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 spectr
um of ERP-ETS was determined by colony probe hybridization and polymerase c
hain reaction/DNA sequence analysis in approximately 2,370 His(+) revertant
s. 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 contro
l room induced approximately 94.3% such deletions, while the ERP-ETS collec
ted From the passenger cars induced approximately 89.6% such deletions. The
ERP-ETS either from the control room or from the passenger cars induced ap
proximately 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 T
A100. (C) 1999 Wiley-Liss, Inc.