Tag Archives: fluoridation

Water fluoridation contributes to fluoride overexposure

Patil MM, Lakhkar BB, Patil SS. Curse of Fluorosis. Indian J Pediatr. 2018 Jan 3. doi: 10.1007/s12098-017-2574-z.

Fluoride was identified to have caries preventive properties and was widely used for fluoridation of water since 1940, especially in developed countries. After this there was sudden increase in the use of fluorides in food items and in oral medicinal products like toothpastes and mouth washes. Inadvertent use of above has lead to increase in fluorosis as a public health problem. In many places high fluorides are naturally present in earth crust leading to high water fluoride content increasing the risk of fluorosis. Maintaining a fine balance of fluorides in the body is mandatory for exploiting its advantages. World Health Organization (WHO) has fixed permissible limit of fluorides in water to 1.5 mg/L as a preventive step to contain fluorosis. Fluorosis has three clinical components: Dental, Skeletal and Non-Skeletal Fluorosis. It occurs with increasing level of fluorides in the body. Acute toxicity due to fluorides is also known and occurs as a result of sudden exposure to high levels of fluorides, usually by ingestion. Once fluorosis occurs it is irreversible without any cure. Only symptomatic and supportive management is possible. Hence prevention is the mainstay of management. Prevention is by using alternative sources of water or its de-fluoridation. National Program for Prevention and Control of Fluorosis (NPPCF) was launched in 2008-9 to identify areas with high fluoride content of water, manage the water bodies, screen schools and community for fluorosis and comprehensive management of cases. Improving quality of drinking water as per standards and improving nutritional status of children are also important components of prevention of fluorosis.

Fluoride Effects IQ of 12-14 Year-Old Children, India

Razdan P, Patthi B, Kumar JK, Agnihotri N, Chaudhari P, Prasad M. Effect of Fluoride Concentration in Drinking Water on Intelligence Quotient of 12-14-Year-Old Children in Mathura District: A Cross-Sectional Study. Journal of International Society of Preventive and Community Dentistry. 2017 Sep-Oct;7(5):252-258. doi: 10.4103/jispcd.JISPCD_201_17.

AIMS: The aim was to assess and correlate the influence of the concentration of fluoride in ingested water on the intelligence quotient (IQ) of 12-14-year-old youngsters in Mathura district.

MATERIALS AND METHODS: A total of 219 children were selected, 75 from low F area, 75 medium F area, and 69 from high F area. The concentration of fluoride in the routinely ingested water was estimated using “Ion Selective Electrode method”; then, Raven’s Test was utilized to estimate the IQ of the study participants. Independent t-test, Tukey’s post hoc, Chi-square an analysis of variance tests were used to associate the mean and proportion IQ scores in high-, medium-, and low-fluoride regions along with inter-group significant differences (P ≤ 0.05).

RESULTS: The comparison of IQ score showed that 35 (46.7%) participants from the high fluoride and 10 (13.3%) participants from the medium-fluoride areas had below average IQ. Further, it was noted that the lowest mean marks were obtained by the children in the high-fluoride region (13.9467) followed by those in medium (18.9467) and uppermost in least noted fluoride area (38.6087). However, gender-based intergroup comparison did not produce a significant relation with fluoride (P ≥ 0.05).

CONCLUSION: Concentration of Fluoride in the ingested water was significantly associated with the IQ of children. It has also coined the proportional variability in mental output in accordance to the ingested fluoride level. As two sides of a coin, fluoride cannot be utterly blamed for a lower intelligence in a population; it puts forward a fact that intelligence is a multifactorial variable with a strategic role played by genetics and nutrition to develop cognitive and psychosomatic activities in an individual.

Early Concerns about Water Fluoridation Ignored Resulting in a Presumption of Safety

Adding fluoride to drinking water is the sacred cow for advocates within the dental community (e.g. here). Much has been written on this topic and many articles can be found on this blog and other sites. The presumption of safety was imposed and institutionalized early on. But evidence is not neutral. The assumptions of the interpreter determine what conclusions are reached based on the evidence. The historical presumption of safety (it is safe until proven that it is not) has result the same conclusion of safety by every government or association panel evaluation of fluoridation. But evidence-based hazards and risks have been completely ignored or downplayed from the beginning of the practice. Indeed, organizations simply repeat the same song typically endorsing each others endorsement. The absence of dead bodies in the street or repetitive results from ecological studies interpreted using particular statistical tests is simply not sufficient justification for continuing the practice. But it continues nevertheless…

C Carstairs Debating Water Fluoridation Before Dr. Strangelove. American Journal of Public Health. 2015;105:1559–1569. doi:10.2105/AJPH.2015.302660.

