Airborne algae: Scientists near Lake Erie study health impacts on people

Most people living near Lake Erie are all-too familiar with warnings about blue-green algae blooms.

Don’t swim in it. Keep your pets out of the water. And definitely don’t swallow it.

Coming into contact with algae blooms can cause things like a rash, sore throat or red eyes.

But there’s another way you could be exposed — and it has nothing to do with physically getting into the freshwater system.

Scientists are studying what happens when algae becomes airborne, and we breathe those particles into our lungs.

David Kennedy is a professor of medicine at the University of Toledo. He also leads the Great Lakes Center for Freshwater and Human Health, which oversees the American-led study.

For roughly the past two and half years, researchers have been trying to pinpoint how the toxins, when airborne, impact people’s health. Phase one of the analysis is expected to last five years. 

The Great Lakes Aerosol Monitoring Research Study (GLAMR) hasn’t gone through peer review, nor has it been published. It tracks people who either live, work or recreate in the area of the western basin of Lake Erie.

“We want to understand … what does this do to normal healthy people, but potentially are there people who are at risk who may be more susceptible to these toxins?” said Kennedy.

“I guess intuitively people who spend more time around a harmful algal bloom can report more symptoms. But this is really sort of nuanced. I think it’s really important.”

Anyone is eligible if they either live, work or recreate in the area, no matter if they’re American or Canadian.

The study is about midway through its first phase in what Kennedy calls a long-term clinical process.

So far, about 200 people have given samples and are being tracked — or about 75 per cent of their participant goal.

“At this point, the only thing that we can really say is that we definitely know that there are people who are more responsive and less responsive to those toxins.”

“There’s a lot of variability with humans … I guess that’s really what we want to understand that it’s important because if you think about it — if we understand who’s more susceptible — that’s good in a sense for public health.”

The scientists involved say the study is a concerted and focused effort bringing together air and water experts — combined with medical professionals.

Kennedy says participants are essentially providing a biopsy from a little brushing of the cells from someone’s nasopharynx.

“We grow those up in a way that helps mimic … how the lung cell acts and behaves. We certainly don’t want to cause widespread panic or fear. At the same time, there’s some public health aspects of this that we think are really important.”

Participants are asked to inform the study how they feel during the peak bloom season, but also when it’s not that time of year.

Blood and urine samples are collected, as well as exhaled breath and nasal cavity swabs and cell samples.

“[Short term] there really is no mystery about inhaling or drinking large quantities of toxin. Those effects are seen really very quickly and immediately. One of the major questions that we have is what happens for long-term exposure?”

‘August cough’

Algae, and in particular the toxins that they make, can be trapped in bubbles and aerosolized, according to Gregory Dick.

He’s the director of the Cooperative Institute for Great Lakes Research at the University of Michigan. 

“They can get up into the air when waves break or jet skis or motorboats are moving through the water,” Dick told CBC News. 

“That happens much like in the winter cold season or with COVID. We think of aerosolized viruses [while] we can have aerosolized cyanobacterial toxins, too.”

The toxins can travel many kilometres, he says, and remain in the air for some time. Attempts to further define those measurements continue.

“They could be an issue not just if you’re on the lake, but also a concern for coastal communities as well. We would expect that the concentration of the toxins would decline with distance.”

Although hard to distinguish, the symptoms in some cases are similar to asthma, he says.

“Often these manifest in the summer time when we have these blooms. There’s actually something that some of the boaters and fishermen and Lake Erie call ‘August cough.’”

University of Michigan chemistry professor Andrew Ault says although long-term health data for airborne algae doesn’t exist yet, it’s still known that breathing in toxins can be worse than ingesting them.

“If you drink the water — even if it’s got the bad stuff in it — our bodies [are] relatively used to ingesting some bad stuff,” he told CBC News. 

“If we breathe in, even the same thing in the same amount, our lungs are just much more sensitive.”

Ault says the cyanobacteria can stay in the air for days to weeks. That’s one of the things they’re hoping to better define during this research.

The topography around Lake Erie could also help move around airborne algae from the lake, he says.

“It’s really flat. That makes it easier … to get transported for sure. A lot of people live around the Great Lakes, so that’s why it matters.”

Ault says water, in a way, can also be more easily controlled than the air.

“We can put dams up, we can do things, but air is going to go where it’s going to go. If it gets emitted in Toledo and ends up over Windsor or further up in Ontario … that’s a lot harder to control. It’s much better to mitigate the source than to try to do something about it after the fact.”

Ault hopes the study ends up offering communities a better sense of how hazardous the air can be.

“I am hoping that we will be able to say this is a day where if it’s really windy right next to the beach, you might not want to walk next to the beach today.

“If you’ve got an air cleaner in your house … this is a day to turn your air cleaner on.”