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Fluoride 1993; 26(4):278-281August 17, 1993, press release issued by National Research Council
(National Academy of Science, National Academy of Engineering, Institute of Medicine, Washington, DC, USA.)Health effects of ingested fluoride
Wagner BM, Burt BA, Cantor KP, Krewski D, Levy SM, Eugene E, McConnell EE, Whitford GM
Report available from Office of News and Public Information, 2101 Constitution Avenue NW, Washington DC. Cost: US $35 plus $4 shipping
Two responses to this Press Release:
August 18, 1993, press release issued by William Hirzy, EPA scientist, on behalf of EPA scientists, lawyers and other professionals.
Comments on release of above report
William Hirzy
President, National Federation of Federal Employees, Local 2050. Telephone: 202-260-2383
The union representing EPA professionals has had an interest in EPA's rulemaking activities regarding fluoride since 1985. At that time, a scientist came to the Union complaining that he was forced to write things he did not believe were ethical in order to keep his job.
Since that time the Union has fought against the institutional distortions of science that have characterized the federal government's actions on hazards associated with exposure to fluoride ion. The report issued yesterday by the National Academy of Sciences [NAS], Health Effects of Ingested Fluoride, does little to change the Union's opinion about the improper use of science in this matter.
The failure of NAS to include on the assessment group such active researchers in the field as Drs AK Susheela, John Lee, John Colquhoun, Mark Diesendorf and Edward Czerwinski, in favor of a long list of National Institute of Dental Research grantees, makes the NAS/NRC report suspect from the outset. NIDR is a major promoter of water fluoridation in the government.
Since NAS refused to give me a copy of the report yesterday, I am unable to comment on it in detail at the moment. However, based on the oral summary of it given to NAS to the Drinking Water Committee of ESP's Science Advisory Board [SAB] and the press release that accompanied the report, I can draw some conclusions about it.
First the fear I expressed last April to the SAB - during a NAS progress report on its assessment - that the assessment would not be objective, seems to have been well founded. During the April meeting of the EPA's Science Advisory Board I expressed concern that the cycle of producing only politically acceptable science on fluoride was continuing. That seems to have been just what happened.
One small, but significant example, discernable even without having had a chance to read the entire document, is how the press release and oral presentation yesterday used media spin control to deal with the issue of dental fluorosis. (Dental fluorosis is a condition in which teeth become progressively more damaged, beginning with slight mottling of the enamel and progressing to staining, pitting, cracking and breaking of the tooth.)
Yesterday, NAS stated that the EPA standard of 4 ppm was "appropriate" and would probably result in a small fraction of the population incurring the more severe forms of dental fluorosis. NAS spokesmen and the press release stated that the question of whether dental fluorosis is an adverse health effect, "is one for the regulatory agencies to decide", implying -for media consumption- that no conclusions had been reached on this issue, and that it wasn't very important. But in a May 1992 meeting of the NAS assessment committee which I attended, the members stated a consensus that severe dental fluorosis (the staining, pitting, and cracking stage) is an adverse health effect. I asked the NAS representative after their presentation yesterday what had changed to alter their consensus of May, 1992, and I was told by Committee Chairman Dr Bernard Wagner, that it hadn't changed at all! Dr Wagner then showed me, buried deep in the report, an equivocal statement to the effect that dental fluorosis severe enough to affect food choices, etc. was a real problem.
In this way, the NAS Committee keeps its backside covered with some allusion to the adverse nature of an effect expected to occur in some people at the "appropriate" level of fluoride in drinking water.
This logical and ethical conundrum appears to have caused little problem for the NAS Committee. It probably will cause very large problems for the maintenance of the "appropriate" 4 ppm standard by EPA. The Safe Drinking Water Act requires EPA to set enforceable standards that protect against adverse health effect with an adequate margin of safety. If NAS expects the 4 ppm standard to result in induction of severe dental fluorois in some people, then the standard must be abandoned.
This one example points out -and I am sure that after studying the report in detail others will surface- why EPA chose to once again contract out the job of assessing fluoride risks, rather than give the job to sworn-to-duty Civil Service scientists. An honest assessment of risks might lead to publicity that could damage the Public Health Service's long-standing program of trying to convince Americans to fluoridate all public water supplies.
This situation exacerbates the sense of frustration among EPA scientists, who are offended by the Agency's buying science, which implies that EPA employees are unworthy of performing such an important piece of work.
Press release issued August 19, 1993, by Robert Carton, former EPA scientist, now Editor of The Fluoride Report
The Fluoride Report, PO Box 219, Buckeystown MD 21717, USA
The "Clean Bill of Health" Report on fluoride, released by a selected Panel of the National Research Council of the National Academy of Sciences (NAS) on August 17, proclaiming fluoride in drinking water to be safe and not linked to cancer, diseases and other ill effects, is propaganda masquerading as science. The NAS undermined it own claims of safety of the current EPA standard by admitting to shocking new evidence that fluoride causes bone fractures in the elderly and bone cancer in young males, that severe dental fluorosis is on the rise in young children, and by admitting that they are completely baffled about how much fluoride people are exposed to from all sources: their diet, mouthrinses, tooth paste, etc. Instead of calling for an immediate end to the practice of fluoridation and more reserch, the National Reserch Council recommends continuing the massive human experiment of fluoridation, while conducting research to see if the practice is causing harm. This recommendation amounts to human experimentation without informed consent, and should be condemned.
The EPA, which has jurisdiction over fluoride in drinking water, was required by law to review the levels of fluoride allowed in public water supplies three years after its drastic raising of the maximum contaminant level of fluoride in 1985 [to 4 ppm]. Instead, they have been delaying their investigation and delegating their duties to others. Money was given to NAS to conduct a review of the latest fluoride studies and give their recommendtion to EPA. Fluoridation critics questioned from the beginning the validity of the outcome, based on the biased panel that NAS formed. Many of the panel members have received grant money from the National Institute of Dental Research, and none of the scientists who are concerned about fluoride's health effects were permitted on the panel. NAS and NRC are included on lists of endorsements of fluoridation for many years, while purporting to be "independent entities."
Fluoride 1993; 26(2):83-96Fluoridation and cancer
The biology and epidemiology of bone and oral cancer related to fluoridationJA Yiamouyiannis
Safe Water Foundation, 6439 Taggart Road, Delaware, Ohio 43015
Summary: Recent studies showing substantial increases in the incidence of bone cancer and osteosarcoma in males (but not females) exposed to fluoride gave us the unique opportunity of using females as a control group to determine whether there is a link between fluoridation and bone cancer in males. Using three different data bases, we found that
1) the bone cancer incidence rate was as much as 0.95 cases a year per 100,000 population higher in males under age 20 living in fluoridated areas;
2) the osteosarcoma incidence rate was 0.85 new cases a year per 100,000 population higher in males under age 20 living in fluoridated areas; and
3) for males of all ages, the bone cancer death rate and bone cancer incidence rate was as much as 0.23 and 0.44 cases higher per 100,000 population, respectively, in fluoridated areas.These indings indicate that fluoridation is linked to an increase in bone cancer and deaths from bone cancer in human populations among males under age 20 and that this increase in bone cancer is probably all due to an increase in osteosarcoma caused by fluoride. Results indicating a fluoridation-linked 30-60% increase in oral cancers are also presented.
Fluoride 1993; 26(2):97-104Prevalence of endemic fluorosis with gastrointestinal manifestations in people living in some north-Indian villages.
Susheela AK, Kumar A, Bhatnagar M, Bahadur R
Fluoride and Fluorosis Research Laboratories, Department of Anatomy, All India Institute of Medical Sciences, New Delhi 110 029, India. Correspondence to Professor AK Susheela.
Excerpt from Summary: ... It is concluded that in an endemic zone, where the inhabitants are consuming water of high fluoride content, the ocurrence of gastrointestinal complaints - viz., loss of appetite, nausea, abdominal pain, flatulence, constipation and intermittant diarrhoea - is one of the early warning signs of fluoride toxicity and fluorosis. When water with neglible amounts of fluoride (safe water) is provided, the complaints disappear within a fortnight.
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8325259&dopt=AbstractEnviron Res 1993 Jul;62(1):14-8
Effect of long-term administration of sodium fluoride on plasma calcium level in relation to intestinal absorption and urinary excretion in rabbits.
