Blue-green algae blooms can release harmful toxins into the air

Cyanobacteria, or blue-green algae, released harmful toxins and deplete oxygen levels in the lakes and ponds where they bloom. Photo by Pixabay/CC
Cyanobacteria, or blue-green algae, released harmful toxins and deplete oxygen levels in the lakes and ponds where they bloom. Photo by Pixabay/CC

April 2 (UPI) -- For the first time, scientists have observed the release of blue-green algae toxins into the air.

Traces of the algal toxin anatoxin-a, or ATX, sometimes called the Very Fast Death Factor, were measured at a Massachusetts pond that frequently hosts large algal blooms.


Scientists reported the discovery in a new paper, published Friday in the journal Lake and Reservoir Management.

ATX is produced by cyanobacteria, a type of photosynthesizing bacteria. Though not technically algae, cyanobacteria is often called blue-green algae.

ATX has been blamed for the deaths of livestock, waterfowl and dogs. Acute exposure can cause loss of coordination, muscular twitching and respiratory paralysis.

"ATX is one of the more dangerous cyanotoxins produced by harmful algal blooms, which are becoming more predominant in lakes and ponds worldwide due to global warming and climate change," lead author James Sutherland, an environmental scientist with the Nantucket Land Council, said in a news release.

Though airborne algal toxins had never been measured before, Sutherland and his colleagues hypothesized algal blooms could release toxins into the air under certain conditions.

During the late summer and early fall in 2019, researchers regularly collected air samples using a glass fiber filter at the edge of Capaum Pond on Nantucket Island in Massachusetts.


Scientists screened for an array of toxins using an analytical technique called liquid chromatography-tandem mass spectrometry. On a windy but foggy day, several samples revealed the presence of ATX in the air.

Researchers measured concentrations as high as 21 nanograms of ATX per milligram of air, and captured an average of 0.87 nanograms of ATX in each filter.

It's likely that brisk winds helped the toxins get airborne, while the surrounding fog prevented the toxins from being dispersed beyond detectable levels by the wind.

Scientists aren't sure how exactly the toxins are becoming airborne, whether the ATX molecules are enveloped in aerosolized water droplets or attaching themselves to other aerosolized particles.

It's also possible the cyanobacteria cells themselves are becoming airborne, they said.

No matter how it's happening, researchers say the phenomenon is a threat to the health and safety of humans and wildlife.

"People often recreate around these lakes and ponds with algal blooms without any awareness of the potential problems," said Sutherland.

"Direct contact or inhalation of these cyanotoxins can present health risks for individuals, and we have reported a potential human health exposure not previously examined," said Sutherland.

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