ABSTRACT

Silicofluorides (SiFs), fluosilicic acid (FSA) and sodium fluosilicate (NaFSA), are used to fluoridate over 90% of US fluoridated municipal water supplies. Living in communities with silicofluoride treated water (SiFW) is associated with two neurotoxic effects: (1) Prevalence of children with elevated blood lead (PbB > 10 mg/dL) is about double that in non-fluoridated communities (Risk Ratio 2, x2 p < 0.01). SiFW is associated with serious corrosion of lead-bearing brass plumbing, producing elevated water lead (PbW) at the faucet. New data refute the long-prevailing belief that PbW contributes little to children’s blood lead (PbB), it is likely to contribute 50% or more. (2) SiFW has been shown to interfere with cholinergic function. Unlike the fully ionized state of fluoride (F-) in water treated with sodium fluoride (NaFW), the SiF anion, [SiF6]2- in SiFW releases F- in a complicated dissociation process. Small amounts of incompletely dissociated [SiF6]2- or low molecular weight (LMW) silicic acid (SA) oligomers may remain in SiFW. A German PhD study found that SiFW is a more powerful inhibitor of acetylcholinesterase (AChE) than NaFW. It is proposed here that SiFW induces protein mis-folding via a mechanism that would affect polypeptides in general, and explain dental fluorosis, a tooth enamel defect that is not merely ‘‘cosmetic’’ but a ‘‘canary in the mine’’ foretelling other adverse, albeit subtle, health and behavioral effects. Efforts to refute evidence of such effects are analyzed and rebutted. In 1999 and 2000, senior EPA personnel admitted they knew of no health effects studies of SiFs. In 2002 SiFs were nominated for NTP animal testing. In 2006 an NRC Fluoride Study Committee recommended such studies. It is not known at this writing whether any had begun.

Coplan et al, Confirmation Of And Explanations For Elevated Blood Lead And Other Disorders In Children Exposed To Water Disinfection And Fluoridation – NeuroToxicology 28 (2007) 1032–1042

SUMMARY

Ninety children with dental fluorosis, aged 7–18, living in fluoride endemic, non-iodine deficient areas of the National Capital Territory of Delhi, India, where iodized salt has been promoted for over a decade, were investigated, along with 21 children in two control groups without dental fluorosis living in nonendemic areas, to determine their levels of free T4 (FT4), free T3 (FT3), and thyroid stimulating hormone (TSH). The drinking water fluoride of the 90 children in the sample group ranged from 1.1 to 14.3 mg F–/L (mean 4.37 mg F–/L); their serum ranged from 0.02 to 0.41 mg F–/L (mean 0.14 mg F–/L); their urine ranged from 0.41 to 12.8 mg F–/L (mean 3.96 mg F–/L).

The drinking water fluoride of the control 1 group (n = 10) ranged from 0.14 to 0.81 mg F–/L (mean 0.23 mg F–/L) and that of the control II group (n = 11) ranged from 0.14 to 0.73 mg F–/L (mean 0.41 mg F–/L). In control I, only 3 children had serum fluoride below the normal upper limit of 0.02 mg F–/L. The remaining 7 children, even though they were consuming “safe” water, had elevated serum fluoride. In control II, only one child had serum fluoride below the normal upper limit. The remaining 8 children who were tested also had elevated serum fluoride. In control I, only 3 children had urine fluoride samples in the normal range (0.09–0.10 mg F–/L); in the remaining 7 children they were above normal. In control II, only one child had urinary and serum fluoride within the normal range. In the remaining 8 children who were tested it was high, suggesting they had excess F– exposure from sources other than drinking water.

The hormonal status of the 90 sample children indicated that 49 (54.4%) had well-defined hormonal derangements. In the remaining 41 children the findings were borderline. The hormonal deviations among the affected 49 children fall into the following five categories: (1) high TSH with normal FT4 and FT3 (46.9%); (2) normal TSH and FT4 with low FT3 (32.7%); (3) high TSH and FT3 with normal FT4 (14.3%); (4) high TSH with normal FT3 but low FT4 (4.1%); and (5) high TSH with normal FT4 but low FT3 (2.0%). In control I and control II, similar hormonal deviations were detected in as many as 50% and 45.4% of the children, respectively.

