From the Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, CA.
Surveillance Branch, Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, WV.
Epidemiology. 2019 Mar;30(2):177-185. doi: 10.1097/EDE.0000000000000954.
Although general population studies of air pollution suggest that particulate matter-diesel exhaust emissions in particular-is a potential risk factor for cardiovascular disease, direct evidence from occupational cohorts using quantitative metrics of exposure is limited. In this study, we assess counterfactual risk of ischemic heart disease (IHD) mortality under hypothetical scenarios limiting exposure levels of diesel exhaust and of respirable mine/ore dust in the Diesel Exhaust in Miners Study cohort.
We analyzed data on 10,779 male miners from 8 nonmetal, noncoal mines-hired after diesel equipment was introduced in the respective facilities-and followed from 1948 to 1997, with 297 observed IHD deaths in this sample. We applied the parametric g-formula to assess risk under hypothetical scenarios with various limits for respirable elemental carbon (a surrogate for diesel exhaust), and respirable dust, separately and jointly.
The risk ratio comparing the observed risk to cumulative IHD mortality risk at age 80 under a hypothetical scenario where exposures to elemental carbon and respirable dust are eliminated was 0.79 (95% confidence interval [CI]: 0.64, 0.97). The corresponding risk difference was -3.0% (95% CI: -5.7, -0.3).
Our findings, based on data from a cohort of nonmetal miners, are consistent with the hypothesis that interventions to eliminate exposures to diesel exhaust and respirable dust would reduce IHD mortality risk.
尽管一般人群的空气污染研究表明，颗粒物——尤其是柴油废气排放——是心血管疾病的潜在危险因素，但使用暴露定量指标的职业队列的直接证据有限。在这项研究中，我们评估了矿工柴油机排气研究队列中假设限制柴油机排气和可吸入矿/矿石粉尘暴露水平的情况下，缺血性心脏病（IHD）死亡率的替代风险。
我们分析了来自 8 个非煤矿、非煤矿的 10779 名男性矿工的数据——这些矿工是在各自设施引入柴油机设备后被雇佣的——从 1948 年到 1997 年进行随访，在这个样本中观察到 297 例 IHD 死亡。我们应用参数 g 公式来评估各种限制可吸入元素碳（柴油机废气的替代品）和可吸入粉尘的假设情景下的风险，分别和联合。
与假设情景下的观察风险相比，观察到的风险与累积 IHD 死亡率风险在 80 岁时的风险比为 0.79（95%置信区间[CI]：0.64，0.97）。相应的风险差异为-3.0%（95% CI：-5.7，-0.3）。
我们的研究结果基于非煤矿工队列的数据，与干预措施消除柴油机排气和可吸入粉尘暴露将降低 IHD 死亡率风险的假设一致。
