Application of hair-mercury analysis to determine the impact of a seafood advisory

Following an official recommendation in the Faroe Islands that women should abstain from eating mercury-contaminated pilot whale meat, a survey was carried out to obtain information on dietary habits and hair samples for mercury analysis. A letter was sent to all 1180 women aged 26–30 years who resided within the Faroes, and the women were contacted again 1 year later. A total of 415 women responded to the first letter; the second letter resulted in 145 repeat hair samples and 125 new responses. Questionnaire results showed that Faroese women, on average, consumed whale meat for dinner only once every second month, but the frequency and meal size depended on the availability of whale in the community. The geometric mean hair-mercury concentration at the first survey was higher in districts with available whale than in those without (3.03 vs. 1.88 μg/g; P=0.001). The mercury concentration also depended on the frequency of whale meat dinners and on the consumption of dried whale meat. The 36 women who did not eat whale meat at all had a geometric mean hair-mercury concentration of 1.28 μg/g. At the time of the second survey, the geometric mean had decreased to 1.77 μg/g (P<0.001), although whale was now available in all districts. In comparison with previously published data on hair-mercury concentrations in pregnant Faroese women, these results document substantially lower exposures as well as a further decrease temporally associated with the issue of a stricter dietary advisory.