Potential Inhaled Dose of Particulates, Biking and Cardiovascular Indicators

描述（由申请人提供）：本研究项目有两个总体目标：（a）验证一种新的个人水平方法，以评估颗粒空气污染的潜在吸入剂量;以及（B）评估该方法对空气污染流行病学中的一个重要主题的影响，即在空气污染源附近运动时短期暴露对心血管的急性影响。在这个项目中，我们将把重点放在骑自行车作为一种锻炼方式上，它带来了许多好处-增加锻炼，减少道路拥堵和减少温室气体排放-但它可能会增加那些选择骑自行车而不是其他交通方式的人对空气污染的暴露和剂量。可靠的暴露评估是空气污染流行病学的必要条件，但历史上的研究都是基于中心站点数据的不完善的代理，即使环境浓度是个人暴露的不良预测因素。迄今为止，个人接触研究被视为黄金标准，但有两个主要局限性-（a）它们没有考虑到体积呼吸率的变化，（B）大规模进行个人研究过于繁琐。这个应用程序将工作重点克服第一个限制，并尽量减少第二个。我们将进行成本效益分析，对改进后的指标和方案如何减少研究所需的规模和成本进行定量估计。空气中污染物的实际吸入剂量是由高呼吸率和峰值暴露的时间重叠决定的，因此也是由身体活动模式和污染源接近程度决定的。我们建议在当前研究中验证和部署的主要设备是RTI MicroPEM，该设备主要由早期基因环境倡议资助开发。我们将使用MicroPEM的机载加速度计来估计每分钟通气量（每分钟吸入的空气量），并将此信息与每分钟的空气污染浓度相结合，以计算潜在的吸入剂量（微克/分钟）。该项目的验证阶段将侧重于改进从加速度计数据预测每分钟通气量的方法，并验证PM2.5测量结果，并在实验室和现场环境中进行预测试。该项目的第二阶段将在一群城市骑自行车的人中部署MicroPEM，他们还将配备测量黑碳暴露、动态血压和心率变异性的设备。利用早晨通勤期间暴露的每日变化，我们将估计短期空气污染暴露与急性心血管参数之间的关联。拟议的工作建立在哥伦比亚大学和全国最大的公共广播电台WNYC之间的合作关系基础上，涉及一个由哥伦比亚环境健康科学家，心脏病学家和暴露评估专家组成的团队，以及开发MicroPEM设备的RTI团队的核心成员。

DESCRIPTION (provided by applicant): This research project has two overall goals: (a) the validation of a new personal level approach to assessing potential inhaled dose of particulate air pollution; and (b) the assessment of this method to an important topic in air pollution epidemiology, namely the acute cardiovascular impacts of short term exposures while exercising in close proximity to air pollution sources. In this project we will focus on biking as he form of exercise, which brings many benefits - increased exercise, less roadway congestion and reduced greenhouse gas emissions - but it may cause increased exposures and doses to air pollution for those who choose biking over other transport modes. Reliable exposure assessment is the sine qua non of air pollution epidemiology, but studies have historically made do with imperfect proxies based on central site data, even though ambient concentrations are poor predictors of personal exposure. Personal exposure studies are seen as the gold standard to date but have had two major limitations- (a) they don't take into account variations in volumetric respiration rates, and (b) personal studies are overly burdensome to do on a large scale. This application will work focus overcoming the first limitation and on minimizing the second. We will carry out cost-benefit analyses to put some quantitative estimates on how the improved metrics and protocols can reduce the needed size and cost of studies. The actual inhaled dose of an airborne pollutant is driven by the temporal overlap of high respiration rates and peak exposures, and thus of physical activity patterns and source proximity. The primary device that we propose to validate and deploy in the current study is the RTI MicroPEM" primarily developed with early Gene Environment Initiative funding. We will use the MicroPEM's onboard accelerometer to estimate the minute ventilation rate (the volume of air inhaled per minute) and combine this information with minute-by-minute air pollution concentrations to calculate potential inhaled dose (in micrograms/minute). The validation phase of the project will focus on improving methods for predicting minute ventilation from accelerometer data and validating PM2.5 measurements, with pretesting in lab and field settings. The second phase of the project will entail deploying MicroPEMs in a cohort of urban cyclists, who will also be outfitted with devices to measure black carbon exposures, ambulatory blood pressure and heart rate variability. Using day-to-day variation in exposures during the morning commute, we will estimate the association between short-term air pollution exposures and acute cardiovascular parameters. The proposed work builds on a partnership between Columbia University and WNYC, the nation's largest public radio station and involves a team comprising Columbia environmental health scientists, cardiologists, and exposure assessment experts, and core members of the RTI team that developed the MicroPEM device.