A Review of Community Smoke Exposure from Wildfire Compared to Prescribed Fire in the United States

Prescribed fire, intentionally ignited low-intensity fires, and managed wildfires—wildfires that are allowed to burn for land management benefit—could be used as a land management tool to create forests that are resilient to wildland fire. This could lead to fewer large catastrophic wildfires in the future. However, we must consider the public health impacts of the smoke that is emitted from wildland and prescribed fire. The objective of this synthesis is to examine the differences in ambient community-level exposures to particulate matter (PM_2.5) from smoke in the United States in relation to two smoke exposure scenarios—wildfire fire and prescribed fire. A systematic search was conducted to identify scientific papers to be included in this review. The Web of Science Core Collection and PubMed, for scientific papers, and Google Scholar were used to identify any grey literature or reports to be included in this review. Sixteen studies that examined particulate matter exposure from smoke were identified for this synthesis—nine wildland fire studies and seven prescribed fire studies. PM_2.5 concentrations from wildfire smoke were found to be significantly lower than reported PM_2.5 concentrations from prescribed fire smoke. Wildfire studies focused on assessing air quality impacts to communities that were nearby fires and urban centers that were far from wildfires. However, the prescribed fire studies used air monitoring methods that focused on characterizing exposures and emissions directly from, and next to, the burns. This review highlights a need for a better understanding of wildfire smoke impact over the landscape. It is essential for properly assessing population exposure to smoke from different fire types.