In the 1930s, scientists learned that small amounts of fluoride naturally occurring in water could protect teeth from decay, and the idea of artificially adding fluoride to public water supplies to achieve the same effect arose. In the 1940s and early 1950s, a number of studies were completed to determine whether fluoride could have harmful effects. The research suggested that the possibility of harm was small. In the early 1950s, Canadian and US medical, dental, and public health bodies all endorsed water fluoridation. I argue in this article that some early concerns about the toxicity of fluoride were put aside as evidence regarding the effectiveness and safety of water fluoridation mounted and as the opposition was taken over by people with little standing in the scientific, medical, and dental communities. The sense of optimism that infused postwar science and the desire of dentists to have a magic bullet that could wipe out tooth decay also affected the scientific debate. 

Hydrofluosilicic acid study avoids the key issue

This study looks at arsenic as an impurity in a chemical used to add fluoride to drinking water. The NSF/ANSI standard 60 addresses these questions and making such studies generally unnecessary. What is overlooked is the obvious question is whether adding fluoride to water is a benefit at all. Indeed, it has become a sacred cow enabling advocates to feel good about themselves preventing dental decay without actually having much of a benefit.

Peterson E, Shapiro H, Li Y, Minnery JG, Copes R. Arsenic from community water fluoridation: quantifying the effect. Journal of water and health. 2016 Apr;14(2):236-42. doi: 10.2166/wh.2015.105.

Community water fluoridation is a WHO recommended strategy to prevent dental carries. One debated concern is that hydrofluorosilicic acid, used to fluoridate water, contains arsenic and poses a health risk. This study was undertaken to determine if fluoridation contributes to arsenic in drinking water, to estimate the amount of additional arsenic associated with fluoridation, and compare this to the National Sanitation Foundation/American National Standards Institute (NSF/ANSI) standard and estimates from other researchers. Using surveillance data from Ontario drinking water systems, mixed effects linear regression was performed to examine the effect of fluoridation status on the difference in arsenic concentration between raw water and treated water samples. On average, drinking water treatment was found to reduce arsenic levels in water in both fluoridated and non-fluoridated systems by 0.2 μg/L. However, fluoridated systems were associated with an additional 0.078 μg/L (95% CI 0.021, 0.136) of arsenic in water when compared to non-fluoridated systems (P = 0.008) while controlling for raw water arsenic concentrations, types of treatment processes, and source water type. Our estimate is consistent with concentrations expected from other research and is less than 10% of the NSF/ANSI standard of 1 μg/L arsenic in water. This study provides further information to inform decision-making regarding community water fluoridation.

Baltimore Water Fluoridation Today Continues Mistake of the Past

Baltimore did have a role in the institutionalization of communal water fluoridation. Dr. Abel Wolman of Johns Hopkins University strongly opposed the addition of fluoride. But his mind was changed by arm-twisting from water industry interests. Wolman was clearly on the right track in opposing fluoridation until industry stepped in. Continued support for addition of fluoride to water is simply based on circular reasoning. 

Daws S. Baltimore and the Beginnings of the Fluoride Controversy. Journal of the history of dentistry. 2015 Summer-Fall;63(2):54-63.

The fluoridation of municipal water as a preventive dental health measure has proven to be a contentious issue from its very outset. In 1952, Baltimore became the first major city in the United States to artificially add fluoride to its water supply. This study draws largely on print media sources as a means of discerning public sentiment, in order to evaluate the nature of Baltimore’s fluoride controversy in its infancy. Initial response was influenced by prior exposure to the substance within the context of dentistry, as well as a continued trend of conservatism within the community. Logistical issues during implementation due to the necessary upscale of established practices to accommodate Baltimore’s population served to further exacerbate concerns. Much of the opposition was predicated on the breadth of the measure, as evidenced by the myriad of personal concerns put forth in objection. Personal concerns developed into demands for personal autonomy, providing a philosophical foundation for the anti-fluoridation movement that persists today.

Protecting the “Water Fluoridation” Status Quo

Once the ideas became institutionalized in the 1950s that water fluoridation was a necessity for dental health (it is not) and that there was a magical “optimum” fluoride concentration (there isn’t) two presumptions were established. The first presumption is that fluoride added to drinking water is safe and without harm.  The second was that anyone who questions the practice of intentionally adding fluoride to drinking water is a nut case, a fool, and “anti” as they have been called.

