Mutation spectrum in Salmonella induced by environmental tobacco smoke

Environmental tobacco smoke (ETS) is a major source of indoor air pollution. Extractable-respirable particulate (ERP) from the ETS-contaminated indoor air (ERP-ETS) was collected from six passenger train cars and one control room. The mutagenicity of ERP-ETS was tested in the Ames/Salmonella test in the presence of male rat liver microsomal fraction S9. The mutation spectrum of ERP-ETS was determined by colony probe hybridization and polymerase chain reaction/DNA sequence analysis in approximately 2,370 His+ revertants. The results indicate that the majority of ERP-ETS-induced mutations were a two-base deletion of GC or CG within the hotspot sequence of CGCGCGCG at the frameshift hisD3052 allele in strain TA98. The ERP-ETS from the control room induced approximately 94.3% such deletions, while the ERP-ETS collected from the passenger cars induced approximately 89.6% such deletions. The ERP-ETS either from the control room or from the passenger cars induced approximately 74% C/G --> A/T transversions, and approximately 23% C/G --> T/A transitions within the primary target CCC at the hisG46 allele in strain TA100.