2006 Volume 19 Issue 2 Pages 81-88
Benzene concentration in some regions has not yet attained the atmospheric standard regulated in 1997. Although the exhaust gas from the vehicles is considered to be the main source of benzene, the emission factor of vehicles that are actually running has not been evaluated correctly. Assuming that the ratio of the emission amount of nitrogen oxide to the emission amount of benzene is equivalent to the ratio of nitrogen oxide concentration to benzene concentration, the emission factors of gasoline car and diesel car were estimated as 12.3mg/km and 13.0mg/km, respectively at Shijonawate roadside monitoring station. Benzene concentration around this station was calculated by a numerical model with a simple building configuration and it could be reproduced comparatively well. Benzene concentration around Uchide roadside monitoring station, where the Hanshin. Expressway exists, was also calculated using the same technique. This result also correctly reproduced the observation concentration. It was suggested that the benzene concentration near the road can be presumed by the numerical model with a simple building geometry .
