Spatially differentiated impact assessment methodology-A comparative study of impacts of electric vehicle and gasoline vehicle during the usage in Tokyo Metropolitan area.

Abstract

There have been attempts to reflect the site-dependency of the impacts of air emissions in life cycle impact assessment (LCIA). Recently, EXPEC (Exposure Per Emission Coefficient) has been proposed as a useful tool for assessing spatially differentiated potential impacts. In this study, EXPEC was applied to estimate the spatially differentiated potential impacts caused by direct emissions from gasoline vehicle (GV) and indirect emissions from electric vehicle (EV) during the usage (100, 000km) of vehicles in Tokyo Metropolitan area. We focused on NOx emissions as an example of pollutants. A simplified circle Gaussian plume model was used to calculate concentration of NOx around emission source. The total amount of NOx inhaled by the local population was calculated with the concentration and population densities around the emission sources, and traffic volume in Tokyo Metropolitan area. The total amounts of NOx inhaled by the local population caused by GV and EV during the usage (100, 000km) of vehicles were 8.7-9.6 10-3kg and 3.7 10-6kg, respectively. Significant difference between EV and GV was observed in the total amount of NOx inhaled by the local population. It is suggested that site-specific consideration is quite important to assess the actual impacts by vehicles.