The daily number of new patients with acute respiratory and digestive diseases was investigated from July 11 to September 10, 1975 using policyholders of the National Health Insurance living in the northern part of Amagasaki, Hyogo Prefecture and in Nagaokakyo, Oyamazaki, Kyoto Prefecture. Because the number of new patients on Monday was very large, and that on Saturday and on Sunday was very small, only data for Tuesday, Wednesday, Thursday and Friday were used in this study.
Daily maximum. and minimum temperatures, daily mean relative humidity, daily mean wind velocity, daily maximum oxidant and SO2 concentrations were the variables chosen to represent meteorological conditions and air pollution. The correlation between daily incidence of acute respiratory and digestive diseases and these meteorological conditions and air pollution was evaluated by the method of lagged cross-correlation.
1) The daily number of new patients with acute respiratory disease was positively correlated with the daily maximum temperature before 5 to 7 days. The daily number of new patients with acute digestive disease was positively correlated with the daily minimum temperature on the same day and before 1 to 3 days. These phenomena were similar in both districts.
2) In Amagasaki, the daily number of new patients. with acute respiratory disease was positively correlated with the daily maximum SO2 concentration before 4 to 10 days. However, no positive correlation was observed in Nagaokakyo, Oyamazaki where the SO2 concentration was much lower.