These findings indicate that children with or even without dental fluorosis from exposure to excess fluoride, either through drinking water or through other sources, may have thyroid hormone derangements that may not be clinically overt until late stages. Determining free T3, free T4, and TSH is therefore important for a proper diagnosis of potential health problems. Withdrawal from fluoride sources along with measures to correct the thyroid hormonal status may be necessary to promote better health in such children living in fluoride endemic areas.

Susheela et al, Excess Fluoride Ingestion & Thyroid Hormone Derangements In Children Living In Delhi, India – Fluoride 2005 38(2) 151–161

SUMMARY

Beginning in 1983 and continuing through 1986, fluoride discharges from the aluminum plant were greatly reduced. This was initially due to modifications in the plant’s pollution-discharge system. However, it was also during this period that the Washington Department of Ecology (WDOE) took an active interest in the results of the CZES Division’s water quality and behavior tests. The WDOE lowered significantly the discharge limitations for a number of contaminants, including fluoride, in the aluminum plant’s wastewater discharge permit. With the reduction in fluoride discharged from the aluminum plant, there was a corresponding drop in fluoride concentrations in the river near the outfall and John Day Dam. Concurrently, fish passage delays and interdam losses of adult salmon decreased to acceptable levels.

Effects Of Fluoride On Fish Passage – NOAA 1993 Technical Memorandum On Damkaer & Dey 1989 Published Study

Damkaer & Dey, Evidence For Fluoride Effects On Salmon Passage At John Day Dam, Columbia River, 1982-1986 – North American Journal Of Fisheries Management 9154-162, 1989

ABSTRACT

This study concerns effects on water-borne lead from combinations of chlorine (CL) or chloramines (CA) with fluosilicic acid (FSA) or sodium fluoride (NaF). CL is known to corrode brass, releasing lead from plumbing devices. It is known that CA and CL in different ratios with ammonia (NH) mobilize copper from brass, which we have found also enhances elution of lead from leaded brass alloys. Phase I involved leaded-brass 1/4 in.elbows pre-conditioned in DI water and soaked in static solutions containing various combinations of CL, CA, FSA, NaF, and ammonium fluosilicate. In Phase II 20 leaded-brass alloy water meters were installed in pipe loops. After pre-conditioning the meters with 200 flushings with 1.0 ppm CL water, seven different solutions were pumped for a period of 6 weeks. Water samples were taken for lead analysis three times per week
after a 16-h stagnation period. In the static testing with brass elbows, exposure to the waters with CA + 50% excess NH3 + FSA, with CA and ammonium fluosilicate, and with CA + FSA resulted in the highest estimated lead concentrations. In the flow-through brass meter tests, waters with CL + FSA, with CL + NaF, and with CL alone produced the highest average lead concentration for the first 3-week period. Over the last 3 weeks the highest lead concentrations were produced by CL + NaF, followed by CL alone and CA + NH3 + FSA. Over the first test week (after CL flushing concentrations were increased from 1.0 to 2.0 ppm) lead concentrations nearly doubled (from about 100 to nearly 200 ppb), but when FSA was also included, lead concentrations spiked to over 900 ppb. Lead concentrations from the CL-based waters appeared to be decreasing over the study
period, while for the CA + NH3 + FSA combination, lead concentrations seemed to be increasing with time.

Maas et al, Effects Of Fluoridation And Disinfection Agent Combinations On Lead Leaching From Leaded-Brass Parts – NeuroToxicology 28 (2007) 1023–1031

ABSTRACT

The aim of this paper was to critically review the current role of community water fluoridation in preventing dental caries. Original articles and reviews published in English language from January 2001 to June 2006 were selected through MEDLINE database. Other sources were taken from the references of the selected papers. For the past 50 years community water fluoridation has been considered the milestone of caries prevention and as one of the major public health measures of the 20th century. However, it is now accepted that the primary cariostatic action of fluoride occurs after tooth eruption. Moreover, the caries reduction directly attributable to water fluoridation have declined in the last decades as the use of topical fluoride had become more widespread, whereas enamel fluorosis has been reported as an emerging problem in fluoridated areas. Several studies conducted in fluoridated and nonfluoridated communities suggested that this method of delivering fluoride may be unnecessary for caries prevention, particularly in the industrialized countries where the caries level has became low. Although water fluoridation may still be a relevant public health measure in poor and disadvantaged populations, the use of topical fluoride offers an optimal opportunity to prevent caries among people living in both industrialized and developing countries.

