During the summer of 1975, effects of photochemical oxidants and other factors on health of schoolchildren and students were investigated in Saitama Prefecture, northern suburbs of Tokyo metropolitan area. The levels of each air pollutant and meteorological foctor were divided to 4, 5, 6 or 8 ranks and ratios of ones who had acute complaints to person days were compared with each other.
Oxidant concentration most closely related to the ratio. The incidences stepwise increased from 0.02% to 0.3%, 3% in accordance with the elevation of oxidants levels (-0.07 ppm, 0.12-0.19 ppm, 0.20 ppm-). The levels of SO2, NO2, SPM and visibility related to the incidences to some extent. When SO2, NO2 and SPM levels exceeded 0.07 ppm, 0.10 ppm and 0.2 mg/m3 respectively and visibility lowered 3 km in this region, the incidences clearly increased. High temperature and discomfort index, however, were not always connected with high incidences. In addition, the weather of days when high incidences were found was slightly cloudy, and in rainy or clear days such results were not at all seen.
