Effects of Heat Waves and Fine Particulate Matter (PM_2.5) Air Pollution on Emergency Medical Services Call Volume in San Antonio, Texas.

Background: San Antonio, Texas, has long, hot summers and an increasing problem with air pollution. This study examined the relationship between heat waves at three heat index thresholds, along with air particulate pollution from fine particulates (PM2.5), and emergency medical services (EMS) call volume during the five hottest months of the year in San Antonio. Methods: A total of 648 days, from 2015 to 2018, were included in the analysis. Daily EMS call volumes were obtained from the city of San Antonio. Heat waves and heat index calculations were based on daily temperature and humidity data obtained from the United States National Oceanic and Atmospheric Administration National Centers for Environmental Information. PM2.5 data were collected at multiple sites across San Antonio by the United States Environmental Protection Agency (EPA). Two negative binomial regression models with time-stratified case-crossover were performed for each of the three heat wave heat index thresholds, 90 degrees Fahrenheit (°F), 95°F, and 100°F. Results: The analysis of heat alone and heat along with PM2.5 showed significant and positive associations between the heat index at the 90°F and 95°F thresholds and the number of EMS calls, holding the seasonal effects constant. Although, at 100°F, the effect of the heat wave on EMS call volume was not statistically significant, PM2.5 was significantly and positively associated with an increase in EMS call volume. Conclusions: Scientific findings suggest a correlation between the dyads of increased frequency of heat waves and poor air quality with disease condition and compromised well-being in many towns and cities in the United States and beyond. Consequently, this study examines and attempts to demonstrate the impact of health waves in combination with air pollution on public health using the city of San Antonio as a pilot. [ABSTRACT FROM AUTHOR]