Cytogenetic investigations of human subjects occupationally exposed to chemicals from the petroleum-processing industry.

A cytogenetic investigation was carried out of 55 workers from the petroleum-processing industry and of 30 control subjects. The frequencies of both structural and numerical chromosome aberrations and of sister chromatid exchanges were determined simultaneously and the relationship among these cytogenic indices were analyzed. The incidence of chromosome aberrations and sister chromatid exchanges among the petroleum workers was higher than that among the controls. The cytogenic indices demonstrated a clear dependence on the working environment of the subjects and a correlation with the existence of some reproductive failures in the families of the exposed workers. Our results indicate the presence of some mutagenic risk in the working environment of some of the divisions in the petroleum-processing industry due to the genotoxic influence on the somatic cells of the exposed workers at a cytogenetic level. This potential risk is mainly associated with the presence of some heavy oil-fractions and polycyclic aromatic hydrocarbons in the working environment.