A study of Ohio residents by place of birth identified an increased cancer risk (100% excess) among black migrants born in the South compared with blacks born in Ohio. The migration of blacks from South to North for the purpose of industrial employment was extensive between the years 1940-1970. The hypothesis is that biological and social imprints (poverty, malnutrition, genetics), endemic of the early years of life, provide a physiological imbalance which provides the basis for increased susceptibility to adverse environmental stresses subsequent to migration. Findings consistent with this hypothesis were obtained in a prospective study of steel workers in which 2,543 men in coke plant operations were included, in which a prior high rate for lung cancer had already been established. A strong association was found between place of birth and place of death from lung cancer in the nonwhite coke plant workers. Examination of these death certiricates revealed that 33 of 35 deaths of lung cancer occurred among men born in the South.