Urinary mutagenicity after controlled exposure to environmental tobacco smoke (ETS)

20 non-smokers on a defined diet low in polycyclic aromatic hydrocarbons (PAH) were exposed to environmental tobacco smoke (ETS) in an unventilated room for 8 h. The urinary mutagenicity in the 24-h urine samples as tested with the Salmonella (TA98) microsome assay did not significantly increase after exposure to either 10 ppm CO or 20-25 ppm CO. We conclude that exposure of non-smokers to ETS does not lead to an increase in their urinary mutagenicity, provided the exposure conditions are within a realistic range.