Chemical comparison of dust and soil from the Sevier Dry Lake, UT, USA

Composition of dust transported locally, regionally, and globally has influences on human health, ecosystem functioning, and biogeochemical cycling. This study aimed to characterize differences between dust and soil samples at a dust source in the eastern Great Basin of Utah, USA. Dust and soil samples were collected from the Sevier Dry Lake, a known dust producing playa in this region. Samples were resuspended in the laboratory and collected using an 8-stage Davis Rotating-drum Universal-size-cut Monitoring (DRUM) impactor. Collected samples were analyzed for elemental concentration using Synchrotron X-Ray Fluorescence (SXRF). Element concentration was normalized and analyzed for enrichment relative to major soil element Al. Dust and soil samples contain similar enrichments of major soil elements including Si, Fe, Ca, K, Mg, and Ti. However, dust samples were significantly more enriched in Na derived from the surface salts of the Sevier Dry Lake. Minor soil elements (all elements analyzed apart from the major soil elements) were generally more enriched in dust samples and had larger enrichment values (up to 104) than seen in previous studies. Further, for dust and soil samples, the fine fraction (<2.5 μm) was more enriched in minor soil elements than the coarse fraction (2.5-10 μm). Dust from this source, containing elevated levels of potentially hazardous elements, degrades air quality in the Salt Lake City metropolitan area of Utah and is deposited in the alpine ecosystems of the Wasatch Mountains.