Relationship between Mercury Content of Hair and Amount of Fish Consumed

Purpose of the study was to clarify the relationship between the amount of mercury in scalp hair and the amount of seafood consumed. The study was based on two premises. 1. The amount of mercury in scalp hair will increase according to intake of methylmercury from marine products. 2. The amount of mercury in hair of groups of persons who have different religious or dietary customs concerning consumption of marine products will also differ. Mercury in the scalp hair of 178 residents of Fukuoka, Japan, was measured. They had had no abnormal exposure to occupational sources, medicines, pesticides, cosmetics, and other suspected sources of mercury contamination. The mean mercury content in hair samples of 111 males was 4.35 p.p.m. with a standard deviation (S.D.) of 2.45 p.p.m. For 67 females the average amount of mercury was 3.94 p.p.m., S.D. 2.03 p.p.m. The Fukuoka residents ate about an average amount of fish for Japanese, 84 grams per day. The average mercury content in 89 hair samples of male Ikitsuki islanders (mostly fishermen working for a tuna fishing company) was 4.83 p.p.m. with an S.D. of 2.31 p.p.m. The amount of mercury apparently increased with age; no such increase was apparent among the Fukuoka residents. The amount of mercury in the scalp hair of 14 American men living in Japan was 1.89 p.p.m. with 1.04 p.p.m. S.D. Mercury content of samples from seven Americans in Cleveland, Ohio, was, for three males, 2.41 p.p.m. (S.D. 132 p.p.m.) and for four females, 1.61 p.p.m. (S.D. 0.32 p.p.m.). Hair samples from Nepalese living in Silgarhi Doti and Dhangarhi were collected and measured. The average amount for 31 males was 0.163 p.p.m. with 0.187 p.p.m. S.D., and that for 14 females was 0.457 p.p.m. with 0.484 p.p.m. S.D. They ate no fish during the survey period. The amount of methylmercury in the samples was 57 percent of the total mercury content.