The Effect of Aerosol Dispersion on Asthma Related Hospitalizations

Central North Carolina ranks among the top 10% for emissions of carbon monoxide (CO), oxides of nitrogen (NOx), volatile organic compounds (VOCs), particulate matter <10 mm (PM10), and number of days (8 h) in exceedance of National Ambient Air Quality Standards (NAAQS). According to recent studies, particulate matter <2.5 mm (PM2.5) is easily carried into the lungs resulting in inflammation; thus initiating or worsening asthma and asthma-related conditions.

The objective of this study is to identify possible causes for regional biases among reported cases of asthma. Demographic variables, land usage, climatological trends, and atmospheric dynamics within the convective boundary layer (CBL) are geographically compared to hospital discharge data on a seasonal basis. Outputs from the Penn State/NCAR Mesoscale Model (MM5) and the CALPUFF dispersion model are mapped over zip code-referenced asthma cases using geographic information systems (GIS). Major transportation routes passing through the domain contribute to elevated concentrations of PM2.5.

Results suggest that there are significant links between regional 10-m wind patterns and asthma-related hospitalizations. Notable increases in reported cases coincide with downstream flow from regions of elevated aerosol concentration. Previous studies show a dependency on socioeconomic status; however, these parameters strongly influence places of residence. Results from this study showing dependence on lower-tropospheric dynamics also imply the possibility that previous findings related to socioeconomic status are circumstantial.