Effects of Ambient Air Pollution on Asthma-~Related Emergency Department Visits within the Las Vegas Metropolitan Area

Loiren E. Monardes


The objective of this research was to evaluate the risk for asthma-related Emergency Department visits and their association with ambient air pollution within the Las Vegas metropolitan area. All data were aggregated by date and ZIP Code. The association was analyzed by applying the distributed lag non-linear model in an attempt to identify elevated concentrations of specific air pollutants

as triggers and their delayed effects (lag days). Relative Risk (RR) and 95% confidence intervals were produced, while adjusting for socioeconomic status. This ecological population-based study analyzed daily asthma counts of Emergency Department visits from January 1st, 2009 to December 31st, 2014 (N= 109,550). The exposure-outcome analysis found that when PM10 reaches 265

μg/m3, RR is greater than 1, between 0-2 days lag, dissipates, and peaks between 5-7 days lag. At initial exposure, PM10 had a RR of 2.83 (95% CI = 1.11, 7.20). At 7 days lag, PM10 reached a RR of 2.91 (95% CI= 1.21, 7.02), supporting that these associations present a non-linear lag effect. Understanding the adverse effects caused by elevated concentrations of criteria air pollutants, particularly when they exceed federal standards, and recognizing that a lag time exists, is a call to action for healthcare providers to educate their patients as to proper exposure prevention strategies and the development of tailored asthma management plans.