INDUCTION OF DNA-ADDUCTS IN-VIVO IN RAT LUNG-CELLS BY FUME CONDENSATES OF ROOFING ASPHALT

Many workers in the highway construction and roofing industries are po tentially exposed to asphalt fumes. However, Little is known regarding the carcinogenic hazards of these fumes to the exposed workers. Previ ous studies have shown that condensates of asphalt fumes are weakly mu tagenic to bacteria and are capable of inducing micronucleus formation in cultured mammalian cells. In this study, the induction of DNA addu cts in vivo in lung and white blood cells (WBCs) of rats by fume conde nsates of type I and type III roofing asphalts was investigated using P-32-postlabeling analysis. Male CD rats (3/group) received 3 intratra cheal instillations of fume condensates in a 24-h period. DNA from bot h lung cells and WBCs were isolated and used to detect DNA adducts. Co ndensates of both roofing asphalt fumes caused DNA adduct formation in rat lung cells in a similar dose-related manner. Under the conditions studied, however, neither type I nor type III fume condensate induced DNA adducts in WBCs. These results indicate that 1) condensates of fu mes from both type I and type III have similar genotoxic activity, 2) chemicals in the condensates of roofing asphalt fumes can covalently b ind to the DNA of rat lung cells, and 3) WBCs may not be a suitable su rrogate for lung cells in DNA adduct studies of workers exposed to roo fing asphalt fumes. (C) 1998 Wiley-Liss, Inc.