Patterns of environmental exposure-related documentation in emergency department visits within El Paso, Texas: a 25-year retrospective review

Abstract

El Paso, Texas, a city uniquely situated along the US-Mexico border, faces increased exposure to environmental pollutants due to factors including the mountainous desert landscape, industrial pollution, and high rates of transborder mobility along the El Paso-Juarez binational region. These unique environmental conditions and community characteristics make the region an important setting for environmental exposure surveillance. The association between traffic-related air pollution and adverse health outcomes is well established; however, the magnitude of impact that poor air quality and other environmental stressors place on border populations remains underexplored. Therefore, this study aimed to identify the most frequently documented environmental exposure-related ICD-9/10 codes among emergency department (ED) visits in El Paso and to characterize documentation patterns, temporal and seasonal trends, and selected healthcare utilization outcomes. The study retrospectively reviewed charts from ED visits at University Medical Center of El Paso (UMCEP) and El Paso Children's Hospital (EPCH) between January 2000 to December 2024, examining frequency, distribution, and longitudinal and seasonal trends of environmental exposure-related ED visits. Seven hundred and twenty-six charts met inclusion criteria for patients aged up to 89 years with at least one environmental exposure-related diagnostic code. The most frequently documented codes were Z77.098: Contact with and (suspected) exposure to other hazardous, chiefly nonmedicinal, chemicals, Z77.011: Contact with and (suspected) exposure to lead, and V15.89: Other specified personal history presenting hazards to health. Environmental exposure-coded ED visits increased notably between 2015 and 2016 and demonstrated seasonal variation, with higher counts in the summer months. These findings provide important insights to how environmental exposure-related ED visits are documented within the region, highlighting distinct temporal and seasonal patterns. However, the overwhelming use of non-specific exposure codes underscores a need for more granular documentation to better characterize environmental exposures and inform future surveillance strategies.