Influence of socio-demographic and diet determinants on the levels of mercury in preschool children from a Mediterranean island

- 20% of children exceed the WHO guideline level of 2 μg/g of mercury in hair.
- Higher mercury concentrations in female than male children are observed.
- Oily fish is the main source of mercury within frequent-fish consumer children.
- Higher parity is associated with lower mercury concentrations in children.
- No associations between children's cognitive abilities and mercury levels are found.

Mercury levels measured in 302 hair samples of 4 year-old children from Menorca (western Mediterranean Sea) are reported. Their concentrations, arithmetic mean 1.4 μg/g, ranging between 0.040 μg/g and 10 μg/g, were higher than in other children inland populations but lower than in previously studied island cohorts, e.g. Faroe, Madeira and Seychelles. 20% of the samples were above the WHO recommended values. Higher concentrations in females than males were observed. Frequent consumption of fish and other seafood were significantly related to the observed mercury concentrations. Oily fish was the main source of this pollutant but shellfish and squid consumption were also associated with high mercury concentrations. Maternal smoking, occupational status or previous siblings were also found to significantly influence the levels of this pollutant. McCarthy Scales of Children's Abilities used to assess children's motor and cognitive abilities did not show association with mercury concentrations at 4 years of age.