BACKGROUND Evidence suggests that long-term exposure to air pollution may increase the risk of dementia and related cognitive outcomes. A major source of air pollution is automotive traffic, which is modifiable by technological and regulatory interventions. OBJECTIVES We examined associations of four traffic-related air pollutants with rates of cognitive decline in a cohort of older adults. METHODS We analyzed data from the Chicago Health and Aging Project (CHAP), a longitudinal (1993-2012) community-based cohort study of older adults that included repeated assessments of participants' cognitive performance. Leveraging previously developed air pollution models, we predicted participant-level exposures to the tailpipe pollutants oxides of nitrogen (NOX) and nitrogen dioxide (NO2), plus the nontailpipe pollutants copper and zinc found in coarse particulate matter [PM with aerodynamic diameter 2.5μm to 10μm (PM2.5-10,Cu) and PM2.5-10,Zn, respectively], over the 3 y prior to each participant's baseline assessment. Using generalized estimating equations, we estimated covariate-adjusted associations of each pollutant with rates of cognitive decline. We probed the robustness of our results via several sensitivity analyses, including alterations to the length of the exposure assessment window and exploring the influence of pre- and post-baseline selection bias. RESULTS Using data from 6,061 participants, estimated associations of these pollutant exposures with cognitive decline were largely inconsistent with large adverse effects. For example, a standard deviation (5.8 ppb) increment in NOX corresponded to a slightly slower rate of cognitive decline [e.g., mean difference in change in global score, 0.010 standard unit/5 y, 95% confidence interval (CI): -0.016, 0.036]. The results of most of our sensitivity analyses were in generally similar to those of our main analyses, but our prebaseline selection bias results suggest that our analytic results may have been influenced by differential survivorship into our study sample. DISCUSSION In this large prospective cohort study, we did not observe compelling evidence that long-term TRAP exposure is associated with cognitive decline. https://doi.org/10.1289/EHP14585.

中文翻译：

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芝加哥健康与老龄化项目中尾气相关和非尾气相关空气污染暴露与认知能力下降的关联。


有证据表明，长期暴露在空气污染中可能会增加患痴呆的风险和相关认知结果。空气污染的一个主要来源是汽车交通，这可以通过技术和监管干预来改变。目的 我们检查了四种与交通相关的空气污染物与一组老年人认知能力下降率的关联。方法 我们分析了芝加哥健康与老龄化项目 （CHAP） 的数据，这是一项针对老年人的纵向 （1993-2012） 基于社区的队列研究，其中包括对参与者认知表现的重复评估。利用先前开发的空气污染模型，我们预测了参与者层面对粗颗粒物中发现的尾气污染物氮氧化物 （NOX） 和二氧化氮 （NO2），以及粗颗粒物中发现的非尾气污染物铜和锌的暴露 [空气动力学直径分别为 2.5μm 至 10μm（PM2.5-10，Cu）和 PM2.5-10，Zn]，在每个参与者基线评估之前的 3 年内]。使用广义估计方程，我们估计了每种污染物的协变量调整与认知能力下降率的关联。我们通过几项敏感性分析来探索结果的稳健性，包括改变暴露评估窗口的长度，并探索基线前和基线后选择偏倚的影响。结果使用来自 6,061 名参与者的数据，估计这些污染物暴露与认知能力下降的关联在很大程度上与较大的不利影响不一致。例如，NOX 的标准差 （5.8 ppb） 增量对应于认知能力下降的速度略慢 [例如，整体评分变化的平均差异，0.010 标准单位/5 y，95% 置信区间 （CI）：-0.016,0.036]。 我们大多数敏感性分析的结果与我们的主要分析的结果基本相似，但我们的基线前选择偏倚结果表明，我们的分析结果可能受到研究样本中生存率差异的影响。讨论 在这项大型前瞻性队列研究中，我们没有观察到令人信服的证据表明长期 TRAP 暴露与认知能力下降有关。https://doi.org/10.1289/EHP14585。