Abstract
Yokkaichi city was divided into 1011 districts on the basis of SO2 concentration in the air, measured over a 12-month period. The relationship between the SO2 concentration and the incidence of respiratory disease was determined by the use of questionnaires and National Health Insurance Bills.
The diseases which showed a high correlation with SO2 concentration were bronchial asthma in school children and chronic bronchitis in those over 40 years of age.
We found that the incidence of respiratory diseases was increased in the areas where the SO2 concentration averaged more than 0.550.65mg/day (0.02ppm).
