Air Quality and Asthma Hospitalization Rates: Evidence of PM2.5 Concentrations in Pennsylvania Counties

According to the World Health Organization, 235 million people around the world currently suer from asthma, including approximately 25 million in the United States. There is substantial epidemiological evidence particulate matter concentrations and asthma. Based upon county level data from 2001-2014, a spatial panel framework with weights based upon prevailing wind patterns is used to investigate the direct and indirect impacts of PM2:5 concentration levels on asthma hospitalization rates in Pennsylvania. This model controls for population density, precipitation, per capita income, and smoking rate. Results show that PM2:5 concentrations have positive eects on asthma hospitalization rates (both direct and indirect). For example, a one =m3 increase in PM2:5 concentrations throughout all counties in Pennsylvania raises the number of annual asthma hospitalizations by over 400, with 53.8% of this increase occurring due to spillover eects. This study highlights the need for a more accurate impact analysis of ambient air pollution on asthma that re reflects the impacts of both local and neighboring regions' air quality. In the case of asthma hospitalization rates from PM2:5 pollutions, an appropriate wind direction algorithm also is important to identify spillover effects across counties.

据世界卫生组织（World Health Organization）统计，目前全球约有2.35亿哮喘患者，其中美国约有2500万。已有大量流行病学证据表明颗粒物浓度与哮喘存在关联。本研究基于2001年至2014年的县级层面数据，采用以主流风向为权重构建的空间面板模型，探究宾夕法尼亚州内PM2.5（细颗粒物）浓度水平对哮喘住院率的直接与间接影响。该模型纳入人口密度、降水量、人均收入及吸烟率作为控制变量。研究结果显示，PM2.5浓度对哮喘住院率存在正向影响（涵盖直接影响与间接影响）。例如，若宾夕法尼亚州所有县域的PM2.5浓度每提升1微克/立方米，该州年度哮喘住院人数将增加400余人，其中53.8%的增长源于溢出效应（spillover effects）。本研究强调，需开展更为精准的环境空气污染对哮喘影响的分析，以同时反映本地与邻近区域的空气质量所带来的效应。针对PM2.5污染引发的哮喘住院率而言，采用适配的风向算法对于识别县域间的溢出效应同样至关重要。