Das TK, Susheela AK.
Department of Anatomy, All India Institute of Medical Sciences, New Delhi.
The present study was undertaken to determine the effect of chronic fluoride toxicity on calcium metabolism. Rabbits (n = 10) were orally administered an aqueous solution of 10 mg NaF/kg body wt daily for 18 months. Equal numbers (n = 10) of age-, sex- and weight-matched rabbits kept under identical laboratory conditions, but not treated, with NaF solution, served as control. The fasting plasma calcium concentrations of fluoride-treated rabbits were significantly lower (P < 0.001) than those of control animals. In contrast to the decrease in plasma calcium level, and increase in intestinal radioactive calcium (45Ca) absorption was observed (P < 0.001) in all fluoride-treated animals. However, urinary calcium excretion levels were found to be reduced (P = not significant) in fluoride-treated rabbits. It is therefore concluded that long-term fluoride poisoning alters the calcium homeostatic mechanism, thereby affecting calcium metabolism.
PMID: 8325259 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8236309&dopt=AbstractStomatologiia (Mosk) 1993 Jul-Sep;72(3):61-4
[The status of the teeth and periodontal tissues of children living in an area polluted by the wastes from an aluminum plant]
[Article in Russian]
Zhumatov UZh.
The author compares dental, periodontal, and bone system status of children living in two regions characterized by different degrees and patterns of environmental pollution. Children living in regions polluted by aluminum plant waste (sulfur dioxide, nitrogen dioxide, carbon monoxide, dust, hydrogen fluoride) developed specific abnormalities because of body poisoning with fluorides, namely, dental fluorosis, osteoporosis and osteosclerosis of the bones; periodontal diseases in these children were more incident than in controls. These findings prompted the development of a complex of sanitary, technologic, health, therapeutic and prophylactic measures aimed at reduction of fluorine levels in the environment to the normal level and of dental diseases incidence among children living near the Tajik aluminum plant.
PMID: 8236309 [PubMed - indexed for MEDLINE]
Fluoride 1993; 26(2):105-110Effect of dietary fluorine on histopathological changes in calves
Kapoor V (1), Prasad T (2), Bhatia KC (3)
(1) Department of Animal Nutrition, Haryana Agricultural University, Hisar 125 004, India.
(2) Department of Dairy Cattle Nutrition, National Dairy Research Institute, Karnal, India.
(3) Department of Veterinary Pathology, Haryana Agricultural University, Hisar, India.Summary: To investigate the pathological effects of subclinical levels of dietary fluorine (F) on twenty male Karan Fries calves about 6-8 months, the experimental calves were given diets comprised of concentrate mixture and green maize (50:50 for first 3 months and 40:60 during the later phase). For the preparation of mineral mixture (incorporated in the concentrate mixture), two sources of phosphorus supplements, viz., dicalcium phosphate and rock phosphate, either as such or fortified with sodium fluoride, were used. The resultant dietary F levels in the four groups were 7, 79, 132, and 191 ppm. The liver and kidney showed mild degenerative and inflammatory changes. Bone exhibited periosteal hyperostosis, compactness of bony tissues and osteopetrotic changes, indicating initial alterations in bony tissues resulting from pre-clinical conditions of dietary F excess.
Fluoride 1993; 26(2):111-114Plasma fluoride levels in preterm babies
Satar M, Savas N, Altinbasak S, Boztepe H
Division of Neonatology, Department of Pediatrics, Faculty of Medicine, Cukurova University, Balcali-01330, Adana-Turkey. Address correspondence to Dr. Mehmet Satar.
Summary: Plasma fluoride levels were determined in 25 term and 32 preterm babies. Venous blood samples were obtained within the first 48 hours of life and analyzed by the fluoride-ion selective electrode. Mean plasma fluoride levels +- 8.40 mg/L vs 57.74 +- 6.94 mg/L, p <0.001>. Plasma fluoride levels showed no correlation with gestational age and birth weight, respetively (r = 0.33, p >0.05; r = 0.30, p >005).
Fluoride 1993; 26(2):115-124Fluoride concentrations in dentine and acid-induced demineralization in vitro
DYD Samarawickrama (1) and RL Speirs (2)
(1) Department of Conservative Dentistry, The London Hospital Medical College, Turney Street, London, England.
(2) Royal College of Surgeons of England, Lincoln's Inn Fields, London, England. Correspondence to Dr Samarawickrama.
Fluoride 1993; 26(2):125-134Fluorides and the decline of tooth decay in New Zealand
J Colquhoun
Formerly Principal Dental Officer, Department of Health, Auckland, New Zealand. Now Honorary Research Fellow, Education Department, University of Auckland.
Summary: National data collected in New Zealand over a 50-year period indicate the decline in tooth decay in that country commenced before and independently of the introduction of fluoridation and other uses of fluoride. The start in 1977 of a reported steep decline in permanent tooth decay, measured by counting the number of tooth restorations inserted into children's mouths, coincided with a change in diagnostic criteria for provision of such restorations within the School Dental Service, in which 98% of the nation's children are enrolled for treatment. The recent decline in permanent tooth decay has been slightly steeper in nonfluoridated areas. Some professional responses to these data are described and discussed.
Fluoride 1993; 26(2):135-139Book Review
Scientific knowledge in controversy
The social dynamic of the fluoridation debateState University of New York Press, Albany NY. 1991.
By Brian Martin
Reviewed by FI Scott Jr
Mr. Scott, BE (John Hopkins University), MS (Newark College of Engineering), a chemical engineer by training, is editor of American Clinical Laboratory and consulting editor for other publiations (American Laboratory, American Biotechnology Laboratory and American Environmental Laboratory) of International Scientific Communications, Inc.
Excerpt: Brian Martin has written a remarkably comprehensive account of the history and dynamics of the controversy surrounding the addition of fluoride-containing salts (artificial fluoridation) to community drinking water for uncontrolled consumption by the public... It should b3e required and desired reading for anyone interested in science and scientific research, particularly in regard to public policy, and for educators seeking insights toward the goal of achieving science literacy among scientists-to-be and nonscientists-to-be...
Fluoride 1993; 26(4):237-239Guest Editorial: Another look at the interactions of fluorine with calcium
A Machoy-Mokrzynska and Z Machoy
Pomeranian Medical Academy, Szczecin, Poland
Fluoride 1993; 26(4):241-246Plasma biochemistry of adult goats with chronic fluoride poisoning in Morocco
Bennis A (1), Kessabi (2), Hamliri (2), de LaFarge F (3), Braun JP (1)
(1) Department of Physiopathology, Ecole Nationale Veterinaire, Toulouse, France.
(2) Department of Pharmacy-Toxicology, Institut Agronomique et Veterinaire Hasan II, Rabat, Morocco.
(3) Department of Biochemistry, Rangueil Hospital, Toulouse, France. Correspondence to Professor JP Braun.Summary: Biochemical screening of goat plasma of the Darmous zone of Morocco where fluorosis is endemic showed mainly increases of potassium, phosphates, urea, bilirubin and GGT, while decreases of glucose, cholesterol, phospholipids, total proteins and y-globulins were observed. These changes are similar but less intense than those previously reported in cattle or sheep.
Fluoride 1993; 26(4):247-256The excretion of urinary glycosaminoglycans by fluorotic rats
JB Stanbury (1) and G Embery (2)
(1) Department of Clinical Dental Science, University of Liverpool, England.
(2) Department of Basic Dental Science, Dental School, University of Wales, College of Medicine, Cardiff, WalesSummary: This study describes differences in excretion of sulphated glycoproteins, including glycosaminoglycans and possibly Tam-Horsfall like proteins, in the urine of fluorotic and control rats. Changes in molecular size of protein and covalently bound radiosulphate profiles together with differences in Alcian blue and Poneau S staining of the electrophoreticaly separated molecular size fractions were evident in fluorotic urines. The findings highlight changes in connective tissue in fluorosis which manifest themselves as urinary metabolites.
Excerpt: Glycosaminoglycans (GAG) are high molecular weight linear heteropolysaccharides which are covalently linked to a specific core protein to form proteoglycans (PG). These in turn interact with collagen and in mineralised tissues are arranged in such a manner to function as templates for the deposition of calcium phosphate crystals during mineralisation of dentine and bone...
