divided randomly into 2 groups: Group I (Control); Group II 50 mg/L F(-) were given. After 8 weeks treatment, the AgNORs stain and TUNEL technique were applied to analyze the effect of fluoride on the proliferation and apoptosis of ameloblasts.
RESULTS: The imagination analysis results showed that proliferation of pre-secretion ameloblasts were inhibited in group II as compared with the control group (P < 0.001). There was significant increase of apoptosis with the trend of migration toward secretion stage.
CONCLUSION: The mechanism of fluorosis mottled enamel may be the effect of overdose fluoride with inhibits proliferation and induces apoptosis of ameloblasts resulting in dysfunction of secretion or absorption of enamel matrix proteins.PMID: 12887803 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12871734&dopt=AbstractChemosphere. 2003 Sep;52(10):1677-81.
Temporal variation of fluoride concentration in antlers of roe deer (Capreolus capreolus) living in an area exposed to emissions from iron and steel industry, 1948-2000.
Kierdorf U, Kierdorf H.
Institute of General and Systematic Zoology, Justus-Liebig-University of Giessen, Heinrich-Buff-Ring 26-32, D-35392, Giessen, Germany
Temporal changes of environmental fluoride concentration in the industrialized area of Siegen, western Germany were assessed by studying the fluoride content of antlers (n=116) collected between 1948 and 2000 from the resident roe deer (Capreolus capreolus) population. During the analyzed period, major fluoride emission sources in the study area have been iron- and steelworks. Fluoride concentrations in the antlers ranged between 118 and 5428 mg/kg of bone ash. There was an overall increase in antler fluoride content from the late 1940s/early 1950s to the late 1950s/mid-1960s. Thereafter, antler fluoride levels overall steadily declined. For statistical analysis, the data were grouped into five periods (1948-1959, 1960-1969, 1970-1979, 1980-1989, and 1990-2000). Geometric mean fluoride concentrations of the samples ranged from 323 (period 1990-2000) to 2096 mg/kg of bone ash (period 1960-1969). Sample means for the periods 1980-1989 and 1990-2000, respectively, were always significantly lower than those of older samples. The decrease in antler fluoride concentrations during recent decades suggests a drop of ambient fluoride levels, that is hypothetically attributed to a reduction in the number of emission sources in the area and a decline of fluoride discharges from both local and more distant sources due to improved emission control measures. Comparison with antler fluoride data for other roe deer populations from western Germany further suggests that the roe deer from the Siegen area were recently exposed to an only moderate additional fluoride load from industrial sources. Studying antler fluoride concentrations is a convenient and cost-effective method of monitoring temporal changes in ambient fluoride levels.
PMID: 12871734 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12867178&dopt=AbstractChemosphere. 2003 Sep;52(9):1475-82.
Fluoride and aluminium concentrations of tea plants and tea products from Sichuan Province, PR China.
Shu WS, Zhang ZQ, Lan CY, Wong MH.
State Key Laboratory for Bio-control, School of Life Sciences, Zhongshan University, 510275, Guangzhou, People's Republic of China
Some Tibetans in Sichuan Province in southwestern China have been suffering from fluorosis, due to drinking and eating tea with high fluoride (F) and aluminium (Al) contents. Tea plants, soils of tea plantations and tea products from Yaan, Gaoxian and Yibin Cities in Sichuan Province were investigated to evaluate the factors affecting F and Al contents in tea products. The F and Al concentrations of four commercial brands of brick teas were significantly higher than those of 11 brands of green teas. Chemical analysis indicated that total and available F and Al concentrations in tea plantation soils in Yaan and Gaoxian were within the normal range compared with acid soils in South China and tea soils in Fujian Province. Edaphic conditions did not contribute to the high F and Al concentrations in brick tea. Analysis of raw materials of brick tea indicated that old leaves were the major contributors to the high F and Al contents contained in brick tea. There were also great variations among different tea varieties in accumulating F and Al, and concentrations of F and Al in tea variety of Qianmei 303 were about 2-3-fold higher than the other three varieties. Selection of appropriate varieties would be important to lower F and Al contents in tea products.
PMID: 12867178 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12738253&dopt=Abstract
Chemosphere. 2003 Jul;52(2):289-97.
The diversity of naturally produced organohalogens.
Gribble GW.
Department of Chemistry, Dartmouth College, 6128 Burke Laboratory, 03755-3564, Hanover, NH, USA
More than 3800 organohalogen compounds, mainly containing chlorine or bromine but a few with iodine and fluorine, are produced by living organisms or are formed during natural abiogenic processes, such as volcanoes, forest fires, and other geothermal processes. The oceans are the single largest source of biogenic organohalogens, which are biosynthesized by myriad seaweeds, sponges, corals, tunicates, bacteria, and other marine life. Terrestrial plants, fungi, lichen, bacteria, insects, some higher animals, and even humans also account for a diverse collection of organohalogens.
PMID: 12738253 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12850886&dopt=AbstractInt J Food Sci Nutr. 2003 Jul;54(4):247-59.
The fruit of the date palm: its possible use as the best food for the future?
Al-Shahib W, Marshall RJ.
The fruits (dates) of the date palm (Phoenix dactylifera L.) contain a high percentage of carbohydrate (total sugars, 44-88%), fat (0.2-0.5%), 15 salts and minerals, protein (2.3-5.6%), vitamins and a high percentage of dietary fibre (6.4-11.5%). The flesh of dates contains 0.2-0.5% oil, whereas the seed contains 7.7-9.7% oil. The weight of the seed is 5.6-14.2% of the date. The fatty acids occur in both flesh and seed as a range of saturated and unsaturated acids, the seeds containing 14 types of fatty acids, but only eight of these fatty acids occur in very low concentration in the flesh. Unsaturated fatty acids include palmitoleic, oleic, linoleic and linolenic acids. The oleic acid content of the seeds varies from 41.1 to 58.8%, which suggests that the seeds of date could be used as a source of oleic acid. There are at least 15 minerals in dates. The percentage of each mineral in dried dates varies from 0.1 to 916 mg/100 g date depending on the type of mineral. In many varieties, potassium can be found at a concentration as high as 0.9% in the flesh while it is as high as 0.5% in some seeds. Other minerals and salts that are found in various proportions include boron, calcium, cobalt, copper, fluorine, iron, magnesium, manganese, potassium, phosphorous, sodium and zinc. Additionally, the seeds contain aluminum, cadmium, chloride, lead and sulphur in various proportions. Dates contain elemental fluorine that is useful in protecting teeth against decay. Selenium, another element believed to help prevent cancer and important in immune function, is also found in dates. The protein in dates contains 23 types of amino acids, some of which are not present in the most popular fruits such as oranges, apples and bananas. Dates contain at least six vitamins including a small amount of vitamin C, and vitamins B(1) thiamine, B(2) riboflavin, nicotinic acid (niacin) and vitamin A. The dietary fibre of 14 varieties of dates has been shown to be as high as 6.4-11.5% depending on variety and degree of ripeness. Dates contain 0.5-3.9% pectin, which may have important health benefits. The world production of dates has increased 2.9 times over 40 years, whereas the world population has doubled. The total world export of dates increased by 1.71% over 40 years. In many ways, dates may be considered as an almost ideal food, providing a wide range of essential nutrients and potential health benefits.
PMID: 12850886 [PubMed - in process]
Full free text in Spanish available at http://db.doyma.es/cgi-bin/wdbcgi.exe/doyma/mrevista.pubmed_full?inctrl=05ZI0106&rev=28&vol=21&num=5&pag=261PubMed abstract at http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12732116&dopt=Abstract
Enferm Infecc Microbiol Clin. 2003 May;21(5):261-8.
[Quinolones]
[Article in Spanish]
Alos JI.
Servicio de Microbiologia. Hospital de Mostoles. Madrid. Espana.
Quinolones act by inhibiting enzymes (topoisomerases), which are indispensable to DNA synthesis. Their bactericidal activity is concentration-dependent. Their spectrum has become broader, especially since the introduction of a fluorine atom at position 6 (fluoroquinolones).They are used as the treatment of choice or as alternative therapy in a wide variety of infections, both in the hospital and non-hospital setting. Depending on the compound, they are used in urinary tract infections, sexually transmitted diseases, chronic osteomyelitis, respiratory tract infections, and severe systemic infections, among others.The upsurge and extent of quinolone resistance has limited the use of these agents in some cases and in future may determine their use in others. There are strategies to minimize the spread of resistance.Quinolones are safe and well tolerated. The most frequent adverse effects are gastrointestinal and those affecting the central nervous system.
PMID: 12732116 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12830900&dopt=AbstractJ Chromatogr A. 2003 May 16;997(1-2):259-67.
Monitoring trace anion contamination in disk drive components.
Kaiser E, Rohrer J, Campbell F.
Dionex Corporation, PO Box 3603, 1228 Titan Way, Sunnyvale, CA 94088-3603, USA. edward.kaiser@dionex.com
Ion chromatography was used to determine trace anionic contamination on the surface of hard disk drive components. These contaminants can have a detrimental effect on device reliability and yield. Disk drive components were soaked in deionized water and these extracts were analyzed for anions. The anions fluoride, acetate, formate, acrylate, methacrylate, chloride, nitrite, bromide, nitrate, benzoate, sulfate, oxalate, phthalate and phosphate were separated on a high-performance anion-exchange column and determined at concentrations less than 1 microg/l with suppressed conductivity detection. The extract solutions were analyzed either by injecting 1 ml or by preconcentrating 5 ml. We evaluated the performance of both methods.
PMID: 12830900 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12828267&dopt=AbstractCommunity Dent Health. 2003 Jun;20(2):83-8.
The use of school milk as a vehicle for fluoride in Knowsley, UK; an evaluation of effectiveness.
Ketley CE, West JL, Lennon MA.
