A COMPARISON OF THE MUTAGENICITY OF MAINSTREAM CIGARETTE-SMOKE CONDENSATES FROM A REPRESENTATIVE SAMPLE OF THE US CIGARETTE MARKET WITH A KENTUCKY REFERENCE CIGARETTE (K1R4F)

The Salmonella mutagenicity assay has been used to investigate the mut agenicity of cigarette smoke and cigarette smoke condensate. The Kentu cky reference (K1R4F) cigarette is designed to be representative of fu ll-flavor, low-tar cigarettes sold in the U.S. and to serve as a refer ence standard for comparative studies on the chemistry and biological activities of cigarette smoke and condensate. The objective of this st udy was to determine if the mutagenicity of mainstream smoke condensat e from the K1R4F, as measured by the Salmonella mutagenicity assay, is representative pf the mutagenic activity of U.S. cigarettes, Mainstre am smoke condensates prepared in dimethyl sulfoxide from the KIR4F and 73 brand styles (representing greater than 70% of the total U.S. ciga rette market) were assayed using Salmonella typhimurium TA98 and TA100 (+S9) at concentrations of 0, 25, 50, 75, 100, 125 and 250 mu g/plate . Revertants/mg condensate were determined by calculating the slopes o f the dose-response curves using linear and nonlinear regression model s. Revertants/cigarette were determined by multiplying the revertants/ mg condensate by the mg condensate/cigarette. No significant differenc es (p > 0.05) were observed between the mean mutagenicity of U.S, mark et and K1R4F mainstream smoke condensates in terms of revertants/mg co ndensate or revertants/cigarette. Increased variability in mutagenicit y was observed among the U.S. brands versus that of the K1R4F. This is not surprising since variability among the U.S. brands would be expec ted to have both measurement error and brand style variability while t he K1R4F variability contains only the measurement error portion. Thes e results demonstrate that the K1R4F is a representative model for the U.S. cigarette market in comparative Salmonella mutagenicity studies using mainstream smoke condensates.