The research "doesn't say the sky is falling and we're all going to die," said one scientist, but she added the dust is "a concern and it's definitely worth continuing to look at."

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Two recent studies found "scary" concentrations of arsenic and other potentially harmful chemicals in the dust on dry portions of the Great Salt Lake and in sediment in its tributaries, said Diego Fernandez, a research professor.

The Great Salt Lake is a terminal lake, meaning it receives runoff from a vast drainage basin spanning northern Utah and parts of three other states. Once water gets to the lake, though, the only way it leaves is evaporation.

Metals from natural sources and human actions like mining build up in the lake bed from its tributaries and precipitation. As the lake has shrunk, more of its dry playa has been revealed, and Utahns have observed strong winds lifting dust off the exposed lakebed. This dust -- and the metal compounds within -- affects the air that millions breathe on the Wasatch Front.

One new study found that the dust may be more harmful than other major dust sources impacting northern Utah because sediments from the Great Salt Lake, if inhaled, are more likely to interact with our bodies in a harmful way.

More research looked at sediments in the Weber River -- which flows into the lake's south arm near Fremont Island -- and further confirmed those findings.

The research "doesn't say the sky is falling and we're all going to die," said Kerry Kelly, a chemical engineering professor at the University of Utah who worked on the first study.

"This does say it's a concern and it's definitely worth continuing to look at," Kelly added.

Utah's Division of Air Quality points out the studies note there are differences between the research results and what a person experiences. The state agency said that its own analysis of dust samples showed no increase in the severity of dust events involving PM10 -- particulate matter with a diameter of 10 micrometers or less, about five times smaller than human hair.

These studies show that there is potential for Great Salt Lake dust to harm Utahns. But Kelly and other scientists said there hasn't yet been enough research directly linking dust events and health impacts, measuring how much of the contaminants people are breathing in or showing exactly where dust from the playa goes within the Salt Lake Valley.

"We really need to think about how to best create a sampling network that can capture all of these dust events," said Kevin Perry, an expert at the U. who has been dubbed "Dr. Dust," "so that we can know how frequent they are and how severe they actually are."

Inhaled Great Salt Lake dust is more harmful than other dust

Northern Utah is impacted by several dust sources -- like dry Sevier Lake, Tule Lake and the West Desert -- but the Great Salt Lake is a significant emerging dust source, Perry explained.

He completed a soil survey of 800 square miles of exposed lakebed in 2018. During that research, Perry found several elements within Great Salt Lake dust that were concerning from a health perspective, like arsenic.

The presence of a chemical doesn't necessarily present risk, said Fernandez, a University of Utah research professor in geology and geophysics who contributed to both studies.

"You can plant lettuce and tomatoes in soil that has a lot of lead, and most of the time that lead doesn't get into the plants," he said.

(Francisco Kjolseth | The Salt Lake Tribune) Strong winds blow dust across the shores of the Great Salt Lake obscuring the peaks of Antelope Island on Wednesday, March 29, 2023.

But Perry's most recent study, published online in the journal Atmospheric Environment, found that when sediments from the Great Salt Lake get into the air, like during a dust storm, they become more bioavailable than sediments from other sources that expose northern Utahns to dust.

Sediments that are more bioavailable are more likely to cause potential harm to your body if you breathe them in.

Now, with the understanding that sediments within Great Salt Lake dust are bioavailable, Perry is primarily worried about long-term exposure.

"What we're really concerned about here is an increase in the rate of cancer in people who would be exposed to this over a long period," he said.

But there are more questions that Perry said need to be answered before he can confirm that inhaling Great Salt Lake dust causes adverse health effects. Scientists don't yet know how much exposure to many elements in dust from the uncovered lakebed puts human health at risk, he explained.

Some of those elements, Perry said, may not be toxic. "But we need to know the concentrations that people are actually breathing to know that," he said. "Unfortunately, we don't have that information."

The majority of Great Salt Lake dust is made up of a particle called PM10. But despite the Utah Legislature giving the Utah Division of Air Quality over $275,000 in 2022 for five new PM10 monitors, the state hadn't installed any as of July.

Because of this lack in PM10 monitoring, Perry said, researchers don't know how much dust people are exposed to and how frequently they're exposed to it.

(Spenser Heaps | Pool) Dust blows off dry lakebed of the Great Salt Lake as seen from Farmington Bay on Friday, Aug. 19, 2022.

A spokesperson for the Division of Air Quality explained that while "Utah does not have monitors that would most frequently capture dust from the Great Salt Lake," that is "primarily a result of placing stations within major population centers."

The spokesperson said that the state has installed PM10 filter instruments at its Inland Port, Lake Park and Bountiful Viewmont stations. The division plans to put two more PM10 filter instruments in Brigham City and Farmington Bay.

The goal of these new instruments is to ensure "long-term monitoring of communities closest to the GSL so that we can better assess if PM10 is increasing and measure the composition of the [particulate matter] making it to these communities," the division's statement added.

