Biomonitoring of mercury in hair of children living in the Valencian Region (Spain). Exposure and risk assessment.

In this study, we assessed total mercury levels in hair specimens of 661 children, aged 6 to 11, participating in the BIOVAL programme, a human biomonitoring study carried out by the Health Department of the Regional Government of Valencia (Spain). The reference value (95th percentile) determined for this population, within this programme, was 3.25 μg g. Hg concentrations ranged between 0.03 μg g and 8.71 μg g, with a geometric mean of 0.79 (CI 95%: 0.73-0.85) μg g. This mean value was five times higher than the average levels found in children of 17 other European countries (0.145 μg g). About 13% of children had hair mercury levels above the FAO/WHO JECFA guideline of 2.3 μg g and 18% of children had levels above the EFSA health-based guidance value of 1.9 μg. Multiple regression analysis revealed that fish consumption, mother's country of birth (Spain or abroad) and the employment situation of parents were the main predictors of mercury in hair.