Smoke yields of tobacco-specific nitrosamines in relation to FTC tar level and cigarette manufacturer: analysis of the Massachusetts Benchmark Study.

This research assessed the relationship between the deliveries of carcinogenic tobacco-specific nitrosamines (TSNAs) and the Federal Trade Commission (FTC) "tar" ratings of US commercial cigarettes. Analysis of covariance (ANCOVA) was used to assess the explanatory power of FTC tar, the particular manufacturer, and other cigarette characteristics to predict the yields of four TSNAs (N'-nitrosonornicotine [NNN], 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone [NNK], N'-nitrosoanatabine [NAT], and N'-nitrosoanabasine [NAB]) in 26 US commercial brands tested in the 1999 Massachusetts Benchmark Study. When FTC tar alone was used to predict TSNA yield, the squared correlation coefficient (R(2)) was only 38% for NNN, 76% for NNK, 46% for NAT, and 49% for NAB. Inclusion of manufacturer-specific variables significantly (p < 0.001) increased the estimated R(2) for three of the four species of nitrosamine to: 78% for NNN, 88% for NNK, and 81% for NAT. Inclusion of other cigarette characteristics (filter type, paper permeability, tobacco weight, tip dilution) did not reduce the significance of the manufacturer-specific effects. Federal Trade Commission nicotine and carbon monoxide (CO) yields were no better at predicting TSNA levels. FTC ratings for tar, nicotine, and carbon monoxide do not tell the entire story about the comparative yields of toxic agents in marketed cigarette brands. The significant manufacturer-specific effects suggest that proprietary blending and processing of tobacco matter as well. Public, brand-by-brand disclosure of the yields of TSNA and possibly other smoke constituents appears to be warranted.