Examination of ras (P21) proteins in plasma from workers exposed to benzene emissions from petrochemical plants and healthy controls.

Exposure of workers to benzene and polyaromatic hydrocarbons has been documented to be at relatively high levels in the production of benzene and in the coking process at a petrochemical plant in the oil shale area in Estonia. Altogether 97 plasma samples from workers and 40 from unexposed matched referents from two samplings in different seasons were analyzed for the presence of ras (P21) proteins; of the workers 50 were exposed to benzene in the benzene production plant and 47 to polyaromatic hydrocarbons and benzene in a cokery. Proteins were separated by gel electrophoresis, transferred to a nitrocellulose membrane by Western blotting and detected by chemiluminescence, using a monoclonal antibody as the primary antibody. There were no statistically significant differences between the exposed and the referent groups. The results are thus in keeping with the lack of exposure related cytogenetic effects for this same workforce.