Fluoride 1993; 26(4):257-262Factors of individual predisposition to occupational fluorosis
Polzik EV, Valova GA, Shcberbakov SV, Yakusheva MY
Ecological Safety Center, Ural Division of the Russian Academy of Sciences, Ekaterinburg, Russia
Summary: Fourteen different risk factors for occupational fluorosis were studied comprehensively among workers engaged in cryolite production. For multifactorial analysis use was made of mathematical methods of pattern recognition. The results of recognition of the "exam" samples are as follows: the group of workers who did not fall ill with fluorosis - 81.4%; the group of workers who fell ill with fluorosis - 66.6%. Each factor was estimated for its degree and direction of influence. For estimating genetic predisposition to fluorosis dermatoglyphics were used as markers. The elimination of the effect of basic non-genetic risk factors and comdprehensive analysis using the pattern recognition methods show that genetic predisposition to fluorosis does exist.
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8088573&dopt=AbstractGig Sanit 1993 Apr;(4):22-5
[Risk factors of fluorosis in workers of aluminum and cryolite plants]
[Article in Russian]
Valova GA, Polzik EV, Shcherbakov SV, Gureva OL.
PMID: 8088573 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8133932&dopt=AbstractNephrol News Issues 1993 Sep;7(9):32-6
- Understanding the dangers of fluoride during dialysis.
Wathen RL, Burcham CW Jr.
PMID: 8133932 [PubMed - indexed for MEDLINE]
- http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8354112&dopt=Abstract
Zhonghua Yu Fang Yi Xue Za Zhi 1993 Mar;27(2):88-90
[Study on determinationing the bone mineral content as diagnostic value for occupational fluorosis]
[Article in Chinese]
Wei XY.
Institute of Labor Health of Baiyin, Nonferrous Metals Company, Gansu.
The results of determination of the bone density of 194 workers exposed to fluorine by SPA-III type osteodensimeter were compared with people unexposed to fluorine, and with the results of diagnosing the luorosis by X-ray.
(1) The abnormal bone cortex thickness and density rate in the people exposed to fluorine was significantly higher than the ordinary people (P < 0.05).
(2) In the people exposed to fluorine, the correspondency rate of determining fluorosis of bone by X-ray and by osteodensimeter were 84.6%, and results of the two methods had no significant difference (P > 0.05).
(3) In another group of 155 cases, whose values of hair fluorine and urinary fluorine were higher than the ordinary people (66.5%), the abnormal density of bone of 103 cases had been determined by osteodensimeter, but not by X-ray. This showed that the diagnosis of early changes of osteofluorosis by osteodensimeter was more sensitive than by X-ray.
(4) There was close association between the unusual rate of osteodensity and the superstandard rate of hair fluorine and urinary fluorine.
The above findings indicated the determination of bone density can be used as a diagnostic index for occupational fluorosis.
PMID: 8354112 [PubMed - indexed for MEDLINE]
Fluoride 1993; 26(4):263-266WHO data on dental caries and natural water fluoride levels
R Ziebelbecker (1) and RC Ziegelbecker (2)
(1) Peterstalstrasse, Graz, Austria
(2) Franckstrasse, Graz, AustriaSummary: Data collected in 1987 from World Health Organization data banks contradict earlier reports of an inverse relationship between dental caries prevalence and drinking water fluoride levels.
Fluoride 1993; 26(4):267-273Allergy and hypersensitivity to fluoride
Bruce Spittle
Department of Psychological Medicine, School of Medicine, University of Otago, PO Box 913, Dunedin, New Zealand
Summary: A review of the literature was undertaken in response to four recent reviews which found the evidence that fluoride was an allergen was unconvincing. Reports were found of urticaria, contact dermatitis and stomatitis occuring in response to fluoride, settling on the withdrawal of fluoride and recurring with appropriate challenges. It is concluded that the four reviews were seriously incomplete in their coverage of the literature, and that when a more complete examination is made there are reasonable grounds for concluding that there are individuals in whom allergy or hypersensitivity to fluoride has been demonstrated. The sources of fluoride included those used in the fluoridation of community water supplies.
Fluoride 1993; 26(4):274-277Fluoridation and hip fracture. According to the National Research Council Report: "Health Effects of Ingested Fluoride"
JR Lee
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8244868&dopt=AbstractJ Am Vet Med Assoc 1993 Oct 15;203(8):1176-7
Accidental superphosphate fertilizer poisoning in pregnant ewes.
East NE.
Department of Medicine, School of Veterinary Medicine, University of California, Davis 95616.
Consumption of superphosphate fertilizer by 200 pregnant ewes resulted in signs of toxicosis in 41 ewes, 14 of which died. Predominant clinical signs were marked teeth grinding, voluminous diarrhea, CNS depression, apparent blindness, and a stiff-legged atactic gait. Biochemical abnormalities were hypocalcemia, hypoglycemia, and a high anion gap. The primary toxic principal in superphosphate fertilizers is the fluorine contaminant; however, calcium pyrophosphate and calcium orthophosphate also contribute to toxicosis, which results in acute proximal renal tubular necrosis. Voluntary consumption of superphosphate fertilizer in well-fed livestock is not expected, and was believed to be related to the lack of availability of salt.
PMID: 8244868 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8405753&dopt=AbstractDiabetologia 1993 Sep;36(9):826-8
Reversible impairment of glucose tolerance in patients with endemic fluorosis. Fluoride Collaborative Study Group.
Trivedi N, Mithal A, Gupta SK, Godbole MM.
Department of Medical Endocrinology, Sanjay Gandhi Post-Graduate Institute of Medical Sciences, Lucknow, India.
Endemic fluorosis is a condition resulting from prolonged ingestion of drinking water which contains excess fluoride. Studies on rats have suggested that fluoride toxicity may produce glucose intolerance and abnormalities in insulin secretion. We studied glucose and insulin profiles following an oral glucose load in patients with endemic fluorosis. Twenty-five young adults (age range, 15-30 years) with endemic fluorosis, and an equal number of matched healthy control subjects with normal fluoride intake were studied. Impaired glucose tolerance was demonstrated in 10 of 25 (40%) patients with endemic fluorosis. Patients with impaired glucose tolerance had significantly higher fasting serum immunoreactive insulin (p < 0.05), higher fasting serum fluoride (p < 0.001), and a significantly lower fasting glucose to insulin ratio than that in patients with normal glucose tolerance (p < 0.001) or control subjects (p < 0.05). The fasting serum fluoride levels correlated positively with the area under the glucose curve (r = 0.80, p < 0.01) in patients with impaired glucose tolerance. Interestingly these abnormalities could be reversed when the village was provided drinking water with fluoride levels within acceptable limits. The present study shows that chronic fluoride toxicity in humans could result in significant abnormalities in glucose tolerance which are reversible upon removal of the excess fluoride.
PMID: 8405753 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8155406&dopt=AbstractBone 1993 Nov-Dec;14(6):835-41
Distribution profiles of fluoride in three different kinds of rat bones.
Li J, Nakagaki H, Kato K, Ishiguro K, Ohno N, Kameyama Y, Mukai M, Ikeda M, Weatherell J, Robinson C.
Department of Preventive Dentistry and Dental Public Health, School of Dentistry, University of Leeds, Clarendon Way, UK.
The study was performed to reveal the detailed distribution profiles of fluoride in three different kinds of rat bone--humerus, vertebral arch, and parietal bone--and to compare this with the histological appearance of each bone type. Two groups of Wistar rats were provided water ad libitum containing 0 and 100 ppm fluoride, respectively, for 24 weeks. The fluoride distribution profiles across the bone of the three different bones from the outer to the inner surface were determined by means of an abrasive micro-sampling technique. In control animals, both humerus and parietal bones showed higher concentrations at the periosteal and endosteal surfaces, while the vertebral arch showed additional high levels in the middle (containing trabecular bone) of the tissue. In exposed animals, fluoride levels increased greatly in all three bone types. The vertebral and parietal fluoride distribution profiles were relatively unchanged, although humerus fluoride increased from periosteum to endosteum. The differences in fluoride distribution profiles were apparently related to the histological appearances of these bones. The surface area of bone available and the extent of vascularity appear to affect fluoride uptake.
