Tag Archives: fluoridation

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.

Fluoride Advocacy Misguided, Unsupported, Unnecessary

Studies such as the one below rely on several assumptions. Addition of fluoride to drinking water is presumed to be necessary to prevent dental caries. Further, advocates and review panels continue to push the idea that an “optimum dose” to drinking water exists. Despite the claims made here the idea that an optimum drinking water dose to a population exists is a default assumption. Time to move on….

Spencer AJ, Do LG. Caution needed in altering the ‘optimum’ fluoride concentration in drinking water. Community Dentistry and Oral Epidemiology. 2015 Dec 29. doi: 10.1111/cdoe.12205.

The US Public Health Service has finalized its recommendation relating to community water fluoridation (Federal Panel on Community Water Fluoridation, US Department of Health and Human Services, 2015). It recommends an optimal concentration of 0.7 mg/l F based on their argument that this concentration provides the best balance of protection from dental caries while limiting the risk of dental fluorosis. The rationale for this recommendation can be questioned, particularly given the contrasting etiologies and impact on the community. Uncertainty surrounds the key evidence considered by the panel. This study argues that the panel should have exercised more caution and called for further research before reducing the ‘optimal’ concentration of fluoride in water supplies. Up-to-date data on caries and fluorosis trend by age group or birth cohort, analyses on attributable risk for fluorosis, data on individual and population impact of caries and fluorosis, water intake over an extended period across the seasons, and the curvilinear relationship of fluoride concentration in water supplies and caries protection would have all been desirable to inform the panel, given the foreshadowing of the recommendation in late 2011. Further, a wider range of policy directions to achieve the best balance of protection from dental caries while limiting the risk of dental fluorosis are available from the international literature. Assessment of these should have been more evident. There is a public health policy responsibility to monitor water fluoridation programs so as to achieve a near maximum reduction in dental caries without unacceptable levels of dental fluorosis. However, recommendations to alter existing policy need to be cognizant of the balancing of risk and protective exposures across the entire population and potentially all ages and to be based on recent data that are purposefully collected, critically analyzed and carefully interpreted.

Communal Drinking Water Fluoridation Should be Abandoned Globally, Alternatives Pursued

Peckham S, Awofeso N. Water fluoridation: a critical review of the physiological effects of ingested fluoride as a public health intervention. The Scientific World Journal. 2014 Feb 26;2014:293019. doi: 10.1155/2014/293019.

Fluorine is the world’s 13th most abundant element and constitutes 0.08% of the Earth crust. It has the highest electronegativity of all elements. Fluoride is widely distributed in the environment, occurring in the air, soils, rocks, and water. Although fluoride is used industrially in a fluorine compound, the manufacture of ceramics, pesticides, aerosol propellants, refrigerants, glassware, and Teflon cookware, it is a generally unwanted byproduct of aluminium, fertilizer, and iron ore manufacture. The medicinal use of fluorides for the prevention of dental caries began in January 1945 when community water supplies in Grand Rapids, United States, were fluoridated to a level of 1 ppm as a dental caries prevention measure. However, water fluoridation remains a controversial public health measure. This paper reviews the human health effects of fluoride. The authors conclude that available evidence suggests that fluoride has a potential to cause major adverse human health problems, while having only a modest dental caries prevention effect. As part of efforts to reduce hazardous fluoride ingestion, the practice of artificial water fluoridation should be reconsidered globally, while industrial safety measures need to be tightened in order to reduce unethical discharge of fluoride compounds into the environment. Public health approaches for global dental caries reduction that do not involve systemic ingestion of fluoride are urgently needed.