Study shows smaller storms may fly under the radar, but still carry heavy risks.
Health risks associated with dust pollution continue to kick up interest in the Great Salt Lake, and new research shows Utah’s youngest residents may be the most vulnerable to its fallout.
Scientists have long known toxic heavy metals from natural sources and human activity, like mining, exist in the Great Salt Lake’s exposed lakebed, which bakes and erodes as the water recedes. Ensuing storms can send its dust billowing into cities all along the Wasatch Front.
While prior research mostly focused on what the dust is doing to our lungs, it can cause a lot of harm when it ends up in our stomachs, too, a study published last month in the journal GeoHealth found.
“So much of this dust ingestion is incidental,“ said Annie Putman, a hydrologist with the U.S. Geological Survey and lead author of the study. ”It’s eating some produce from the garden with a dirty hand, or eating it without washing it."
Children younger than six years old are most at risk, the research found, because they tend to consume higher doses of dust and dirt relative to the size of their small bodies.
“I have a child who’s nine months old, so I’m thinking about this all the time,” Putman said. “Babies ... are constantly picking things up and exploring them with their mouths.”
Her research found other issues for residents of all ages, including the unhealthy metals mixed in northern Utah dust. They can vary from community to community. And not all of them come from the Great Salt Lake’s playa — current and past industrial activities like mining, smelting and fossil fuel refining also contribute to dust pollution.
Putman created dust filters using round cake pans with glass marbles suspended over plastic mesh. She placed them at 17 sites in Davis, Weber, Box Elder and Cache counties.
“This is kind of an old but very inexpensive methodology for pretty successfully capturing dust,” Putman said. “It’s great because you don’t need electricity. You don’t need anything special. You just set the traps out, you wait, you come back.”
She collected her samples in the late summer and fall of 2022, a particularly dry year that saw the Great Salt Lake sink to a record low elevation. She then sent the samples to the University of Utah to analyze the dust’s isotopes.
“By knowing the chemical composition,” said Diego Fernandez, a research professor in geology and geophysics at the U. and co-author of the paper, ”we can separate the two main sources [of metals], the ones from the lake and the ones from human activities."
Bountiful, they found, had more dust pollution from human disturbance, like nearby gravel quarries. Communities to the north, however, have higher exposure to playa emissions.
Contaminants of concern identified in the study include arsenic, which can cause cancer and diabetes. It naturally occurs across the Great Salt Lake playa. Over millennia, streams and rivers scrubbed the material from mountains and rocks, depositing it in the terminal lake’s sediment.
The scientists also found lead, which mostly comes from human activities like mining. It was once added to gasoline as well, and became part of the region’s dust both from vehicle emissions and refineries near Farmington Bay. Lead can permanently alter brain and nervous system development, especially in children.
The metal has collected in the playa sediment since the 19th century, along with other pollutants from the state’s legacy of industrial activity.
“Because we’re in a closed basin,” Putman said, “much of what we do ... has a chance to end up in the lake.”
Some of the dust from her samples notably contained hazardous levels of thallium as well, a highly toxic element that can cause hair loss, gastrointestinal issues and premature birth when inhaled or ingested.
Putman’s previous research found the material could be linked to Kennecott’s copper mine and smelter in Salt Lake County.
But in her research published last month, she also found high levels of the thallium near Ogden, many miles away and on a different section of the lake than Kennecott’s facilities.
In a 2023 report she provided for the Utah Division of Forestry, Fire and State Lands — which helped fund the study — Putman posited the thallium may have come from the Ogden Defense Depot Superfund site, or from nearby hot springs.
“It’s a thread we haven’t been able to pull yet,” Putman said. “There’s potentially something interesting there.”
Many of Putman’s findings, however, confirmed scientists’ suspicions.
“I’ve always thought that it’s the area northeast of Farmington Bay that’s most likely to be the hardest hit” by Great Salt Lake dust, said Kevin Perry, a professor of atmospheric studies at the U. who reviewed the study but was not involved in it.
The area around the water-starved bay does not have any state-run air quality monitors, Perry said. But Putman’s study found the communities to the north and east of it saw the highest “flux” of lakebed dust, or rate of particulate transport.
“It confirms what the models have shown and what my intuition basically says,” Perry said. “We definitely need to put monitors in that area.”
Putman also noted that during the period she collected samples, there were no meteorological events kicking up major dust storms. Still, her cake pans trapped plenty of dust, indicating smaller, shorter dust events may be flying under scientists’ radar.
“We have no idea how frequent they are,” Perry said. “[But] they have big impacts on relatively small community areas.”
The Utah Department of Environmental Quality is currently building a more extensive monitoring network to track dust events across the state, which the scientists praised.
Beyond taking precautions like staying indoors during dust storms, Putman’s study recommends washing hands, toys and produce, along with removing shoes indoors and using vacuums with HEPA filters, to reduce risks.
“It is important to do science that’s relevant to people,” Putman said, “so that’s a major motivator for all of us who worked on this.”
Her study also recommends an obvious, but likely costly solution for protecting public health — preventing dust from blowing off the lakebed in the first place.
