HAFTRAP-Home Air Filtration for Traffic-Related Air Pollution

摘要 超细颗粒（UFP）的浓度在主要道路和高速公路附近升高。证据 强烈认为，生活在这些地区与大量的呼吸，心血管和其他不利 健康成果。我们最近提供的证据表明，长期暴露于超微粒子 和心血管疾病风险。事实上，为了回应这些发现，包括我们的发现，越来越多的人使用 室内空气过滤，以减少高速公路附近的家庭和学校的交通相关污染水平，包括 基于市场的反应和城市法令。然而，目前还没有经验证据表明， 措施改善健康。这项建议建立在我们进行随机分组的初步研究的基础上， 在较小规模（N= 20和23）和受控短期环境下进行的家庭空气过滤交叉试验 （N=77）。我们的随机2小时暴露研究表明，通过过滤减少PM可以减少血液 压力因此，我们提出了一个盲随机交叉疗效试验（N=240户 由288名参与者组成），在高速公路附近的家庭中进行高效颗粒空气（HEPA）过滤， 缺少机械空气调节系统。家庭将被随机分配到30天的过滤或假手术组 过滤，然后是30天的洗脱期，随后是30天的替代分配期。 市售的室内空气过滤器将放置在每个家庭的卧室和客厅。 我们将在过滤和假过滤期间测量20%的家庭中的UFP和PM2.5浓度， 评估参与者子集中的个人暴露。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，可能导致未来的研究方向。我们的首要 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初步滤过干预研究。二级生物 有助于理解生物学途径的措施将是IL-6（炎症），D-二聚体 （凝血）、代谢组、中心压和动脉僵硬度。治疗分析的主要目的是 比较HEPA过滤与假过滤之间的结果。我们将有80%的能力检测出 hsCRP变化0.6 mg/L，收缩压降低3.5 mmHg 与没有接受过滤的参与者相比。让参与者在 干预有效性的受试者内比较增加了我们的统计能力，并消除了 人口统计学和临床特征基线失衡的可能性。社会科学评价将 在一开始就对我们的方法进行最终调整，并评估参与者的接受程度和经验 最后的干预。我们的主要创新是，这将是第一个近高速公路HEPA 干预试验规模足够大，足够仔细，与政策相关。

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.