Estimated intake levels of methylmercury in children, childbearing age and pregnant women in a Mediterranean region, Murcia, Spain.

Methylmercury (MeHg) is a bioaccumulable toxin in the trophic chain and a powerful neurotoxin during fetal and child development. Consumption of contaminated fish and shellfish is a principal environmental source of MeHg exposure. This study was designed to assess the Hg and estimated MeHg intake in vulnerable groups of the Murcia region, a Mediterranean part of Spain, compared with international regulations. A validated food frequency questionnaire was used to assess seafood consumptions in 320 children younger than 10 years, 301 women of childbearing age, and 537 pregnant women. Hg concentrations were measured in the most consumed fish products by cold vapor generation-atomic fluorescence spectrometry. The weekly intake of MeHg (microg/kg bw/week) was 2.60 (95% CI = 2.10-3.10) in children 1-5 years, 2.65 (95% CI = 2.26-3.03) in children 6-10 years, 0.98 (95% CI = 0.89-1.07) in women of childbearing age, and 0.88 (95% CI = 0.81-0.95) in pregnant women. The main exposure to MeHg, especially in young children, is related to intake of bluefin tuna and swordfish. Fifty-four percent of children aged 1-10 years, 10% of pregnant women, and 15% of women of childbearing age exceed the Joint Expert Committee on Food Additives provisional tolerable weekly intake of MeHg. In the Murcia region, where fish is a central component of the diet, the focus should be on educating vulnerable populations to reorient fish consumption in order to lower the amount of Hg incorporated with the diet as well as to reduce Hg emissions into the environment.