A new study reveals that women living in coastal areas and in the Northeast U.S. were more likely than other women to have blood mercury (BHg) concentrations exceeding levels of concern, as reported in the January 2009 issue of the peer-reviewed journal Environmental Health Perspectives (EHP).
Women living near coastal areas had 3-4 times greater risk of exceeding acceptable levels of mercury than women living in inland regions.
Analysis of data from the National Health and Nutrition Examination Survey (NHANES) collected between 1999 and 2004 showed that women living in the Northeast were the most likely to have BHg concentrations above 3.5 micrograms per liter, with 19% of women (approximately one in five) affected. Proportions of women with BHg above this level were lower among women in the South, West and Midwest census regions, respectively.
Ethnic and economic patterns in the distribution of blood mercury levels were also evident. Mercury levels were higher among women in an ethnic group that included Asian, Native American, Alaskan, Pacific Island and Caribbean Island women. Also women with higher income levels had an increased risk of higher blood mercury levels. Women with a household income of $75,000 per year or more were more likely to have elevated BHg levels compared with women with household incomes of $55,000 or less.
Average blood mercury levels, mercury intake from fish and shellfish, and total fish consumption were strongly associated. During this period (1999 through 2004) there was no clear time-trend in the average BHg levels, mercury intake or the frequency of fish consumption. However, there was a decline in the proportion of women with high BHg levels over this six-year period. Among these women estimated mercury exposure from seafood decreased, however, their total consumption of fish and shellfish did not show a clear trend over the six-year period. These patterns suggest a shift in the type of seafood consumed.