Department of Clinical Dental Sciences, The University of Liverpool, Liverpool, UK.
OBJECTIVE: To compare caries in children initially aged 3 to 5 years who had participated for four years in a fluoridated school milk programme with a group of children in a similar community drinking non-fluoridated milk.
STUDY DESIGN: A four-year longitudinal study measuring caries experience and caries increment in primary molars and caries experience in permanent molars and incisors.
METHOD: 478 children in Knowsley (test group) and 396 in Skelmersdale (comparison group) were examined for caries (dmft/dfs) at baseline in 1997. Of these, 318 in Knowsley and 233 in Skelmersdale were re-examined at follow-up (dmft/dfs and DMFT/DFS) in 2001.
RESULTS: The mean ages at baseline of the children from the test and comparison groups were 4.7 and 4.8 years respectively. The baseline dmft/dfs was 1.73/2.51 in the test group and 1.29/2.15 in the comparison group. The 4-year dmft/dfs mean increments were 2.28/4.49 and 1.96/4.12 in test and comparison groups respectively. The DMFT/DFS at age 7-9 years in the test and comparison groups were 0.40/0.45 and 0.40/0.55 respectively.
CONCLUSION: The fluoridated school milk scheme, as configured in Knowsley. Merseyside, did not reduce caries within the primary dentition and, at best, had a small clinical impact on the permanent dentition up to 8 years of age.
PMID: 12828267 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12837112&dopt=AbstractJ Am Chem Soc. 2003 Jul 9;125(27):8390-9.
Computational study of the halogen atom-benzene complexes.
Tsao ML, Hadad CM, Platz MS.
Contribution from the Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210.
The structures of halogen atom-benzene complexes were investigated by modern DFT and ab initio computational methods. The spectroscopic properties of the complexes are also predicted and are in good agreement with experiment where such data have been reported. The fluorine atom-benzene complex is predicted to be a sigma complex due to the strength of a C-F bond. The chlorine atom-benzene complex is predicted to have an eta(1) pi complex structure, which is only slightly more favorable (1.1 kcal/mol with the BH&HLYP/6-311++G method including the ZPE correction) than a sigma complex but is significantly more stable (4.4 kcal/mol with the BH&HLYP/6-311++G method including the ZPE correction) than the eta(6) pi complex. The bromine and iodine benzene complexes are also predicted to prefer an eta(1) pi complex structure.
PMID: 12837112 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12783820&dopt=AbstractAnn N Y Acad Sci. 2003 Mar;984:226-44.
High performance perfluoropolymer films and membranes.
Arcella V, Ghielmi A, Tommasi G.
Solvay Solexis, Bollate (MI), Italy.
Membrane processes are receiving increasing attention in the scientific community and in industry because in many cases they offer a favorable alternative to processes that are not easy to achieve by conventional routes. In this context, membranes made with perfluorinated polymers are of particular interest because of the unique features demonstrated by these materials. Both highly hydrophobic and hydrophilic membranes have been developed from appropriate perfluoropolymers that were, in turn, obtained by copolymerizing TFE with special monomers available on an industrial scale. Highly hydrophobic membranes obtained from the glassy copolymers of TFE and 2,2,4-trifluoro-5 trifluoromethoxy-1,3 dioxole (Hyflon AD) exhibit properties that make them particularly well suited for use in optical applications, in the field of gas separation, and in gas-liquid contactors. Conditions for preparing membranes that are adequate for use in various applications are exemplified. Hydrophylic highly conductive proton exchange membranes obtained from the copolymer of TFE and a short-side-chain (SSC) perfluorosulfonylfluoridevinylether (Hyflon Ion) find interesting application in the field of fuel cells, especially in view of the current tendency to move to high temperature operation. The advantages offered by these hydrophobic and hydrophylic perfluorinated materials for use in membrane technology are discussed. Comparison of membrane properties and performance is made with other membranes available on the market.
Publication Types: Review; Review, Tutorial
PMID: 12783820 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12826384&dopt=AbstractSci Total Environ. 2003 Jul 20;311(1-3):65-80.
Drinking water quality in the Ethiopian section of the East African Rift Valley I-data and health aspects.
Reimann C, Bjorvatn K, Frengstad B, Melaku Z, Tekle-Haimanot R, Siewers U.
Geological Survey of Norway, N-7491, Trondheim, Norway
Drinking water samples were collected throughout the Ethiopian part of the Rift Valley, separated into water drawn from deep wells (deeper than 60 m), shallow wells (<60 m deep), hot springs (T>36 degrees C), springs (T<32 degrees C) and rivers. A total of 138 samples were analysed for 70 parameters (Ag, Al, As, B, Ba, Be, Bi, Br, Ca, Cd, Ce, Cl, Co, Cr, Cs, Cu, Dy, Er, Eu, F, Fe, Ga, Gd, Ge, Hf, Hg, Ho, I, In, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, NO(2), NO(3), Pb, Pr, Rb, Sb, Se, Si, Sm, Sn, SO(4), Sr, Ta, Tb, Te, Th, Ti, Tl, Tm, U, V, W, Y, Yb, Zn, Zr, temperature, pH, conductivity and alkalinity) with ion chromatography (anions), spectrometry (ICP-OES and ICP-MS, cations) and parameter-specific (e.g. titration) techniques. In terms of European water directives and WHO guidelines, 86% of all wells yield water that fails to pass the quality standards set for drinking water. The most problematic element is fluoride (F), for which 33% of all samples returned values above 1.5 mg/l and up to 11.6 mg/l. The incidence of dental and skeletal fluorosis is well documented in the Rift Valley. Another problematic element may be uranium (U)-47% of all wells yield water with concentrations above the newly suggested WHO maximum acceptable concentration (MAC) of 2 &mgr;g/l. Fortunately, only 7% of the collected samples are above the 10 &mgr;g/l EU-MAC for As in drinking water.
PMID: 12826384 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12818550&dopt=AbstractBiomaterials. 2003 Sep;24(21):3777-3785.
Influence of fluorine in the synthesis of apatites. Synthesis of solid solutions of hydroxy-fluorapatite.
Rodri;guez-Lorenzo LM, Hart JN, Gross KA.
School of Physics and Materials Engineering, Monash University, P.O. Box 69 M, Vic. 3800, Australia
Hydroxy-fluorapatites (OH-FAps) occur biologically in teeth and form the basis for application as biomaterials. This work aims to synthesize a series of fluoride substituted calcium hydroxyapatites (OHAps) to determine how fluoride influences the synthesis and the resulting characteristics of solid solutions. OH-FAPs powders were synthesized with a chemical composition of Ca(10)(PO(4))(6)(OH)(2-x) F(x), with x=0.0, 0.4, 0.8, 1.2, 1.6 and 2.0. The synthesis of partially substituted OHAp yields materials with lower crystallinity and higher specific surface area than OHAp or fluorapatite (FAp). The smallest crystal size of 263A, occurs at less than 50% hydroxyl substitution with fluoride at x=0.4, and the highest surface area of 132m(2)/g occurs at x=0.8. Reaction kinetics occur faster at higher fluoride content, producing the expected Ca/P ratio of 1.67 only for x=2.0. X-ray and IR studies show that OH-FAPs are homogeneous solid solutions instead of mixtures of OHAp and FAp. The presence of a high fluoride concentration increases the driving force for crystal growth during the calcination process.
PMID: 12818550 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12804822&dopt=AbstractEnviron Pollut. 2003;125(1):3-11.
Native plant species suitable as bioindicators and biomonitors for airborne fluoride.
Weinstein LH, Davison AW.
Boyce Thompson Institute, Tower Road, 14850, Ithaca, NY, USA
The strengths and limitations of techniques for biomonitoring and bioindicating fluorides are reviewed.
PMID: 12804822 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12791302&dopt=AbstractToxicol Appl Pharmacol. 2003 Jun 15;189(3):170-179.
Long-term, low-level exposure of guinea pigs and marmosets to sarin vapor in air: lowest observable effect level.
Van Helden HP, Trap HC, Oostdijk JP, Kuijpers WC, Langenberg JP, Benschop HP.
Division of Chemical and Biological Protection, TNO Prins Maurits Laboratory, P.O. Box 45, 2280 AA, Rijswijk, The Netherlands
Realistic scenarios for low-level exposure to nerve agents will often involve exposures over several hours to extremely low doses of agent. In order to expose animals to the lowest controllable concentrations of agent and to increase exposure times until a lowest observable effect level (LOEL) becomes measurable, a validated system was developed for exposing conscious animals to 0.05-1.0 &mgr;g/m(3) (8-160 ppt) of sarin and other nerve agents. Based on cold trapping of sarin from the exposure air, the concentration could be measured semicontinuously, at 4-min time intervals by means of gas chromatography. We found that the LOEL upon a 5-h whole body exposure of guinea pigs and marmosets to sarin vapor corresponds with the measurement of an internal dose by means of fluoride-induced regeneration of sarin from phosphylated binding sites in plasma, mostly BuChE. For guinea pigs the LOEL was observed at Ct = 0.010 +/- 0.002 mg/min/m(3), whereas a Ct of 0.04 +/- 0.01 mg/min/m(3) was established for the LOEL in marmosets. These levels are several orders of magnitude lower than those based on classical measurement of depressed cholinesterase activities. At low exposure levels of guinea pigs and marmosets (The data were addressed in the light of the recently recommended occupational exposure limits to sarin for workers without respiratory protection, which suggests that the exposure limits should be reconsidered if the slightest inhibition of cholinesterases should be prevented.
PMID: 12791302 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12733082&dopt=AbstractInt Arch Occup Environ Health 2003 Mar;76(2):103-10
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12868523&dopt=Abstract
- Respiratory symptoms and lung-function changes with exposure to five substances in aluminium smelters.
