Pregnant women may get too much mercury by following U.S. seafood advice

Pregnant women who follow government seafood recommendations may be exposing their babies to too much toxic mercury, according to a new report from the Environmental Working Group (EWG). The study also found that women may not be getting enough healthy omega-3 fatty acids from the fish they choose. The authors call for guidelines to be more specific about which fish are healthiest.

The report was released March 16, 2016.

EWG tested hair samples from 254 women who eat two or more seafood meals per week, which is in line with federal recommendations. The samples were analyzed by students from Harvard T.H. Chan School of Public Health, who found that nearly 30% of the women exceeded safety guidelines for mercury exposure during pregnancy, and 60% were not getting enough of the healthy fats essential for fetal development.

Salmon, sardines, and rainbow trout are among the fish considered healthy choices according to EWG recommendations, because they are high in omega-3 and low in mercury.

Philippe Grandjean, an adjunct professor of environmental health at Harvard Chan, oversaw the student researchers.