Assessing the Regional Impact of Biomass Burning on Air Quality in the Western United States (2010- 2023)
Jayde Alderman1, Christopher Rogers2, Ryan Fulgham3, John Walker4, Tim Sharac3, and Melissa Pulchalski3
1 WSP USA Environment & Infrastructure, Gainesville, FL, 2 WSP USA Environment & Infrastructure, Jacksonville, FL, 3 US Environmental Protection Agency, Office of Atmospheric Protection, Clean Air and Power Division, Washington, DC, 4 USDA Forest Service, Center for Forest Watershed Research, Otto, NC
This study investigates the influence of biomass burning across the Western US, utilizing satellite data from NOAA's Hazard Mapping System (HMS) to monitor smoke activities from 2010 to 2023. Regression analysis of smoke frequency at 18 CASTNET and 57 IMPROVE western sites, revealed that 94.4% of CASTNET sites and 86.0% of IMPROVE sites exhibit significant upward trends in smoke activity, with the most robust signals observed in the "Light" smoke density category. Several mid-western sites for both CASTNET and IMPROVE showed increasing significance throughout all smoke density categories. Elevated levels of particulate chemistry and gaseous pollutants associated with biomass burning further highlight the regional air quality implications. To identify key elements affected by smoke events, multiple methods were used to create a ranking system. The ranking system used parameters from Spearman's correlation, Welch's Two Sample T Test, and logistic regression. The final mean rank value along with bootstrap derived confidence intervals were used to identify analytes most likely to be affected by smoke events. Results consistently illustrated that Potassium, Calcium, Magnesium, and Ammonium at CASTNET sites, along with PM 2.5, Organic Carbon, PM 10, Total Carbon, and Potassium at IMPROVE sites, serve as reliable indicators of biomass burning episodes. Overall, these findings highlight the escalating regional impact of biomass burning over the past decade, underscoring the importance of fire management and air quality mitigation strategies.