Fritschi L, Sim MW, Forbes A, Abramson MW, Benke G, Musk AW, De Klerk NH.
School of Population Health, University of Western Australia, Crawley, WA, 6009, Australia, linf@dph.uwa.edu.au
OBJECTIVES. To determine whether exposure to five different occupational substances contributes to respiratory symptoms in aluminium smelter workers.
METHODS. A cross-sectional survey of 1,615 male employees of two Australian aluminium smelters was conducted in 1995. Subjects underwent spirometry and were asked about respiratory symptoms and the relationship of those symptoms to work. Their job histories were combined with a task exposure matrix to produce individual quantitative measures of cumulative exposure to fluoride, sulphur dioxide, inspirable dust, the benzene-soluble fraction of coal tar pitch volatiles (BSF), and oil mist.
RESULTS. After adjusting for smoking and age, we found that subjects with the highest cumulative exposure to fluoride (>0.16 mg/m(3) years) and inspirable dust (>2.9 mg/m(3) years) were two to four times more likely to report work-related wheeze and chest tightness than were unexposed subjects. Lower prevalence ratios for the same symptoms were seen with sulphur dioxide and BSF. Levels of lung function decreased slightly with exposure to oil mist, but not with cumulative exposure to other substances.
CONCLUSIONS. This study suggests that the relevant causative agents for respiratory symptoms in aluminium smelters are fluoride and inspirable dust.
PMID: 12733082 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12739687&dopt=AbstractJ Clin Pediatr Dent 2003 Spring;27(3):257-60
Estimation of the fluoride concentrations in human breast milk, cow's milk and infant formulae.
Rahul P, Hegde AM, Munshi AK.
Department of Pedodontics and Preventive Dentistry, A.B. Shetty Memorial Institute of Dental Sciences, Deralakatte, Mangalore 575 018, Karnataka, India.
Fluoride has a significant effect on the prevention of dental caries. The major dietary intake of the infants constitutes the breast milk cow's milk and infant milk formulations in which the fluoride contents varies widely. Hence it is important to identify the potential milk source of high fluoride intake in an infant's diet and to evaluate the need for the fluoride supplementation. The aim of the present study was to determine the fluoride concentrations in breast milk, cow's milk, infant formulae and water samples in Mangalore city, India, using fluoride electrode (Orion Model 940900). It was noted that minimal amount of fluoride was found to be present in breast milk and cow's milk samples, while the fluoride content of water samples was found to be below the optimum level. On the contrary the infant formulae were found to have equal or more levels of fluoride.
PMID: 12739687 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12734021&dopt=AbstractJ Can Dent Assoc 2003 May;69(5):286-91
An update on fluorides and fluorosis.
Levy SM.
College of Dentistry, University of Iowa, Preventive and Community Dentistry, Iowa City, Iowa 52242, USA. steven-levy@uiowa.edu
Decisions concerning use of fluoride in its many forms for caries prevention are more complicated now than in the past because of the need to balance these benefits with the risks of dental fluorosis. This article reviews pertinent literature concerning dental fluorosis (definition, appearance, prevalence), pre- and post-eruptive use of fluoride, esthetic perceptions of dental fluorosis, fluoride levels of beverages and foods, the Iowa Fluoride Study, and the U.S. Centers for Disease Control and Prevention's "Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States." Water fluoridation and use of fluoride dentifrice are the most efficient and cost-effective ways to prevent dental caries; other modalities should be targeted toward high-risk individuals.
PMID: 12734021 [PubMed - in process]
- http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12764999&dopt=Abstract
Ethiop Med J. 2003 Jan;41(1):35-44.- Perception of dental fluorosis among adolescents living in urban areas of Ethiopia.
- Fantaye W, Anne A, Asgeir B, Melaku Z, Haymanot RT, Bjorvatn K.
- Faculty of Dentistry, University of Bergen, Norway.
- The objective of the study was to assess the perception of dental fluorosis among adolescents residing in two urban areas in Ethiopia: Addis Ababa (low-fluoride drinking water) and Nazreth (high-fluoride drinking water). Students aged 12-15 years, enrolled in two junior secondary schools in Addis Ababa (n = 161) and two similar schools in Nazreth (n = 177) responded to evaluative statements concerning the appearance of anterior maxillary teeth. Color photographs depicting dental fluorosis (TF score 2, 3, 5 and 7) in maxillary front teeth were used as reference during structured interviews. A majority of the students from Addis Ababa and Nazreth were dissatisfied with the appearance of teeth having TF scores 2 and above. More than 66% of the students from both areas confirmed a need for dental consultation concerning fluorotic teeth with TF 2. As compared to their counterparts in Nazreth, children in Addis Ababa felt more embarrassed with TF score 2 and 3 (p < 0.01). TF scores 5 and 7 were found unacceptable both in Addis Ababa and in Nazreth. Students in Addis Ababa, more frequently than their counterparts in Nazreth, believed (erroneously) that dental fluorosis were related to neglect on the part of the child. The present findings confirm that fluorotic teeth constitute a social problem among junior secondary school children residing in low-fluoride as well as in high-fluoride urban areas in Ethiopia and, thereby, corroborate the public concern for safe drinking water.
- PMID: 12764999 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12729261&dopt=AbstractJ Environ Monit 2003 Apr;5(2):236-40
- Occupational exposure to fluorinated hydrocarbons during refrigeration repair work.
Gjolstad M, Ellingsen DG, Espeland O, Nordby KC, Evenseth H, Thorud S, Skaugset NP, Thomassen Y.
National Institute of Occupational Health, PO Box 8149 Dep., N-0033 Oslo, Norway. Merete.Gjolstad@stami.no
This study describes refrigeration repair workers' occupational exposures to halogenated refrigerants, focusing on difluorochloromethane (HCFC 22), tetrafluoroethane (HFC 134a) and a mixture of tri-, tetra- and pentafluoroethane (R404A) in 30 work operations. Unlike earlier reported studies, the present study includes working procedures involving welding in order to measure possible occupational exposure to decomposition products. The measurements included hydrogen fluoride (HF), hydrogen chloride (HCl), phosgene (COCl2) and volatile organic compounds (VOC). The exposures were assessed during work operations on small-scale cooling installations like refrigerators and freezers. The repair workers' occupational exposures to refrigerants were moderate, and the major part of the exposures were associated with specific working procedures lasting for relatively short periods of time (<20 min). During these exposure events the concentrations were occasionally high (up to 42434 mg m(-3)). Although welding operations lasted only for short periods of time, HF was detected in 9 out of 15 samples when HCFC 22, HFC 134a or R404A had been used. Hydrogen chloride was detected in 3 out of 5 samples in air polluted with HCFC 22. Phosgene was not detected. A large number of VOCs in various concentrations were found during welding. Except for the applied refrigerants, halogenated compounds were only found in one sample.
PMID: 12729261 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12656244&dopt=AbstractChemosphere 2003 Jan;50(3):251-64
- Fluoride toxicity to aquatic organisms: a review.
Camargo JA.
Departamento Interuniversitario de Ecologia, Edificio de Ciencias, Universidad de Alcala, Alcala de Henares, Madrid E-28871, Spain. julio.camargo@uah.es
Published data on the toxicity of fluoride (F-) to algae, aquatic plants, invertebrates and fishes are reviewed. Aquatic organisms living in soft waters may be more adversely affected by fluoride pollution than those living in hard or seawaters because the bioavailability of fluoride ions is reduced with increasing water hardness. Fluoride can either inhibit or enhance the population growth of algae, depending upon fluoride concentration, exposure time and algal species. Aquatic plants seem to be effective in removing fluoride from contaminated water under laboratory and field conditions. In aquatic animals, fluoride tends to be accumulated in the exoskeleton of invertebrates and in the bone tissue of fishes. The toxic action of fluoride resides in the fact that fluoride ions act as enzymatic poisons, inhibiting enzyme activity and, ultimately, interrupting metabolic processes such as glycolysis and synthesis of proteins. Fluoride toxicity to aquatic invertebrates and fishes increases with increasing fluoride concentration, exposure time and water temperature, and decreases with increasing intraspecific body size and water content of calcium and chloride. Freshwater invertebrates and fishes, especially net-spinning caddisfly larvae and upstream-migrating adult salmons, appear to be more sensitive to fluoride toxicity than estuarine and marine animals. Because, in soft waters with low ionic content, a fluoride concentration as low as 0.5 mg F-/l can adversely affect invertebrates and fishes, safe levels below this fluoride/l concentration are recommended in order to protect freshwater animals from fluoride pollution.
PMID: 12656244 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12738270&dopt=AbstractChemosphere 2003 Jul;52(2):455-61
Fluorinated natural products: the biosynthesis of fluoroacetate and 4-fluorothreonine in Streptomyces cattleya.
Murphy CD, Schaffrath C, O'Hagan D.
School of Chemistry, Centre for Biomolecular Sciences, North Haugh, St Andrews, KY16 9ST, Fife, UK
Organofluorine compounds are rare in Nature, with only a handful known to be produced by some species of plant and two microorganisms. Consequently, the mechanism of enzymatic carbon-fluorine bond formation is poorly understood. The bacterium Streptomyces cattleya biosynthesises fluoroacetate and 4-fluorothreonine as secondary metabolites and is a convenient system to study the biosynthesis and enzymology of fluorometabolite production. Using stable-isotope labelled precursors it has been shown that there is a common intermediate in the biosynthesis of the fluorometabolites, which has recently been identified as fluoroacetaldehyde. Studies with cell-free extracts of S. cattleya have identified two enzymes, an aldehyde dehydrogenase and a threonine transaldolase, that are involved in the biotransformation of fluoroacetaldehyde to fluoroacetate and 4-fluorothreonine.
