SOME POSSIBLE ULTRAVIOLET EFFECTS ON THE INCIDENCE OF SKIN CANCER AMONG JAPANESE DUE TO MODIFICATION OF THE OZONE LAYER

An epidemiological analysis was conducted in order to examine possible ultraviolet effects on the incidence of skin cancer among Japanese. Age-adjusted mortality rates (AMRs) and standardized mortality ratios (SMRs) from 1971 to 1977,ratios of cumulative mortality rates (CMRs) from 1950 to 1960 and from 1960 to 1970,and the number of patients from 1975 to 1980 were obtained for skin cancer and malignant melanoma from vital statistics of Japan. The results indicated that the AMRs of skin cancer and melanoma were much lower than those observed in other countries, and have remained almost unchanged over a long period of time. The SMRs showed a significant correlation with climatological variables; such as latitude and temperature, and socioeconomic income class. However, no significant association was found between the SMRs and the duration of sunshine available. When comparing incidences of the diseases of Japanese with those of Australian and northern Europeans, it seems evident that genetic susceptibility linked to skin colour may be a determinant factor for skin cancer