Environmental factors affecting the life span of men and women

For several years, the average life span of men and women in Japan has been the longest in the world. Improvements in food supply, clothing, living conditions, labor, etc. in parallel with economic development after World War II have certainly been important in this prolongation of the life span. We examined whether certain environmental factors also influence the life span of residents in various cities of Japan. Seventy-seven cities in Japan were selected for the analysis of the life span. Four environmental factors; atmospheric pressure, temperature, duration time of sunshine and relative moisture, were tested. Long life span in men was found to be correlated with low atmospheric pressure but not with the others, while long life span in women was correlated with high temperature but not with the others. In other words, low atmospheric pressure in uplands and warm weather in southern areas are important for the prolongation of life span. There was a tendency for men living under low atmoshperic pressure and women living in warm areas to have a low level of granulocytes and a high level of lymphocytes in the blood. These results suggest that specific environmental factors affect the physical condition and immunologic state of humans and thus have an influence on their life span, if they are free from economical restraints.