Role of Diesel and Other Vehicular Exhaust in Exacerbation of Childhood Asthma

描述（由申请人提供）：儿童哮喘的负担不成比例地影响着生活在贫困地区和城市中心的儿童，其中许多是少数民族。对于那些生活在交通密度高的城市环境中的人来说，越来越多的人担心接触柴油和其他车辆尾气对呼吸健康的潜在不利影响。流行病学研究表明，暴露于高交通量，特别是高卡车交通量（城市环境中柴油废气的主要来源）与哮喘症状增加、哮喘住院和肺功能下降之间存在关联。然而，由于将柴油从火花点火废气中分离出来，以及将汽车尾气从其他污染源中分离出来的挑战，暴露于柴油和其他汽车尾气与不良呼吸健康结果之间的定量关联尚未得到很好的表征。本研究将描述与汽车尾气和其他特定空气污染源相关的环境暴露，并评估这些暴露与密歇根州底特律和迪尔伯恩儿童哮喘恶化的关系。我们将收集环境和室内家庭空气质量数据，提供污染浓度的高时间和空间分辨率，并利用最先进的统计/地理空间模型来分摊包括柴油和其他车辆尾气在内的污染源的暴露程度，并制定个人特定的暴露估计。我们将进行一项为期两年的纵向研究，涉及210名哮喘儿童，其中70名儿童居住在高交通/高卡车量道路附近，高交通/低卡车量道路附近，远离高交通道路。8个季节中每个季节连续两周评估的日常健康措施将包括呼吸道症状、用手持式肺活量计评估的肺功能、药物使用情况和保健服务利用情况。我们假设：1)与其他污染源相比，暴露于柴油和其他汽车尾气将更有力地预测生活在交通密度高的城市环境中的哮喘儿童的不良健康状况；2)家庭中存在吸烟者，家庭灰尘中常见过敏原含量高，或对此类过敏原敏感；将产生更强的暴露反应关系之间的柴油和其他车辆尾气和不利的呼吸健康结果。

DESCRIPTION (provided by applicant): The burden of childhood asthma disproportionately affects children living in poverty and in urban centers, many of whom are minority ethnic groups. For those living in urban environments with high traffic densities, there is increasing concern about potential adverse respiratory health effects of exposure to diesel and other vehicular exhaust. Epidemiologic studies have shown associations between exposure to high traffic volumes, and especially to high truck traffic - the main source of diesel exhaust in urban settings - and increases in asthma symptoms, asthma hospitalizations, and decreased lung function. Yet, owing to the challenges of separating diesel from spark ignition exhaust, and vehicular exhaust in general from other sources of pollution, quantitative associations between exposure to diesel and other vehicular exhaust and adverse respiratory health outcomes have not been well-characterized. This study will characterize ambient exposures related to vehicular exhaust and other specific air pollutant sources, and evaluate the relationship of these exposures to the exacerbation of asthma among children living in Detroit and Dearborn, Michigan. We will collect ambient and indoor household air quality data which provides both high temporal and spatial resolution of pollution concentrations and utilize state-of-the-art statistical/geospatial models to apportion exposures among pollutant sources including diesel and other vehicular exhaust and to develop individual- specific exposure estimates. We will conduct a two-year longitudinal study involving 210 asthmatic children with 70 each living near high traffic/high truck volume roads, near high traffic/low truck volume roads, and distant from high traffic roads. Daily health measures to be assessed for two consecutive weeks in each of eight seasons will include respiratory symptoms, pulmonary function assessed by hand-held spirometers, medication use, and health services utilization. We hypothesize that: 1) exposures specific to diesel and other vehicular exhaust will be stronger predictors of adverse health status among children with asthma living in a high traffic density urban environment than other pollutant sources, and, 2) the presence of cigarette smokers in the household, high levels of common allergens in household dust, or sensitization to such allergens, will yield stronger exposure-response relationships between diesel and other vehicular exhaust and adverse respiratory health outcomes.