Spatial Analysis of Particulate Matter Air Pollution, Sediment Geochemistry and Asthma Outcomes Associated with the Shrinking of the Great Salt Lake

Particulate matter pollution in northern Utah comes from various sources, including industry, traffic and the western desert, plus dried shoreline sediments of the Great Salt Lake (GSL). Particulate matter air pollution, particularly that containing heavy metals, can have severe effects on human health. Since the high-water levels in the 1980s, the GSL has been drying and reached record low water levels in 2022. Accurate Environmental Protection Agency (EPA) PM2.5 and PM10 sensors within northern Utah are few. This makes the mapping of particulate matter air pollution difficult. We show spatial patterns in particulate matter air pollution using a combination of PM2.5 and PM10 levels from 7 years of Purple Air Network data (a network of inexpensive air quality sensors installed by private citizens or businesses) and atmospheric optical depth (AOD) data from Sentinel imagery. We also show that PM2.5 and PM10 levels are significantly higher on a regular basis within 10 km of the Great Salt Lake and close to Farmington and Bear River Bays, which are upwind of large population centers. The levels of heavy metals (arsenic, copper, lead and zinc) were particularly high for the Farmington Bay and Saltair study sites, and the percentage of silt-sized particles that are most susceptible to wind erosion was largest for Farmington Bay, which is upwind of large population centers. Links between heavy metal concentrations, particle size and PM air pollution and asthma outcomes are investigated. Closeness to the lake was a significant predictor of asthma emergency room visits in 2018–2022 but not in 2016.