Asthma Severity in Children & Fine Particle Composition

描述（由申请人提供）：环境细颗粒物质（< 2.5 |j，m直径[PM2]）。[S])被认为是哮喘恶化的一个因素。目前美国环保署对细颗粒物的标准可能无法保护敏感的亚群体——患有哮喘的儿童。关于颗粒接触对健康影响的少数横断面和小组研究存在许多局限性，包括：受试者人数少，哮喘严重程度范围窄，观察时间范围窄，无法控制家庭特征和过敏状况，关于颗粒（化学形态和来源）的信息有限，以及对气态共污染物的控制不佳。我们最近完成了一项为期1年的前瞻性随访研究，研究对象是居住在新英格兰南部的466名经医生诊断患有哮喘的儿童，该地区包括一个未达到EPA标准的地区。利用我们的儿童哮喘研究数据和有限的、可公开获得的PM2.5化学成分数据进行的初步分析表明，暴露于PM2.5的特定成分会损害日常呼吸健康。在这项拨款申请中，我们建议从我们地区的EPA监测点获取和分析储存的细颗粒收集过滤器，以获取微量元素和元素碳。我们进一步建议利用我们的儿童哮喘研究中158,000受试者日的症状和药物使用数据来检查暴露于PM2.5及其成分对呼吸健康的影响。主要健康结果是：母亲报告的每日呼吸症状（喘息、持续咳嗽、胸闷和呼吸短促）和药物使用情况；每月哮喘严重程度，使用全球哮喘倡议（GINA）指南进行评估。关联将通过纵向重复测量分析进行评估，使用广义估计方程以及考虑到暴露变异性来源的经验贝叶斯方法。气体共污染物、气象变量和潜在的混杂因素（一年中的季节、儿童的特应性疾病状况、当地交通密度）也将包括在评估中。相关性：本研究的结果将为评估EPA PM2.5标准的充分性提供必要的重要信息，可以识别PM2的成分。S对呼吸系统健康的影响最大，并可能为针对污染源的空气污染干预措施带来更具成本效益的战略。

DESCRIPTION (provided by applicant): Ambient fine particle matter (< 2.5 |j,m in diameter [PM2.s]) is hypothesized to be a factor in the exacerbation of asthma. The current US EPA standard for fine particles may not protect a sensitive sub-group-children with asthma. Limitations in the few cross-sectional and panel studies of the health effects of particle exposure are numerous and include: small subject numbers, narrow range of asthma severity, narrow time frame of observation, no control for household characteristics and allergic status, limited information on particles (chemical speciation and sources), and poor control of gaseous co-pollutants. We recently completed a prospective, 1-year follow-up study of 466 physician-diagnosed asthmatic children residing in southern New England, a region that includes an area of non-attainment of the EPA standard. Preliminary analysis using data from our Childhood Asthma Study and using limited, publicly available data on chemical constituents of PM2.5, suggests that daily respiratory health is compromised by exposure to particular components of PM2.s. In this grant application, we propose to acquire and analyze the stored, fine-particle collection filters from EPA monitoring sites in our region for trace elements and elemental carbon. We further propose to take advantage of the 158,000 subject-days of symptom and medication use data from our Childhood Asthma Study to examine the impact of exposure to PM2.5 and PM2.5 constituents on respiratory health. The primary health outcomes are: mother-reported daily respiratory symptoms (wheeze, persistent cough, chest tightness and shortness of breath) and medication use; and monthly asthma severity, assessed using the Global Initiative for Asthma (GINA) guidelines. Associations will be assessed with longitudinal repeated measures analyses using generalized estimating equations as well as empirical Bayes methods that will take into account sources of variability of exposures. Gaseous co-pollutants, meteorological variables and potential confounders (season of the year, atopic status of the child, local traffic density) will also be included in the evaluation. Relevance: Results of this study will provide important information necessary to assess the adequacy of the EPA PM2.5 standard, could identify the component(s) of PM2.s having the strongest impact on respiratory health, and could lead to more cost-effective strategies for source-targeted air-pollution interventions.