Chemical composition of atmospheric aerosols in the general environment and around a trunk road in the Tokyo metropolitan area

Abstract To evaluate the influence of vehicle exhaust particles on the urban atmosphere, atmospheric aerosols collected in the general environment and at a trunk road sampling site in the Tokyo metropolitan area were analyzed for carbonaceous and ionic components. Samples were collected as fine ( −3 , and it was accounted for 68% of the difference of the mass concentration. The mass concentration reconstructed by the mass closure model using element analysis results corresponded more closely to the observed mass concentration in the general environment samples than in the roadside samples. It is suggested that the contribution of the organic compounds in the roadside particles was underestimated. Diesel vehicle emission control regulations implemented in October 2003 seem to have had an effect because there was a significant difference in the average concentration of suspended particulate matter and NO x before and after implementation of the regulations. Moreover, the EC/TC ratio has been decreasing over time.