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SALT LAKE CITY — A new study has wide-ranging implications for water quality, mountain snowpack, air pollution and the struggling Great Salt Lake, finding that 90% of dust along the Wasatch Front and in Logan comes from dried up lake beds and desert basins.
The study by researchers at Brigham Young University, the University of Utah and Middlebury College in Vermont is the first of its kind to do a chemical analysis and comparison of playa dust and urban dust in the western United States. The results are startling.
“Yes, the findings were surprising,” said Gregory T. Carling, lead author of the study published in Chemical Geology. “We have seen these dust storms in the spring and the fall and it is pretty clear a lot of dust is coming from the playas and the desert. We didn’t know how much.”
Just 10% of the dust is generated by industries such as mining, gravel pits, petroleum refining or other urban activities, the study found.
Carling, an associate professor of geology at Brigham Young University, was joined by seven other researchers who collected playa dust at 15 sampling locations throughout western Utah, including near the Great Salt Lake, Dugway Proving Ground, the Sevier Dry Lake and Fish Springs in Juab County.
They also took dust samples in urban locations from the rooftops of four-story university buildings and then compared the chemical concentrations in the urban dust to what they found at the playa sites.
“We measured a whole bunch of elements, about 40 elements, and a majority of the concentrations in the playa dust are similar to the concentrations in the urban dust,” Carling said.
Researchers also examined dust deposition from mountain snowpack in the Wasatch and Uinta mountains over three subsequent springs, identifying multiple dust layers in the snow in the collection of 22 samples likely the result of single dust storm or other storms.
Dust collecting on snow accelerates its melting rate, which has implications for how long it stays in the mountains and also what metal concentrations it might contain, Carling said.
Research shows dust causes diseases such as asthma and pneumonia, contributes to harmful algal blooms in lakes, and decreases runoff.
This latest research was carried out against the backdrop of the dwindling waters of the Great Salt Lake, which is at historic low levels and is exposing more of its lakebed as a result, making more dust available to get into the atmosphere.
Saline lakes around the globe are drying due to diversions and drought, exposing lake beds which are major sources of mineral dust.
These things are interconnected in many ways we don’t normally think about. We are seeing water levels drop right before our eyes and there are things we can do to keep water in the lake.
–Gregory T. Carling, Brigham Young University
The dried up Owens Lake in California created the nation’s single largest source of PM10 dust pollution, spurring a $2 billion effort to mitigate its harmful health effects.
Aside from the immediate health effects, the elements in the dust can get into soil and cause problems for farmers if they are too alkaline, contaminate snow, and get into drinking water supplies.
“As the dust breaks down it is going to release some metals, and other metals it will hold onto,” Carling said. “Some of these metals are going to get into the water supply pretty readily, others will be stuck in the soil and not cause any harm,” Carling said.
He stressed the study emphasizes the need to keep water in these drying lakes, particularly the Great Salt Lake.
“These things are interconnected in many ways we don’t normally think about,” he said. “We are seeing water levels drop right before our eyes and there are things we can do to keep water in the lake.”