Hair Mercury Levels and Their Relationship with Seafood Consumption among Preschool Children in Shanghai.

Mercury is a global pollutant. Children are vulnerable to environmental toxicants. Seafood consumption is a major source of methylmercury exposure. In order to ascertain children's mercury exposure levels and study their relationship with seafood consumption, we conducted a cross-sectional study among preschool children in Shanghai. According to our data, the geometric mean of the mercury levels in children's hair was 191.9 (95% CI: 181.8, 202.4) μg/kg. These results indicate that high income may be a predictor of elevated mercury levels in children's hair. Intake of marine fish, especially tuna and pomfret, was documented in our study and found to increase the risk of high mercury levels. Frequency of fish consumption was positively related with hair mercury levels. Our study is the first to provide baseline data for hair mercury concentration among preschool children in Shanghai.