Contribution of Agricultural Fire and Wildfire Smoke to PM2.5 Concentrations in Rural Regions of the US and the Associated Health Impacts
September 09, 2025
Olivia Sablan
Committee: Jeffrey Pierce (Advisor); Emily Fischer (Co-advisor); Bonne Ford; Jeffrey Collett; Sheryl Magzamen (Environmental and Radiological Health Sciences)
Abstract
Exposure to landscape fire smoke is a growing public health concern. Fine particulate matter (PM2.5) from fires has been associated with a suite of adverse cardiorespiratory health outcomes, yet many rural and underserved regions lack adequate monitoring to quantify smoke PM2.5 to then determine health impacts. We quantified smoke PM2.5 from wildfires in New Mexico and agricultural fires in southern Florida. We also conducted an epidemiological analysis with health data in New Mexico to investigate associations with Emergency Department (ED) visits and wildfire smoke exposure, as well as the sensitivity of the analysis to study inputs.In Florida, we use public low-cost PurpleAir sensors, regulatory monitors, and 29 PurpleAir sensors deployed for this study to quantify PM2.5 from agricultural fires. We found satellite imagery is of limited use for detecting smoke in this region due to the cloud cover, overnight smoke, and the agricultural fires being small and short-lived. For these reasons, surface measurements are critical for capturing increases in PM2.5 from smoke, and we used multiple smoke designation methods. We contrast the region near the Everglades Agricultural Area (EAA) with large populations of low-income and minoritized groups to the more affluent coastal region. The inland region experienced more smoke-impacted monitor days than the Florida east coast region, and there was a higher study-average smoke PM2.5 concentration in the inland area. These findings highlight the need to increase air quality monitoring near the EAA.
In New Mexico, we first used ED visits in an epidemiological analysis to better understand the uses of four different smoke exposure estimates of NM during the state’s largest wildfire (Calf Canyon/Hermit’s Peak) in summer 2022. We tested several smoke PM2.5 estimates in this analysis and found results vary between estimates. The smoke exposure estimate that leveraged both regulatory and PurpleAir measurements provided more precise exposure estimates, compared to the estimates with only regulatory monitors and the estimates from a chemical transport model. Finally, we compared the use of ED visits to Syndromic Surveillance (SS) reports from 2019-2022 in New Mexico. SS is a real-time, voluntary reporting system of ED visits. We found that both health datasets yield similar results; however, all-cardiovascular related visits/reports had odds ratios of more similar values than the all-respiratory and asthma. Overall, the SS reporting system can be a valuable tool for allocating resources in New Mexico during an intense, local wildfire event.