A0232
Title: Evaluating heterogeneous air quality impacts of prescribed fire and wildfire in the United States using causal forest
Authors: Xiao Wu - Columbia University (United States) [presenting]
Abstract: Increasing wildfire activities in the United States have generated far-reaching effects on ambient air pollution and human health. Although prescribed fires are implemented as a preventive measure against uncontrolled wildfires, the health risks associated with the smoke from these controlled burns remain contentious. Previous studies indicated that pollutant emissions from prescribed fires are generally lower than those from wildfires; however, it is unclear whether this reduction translates to lessened population exposure to air pollutants from smoke. In addition, the factors that led to differences in air quality impacts of prescribed fires and wildfires were underexplored. Using fire data from California, Florida, and Georgia (2006-2020) and a causal forest approach, the air quality impacts of prescribed fires and wildfires are quantified, respectively, their differences in affecting population-level smoke exposure are examined, and important factors that explain such differences are identified. On a per square-kilometer basis, prescribed fires resulted in over six times less smoke exposure than wildfires. Using a rank-weighted average treatment effect (RATE) estimating approach, prescribed fires are also found to generate reduced smoke exposure in areas with higher relative humidity and higher precipitation. As such, the judicious use of prescribed fires can be guided, and public health outcomes while mitigating wildfire threats can be optimized.
