Study tells where and who have the US's highest mercury levels.

Sep 25, 2008

Mahaffey KR, RP Clickner and RA Jeffries. 2008. Adult women’s blood mercury concentrations vary regionally in USA: Association with patterns of fish consumption (NHANES 1999-2004). Environmental Health Perspectives doi:10.1289/ehp.11674.

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Synopsis by Carys L. Mitchelmore

Women's blood mercury levels are decreasing overall in the US, but differences still persist regionally, ethnically and economically. Women still are eating fish, but appear to be shifting to species that are less contaminated.

A recent study provides for the first time estimates of blood mercury distribution in US women and of regional fish consumption for coastal and non-coastal populations.

Blood mercury levels in women were associated with where they live, their ethnicity and their income levels, report the researchers who analyzed data gathered by the CDC.

Higher levels of blood mercury were more common in women living in coastal areas of the USA, with higher exposures in the Northeast region. Increased levels were found in groups that ate more fish, including among Asian women and higher income women.

Blood mercury levels over the time of the study (1999-2004) decreased. The decline is thought to be due to a shift in the choice of fish species eaten as fish consumption has not gone down.

This study focuses on mercury blood levels in women of child-bearing age because of the potential risk of brain damage, learning problems and other mercury-associated health effects in children who are exposed before birth to methylmercury.