PMID: 12738270 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12661183&dopt=AbstractJ Occup Environ Med 2003 Mar;45(3):260-70
Epidemiologic assessment of worker serum perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) concentrations and medical surveillance examinations.
Olsen GW, Burris JM, Burlew MM, Mandel JH.
Medical Dept., 3M Company, Mail Stop 220-3W-05, St. Paul, MN 55144, USA. gwolsen@mmm.com
Perfluorooctanesulfonyl fluoride (POSF, C8F17SO2F) is used to create applications for surfactants and paper, packaging, and surface (e.g., carpets, textiles) protectants. Such POSF-based products or their residuals may degrade or metabolize to PFOS (C8F17SO3-). PFOS concentrates in liver and serum and results in hypolipidemia as an early effect of cumulative dosages. Male and female employees of two perfluorooctanyl-manufacturing locations (Antwerp, Belgium and Decatur, Alabama) participated in a periodic medical surveillance program that included hematology, clinical chemistry, thyroid hormone, and urinalysis testing. Serum concentrations of PFOS and perfluorooctanoate (PFOA, C7F15CO2-, used as a fluoropolymer emulsifier) were measured via mass spectrometry methods. The mean serum PFOS and PFOA concentrations for 263 Decatur employees were 1.32 parts per million (ppm; geometric mean 0.91, range 0.06-10.06 ppm) and 1.78 ppm (geometric mean 1.13, range 0.04-12.70 ppm), respectively. Mean concentrations were approximately 50% lower among 255 Antwerp workers. Adjusting for potential confounding factors, there were no substantial changes in hematological, lipid, hepatic, thyroid, or urinary parameters consistent with the known toxicological effects of PFOS or PFOA in cross-sectional or longitudinal analyses of the workers' measured serum fluorochemical concentrations.
PMID: 12661183 [PubMed - in process]
- Environ Technol. 2003 Jun;24(6):687-92.
- Behavior of fluorine and chlorine in Spanish coal fired power plants with pulverized coal boilers and fluidized bed boiler.
- Lopez-Vilarino JM, Fernandez-Martinez G, Turnes-Carou I, Muinategui-Lorenzo S, Lopez-Mahia P, Prada-Rodriguez D.
- Department of Analytical Chemistry, University of A Coruna, Zapateira s/n. E-15071 A Coruna, Spain.
- Behavior and contents of fluorine and chlorine in coal feedstock, combustion wastes (slag and fly ash) and emissions were studied in five conventional coal fired power plants and in a fluidized bed coal power plant. The halide levels found in the used coal were quite low. Mass balances and emission factors were calculated. The volatility of these elements makes the gaseous emission the main target between the residues. The influence of combustion parameters is not clearly established. Several analytical techniques (ion selective electrodes, capillary electrophoresis and ion chromatography) are employed to determinate the halide concentration in the different samples taken in the power plants studied (coal, slag, fly ash and flue gases).
- PMID: 12868523 [PubMed - in process]
- http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12586148&dopt=Abstract
- Chemosphere. 2003 Apr;51(2):153-61.
Unique bioconcentration characteristics of new aryl fluoroalkyl ethers in common carp (Cyprinus carpio).
- Yakata N, Sudo Y, Yakabe Y, Tadokoro H, Fukui H, Sanechika K, Ikeda M. Chemicals Evaluation and
- Research Institute, Kurume Laboratory, 19-14 Chuo-machi, Kurume, Fukuoka 830-0023, Japan. yakata-noaki@ceri.jp
- The bioconcentration factors (BCFs) of seven new aryl fluoroalkyl ethers--four bis-4-tetrafluoroethoxyphenyl-type (bis-type) compounds and three mono-4-tetrafluoroethoxyphenyl-type (mono-type) compounds--were obtained by bioconcentration tests using common carp. The BCFs of 4 of the 7 ethers were higher than 5000, indicating their high bioconcentration potential. The bioconcentration characteristics of the bis-type compounds were different from those of the mono-type compounds and non-fluoro diphenylmethanes with a similar skeleton structure to the bis-type compounds, in taking longer to reach a plateau and having a slower elimination rate and in their distribution patterns in the fish body. The BCF of 1 bis-type compound was much higher than the value predicted by an accepted correlation equation between BCF and P(ow). In addition, the logP(ow) of the bis-type compounds calculated by commercially available computer software was remarkably different from that measured.
- PMID: 12586148 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12666917&dopt=Abstracthttp://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12688488&dopt=Abstract
- Environ Sci Technol. 2003 Mar 1;37(5):888-91.
- Human donor liver and serum concentrations of perfluorooctanesulfonate and other perfluorochemicals.
- Olsen GW, Hansen KJ, Stevenson LA, Burris JM, Mandel JH.
- 3M Medical Department, 220-3W-05, St. Paul, Minnesota 55144, USA. gwolsen@mmm.com
- Perfluorooctanesulfonate (PFOS, CaF17SO3-) has been identified in the serum of nonoccupationally exposed humans and in serum and liver tissue in wildlife. The purpose of this investigation was to determine whether PFOS liver concentrations in humans are comparable to the approximate 30 ng/mL average serum concentrations reported in nonoccupationally exposed subjects. Thirty-one donors (16 male and 15 female, age range 5-74) provided serum and/or liver samples for analysis of PFOS and three other fluorochemicals: perfluorosulfonamide (PFOSA, C8F17SO2NH2), perfluorooctanoate (PFOA, C7F15CO2-), and perfluorohexanesulfonate (PFHxS, C6F13SO3-). Both sera and liver samples were extracted by ion-pair extraction and quantitatively assayed using high-performance liquid chromatography electrospray tandem mass spectrometry. Liver PFOS concentrations ranged from <4.5 ng/g (limit of quantitation, LOQ)to 57.0 ng/g. Serum PFOS concentrations ranged from <6.1 ng/mL (LOQ) to 58.3 ng/mL. Among the 23 paired samples, the mean liver to serum ratio was 1.3:1 (95% confidence interval 0.9:1-1.7:1). This liver to serum ratio is comparable to that reported in a toxicological study of cynomolgus monkeys, which had liver and serum concentrations 2-3 orders of magnitude higher than observed in these human donors. This information may be useful in human risk characterization for PFOS. Liver to serum ratios were not estimated for PFOA, PFHxS, and PFOSA as 90% of the human donor liver samples were determined to be less than the LOQ.
- PMID: 12666917 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12660366&dopt=AbstractToxicol Sci 2003 Apr;72(2):363-8
- Antioxidant defense system and lipid peroxidation in patients with skeletal fluorosis and in fluoride-intoxicated rabbits.
Reddy GB, Khandare AL, Reddy PY, Rao GS, Balakrishna N, Srivalli I.
National Institute of Nutrition (ICMR), Hyderabad 500 007, India.
Fluorosis is a serious public health problem in many parts of the world where drinking water contains more than 1 ppm of fluoride. The main manifestations of skeletal fluorosis are crippling bone deformities, spinal compressions, and restricted movements of joints. Although fluorosis is irreversible, it could be prevented by appropriate and timely intervention through understanding the process at biochemical and molecular levels. As in the case of many chronic degenerative diseases, increased production of reactive oxygen species (ROS) and lipid peroxidation has been considered to play an important role, even in the pathogenesis of chronic fluoride toxicity. However, there is inconclusive proof for an altered oxidative stress and antioxidant balance in fluorosis, and the existing data are not only conflicting but also contradictory. In the present communication we have evaluated the antioxidant defense system (both enzymatic and nonenzymatic) and lipid peroxidation in both humans from an endemic fluorosis area (5 ppm fluoride in the drinking water) and in rabbits receiving water with 150 ppm of fluoride for six months. There was no significant difference in lipid peroxidation, glutathione, and vitamin C in the blood of human fluorotic patients and fluoride-intoxicated rabbits as compared to respective controls. Neither were there any changes in the activities of catalase, superoxide dismutase, glutathione peroxidase, or glutathione S-transferase in the blood due to fluoride intoxication (of rabbits) or fluorosis in humans. The results together do not subscribe to oxidative stress theory in fluorosis. Thus, in the absence of clear proof of oxidative damage and to counter toxic effects of fluoride through supplementation of antioxidants, extensive investigations are needed to conclusively prove the role of oxidative stress in skeletal fluorosis.
PMID: 12660366 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12654037&dopt=AbstractPhysiol Plant 2003 Mar;117(3):368-375
Fluoride inhibits root water transport and affects leaf expansion and gas exchange in aspen (Populus tremuloides) seedlings.
Kamaluddin M, Zwiazek JJ.
Department of Renewable Resources, 4-42 Earth Sciences Bldg., University of Alberta, Edmonton, Alberta T6G 2E3, Canada.
The effects of sodium fluoride (0.3, 5 and 10 mM NaF) on root hydraulic conductivity, and gas exchange processes were examined in aspen (Populus tremuloides Michx.) seedlings grown in solution culture. A long-term exposure of roots to NaF significantly decreased root hydraulic conductivity (Lp) and stomatal conductance ( gs). Root absorbed NaF significantly affected electrolyte leakage in leaf tissues and substantially restricted leaf expansion. NaF did not significantly affect leaf chlorophyll contents but decreased net photosynthesis (Pn). A short-term exposure of excised roots to 5 mM NaF and KF significantly decreased root water flow (Qv) with a concomitant decline in root respiration and reduced gs when applied through intact roots or excised stems. The same molar concentration of NaCl also decreased Qv and gs in intact seedlings, but to a lesser extent than NaF or KF, and did not significantly affect root respiration. The results suggest that fluoride metabolically inhibited Qv or Lp, probably by affecting water channel activity. We suggest that the metabolic inhibition of Lp by root-absorbed fluoride affected gas exchange and leaf expansion in aspen seedlings.
PMID: 12654037 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12630439&dopt=AbstractScand J Work Environ Health 2003 Feb;29(1):71-7
Prolonged respiratory symptoms caused by thermal degradation products of freons.
