The Great Salt Lake “not so far” from an ecosystem collapse: toxic dust storms, imminent deaths

0

Kentucky bluegrass adds a touch of green to the dusty landscape of northern Utah, an area with low summer rainfall. Yet despite sky water scarcity, Utahans use more water per person than almost anywhere else in the country – and only a quarter of that water makes it inland.

Two decades after a mega-drought began, water irrigation is keeping manicured lawns and fields alive in the middle of the desert. Yet dust storms have become a growing problem for human health and ecosystem health. Only a brackish crust and sparse plants may soon remain of the Great Salt Lake. This is because as water levels drop in the shallow terminal basin, heavy metals and toxins accumulate in their place in the old lake bed. Now, experts fear that dust accumulated in the dry lake – some of which is toxic – is blowing through the area, potentially entering the bodies of people living there in the process.


Want more stories about climate and science in your inbox? Subscribe to Salon The Vulgar Scientist’s weekly newsletter.


Human activity has already led to a generally dustier world, but in naturally dry climates the effect is amplified. The Great Salt Lake lies in the shadow of rain, which is at least partially responsible for the salinity of the lake; indeed, almost any moisture in the air precipitates before it even reaches more than 2 million people in metropolitan areas. Instead, residents of the Salt Lake region rely on snowmelt from the Wasatch Mountains, where much less snow has accumulated in recent winters. Another source of dust may seem insignificant, but along the Wasatch Front, where two-thirds of the state’s population live, the Great Salt Lake has the potential to add more dangerous contaminants to the mix.

“It’s on our doorstep, and when it blows, it impacts everyone along the Wasatch front,” Dr. Kevin Perry told Salon.

But just because the lake bed contains contaminants does not necessarily mean they will be blown into the environment. It depends on the erosion.

In 2016, the University of Utah atmospheric scientist set out to determine if brackish crust and vegetation would keep contaminants and sediment contained and hold toxic dust plumes at bay. Perry spent the next two years cycling through exposed areas of the crust to document potential “hot spots” where loose soil might be suspended in the air.

Utah was not spared from record heat last summer, and neither was the Great Salt Lake. The shallow terminal lake has shrunk to 950 square miles, nearly half its historic size.

In the drought-stricken state, officials often perceive water entering the Great Salt Lake as wasted water. The very salt that makes lake water unfit for human consumption can be a saving grace when it comes to trapping its dust and contaminants. While other dry lake beds, called beach, often become important dust generators, the Great Salt Lake remains an exception. Unlike most other beaches, which generally have no salt crust, the sediments of the Great Salt Lake remain, for the most part, in the ground.

With historically low water levels in rivers and streams, Utah has experienced drought for eight of the past 10 years. Utah was not spared from record heat last summer, and neither was the Great Salt Lake. The shallow terminal lake has shrunk to 950 square miles, nearly half its historic size. As Utah prepares for another summer of extreme drought, experts expect the Great Salt Lake to hit a new record soon.

With water levels remaining low on the Great Salt Lake, thinner areas of the crust become more susceptible to erosion. If the trend continues, 22% of the natural salt crust could disappear, and lake dust could become a real problem. In an assessment prepared for the Utah Department of Natural Resources and the Utah Division of Construction and Facilities Management in 2019, Perry reported that only 9% of the exposed lake bed was hotspots at the time.

Since then, graduate students working with Professor Brahney have been monitoring the situation on the ground. According to Ph.D. student Molly Blakowski, trouble spots have multiplied in recent years.

Even at lower levels, the dust poses a health hazard to people with respiratory diseases such as asthma. When strong winds lift a lot of fine sediment, smaller particles can enter the bloodstream of those who inhale them.

“These sites are getting dustier and dustier, and last year was by far the dustiest year in our study,” Blakowski claimed in an interview with Salon. “I have no reason to expect this year not to be the same or worse.”

