Connection between NO(x) and SO(x) collected from the Japanese cedar tree and Pollinosis

In this study, substances of air pollution (NO3-, SO4(2-)) which were collected from the surface of the Japanese cedar flowering parts and pollens in one mountainous and two urban areas were measured by ion chromatography monthly from November '87 to March of '88 and '90 to '91. A questionnaire study of nasal symptoms and school physical examinations were performed on about 400 junior high schools students in two districts (urban area and mountainous area) in March '87 and '91. The results of this research are as follows: i) The quantity of NO4 collected from the pollen of Japanese cedars in the urban and municipal park areas was 2.0 and 3.0 times greater, respectively, than in the mountainous area. The respective concentrations of SO2- were 5 and 2 times higher than the concentration in the mountainous area. ii) The results of a questionnaire of nasal symptoms and of the physical examinations at two junior high schools in the different districts showed a lower incidence of pollinosis in the mountainous area than in the urban area. Comparatively, the percentage of pollinosis in the mountainous area rose from 17.0% in 1987 to 25.0% in 1991, corresponding to a similar rise in the number of diesel vehicles running in the area.