PMID: 8155406 [PubMed - indexed for MEDLINE]
Fluoride 1993; 26(1):23-32Cytogenetic effect of gaseous fluorides on grain crops
NP Gritsan
Institute of Nature Management Problems and Ecology, Ukrainian Academy of Sciences, Moscovskaja 6, Dniepropetrovsk 320600, Ukraine
Summary: Atmospheric pollution of fluoride from a non-ferrous industrial plant has been studied for its effect on the frequency of chromosome aberrations in root tips and shoot tips of wheat and barley. The anaphase-test was used. The percentage of mutations in the meristematic cells of plants growing in polluted areas was 2-6 times higher than in the control and the spectrum of chromosome abberations showed changes. The testing of hydrogen fluoride (HF) for its mutagenic activity by fumigation of barley seedlings showed that the mutation rate was linear with dose. It was found that the cytogenic effects of gaseous fluoride on grain crops was correlated with the fluoride content in plant tissue.
Fluoride 1993; 26(1):33-36Effect of carbon treatment on aqueous fluoride determinations
AW Burgstahler and JS Lockhart
Professor AW Burgstahler, Department of Chemistry, the University of Kansas, Lawrence, Kansas 66045
Summary: Various aqueous samples (e.g., tap water, tea infusions, coffee extracts, fruit and vegetable juices) were stirred with four kinds of laboratory grades of decolorizing carbon and analyzed for fluoride by the ion-selective electrode method. Depending on the nature of the sample and the type of activity of the carbon, small decreases in the fluoride content (generally on the order of 5 to 15 percent, but sometimes considerably more, especially with Norit-A (Alkaline) and Nuchar C-190N), were observed compared to the results without carbon treatment.
Fluoride 1993; 26(1):37-44Bone structure assessment on radiographs of distal radial metaphysis in children with dental fluorosis
D Chlebna-Sokol (1) and E Czerwinski (2)
(1) Institute of Paediatrics, Academy of Medicine, Lodz, Poland
(2) Department of Orthopaedics, Cracow Academy of Medicine, PolandSummary: The effect of fluoride on bone structure was assessed in children with endemic dental fluorosis by use of radiographs of the distal radial metaphysis of test children and those of unfluoridated age-matched controls. Bone structure assessment was based on the computerized image analysis of the radiographs. In addition, the quantitative description of bone structure was analyzed in terms of correlation with age, sex, and serum calcium, magnesium, and alkaline phosphatase levels. Our findings indicate greater trabecular height and area in chiildren with dental fluorosis than in controls. Detailed analysis of the results, in relation to age and gender, showed that the significant differences were between younger age groups and between boys. This finding indicates a stronger influence on children of younger developmental age.
Fluoride 1993; 26(1):61-65An experimental study for early diagnostic features in fluorosis
Wang J, Zheng ZA, Zhang LS, Cao DM, Chen KZ, Lu D
Dr Jei Wang, Hunan Institute of Labour Hygiene and Occupatioal Disease, Changsha, Hunan 410007, China
Summary: Creatine phosphokinase (CPK) activity and fluoride contents in serum, hair and varius bones were determined at different periods in 28 experimental rabbits with subacute fluorosis induced by different orally-fed dosages of sodium fluoride. CPK activity, and fluoride content in serum, hair and bone increased in relation to exposure time or the dose of fluoride. These changes in fluoride content may be valuable for early diagnosis of fluorosis.
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8266827&dopt=AbstractJ Bone Miner Res 1993 Nov;8(11):1357-63
Differential effects of fluoride during initiation and progression of mineralization of osteoid nodules formed in vitro.
Bellows CG, Aubin JE, Heersche JN.
MRC Group in Periodontal Physiology, Faculty of Dentistry, University of Toronto, Ontario, Canada.
Osteoid nodules form in cultures of fetal rat calvarial (RC) cells grown in medium containing 10% FBS and 50 micrograms/ml of ascorbic acid. When 10 mM beta-glycerophosphate (beta-GP) is added, osteoid nodules mineralize in two phases: an initiation phase, which is dependent upon alkaline phosphatase activity for conversion of beta-GP to P(i), and a progression phase that proceeds independently of alkaline phosphatase activity and does not require exogenous phosphate. We have now used this system to investigate the effects of fluoride (F-) on mineralization. In cultures in which osteoid was formed and mineralization initiated in the presence of F-, a dose-dependent inhibition of the initiation of mineralization occurred over a concentration range of 25-500 microM F- (p < 0.001 in all cases). The initiation of mineralization was not inhibited if F- was removed from the cultures at the time when mineralization was initiated with beta-GP. In osteoid nodules grown in the absence of F-, addition of F- resulted in a dose-dependent inhibition of the initiation of mineralization, with significant decreases in 45Ca uptake occurring at F- concentrations of 3 microM (p < 0.01) and higher. However, if F- was added to cultures after mineralization was initiated in the absence of F-, a stimulation of 45Ca uptake was observed at F- concentrations of 250 microM and above (p < 0.001). F- (1-1000 microM) did not affect the conversion of beta-GP to P(i) or alkaline phosphatase activity in the cultures.(ABSTRACT TRUNCATED AT 250 WORDS)
PMID: 8266827 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8304046&dopt=AbstractJ Bone Miner Res 1993 Dec;8(12):1453-8
1,25-dihydroxyvitamin D3 potentiates fluoride-stimulated collagen type I production in cultures of human bone marrow stromal osteoblast-like cells.
Kassem M, Mosekilde L, Eriksen EF.
University Department of Endocrinology and Metabolism, Aarhus amtssygehus, Denmark.
In this study we tested the effects of sodium fluoride (NaF) in serum-free cultures of human marrow stromal osteoblast-like [hMS(OB)] cells. NaF (10(-5) M) stimulated hMS(OB) cell proliferation up to 220% of control cultures. NaF alone did not increase type I collagen production, but in the presence of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] (10(-9) M), NaF enhanced type I collagen production in a dose-dependent way to 300% of 1,25-(OH)2D3-treated control cultures. The production of alkaline phosphatase (ALP) and osteocalcin (bone gla protein, BGP) was also enhanced in the presence of 1,25-(OH)2D3 to 170 and 200%, respectively, of 1,25-(OH)2D3-treated controls. Our results suggest that 1,25-(OH)2D3 potentiates fluoride-mediated anabolism in hMS(OB) cell cultures and suggest that osteoblast precursors in bone marrow are targets for fluoride action.
PMID: 8304046 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8176697&dopt=AbstractJ S Afr Vet Assoc 1993 Dec;64(4):165-8
Two outbreaks of fluorosis in cattle and sheep.
Botha CJ, Naude TW, Minnaar PP, Van Amstel SR, Janse van Rensburg SD.
Department of Pharmacology and Toxicology, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Republic of South Africa.
Two outbreaks of fluorosis in cattle and sheep were investigated in the Northern Transvaal. The animals exhibited severe dental lesions, lameness and exostoses. Plasma fluoride concentrations were high and there was an inversion of the albumin/globulin ratio. Alkaline phosphatase activity was elevated. Drinking water from boreholes contained excessive amounts of fluoride and upon irrigation, pastures were also contaminated with fluoride.
PMID: 8176697 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8141669&dopt=AbstractArch Oral Biol 1993 Dec;38(12):1071-81
Fluoride-induced developmental changes in enamel and dentine of European roe deer (Capreolus capreolus L.) as a result of environmental pollution.
Kierdorf U, Kierdorf H, Fejerskov O.
I. Zoological Institute, University of Gottingen, Germany.
Using macroscopic, microradiographic and scanning electron-microscopic methods, the effects of increased fluoride exposure on enamel and dentine formation were studied in fluorosed mandibular premolars and molars of roe deer from the heavily industrialized Ruhr area, Germany. Macroscopically, fluorosed teeth were characterized by opaque and stained enamel and in more severe cases also by enamel surface lesions, reduction or loss of enamel ridges on their occlusal surfaces and increased wear. Microradiographically, fluorosed enamel exhibited different degrees of subsurface hypomineralization, in part apparently indicating a fluoride effect during enamel maturation. In some specimens, a pronounced but varying enhancement of the pattern of Retzius lines was observed throughout the enamel, denoting strongly intermittent fluoride exposure during enamel matrix secretion. This variation in exposure was also reflected histologically in dentine, by bands of interglobular dentine and marked accentuation of incremental lines. Microradiography of sections through enamel surface hypoplastic lesions showed the enamel forming the bottom and partly also the walls of the lesions to be highly mineralized. Scanning electron microscopy showed that the outer enamel along the more pronounced hypoplastic lesions consisted of stacked, thin layers of 'aprismatic' enamel, indicating that the ameloblasts in these areas had lost the distal (rod-forming) regions of their Tomes' processes. These observations demonstrate that the origin of enamel hypoplasias in deer clearly differs from that in rodents, where fluoride induces the formation of subameloblastic cysts. The differences in the degree of fluorotic alteration between the teeth of a single tooth row could be related to the developmental sequence of the dentition in roe deer. The roe deer is thus considered to be a very sensitive and useful bioindicator of environmental pollution by fluorides.