Pizzo et al, Community Water Fluoridation And Caries Prevention – A Critical Review, Clinical and Oral Investigations 14-Feb-2007

ABSTRACT

Objectives: To compare prevalence and incidence of caries between fluoridation-ended and still-fluoridated communities in British Columbia, Canada, from a baseline survey and after three years.

Methods: At the baseline (1993/4 academic year) and follow-up (1996/7) surveys, children were examined at their schools. Data were collected on snacking, oral hygiene, exposure to fluoride technologies, and socio-economic level. These variables were used together with D1D2MFS indices in multiple regression models.

Results: The prevalence of caries (assessed in 5927 children, grades 2, 3, 8, 9) decreased over time in the fluoridation ended community while remaining unchanged in the fluoridated community. While numbers of filled surfaces did not vary between surveys, sealed surfaces increased at both study sites. Caries incidence (assessed in 2994 life-long residents, grades 5, 6, 11, 12) expressed in terms of D1D2MFS was not different between the still-fluoridating and fluoridation-ended communities. There were, however, differences in caries experienced when D1D2MFS components and surfaces at risk were investigated in detail. Regression models did not identify specific variables markedly affecting changes in the incidence of dental decay.

Conclusions: Our results suggest a complicated pattern of disease following cessation of fluoridation. Multiple sources of fluoride besides water fluoridation have made it more difficult to detect changes in the epidemiological profile of a population with generally low caries experience, and living in an affluent setting with widely accessible dental services. There are, however, subtle differences in caries and caries treatment experience between children living in fluoridated and fluoridation-ended areas.

Discover Greater Findings About This Fluoridation-Ended Community Research

Maupome´et al, Patterns Of Dental Caries Following The Cessation Of Water Fluoridation, Community Dentistry And Oral Epidemiology, (2001) 29 37–47

ABSTRACT

Background: Caries on children and adolescents in Denmark has declined significantly over the last 30 years. Our first analysis in 1999, however, disclosed huge inter-municipality disparities in mean DMFS values as well as in prevalence of caries on Danish children; that fluoride in the water supply and the length of the education of the mothers could explain up to 45% of the above-mentioned disparity and that very few municipalities were positive outliers, i.e. were providing significant better caries results than expected from the background variables. Three of the aims of this second analysis were to repeat the analyses done on the 1999 sample, but now on a 2004 sample and then compare it with the results from 1999. A fourth aim was by means of an interview of CDOs to determine their interpretation of relevant conditions in the public dental health service in relation dental health outcome.

Methods: A total of 204 (99%) and 191 (93%) municipalities were involved in 1999 and 2004, respectively. Unit of analysis were the municipalities. Mean DMFS of 15-year-olds was used as outcome variable. Eight background variables were accounted for during the analysis: For the fourth aim, a sample of CDOs representing municipalities with positive (n = 10), with no change (n = 10), or with negative change (n = 10) in mean DMFS, relative to all municipalities, between 1999 and 2004 was selected.

Results: The inter-municipality variation in mean DMFS 1999 was 0.88 to 8.73 and in 2004 was 0.56 to 6.19. The analyses found that fluoride level of the drinking water and mothers’ length of education were significant variables explaining about 44% of the variations in mean DMFS in both years. Only one municipality was characterized as a positive outlier in 1999 as well as in 2004. The dose-response relations between increasing fluoride concentrations in the water supply and DMF-S values diminished in both years at a level above 0.35 ppm. The structured interview disclosed that municipalities with significant improvement in mean DMFS from 1999 to 2004 had established goals and were committed to the prevention of dental caries at the individual level. Instability in manpower; number of children in the service and economy was associated to municipalities with negative changes in caries experience.

