Pollutant emission factors for smoldering conifer forest duff

Abstract

Prescribed fires can be a significant source of air pollution with negative consequences for public health and safety. Therefore, smoke management is a key element in the planning and execution of prescribed fires. Emission factors (EF), which quantify the relative abundance of pollutants released by wildland fires, are a needed input for the emission calculations which are essential to effective smoke management. A key challenge when conducting prescribed fires near sensitive receptors such as roadways, communities, and outdoor recreational sites, is limiting smoke production from long-term smoldering of coarse dead wood and duff. We carried out a laboratory study to address a knowledge gap in duff EF. We report EF of carbon dioxide (CO2), carbon monoxide (CO), methane (CH4), the sum of 19 nonmethane hydrocarbons (NMHC) and fine particulate matter (PM2.5) for smoldering duff during laboratory burns of duff harvested from Douglas-fir forest stands in eastern Oregon. This study suggests the default EFPM2.5 used in the First Order Fire Effects Model, a widely used tool for planning prescribed fires and estimating emissions, may significantly underestimate PM2.5 emissions for smoldering duff in Western conifer forests.

Citation

Urbanski, Shawn P.; Kay, Shannon; Baker, Stephen P.; Lincoln, Emily N.; Ross, Andrew A.; Blunck, David. 2024. Pollutant emission factors for smoldering conifer forest duff. Gen. Tech. Rep. RMRS-GTR-444. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 45 p. https://doi.org/10.2737/RMRS-GTR-444.