Smoke designations for eastern Kansas monitoring sites during March-May 2022

Prescribed fires (fires intentionally set for mitigation purposes) produce pollutants, which have negative effects on human and animal health. One of the pollutants produced from fires is fine particulate matter (PM2.5). PM2.5 can penetrate deep into the lungs and harm cardiovascular and respiratory systems. The Flint Hills region of Kansas experiences extensive prescribed burning each spring (March - May). Smoke from prescribed fires is often understudied due to a lack of monitoring in the rural regions where prescribed burning occurs, as well as the short duration and small size of the fires. Our goal was to attribute PM2.5 concentrations to the prescribed burning in the Flint Hills. To determine PM2.5 increases from local burning, we used low-cost PM2.5 sensors (PurpleAir) and satellite observations. The Flint Hills were also affected by smoke transported from fires in other regions during 2022. We separated the transported smoke from smoke from fires in eastern Kansas. Based on data from the PurpleAir sensors, we found the 24-hour median PM2.5 increased by 5.2 µg m-3 on days impacted by smoke from fires in the eastern Kansas region compared to days unimpacted by smoke. We found the Flint Hills to be the most smoke PM2.5 impacted region compared to the surrounding area across satellite products and in-situ measurements. 

Methods
Daily PM2.5 measurements for ground-based monitoring sites in eastern Kansas were categorized by the type of smoke impacting the monitoring site using a decision tree. Designations were determined for every monitor during the eastern Kansas prescribed burning season (March - May) of 2022. The decision process considered the following variables: HMS smoke plumes and fire hotspots, in situ PM2.5 measurements from PurpleAir and EPA AQS sites, in situ coarse mode concentrations (PM10 - PM2.5) from EPA AQS sites, daily wind speed, categorization of the previous day, and proximity to an urban setting.