PMID: 8141669 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8141664&dopt=AbstractArch Oral Biol 1993 Dec;38(12):1031-44
Enameloid formation in two tetraodontiform fish species with high and low fluoride contents in enameloid.
Prostak KS, Seifert P, Skobe Z.
Forsyth Dental Center, Boston, MA 02115.
Forming teeth of parrotfish and pufferfish were viewed by transmission electron microscopy to correlate cytological features of the enameloid organ with the species' fluoride (F) content in mature enameloid. Secretory-stage inner dental epithelial cells (IDE) of parrotfish (high F) and pufferfish (low F) secreted procollagen granules into the enameloid collagen matrix. The odontoblasts of both species, less numerous than IDE cells, also contained procollagen granules at the enameloid matrix formation stage. After the full thickness of enameloid matrix collagen had been deposited, enameloid crystallites formed parallel to the long axis of the enameloid collagen fibres. Concurrently, the plasma membranes of the outer dental epithelial cells (ODE) became invaginated in both species, but to a much greater extent in parrotfish. Highly undulating parrotfish ODE cells surrounded numerous fenestrated capillaries. In contrast, pufferfish ODE cells remained straight with few adjacent capillaries. Extensive tight junctions formed between ODE and IDE cells of both species, sealing the extracellular space. With increased mineralization, enameloid collagen fibres were no longer discernible. A thin layer of amorphous material, which subsequently mineralized, was secreted on to the enameloid surface by IDE cells in both species. Pufferfish odontoblasts secreted a mineralizing amorphous layer on the pulpal aspect of the enameloid. The results suggest that at the mineralization stage, a triad of cytostructural features, highly invaginated ODE cells, highly vascularized ODE cells, and extensive tight junctions are strongly correlated with high fluoride content of mature enameloid mineral. Species without any one of these features have lower fluoride in the enameloid.
PMID: 8141664 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8298577&dopt=AbstractNucl Med Biol 1993 Nov;20(8):973-81
Fluorine-18 and carbon-11 labeled amphetamine analogs--synthesis, distribution, binding characteristics in mice and rats and a PET study in monkey.
Shiue CY, Shiue GG, Rysavy JA, Pleus RC, Huang H, Bai LQ, Cornish KG, Sunderland JJ, Frick MP.
Center for Metabolic Imaging, Creighton University, Omaha, NE 68108.
No-carrier-added (NCA) (+-)-p-[18F]fluoroamphetamine (2a) and (+-)-6-[18F]fluoro-3,4-methylene-dioxy-amphetamine (2b) were synthesized through a multistep synthesis by nucleophilic substitution of the appropriate precursors (p-nitrobenzaldehyde, 1a and 6-nitropiperonal 1b, respectively) with [18F]fluoride followed by condensation with nitroethane and reduction with LAH in 20-30% yield (EOB) in a synthesis time of 90-109 min from EOB. NCA (-)-[11C]methamphetamine (4a) and (+-)-3,4-methylene-dioxy-N-[11C]methamphetamine (4b) were synthesized by methylation of the appropriate desmethyl precursors 3a and 3b with [11C]H3I in 40-60% yield (EOB) in a synthesis time of 30 min from EOB. Animal studies in mouse and rat revealed that the relative tissue uptake of these radiotracers was kidneys > lungs > liver > spleen > brain > heart > blood. The uptakes of these radiotracers in mouse brain were high and similar at 5 min post-injection (approx. 5%/g) but radioactivity then declined rapidly (approx. 1%/g at 60 min post-injection). For compounds 2a and 2b, the activity in the femur did not increase with time indicating in vivo defluorination may not be the major route of metabolism. Monoamine uptake inhibitors (nomifensine, fluoxetine and nisoxetine) did not inhibit but enhance the uptake of (-)-[11C]methamphetamine (4a) in the rat brain by greater than 50%. A PET study in a Rhesus monkey revealed that the uptakes of (-)-[11C]methamphetamine in different brain regions were similar and the retention of the radioactivity in these regions remained constant throughout the study. Analysis of arterial plasma by HPLC showed that 50% of radioactivity remained as 4a at 60 min post-injection.
PMID: 8298577 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8261348&dopt=AbstractCMAJ 1993 Dec 15;149(12):1787-93
- Comment in:
- Can Med Assoc J. 1994 Sep 1;151(5):517
Appropriate uses of fluorides for children: guidelines from the Canadian Workshop on the Evaluation of Current Recommendations Concerning Fluorides.
Clark DC.
Faculty of Dentistry, University of British Columbia, Vancouver.
OBJECTIVE: To prevent fluorosis caused by excessive fluoride ingestion by revising recommendations for fluoride intake by children.
OPTIONS: Limiting fluoride ingestion from fluoridated water, fluoride supplements and fluoride dentifrices.
OUTCOMES: Reduction in the prevalence of dental fluorosis and continued prevention of dental caries.
EVIDENCE: Before the workshop, experts prepared comprehensive literature reviews of fluoride therapies, fluoride ingestion and the prevalence and causes of dental fluorosis. The papers, which were peer-reviewed, revised and circulated to the workshop participants, formed the basis of the workshop discussions.
VALUES: Recommendations to limit fluoride intake were vigorously debated before being adopted as the consensus opinion of the workshop group.
BENEFITS, HARMS AND COSTS: Decrease in the prevalence of dental fluorosis with continuing preventive effects of fluoride use. The only significant cost would be in preparing new, low-concentration fluoride products for distribution.
RECOMMENDATIONS: Fluoride supplementation should be limited to children 3 years of age and older in areas where there is less than 0.3 ppm of fluoride in the water supply. Children in all areas should use only a "pea-sized" amount of fluoride dentifrice no more than twice daily under the supervision of an adult.
VALIDATION: These recommendations are almost identical to changes to recommendations for the use of fluoride supplements recently proposed by a group of European countries.
SPONSORS: The workshop was organized by Dr. D. Christopher Clark, of the University of British Columbia, and Drs. Hardy Limeback and Ralph C. Burgess, of the University of Toronto, and funded by Proctor and Gamble Inc., Toronto, the Medical Research Council of Canada and Health Canada (formerly the Department of National Health and Welfare). The recommendations were formally adopted by the Canadian Dental Association in April 1993.
Publication Types:
- Consensus Development Conference
- Guideline
- Practice Guideline
- Review
PMID: 8261348 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8261353&dopt=AbstractNo Abstract available
CMAJ 1993 Dec 15;149(12):1820-2
Comment in:
- Can Med Assoc J. 1994 Sep 1;151(5):517
MDs call for more study before endorsing dentists' new recommendations on fluoride.
Rafuse J.
PMID: 8261353 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8214701&dopt=AbstractAnesth Analg 1993 Nov;77(5):1018-21
Serum inorganic fluoride levels in mildly obese patients during and after sevoflurane anesthesia.
Higuchi H, Satoh T, Arimura S, Kanno M, Endoh R.
Department of Anesthesiology, National Defense Medical College, Saitama, Japan.
Serum inorganic fluoride levels in obese versus control patients were compared during and after sevoflurane anesthesia. Mean serum inorganic fluoride levels in the obese group increased more rapidly and were significantly higher than in the control group at each sampling time (P < 0.01). The area under the curve of fluoride concentration, versus time up to 24 h and 48 h in the obese patients, was significantly greater than that in the nonobese patients (P < 0.001). Peak serum fluoride level in the obese patients was 51.7 +/- 2.5 mumol/L and exceeded 50 mumol/L for nearly 2 h. Our study showed that serum fluoride concentrations between mildly obese and nonobese patients differed during and after sevoflurane anesthesia.
