メチル水銀濃厚汚染地域住民の死亡構造

抄録

In order to investigate the health effects of exposure to methylmercury, a mortality study was carried out by means of standardized mortality ratio (SMR) in the most prevalent area with Minamata disease for the period 1970-81. Information on death (216 males and 196 females) was available from the population registry which had been kept in Minamata City municipal office since 1970. All but one certificates of death (follow-up rate 99.8%) on these subjects were collected through the district legal affairs bureau. The SMRs for cancer of the liver and chronic liver diseases were significantly higher, at least 5% level, in the most prevalent area than in Minamata City, but all causes of death were not significantly different. High SMRs for cancer of the liver and chronic liver diseases are consistent with the results from the mortality analysis of Minamata disease patients. It was emphasized that this issue should be further investigated by taking into account the related multiple risk factors to liver cancer and chronic liver diseases including liver cirrhosis.