A study of refinery workers has found exposure to crude oil may lead to a marked increase in kidney cancer risk. Researchers, whose findings were published in the Journal of Occupational and Environmental Medicine, looked at cancer patterns in 9,454 workers employed in the oil refinery industry in Finland in the period 1967 to 1982 and found there was a threefold increase in the kidney cancer risk for exposure to hydrocarbons in crude oil.

Ahti Anttila and others. Kidney cancer risk in oil refining in Finland: a nested case-referent study, Journal of Occupational and Environmental Medicine, volume 57, issue 1, pages 68–72, January 2015. Risks 686.