Pediatric asthma, photochemical oxidant air pollutants, and climate change vulner

描述(申请人提供)：光化学氧化剂空气污染物，如臭氧(臭氧)，预计会随着全球变暖而增加。鉴于臭氧的已知影响，预计这将对哮喘儿童的健康产生重大影响。然而，关于二次有机气溶胶中的光化学氧化剂污染物的重要性的信息要少得多，在许多方面，这种污染物对呼吸健康的危害可能比环境中的臭氧更大。因此，单独使用臭氧很可能低估了全球变暖导致的光化学空气污染物增加对脆弱人群哮喘发病率的潜在影响。弱势群体可能包括有色人种儿童和社会经济地位较低的儿童。易受影响的人还包括那些生活在化石燃料燃烧初级产品(包括SOA前体)浓度较高的交通繁忙地区的人，或者生活在这些污染源所在地下风向、包括SOA在内的城市气溶胶浓度较高的炎热地区的人。我们假设，儿童每日哮喘发病率将与局部暴露于光化学氧化剂空气污染物的增加有关，与主要燃烧相关空气污染物的影响无关。此外，我们假设，在生活在社会经济地位较低的地区和生活在光化学空气污染较多的温暖地区的受试者中，这些联系将更加强烈。我们预计，随着未来气候变化和共同决定污染物浓度的潜在排放清单的变化，哮喘的风险将会增加。我们将使用四个目标来解决这些假设：我们将首先估计2000-2008年整个加利福尼亚州邮政编码水平的每日空气污染物暴露。空气污染物将包括环境测量的环保局监管的标准空气污染物。我们还将使用面向源的化学传输模型来估计邮政编码对臭氧、NO2、粒度分级颗粒物(包括SOA和主要污染物)和颗粒物来源的具体暴露。然后，我们将评估儿童因暴露在光化学氧化剂(SOA和臭氧)以及其他污染物中而急诊和入院治疗哮喘的风险。随后将评估可能代表脆弱性增加的主题和地理因素对关联性的影响修正。最后，我们将从全球变暖对光化学污染物水平的影响评估儿童哮喘发病的潜在未来风险，并根据假设的人口脆弱性进行分层。这项拟议的研究结合了最新的反应化学传输模型和最新的SOA形成理论，并在与气候相关的分析期间应用这些理论，以确定未来SOA浓度是否会因气候变化而发生重大变化。了解这一点对于全面评估气候变化对易受光化学氧化剂空气污染健康影响的特定人群的影响至关重要。

DESCRIPTION (provided by applicant): Photochemical oxidant air pollutants such as ozone (O3) are anticipated to increase with global warming. Given the known effects of O3, this is anticipated to have major impacts on the health of children with asthma. However, there is much less information about the importance of the photochemical oxidant pollutants in secondary organic aerosols (SOA), which in many respects have the potential to do greater harm to respiratory health than ambient O3. Therefore, the potential impact on asthma morbidity among vulnerable populations from photochemical air pollutant increases resulting from global warming is likely to be underestimated using O3 alone. Vulnerable populations may include children of color and those with low socioeconomic status. Vulnerable people also include those living in heavily trafficked regions with higher concentrations of primary products of fossil fuel combustion (which include SOA precursors), or people living downwind of these source sites in hotter regions with high concentrations of photochemically aged urban aerosols including SOA. We hypothesize that daily asthma morbidity in children will be associated with increased local exposures to photochemical oxidant air pollutants, independent of the effects of primary combustion-related air pollutants. Furthermore, we hypothesize that these associations will be stronger in subjects living in regions with lower socioeconomic status and in warmer regions with more photochemical air pollution. We anticipate that such risks of asthma will increase with future changes to climate and to the underlying emissions inventory that together determine pollutant concentrations. Four aims will be used to address these hypotheses: We will first estimate daily air pollutant exposures at the zip code level throughout the state of California for 2000-2008. Air pollutants will include ambient measurements of EPA-regulated criteria air pollutants. We will also employ a source-oriented chemical transport model to estimate zip-code specific exposures to O3, NO2, size-fractionated particle species (including SOA and primary pollutants) and particle sources. We will then assess the risk of emergency department visits and hospital admissions for asthma among children from local exposures to photochemical oxidants (SOA and O3), among other pollutants. This will be followed by an assessment of effect modification of associations by subject and geographic factors that may represent increased vulnerability. Finally, we will assess the potential future risk of pediatric asthma morbidity from the effects of global warming on photochemical pollutant levels, stratified by hypothesized population vulnerabilities. The proposed research combines a state-of-the-science reactive chemical transport model with the latest SOA formation theories and applies them over climatologically relevant analysis periods to determine if SOA concentrations will experience significant changes in the future due to climate modification. Knowing this is critical to fully assessing the impact of climate change on specific populations vulnerable to the health effects of photochemical oxidant air pollution.