摘要：To examine the aggregation of leukemia in one area, leukemia mortality in Hyogo prefecture during 1979-1988 was analyzed. Serum vitamin A (V-A) levels of 40 males aged 30-40 years old were examined in 4 areas of Hyogo prefecture and the relationship between the incidence of leukemia and V-A level was discussed. In the Toyooka area, the areal distribution of leukemia mortality was also analyzed. The results are follows as: 1) Higher leukemia mortality rate per year was found in the north part and the heavy industrial areas of the south part of Hyogo prefecture. Mortality rate of leukemia showed a positive correlation to the rate of attendance at fermentation among the inhabitants of these areas. 2) In the Toyooka area, time-distance aggregation of leukemia among subjects aged over 16 years old was not detected during 1985-1988. But there was a positive correlation between the time and distance intervals. The distribution of leukemia patients showed a Polya-Eggenberger distribution. This means a tendency to time aggregation of leukemia incidence. Thus, it is important to investigate nutrition intake and occupational exposure in relation to leukemia incidence. There was a 6 year-cycle of leukemia incidence. This cycle may relate to the natural radiation exposure. 3) In Toyooka, where the leukemia incidence was higher, the serum V-A level was lower than the other areas. There was a negative correlation between the V-A level and leukemia incidence. However, serum carotene level did not relate to leukemia mortality. These results suggest that V-A intake may have a beneficial effect in the prevention of leukemia.
