The Commuter Exposure Study: Linking Exposure, Source-Receptor Models, and Health

描述（由申请人提供）：机动车辆排放有毒化学物质的复杂混合物，这在很大程度上造成了这个国家的空气污染负担。虽然已证明环境空气污染与心肺影响之间存在一致的联系，但关于交通相关空气污染（特别是在通勤期间）的暴露和健康影响的知识却很少。即使在空气污染本底水平较低的社区，通勤期间也存在强烈的短期接触，可能对健康造成不利影响。在之前的空气污染研究中，健康的、经常锻炼的人群（比如骑自行车的人）一直被忽视。这些活动增加肺剂量的人群是通勤者中潜在的易感人群。因此，有必要提高我们对与交通有关的空气污染的来源、暴露和健康影响之间相互作用的理解。这项研究的目的是应用创新的建模和暴露评估和建模技术，以提高我们对与交通有关的空气污染对人类暴露和健康的影响的理解。为达致上述目标，我们建议以下具体目标：(1)进行一项为期两年的研究，研究通勤者在不同交通方式（汽车、自行车）和不同交通路线（高流量和低流量）下的个人交通相关空气污染暴露情况；(2)开发和评估一个暴露建模系统，该系统集成了机械空气污染命运和运输模型、路径跟踪暴露估计和贝叶斯更新；(3)评估早晨通勤期间个人暴露水平与亚临床呼吸和心血管反应的短期关系，这是将空气污染与心血管事件联系起来的假设生物学途径的核心。我们假设骑自行车的人（与汽车司机相比）和在高流量路线上（与低流量路线相比）的个人暴露于交通相关的空气污染的程度要高得多，并且我们的模型系统将成功预测通勤者在不同路线/模式组合下的平均累积暴露。我们还假设，通勤期间与交通相关的空气污染的个人暴露增加将与心血管和呼吸反应的急性增加（从上下班前到上下班后）有关。该项目解决了影响大多数美国人口的空气污染源暴露及其相关健康影响方面的知识差距。鉴于有关交通相关空气污染的不利影响的新证据，从本研究中获得的信息可以使公民减少日常接触与交通相关的空气污染。每天的通勤，无论是骑自行车、汽车还是其他方式，几乎是所有美国人的共同经历。虽然环境空气污染通常被认为是一种无处不在的非自愿危害，但开发新知识以减少通勤期间接触与交通有关的空气污染的研究有可能产生重大的公共健康影响。

DESCRIPTION (provided by applicant): Motor vehicles emit a complex mixture of toxic chemicals that contributes substantially to the burden of air pollution exposure in this country. While a consistent link between ambient air pollution and cardiopulmonary effects has been demonstrated, very little knowledge exists regarding exposures and health effects of traffic- related air pollution specifically during the commute. Even in communities with low background levels of air pollution, there are intense, short-term exposures during commutes that may contribute to adverse health effects. Healthy, exercising populations (such as cyclists) have been neglected in previous air pollution research. Such populations with activities that increase lung dose are a potentially vulnerable subgroup among commuters. Therefore, a need exists to improve our understanding of the interactions between sources, exposures, and health effects of traffic-related air pollution. The objective of this research is to apply innovative modeling and exposure assessment and modeling techniques to improve our understanding of the impact of traffic-related air pollution on human exposure and health. To achieve this objective we propose the following specific aims: (1) Conduct a two-year study of commuters' personal exposures to traffic-related air pollution among different modes (car, bike) and routes (high- and low-traffic); (2) Develop and evaluate an exposure modeling system that integrates mechanistic air pollution fate and transport modeling, path-following exposure estimation, and Bayesian updating; and (3) Evaluate the short-term association of personal exposure levels during morning commutes with subclinical respiratory and cardiovascular responses that are central to the hypothesized biologic pathway linking air pollution with cardiovascular events. We hypothesize that personal exposures to traffic-related air pollution will be significantly higher for cyclists (vs. car drivers) and on high-traffic routes (vs. low-traffic), and that our model system will successfully predict average cumulative exposures for commuters traveling different route/mode combinations. We also hypothesize that increased personal exposure to traffic-related air pollution experienced during a commute will be associated with acute increases (from pre- to post-commute) in cardiovascular and respiratory responses. This project addresses knowledge gaps on the exposures and related health effects of a source of air pollution that affects the majority of the U.S. population. Given the emerging evidence on the adverse effects of traffic- related air pollution, information gained from this study can empower citizens to reduce their daily exposures to traffic-related air pollution. The daily commute, whether by bicycle, motor vehicle, or other mode, is an experience shared by nearly all Americans. Although ambient air pollution is generally considered a ubiquitous, involuntary hazard, research that develops new knowledge to reduce exposures to traffic-related air pollution during commuting has the potential to produce a substantial public health impact.