Toxins from harmful algal blooms are well known as water polluters, but researchers are now examining how they affect the air in the Great Lakes.
And that could have implications for human health, they say.
Water particles emerge into the air when waves break, said Andrew Ault, professor of chemistry and aerosol researcher at the University of Michigan. These particles sometimes contain toxins.
“It’s one of the biggest sources of particles released to the atmosphere globally, but the Great Lakes are really different,” Ault said.
But people shouldn’t panic about airborne algae toxins, he said. Still, it doesn’t hurt to be careful, such as not walking through an algae bloom or participating in recreational activities nearby, Ault said.
Scientists have studied particles emerging from the ocean for decades, he said. But freshwater aerosols, like those from the Great Lakes region, have only been studied for about ten years.
Aerosols are liquids or solids suspended in gas, said Haley Plaas, a doctoral student and aerosol researcher at the University of North Carolina at Chapel Hill. For example, COVID-19 can be spread through aerosols, and this is one of the reasons people wear masks.
Plaas published a study on airborne toxins from algal blooms in the journal Environmental Science & Technology.
The most important finding of her study is that the evidence suggests that harmful toxins and the algae itself are found in the air, she said, and that airborne algal toxins could constitute a greater threat to the Great Lakes than previously thought.
Scientists don’t know how many toxins are in the air, how weather conditions and water quality affect it, and how they can affect human health, Plaas said. At this time, more research is needed to understand what inhaling this toxin could mean for respiratory health.
“One of the main concerns is with the people who live near these bodies of water who experience the flowers, as well as the people who use it for recreational purposes, such as jet skiing, boating, fishing. “said Plaas.
A boat’s wake is particularly troublesome because it’s a source of bursting bubbles that can cause toxins to lift off, she said.
Ault has published several articles on aerosols and is working on one that shows toxins from algae in the Great Lakes entering the air.
He said he plans to work with engineers and modelers to develop a risk system to help people avoid poor air quality due to algae blooms.
Then he said he would like to work with epidemiologists to link exposure to health. “That’s kind of the trajectory that we see it going,” Ault said.
The lack of research on harmful algal blooms and air quality is in part due to insufficient funding, he said.
“We have to show that it’s important that people are excited about funding it,” Ault said. “We’re going through this cycle, but I wouldn’t say the funding agencies have paid much attention to it yet. “
Funding comes mostly from local rather than national agencies, he said.
Algal blooms occur due to global warming and nitrogen and phosphorus runoff from activities such as agriculture, said Judy Westrick, a professor of chemistry at Wayne State University and a researcher who worked with Ault.
In the Great Lakes region, algal blooms occur in inland lakes and the western basin of Lake Erie, mostly in shallow water, Westrick said.
The research is focusing on the water quality because of the observations, she said. When people got sick after swimming in toxic water, scientists began to research it.
However, now that water quality is better understood, scientists are embarking on understanding toxins in algae and in the air, Westrick said.
“You’re probably going to see, probably next year, a hundred aerosol studies,” Westrick said. “Aerosols have become very important because of several factors. “
The factors are part of climate change, she said. For example, heavy precipitation can cause waves and break up harmful algae, releasing particles that could be toxic into the air.
Westrick and Ault plan to study living seaweed broken by waves and its impact on air quality, she said. Once the algae breaks down, it dies and can release toxins into the water.
The expert consensus is that algal blooms will worsen as climate change and runoff worsens, Westrick said.
Algae feed primarily on nitrogen and phosphorus from agricultural runoff.
“If you take care of the nutrients and you don’t have the nutrient load, then they won’t get worse, but if everything stays the same, the nutrient load, and it’s just warmer, we expect them to last longer. “Westrick said.
Reporting by Hannah Brock for Great Lakes Echo.