PMID: 8214701 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8257317&dopt=AbstractAust Vet J 1993 Oct;70(10):379-83
Phosphorus supplements and fluorosis in cattle--a northern Australian experience.
Jubb TF, Annand TE, Main DC, Murphy GM.
Department of Agriculture, Kununurra, Western Australia.
Chronic fluoride toxicosis caused lameness, dental lesions and illthrift in an extensive beef cattle herd in northern Australia. Up to 15% of the herd was lame and the disease forced the culling of large numbers of cows. The source of fluoride was fertiliser-grade monoammonium and diammonium phosphate fed as part of a mineral supplement. Large quantities of mineral supplement were provided to the cattle because lameness was attributed to phosphorus deficiency, which is endemic in the area. Most lameness developed in the late dry season in the post-lactation phase. Severe lameness was caused by fractured pedal bones.
PMID: 8257317 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8271074&dopt=AbstractJ Occup Med 1993 Oct;35(10):1028-33
Lung function in workers refining phosphorus rock to obtain elementary phosphorus.
Dutton CB, Pigeon MJ, Renzi PM, Feustel PJ, Dutton RE, Renzi GD.
Albany Medical College, New York 12208.
Elevated levels of phosphoric acid, phosphorus pentoxide, fluorides and coal tar pitch volatiles were present in workplace air of a two-oven industrial refinery. One hundred thirty-one workers prospectively underwent annual pulmonary function testing (forced vital capacity, forced expiratory volume in 1 second, and forced expiratory flow). Regression of these spirometric data, analyzed longitudinally over 3 to 7 years and also cross-sectionally reveals no residual significant effect of industrial exposure after adjusting for the effect of age and smoking. This industrial exposure contributes only weakly and inconsistently to the well-documented reduction of spirometric lung function that occurs from smoking alone. No significant reductions of spirometry occurred in exposed nonsmokers or former smokers.
PMID: 8271074 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8240404&dopt=AbstractBiochem Pharmacol 1993 Oct 19;46(8):1511-4
Effects of sodium fluoride and cobalt chloride on the enantioselectivity of microsomal and cytosolic esterases in rat intestinal mucosa.
Yang SK, Chang WC, Huang JD.
Department of Pharmacology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799.
The effects of sodium fluoride (NaF) and cobalt chloride (CoCl2) on the enantioselective hydrolysis of racemic oxazepam 3-acetate (rac-OXA) by microsomal and cytosolic esterases in rat intestinal mucosa were studied. Microsomal and cytosolic esterases hydrolyzed S-OXA and R-OXA in approximately 1:19 and 4:1 ratios, respectively. The hydrolysis of R-OXA by microsomal esterases was inhibited by NaF with an IC50 of 13.4 +/- 1.5 mM. Hydrolyses of both S-OXA and R-OXA by cytosolic esterases were inhibited by NaF with a similar IC50 value (approximately 3 mM). The hydrolysis of S-OXA by cytosolic esterases was inhibited by CoCl2 (IC50 = approximately 5 mM), whereas the hydrolysis of R-OXA by cytosolic esterases was stimulated by approximately 10% in the presence of 1 mM CoCl2. In comparison, the hydrolysis of R-OXA by microsomal esterases was stimulated by approximately 55% in the presence of 1 mM CoCl2. These results not only revealed the effects of NaF and CoCl2 on the catalytic activities of enantioselective cytosolic and microsomal esterases, but also indicated that microsomal and cytosolic esterases that selectively hydrolyzed R-OXA were distinctly different protein entities.
PMID: 8240404 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8040692&dopt=AbstractJ Indian Soc Pedod Prev Dent 1993 Mar;11(1):1-3
Placental transfer of fluoride in pregnant women consuming optimum fluoride in drinking water.
Malhotra A, Tewari A, Chawla HS, Gauba K, Dhall K.
Post Graduate Institute of Medical Education and Research, Dept of Dentistry, Chandigarh, India.
The study was conducted on 25 healthy women residing in optimum fluoride areas, who were to deliver normally through vaginal route, to correlate the maternal and cord plasma fluoride levels and evaluate the placental transfer of fluoride. A wide variation was found in the maternal and cord plasma fluoride levels. In only 8 percent of the cases the fluoride levels in cord plasma were higher than maternal plasma. It was deduced that the placenta allows passive diffusion of fluoride from mother to foetus and does not act as a barrier.
PMID: 8040692 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8320609&dopt=AbstractJ Pediatr 1993 Jul;123(1):139-41
Transplacental passage of fluorides.
Gupta S, Seth AK, Gupta A, Gavane AG.
Satellite Hospital, Sethi Colony, India.
Transplacental passage of fluorides was studied in 25 randomly selected neonates. Blood samples collected simultaneously from the mother and the umbilical cord showed that average fluoride concentration in the cord blood was 60% of that in mother's blood. When concentration in the mother's blood exceeded 0.4 ppm, the placenta acted as a selective barrier.
PMID: 8320609 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8357274&dopt=AbstractArch Environ Health 1993 Jul-Aug;48(4):246-9
Air pollution-type fluorosis in the region of Pingxiang, Jiangxi, Peoples' Republic of China.
Chen Y, Lin M, He Z, Xie X, Liu Y, Xiao Y, Zhou J, Fan Y, Xiao X, Xu F.
Jiangxi Institute of Labor Hygiene and Occupational Medicine, Nanchang, Jiangxi, Peoples' Republic of China.
This paper reports on the epidemiology, environmental factors, geological features, and total amount of fluoride intake by residents of the Pingxiang region in the Peoples' Republic of China where there is a high incidence of endemic fluorosis. The results demonstrate that the type of endemic fluorosis is related to air pollution, the major source of which comes from coal that is burned by the residents in their homes. Air pollution also originates from the small kilns that are used to make bricks and tile. The fluorine content in the coal and mud used to mix the coal is considerably high; the content in the mud used as adobe for tiles exceeds 10,000 mg/kg. During the process of burning coal or baking bricks or tiles, a large amount of nonsoluble fluorine is converted into water-soluble fluoride, which can have major human health effects.
PMID: 8357274 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8332951&dopt=AbstractTex Dent J 1993 Feb;110(2):17-20
Fluctuations in tap water fluoride levels: a potential problem for practitioners.
Chan JT, Montgomery EH, Wyborny LE, Starcke EN, Thornby JI.
Departments of Pharmacology & Pediatric Dentistry, University of Texas Health Science Center, Houston.
Weekly water samples were obtained from the tap water at the Dental Branch of the University of Texas Health Science Center at Houston. Analysis of these water samples showed significant fluctuations in fluoride levels from 1988 to 1991. This inconsistency in water fluoride content makes it very difficult for health care providers to prescribe and maintain an optimal fluoride supplementation to children. Based on results from this study, more rigorous surveillance and monitoring of water fluoridation in Houston is recommended.
PMID: 8332951 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8345784&dopt=AbstractMagn Reson Imaging 1993;11(5):697-703
Uptake and life time of fluoride ion in rats by 19F-NMR.
Scarpa M, Vianello F, Rigo A, Viglino P, Bracco F, Battistin L.
Department of Biological Chemistry, University of Padova, Italy.
19F nuclear magnetic resonance (NMR) was utilized to obtain information on the uptake and half-life time of fluoride ion in rats. Changes in tissue fluoride level after acute loading were monitored over time in blood and tissue homogenates obtained from liver and brain. The rate of fluoride elimination from various tissues was roughly similar, following in all cases a first-order kinetic rate law. The F- concentration in brain was about 20% of that found in liver, indicating a reduced fluoride diffusion across the blood-brain barrier. In vivo F- spectra were obtained in rat brain in few minutes with a good signal-to-noise ratio; this confirms the possibility of extending the use of F- as a probe of biomolecules to in vivo applications.
PMID: 8345784 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8229312&dopt=AbstractJ Nutr 1993 Nov;123(11):1939-51
AIN-93 purified diets for laboratory rodents: final report of the American Institute of Nutrition ad hoc writing committee on the reformulation of the AIN-76A rodent diet.
Reeves PG, Nielsen FH, Fahey GC Jr.
United States Department of Agriculture, Grand Forks Human Nutrition Research Center, ND 58202-9034.
