Subjective Symptoms of School Children Affected with Air Pollution in Osaka

Abstract

A survey was made by the Osaka Medical Association, Osaka, of symptom prevelance in all primary school children in Osaka prefecture 3 times, ie, in 1971, 1973 and 1975. The samples consisted of 609, 190-729, 048 children at 719-848 schools. The average annual levels of pollution with sulfur dioxide and nitrogen oxide were estimated for each school, to study their correlations with symptom prevalence; and the following were found:
1) The prevalence of such symptoms as eye irritation, sore throat, cough was more closely correlated with the level of nitrogen oxide from stationary sources than with that of sulfur dioxide. This fact may be considered attributable to the phenomenon that because the pollution with sulfur dioxide has decreased in recent years, the significance of sulfur dioxide as an index to the degree of air pollution has been reduced.
2) The partial correlation coefficients showed that, out of the levels of nitrogen oxide, those due to mobile source were correlated with the prevalence of such symptoms as likelihood to sneeze (p<0.001), the presence of stridor, eye irritation (p<0.01) in particular.
3) The prevalence of the above-mentioned symptoms was increased in the central part of Osaka city where there is heavy automobile traffic at each survey.
4) The regression equation of the level of nitrogen oxide as an index to pollution and symptom prevalence was estimated for 79 primary schools located in the districts where the average annual estimated level of nitrogen oxide was in the range of from 0.002-0.039 ppm. There was a correlation (p<0.05) between the level of pollution and the prevalence of such symptoms as eye irritation, sore throat, cough in the districts where the average annual estimated level of nitrogen dioxide was about 0.015 (0.013-0.017) ppm and over.