Level of fluoride and arsenic in household shallow well water in Wamiao and Xinhuai villages in Jiangsu Province, China

Abstract

After previously excluding iodine and lead as confounding factors, the aim of the present study, conducted in June 2013, was to consider whether arsenic was a confounding factor in the studies of children’s intelligence in Wamiao and Xinhuai. Fluoride and arsenic levels were measured in water samples from the 37 household shallow wells still in use for providing water for washing but not drinking, 17 in Wamiao and 20 in Xinhuai. The fluoride levels in the household shallow wells in Wamiao (2.28±0.44 mg/L, range: 1.66–3.18 mg/L) were significantly higher than those in Xinhuai (0.38±0.21 mg/L, range: 0.15–0.77 mg/L) (t=17.08, p=0.000). In contrast, the levels of arsenic in Xinhuai (16.40±19.11 ug/L, range: 0–48.50 ug/L) were significantly higher than those in Wamiao (0.24±0.26 ug/L, range: 0–0.50 ug/L) (t=3.48, p=0.001). In our 2003 study, in high-fluoride Wamiao (mean drinking water F=2.47 mg/L) the average IQ was 8.4 points lower (92.02 vs. 100.41) than in the low-fluoride Xinhuai (mean drinking water F=0.36 mg/L). These results make it very unlikely that the differences in IQ of the children living in Wamiao and Xinhuai are the result of differences in exposure to arsenic rather than to fluoride.