Even at lower levels, the dust poses a health hazard to people with respiratory diseases such as asthma. When strong winds lift a lot of fine sediment, smaller particles can enter the bloodstream of those who inhale them. For this reason, the Environmental Protection Agency sets limits on particles measuring 10 microns or smaller – less than half the size of a human white blood cell.

Blakowski added, however, that the Great Salt Lake dust particles are mostly about 30 microns in size. Although the exact health effects of exposure remain unknown, these dust plumes can make the air quality unbearable, forcing people to take shelter indoors more often and decreasing the overall quality of life.

Utah State University professor Janice Brahney, who is advising on Blakowski’s research, told Salon the danger was related to the proximity of the Great Salt Lake.

“Millions of people who live in the watershed contribute pollution that flows into the lake and can bind to sediment,” Brahney said. “It also means that those same people are exposed to dust when it’s produced in the toxins that are in that dust.”

Not only does runoff from metropolitan areas also carry contaminants, but it may well fuel the synthesis of other toxins in the lake itself. Algal blooms that grow on agricultural and industrial waste in the Great Salt Lake harbor bacteria that produce cyanotoxins have become increasingly prevalent. At the Environmental Biogeochemistry and Paleolimnology Laboratory, Dr. Brahney and her colleagues found that cyanotoxins in the lake bed can also enter residents’ lungs.

Already home to over 1.2 million people, the Salt Lake City metro area alone accounts for one-third of Utah’s population and will likely double by 2060, both contributing to the problem and suffering the consequences. Still, it’s unclear what health effects more frequent exposure would have on residents. Brahney stressed that a growing list of contaminants should nonetheless spur action.

Although the drought has put a heavy toll on the lake, the problem is largely man-made. Without the current diversions, it is estimated that the Great Salt Lake would be 11 feet higher. According to Zachary Frankel of the Utah Rivers Board, the diversion of the Bear River, making it the last major water source for the Great Salt Lake, would ensure that it dried up completely.

“The proposed diversion of the Bear River upstream from Great Salt Lake would be the real knife in the patient,” he told Salon.

The Bear River development has remained merely a proposal since lawmakers approved it in 1991, but millions of dollars are spent each year to keep it moving forward, despite the ramifications of the project.

The drying in the Great Salt Lake also contributes to a larger feedback loop in which less snowfall creates less snowfall. The dust itself contributes to additional drying.

When dust settles on snow, it makes it darker. Because darker snow can absorb more sunlight instead of reflecting it, it warms up faster and melts sooner. With less surface, there will also be less “lake effect snow”, as the phenomenon is called. Both impacts are detrimental to water resources and a ski industry that heralds the “biggest snow on Earth”.

Similarly, the artemia industry is threatened by the drying up of the lake. For Utah, brine shrimp are a vital source of revenue. Already, the state’s brine shrimp industry, the largest in the world, is under strain. As water levels continue to drop, salinity will soon reach levels that will make the lake uninhabitable for salt-tolerant brine shrimp and flies.

“We’re not that far from a tipping point where the southern part of the lake will become so salty that the brine shrimp can’t survive,” Perry said, adding that an “ecosystem collapse” would follow. .

Perry expects that mass mortality not only for the lake’s salt-tolerant species, but also for some 10 million migratory birds that feed on it would be likely. Native plants and animals are already struggling to survive, and climatologists expect the American West to become drier as the Earth warms. Climate change has already contributed to later snowfall, earlier melting and lower accumulation.

Although ranking second in the nation behind Idaho in municipal water consumption per person, Utah is pretty average when it comes to overall water consumption. Municipal use accounts for only 10% of the state’s water supply, while 85% is used for agriculture. Growing alfalfa takes a particularly large sip of the water supply, but as Dr. Wayne Wurtsbaugh noted in an interview with Salon, there is no water quality standard to protect the water supply. water itself.

“You can take all the water out of the creek and decimate all the organisms in it, and it doesn’t matter in terms of water quality,” he explained, pointing out a major flaw in EPA standards.

Read more

on water and climate change

Share.

Comments are closed.