Investigation of the mutagenic activity of tobacco smoke

The genotoxic effect of whole tobacco smoke was studied employing the Salmonella/microsome mutagenicity assay, the micronucleus test in mouse bone marrow and UDS in peripheral human lymphocytes. It was established that tobacco smoke (120-480 cm3 in a 16-1 glass chamber, at 1-10 min exposure time) induced a 3-9-fold increase of spontaneous his+ reversion mutation rate in S. typhimurium TA98, but not in strains TA97a, TA100 and TA102. Addition of S9 mix obtained from the liver of Aroclor 1254-treated rats was necessary to reveal the mutagenic activity of tobacco smoke. Treatment of BDF1 mice placed in a 14-1 glass chamber with tobacco smoke (600 cm3 smoke, 2 exposures of 30 min each, with a 1-min interval between them) caused a 2-fold dose-dependent elevation of the number of micronucleated PCE in bone marrow. No cumulative effect was detected when mice were treated with tobacco smoke during 2-28 consecutive days. The effect observed 24 h after tobacco-smoke exposure was abolished 48 h later. Tobacco smoke (180 or 360 cm3) passed through the culture medium (with or without S9 mix) of human peripheral lymphocytes (the cells were then incubated for 60 min at 37 degrees C) did not increase the spontaneous rate of UDS. Both the Salmonella/microsome mutagenicity assay employing S. typhimurium TA98 strain and the micronucleus test in mouse bone marrow might be useful in studying tobacco smoke-induced mutagenesis.