Indoor Nitrogen Dioxide Exposure and Children with Asthma: An Intervention Trial

室内二氧化氮暴露与哮喘儿童：一项干预试验

基本信息

批准号：
8759108
负责人：
MICHAEL B BRACKEN
金额：
$ 99.4万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-11 至 2019-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8759108
关键词：
11 year old Affect Air Air Pollutants Allergens Asthma Blinded Calendar Child Chronic Clinical Trials Data Monitoring Committees Clinical Trials Design Data Devices Disease Double-Blind Method Enrollment Ensure Epidemiologic Studies Exposure to Family Frequencies Gases Genetic Crossing Over Guidelines Heating Home environment Household Housing Infiltration Intervention Intervention Studies Intervention Trial Left Life Measurement Measures Medical Minority Molds Monitor Morbidity - disease rate Natural Gas Nitrogen Dioxide Outcome Study Particulate Matter Pharmaceutical Preparations Phase III Clinical Trials Prevalence Protocols documentation Public Health Randomized Reproduction spores Research Research Training Respiratory physiology Services Severities Shapes Source Spirometry Study Subject Symptoms Testing Urban Population Weight clinically relevant clinically significant cooking data management design foot inner city innovation particle public health relevance remediation residence respiratory suburb trafficking treatment duration ultrafine particle urban area

项目摘要

DESCRIPTION (provided by applicant): Asthma and reactive airway disease are the most common chronic medical conditions in children and affect over 7 million in the US alone. Asthma prevalence tends to be highest in inner cities and has a disproportionate impact on minorities. Adverse respiratory effects in children with asthma are associated with exposures to nitrogen dioxide (NO2) - an air pollutant with both indoor and outdoor sources. Principal indoor sources include gas stoves as well as other gas appliances, natural gas-fueled home heating, and infiltration from outdoor sources (e.g., traffic). Over one-third of US households use gas for cooking, and in homes with sources, highest indoor NO2 concentrations are found in inner-city residences where gas service is common and house volumes are smaller compared to suburban homes. Data from epidemiologic studies indicate that a reduction in NO2 concentrations commonly encountered in urban homes would result in a clinically significant reduction in asthma severity. We propose a randomized, double-blind, triple cross-over intervention study to examine the efficacy of substantial reduction of indoor NO2 on reducing asthma severity. To carry out an optimal Phase III clinical trial (randomized, double-blind, cross-over), we have designed an air cleaning device to accommodate each one of three filter types: (1) an NO2 scrubber composed of a filter that removes 80% of NO2 and also 80% of particles; (2) a nanofilter that removes all suspended particulate matter > 0.12 ¿m (but removes less than 10% of the NO2); and (3) a "control" that filters neither NO2 nor particles. We propose to enroll 600 asthmatic children between 5-11 years of age living in homes with gas stoves and high NO2 levels and to randomly allocate them to a sequence of three experimental home interventions over a 16-week period while following them to assess asthma severity. Pilot testing suggests that two air cleaning devices operating at flow rates on the order of 450 cubic feet per minute, each with the NO2 scrubber in place, will ensure reductions in NO2 in a modest-sized home on the order of 90% or greater. The primary study outcome is a 5-level asthma severity score (Global Initiative for Asthma guidelines), calculated using symptoms, asthma medication use (recorded on calendars) and spirometry-assessed lung function (using NIOSH-certified, trained research assistants). The research aims are: (1) Determine whether reducing exposure to NO2 and particles compared to a "control" (non-filtered) condition results in a clinically significant reduction in asthma severity by one or more levels; and (2) Determine whether reducing exposure to particles > 0.12 ¿m alone (without concurrent reduction in NO2) similarly reduces asthma severity. We focus recruitment efforts on asthmatic children from urban families most likely to have high indoor levels of NO2 (e.g., families with gas stoves living in multifamily housing). If trial results indicate that children with asthma would benefit from a reduction in exposure to indoor NO2, practical and economical remediation strategies are readily available.

描述（由申请人提供）：哮喘和反应性气道疾病是儿童中最常见的慢性疾病，仅在美国就影响了超过 700 万人。哮喘患病率往往在内城区最高，对少数族裔的影响尤为严重。哮喘儿童的影响与二氧化氮 (NO2) 的接触有关，二氧化氮是一种室内和室外的空气污染物，主要室内来源包括煤气炉以及其他燃气器具、天然气燃料的家庭供暖和空气污染物。超过三分之一的美国家庭使用天然气进行烹饪，而在有天然气来源的家庭中，室内二氧化氮浓度最高的地方是燃气服务普遍且房屋体积较小的内城住宅。流行病学研究的数据表明，城市家庭中常见的二氧化氮浓度降低将导致哮喘严重程度在临床上显着降低，我们建议进行一项随机、双盲、三重交叉干预研究来检验其疗效。大幅减少为了进行最佳的 III 期临床试验（随机、双盲、交叉），我们设计了一种空气净化装置，以适应三种过滤器类型中的每一种：(1) NO2。洗涤器由过滤器组成，可去除 80% 的 NO2 和 80% 的颗粒物；(2) 纳米过滤器，可去除所有 > 0.12 的悬浮颗粒物； m（但去除的二氧化氮不到 10%）；以及（3）既不过滤二氧化氮也不过滤颗粒物的“对照”。我们建议招募 600 名居住在有燃气灶和高温的家庭中的哮喘儿童。 NO2 水平，并在 16 周内将其随机分配到一系列实验性家庭干预中，同时跟踪它们以评估哮喘严重程度，试点测试表明，两个空气净化设备的运行流量约为 450。每分钟立方英尺，如果安装了二氧化氮洗涤器，将确保中等规模的家庭中二氧化氮的减少量达到 90% 或更高。主要研究结果是 5 级哮喘严重程度评分（全球哮喘倡议）。指南），使用症状、哮喘药物使用（记录在日历上计算）和肺功能评估肺功能（使用 NIOSH 认证、训练有素的研究助理）。研究目的是：（1）确定是否减少。与“对照”（未过滤）条件相比，暴露于 NO2 和颗粒会导致哮喘严重程度临床显着降低一个或多个水平；以及 (2) 确定是否减少颗粒暴露 > 0.12 ¿单独使用 m（不同时减少 NO2）同样可以降低哮喘严重程度，我们将招募工作重点放在最有可能室内 NO2 水平较高的城市家庭（例如，居住有燃气灶的家庭）的哮喘儿童上。如果试验结果表明哮喘儿童可以从减少室内二氧化氮暴露中获益，那么实用且经济的补救策略是现成的。