March 21, 2019

Zohoori et al, Impact of Water Fluoride Concentration on the Fluoride Content of Infant Foods and Drinks Requiring Preparation With Liquids Before Feeding


Objectives: To measure the fluoride (F) content of infant foods and drinks requiring reconstitution with liquids prior to consumption and to determine the impact of water F concentration on their F content, as consumed, by measuring F content before and after preparation. Methods: In total, 58 infant powdered formula milks, dry foods and concentrated drinks were prepared with deionized water (<0.02 ppm F) nonfluoridated (0.13 ppm F) and fluoridated (0.90 ppmF) water. The F concentrations of drink samples were measured directly using a fluoride-ion-selective electrode after addition of TISAB III, and food samples and formula milks measured indirectly by an acid diffusion method. Results: The overall range of F concentrations of all the nonreconstituted samples, in their prepreparation dry or concentrated forms, was from 0.06 to 2.99 lg/g with the highest F concentration for foods found in
the dry ‘savoury meals’ (a combination of vegetables and chicken or cheese or rice) group. However, when the samples were reconstituted with nonfluoridated water, the mean F concentrations of prepared ‘concentrated juices’, ‘pasta and rice’, ‘breakfast cereals’, ‘savoury meals’ and ‘powdered infant formula milks’ were 0.38, 0.26, 0.18, 0.16 and 0.15 lg/g, respectively. The corresponding mean F concentrations were 0.97, 1.21, 0.86, 0.74 and 0.91 lg/g, respectively, when the same samples were prepared with fluoridated water.

Conclusion: Although some nonreconstituted infant foods/drinks showed a high F concentration in their dry or concentrated forms, the concentration of F in prepared foods/drinks primarily reflected the F concentration of liquid used for their preparation. Some infant foods/drinks, when reconstituted with fluoridated water, may result in a F intake in infants above the suggested optimum range (0.05–0.07 mg F/kg body weight) and therefore may put infants at risk of developing dental fluorosis. Further research is necessary to determine the actual F intake of infants living in fluoridated and nonfluoridated communities using reconstituted infant foods and drinks.

Zohoori et al, Impact Of Water Fluoride Concentration On The Fluoride Content Of Infant Foods And Drinks Requiring Preparation With Liquids Before Feeding, Community Dentistry And Oral Epidemiology 01-Mar-2012

Do, Levy and Spencer, Association Between Infant Formula Feeding and Dental Fluorosis and Caries in Australian Children


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

Bahr, Water Fluoridation – The Risks and Benefits, Carroll University Thesis, Waukesha, Wisconsin


The purpose of this research project was to assess community members understanding of water fluoridation, and whether benefit and risk education changes perspective toward water fluoridation. The study used quantitative method research design. A survey was conducted in which fifty nine participants were surveyed before and after educational material about water fluoridation. This research design focused on 1) what are the risks and benefits of water fluoridation, 2) how much docs the public understand about water fluoridation, 3) should there be more educational material about water fluoridation.

The results indicated that with education about water fluoridation there is a shift in attitude towards water fluoridation. Understanding of the risks and benefits increased from 10.2% to 84.7%, and indicated that with more education participants were less likely to drink fluoridated water.

Bahr, Water Fluoridation – The Risks And Benefits (Thesis) Carroll University, Waukesha, Wisconsin Dec-2010

Sawan, Fluoride Increases Lead Concentrations In Whole Blood And In Calcified Tissues From Lead-Exposed Rats


Higher blood lead (BPb) levels have been reported in children living in communities that receive fluoride treated water. Here, we examined whether fluoride co-administered with lead increases BPb and lead concentrations in calcified tissues in Wistar rats exposed to this metal from the beginning of gestation.We exposed female rats and their offspring to control water (Control Group), 100 mg/L of fluoride (F Group), 30 mg/L of lead (Pb Group), or 100 mg/L of fluoride and 30 mg/L of lead (F + Pb Group) from 1 week prior to mating until offspring was 81 days old. Blood and calcified tissues (enamel, dentine, and bone) were harvested at day 81 for lead and fluoride analyses. Higher BPb concentrations were found in the F + Pb Group compared with the Pb Group (76.7±11.0 μg/dL vs. 22.6±8.5 μg/dL, respectively; p < 0.001). Two to threefold higher lead concentrations were found in the calcified tissues in the F + Pb Group compared with the Pb Group (all p < 0.001). Fluoride concentrations were similar in the F and in the F + Pb Groups. These findings show that fluoride consistently increases BPb and calcified tissues Pb concentrations in animals exposed to low levels of lead and suggest that a biological effect not yet recognized may underlie the epidemiological association between increased BPb lead levels in children living in water-fluoridated communities.