Piirila P, Espo T, Pfaffli P, Riihimaki V, Wolff H, Nordman H.
Department of Occupational Medicine, Finnish Institute of Occupational Health, Helsinki, Finland. paivi.piirila@hus.fi
OBJECTIVES: The chlorofluorocarbons (CFC) used in refrigeration systems decompose on heating and produce substances that are highly irritating to the airways (eg, chlorine, carbonyl fluoride, and hydrogen fluoride). This study examined persistent respiratory symptoms among several workers exposed to thermal decomposition products of CFC.
METHODS: Seven patients with respiratory symptoms caused by inadvertent exposure to thermal decomposition products of CFC in a restaurant kitchen or during refrigerator repair were studied with the use of spirometry, peak flow follow-up, and histamine challenge tests. Three patients also underwent bronchoscopy and bronchoalveolar lavage.
RESULTS: In five of the cases, cough or dyspnea lasted longer than 1 month; for three of the five, the symptoms lasted more than 4 years. Three cases showed increased bronchial hyperreactivity, and two of the three had increased diurnal peak flow variation. Three patients fulfilled the criteria for acute irritant-induced asthma or reactive airway dysfunction syndrome. One case exhibited bronchiolitis while, for the other six, the clinical picture was consistent with bronchitis.
CONCLUSIONS: The studied cases indicate that the thermal decomposition products of CFC used in refrigerators may cause irritant-induced airway diseases of long duration.
PMID: 12630439 [PubMed - in process]
- Chemosphere. 2003 Feb;50(6):763-9.
- Study on fluoride emission from soils at high temperature related to brick-making process.
- Xie ZM, Wu WH, Xu JM.
- College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029, PR China. zhmxie@zju.edu.cn
- Characteristics of fluoride emission from 12 soils at temperatures of 400-1,100 degrees C related to the brick-making process were studied. The results obtained in this study indicate that fluoride emission as gaseous HF and SiF4 was related to the firing temperature, soil total fluoride content, soil composition and calcium compounds added to soils. Soils began to release fluoride at temperatures between 500 and 700 degrees C. Marked increases of the average fluoride mission rate from 57.2% to 85.4% of soil total fluoride were noticed as the heating temperature was increased from 700 to 1,100 degrees C. It was found that the major proportion (over 50%) of the soil total fluoride was emitted from soils at approximate 800 degrees C. The amount of fluoride released into the atmosphere when heated depended on the total fluoride contents in the soils. Correlation analysis showed that the soil composition, such as cation exchange capacity, exchangeable calcium and CaCO3, had some influence on fluoride emission below 900 degrees C, but had no influence at temperatures above 900 degrees C. Addition of four calcium compounds (CaO, CaCO3, Ca(OH)2, and CaSO4) at 1.5% by weight raised the temperature at which fluoride began to be released to 700 degrees C. The greatest decrease in fluoride emission among the four calcium compound treatments was found with CaCO3.
- PMID: 12688488 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12595885&dopt=Abstract
J Expo Anal Environ Epidemiol 2003 Jan;13(1):66-73Fluoride concentrations in three types of commercially packed tea drinks in Taiwan.
Lung SC, Hsiao PK, Chiang KM.
[1] Department of Public Health, Chung Shan Medical University, Taichung, Taiwan, ROC
[2] Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan, ROC.
Tea is a popular drink around the world. It is also one of the major sources of fluoride intake. The objectives of this study were to assess fluoride concentrations in popular non-, semi-, and full-fermented tea drinks sold on the Taiwan market. Concentration differences among three types of commercially available tea drinks (tea leaf, tea bag, and packaged tea beverage) were explored. Several influential factors in intake concentrations were evaluated. The acute threshold intake (ATI) and allowable daily intake (ADI) of those tea drinks were also estimated. For each commercial type, samples from the most popular tea in one particular fermentation degree (non, semi, and full) were randomly purchased and analyzed for fluoride concentrations. Fluoride levels in different rounds of tea, in different containers, and with different ratios of water and tea leaf were also assessed. In total, 132 tea samples were analyzed. The mean fluoride concentrations in leaf tea without the first round, leaf tea with the first round, bagged tea, and packaged tea were 7.04, 7.79, 5.37, and 25.7 mg/l, respectively. Most of the intake concentrations in those samples exceeded 4 mg/l F, the lower bound of fluoride levels reported in the literatures to be associated with a lower IQ in children and a higher risk of bone fracture. Fluoride concentrations in packaged tea were the highest among the three types of commercially available tea. For studied leaf and bagged tea, almost a constant amount of fluoride was infused from the same amount of tea leaf regardless of the water volume. Besides this, making tea with glass or pottery tea makers would not affect fluoride intake concentrations. Acute intoxication is unlikely to occur. However, tea lovers in high fluoride content areas shall consider limit their consumption of tea drinks to avoid potential chronic effects.
PMID: 12595885 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12564917&dopt=AbstractEnviron Sci Technol 2003 Jan 15;37(2):418-22
Decomposition of environmentally persistent trifluoroacetic acid to fluoride ions by a homogeneous photocatalyst in water.
Hori H, Takano Y, Koike K, Takeuchi K, Einaga H.
National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba West, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan. h-hori@aist.go.jp
Decomposition of trifluoroacetic acid (TFA) was achieved with a tungstic heteropolyacid photocatalyst H3PW12O40*6H2O in order to develop a technique for measures against TFA stationary sources. This is the first example of C-F bond cleavage in an environmentally harmful perfluoromethyl-group-containing compound using a homogeneous photocatalyst. The catalytic reaction proceeds in water at room temperature under UV-visible light irradiation in the presence of oxygen. The system produces only F- ions and CO2; the (mole of formed F-)/(mole of decomposed TFA) and (mole of formed CO2)/(mole of decomposed TFA) ratios were 2.91 and 2.09, respectively. GC/MS measurements showed no trace of other species such as environmentally undesirable CF4, which is the most stable perfluorocarbon and has a very high global warming potential. When the (initial TFA)/(initial catalyst) molar ratio was 20:1, the turnover number of TFA decomposition reached 5.58 by 72 h of irradiation, accompanying with no catalyst degradation. The catalytic reaction mechanism can be explained by a redox reaction between the catalyst and TFA, involving a photo-Kolbe process.
PMID: 12564917 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12505437&dopt=AbstractToxicol Lett 2003 Jan 31;137(1-2):111-20
Aluminium and fluoride contents of tea, with emphasis on brick tea and their health implications.
Wong MH, Fung KF, Carr HP.
Department of Biology, Institute for Natural Resources and Environmental Management, Hong Kong Baptist University, Kowloon Tong, Hong Kong
Tea plant takes up a large quantity of aluminium (Al) and fluoride (F) from acidic soils. It has been known that fluorosis can be developed for people who consume a large quantity of tea made from brick tea, a low quality tea consisting mainly of old tea leaves in China. In addition, it has been claimed that Alzheimer's disease (AD) is linked with the Al content in the human brain. Therefore, the high Al content in tea, especially brick tea is also a concern. This article reviews the basis background on tea including classification, growth conditions, types of tea leaves and their production, and processing of tea. Special emphasis is made on the transfer of Al and F from soil to tea plant and then to tea liquor. Health implications of drinking a large quantity of tea liquor especially those made from brick tea are discussed. Recommendations are suggested to reduce the uptake of these two elements by tea plant, and lower their contents in tea products.
PMID: 12505437 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12901167&dopt=Abstract
- Environ Geochem Health. 2003 Jun;25(2):219-32.
- Aluminium and fluoride concentrations of three tea varieties growing at Lantau Island, Hong Kong.
- Fung KF, Zhang ZQ, Wong JW, Wong MH.
- Institute for Natural Resources and Environmental Management, Department of Biology, 224 Waterloo Road, Hong Kong Baptist University, Kowloon Tong, Hong Kong, People's Republic of China.
- The present project aims to investigate aluminium (Al) and fluoride (F) contents in teas (Camellia sinensis (L.) O. Kuntze). Three different commercial tea varieties: Assam variety and two China sub-varieties, a large leafed variety and small leafed variety, were collected in two tea gardens of Lantau Island tea plantation of Hong Kong. In general, high concentrations of Al and F were accumulated in the mature leaves (15.3 and of 2.07 g kg-1 respectively). Among the three varieties, 'the small leafed' variety exhibited the highest Al and F contents followed by the 'large leafed' variety whereas the Assam variety had the lowest Al and F concentrations in its tea bushes. Tea products from a plantation were also analysed and it was noted that black tea had higher Al and F concentrations than green tea. The amount of Al and F released into tea liquor was also tested and the results showed that higher concentrations of Al and F were released into tea liquor under repeated infusion method than continuous infusion method.
- PMID: 12901167 [PubMed - in process]
- http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12505437&dopt=Abstract
Toxicol Lett 2003 Jan 31;137(1-2):111-20
Aluminium and fluoride contents of tea, with emphasis on brick tea and their health implications.
Wong MH, Fung KF, Carr HP.
Department of Biology, Institute for Natural Resources and Environmental Management, Hong Kong Baptist University, Kowloon Tong, Hong Kong. mhwong@hkbu.edu.hk
Tea plant takes up a large quantity of aluminium (Al) and fluoride (F) from acidic soils. It has been known that fluorosis can be developed for people who consume a large quantity of tea made from brick tea, a low quality tea consisting mainly of old tea leaves in China. In addition, it has been claimed that Alzheimer's disease (AD) is linked with the Al content in the human brain. Therefore, the high Al content in tea, especially brick tea is also a concern. This article reviews the basis background on tea including classification, growth conditions, types of tea leaves and their production, and processing of tea. Special emphasis is made on the transfer of Al and F from soil to tea plant and then to tea liquor. Health implications of drinking a large quantity of tea liquor especially those made from brick tea are discussed. Recommendations are suggested to reduce the uptake of these two elements by tea plant, and lower their contents in tea products.
