Diesel motor exhaust and lung cancer mortality: reanalysis of a cohort study in potash miners
Diesel motor exhaust and lung cancer mortality: reanalysis of a cohort study in potash miners
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DOI：
10.1007/s10654-013-9784-0
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发表时间：
2013-02-01
影响因子：
13.6
通讯作者：
Gellissen, Johannes
中科院分区：
文献类型：
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作者：
Moehner, Matthias;Kersten, Norbert;Gellissen, Johannes
重新分析的目的是重新评估与钾肥矿工职业暴露于柴油汽车尾气相关的肺癌风险，同时控制吸烟和既往职业史等潜在混杂因素。我们的调查是基于对近6000名德国钾肥矿工的队列研究，这些矿工从1970年到2001年接受了跟踪调查。重新分析还考虑了钾肥开采，特别是铀矿开采之前的就业时期。采用不同的方法(嵌套病例对照研究和COX模型)调整混杂因素。风险暴露的估计值被重新计算，落后于风险暴露5年。暴露组由可吸入元素碳(REC)累积暴露量估计值和职业类别来定义，其中暴露量最初是通过对不同职业的总碳的代表性测量来估计的。生产工人的REC浓度最高，大约是其他职业的两倍。重新分析显示，虽然所有研究对象中约4%的人以前曾在铀矿工作过，但10.3%的晚期肺癌病例是这样做的。尽管它们的绝对数量很少，但相应的相对风险估计值却显著升高。我们的分析没有显示出累积的REC暴露与肺癌风险之间有任何显著的关联。将累积REC暴露作为连续变量引入条件Logistic回归模型，调整了吸烟和以前的工作，优势比OR=1.04[0.70-1.53](95%)。研究结果没有证据表明REC暴露与肺癌风险之间存在关联。只有非常高的累积剂量，对应于生产地区至少20年的暴露，才能检测到一些可能风险增加的微弱迹象。这项研究强调了在职业研究中评估整个职业史的重要性，特别是如果假设的剂量-反应-关系很弱的话。
The aim of the reanalysis is to reassess lung cancer risk associated with occupational exposure to diesel motor exhaust in potash miners, while controlling for potential confounders such as smoking and previous occupational history. Our investigation is based on a cohort study of nearly 6,000 German potash miners, who were followed up from 1970 to 2001. The reanalysis also takes into account the employment periods before potash mining, in particular uranium mining. Different approaches (nested case-control study and Cox model) were used to adjust for confounding. The exposure estimates were recalculated, lagging the exposure by 5 years. Exposure groups were defined by tertiles of cumulative respirable elemental carbon (REC) exposure estimates and occupational categories, where exposure was estimated originally by representative measurements of total carbon for different occupations. The highest REC concentration was measured for production workers, about twice as much as for other occupations. The reanalysis revealed that while about 4 % of all study subjects had worked earlier in uranium mines, 10.3 % of later lung cancer cases did so. Although their absolute number was small, the corresponding relative risk estimator was significantly elevated. Our analysis did not show any notable association between cumulative REC exposure and lung cancer risk. Introducing cumulative REC exposure as a continuous variable into the conditional logistic regression model yielded an odds ratio of OR = 1.04 [0.70-1.53](95 %) adjusted for smoking and previous employment. The study results give no evidence for an association between REC exposure and lung cancer risk. Only for very high cumulative dose, corresponding to at least 20 years of exposure in the production area, some weak hints for a possible risk increase could be detected. The study underlines the importance of assessing the entire occupational history in occupational studies, especially if the supposed dose-response-relationship is weak.