Chromosome aberrations in blood lymphocytes from petroleum refinery workers.

To evaluate the possible cytogenetic consequences of exposure of human populations to petrochemicals, the frequency of chromosomal aberrations was studied in blood lymphocytes obtained from 233 persons working at different locations in a large oil refinery (184 exposed and 49 worksite controls) and from 47 individuals who served as community controls. Chromosomal aberrations occurred with frequencies (mean +/- SEM) between 0.023 +/- 0.013 and 0.037 +/- 0.011 breaks per cell (1.56 +/- 0.87% to 2.66 +/- 0.54% aberrant cells) in the exposed groups. These values, with the exception of those observed in two workshops (crude oil unloading as well as petroleum tanker washing and lubrication), were significant compared to the presumably spontaneous (control) levels (0.015 +/- 0.004 to 0.021 +/- 0.007 breaks per cell and 1.17 +/- 0.29% to 1.46 +/- 0.40% aberrant cells). Cigarette-smoking was not associated with increased chromosomal aberrations in the exposed and in the control groups.