Bull. Spec. CORESTA Congress, Lisbon, 2000, p. 168, ST23

Biological studies on smoke condensates from cigarettes made with low nitrosamine flue-cured tobacco

DOOLITTLE D.J.; AVALOS J.T.; BOMBICK B.R.; PUTNAM K.P.; BOMBICK D.W.; NESTOR T.B.; GENTRY J.S.
R.J. Reynolds Tobacco Company, Winston-Salem, NC, USA
R. J. Reynolds Tobacco Company recently developed a process for flue-curing tobacco that results in substantially lower concentrations of tobacco-specific nitrosamines. The technology is based on the use of heat exchangers instead of direct-fired burners for heating the air in tobacco barns during the curing process. We conducted studies to evaluate and compare the genotoxic and cytotoxic potential of smoke condensates prepared from cigarettes made exclusively with tobacco cured using either direct-fired curing or heat exchange curing. The Ames test was used to evaluate genotoxicity, and the Neutral Red assay was used to evaluate cytotoxicity. All smoke condensates were mutagenic in Salmonella strains TA98, TA1538 and YG1024 and all were cytotoxic in the mammalian CHO cell line. There were no statistically significant (p<0.05) differences in the mutagenicity or cytotoxicity of smoke condensates from cigarettes made from either direct-fired or heat exchanged flue-cured tobacco. These results indicate that, although heat exchange curing reduces the concentration of tobacco-specific nitrosamines in flue-cured tobacco by 90% compared to direct-fired curing, there was no change in the biological activity of the tobacco as measured in the tests used.