Hecht S S, Carmella S G, Murphy S E, Akerkar S, Brunnemann K D, Hoffmann D
American Health Foundation, Valhalla, NY 10595.
N Engl J Med. 1993 Nov 18;329(21):1543-6. doi: 10.1056/NEJM199311183292105.
Environmental tobacco smoke has been classified by the Environmental Protection Agency as a carcinogen causally associated with lung cancer in adults, but there have been no reports of lung carcinogens or their metabolites in the body fluids or tissues of nonsmokers exposed to environmental tobacco smoke.
Five male nonsmokers were exposed to sidestream cigarette smoke generated by machine smoking of reference cigarettes for 180 minutes on each of two days, six months apart. Sidestream smoke is the smoke that originates from the smoldering end of a cigarette between puffs. Twenty-four-hour urine samples were collected before and after exposure. The urine samples were analyzed for 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronide, which are metabolites of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a powerful lung carcinogen in rodents. NNAL is also a lung carcinogen in rodents.
The urinary excretion of the metabolites increased after exposure to sidestream smoke in all the men. The mean (+/- SD) amount of NNAL and NNAL glucuronide was significantly higher after exposure than at base line (33.9 +/- 20.0 vs. 8.4 +/- 11.2 ng per 24 hours [127 +/- 74 vs. 31 +/- 41 pmol per day], P < 0.001) and was correlated with urinary cotinine excretion (r = 0.89, P < 0.001). The nicotine concentrations in the air to which the men were exposed were comparable to those in a heavily smoke-polluted bar.
Nonsmokers exposed to sidestream cigarette smoke take up and metabolize a lung carcinogen, which provides experimental support for the proposal that environmental tobacco smoke can cause lung cancer.
美国环境保护局已将环境烟草烟雾归类为与成人肺癌有因果关系的致癌物，但尚无关于接触环境烟草烟雾的非吸烟者体液或组织中肺致癌物或其代谢物的报告。
五名男性非吸烟者在相隔六个月的两天里，每天暴露于由参比香烟机器抽吸产生的侧流香烟烟雾中180分钟。侧流烟雾是指两次抽吸之间从香烟阴燃端冒出的烟雾。在暴露前后收集24小时尿液样本。对尿液样本进行4-（甲基亚硝胺基）-1-（3-吡啶基）-1-丁醇（NNAL）及其葡糖醛酸苷的分析，它们是4-（甲基亚硝胺基）-1-（3-吡啶基）-1-丁酮（NNK）的代谢物，NNK是啮齿动物中一种强大的肺致癌物。NNAL在啮齿动物中也是一种肺致癌物。
所有男性在接触侧流烟雾后，其代谢物的尿排泄量均增加。暴露后NNAL和NNAL葡糖醛酸苷的平均（±标准差）量显著高于基线水平（分别为每24小时33.9±20.0 ng与8.4±11.2 ng [每天127±74 pmol与31±41 pmol]，P<0.001），并且与尿可替宁排泄量相关（r = 0.89，P<0.001）。这些男性所接触空气中的尼古丁浓度与重度烟雾污染酒吧中的浓度相当。
接触侧流香烟烟雾的非吸烟者会摄取并代谢一种肺致癌物，这为环境烟草烟雾可导致肺癌这一观点提供了实验依据。