For sixteen years, the American Institute of Nutrition Rodent Diets, AIN-76 and AIN-76A, have been used extensively around the world. Because of numerous nutritional and technical problems encountered with the diet during this period, it was revised. Two new formulations were derived: AIN-93G for growth, pregnancy and lactation, and AIN-93M for adult maintenance. Some major differences in the new formulation of AIN-93G compared with AIN-76A are as follows: 7 g soybean oil/100 g diet was substituted for 5 g corn oil/100 g diet to increase the amount of linolenic acid; cornstarch was substituted for sucrose; the amount of phosphorus was reduced to help eliminate the problem of kidney calcification in female rats; L-cystine was substituted for DL-methionine as the amino acid supplement for casein, known to be deficient in the sulfur amino acids; manganese concentration was lowered to one-fifth the amount in the old diet; the amounts of vitamin E, vitamin K and vitamin B-12 were increased; and molybdenum, silicon, fluoride, nickel, boron, lithium and vanadium were added to the mineral mix. For the AIN-93M maintenance diet, the amount of fat was lowered to 40 g/kg diet from 70 g/kg diet, and the amount of casein to 140 g/kg from 200 g/kg in the AIN-93G diet. Because of a better balance of essential nutrients, the AIN-93 diets may prove to be a better choice than AIN-76A for long-term as well as short-term studies with laboratory rodents.
Publication Types: Congresses
PMID: 8229312 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8292746&dopt=AbstractChem Res Toxicol 1993 Sep-Oct;6(5):674-80
Cytochrome P450-mediated oxidation of pentafluorophenol to tetrafluorobenzoquinone as the primary reaction product.
den Besten C, van Bladeren PJ, Duizer E, Vervoort J, Rietjens IM.
Department of Toxicology, Agricultural University, Wageningen, The Netherlands.
In the present study the oxidative dehalogenation of a para-halogenated phenol was studied using pentafluorophenol and its non-para-halogenated analogue 2,3,5,6-tetrafluorophenol as model compounds. 19F NMR was used to characterize the metabolite patterns. In order to study the primary oxidation products of the microsomal cytochrome P450-catalyzed conversion, the alternative oxygen donors cumene hydroperoxide (CumOOH) and iodosobenzene (IOB) were used in addition to the use of NADPH and molecular oxygen. In a NADPH/oxygen-driven reaction, but also in a CumOOH- or IOB-driven cytochrome P450 reaction, tetrafluorophenol was converted to tetrafluorohydroquinone. However, for pentafluorophenol, the formation of tetrafluorohydroquinone as a product of its cytochrome P450-mediated conversion was only observed in the NADPH-driven system. Addition of reducing equivalents such as NADH to the CumOOH or IOB incubations resulted in the formation of tetrafluorohydroquinone. From these data it was concluded that the primary reaction product of the cytochrome P450-catalyzed conversion of pentafluorophenol is a reactive species that can be reduced to tetrafluorohydroquinone by NAD(P)H and, thus, must be tetrafluorobenzoquinone. Additional experiments with tetrafluorobenzoquinone, incubated in vitro with either microsomal protein or glutathione in the presence or absence of reducing equivalents, demonstrated that the tetrafluorobenzoquinone ends up bound to proteins, losing its fluorine atoms as fluoride anions. Thus, while cytochrome P450-mediated conversion of the 2,3,5,6-tetrafluorophenol results in the formation of tetrafluorohydroquinone as the primary reaction product, monooxygenation at a fluorinated para position, such as in pentafluorophenol, results in the formation of the reactive tetrafluorobenzoquinone derivative as the primary reaction product.(ABSTRACT TRUNCATED AT 250 WORDS)
PMID: 8292746 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8242471&dopt=AbstractCalcif Tissue Int 1993 Sep;53(3):187-92
Fluoride increases net 45Ca uptake by SaOS-2 cells: The effect is phosphate dependent.
Farley JR, Hall SL, Herring S, Tanner MA.
Department of Medicine, Loma Linda University, California.
Previous in vitro studies have shown that the effect of fluoride to increase avian osteoblast-like cell proliferation was dependent on the phosphate concentration. In vitro studies have further revealed that fluoride could also have direct effects on osteoblast-like cells to increase phosphate uptake and transiently increase cytosolic calcium. The current studies were intended to determine whether fluoride could increase net 45Ca uptake by human osteosarcoma (SaOS-2) cells and, if so, whether those effects would also be phosphate dependent. The results of these studies indicate that fluoride increased net 45Ca uptake by SaOS-2 cells, with biphasic dose and time dependencies. After 30 minutes of exposure, net 45Ca uptake was increased to a greater extent by 50 microM fluoride (217 +/- 16% of control, P < 0.001) than by 200 microM fluoride; and the stimulatory effect of 100 microM fluoride on net 45Ca uptake was greater after 20 minutes (187 +/- 22% of control, P < 0.001) than after 60 minutes (122 +/- 7% of control, P < 0.05). These effects of fluoride to increase net 45Ca uptake were dependent on the phosphate concentration in the medium. Fluoride had no effect on net 45Ca uptake in medium containing 0.4 mM phosphate, but increased net 45Ca uptake in medium containing 1.2 or 2.0 mM phosphate (P < 0.005). As the phosphate concentration was increased, the biphasic fluoride dose-response curve was shifted to a lower range of fluoride concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)
PMID: 8242471 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8154621&dopt=AbstractAnn Acad Med Stetin 1993;39:23-38
[Interaction of fluoride with milk constituents]
[Article in Polish]
Chlubek D.
Katedry i Zakladu Biochemii i Chemii Pomorskiej Akademii Medycznej.
Fluoride concentrations have been studied in cow milk stemming from regions variably influenced by fluorine pollution. It was disclosed that fluoride concentration in the milk of cows grazing on areas with a high degree of environmental contamination by fluorine compounds was about three-fold higher as compared to the control group. Fluoride distribution was evaluated in milk, in which the protein sediment got separated from the whey. The said distribution was found to be equal in both of the milk constituents. Due to the decomposition of whey into the whey proteins sediment and the remaining solution, an answer was obtained to the question of which part of whey fluoride appeared in the ionized form (80%). Studying the binding of fluoride by isolating and purifying the fraction of milk proteins at various pH, it was revealed that alpha-lactalbumin bound fluoride at 3.9 pH. Because of limited caseins solubility at that pH, there was no possibility to find out whether they bound fluoride ions. At fresh milk pH, the caseins exist in the anionic form and as such they are unable to bind fluoride independently. The binding of fluoride with milk lipids was investigated and it was ascertained that about 11% of fluoride being introduced into milk were bound to lipid constituent. The study covered also the influence of fluoride ions on the magnitude of the optic polarization angle of aqueous lactose solutions in different concentrations. That angle undergoes diminution in comparison with solutions not polluted by fluoride. Fluoride concentration was defined in some milk formulas of Polish production designed for infants. They exceed, depending on the kind of formulas, 20-70 fold the average fluoride concentration evidenced in human milk. Thus, the differences in fluoride supplied to infants, fed by breast and artificially, are very great.
PMID: 8154621 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8259489&dopt=AbstractSci Total Environ 1993 Sep 30;138(1-3):213-21
Studies on the leaching of fluoride in tea infusions.
Gulati P, Singh V, Gupta MK, Vaidya V, Dass S, Prakash S.
Department of Chemistry, Faculty of Science, Dayalbagh Educational Institute, Agra, India.
In order to assess the levels of fluoride ingestion through intake of tea, studies were conducted with four different brands of tea leaves commonly available in the Indian market. Four most prevalent methods for the preparation of tea with various contact times (2,4,6,8 and 10 min) of tea leaves with water show that:
(a) leaching of fluoride is least in case of leaf tea as compared to powdered tea (F levels increasing with decreasing grain size);
(b) leaching of fluoride reaches a maximum after a contact of about 6 min;
(c) there is no difference between levels of fluoride with or without addition of milk in the English style where tea leaves are not boiled, while for the Indian style, addition of milk and subsequent boiling resulted in reduction of fluoride levels and
(d) ingestion of fluoride per cup of tea ranged from 1.55 mg/l to 3.21 mg/l amounting to an intake per day per person of fluoride between 0.3 to 1.9 mg.