Ekstrand et al, Factors Associated With Inter-Municipality Differences In Dental Caries Experience Among Danish Adolescents, An Ecological Study – Community Dentistry And Oral Epidemiology 2009

ABSTRACT

Objective: The objective of this study was to evaluate associations between patterns of infant formula feeding and dental fluorosis and caries in a representative sample of Australian children.

Methods: A population-based study gathered information on fluoride exposure in early childhood. Information on infant formula feeding and fluoridation status was used to group children: three groups in nonfluoridated areas (formula nonuser, user for <6 months, and user for 6+ months) and four groups in fluoridated areas (nonuser, user with nonfluoridated water, user with fluoridated water for <6 months, and user with fluoridated water for 6+ months). Children aged 8-13 years were examined for fluorosis using the Thylstrup and Fejerskov (TF) Index. Primary tooth caries experience recorded at age 8-9 years was extracted from clinical records. Fluorosis cases were defined as having TF 1+ on maxillary incisors. Fluorosis prevalence and primary caries experience were compared across formula user groups in multivariable regression models adjusting for other factors.

Results: Total sample was 588 children. Children in fluoridated areas had higher prevalence of very mild to mild fluorosis, but lower caries experience than those in nonfluoridated areas. Among children in nonfluoridated areas, formula users for 6+ months had significantly higher prevalence of fluorosis compared with nonusers. There was no significant difference in fluorosis prevalence among the formula users in fluoridated areas. Among children in fluoridated areas, formula users with nontap water had higher caries experience.

Conclusion: Infant formula use was associated with higher prevalence of fluorosis in nonfluoridated areas but not in fluoridated areas. Type of water used for reconstituting infant formula in fluoridated areas was associated with caries experience.

Do, Levy and Spencer – Association Between Infant Formula Feeding And Dental Fluorosis And Caries In Australian Children, Journal Of Public Health Dentistry, 2011

ABSTRACT

Objectives: To determine changes in the prevalence of dental fluorosis, and in perceptions of aesthetic concerns due to dental fluorosis after water fluoridation ceased.

Methods: Schoolchildren in second and third grades were examined in 1993–94, 1996–97 and 2002–03 to determine changes in the prevalence of dental fluorosis following fluoridation cessation of the public water supplies in 1992. The Thylstrup–Fejerskov Index (TFI) was used to quantify dental fluorosis. Perceptions of aesthetics were assessed by questionnaires which were sent home to parents. Residence and dental histories were confirmed on all children to determine the extent of exposure to all types of fluorides. Comparisons between the three surveys were used to establish the influence of fluoridated water and other fluoride sources on the occurrence and severity of dental fluorosis. Aesthetic ratings from parents were used to assess the aesthetic conditions of maxillary anterior teeth across the three surveys.

Results: When fluoride was removed from the water supply in 1992, the prevalence and severity of TFI scores decreased significantly from the 1993–94 survey cycle when compared with the 1996–97 and 2002–03 survey cycles. The use of fluoride supplements and fluoride dentifrice also decreased during this study period. Analyses were unable to determine the influence of these different fluoride exposures on the changes in TFI scores over time. Comparisons of aesthetic ratings from parents between survey cycles failed to show any significant differences.

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Clark et al, Changes In Dental Fluorosis Following The Cessation Of Water Fluoridation Community Dentistry And Oral Epidemiology, (2006) 34 197–204

SUMMARY

A statement concerning the ethics of water fluoridation was published in a recent issue of the Journal of the Canadian Dental Association.1 The arguments presented in that paper did not constitute what we would consider a complete and systematic account of the scientific and moral issues involved. It is our contention that water fluoridation, by the very nature of the way it is administered, engenders a number of moral dilemmas that do not admit to any easy solution. In this paper, we attempt to elucidate the particular problems posed by this public health initiative, according to the principles of bioethics.

Cohen and Locker – The Science And Ethics Of Water Fluoridation – Journal Canadian Dental Association, 2001 67(10)578-80