Concentration of mercuryin hair of Japanese people

Abstract

This investigation was made to estimate current normal concentrations of total mercury in the hair of Japanese people. Hair samples were collected from 365 healthy volunteers in Tokyo and the surrounding areas from June 1992 to June 1993. Mercury contents in the samples were analyzed by gold amalgam flameless atomic absorption spectrophotometry. The mean of the concentrations of total mercury in the hairs of the males(2.98 ppm,81 volunteers with an average age of 34.7, age 11 to 73) was higher than that of the females(2.02 ppm, 284 volunteers with an average age of 26.5, age 12 to 82). In both the male and female, the mean of the concentrations of total mercury in hair increased with age up to their thirties,then gradually decreased. The concentrations of total mercury in the hair of females at age 18 to 40 showed greater fluctuation, as compared to those of males in the same age groups. In both males and females, the concentration of total mercury in the hair was higher in volunteers who have a preference to fish in their diet than in those who prefer other foods. In both males and females, there was no positive correlation between the total hair mercury and the place of residence of the volunteer although the total hair mercury (2.30 ppm) of male volunteers who inhabit Ibaragi and Chiba, in eastern part of Tokyo, facing the Pacific Ocean or both the Pacific Ocean and Tokyo Bay, was lower than those(3.30 and 3.25 ppm) of male volunteers of other two areas. The mean concentration of total mercury in the hair obtained from all the volunteers was 2.23 ppm, which is considerably lower than that (6.02 ppm) from 73 healthy inhabitants of the same areas in the early 1960's. It is speculated from these results that a major current route for mercury exposure in the Japan is fish consumption.