Publication Types:
- Review
- Review, Tutorial
PMID: 12505437 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12615125&dopt=AbstractFood Chem Toxicol 2003 Apr;41(4):535-42
Brick tea fluoride as a main source of adult fluorosis.
Cao J, Zhao Y, Liu J, Xirao R, Danzeng S, Daji D, Yan Y.
Tea and Health Laboratory, Xiangya School of Medical Sciences, Central South University, Changsha 410078, Hunan, PR China
An epidemiological survey was conducted in Naqu County, Tibet in September 2001 to investigate the manifestations of fluorosis in adults caused by the habitual consumption of brick tea. Profiles were obtained for the total daily fluoride intake, environmental fluoride levels and average urinary fluoride concentration, and a physical examination and a skeletal radiographic study were conducted. One hundred and eleven 30-78-year-old adults were enrolled. It was found that the fluoride level of water sources in Naqu County was 0.10+/-0.03 mg/l; no evidence of fluoride air pollution was found, but the brick tea water processed foods-zamba and buttered tea-had fluoride contents of 4.52+/-0.74 mg/kg and 3.21+/-0.65 mg/l, respectively. The adult daily fluoride intake reached 12 mg, of which 99% originated from the brick tea-containing foods. The positive rate of clinical symptoms by physical examination was 89%; furthermore, 42 of the 111 subjects were diagnosed by X-ray. The positive examination rate was 83%. Although the osteosclerosis-type skeletal fluorosis (overall increased bone matrix density) affected 74%, arthropathy and arthritis affected a significant number of the patients, resulting in functional disability. The results suggest that this brick tea-type fluorosis had even more severe adverse effects on human health compared with both the water-type and coal combustion-type fluorosis that occurred in other areas of China.
PMID: 12615125 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12503760&dopt=AbstractEnviron Toxicol Chem 2003 Jan;22(1):161-6
Toxicity of aqueous and sediment-associated fluoride to freshwater organisms.
Metcalfe-Smith JL, Holtze KE, Sirota GR, Reid JJ, de Solla SR.
Aquatic Ecosystem Impacts Research Branch, National Water Research Institute, P.O. Box 5050, 867 Lakeshore Road, Burlington, Ontario L7R 4A6, Canada. janice.smith@ec.gc.ca
Inorganic fluorides were declared toxic under the Canadian Environmental Protection Act in 1993 based on their potential to cause long-term harmful effects in aquatic and terrestrial ecosystems, but information on the toxicity of sediment-associated fluoride to freshwater benthic organisms was considered incomplete. The purpose of this study was to determine the toxicity of aqueous and sediment-associated fluoride to several species of freshwater organisms and to determine if toxic effects could be expected under environmentally realistic exposures. Toxicity of fluoride (as NaF) in short-term (48-96-h) lethality tests was greatest for the amphipod Hyalella azteca (median lethal concentration [LC50] = 14.6 mg F-/L), followed by the mayfly Hexagenia limbata (32.3), the midge Chironomus tentans (124.1), the fathead minnow Pimephales promelas (262.4), and the cladoceran Daphnia magna (282.8). Relative toxicity in long-term (10-28-d) growth and survival tests in spiked sediment was similar. Hyalella azteca was the most sensitive species for growth (25% inhibitory concentration [IC25] = 290.2 microg F-/g), followed by C. tentans (661.4), H. limbata (1,221.3), and P. promelas (>5,600); H. azteca was also the most sensitive species for survival (LC50 = 1,114.6 microg F-/g), followed by H. limbata (1,652.2) and P. promelas and C. tentans (>5,600 for both). Concentrations of fluoride measured in sediments near some industrial point sources exceed some of these toxicity thresholds. Fluoride is highly mobile in aquatic systems and could potentially reach toxic levels in the water column during dredging to remove fluoride-contaminated sediment.
PMID: 12503760 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12531270&dopt=AbstractWater Res 2003 Feb;37(4):884-90
Chemistry of trace elements in coalbed methane product water.
McBeth I, Reddy KJ, Skinner QD.
Department of Renewable Resources, College of Agriculture, University of Wyoming, PO Box 3354, Laramie, WY 82071, USA.
Extraction of methane (natural gas) from coal deposits is facilitated by pumping of aquifer water. Coalbed methane (CBM) product water, produced from pumping ground water, is discharged into associated unlined holding ponds. The objective of this study was to examine the chemistry of trace elements in CBM product water at discharge points and in associated holding ponds across the Powder River Basin, Wyoming. Product water samples from discharge points and associated holding ponds were collected from the Cheyenne River (CHR), Belle Fourche River (BFR), and Little Powder River (LPR) watersheds during the summers of 1999 and 2000. Samples were analyzed for pH, Al (aluminum), As (arsenic), B (boron), Ba (barium), Cr (chromium), Cu (copper), F (fluoride), Fe (iron), Mn (manganese), Mo (molybdenum), Se (selenium), and Zn (zinc). Chemistry of trace element concentrations were modeled with the MINTEQA2 geochemical equilibrium model. Results of this study show that pH of product water for three watersheds increased in holding ponds. For example the pH of CBM product water increased from 7.21 to 8.26 for LPR watershed. Among three watersheds, the CBM product water exhibited relatively less change in trace element concentrations in CHR watershed holding ponds. Concentration of dissolved Al, Fe, As, Se, and F in product water increased in BFR watershed holding ponds. For example, concentration of dissolved Fe increased from 113 to 135 microg/L. Boron, Cu, and Zn concentrations of product water did not change in BFR watershed holding ponds. However, concentration of dissolved Ba, Mn, and Cr in product water decreased in BFR watershed holding ponds. For instance, Ba and Cr concentrations decreased from 445 to 386 microg/L and from 43.6 to 25.1 microg/L, respectively. In the LPR watershed, Al, Fe, As, Se, and F concentrations of product water increased substantially in holding ponds. For example, Fe concentration increased from 192 to 312 microg/L. However, concentration of dissolved Ba, Mn, Cr, and Zn decreased in holding ponds. Geochemical modeling calculations suggested that observed increase of Al and Fe concentrations in holding ponds was due to increase in concentration of Al(OH)(4)(-) and Fe(OH)(4)(-) species in water which were responsible for pH increases. Decreases in Ba, Mn, Cr, and Zn concentrations were attributed to the increase in pH, resulting in precipitates of BaSO(4) (barite), MnCO(3) (rhodochrosite), Cr(OH)(2) (chromium hydroxide), and ZnCO(3) (smithsonite) in pond waters, respectively.
PMID: 12531270 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12628786&dopt=AbstractJ Hazard Mater 2003 Mar 17;98(1-3):183-90
- Effectiveness of cement-based systems for stabilization and solidification of spent pot liner inorganic fraction.
Silveira BI, Dantas AE, Blasques JE, Santos RK.
Chemical Engineering Department, Federal University of Para, Para, Brazil
Approximately 7000t of spent pot liner (SPL) wastes are generated annually from activities associated with Alumi;nio Brasileiro S.A. (ALBRAS) plant located at Barcarena, Para state, Brazil. The inorganic fraction of SPL contains high level of toxic compounds like cyanide and fluoride; its safe disposal has been the subject of serious discussions in Brazil. This study evaluated the option of a cement-based stabilization/solidification system as an effective means for safe disposal of SPL inorganic fraction in the field. The studies were carried out with concrete hexagonal blocks manufactured with a constant mass of 10% (w/w) of waste, 20% (w/w) of cement, and varied percentages of water, coarse aggregate, sand, and additives. The concrete matrices porosity and compressive strength were controlled by using microsilica (MS) and superplaticizer (SP). The results showed an average pH values for the SPL inorganic fraction and fragmented blocks of 10.2 and 11.1, respectively. Mixing the waste with concrete ingredients the solidification/stabilization effectiveness for the leachable cyanides and fluorides were of 59.33 and 57.95%, respectively. The results showed that the water/cement (W/C) ratio reduction through superplasticizer addition improved the compressive strength and the required value of 35MPa was reached with blocks manufactured with 10 and 15% (weight of cement) of microsilica, after 28 days of curing time.
PMID: 12628786 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12616333&dopt=AbstractCalcif Tissue Int 2003 Mar 6; [epub ahead of print]
Bone Mineral Density of the Spine and Femur in Early Postmenopausal Turkish Women with Endemic Skeletal Fluorosis.
Y?ld?z M, Akdo?an M, Tamer N, Oral B.
Department of Nuclear Medicine, Suleyman Demirel University, School of Medicine, Isparta/Turkey.
The aim of this prospective, comparative study was to investigate the bone mineral density (BMD) changes in a group of early postmenopausal Turkish women with endemic skeletal fluorosis and to study effects of endemic fluorosis on BMD. Bone mineral density of L2-L4 vertebra, femur neck, femur trochanter, and Ward's triangle were measured in 45 female patients with endemic skeletal fluorosis and 41 age-matched controls by dual X-ray absorbtiometry (DXA). The BMD of L2-L4 vertebra and Ward's triangle were higher in the endemic fluorosis group than in the control group (P <0.001). Patients with endemic fluorosis had higher femur neck and femur trochanter BMDs than did controls (P <0.01 and P <0.05, respectively). There was a positive correlation between serum fluoride content and BMD at the spine (r = 0.345, P = 0.001), femoral neck (r = 0.274, P = 0.011), Ward's triangle (r = 0.295, P = 0.006), and trochanter (r = 0.217, P = 0.045). In conclusion, higher bone mineral density levels were seen in early postmenopausal women with endemic skeletal fluorosis. BMD measurement is a tool in the diagnosis and management of this preventable crippling disease.
