A retrospective analysis of the association of dust storms and respiratory hospitalizations in El Paso, Texas, using a case-crossover study design

Dust storms, blowing dust and related phenomena frequently occur in El Paso, Texas, but little is known to date about their respiratory health effects. The association between dust events and hospitalization for respiratory illnesses (asthma, bronchitis, sinusitis and upper respiratory infections) was evaluated through a case-crossover study design. The goal was to ascertain the respiratory health effect of dust events on El Paso residents, adjusted for weather and other pollutants, and to explore potential harmfulness on different subgroups of residents. A case-crossover study allows patients to serve as their own controls, in order to reduce confounding.

Dust / weather and hospitalization data were obtained from daily records covering the six-year period (2000- 2005). Hospitalization data for El Paso County were compiled by the Texas Health Care Information Council in Austin, Texas. Dust occurrence records for El Paso International Airport (ELP) were derived from a database maintained by the National Weather Service Forecast Office in Santa Teresa, New Mexico. Days with only convective dust events (haboobs) were combined with dust-free days for the analysis. Data for other weather variables and air pollutants were obtained from the National Weather Service and the Texas Commission on Environmental Quality. Hourly weather and air pollutant data were pre-processed to finalize a group of daily weather-pollution variables for the case-crossover analysis.

For the population of El Paso County as a whole, residents were 10.3% more likely to be hospitalized for a respiratory illness on a day with a synoptic-scale dust event than on a day without a dust storm or with only convective dust. Adjusting for other weather and air pollution covariates gave a similar finding. No significantly different effects were noted for different age groups of patients (children, adults, and the elderly), different genders for any age group, or for patients with different insurance status (private, Medicare, Medicaid, uninsured, and other). Only for the subgroup of adults, there was a significant increase in respiratory hospitalizations three days after a dust event occurred.

This case-crossover study of a large dataset reveals a significant effect of dust storms on hospitalization of El Paso, Texas residents for respiratory diseases, whether adjusted for weather- pollution covariates or not. This research contributes to filling the gap in scientific research about dust's effect on respiratory health in the United States.