Benzo[a]pyrene in the Mainstream Smoke of Little Cigars

Little cigars are similar to cigarettes, with respect to dimensions, filters, and overall appearance. Some smokers also use little cigars as substitutes for cigarettes. Comparison of little cigars with cigarettes is relevant to understanding their respective public health impact. To understand their relative toxicities, mainstream smoke yields of benzo[a]pyrene (B[a]P), a human carcinogen, were measured for 60 commercial little cigars. The little cigars were smoked on a linear smoking machine using the International Organization of Standardization (ISO) nonintense and Canadian Intense (CI) smoking regimens followed by analysis with a validated gas chromatography/mass spectrometry (GC/MS) method. The average analytical quantitative variability of the measured little cigar constituents was lower compared to previously tested commercial cigarettes (%RSD 9.6 vs 14.5, respectively). B[a]P yields ranged from 14.5-44.0 ng/cigar (ISO) and 24.0-65.7 ng/cigar (CI). The mean ISO yield is 25.5 ng/cigar versus the CI yield of 42.2 ng/cigar, which are 2.5- and 2-fold greater, respectively, than the corresponding mean cigarette yields. When normalized to tobacco weight, B[a]P yields of the little cigars are 1.5- (ISO) and 1.3- (CI) fold greater than cigarette yields. B[a]P smoke yields are known to correlate with tobacco weight. The little cigar B[a]P yield correlations to tobacco weight (CI R² = 0.35; ISO R² = 0.24) are similar to cigarette yield correlations (CI R² = 0.31; ISO R² = 0.21). Other physical properties (i.e., filter length, filter ventilation, and packing density) that may impact B[a]P smoke yields for the little cigars had very weak correlations. Except for cigarette packing density, cigars and cigarettes have similar correlations between B[a]P yields and physical design parameters. In summary, the little cigars, although physically similar to cigarettes, differ in smoke chemistry by generating higher B[a]P yields, even when normalized to tobacco weight.