New research shows two additional routes that toxic metals in dust blown off of the Great Salt Lake could move into soils, plants, and human bodies.
"No, it's definitely not just an inconvenience," said Janice Brahney, associate professor of environmental biogeochemistry.
Brahney supervised new research led by Molly Blakowski at Utah State University this spring.
“The Great Salt Lake is a terminal basin with multiple millions of people that live in the catchment, lots of industry, lots of activity in the catchment," she said, "so everything that we do, everything that we create, all the toxins we produce, all the different compounds, they all flow into the Great Salt Lake."
Many of those contaminants accumulate in lakebed sediments. However, as lake levels drop, more of the lakebed is exposed to wind. That exposed sediment, some of which may carry toxic metals, can become dust, which people can inhale.
Brahney said many people think about dust mostly in terms of very small particles, known as PM 10, because they have a diameter of less than 10 microns. That miniscule size can get into the lungs.
But her team was also interested in larger particles, because those can still enter the body.
“Often what happens when you inhale particles that are larger than 10 microns is that you swallow them,” she said.
To test what happens to swallowed particles, they collected dust from the exposed lakebed and introduced it to stomach acid in the lab.
They found fairly high concentrations of some toxic heavy metals dissolved in that acid, meaning the body could absorb the metals if swallowed. The team also tested whether dust could contaminate food crops.
In one experiment, they applied Great Salt Lake dust to cabbage while it was growing.
“We did quite thorough washing of the plants, and we still found higher concentrations of certain metals taken up into the plant tissue,” Brahney said.
These findings show the problem is not only limited to dust entering peoples’ lungs but also can be absorbed by eating produce that has the Great Salt Lake dust on it. And for children, who are smaller and less able to tolerate the same exposure as adults, the concern is even greater.
