CHILDHOOD LEUKEMIA AND RURAL-POPULATION MOVEMENTS - GREECE, ITALY, AND OTHER COUNTRIES

Mortality from childhood leukemia was examined particularly in rural c ountries in relation to any major rural-urban migration. Significant i ncreases have been found in other situations of rural population mixin g as predicted by the infection hypothesis. The 1950s and 1960s were o f most interest since it preceded the decline in mortality brought abo ut by effective chemotherapy in many countries. The 33 countries cover ed were all those in the World Health Organization's mortality databas e. No sensitive measure of rural-urban migration is available for inte rnational comparisons. However, it seems noteworthy that Greece and It aly, the two countries with the most striking levels of rural migratio n in the 1950s and 1960s, also had unusually high mortality rates from childhood leukemia. Greece was most affected proportionally by these population movements and from 1958 to 1972 had the highest recorded mo rtality from this cause in the world The problems of international com parisons of mortality data dictate caution in drawing conclusions. How ever, against a background of other work on population mixing, and in the light of certain considerations, we suggest that the marked rural population mixing in Greece and Italy may have contributed to their hi gh mortality rates from childhood leukemia in the 1950s and 1960s.