Aromatic DNA adducts in white blood cells of foundry workers

Blood samples were obtained from volunteers working in a Finnish iron foundry who were occupationally exposed to polycyclic aromatic hydrocarbons (PAH) and from control subjects not known to be occupationally exposed to this class of chemical carcinogens. Foundry workers were classified as belonging to high, medium or low exposure groups according to their exposure to airborne benzo[a]pyrene: high, greater than 0.2: medium, 0.05-0.2: low, less than 0.05 micrograms benzo[a]pyrene/m3 air). Aromatic adducts were found to be present in white blood cell DNA from most of the exposed workers using the enzyme-linked immunosorbent assay (ELISA) to detect aromatic DNA adducts and the 32P-postlabelling technique. There was a dose-response relationship between the estimated exposure and adduct levels by both methods, and a reasonable correlation between the results of the immunoassay and postlabelling carried out in two laboratories. The levels of adducts found in the samples from the high and medium exposure groups by ELISA ranged up to five adducts in 10(7) nucleotides: the aromatic adducts detected by the postlabeling assay were at a level of two adducts/10(8) nucleotides in the high and medium exposure categories. No effect due to age, sex or the smoking habits of the subjects was observed. The results indicate that DNA extracted from white blood cells of highly exposed workers is more likely to contain aromatic DNA adducts than that from workers without occupational exposure to PAH, but large interindividual variations were evident. This study suggests that the antibody and 32P-postlabelling assays may be useful in monitoring human exposure to known and previously unidentified environmental genotoxic agents.