Fluoride Action Network


Fluoridation of the drinking water is one of the most impactful public health interventions ever done. Dental caries experience importantly decreased in all parts of the world that adopted the intervention. Implementation of fluoridation of the drinking water to populations has always been the focus of criticism, and these discussions often focus on the safety of the intervention. When asked about safety, many people will tend to assume a more cautious position, and the question regarding safety of fluoridation of the drinking water never goes away. Fluoridation of toothpastes also provides the same impact on dental caries experience in populations. It is reasonable to propose that water fluoridation may not be implemented anymore since there is a feasible and effective replacement for it. Finally, this chapter revisits the discussed effects of fluorides on overall health, with particular emphasis on cognition and intelligence.

*Original abstract online at https://www.karger.com/Article/Abstract/520789


… it is not a question of if community water fluoridation should be discontinued, but if it is worth the risk of lowering the IQ of at least certain individuals for an intervention that we have a viable substitute. Fluoridated toothpastes will protect against caries, can be avoided or used in reduced quantities by pregnant women to minimize any exposures, and likely will not have any negative impact on the population intelligence. It is acknowledged that moving from community water fluoridation deserves a deeper reflection on the feasibility of widespread population access to fluoridated toothpastes, its cost-effectiveness, and the effort for implementing and conveying a clear message to the public.


1. Black GV, McKay FS. Mottled teeth. An endemic developmental imperfection of the teeth, heretofore unknown in the literature of dentistry. Dent Cosmos. 1916 Feb;58:129–56.

2. McKay FS, Black GV. An investigation of mottled teeth. Dent Cosmos. 1916 May;58:477–84.

3. Dean HT, Arnold FA Jr, Jay P, Knutson JW. Studies on mass control of dental caries through fluoridation of the public water supply. Public Health Rep. 1950 Oct;65(43):1403–8.

4. Iheozor-Ejiofor Z, Worthington HV, Walsh T, O’Malley L, Clarkson JE, Macey R, et al. Water fluoridation for the prevention of dental caries. Cochrane Database Syst Rev. 2015 Jun;2015(6):CD010856.

5. Rugg-Gunn AJ, Spencer AJ, Whelton HP, Jones C, Beal JF, Castle P, et al. Critique of the review of ‘water fluoridation for prevention of dental caries’ published by the Cochrane Collaboration in 2015. Dr Dent J. 2016 Apr;220(7):335–40.

6. Patil RR. Public Health controversies: Common characteristics. J Glob Infect Dis. 2011 Jan-Mar;3(1):97–8.

7. Carstairs C. Does water fluoridation really damage your children’s IQ? The Conversation. 2019 Nov; https://theconversation.com/does-water-fluoridation-really-damage-your-childrens-iq-123306

8. Kaipio J, Näyhä S, Valtonen V. Fluoride in the drinking water and the geographical variation of coronary heart disease in Finland. Eur J Cardiovasc Prev Rehabil. 2004 Feb;11(1):56–62.

9. Oweis RR, Levy SM, Eichenberger-Gilmore JM, Warren JJ, Burns TL, Janz KF, et al. Fluoride intake and cortical and trabecular bone characteristics in adolescents at age 17: A prospective cohort study. Community Dent Oral Epidemiol. 2018 Dec;46(6):527–34

10. Wasana HMS, Aluthpatabendi D, Kularatne WMTD, Wijekoon P, Weerassoriya R, Bandara J. Drinking water quality and chronic kidney disease of unknown etiology (CKDu): Synergic effects of fluoride, cadmium and harness of water. Environ Geochem Health. 2016 Feb;38(1):157–68.

11. Yang CY, Cheng MF, Tsai SS, Hung CF. Fluoride in drinking water and cancer mortality in Taiwan. Environ Res. 2000 Mar;82(3):189–93.

12. Zohoori FV, Maguire A. Are there good reasons for fluoride labelling of food and drink? Br Dent J. 2018 Feb;224(4):215–7.

13. Deng Q, Yang J, Zhouyang J, Sheng W, Gao S, Zhang Y, et al. Preliminary screening of fluorine-stained osteoblastic apoptosis-related microRNA. Anat Rec (Hoboken). 2021 Jul; Epub ahead of print.

14. Liu H, Gao Y, Sun L, Li M, Li B, Sun D. Assessment of relationship on excess fluoride intake from drinking water and carotid atherosclerosis development in adults in fluoride endemic areas, China. Int J Hyg Environ Health. 2014 Mar;217(2–3):413–20.

