The alternative health community is at it again, once more spreading fear and misinformation regarding the effects of water fluoridation and the use of dental fluoride. In a post title “Fluoride Lowers Your IQ | A Debated Truth?“, Mike Barret of Natural Society cites a 2010 study titled “Serum Fluoride Level and Children’s Intelligence Quotient in Two Villages in China” to argue that the “great deal of controversy revolving around the addition of fluoride in many communities’ drinking water” is based on demonstrable health concerns. I’ve dealt with Natural Society before and once again the current study being cited does not actually support the claim being made. Citing studies done on the health dangers of high levels of naturally occurring fluoride in groundwater, exposure to industrial pollution, and occupational fluoride exposure as evidence against the controlled use of dental fluoride and water fluoridation programs is a common tactic among anti-fluoridationists. I have long maintained that whenever possible, one should read the original study. The study cited by Barret involved 512 children from two villages, Wamiao and Xinhuai, in China. The authors of the study describe the villages,
Wamiao and Xinhuai are located 64 km apart in Sihong County. Wamiao village, in northeast Sihong County, about 32 km northeast of Sihong, is a severe endemic fluorosis area. The mean fluoride level in Wamaio drinking water was 2.47 ± 0.79 mg/L (range 0.57–4.50 mg/L), and the prevalence of dental fluorosis and defected dental fluorosis was 88.56% and 38.98%, respectively. Xinhuai village, in the southwest part of Sihong county, about 32 km southwest of Sihong, is a non endemic fluorosis area. The mean level of fluoride in Xinhuai drinking water was 0.36±0.15 mg/L (range 0.18-0.76 mg/L), and the prevalence of dental fluorosis was 4.48%, with no cases of defected dental fluorosis identified (Xiang et al. 2004, National Standard of P.R. China 1997).
In the study children in Wamiao were found to have lower IQ scores and higher serum fluoride levels than children in Xinhuai. In Xinhua 27.59% scored in the >110 range indicating “high intelligence”, 51.72% of children scored in the 90-109 or “normal range”, and another 6.2% in the <79 range, this is compared to only 8.11% of children from Wamiao scoring in the >110 range, 47.30% in the 90-109 range, and 15.31% in the <79 range. The authors came to the conclusion that the difference in fluoride exposure is responsible for the differing IQ scores after accounting for various factors. Take notice of the levels of fluoride reported for each village. Wamiao, where lower IQ scores were reported, had levels that ranged from 0.57–4.50 mg/L which on the high end exceeds the current Environmental Protection Agency’s enforceable guideline (4.0 mg/L) for fluoride in groundwater and is double the secondary guideline (2.0 mg/L) meant to protect children. However the village of Xinhuai, where IQ scores were higher, had levels of 0.18-0.76 mg/L which is actually quite close to the Department of Health and Human Service’s current standard (0.7 mg/L) for community water fluoridation and is below both the EPA’s enforceable and secondary guidelines. Both the DHHS and EPA’s guidelines are evidence-based, in general reflecting the current scientific literature and consensus, and they are amicable to review and revision. This is a great example of science in action. Rather than providing evidence that community water fluoridation is dangerous, this study actually is in line with the current guidelines and regulations. There is always room for more science, but continuing to the repeat the same canards over and over while crying “SHILL” & “CONSPIRACY!” at any dissent is not advancing science.
Fluoride & Brain Damage
Fluoride & Heart Disease?
Fluoride & the Brain: Strike 3, You’re Out!
Fluoride & the Brain: The China Studies
Community Water Fluoridation: Guidelines and Recommendations
Your community’s fluoridation level can be seen at My Water’s Fluoride
 I will not delve into the issues surrounding IQ testing at this moment but I will direct my readers here for a introduction to the controversy