HAFTRAP-Home Air Filtration for Traffic-Related Air Pollution

摘要 在主要道路和高速公路附近，超细颗粒物(UFP)浓度升高。证据是 强烈认为生活在这些地区与严重的呼吸系统、心血管和其他不良反应有关 健康结果。我们提供了最近的证据，证明长期接触UFP与 和心血管疾病风险。事实上，为了回应这些发现，包括我们在内，越来越多的人使用 室内空气过滤，以减少高速公路附近家庭和学校的交通相关污染水平，包括 以市场为基础的回应和城市条例。然而，到目前为止，还没有经验证据表明这些 这些措施可以改善健康状况。这项建议建立在初步研究的基础上，在这些初步研究中，我们进行了随机 室内空气过滤在较小规模(N=20和23)和受控短期环境下的交叉试验 77例。我们的随机2小时暴露研究表明，通过过滤减少PM可以降低血液 压力。因此，我们提出了一项盲法随机交叉疗效试验(N=240户 由288名参与者组成)在近公路家庭中进行高效颗粒物空气(HEPA)过滤， 缺乏机械空气处理系统。家庭将随机接受30天的过滤或假手术 过滤，然后是30个洗涤期，然后是30天的替代分配。 每个家庭的卧室和起居室都将安装商用的房间空气过滤器。 我们将在过滤和假期间测量20%的家庭中的UFP和PM2.5浓度，并 评估部分参与者的个人暴露情况。我们还将评估颗粒物的化学成分 10个家庭/年的空气污染用于探索性目的，这可能导致未来的研究路线。我们的初选 健康终点将是参与者的hsCRP和外周血压，我们在 UFP的多项观察性研究以及我们的先导性过滤干预研究。次生生物学 有助于理解生物途径的措施将是IL-6(炎症)、D-二聚体 (凝血)、代谢物、中心压和动脉僵硬。治疗分析的主要目的是 比较HEPA过滤和假过滤的结果。我们将有80%的力量来检测差异 0.6 mg/L的超敏C反应蛋白变化与收缩压下降3.5毫米汞柱的差值 与没有接受过滤的参与者相比。将参与者作为自己的控件在 干预效果的受试者内比较增加了我们的统计能力，消除了 人口统计学和临床特征中基线失衡的可能性。一项社会科学评估将 在开始时通知对我们方法的最终调整，并评估参与者的接受度和经验 随着干预行动的结束。我们的主要创新是这将是第一个接近高速公路HEPA 规模足够大、足够谨慎，足以与政策相关的干预试验。

Abstract Concentrations of ultrafine particles (UFP) are elevated near major roadways and highways. Evidence is strong that living in these areas is associated with substantial respiratory, cardiovascular and other adverse health outcomes. We have contributed to recent evidence of associations between chronic exposure to UFP and cardiovascular disease risk. Indeed, in response to these findings, including ours, there is growing use of in-building air filtration to reduce traffic-related pollution levels in homes and schools near highways, including market-based responses and city ordinances. There is, however, as yet, no empirical evidence that these measures improve health. This proposal builds on preliminary studies in which we conducted randomized crossover trials of in-home air filtration on a smaller scale (N= 20 and 23) and a controlled short term setting (N=77). Our randomized 2-hour exposure study showed that reducing PM with filtration can reduce blood pressure. Accordingly, we propose a blinded randomized crossover efficacy trial (N=240 households consisting of 288 participants) of High Efficiency Particulate Air (HEPA) filtration in near-highway homes that lack mechanical air-handling systems. Households will be randomized to 30 days of either filtration or sham filtration followed by a 30 washout period with a subsequent 30-day period of the alternative assignment. Room air filters that are commercially available will be placed in the bedroom and living room of each home. We will measure UFP and PM2.5 concentrations in 20% of the homes during filtration and sham periods and assess personal exposure in a subset of participants. We will also assess chemical composition of particulate air pollution in 10 homes/year for exploratory purposes that could lead to future lines of research. Our primary health endpoints will be participants’ hsCRP and peripheral blood pressure, measures we have used in multiple observational studies of UFP as well as in our pilot filtration intervention studies. Secondary biological measures that contribute to understanding biological pathways will be IL-6 (inflammation), D-dimer (coagulation), metabolome, central pressure and arterial stiffness. The primary intention to treat analysis will compare outcomes between HEPA filtration to sham filtration. We will have 80% power to detect a difference of 0.6 mg/L in change in hsCRP and a difference in reduction in systolic blood pressure of 3.5 mmHg compared to participants who receive no filtration. Having participants serve as their own controls in the within-subject comparisons of intervention effectiveness increases our statistical power and eliminates the possibility of baseline imbalances in demographic and clinical characteristics. A social science evaluation will inform final adjustments to our approach at the start and also assess participant acceptance and experience with the intervention at the end. Our primary innovation is that this will be the first near highway HEPA intervention trial that is large enough and careful enough to be policy-relevant.