15. Liang C, Ji R, Cao J, Cheng X. Research on the relationship between populations’ long-term exposure to fluoride in drinking water and bone fracture in China. Wei Sheng Yan Jiu. 2001 Sep;30(5):287–93.

16. Zhang LE, Huang D, Yang J, Wei X, Qin J, Ou S, Zhang Z, Zou Y. Probabilistic risk assessment of Chinese residents’ exposure to fluoride in improved drinking water in endemic fluorosis areas. Environ Pollut. 2017 Mar;222:118–25.

17. Sezgin BI, Onur SG, Mentes? A, Okutan AE, Haznedarog?lu E, Vieira AR. Two-fold excess of fluoride in the drinking water has no obviou health effects other than dental fluorosis. J Trace Elem Med Biol. 2018 Dec;50:216–22.

18. Peckham S. Slaying sacred cows: Is it time to pull the plug on water fluoridation? 2021 Jun;22(2):159–77.

19. Cury JA, Tenuta LMA, Ribeiro CCC, Leme AFP. The importance of fluoride dentifrices to the current dental caries prevalence in Brazil. Braz Dent J. 2004 Feb;15(3):167–74.

20. Grandjean P. Developmental fluoride neurotoxicity: An updated review. Environ Health. 2019 Dec;18(1):110.

21. Sherlin DMG, Verma RJ. Vitamin D ameliorates fluoride-induced embryotoxicity in pregnant rats. Neurotoxicol Teratol. 2001 Mar-Apr;23(2):197–201.

22. Wang J, Ge Y, Ning H, Wang S. Effects of high fluoride and low iodine on biochemical indexes of the brain and learning-memory of offspring rats. Fluoride. 2004 Aug;3737(3):201–8.

23. Liu F, Ma J, Zhang H, Liu P, Liu Y-P, Xing B, Dang Y-H. Fluoride exposure during development affects both cognition and emotion in mice. Physiol Behav. 2014 Jan;124:1–7.

24. Yang L, Jin P, Wang X, Zhou Q, Lin X, Xi S. Fluoride activates microglia, secretes inflammatory factors and influences synaptic plasticity in the hippocampus of rats. Neurotoxicology. 2018 Dec;69:108–20.

25. Wen D, Zhang F, Zhang E, Wang C, Han S, Zheng Y. Arsenic, fluoride and iodine in groundwater of China. J Geochem Explor. 2013 Dec;135:1–21

26. Wang S-X, Wang Z-H, Cheng X-T, Li J, Sang Z-P, Zhang X-D, et al. Arsenic and fluoride exposure in drinking water” children’s IQ and growth in Shanyin county, Shanxi province, China. Environ Health Perspect. 2007 Apr;115(4):643–7.

27. Seraj B, Shahrabi M, Shadfar M, Ahmadi R, Fallahzadeh M, Eslamlu HF, et al. Effect of high water fluoride concentration on the intellectual development of children in Makko/Iran. J Dent (Tehran). 2012 Summer;9(3):221–9.

28. Sebastian ST, Sunitha S. A cross-sectional study to assess the intelligence quotient (IQ) of school going children aged 10–12 years in villages of Mysore district, India with different levels. J Indian Soc Pedod Prev Dent. 2015 Oct–Dec;33(4):307–11.

29. Rocha-Amador D, Navarro ME, Carrizales L, Morales R, Calderón J. Decreased intelligence in children and exposure to fluoride and arsenic in drinking water. Cad Saude Publica. 2007;23(Suppl 4):S579–87.

30. Grandjean P. Developmental fluoride neurotoxicity: An updated review. Environ Health. 2019 Dec;18(1):110.

31. American Dental Association. Fluoride: Topical and systemic supplements. https://www.ada.org/en/member-center/oral-health-topics/fluoride-topical-and-systemic-supplements [retrieved September 3, 2021.

32.Bashash M, Thomas D, Hu H, Martinez-Mier EA, Sanchez BN, Basu N, et al. Prenatal fluoride exposure and cognitive outcomes in children at 4 and 6–12 years of age in Mexico. Environ Health Perspect. 2017 Sep;125(9):097017.

33. Green R, Till C, Cantoral A, Lanphear B, Martinez-Mier EA, Ayotte P, et al. Associations between urinary, dietary, and water fluoride concentrations among children in Mexico and Canada. Toxics. 2020 Nov;8(4):110.

