Department of Civil and Environmental Engineering, Tufts University, Medford, MA, USA.
Bouvè College of Health Sciences, Northeastern University, Boston, MA, USA.
Environ Int. 2022 Jan 15;159:106988. doi: 10.1016/j.envint.2021.106988. Epub 2021 Dec 18.
Our understanding of the impact of long-term exposures to PM constituents and sources on mortality is limited.
To examine associations between long-term exposures to PM constituents and sources and cause-specific mortality in US older adults.
We obtained demographic and mortality data for 15.4 million Medicare beneficiaries living within the conterminous United States (US) between 2000 and 2008. We assessed PM constituents exposures for each beneficiary and used factor analysis and residual-based methods to characterize PM sources and mixtures, respectively. In age-, sex-, race- and site- stratified Cox proportional hazard models adjusted for neighborhood socio-economic status (SES), we assessed associations of individual PM constituents, sources, and mixtures and cause-specific mortality and examined modification of these associations by participant demographics and location of residence. We assessed the robustness of our findings to additional adjustment for behavioral risk factors and to alternate exposure definitions and exposure windows.
Hazard ratios (HR) were highest for all causes of death, except COPD, for PM constituents and the coal combustion-related PM components, with no evidence of confounding by behavioral covariates. We further found Pb and metal-related PM components to be significantly associated with increased HR of all causes of death, except COPD and lung cancer mortality, and nitrate (NO) and silicon (Si) and associated source-related PM components (traffic and soil, respectively) to be significantly associated with increased all-cause, CVD, respiratory and all cancer-related mortality HR. Associations for other examined constituents and mortality were inconsistent or largely null. Our analyses of mixtures were generally consistent with these findings. Mortality HRs were greatest for minority, especially Black, low-income urban, younger, and male beneficiaries.
PM components related to coal combustion, traffic, and to a lesser extent, soil were strongly associated with mortality from CVD, respiratory disease, and cancer.
我们对长期暴露于 PM 成分和来源对死亡率的影响了解有限。
在美国老年人中研究长期暴露于 PM 成分和来源与特定原因死亡率之间的关系。
我们获取了 2000 年至 2008 年间生活在美国大陆的 1540 万医疗保险受益人的人口统计学和死亡率数据。我们评估了每位受益人的 PM 成分暴露情况，并分别使用因子分析和基于残差的方法来描述 PM 来源和混合物。在年龄、性别、种族和地点分层的 Cox 比例风险模型中，我们调整了邻里社会经济地位 (SES)，评估了个体 PM 成分、来源和混合物与特定原因死亡率的关联，并检查了这些关联受参与者人口统计学和居住地点的影响。我们评估了我们的发现对额外调整行为风险因素以及替代暴露定义和暴露窗口的稳健性。
除 COPD 外，所有死因的 HR 均最高，与 PM 成分和煤燃烧相关的 PM 成分有关，行为协变量无混杂证据。我们还发现，Pb 和金属相关的 PM 成分与除 COPD 和肺癌死亡率外的所有死因死亡率的 HR 增加显著相关，硝酸盐 (NO) 和硅 (Si) 以及相关的源相关 PM 成分（分别为交通和土壤）与所有原因、心血管疾病、呼吸和所有癌症相关死亡率的 HR 增加显著相关。其他检查成分与死亡率的关联不一致或基本为零。我们对混合物的分析一般与这些发现一致。少数族裔，尤其是黑人、低收入城市、年轻和男性受益人的死亡率 HR 最高。
与煤燃烧、交通以及在较小程度上与土壤相关的 PM 成分与心血管疾病、呼吸疾病和癌症死亡率密切相关。