Sawan, Fluoride Increases Lead Concentrations In Whole Blood And In Calcified Tissues From Lead-Exposed Rats, Toxicology 271 (2010) 21–26

Ding et al, The Relationships Between Low Levels of Urine Fluoride on Children’s Intelligence, Dental Fluorosis in Endemic Fluorosis Areas in Hulunbuir, Inner Mongolia, China


There has been public concern about children’s intellectual performance at high levels of fluoride exposure, but few studies provide data directly to the question of whether low fluoride exposure levels less than 3.0 mg/L in drinking water adversely associated with children’s intelligence. In this survey,weinvestigated the effects of low fluoride exposure on children’s intelligence and dental fluorosis. 331 children aged from 7 to 14 were randomly recruited from four sites in Hulunbuir City, China. Intelligence was assessed using Combined Raven Test-The Rural in China while dental fluorosis was diagnosed with Dean’s index. Mean value of fluoride in drinking water was 1.31±1.05 mg/L (range 0.24–2.84). Urine fluoride was inversely associated with IQ in the multiple linear regression model when children’s age as a covariate variable was taken into account (P < 0.0001). Each increase in 1 mg/L of urine fluoride associated with 0.59-point decrease in IQ (P = 0.0226). Meanwhile, there was a dose–response relationship between urine fluoride and dental fluorosis (P < 0.0001). In conclusion, our study suggested that low levels of fluoride exposure in drinking water had negative effects on children’s intelligence and dental health and confirmed the dose–response relationships between urine fluoride and IQ scores as well as dental fluorosis.

Ding et al, The Relationships Between Low Levels Of Urine Fluoride On Children’s Intelligence, Dental Fluorosis In Endemic Fluorosis Areas In Hulunbuir, Inner Mongolia, China, J. of Hazardous Materials 186 (2010) 1942–1946

Quiñonez & Locker, Public Opinions On Community Water Fluoridation

Background: Community water fluoridation (CWF) is currently experiencing social resistance in Canada. Petitions have been publicly registered, municipal plebiscites have occurred, and media attention is growing. There is now concern among policy leaders whether the practice is acceptable to Canadians. As a result, this study asks: What are public opinions on CWF?

Methods: Data were collected in April 2008 from 1,005 Canadian adults by means of a national telephone interview survey using random digit dialling and computer-assisted telephone interview technology. Descriptive and bivariate and multivariate logistic regression analyses were undertaken.

Results: Approximately 1 in 2 Canadian adults surveyed knew about CWF. Of these, 80% understood its intended use, approximately 60% believed that it was both safe and effective, and 62% supported the idea of having fluoride added to their local drinking water. Those with greater incomes [OR=1.4; p<0.001] and education [OR=1.6; p<0.001] were more likely to know about CWF. Those with greater incomes [OR=1.3; p<0.03] and those who visited the dentist more frequently [OR=1.8; p<0.002] were more likely to support CWF, and those with children [OR=0.5; p<0.02], those who accessed dental care using public insurance [OR=0.2; p<0.03], and those who avoided fluoride [OR=0.04; p<0.001] were less likely to support CWF.

Conclusion: It appears that Canadians still support CWF. In moving forward, policy leaders will need to attend to two distinct challenges: the influence of anti-fluoride sentiment, and the potential risks created by avoiding fluoride.

Quiñonez & Locker, Public Opinions On Community Water Fluoridation, Canadian Public Health Association, 2009 100(2) 96-100

Ekstrand et al, Factors Associated with Inter-Municipality Differences in Dental Caries Experience Among Danish Adolescents


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

Rocha-Amador et al, Use of the Rey-Osterrieth Complex Figure Test for Neurotoxicity Evaluation of Mixtures in Children


