Research Centre of the CHUM, Montreal, Québec, Canada.
Occup Environ Med. 2013 Mar;70(3):164-70. doi: 10.1136/oemed-2012-100931. Epub 2013 Jan 15.
We investigated the association between workplace lead exposure and lung cancer risk, separately for organic lead and for inorganic lead, from either engine emissions or from other sources.
Two population-based case-control studies were carried out in Montreal (1979-1986 and 1996-2002) to investigate occupational factors in relation to lung cancer among 1593 men with histologically confirmed incident lung cancer, and 1426 controls from the general population. Interviews elicited information on sociodemographic characteristics, lifetime smoking and occupational history. Chemists translated each job into potential chemical exposures. Cumulative indices of exposure were derived and classified into non-substantial and substantial exposure. ORs adjusted for several potential confounders including smoking, and 95% CIs were estimated by logistic regression.
Lifetime prevalences of exposure in Study I were 3% for organic lead, 40% for inorganic lead from engine emissions and 17% for inorganic lead from other sources; corresponding prevalences in Study II were 4%, 19% and 16%, respectively. No associations were observed when comparing ever to never exposed subjects in pooled analyses (organic lead, OR=1.39, 95% CI 0.77 to 2.52; inorganic lead from engine emissions: OR=0.89, 95% CI 0.72 to 1.09; inorganic lead from other sources: OR=0.99, 95% CI 0.76 to 1.29). Nor were these exposures associated with lung cancer in subjects with substantial cumulative exposure.
In this large study, using a blinded expert-based assessment of lifetime occupational exposure and adjustment for several potential confounders, we observed no increased risk of lung cancer with exposure to lead compounds.
我们分别研究了职业环境中有机铅和无机铅（来自发动机排放或其他来源）暴露与肺癌风险之间的关系。
在蒙特利尔进行了两项基于人群的病例对照研究（1979-1986 年和 1996-2002 年），以调查 1593 名经组织学证实的肺癌男性患者和来自普通人群的 1426 名对照者的职业因素与肺癌的关系。访谈中收集了社会人口统计学特征、终生吸烟史和职业史的信息。化学家将每个工作转换为潜在的化学暴露。累积暴露指数，并分为非实质性暴露和实质性暴露。采用逻辑回归估计调整了几个潜在混杂因素（包括吸烟）后的 OR 值和 95%CI。
在研究 I 中，有机铅的终生暴露率为 3%，来自发动机排放的无机铅为 40%，来自其他来源的无机铅为 17%；在研究 II 中，相应的暴露率分别为 4%、19%和 16%。在汇总分析中，比较暴露组和未暴露组时，未观察到关联（有机铅：OR=1.39，95%CI 0.77-2.52；来自发动机排放的无机铅：OR=0.89，95%CI 0.72-1.09；来自其他来源的无机铅：OR=0.99，95%CI 0.76-1.29）。在累积暴露量较大的人群中，这些暴露也与肺癌无关。
在这项大型研究中，我们使用基于专家的盲法评估终生职业暴露，并调整了几个潜在混杂因素，未观察到铅化合物暴露与肺癌风险增加相关。
