Differences in lung cancer rates have been observed in different ethnic groups which may be due, in part, to differences in carcinogen exposure. To examine this, exposure to cigarette smoke constituents was compared between 97 adult Caucasian smokers in the United Kingdom and 43 adult Japanese smokers in Japan. All smokers smoked the same brand of cigarettes (6 mg ISO ‘tar’, 0.5 mg nicotine, 8.0 mg CO); although cigarettes in the United Kingdom were fitted with a plain cellulose acetate filter (UKPF) while in Japan the cigarettes had a cellulose acetate filter containing charcoal (JCF). Mainstream smoke chemistry of UKPF and JCF cigarettes was determined according to ISO smoking conditions: 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone [NNK] (43.0±3.8 vs. 61.9±4.3 ng/cig.), pyrene (28.4±1.0 vs. 28.5±0.4 ng/cig.), acrolein (50.0±3.1 vs. 28.0±1.4 μg/cig.), benzene (30.5±0.4 vs. 16.9±0.9 μg/cig.), and 1,3-butadiene (28.1±0.9 vs. 19.1±0.7 μg/cig.). Blood samples were analyzed for COHb and plasma cotinine. Urine samples (24 h) were analyzed for metabolites of nicotine (NEQ; nicotine + 5 metabolites), NNK (total NNAL; 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol [NNAL] and glucuronides), pyrene (1-HOP; 1-hydroxypyrene), acrolein (3-HPMA; 3-hydroxypropylmercapturic acid), benzene (S-PMA; S-phenylmercapturic acid), and 1,3-butadiene (MHBMA; monohydroxybutenylmercapturic acid). Caucasians and Japanese smokers rated similarly on the Fagerström test for nicotine dependence (FTND sum score: 4.64±1.97 vs. 4.47±1.93; p=0.632) and smoked a similar number of cigarettes per day (19.2± 4.9 vs. 17.9±3.6; p=0.070). Caucasian smokers had a slight but significant increase in COHb compared to Japanese smokers (5.73±1.83 vs. 5.05±1.82 % saturation; p=0.045), and a significant increase in plasma cotinine (252.3±91.3 vs. 191.1±91.6 ng/mL; p=0.0004) and total nicotine excretion (16.02±6.93 vs. 8.24±3.78 mg NEQ/24 h: p<0.0001). Excretion of other particulate phase smoke constituents was not significantly different in Caucasian and Japanese smokers (total NNAL: 306.3±157.2 vs. 276.0±181.3 ng/24 h; 1-HOP: 182.1±81.8 vs. 171.1±73.8 ng/24 h). Excretion of gas phase cigarette smoke constituents was significantly higher in Caucasian compared to Japanese smokers: 3-HPMA (2.15±1.10 vs. 1.47±0.57 mg/24 h; p<0.0001), S-PMA (5.17±3.05 vs. 2.22±1.47 μg/24 h; p<0.0001), and MHBMA (6.20±7.14 vs. 1.75±1.35 μg/24 h; p<0.0001). The results of this study provide additional support for the observation that charcoal filters may result in reductions in volatile gas phase smoke constituents.
[Proc Amer Assoc Cancer Res, Volume 46, 2005]