Well regardless these two presumptions are false. Indeed, intentional communal fluoridation as a prudent public health practice will continue to be questioned (and opposed) by thinking people because of the evidence, not in spite of it. Studies such as this simply observe  and conclude what has been assumed in advance. Such studies are thrown on to the pile of prior studies over the decades which have the same starting assumptions. Though well intentioned such studies fall short of answering the most important questions regarding fluoride addition to drinking water.

McLaren L, Patterson S, Thawer S, Faris P, McNeil D, Potestio M, Shwart L. Measuring the short-term impact of fluoridation cessation on dental caries in Grade 2 children using tooth surface indices. Community Dentistry and Oral Epidemiology. 2016 Feb 17. doi: 10.1111/cdoe.12215.

OBJECTIVES: To examine the short-term impact of fluoridation cessation on children’s caries experience measured by tooth surfaces. If there is an adverse short-term effect of cessation, it should be apparent when we focus on smooth tooth surfaces, where fluoride is most likely to have an impact for the age group and time frame considered in this study.

METHODS: We examined data from population-based samples of school children (Grade 2) in two similar cities in the province of Alberta, Canada: Calgary, where cessation occurred in May 2011 and Edmonton where fluoridation remains in place. We analysed change over time (2004/2005 to 2013/2014) in summary data for primary (defs) and permanent (DMFS) teeth for Calgary and Edmonton, for all tooth surfaces and smooth surfaces only. We also considered, for 2013/2014 only, the exposed subsample defined as lifelong residents who reported usually drinking tap water.

RESULTS: We observed, across the full sample, an increase in primary tooth decay (mean defs – all surfaces and smooth surfaces) in both cities, but the magnitude of the increase was greater in Calgary (F-cessation) than in Edmonton (F-continued). For permanent tooth decay, when focusing on smooth surfaces among those affected (those with DMFS>0), we observed a non-significant trend towards an increase in Calgary (F-cessation) that was not apparent in Edmonton (F-continued).

CONCLUSIONS: Trends observed for primary teeth were consistent with an adverse effect of fluoridation cessation on children’s tooth decay, 2.5-3 years post-cessation. Trends for permanent teeth hinted at early indication of an adverse effect. It is important that future data collection efforts in the two cities be undertaken, to permit continued monitoring of these trends.

Korean Fluoride Study Design Inconclusive on Communal Fluoridation

This type of study is typical of those conducted to support fluoride addition to drinking water. But such a study design cannot answer the question as to efficacy and effectiveness of communal fluoridation.  Typically such studies end up concluding what has already been assumed from the beginning.

Kim MJ, Kim HN, Jun EJ, Ha JE, Han DH, Kim JB. Association between estimated fluoride intake and dental caries prevalence among 5-year-old children in Korea. BMC oral health. 2015 Dec 30;15(1):169. doi: 10.1186/s12903-015-0153-0.

BACKGROUND: The purposes of this study were to estimate the fluoride intake from food and drink in 5-year-old Korean children, and to measure the association between estimated fluoride intake and dental caries prevalence.

METHODS: The study involved a secondary analysis of raw data from the 4(th) Korea National Health and Nutrition Examination Survey (KNHANES; 2007-2009). The study subjects were 167 boys and 147 girls aged 5 years who had undergone both physical and nutritional examination as part of the survey. The KNHANES comprised a health questionnaire, a physical examination, and a nutritional examination. The nutritional examination of KNHANES consisted of 3 parts: a dietary life survey, a food-frequency questionnaire, and a food intake investigation. The food intake investigation used the 24-h recall method, with information being provided by the children’s parents. On the basis of this information, we evaluated the fluoride content in a total of 310 food items using the hexamethyldisiloxane (HMDS)-facilitated diffusion method, modified using Taves’ microdiffusion method. As part of the KNHANES survey, oral examinations were conducted at a mobile examination centre by trained dentists using dental mirrors under a fluorescent light. These examinations were performed using methods proposed by the World Health Organization.

RESULTS: The dietary fluoride intake of 5-year-old Korean children was estimated to be 0.35 mg/day, or 0.016 mg/kg/day. The “decayed or filled surfaces” (dfs) indices of primary teeth were higher in children who had a lower dietary intake of fluoride. There was a significant inverse association between dietary fluoride intake and the prevalence of dental caries.

CONCLUSION: The inverse association between dietary fluoride intake levels and prevalence of dental caries implies that the introduction of community caries prevention programmes may be beneficial. Such programmes would include water fluoridation and a fluoride supplementation programme.