Potential Inhaled Dose of Particulates, Biking and Cardiovascular Indicators

描述(由申请人提供)：这项研究项目有两个总体目标：(A)验证一种新的个人水平方法来评估潜在的颗粒物空气污染吸入剂量；(B)评估该方法对空气污染流行病学中的一个重要主题，即在接近空气污染源的情况下短期暴露于空气中对心血管的急性影响。在这个项目中，我们将重点关注骑自行车作为一种锻炼形式，它带来了许多好处--增加锻炼，减少道路拥堵，减少温室气体排放--但对于那些选择骑自行车而不是其他交通工具的人来说，它可能会增加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央站点数据的不完美的替代指标，尽管环境浓度不能很好地预测个人暴露。到目前为止，个人暴露研究被视为黄金标准，但有两个主要限制--(A)它们没有考虑体积呼吸率的变化，(B)大规模个人研究过于繁重。这个应用程序将专注于克服第一个限制并最小化第二个限制。我们将进行成本效益分析，对改进的指标和方案如何减少研究所需的规模和成本进行一些量化估计。空气污染物的实际吸入剂量是由高呼吸频率和峰值暴露的时间重叠驱动的，因此也是身体活动模式和来源接近的时间重叠。我们建议在当前研究中验证和部署的主要设备是RTI MicroPEM“主要是由早期基因环境倡议资金开发的。我们将使用MicroPEM的板载加速度计来估计每分钟的通气率(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结合起来计算潜在的吸入剂量(以微克/分钟为单位)。该项目的验证阶段将侧重于改进根据加速度计数据预测微小通气量的方法，并验证PM2.5测量结果，并在实验室和现场进行预测试。该项目的第二阶段将需要在一群城市骑自行车的人中部署微型质子交换膜，这些人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在空气中的逐日变化，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。这项拟议的工作建立在哥伦比亚大学和美国最大的公共广播电台WNYC之间的合作基础上，一个由哥伦比亚大学环境健康科学家、心脏病专家和暴露评估专家组成的团队，以及开发MicroPEM设备的RTI团队的核心成员参与其中。

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.