PMID: 12616333 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12605625&dopt=AbstractInt J Paediatr Dent 2003 Mar;13(2):85-92
- The prevalence and severity of dental fluorosis among 12-year-old schoolchildren in Jordan.
Hamdan MA.
Faculty of Dentistry, University of Jordan, Amman, Jordan.
OBJECTIVES: To assess dental fluorosis, provide base-line data among Jordanian children and to compare fluorosis in incisor teeth between areas with different fluoride levels.
DESIGN: Cross-sectional study among school children.
SAMPLE AND METHODS: A sample of 1878 subjects aged 12 years, 940 boys and 938 girls, were randomly selected from 128 schools in urban (69 schools) and rural (59 schools) areas. The Thylstrup & Fejerskov (TF) index was used to record the dental fluorosis on the labial surfaces of incisors.
RESULTS: A total of 18.5% of the children examined showed dental fluorosis. The difference in fluorosis between males (17%) and females (20%) was not statistically significant (P > 0.05). Children in rural areas had a higher prevalence of fluorosis (31.8%) than their counterparts in urban areas (11.3%), a difference that was statistically significant (P < 0.01).
CONCLUSIONS AND RECOMMENDATIONS: Findings suggest that there is a need for continued monitoring of mottling and further investigation into the fluoride intake from all sources in Jordan. However, there is a need to change the drinking water supplies in the southern region of Jordan. Active steps should also be taken to suppress emissions of vapours high in fluoride from phosphate plants to within acceptable limits.
PMID: 12605625 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12602382&dopt=AbstractPrescrire Int 2003 Feb;12(63):18
No Author or Abstract available
Fluoride osteosis with niflumic acid.
PMID: 12602382 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12493195&dopt=AbstractSci Total Environ 2003 Jan 1;301(1-3):175-85
Volcanogenic fluorine in rainwater around active degassing volcanoes: Mt. Etna and Stromboli Island, Italy.
Bellomo S, D'Alessandro W, Longo M.
Dipartimento CFTA, Universita di Palermo, via Archirafi 36, 90123, Palermo, Italy
Many studies have assessed the strong influence of volcanic activity on the surrounding environment. This is particularly true for strong gas emitters such as Mt. Etna and Stromboli volcanoes. Among volcanic gases, fluorine compounds are potentially very harmful. Fluorine cycling through rainwater in the above volcanic areas was studied analysing more than 400 monthly bulk samples. Data indicate that only approximately 1% of fluorine emission through the plume is deposited on the two volcanic areas by meteoric precipitations. Although measured bulk rainwater fluorine fluxes are comparable to and sometimes higher than in heavily polluted areas, their influence on the surrounding vegetation is limited. Only annual crops, in fact, show some damage that could be an effect of fluorine deposition, indicating that long-living endemic plant species or varieties have developed some kind of resistance.
PMID: 12493195 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12602633&dopt=AbstractEnviron Monit Assess 2003 Mar;82(3):311-20
Spatial patterns of nitrate, chloride, sulfate, and fluoride concentrations in the Woodbine Aquifer of north-central Texas.
Hudak PF, Sanmanee S.
Department of Geography and Environmental Science Program, University of North Texas, Denton, Texas, USA. hudak@unt.edu
A geographic information system was used to map and analyze nitrate, chloride, sulfate, and fluoride concentrations in 110 wells tapping the Woodbine Aquifer. The study area, covering nine counties in north-central Texas, includes large percentages of both urban and agricultural land uses. Land use maps were compared with solute concentration data, and statistics were applied to detect associations between solutes, well depth, and land use. Anthropogenic sources such as fertilizer applications and natural sources such as gypsum, lignite, and clay deposits controlled nitrate, chloride, and sulfate concentrations, each inversely correlated with well depth. However, only one nitrate observation--from a shallow well in the aquifer's outcrop zone--surpassed the maximum contaminant level (MCL) of 44.3 mg L(-1). By comparison, nearly half of the sulfate and several of the chloride observations surpassed the MCL of 250 mg L(-1) for each of those ions. Volcanic ash deposits influenced fluoride concentrations, which directly correlated with well depth. There were no statistically significant associations between solute concentrations and land use. Low recharge rates and confining layers have mitigated anthropogenic impacts on solute levels in the aquifer.
PMID: 12602633 [PubMed - in process]
- http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15270349
Indian J Environ Health. 2003 Apr;45(2):155-60.
- Nitrate and fluoride levels in ground waters of Davanagere Taluka in Karnataka.
Manjappa S, Basavarajappa BE, Desai GP, Hotanahalli SS, Aravinda HB.
Environmental Science and Technology Study Centre, Bapuji Institute of Engineering and Technology, Davanagere 577 004, Karnataka, India.
The quality of ground water supplies in Davanagere Taluk, situated in central part of Karnataka has been investigated with respect to pH, dissolved solids, chlorides, nitrates and fluorides. The levels of pH, dissolved solids and chlorides were found within the safe limits as prescribed by BIS, for more than 95% of the samples. Out of the 61 different borewell samples analysed, selected from different areas of Davanagere taluk, 26% of the samples are found to contain fluorides less than 0.50 PPM (lower safe limit prescribed by BIS) and 11.5% of the samples are found to contain more than 1.5 PPM of fluorides (higher safe limit prescribed by BIS). Further, it was also found during study that, 16.00% of the borewell samples analyzed, were found to contain more than 100.00 PPM of nitrates (measured as NO3 mg/L, safe limit prescribed by BIS). The values of fluorides and nitrates observed in different samples were in the range of 0.19 - 2.06 PPM and 0.08 - 308 PPM, respectively.
PMID: 15270349 [PubMed - indexed for MEDLINE]
- http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12554539&dopt=Abstract
J Toxicol Environ Health A 2003;66(4):305-25
Ecotoxicological Risks Associated with Land Treatment of Petrochemical Wastes. I. Residual Soil Contamination and Bioaccumulation by Cotton Rats (Sigmodon hispidus).
Schroder J, Basta N, Payton M, Wilson J, Carlson R, Janz D, Lochmiller R.
College of Nursing and Institute of Agricultural, Rural, and Environmental Health (I.ARE.H), University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Petrochemical waste contains both organic and inorganic contaminants that can pollute soil and may pose significant ecological risks to wildlife. Petrochemical waste typically is disposed of in land treatment units, which are widespread throughout Oklahoma and the United States. Few studies have been conducted evaluating possible toxicity risks to terrestrial organisms residing on these units. In this study, the extent of soil contamination with fluoride (F), metals, and organic hydrocarbons, the bioaccumulation of F and metals in cotton rats (Sigmodon hispidus), the relationship between contaminants in soil and in tissues of cotton rats, and the level of potentially toxic polycyclic aromatic hydrocarbons (PAHs) in soil were determined on land treatment units. Over a 2-yr period, cotton rats and soils were collected and analyzed from 5 land treatment and matched reference units. The number of land treatment units with soil metal contamination (in parentheses) included: Cr, Cu, Pb (5); Al, As, Ni, Sr, Zn (4); Ba (3); and Cd, V (2). The number of land treatment units with soil PAH contamination (in parentheses) were naphthalene, phenanthrene, benzo[g,h,i]perylene (3); acenaphthene, anthracene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[a]pyrene, indeno[1,2,3-c,d]pyrene, dibenz[a,h]anthracene (2); and acenaphthylene, fluorene, fluoranthene, benzo[k]fluoranthene (1). Total PAH and total petroleum hydrocarbons (TPH) were elevated at all five land treatment units. Mean sums of benzo[a]pyrene (BaP) equivalents (BaPequiv ) were not affected on
PMID: 12554539 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12545357&dopt=AbstractBull Environ Contam Toxicol 2003 Feb;70(2):262-7
No Abstract available
Removal of zinc and fluoride ions from industrial waste water plants around Cairo.
Abdel-Halim SH, Shehata AM, El-Shahat MF.
Ain Shams University, Faculty of Science, Chemistry Department, Cairo, Egypt.
PMID: 12545357 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12543981&dopt=AbstractScience 2003 Jan 23; [epub ahead of print]
Spectroscopic Determination of the OH- Solvation Shell in the OH-{middle dot}(H2O)n Clusters.
Robertson WH, Diken EG, Price EA, Shin JW, Johnson MA.
Sterling Chemistry Laboratory, Department of Chemistry, Yale University, Post Office Box 208107, New Haven, CT 06520-8107, USA.
A long-standing uncertainty has existed as to the number of water molecules in the primary coordination environment of the OH(-) and F(-) ions in aqueous chemistry. We report the vibrational spectra of the OH(-).(H2O)n and F(-).(H2O)n clusters and interpret the pattern of OH stretching fundamentals with ab initio calculations. The spectra of the cold complexes are obtained by first attaching weakly bound argon atoms to the clusters and then monitoring the photoinduced evaporation of these atoms when an infrared laser is tuned to a vibrational resonance. The small clusters (n </= 3) display an isolated, sharp feature near the free OH stretching vibration, the signature of open solvation morphologies where each water molecule binds independently to the ion. Dramatic changes in the spectra are observed at n = 4 in the hydroxide ion and at n = 5 in the fluoride ion. In both cases, new features appear in the region typically associated with interwater hydrogen bonding. This behavior establishes that the primary hydration shells occur at n =3 and 4 in hydroxide and fluoride, respectively.
PMID: 12543981 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12620863&dopt=Abstract
Appl Environ Microbiol 2003 Mar;69(3):1710-20Role of Rhodobacter sp. Strain PS9, a Purple Non-Sulfur Photosynthetic Bacterium Isolated from an Anaerobic Swine Waste Lagoon, in Odor Remediation.
Do YS, Schmidt TM, Zahn JA, Boyd ES, De La Mora A, DiSpirito AA.
