Indoor and Outdoor NO2 and Asthma Severity in Children

描述(由申请人提供)：暴露于空气过敏原和空气污染物被认为是哮喘恶化的主要因素。我们正在进行的研究结果表明，与使用燃气用具有关的室内二氧化氮(NO2)和与机动车排放的室外二氧化氮(NO2)远低于美国环保署空气质量标准，可能与有患哮喘风险的儿童的呼吸道症状有关，也可能与哮喘儿童的哮喘加重有关。我们的数据也暗示了室内空气过敏原和NO2浓度之间的相互作用，从而增强了婴儿和哮喘儿童的呼吸道症状。潜在的影响是巨大的，因为美国57%的家庭使用天然气或液化石油气，交通量正在增加，而且几乎所有家庭都有显著的粉尘过敏原水平。我们提出了一项针对1,533名活动期哮喘儿童(5至10岁)的前瞻性流行病学研究，以检验仔细量化与室内来源和州际公路上的车辆交通相关的NO2浓度与哮喘严重程度相关的假设。此外，我们将确定在存在常见室内粉尘变应原(Der p 1、Der f 1、Bla g 1、Pel d 1、Can f 1和真菌)的情况下，家庭中的NO2水平是否与对这些过敏原敏感的儿童哮喘严重程度的风险增加有关。上述假设将被评估，同时调整已知或怀疑会增加更严重哮喘风险的因素，包括家庭和学校特征。研究人群将从康涅狄格州16个城镇的小学中抽取，使用修改后的艾萨克问卷来确定患有活动性哮喘的儿童。最初的危险因素将在家庭访谈中评估，以及哮喘严重程度(症状、急诊室就诊频率、用药情况、肺功能)。将通过电话面谈进行为期一年的前瞻性评估，每季度进行一次。在家访中，将收集粉尘样本用于过敏原和真菌检测，并收集血液样本用于抗原特异性IgE检测。每个家庭的室内和室外NO2水平将按季度获得。全球信息系统将与道路车辆密度数据相结合，用于评估交通对哮喘严重程度和家庭室外NO2浓度的影响。家庭燃气用具和与交通相关的污染可能是哮喘儿童的重要环境暴露，为此可以制定有效的干预措施，以减少哮喘发病率。

DESCRIPTION (provided by applicant): Exposure to aeroallergens and air contaminants is hypothesized to be a major factor in the exacerbation of asthma. Results of our ongoing studies suggest that nitrogen dioxide (NO2) associated indoors with gas appliance use and outdoors with motor vehicle emissions, at levels well below the EPA Air Quality Standard, may be associated with respiratory symptoms in children at risk for developing asthma and with the exacerbation of asthma in asthmatic children. Our data are also suggestive of an interaction between indoor aeroallergens and NO2 concentrations in enhancing respiratory symptoms in infants and asthmatic children. The potential impact is great since 57% of homes in the US use natural or LP gas, traffic volume is increasing and virtually all homes have significant dust allergen levels. We propose a prospective epidemiologic study of 1,533 children with active asthma (5 to 10 years of age), to test the hypothesis that carefully quantified NO2 concentrations associated with indoor sources and vehicle traffic on state and interstate roads are associated with asthma severity. In addition, we will determine if home levels of NO2, in the presence of common indoor dust allergens (Der p 1, Der f 1, Bla g 1, Pel d 1, Can f 1 and fungi), are associated with an increased risk of asthma severity in children sensitized to those allergens. The above hypotheses will be evaluated while adjusting for factors known or suspected to increase risk of more severe asthma, including household and school characteristics. The study population will be drawn from elementary schools in 16 Connecticut towns using a modified version of the ISAAC questionnaire to identify children with active asthma. Initial risk factors will be assessed in a home interview, and asthma severity (symptoms, frequency of ER visits, medication use, lung function.) will be assessed prospectively for one year using telephone interviews administered quarterly. At the home visit, dust samples will be collected for allergen and fungi determinations and blood samples collected for antigen specific IgE determinations. Indoor and outdoor NO2 levels will be obtained quarterly for each home. Global Information Systems in combination with road vehicle density data will be used to assess the impact of traffic on asthma severity and outdoor NO2 concentrations at the home. Household gas appliances and traffic-related pollution may represent important environmental exposures for asthmatic children, for which effective interventions can be developed to reduce asthma morbidity.