[The cytogenetic effects (the frequency of micronuclei) in lymphocyte cultures from the peripheral blood of workers in automobile tire manufacture].

At the Preparatory Workshop of the Plant for Automobile Tires (PAT), Sofia, complex investigations were undertaken to reveal possible genotoxic exposure. The studies included chemical analyses for levels of identifiable human carcinogens in the occupational ambient air (benz(a)pyrene, mineral oils, 2-naphthylamine); special techniques--questionnaire investigations and cytogenetic analysis by cytokinesis-block micronucleus method in peripheral lymphocyte cultures from 23 workers in occupational groups at risk; and urinalysis for contents of mercapturic acids. An out-of-house control group of 13 nonexposed subjects was concurrently investigated. For contents of benz(a)pyrene and mineral oils exceeding 2.5 to 3.5 times the respective occupational environment MACs, evidence from cytogenetic analysis showed substantial, 4-fold, increase in indexes of genotoxic impairment (frequency of micronucleated-binucleated lymphocytes, number of micronuclei per 1000 binucleated lymphocytes) in the workers investigated. These results are an indicator of genotoxic exposure and point to an increased potential risk of cancer development in the group of workers studied.