The aim of this study was to assess the value of the children’s version of the Rey-Osterrieth Complex Figure Test as a screening test in a population exposed to different mixtures of neurotoxicants. Copy and Immediate Recall scores were evaluated through the test. Children were recruited from three sites; an area with natural contamination by fluoride and arsenic (F–As), a mining-metallurgical area with lead and arsenic contamination (Pb–As) and a malaria zone with the evidence of fish contaminated with dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs). Children aged 6–11 years old, living in one of the three polluted sites since birth were recruited (n = 166). The exposure was evaluated as follows: fluoride and arsenic in urine, lead in blood and DDT, dichlorodiphenyldichloroethylene (DDE) and PCBs in serum. To evaluate the test performance, z-scores for Copy and Immediate Recall were calculated. The proportion of children by residence area with performance lower than expected by age (below 1 SD) for Copy and Immediate Recall was in the F–As area (88.7% and 59%) and in the DDT–PCBs area (73% and 43.8%), respectively. In the Pb–As area, the proportion was 62% for both tests. After adjustment, Copy correlated inversely with fluoride in urine (r = 0.29; p < 0.001) and Immediate Recall correlated inversely with fluoride in urine (r = 0.27; p < 0.05), lead in blood (r = 0.72; p < 0.01), arsenic in urine (r = 0.63; p < 0.05) and DDE (r = 0.25; p < 0.05). This study provided evidence that children included in this research are living in high risk areas and were exposed to neurotoxicants. Poor performance in the test could be explained in some way by F, Pb, As or DDE exposure, however social factors or the low quality of school education prevalent in the areas could be playing an important role.

Rocha-Amador et al, Use of the Rey-Osterrieth Complex Figure Test for Neurotoxicity Evaluation of Mixtures in Children 19-Sep-2009


Vukmanich, Effects of Fluoridating Agents on Water Chemistry – Thunder Bay, Ontario


The water chemistry of Thunder Bay treated water poses unique problems for additional treatments and especially corrosion control.

This report describes the effects of three fluoridating agents on the chemistry of Thunder Bay drinking water and in particular their effect on lead-pipe corrosion. Static corrosion tests were performed with hydrofluorosilicic acid (H2SiF6), sodium silicofluoride (Na2SiF6), and sodium fluoride (NaF), each at concentration levels of 0.5, 0.7, 1.5 parts per million as fluoride ion. One additional experiment was conducted using a pH ( pH=8.5) adjusted solution of hydrofluorosilicic acid at each of the three levels. The static corrosion tests used lead coupons that were fabricated from common lead water supply pipe. The experiments measured the amount of lead leached into solution from the coupons immersed in the solution of the fluoridating agent. Fixed samplings at 6, 24, 96, 168, and 360 hours were analysed.

The fluoridating agent that caused the greatest amount of lead leaching was the solution of un-buffered hydrofluorosilicic at a concentration of 0.7 ppm. The rate was about 2.6 times the control. When the same hydrofluorosilicic acid is used in a pH adjusted solution (pH=8.5) the relative corrosion rate was about 8 times lower, than the un-buffered acid.

Sodium silicofluoride was found to have a relative corrosion rate of about 1.4 times lower then free hydrofluorosilicic acid.

The solution of sodium fluoride at 0.7 ppm as fluoride had the lowest corrosion rate.

The findings show that all the fluoridating agents chosen increase the corrosion of lead pipe to some extent in Thunder Bay tap water. The pH adjusted hydrofluorosilicic acid appears to be the best compromise since it had the next lowest corrosion rate. This choice would require an additional neutralizing agent, sodium hydroxide for pH adjustment.

Vukmanich, Effects Of Fluoridating Agents On Water Chemistry – Thunder Bay, Ontario 2009

Tang et al, Fluoride and Children’s Intelligence: A Meta-analysis


This paper presents a systematic review of the literature concerning fluoride that was carried out to investigate whether fluoride exposure increases the risk of low intelligence quotient (IQ) in China over the past 20 years. MEDLINE, SCI, and CNKI search were organized for all documents published, in English and Chinese, between 1988 and 2008 using the following keywords: fluorosis, fluoride, intelligence, and IQ. Further search was undertaken in the website because this is a professional website concerning research on fluoride. Sixteen case–control studies that assessed the development of low IQ in children who had been exposed to fluoride earlier in their life were included in this review. A qualitative review of the studies found a consistent and strong association between the exposure to fluoride and low IQ. The meta-analyses of the case–control studies estimated that the odds ratio of IQ in endemic fluoride areas compared with nonfluoride areas or slight fluoride areas. The summarized weighted mean difference is −4.97 (95%confidence interval [CI]=−5.58 to −4.36; p<0.01) using a fixed-effect model and −5.03 (95%CI=−6.51 to 3.55; p<0.01) using a random-effect model, which means that children who live in a fluorosis area have five times higher odds of developing low IQ than those who live in a nonfluorosis area or a slight fluorosis area.

Tang Q-Q, Du J, Ma H-H, Jiang S-J, Zhou X-J. – Fluoride and Children’s Intelligence – A Meta-Analysis – Biological Trace Element Research 126 115-120 Humana Press, 2008