Atmospheric Temperature and Death

Abstract

The statistical study was performed on the correlation between atmospheric temperature and seasonal rise and fall of daily death cases based on the death certificates in Tokyo during 1952. Cases in Izu Islands and those of acute infectious diseases were excluded. The results obtained were as follows : 1.A trend was observed that in the summer season when the temperature was high, the death frequency was generally low, but on the days of extremely high temperature the death cases increased. In the winter season when the temperature was low, the death frequency was generally high, but on the days with rather higher minimum and mean temperature the death cases decreased. On the days with higher death frequency the minimum temperature was low. In spring and autumn these trends are similar to that in winter. 2.There could be observed no particular trends of increase or decrease of the death cases on the days of typical pressure pattern of summer or winter season. 3.In summer, marked increase in death cases was seen on the days with remarkable fluctuation of diurnal temperature.A similar trend was observed also in winter, although it was not statistically significant. 4.In summer the death frequency was low on the days when the maximum temperature was remarkably lower than the preceeding day. In autumn, winter and spring there were no significant correlation. 5.In summer, the fluctuation of humidity was slight and the significant correlation between humidity and the death frequency could not be comfirmed. In winter, however, the fluctuation of humidity was remarkable and the death frequency showed a tendency to drop on the days of rather higher humidity. 6. On the days with high discomfort index, i.e. D.I.>80, the death frequency was generally high. The high discomfort index was principally due to high temperature. Accordingly the influence of D.I. on the death frequency depends for the most part upon the factor of temperature and very little upon that of humidity.