ERS Inc, Morgantown, WV, USA.
J Natl Cancer Inst. 2012 Jun 6;104(11):869-83. doi: 10.1093/jnci/djs035. Epub 2012 Mar 5.
Current information points to an association between diesel exhaust exposure and lung cancer and other mortality outcomes, but uncertainties remain.
We undertook a cohort mortality study of 12 315 workers exposed to diesel exhaust at eight US non-metal mining facilities. Historical measurements and surrogate exposure data, along with study industrial hygiene measurements, were used to derive retrospective quantitative estimates of respirable elemental carbon (REC) exposure for each worker. Standardized mortality ratios and internally adjusted Cox proportional hazard models were used to evaluate REC exposure-associated risk. Analyses were both unlagged and lagged to exclude recent exposure such as that occurring in the 15 years directly before the date of death.
Standardized mortality ratios for lung cancer (1.26, 95% confidence interval [CI] = 1.09 to 1.44), esophageal cancer (1.83, 95% CI = 1.16 to 2.75), and pneumoconiosis (12.20, 95% CI = 6.82 to 20.12) were elevated in the complete cohort compared with state-based mortality rates, but all-cause, bladder cancer, heart disease, and chronic obstructive pulmonary disease mortality were not. Differences in risk by worker location (ever-underground vs surface only) initially obscured a positive diesel exhaust exposure-response relationship with lung cancer in the complete cohort, although it became apparent after adjustment for worker location. The hazard ratios (HRs) for lung cancer mortality increased with increasing 15-year lagged cumulative REC exposure for ever-underground workers with 5 or more years of tenure to a maximum in the 640 to less than 1280 μg/m(3)-y category compared with the reference category (0 to <20 μg/m(3)-y; 30 deaths compared with eight deaths of the total of 93; HR = 5.01, 95% CI = 1.97 to 12.76) but declined at higher exposures. Average REC intensity hazard ratios rose to a plateau around 32 μg/m(3). Elevated hazard ratios and evidence of exposure-response were also seen for surface workers. The association between diesel exhaust exposure and lung cancer risk remained after inclusion of other work-related potentially confounding exposures in the models and were robust to alternative approaches to exposure derivation.
The study findings provide further evidence that exposure to diesel exhaust increases risk of mortality from lung cancer and have important public health implications.
目前的信息表明，柴油废气暴露与肺癌和其他死亡率结果之间存在关联，但仍存在不确定性。
我们对 8 家美国非金属矿场的 12315 名接触过柴油废气的工人进行了队列死亡率研究。历史测量值和替代暴露数据以及研究工业卫生测量值用于为每位工人得出可吸入元素碳（REC）暴露的回溯定量估计。标准化死亡率比和内部调整的 Cox 比例风险模型用于评估 REC 暴露相关风险。分析既未滞后也未滞后，以排除最近的暴露，例如在死亡日期前 15 年内发生的暴露。
与州死亡率相比，完整队列的肺癌（1.26，95%置信区间[CI] = 1.09 至 1.44）、食管癌（1.83，95%CI = 1.16 至 2.75）和尘肺病（12.20，95%CI = 6.82 至 20.12）的标准化死亡率较高，但全因、膀胱癌、心脏病和慢性阻塞性肺疾病死亡率没有升高。在完整队列中，工人位置（曾在地下工作与仅在地表工作）的差异最初掩盖了与肺癌的阳性柴油废气暴露反应关系，但在调整工人位置后变得明显。对于曾在地下工作且工作年限超过 5 年的工人，随着 15 年滞后的累积 REC 暴露量的增加，肺癌死亡率的危险比（HR）增加到最高在 640 至小于 1280μg/m(3)-y 类别与参考类别（0 至 <20μg/m(3)-y；30 例死亡与 93 例总死亡中的 8 例死亡；HR=5.01，95%CI=1.97 至 12.76），但在更高暴露下下降。平均 REC 强度危险比上升到 32μg/m(3)左右的平台。在地表工人中也观察到了升高的危险比和暴露反应的证据。在模型中纳入其他与工作相关的潜在混杂暴露因素后，柴油废气暴露与肺癌风险之间的关联仍然存在，并且对暴露推导的替代方法具有稳健性。
研究结果提供了进一步的证据，表明接触柴油废气会增加肺癌死亡的风险，并具有重要的公共卫生意义。
