Industrial Particulate Pollution and Historical Land Use Contribute Metals of Concern to Dust Deposited in Neighborhoods Along the Wasatch Front, UT, USA.

The Salt Lake Valley, UT, USA, is proximal to the desiccating Great Salt Lake (GSL). Prior work has found that this lakebed/playa contributes metals‐laden dust to snow in the Wasatch and Uinta Mountains. Dust and industrial particulate pollution are also delivered to communities along the Wasatch Front, but their sources, compositions, and fluxes are poorly characterized. In this study, we analyzed the dust deposited in 18 passive samplers positioned near the GSL, in cities in and near the Salt Lake Valley for total dust flux, the <63 µm dust fraction, 87Sr/86Sr, and trace element geochemistry. We compared spatial patterns in metal flux and abundance with community‐level socioeconomic metrics. We observed the highest dust fluxes at sites near the GSL playa. Within the urban corridor, 87Sr/86Sr and trace element relative abundances suggest that most of the dust to which people are regularly exposed may be fugitive dust from local soil materials. The trace metal content of dust deposited along the Wasatch Front exceeded Environmental Protection Agency screening levels and exhibited enrichment relative to both the upper continental crust and the dust collected adjacent to GSL. Sources of metals to dust deposited along the Wasatch Front may include industrial activities like mining, oil refining, as well as past historical pesticide and herbicide applications. Arsenic and vanadium indicated a statistically significant positive correlation with income, whereas lead, thallium, and nickel exhibited higher concentrations in the least wealthy and least white neighborhoods. Plain Language Summary: The Salt Lake Valley, UT, USA is near the drying Great Salt Lake. The shrinking lake reveals a playa, composed of fine grained, metal‐contaminated material. Dust storms lofting these sediments may pose a threat to air quality in the nearby cities of Ogden, Bountiful, Salt Lake, and Lehi. We investigated strontium isotopes as well as a suite of trace elements in dust sampled near the playa and within the urban corridor. We found the most, and coarsest dust was deposited outside of the city. The dust from the playa and the dust collected in the city were not similar in terms of trace elements or strontium isotopes, suggesting that much of the dust collected in the city may come from local fugitive dust sources. The dust within the city had many different metals that are known to be associated with anthropogenic and industrial activities, like mining, oil refining, and agriculture. Abundances of some metals, like As and V were higher in wealthier neighborhoods, while abundances of Pb, Tl, and Ni were higher in lower income and more ethnically diverse neighborhoods. Key Points: Dust near the Great Salt Lake playa differs from dust collected in nearby citiesMetals in city dust can be traced to specific nearby industriesFugitive dust may be an important dust source for human exposure within cities [ABSTRACT FROM AUTHOR]