Dust from the Great Salt Lake "could be extremely bioavailable and still not cause harm if the concentrations that people are being exposed to are relatively low or infrequent," Perry said, "but we don't know that."

A second study had similar results

Another study, published in Frontiers, used a "more simplistic" way of looking at bioavailability, Fernandez said.

Researchers extracted sediment from six sites along the south arm of the Great Salt Lake and the Weber River, which spills into the lake through the Ogden Bay Waterfowl Management Area.

They used two methods to extract soil -- one that mimicked the low acidity of lung fluid during inhalation and another that used strong acids to dissolve almost all elements that could become available in sediments, sludges and soils.

The extraction using lower acidity represented the same kind of bioavailability testing in the first study, Fernandez said.

The second is important because the more acidic an environment, he said, the more potential for harm.

Even using the extraction process with acidity similar to what's in our lungs, he said, the researchers found the same potential for negative health effects and levels exceeding federal standards.

The study also looked at the concentration of copper, thallium, arsenic, mercury, lead and zinc. Those metals historically have been deposited in the region and, according to the research paper, are "toxic when at high concentrations."

It found most metals are less concentrated than they've been in the past with some exceptions.

Copper levels remained elevated and were "relatively consistent" across sample areas, the report says, and arsenic also was still elevated with "significantly higher" concentrations in parts of Gilbert Bay to the west of Antelope Island.

Copper is an essential mineral but chronic exposure to high levels of it can result in liver damage and gastrointestinal symptoms, according to the National Institutes of Health.

Long-term exposure to high levels of inorganic arsenic can cause cancer and skin lesions and has been linked with cardiovascular disease and diabetes, according to the World Health Organization.

Levels of thallium -- a metal that can harm the nervous system, lungs, heart, liver, and kidney when people eat or drink large amounts in a short time -- also remain elevated, though the study didn't note where. Lead and zinc were higher in Weber River compared to sites in the south arm of the lake, the report adds.

(Francisco Kjolseth | The Salt Lake Tribune) The Great Salt Lake showed signs of improvement on Wednesday, April 12, 2023. Near the outflow of the Weber River, where areas that used to be bone-dry just weeks earlier, the lakebed was covered with a few inches of water, which reduced dust.

Researchers wrote that the study found regulatory measures are helping reduce the amount of potentially harmful chemicals in the dust and that different portions of the lake bed have different chemicals.

They add there are several unanswered questions about how the lake losing water and subsequently gaining salinity affect where metals are in the lake bed.

"As water-policy strategies are implemented in the coming years and lake elevation waxes and wanes it will be important to continue to monitor metal levels to see how they are affected," the report reads.

Utah needs more research, more water to the lake

Though the studies give researchers an indication of how materials within the dust could react with the lining of a person's lungs, they don't directly link dust events with negative health outcomes.

The state needs a larger, epidemiological study, Kelly said, looking at emergency room visits, asthma inhaler use and other health outcomes during dust events.

Those "tend to be expensive and take a long time," she said, but the state needs research to see what elevated levels of iron, copper, manganese and other transition metals in the playa dust do beyond inflaming the lungs.

There's also a need for research linking dust samples to the air in the Salt Lake Valley and surrounding areas, Kelly said.

Researchers took dust samples directly from the ground, she said. Ideally, a subsequent study should use samples from the valley and look at wind direction and composition to figure out where the dust originated and where it's going, she said.

There's some limited evidence that dust tends to blow toward the northwest side of the Greater Salt Lake area, Kelly said, but there haven't been a lot of measurements north of the city.

"We don't have samplers where this dust is going, like to Syracuse and Ogden and Layton," Perry added.

There's a clear need for more studies, Fernandez said, and efforts to help teachers convey the information we've already garnered through research.

The Division of Air Quality is funding a University of Utah study focused on evaluating how declining water levels increase dust emissions from the exposed lakebed and simulating dust transport to estimate the effect on air quality, including potential health risks, the agency said in an emailed statement.

"We have interest in funding similar studies as well as helping quantify the health impacts of Utah dust, and are working to find the budgetary capacity to specifically address these concerns," the division said.

(Francisco Kjolseth | The Salt Lake Tribune) Brine shrimp that thrive in the salty water of the Great Salt Lake can be harvested from large slicks full of eggs that float on the surface as pictured on Thursday, July 11, 2024.

Meanwhile, all three researchers expressed the same hope for the reaction to their research: More efforts to get water to the Great Salt Lake.

"Obviously, the hope is that we protect the lake in a way that we don't make it worse," Fernandez said.

Managing dust generally doesn't work well, Kelly said, and isn't cost-effective, meaning the best way to tackle it is to get water back in the lake.

Covering the exposed lakebed with water removes the threat of harmful dust, making better air quality a "co-benefit" of saving the Great Salt Lake, Perry said.

Two consecutive winters with lots of snow have bolstered the Great Salt Lake up past historic low levels, Perry said, but "if we move back into a dusty phase this is going to be a big problem again."

Megan Banta is The Salt Lake Tribune's data enterprise reporter, a philanthropically supported position. The Tribune retains control over all editorial decisions.