Methylmercury exposure and mortality in Japan: a life table analysis

The effects on life expectancy from elevated methylmercury (MeHg) exposure were studied in five coastal towns of southern Japan. Hair concentrations of MeHg in the study area were 3 to 6 times higher than the surrounding areas. From 1969-1972 to 1978-1982 life expectancy increased in the study area, with no appreciable difference between that area and the two control areas. When four major causes of death were deleted analytically in both study and control areas, malignant neoplasms contributed the most in recent years to potential gains in life expectancy for both sexes. For the duration of their working ages, however, accidents were the leading contributor for males, followed by malignant neoplasms, heart disease, and cerebrovascular disease. The relative contribution of these causes of death to gain in life expectancy in the study area population is discussed in the context of elevated MeHg exposure.