Methylmercury monitoring study in Karakuwacho peninsula area in Japan

Methylmercury (MeHg) is a worldwide concern owing to its adverse health effects. To explore MeHg exposure burdens and the potential contributing factors in different subpopulations in a peninsula area (Karakuwacho) in Japan, a cross-sectional survey was performed. This study included 189 individuals from 102 families. The geometric means of total hair mercury (THg) were 5.74, 3.78 and 2.37 μg/g for adult males, females and children, respectively, of which 56.5 %, 30.9 % and 12.9 % had hair THg exceeding 5 μg/g, respectively. Tuna and mackerel were the common fish species that were positively correlated with hair THg levels in different subpopulations (standardized coefficient ranged from 0.20 to 0.58, p < 0.05). Frequent consumption of these fish species and a large amount of fish intake are likely major contributors of MeHg exposure in this area. Local-scale risk evaluation and risk communication should be highlighted in future studies.