34. Green R, Lanphear B, Hornung R, Flora David, Martinez-Mier EA, Neufeld R, et al. Association between maternal fluoride exposure during pregnancy and IQ scores in offspring in Canada. JAMA Pediatr. 2019 Aug;173(10):940–8.

35. Till C, Green R, Flora D, Hornung R, Martinez-Mier EA, Blazer M, et al. Fluoride exposure from infant formula and child IQ in a Canadian birth cohort. Environ Int. 2020 Jan;134:105315.

36. Till C, Green R, Grundy JG, Hornung R, Neufeld R, Martinez-Mier EA, et al. Community water fluoridation and urinary fluoride concentrations in a national sample of pregnant women in Canada. Environ Health Perspect. 2018 Oct;126(10):107001.

37. Cunningham JEA, McCague H, Malin AJ, Flora D, Till C. Fluoride exposure and duration and quality of sleep in a Canadian population-based sample. Environ Health. 2021 Feb; 20(1):16.

38. Malin AJ, Riddell J, McCague H, Till C. Fluoride exposure and thyroid function among adults living in Canada: Effect modification by iodine status. Environ Int. 2018 Dec;121(Pt 1):667–74

39. Xu K, An N, Huang H, Duan L, Ma J, Ding J, et al. Fluoride exposure and intelligence in school-age children: Evidence from different windows of exposure susceptibility. BMC Public Health. 2020 Nov;20:1657.

40. Canadian Agency for Drugs and Technologies in Health. Community water fluoridation exposure: A review of neurological and cognitive effects – a 2020 update. CADTH Rapid Response Report: Summary with Critical Appraisal. Ottawa: CADTH; 2020 Nov.

41. Zhang S, Zhang X, Liu H, Qu W, Guab Z, Zeng Q, et al. Modifying effect of COMT gene polymorphism and a predictive role for proteomics analysis in children’s intelligence in endemic fluorosis are in Tianjin, China. Toxicol Sci. 2015 Apr;144(2):238–45.

42.Cui Y, Zhang B, Ma J, Wang Y, Zhao L, Hou C, et al. Dopamine receptor D2 gene polymorphism, urine fluoride, and intelligence impairment of children in China: A school-based cross-sectional study. Ecotoxicol Environ Saf. 2018 Dec;165:270–7.

43. Zhao L, Yu C, Lv J, Cui Y, Wang Y, Hou C, et al. Fluoride exposure, dopamine relative gene polymorphism and intelligence: A cross-sectional study in China. Ecotoxicol Environ Saf. 2021 Feb;209:111826.

44. McLaren L, Patterson SK, Faris P, Chen G, Thawer S, Figueiredo R, et al. Fluoridation cessation and children’s dental caries: A 7-year follow-up evaluation of grade 2 schoolchildren in Calgary and Edmonton, Canada. Community Dent Oral Epidemiol. 2021 Jul 26. doi: 10.1111/cdoe.12685. Online ahead of print.

45. Christakis DA. Decision to publish study on maternal fluoride exposure during pregnancy. JAMA Pediatr. 2019 Aug;173(10):948.

46. Aghaji QN, Nwabuo CC. Association between maternal fluoride exposure and child IQ. JAMA Pediatr. 2020 Feb;174(2):210–1.

47. Waugh D. Association between maternal fluoride exposure and child IQ. JAMA Pediatr. 2020 Feb;174(2):211–2.

48. Berezow AB. Association between maternal fluoride exposure and child IQ. JAMA Pediatr. 2020 Feb;174(2):212.

49. Gong CX, James NE. Association between maternal fluoride exposure and child IQ. JAMA Pediatr. 2020 Feb;174(2):212–3.

50. Bledsoe J, Breiger D, McKeever J. Association between maternal fluoride exposure and child IQ. JAMA Pediatr. 2020 Feb;174(2):213.

51. Ritchie SJ, Morris AJ, McConway K. Association between maternal fluoride exposure and child IQ. JAMA Pediatr. 2020 Feb;174(2):213–4.

52. Farrow S, Joffe AR. Association between maternal fluoride exposure and child IQ. JAMA Pediatr. 2020 Feb;174(2):214.

53. Gehani CP, Pollick H, Stevenson RA. Association between maternal fluoride exposure and child IQ. JAMA Pediatr. 2020 Feb;174(2):214–5.

54. Howard CV, Micklem HS, Neurath C. Association between maternal fluoride exposure and child IQ. JAMA Pediatr. 2020 Feb;174(2):215.

55. Epidemiology is a science of high importance. Nat Commun. 2018 May;9(1):1703.