2006 年 14 巻 p. 121-126
Pollutant discharges per capita were investigated with three statistical methods, 1) three-order regression analysis with Purchase Power Parity based Gross National Income, PPP-GNI, 2) relationship with water, sanitation and economic index (WSEI), a compound index which was introduced by the author, and 3) principle component analysis with first, second and third order of PPP-GNI, rates of access to sanitary facilities and safe drinking water in urban areas and whole countries or areas, and water usage amounts per capita in households. Correlations of BOD discharges per capita with PPP-GNI, and those with WSEI were not clearly observed, which showed the necessity of further considerations of water environmental data and analysis methods, however, it was suggested that the values of BOD discharges per capita could be categorized by regions. Based on the results of the principle component analysis, it was suggested that wastewater facilities deployment in urban areas affected BOD discharge per capita, and increase of the water usage amounts per capita in households should be accompanied with deployment of wastewater treatment facilities.