Rousseau M-C, Parent M-E, Nadon L, Latreille B, Siemiatycki J
INRS--Institut Armand-Frappier, University of Quebec, Laval, Quebec, Canada.
Am J Epidemiol. 2007 Nov 1;166(9):1005-14. doi: 10.1093/aje/kwm183. Epub 2007 Aug 9.
The International Agency for Research on Cancer recently classified inorganic lead as a probable carcinogen, while organic lead remained unclassifiable. Uncertainty persists because of limited epidemiologic evidence. The authors addressed the relation between occupational exposure to lead and the risk of 11 types of cancer among men in a case-control study conducted in Montreal, Quebec, Canada, in the 1980s. Incident cases (n = 3,730) and general population controls (n = 533) were interviewed to elicit information on job history and potential confounders. Expert chemists translated each job into a list of substances to which the subject had potentially been exposed. Exposure to lead was classified into three categories: organic lead (3% of subjects ever exposed), inorganic lead (17%), and lead in gasoline emissions (39%). Odds ratios and 95% confidence intervals were estimated by logistic regression using two control groups: general population controls and cancer controls. Stomach cancer was associated with organic lead when the authors used population controls (odds ratio (OR) = 3.0, 95% confidence interval (CI): 1.2, 7.3) and cancer controls (OR = 2.0, 95% CI: 1.1, 3.8) and with substantial exposure to lead in gasoline emissions when they used cancer controls (OR = 2.9, 95% CI: 1.4, 5.9). There was no association with inorganic lead and little evidence for associations with other cancer types.
国际癌症研究机构最近将无机铅列为可能的致癌物，而有机铅仍无法分类。由于流行病学证据有限，不确定性依然存在。作者在20世纪80年代于加拿大魁北克省蒙特利尔市开展的一项病例对照研究中，探讨了职业性铅暴露与男性11种癌症风险之间的关系。对发病病例（n = 3730）和一般人群对照（n = 533）进行访谈，以获取工作经历和潜在混杂因素的信息。专业化学家将每份工作转化为受试者可能接触过的物质清单。铅暴露分为三类：有机铅（曾接触过的受试者中有3%）、无机铅（17%）和汽油排放中的铅（39%）。使用两个对照组（一般人群对照和癌症对照）通过逻辑回归估计比值比和95%置信区间。当作者使用人群对照时，胃癌与有机铅有关（比值比（OR）= 3.0，95%置信区间（CI）：1.2，7.3），使用癌症对照时也有关（OR = 2.0，95% CI：1.1，3.8）；当使用癌症对照时，胃癌与大量接触汽油排放中的铅有关（OR = 2.9，95% CI：1.4，5.9）。无机铅与之无关，与其他癌症类型相关的证据也很少。
