Abstract
The suspended particulates including tar, benzo (a) pyrene (BaP) and other polycyclic hydrocarbons (hydrocarbon) and metals in Osaka City were analysed and compared by localisation as commercial and industrial area, during 1967-1974. Further determinations were performed about some hydrocarbons from automobile exhaust or different factories.
The results were as follows.
1) Suspended particulates, BaP and metals have been reduced after 1970, and pollution level has become similar in commercial and industrial area. The concentration of BaP was generally greater in winter than in summer.
2) The respirable particulate (smaller than about 7μ) was found, as 56-60 % of the total particulate, the tar was 81-91 %, the BaP and other hydrocarbons were 89-91 %, and the metals were Cd 80 %, Cu 70 %, Pb, Cr 60 % and Ni 45 %, respectively. BaP or other hydrocarbons and almost metals in the respirable particulates had good correlations with each other.
3) The ratio of each hydrocarbons to BaP in ambient air near a busy main road were higher percentage than these of urban atmosphere, and in the ambient air of different factories were higher than urban atmosphere except coronene. The ratios of coronene to BaP were suggested as posible indicator of source composition.
