Dioxins released from incineration plants and mortality from major diseases: an analysis of statistical data by municipalities.

The aim of this study is to examine the relation between mortality and the existence of incineration plants and dioxin released from the plants in 590 municipalities across Japan. The concentration of dioxins in emissions from incinerators, the amount of dioxins per population, the cumulative amount of dioxins, and the cumulative amount per land area were used as dioxin-related municipal indices. Age-adjusted mortality rates from all causes and five major disease categories by municipality in 1995 were used as health indices. The relation was examined using t-test, analysis of covariance (ANCOVA), correlation coefficients and multiple linear regression analysis, considering the effects of cities' socioeconomic conditions. Although municipalities with plants had significantly higher mortality from female stroke and lower mortality from male cancer at all site and lung than municipalities without plants, these differences were not significant in ANCOVA with socioeconomic indicators. The significant relation between mortality and dioxin indices in correlation coefficient was ruled out when the socioeconomic conditions were adjusted in multiple regression analysis. This study did not show the statistical relation between increased mortality from major causes and the existence of incineration plants and dioxins from the plants at the municipal level.