Departments of Microbiology. Psychology, Iowa State University, Ames, Iowa 50011. Department of Microbiology and Molecular Genetics and Center for Microbial Ecology, Michigan State University, East Lansing, Michigan 48824.
Temporal pigmentation changes resulting from the development of a purple color in anaerobic swine waste lagoons were investigated during a 4-year period. The major purple photosynthetic bacterium responsible for these color changes and the corresponding reductions in odor was isolated from nine photosynthetic lagoons. By using morphological, physiological, and phylogenetic characterization methods we identified the predominant photosynthetic bacterium as a new strain of Rhodobacter, designated Rhodobacter sp. strain PS9. Rhodobacter sp. strain PS9 is capable of photoorganotrophic growth on a variety of organic compounds, including all of the characteristic volatile organic compounds (VOC) responsible for the odor associated with swine production facilities (J. A. Zahn, A. A. DiSpirito, Y. S. Do, B. E. Brooks, E. E. Copper, and J. L. Hatfield, J. Environ. Qual. 30:624-634, 2001). The seasonal variations in airborne VOC emitted from waste lagoons showed that there was a 80 to 93% decrease in the concentration of VOC during a photosynthetic bloom. During the height of a bloom, the Rhodobacter sp. strain PS9 population accounted for 10% of the total community and up to 27% of the eubacterial community based on 16S ribosomal DNA signals. Additional observations based on seasonal variations in meteorological, biological, and chemical parameters suggested that the photosynthetic blooms of Rhodobacter sp. strain PS9 were correlated with lagoon water temperature and with the concentrations of sulfate and phosphate. In addition, the photosynthetic blooms of Rhodobacter sp. strain PS9 were inversely correlated with the concentrations of protein and fluoride.
PMID: 12620863 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12641435&dopt=AbstractChem Res Toxicol 2003 Mar 17;16(3):350-356
Major Intermediates in Organophosphate Synthesis (PCl(3), POCl(3), PSCl(3), and Their Diethyl Esters) Are Anticholinesterase Agents Directly or on Activation.
Segall Y, Quistad GB, Sparks SE, Casida JE.
Environmental Chemistry and Toxicology Laboratory, Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720-3112.
Three phosphotrichlorides [phosphorus trichloride (PCl(3)), phosphorus oxychloride (POCl(3)), and thiophosphoryl chloride (PSCl(3))] with an annual U.S. production of >500 000 000 pounds and their diethyl esters are intermediates in the production of organophosphorus pesticides, plastics, flame retardants, and hydraulic fluids. They are classified as highly toxic to mammals based on acute oral and inhalation data with rats. This study considers their mechanisms of toxicity. PCl(3) and POCl(3) inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) from several species with in vitro IC(50) values of 5-36 and 88-1200 &mgr;M, respectively; PSCl(3) is a less potent inhibitor. These phosphotrichlorides have high vapor toxicity to houseflies with in vivo inhibition of brain AChE activity correlating with mortality. PCl(3) and POCl(3) produce cholinergic poisoning signs on ip administration to mice, and all three phosphotrichlorides give marked in vivo inhibition of serum BChE but not brain AChE activity. PCl(3) is a direct acting AChE inhibitor. Our earlier proposed activation of POCl(3) is confirmed here by preparing pure Cl(2)P(O)OH and its potassium and dicyclohexylamine salts that reproduce the action of POCl(3) as in vitro AChE inhibitors and toxicants in mice. PSCl(3) on hydrolysis yields Cl(2)P(O)SH [which oxidizes with peracid to Cl(2)P(O)SOH] as the proposed activation product. Vapors of (EtO)(2)PCl, (EtO)(2)P(O)Cl, and (EtO)(2)P(S)Cl are lethal to houseflies as in vivo AChE inhibitors, the first two acting directly and the last one on oxidative activation to (EtO)(2)P(O)Cl (possibly by P450) or (EtO)(2)P(O)SCl (a phosphorylating agent in a peracid oxidation system). Thus PCl(3), (EtO)(2)PCl, and (EtO)(2)P(O)Cl act directly as AChE inhibitors whereas POCl(3) and PSCl(3) undergo hydrolytic activation and (EtO)(2)P(S)Cl undergoes oxidative activation. In contrast, the toxicity to mice of phosphofluorides [FP(O)Cl(2), F(Cl)P(O)OH, and F(2)P(O)OH; studied as model compounds for comparison] may be due to liberating fluoride ion.
PMID: 12641435 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12636128&dopt=AbstractJ Am Dent Assoc 2003 Feb;134(2):226-7
Tap water filters.
Moen PureTouch filters remove impurities from tap water without removing fluoride. These carbon block filters consist of finely powdered activated carbon that is combined with a plastic binder material and heated to form a hollow cylinder. The blocks are further wrapped with material to improve performance and reduce clogging. The filters are available with different filtering capabilities (Table 1). The filters mount in the faucet spout or under the sink.
PMID: 12636128 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12772726&dopt=AbstractEye Contact Lens 2003 Jan;29(1 Suppl):S30-2; discussion S57-9, S192-4
Continuous wear contact lens surface chemistry and wearability.
Nicolson PC.
Austin Allen Associates, Inc., Atlanta, GA 30350-4733, USA. paul.nicolson@mindspring.com
Continuous wear (CW) contact lenses are defined as lenses composed of hydrogel polymers containing elements other than carbon, hydrogen, oxygen, and nitrogen that enhance oxygen permeability to an extent greater than water alone. Those elements are silicon and fluorine. Silicon is incorporated as siloxanes, and fluorine is used as fluoroalkyl. Despite the water present in CW lenses, they are not wearable without surface modification because of the tendency of siloxanes and fluoroakyls to move in the soft polymers, orient, and become enriched at the surface. Various methods of surface modification are discussed, with emphasis on the plasma technologies used by the two commercial CW lens products, Focus Night & Day and PureVision. Speculation about future directions in surface chemistry are also presented.
PMID: 12772726 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12769362&dopt=AbstractAnal Sci. 2003 May;19(5):671-3.
Rapid method for the determination of trace fluoride and activation of ion-selective electrode.
Shi SX, Zhu ZG, Suo R, Wang C.
College of Chemistry and Environmental Science, University of Hebei, Baoding 071002, China. ransuo@yahoo.com.cn
A method for activating ISE is proposed that can allow determination of the fluoride concentration at ng mL(-1) level with good precision and accuracy. Fluoride ISE is activated in 0.5 mol L(-1) HClO4 medium and then fluoride is determined in the same medium. The linear range for the determination of fluoride is between 1.00 x 10(-2)-1.00 x 10(-7) mol L(-1), and the detection limit of the method is 1.0 ng mL(-1). The advantage of this method is that it is free from the use of TISAB solution while being, time-saving and labor-saving. A mechanism study of the activation of FISE in HClO4 medium is explained. The method has been used for the determination of trace fluoride in milk and flour with satisfactory results.
PMID: 12769362 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12767180&dopt=AbstractInorg Chem. 2003 Jun 2;42(11):3445-53.
Highly Sensitive Luminescent Metal-Complex Receptors for Anions through Charge-Assisted Amide Hydrogen Bonding.
Sun SS, Lees AJ, Zavalij PY.
Institute for Materials Research and Department of Chemistry, State University of New York at Binghamton, Binghamton, New York 13902-6000.
Two structurally simple and easily synthesized luminescent anion receptors featured with an amide-type anion binding site and rhenium(I) tricarbonyl pyridine signaling units have been developed, and they display outstanding sensitivity and selectivity toward a variety of anionic species. These complexes are highly emissive in solution. Upon anion binding, the emission intensity was significantly quenched. The sensitivities of these complexes are so high that the emission intensity can be effectively quenched by as much as 10% even in the presence of only 10(-)(8) M cyanide or fluoride anions. The ability of formation of intramolecular hydrogen bonding between the amide protons and central pyridine is believed to be responsible for the observed high selectivity.
PMID: 12767180 [PubMed - in process]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12732052&dopt=AbstractPhys Rev Lett. 2003 Apr 18;90(15):155901. Epub 2003 Apr 17.
Fluorine in silicon: diffusion, trapping, and precipitation.
Pi XD, Burrows CP, Coleman PG.
Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom.
The effect of vacancies on the behavior of F in crystalline Si has been elucidated experimentally for the first time. With positron annihilation spectroscopy and secondary ion mass spectroscopy, we find that F retards recombination between vacancies (V) and interstitials (I) because V and I trap F to form complexes. F diffuses in the V-rich region via a vacancy mechanism with an activation energy of 2.12+/-0.08 eV. After a long annealing time at 700 degrees C, F precipitates have been observed by cross-section transmission electron microscopy which are developed from the V-type defects around the implantation range and the I-type defects at the end of range.
PMID: 12732052 [PubMed]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12794884&dopt=AbstractChemistry. 2003 Jun 6;9(11):2396-403.
Unprecedented living olefin polymerization derived from an attractive interaction between a ligand and a growing polymer chain.
Mitani M, Nakano T, Fujita T.
R&D Center, Mitsui Chemicals, Inc. 580-32 Nagaura, Sodegaura, Chiba 299-0265, Japan.
Ti complexes incorporating fluorine-containing phenoxy-imine chelate ligands (fluorinated Ti-FI catalysts) have been demonstrated to induce an unprecedented living polymerization effect with both ethylene and propylene, through an attractive interaction between the fluorine atom in the ligand and a beta-hydrogen atom on the growing polymer chain. With the aid of this attractive interaction, highly controlled living ethylene polymerization, highly-syndiospecific living propylene polymerization, the synthesis of unique block copolymers from ethylene and propylene, and the catalytic production of monodisperse polyethylene and Zn-terminated polyethylene have been realized. The attractive interaction provides a conceptually new strategy for the achievement of controlled living olefin polymerization.
PMID: 12794884 [PubMed - in process]
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