Serum Fluoride Level and Children's Intelligence Quotient in Two Villages in China
http://ehp03.niehs.nih.gov/article/fetchArticle.action;jsessionid=F0787068E7DA57D46BBBF7D712A3209F?articleURI=info%3Adoi%2F10.1289%2Fehp.1003171#top
http://ehp03.niehs.nih.gov/article/fetchArticle.action;jsessionid=F0787068E7DA57D46BBBF7D712A3209F?articleURI=info%3Adoi%2F10.1289%2Fehp.1003171#top
Xiang Q, Liang Y, Chen B 2010. Serum Fluoride Level and Children's Intelligence Quotient in Two Villages in China. Environ Health Perspect :-. doi:10.1289/ehp.1003171
Abstract
Background: Animal studies show that brain fluoride levels increase with increasing exposure to fluoride. Human studies have indicated an association between high levels of drinking-water fluoride and lower intelligence. Data on the association between serum fluoride and children's intelligence quotient (IQ) are limited.
Objective: This study was conducted to assess the relationship between serum fluoride and children's IQ.
Methods: We collected blood samples from 512 children aged 8-13 years from two villages (Wamiao and Xinhuai) in China. We also used minitype fluoride ion selective electrode and Combined Raven's Test for Rural China (CRT-RC) to measure serum fluoride and children's IQ.
Results: In Wamiao, the mean (± SD) concentration of fluoride in serum was 0.081± 0.019 mg/L, and average children's IQ was 92.02 ± 13.00; in Xinhuai, fluoride concentration was 0.041 ± 0.009 mg/L and average IQ was 100.41 ± 13.21. The regression coefficients between serum fluoride and children's IQ were –0.163 (p = 0.015) in Wiamiao, and 0.054 (p = 0.362) in Xinhuai. Serum fluoride levels were negatively associated with IQ after adjusted for age and sex, the ORs for IQ < 80 across groups with serum fluoride measuring < 0.05, 0.05–0.08, > 0.08 mg/L were 1, 2.22 (95% confidence interval: 1.42–3.47), and 2.48 (95% confidence interval: 1.85–3.32) (p for trend < 0.001) respectively. IQ was not related to family income and parent's education level. There was a significant positive relation between serum fluoride and drinking-water fluoride.
Conclusions: The results indicated that fluoride in drinking water was highly correlated with serum fluoride, and higher fluoride exposure may affect intelligence among children.
