Increased Levels of Atmospheric Phosphorus and Other Nutrients Associated with Fires in the Western United States
NICOLE OLSON, Katie Boaggio, R Byron Rice, Stephen LeDuc, Uma Shankar,
U.S. EPA Abstract Number: 405
Working Group: Biomass Combustion: Outdoor/Indoor Transport and Indoor Air Quality
AbstractWildfire activity is increasing and linked to climate change effects including rising global temperatures and more frequent drought conditions. Wildfire emissions likely impact human health and sensitive ecosystems, particularly in the western United States where fire frequency and severity have increased dramatically in the past decade. Herein, 15 years (2006-2020) of PM2.5 chemical speciation data were linked with smoke plume analysis to identify airborne nutrients that were elevated on smoke-impacted days. Except for ammonium, all macro- and micro-nutrients analyzed (phosphorus, calcium, potassium, sodium, silicon, copper, aluminum, iron, manganese, magnesium, zinc, nitrate) were elevated on fire days, with some nutrients episodically elevated >10,000% during select fire events. A box model was developed to calculate phosphorus deposition from atmospheric concentrations on smoke days, facilitating a comparison to other fluxes of phosphorus. Air mass trajectory analysis and satellite cyanobacteria measurements suggest fire emissions influence algal activity in lakes up to 65 kilometers downwind from fires. These results suggest potential implications for the emergence of harmful algal blooms, even in alpine lakes with limited upstream agriculture and nutrient inputs.
The views expressed in this presentation are those of the author(s) and do not necessarily represent the views or policies of the Environmental Protection Agency.