Compilation and application of a primary PM2.5 emissions inventory with high sectoral resolution in Japan

To elucidate the macro-structure of the PM2.5 emissions generated by Japanʹs economic activities, this paper presents an emission inventory of primary particles of PM2.5 with high sectoral resolution based on the Japanese Input–Output Tables, comprising some 400 sectors. These primary PM2.5 emissions were estimated by multiplying the estimated energy consumption associated with each fuel type by a PM10 emission factor incorporating the technological level of dust collection in each sector and the mass ratio of PM2.5 to PM10. Non-energy emissions from agricultural open burning were also determined. Total PM2.5 emissions in 2000 were 252 kt, 49% of which were due to mobile emission sources. Changes in total PM2.5 emissions between 1990 and 2000 were also calculated. This showed that a substantial increase in energy sector emissions due to rising coal consumption was offset by a sharp decline in emissions from road vehicles and shipping vessels, resulting in an overall decrease in total emissions. In addition, the emissions induced by economic demand in each sector were quantified by means of input–output analysis, which revealed that demand for construction, foods and communications and services constituted the principal causes of real domestic emissions. An assessment of sectoral contributions to PM2.5 emissions that takes into account the effects of human exposure, expressed as external costs, suggests that the contribution of transportation is greater than indicated on the grounds of direct emissions alone.