Biomonitoring of mercury in hair of breastfeeding mothers living in the Valencian Region (Spain). Levels and predictors of exposure

- Total mercury in hair was determined in 120 samples from breastfeeding women.
- The geometric mean of Hg in hair was of 1.22 μg g−1.
- Mercury concentration in hair was 6 times higher than in other European studies.
- 27% of mothers exceed the EFSA health guidance value of 1.9 μg g−1.
- Older age, smoking and high fish consumption were the major predictors of mercury in hair.

This study focused on the evaluation of the levels of total mercury in hair among 120 breastfeeding mothers aged 20 to 45 -. The concentrations of Hg ranged from 0.07 to 6.87 μg/g with a geometric mean (GM) of 1.22 μg/g. This GM is six times higher than the average internal exposure of mothers from other 17 European countries (0.225 μg/g). Near 70% of mothers presented levels of Hg above the USA EPA internal exposure guideline of 1 μg/g, and 27% exceeded the EFSA health-based guidance value of 1.9 μg/g. The multivariate regression analysis revealed that age, smoking and fish consumption (sword fish, small fat fish, small lean fish) were the major predictors of mercury in hair.