摘要:Air pollution in Tajimi city and Kasahara town, where many china factories are located, was observed by the filter paper method at 15 observation points from June, 1964 to May, 1965. In Tajimi city and in Kasahara town, 256 and 131 china factories exist, respectively, and heavy oil is used in most of these factories as fuel. From the results of this investigation, it was shown that sulfur oxide values in agricultural area were the lowest, 0.02-0.22 mg SO3/day/100 cm2 paper, and in commercial and industrial area, the values were 0.04-0.72, and 0.05-0.68 mg SO3/day/100 cm2 paper respectively. Sulfur oxide values were the lowest in September and October, but were the highest in November, December and January. Nitrogen dioxide values at these observation points were comparatively high, 0.01-0.09 mg NO2/day/100 cm2 paper, and increased in winter, too. Chloride ion values were very low, and fluorine values were relatively low.