BGSU researcher discovers presence of dangerous airborne neurotoxin near Great Salt Lake

Dr. James Metcalf found the reduction of the Great Salt Lake could have significant human health consequences, including potentially higher rates of ALS

By Nick Piotrowicz

The continuing reduction of the Great Salt Lake could have significant, long-term consequences for human health, according to pioneering new research from a Bowling Green State University environmental toxicologist.

Dr. James Metcalf, an associate professor of Biological Sciences at BGSU, teamed with Drs. Paul Alan Cox and Sandra Anne Banack of the Wyoming non-profit institute Brain Chemistry Labs to collect air and water samples from the Great Salt Lake during three months in 2022, the results of which showed an alarming result of water-level decrease. The samples indicated an increased presence of BMAA, an airborne neurotoxin highly correlated to increased levels of ALS, also known as Lou Gehrig’s Disease.

The Great Salt Lake has lost 71% of its surface area since 1984, exposing increasingly more lakebed – which likely has significant air quality implications for the greater region surrounding Salt Lake City, a metropolitan area with 2.5 million residents.

“In terms of public health, the fact that we’re exposing more lakebed could result in more toxins being made airborne, and more toxins being made airborne could result in more people being exposed,” Metcalf said. “Increased exposure may affect long-term diseases like ALS and Alzheimer’s.”

The research recently was published in the academic journal Toxins, and Metcalf presented the findings during a press conference in the Utah State Capitol building in Salt Lake City. 

To collect data, the research team employed a trained helicopter pilot in Ogden, Utah, to take them to sample multiple sites across the region during August, September and October of 2022. Following collection, they tested samples using mass spectrometry, which revealed a complex set of issues facing the Great Salt Lake.

Due to the nature of the region – an arid climate with a major city in a valley near the Rocky Mountains – smog from vehicle exhaust already has been an issue in Utah, but the research found an additional air quality concern.

“There were two things that were surprising,” Metcalf said. “One is that the toxins in the air and the toxins immediately below in the lakebed didn’t really match up, so it suggested that the toxin in the air may be coming from a broader swath of the lake as well. The second is that we were surprised at how much toxin was in some of those air samples.”

Metcalf’s research also has implications close to home for BGSU and the larger Great Lakes region. In 2014, cyanobacteria fed by agricultural runoff produced the toxin microcystin, which temporarily caused the city of Toledo’s water supply to be unsuitable for public consumption.

Understanding how these toxins operate, where they are liable to be found and how to mitigate their effects is critical to public health, Metcalf said. 

“We know from 2014 that cyanobacteria can really shut down these large lakes,” Metcalf said. “The research suggests that toxins like microcystin and BMAA are quite common in the environment, especially in the environments where nutrients and runoff are present, so we’re potentially exposed from a wide range of places and we need to understand what’s there. 

“We need to understand what’s in the air and what’s in the water.”

In the case of the Great Salt Lake, Metcalf said several factors have contributed to the decreased surface area and increased exposure of the lakebed. 

Because the Great Salt Lake is terminal – other waterways run into, but not out of, the lake – it is particularly susceptible to reductions from contributing factors like less snow and drought conditions exacerbated by climate change, and also from overuse of water by humans. 

Combined, these factors could be leading to an increase of airborne BMAA.

“Climate change will have a big effect on things like snowpacks that feed the Great Salt Lake, but secondly, it’s also about how we use water,” Metcalf said. “Water is a finite resource that we need to live. Perhaps we don’t need lush green lawns in places where lush green lawns are not suitable. The Great Salt Lake is in a desert, so I think people need to think about how we use fresh water, how we reuse wastewater and how we live our lives.”

Metcalf hopes to replicate the study near Lake Erie to compare the behavior of toxins in a different climate to better understand how they operate and how they can be mitigated. 

Though more information is needed, Metcalf said the results demonstrate the importance of protecting our natural resources.

“If we can protect environmental health, we can protect human health,” Metcalf said. “Those two things are so intertwined that if you protect one, the other benefits. We need to do more analyses, more samplings and more time points, but this research is a signal to say something might be awry.”