Note to readers •This story is made possible through a partnership between The Salt Lake Tribune and Grist, a nonprofit environmental media organization.

The growing dust problem posed by the drying Great Salt Lake isn’t just a threat to air quality. New research shows that the toxic metals blowing from its exposed lakebed may be working their way into our food, too.

Scientists at Utah State University published a study this month in which they collected dust from Farmington Bay and applied it to cabbage plants grown in a greenhouse. After two applications, plant tissue absorbed metals and metalloids from the dust, including arsenic, sodium and uranium. Other contaminants, like lead, can collect on the leaves. Those pollutants occur naturally in the Great Salt Lake but also stem from past industrial activity.

“There’s the phrase ‘after the dust settles,’” said Molly Blakowski, lead scientist for the study, “and we usually think that means the problem is over. But with Great Salt Lake dust, that’s actually where a different set of processes can begin.”

Besides being absorbed through leaves, pollutants likely work their way through soils and into roots, accumulating in the food chain, Blakowski said.

She started her research on the Great Salt Lake in 2019 as a doctoral student in the university’s Department of Watershed Sciences.

“Our work reinforces that declining lake levels are not just a water issue and not just an air quality issue,” Blakowski said. “Dust affects a lot of different parts of our lives.”

Blakowski and her mentor, associate professor and geological scientist Janice Brahney, selected Farmington Bay to collect dust samples because it tends to generate a lot of particulate matter, and it lies close to population centers in Salt Lake City and Davis County. The bay is fresher than other parts of the Great Salt Lake, so it doesn’t form a protective salt crust. Wastewater treatment plants discharge into the bay and its tributary, the Jordan River. It is shallow and prone to toxic algal blooms, as well.

“It’s the biggest dust-producing area,” Brahney said. “It’s also potentially the grossest dust-producing area.”

They collected 15 samples of dust naturally kicked up by the wind. They then took them to the university’s greenhouse and applied dust using silicone brushes twice to simulate two dust storms.

“We wanted to have a controlled environment,” Brahney said, “because adjacent to the lake, you actually have multiple sources of heavy metals in the atmosphere.”

Those other pollution sources include quarries, oil refineries and freeway traffic. The researchers wanted to understand impacts from the lake itself.

The scientists found some metals lingered within cabbage exposed to Great Salt Lake dust, even after they were thoroughly washed.

But Blakowski said that isn’t a reason for Wasatch Front residents to abandon their backyard gardens.

“We have no reason to believe that Great Salt Lake dust is causing plants and food crops grown in Utah to exceed food safety limits,” she said.

The bigger concern is how long-term exposure to blowing lake dust may alter soils and plant physiology downwind. Previous research in South America explored whether the desiccated Mar Chiquita caused sodification of agricultural lands, a process in which sodium builds up in soils and weakens crops.

“It’s so important to be able to grow our own food,” Blakowski said. “And agriculture is a huge part of the Utah way of life.”

The findings were published in the journal Atmospheric Environment.

The scientists hoped to evaluate whether the dust was infiltrating soils and being taken up by the cabbage roots as well, but the sandy soils they used made collecting samples difficult.

Brahney said she’d like to study root uptake further, along with other non-metal contaminants blowing from the lake, like organic compounds and cyanotoxins from bacteria. She’d also like to evaluate dust impacts on other types of crops, like root vegetables and fruiting plants.

Anna Paltseva, a professor of agronomy at Purdue University, said root vegetables, leafy greens and herbs are most vulnerable to absorbing airborne pollutants and contaminants that accumulate in soil. She did not participate in the Utah State University study, but reviewed the findings.

“It was in a greenhouse,” Paltseva said, “so what is happening in the real world is a real question.”

She called the findings a “good first step,” however, and said a follow-up study could collect produce from community gardens and interview residents around the lake about how much backyard produce they typically consume. But she reiterated that Utahns shouldn’t panic over the study’s findings.

“Even if you eat contaminated cabbage from time to time or a carrot, it’s not going to kill a person,” she said. “It’s about length of exposure.”

Justin Richardson, a professor of geosciences at the University of Virginia, studies how metals travel through ecosystems and move through the food web. He said he was surprised by the amount of lead found in Brahney’s dust samples. She reported concentrations at 55.9 parts per million. That’s more than 50 times higher than levels considered safe for leafy greens by the United Nations, he said. Children are particularly vulnerable to lead, which can impair brain development.

“Fortunately dust is an exterior type of pollutant,” Richardson said, and lead wasn’t absorbed by the cabbage leaves in the Utah State study.

Still, Paltseva said it highlights one of the single most important things Utahns can do if they’re worried about the impacts of Great Salt Lake dust on their kitchen gardens.

“Always wash and peel produce [you] grow,” Paltseva said. “But ... don’t be afraid.”