PMID: 8259489 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8406947&dopt=AbstractInt Arch Occup Environ Health 1993;65(1 Suppl):S95-8
Urine, serum and hair monitoring of hydrofluoric acid workers.
Kono K, Yoshida Y, Watanabe M, Orita Y, Dote T, Bessho Y.
Department of Hygiene and Public Health, Osaka Medical College, Japan.
To define the relationship between fluoride (F) concentration in the serum, urine and hair of workers and the concentration of hydrofluoric acid (HF) in the work environment, pre- and postshift serum and urine samples of 142 HF exposed workers and 237 unexposed workers were examined. Hair specimens were also collected for the determination of F. To determine whether external contamination influences hair analysis, the control hair samples were kept in the work environment for one week. The pre-exposure levels in serum and urinary F in HF workers were higher (P < 0.01) than the control values. This suggests that F excretion from the body continues for at least 12 hours. The postshift serum and urinary F concentrations of these workers were significantly higher (P < 0.01) than the preshift concentrations. The levels of F in the hair of HF workers were also higher than in the control subjects. The concentrations of F in postshift serum and urine, and hair were in good correlation to each other. There was a linear relationship between mean serum and urinary F concentrations and HF concentration in the workplace. A mean F concentration of 82.3 micrograms/l in serum and 4 mg/l in urine with a lower fiducial limit (95%, P = 0.05) of 57.9 micrograms/l in serum and 2 mg in urine were estimated to correspond to an atmospheric HF concentration of 3 ppm, which is the maximum allowable concentration recommended by Japan Association of Industrial Health and also the threshold limit value suggested by American Conference of Governmental Industrial Hygienists.(ABSTRACT TRUNCATED AT 250 WORDS)
PMID: 8406947 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8244437&dopt=AbstractIll Dent J 1993 May-Jun;62(3):165-9
Fluoride overfeeds in public water supplies.
Flanders RA, Marques L.
A description of the fluoride overfeed in Hooper Bay, Alaska, that resulted in the first reported death due to fluoride toxicity caused by drinking water from a community water system.
PMID: 8244437 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8365132&dopt=AbstractContact Dermatitis 1993 May;28(5):294
Contact urticaria from sodium fluoride.
Camarasa JG, Serra-Baldrich E, Lluch M, Malet A.
Allergo Centre, Josep Tarradellas, Barcelona, Spain.
PMID: 8365132 [PubMed - indexed for MEDLINE]
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8402809&dopt=AbstractCaries Res 1993;27(4):317-20
Enamel defects in 4- to 5-year-old children in fluoridated and non-fluoridated parts of Cheshire, UK.
Weeks KJ, Milsom KM, Lennon MA.
North Mersey Community Trust, Sefton General Hospital, Liverpool, UK.
The aim of this study was to compare the prevalence of developmental defects of enamel in the deciduous dentition of 4- to 5-year-old children residing in fluoridated (1 ppmF) and non-fluoridated (less than 0.2 ppmF) communities in Cheshire, UK. The significant difference in the prevalence of developmental defects of enamel between the two communities was accounted for by the higher prevalence of diffuse opacities in fluoridated Nantwich (29%), than in non-fluoridated Northwich (14%). The results also showed that when controlling for the age at which parents claimed toothbrushing commenced, the children in fluoridated Nantwich still had significantly more diffuse defects than the children in Northwich.
PMID: 8402809 [PubMed - indexed for MEDLINE]
Endemic Diseases Bulletin 1993; 8(3):53-56
- As cited and abstracted in Fluoride 1994; 27(3):161
Analysis of bone mineral content in cases of endemic skeletal fluorosis of different roentgen ray types
Jian-Yin Tian et al.
Scans were made of left ulna and radius bones with a 125 I photon beams for determination of bone mineral contents among 128 cases of endemic skeletal fluorosis. The results showed that the bone mineral contents were lower than those of normal controls, and varied according to the four types of condition revealed by the roentgen rays (early osteopathic changes, osteosclerosis, osteoporosis, and mixed osteopathic changes). The order of mineral contents, from high to low, was: osteosclerosis > early osteopathic changes > mixed osteopathic changes > osteoporosis.
Fluoride 1993; 26(1):3-22The effect of fluoride on higher plants
With special emphasis on early physiological and biochemical disordersGW Miller
Biology Department, Utah State University, Logan, Utah 84322-5305
Summary: One of the earliest manifestations of fluoride toxicity in plants is a change in respiratory rates. Either stimulation or inhibition occurs depending on a number of factors like plant species, concentraiton of fluoride, age of tissue, length of exposure, pH of culture medium and interaction between various mineral elements and fluoride. Fluoride-inhibited tissue respiration may be due in large part to inhibition of resspiratory enzymes. Succinic dehydrogenase and malic dehydrogenase have been shown in in vivo and in vitro experiments to be inhibited by physiological concentrations of fluoride.
The reasons for fluoride-stimulated respiration are less obvious. Special species of plants have shown an increased use of the pentose phosphate pathway when exposed to fluoride. The activities of glucose-6-phosphate dehydrogenase, cytochrome oxidase, catalase and perioxides were enhanced in fluoride inured tissues. The rise in respiration may be linked to fluoride as a phosphorylative uncoupler. When tissue respiration was enhanced in fluoride tissue (HF fumigation) ATPase activity of mitochondria was increased. This higher ATPase activity could result in increased ADP pools within the cell. Examination of the respiratory parameters of mitochrondria from corn that were exposed to fluoride exhibited increased oxygen consumption, reductions in respiratory control and ADP/O ratios. ATPase was inhibited using 30mM NaF. This is consistent with the reduced phosphorus/oxygen observed in mitochondria fluoride studies. Fluoride treatment of isolated mitochondria reduced the energized membrane potential and, since simultaneously increased respiration was observed, fluoride may have been acting as a week classic uncoupler.
We have reported the disruption of the tonoplast membrane and indicated it is the most fluoride-sensitive membrane as shown by electron microscopy. Tonoplast ATPase at 10 mM fluoride is inhibited. The maintenance of the transmembrane pH gradient is disrupted. Initially the chloride antiport movement inwardly during extrusion is blocked by fluoride competitively in the transport channel. Later ATPase was inhibited directly by fluoride. The ATPase in the plasmalemma membrane in sugarbeet was inhibited by fluoride as low as 5 mM. There was apparently formation of a MgF2 complex at the active site of the enzyme preventing binding of the normal Mg-ATP substrate.
There appear to be major diferences in the concentration of fluoride required to elicit the various responses between in vivo and in vitro experiments. This can be explained on the basis of subcellular fluoride partitioning. The basis for this model resides in the weak acid characteristics of HF (pKa 3.45), which would be in 2 forms, Hf and F-, and directly dependent on the pH of the immediate microenvironment. This can be calculated mathematically by the Henderson-Hasselbalch equation:
pH = pKa - log(F-)/(HF)
The two fluoride forms differ by 6 magnitudes in their ability to pass through lipid membranes. Thus concentration differences of fluoride between the apoplast (outside cell wall) and the cytoplasm, mitochondria and chloroplast would be great. If 1.9 ppm (parts per million) fluoride were in the apoplast (ph 5.8) then 47, 298 and 190 ppm would be found int he cytoplasm (pH 7.2), chloroplast (pH 8.0) and mitochrondria (pH 7.8), respectively.
Such a model indicates that low fluoride levels in the apoplast can be concentrated to high levels in organelles which could induce physiological damage. Such build-up of fluoride in the cytoplasm and organelles compared to the fluoride absorbed into the apoplasm may also explain cytogenetic effects of fluoride. A close relationship exists between calcium deficiency and chromosome abnormality. Treatment of chromosomes with EDTA causes dispersion of chromosomes through the dissolution of ionic bridges by the removal of calcium. Fluoride may also bind with calcium and destroy such ionic bridges.
Levels of ambient fluoride near an industrial plant were 200 ppb (parts per billion) (0.2 mg/m3). At 0.2 kilometer from the plant wheat leaf levels were over 500 ppm (dry weight basis) or about 3mM in undried leaf. A concentration in the cytoplasm could be in excess of 75mM. The percentage of mutations under these conditions was 2-6 times higher than the conrol and the spectrum of chromosome aberrations showed changes. Grain seedlings are highly sensitive to the mutagens in gaseous form such as HF.
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