THE IMPACTS OF WILDFIRE SMOKE AEROSOLS ON SURFACE AIR QUALITY IN CALIFORNIA: A MULTI-YEAR STUDY USING GEOSPATIAL TECHNOLOGIES

Recent advances in geospatial technologies and earth data opened up a wide array of aerosol science and allow detailed assessment of wildfire smoke impact on air quality. Globally, wildfire driven air pollution often cited as one of the significant reasons for adverse impact on public health. In recent times, ambient concentrations of particulate matter with diameters less than 2.5 μm (PM_2.5) in the US experiences a remarkable degradation due to wildfire smoke, which jeopardize the country’s efforts for last few decades to improve air quality. Since 2016, the effects are more alarming in western states like California, Oregon, and Washington, where smoke has added enough pollution to the air to wipe out nearly half of the total air quality gains made from 2000 onward. This study aims to predict the impact of wildfire smoke aerosols on surface air quality and associated health hazards in California using both ground-based PM_2.5 measurements from the United States Environmental Protection Agency (USEPA) and satellite data products such as Landsat and MODIS. In addition, USEPA Positive Matrix Factorization (PMF) model will be employed to assess the source contribution of wildfire smoke to the ambient level of PM_2.5, which provides robust uncertainty estimates and diagnostics of environmental data. Furthermore, hybrid single-particle Lagrangian integrated trajectory (HYSPLIT) model will also be used to further support PMF model for the source apportionment of PM_2.5. The impact of air pollution on health is complex (nonlinear) and there may be cross effects between different pollutants. Considering this, health impacts will be assessed using Hazard Quotient (ratio of the potential exposure to a substance and the level at which no adverse effects are expected) for PM_2.5. Hazard Quotient will be calculated using the available PM_2.5 data from ground-based monitoring stations, and the country specific National Ambient Air Quality Standards developed by USEPA. Outcome of this project will help us predicting the contribution of wildfire smoke aerosol, particularly PM_2.5 in local airsheds through the source apportionment of ambient air pollutants. It is also expected to help us advancing our understanding of further application of geospatial data for environmental risk modeling.