HEALTH

Toxins found blue-green algae blooms could be in the air all the time, researchers say

Treasure Coast Newspapers

Toxins produced by blue-green algae may be in the air pretty much everywhere and pretty much all the time, according to new research by a team from Yale and Florida Gulf Coast universities.

The toxins "may always be in the air," research team leader Michael Parsons said of microcystin, which has been linked to liver disease and BMAA. Some scientists think BMAA could lead to neurological diseases such as ALS, Alzheimer's and Parkinson's.

More: Ohio State University study links toxic algae blooms and liver disease

More: Health risks of blue-green algae toxins unknown, scientist says

"If that's the case, humans have been exposed to them since time began and, therefore, have adjusted to low levels of the toxins," said Parsons, a FGCU marine science professor who's conducted other studies on harmful algal blooms.

How much is too much?

The question, Parsons said, is: How much exposure to the toxins is enough to cause health problems?

The World Health Organization says "recreational" contact with water containing microcystin at 10 parts per billion is hazardous.

But nobody has determined what level of microcystin in the air is hazardous to breathe," Parsons said. "And we don't know how long you'd have to breathe it. Is it 10 minutes or 10 years?"

More:Water in St. Lucie River 10 times too toxic to touch

During the height of the 2016 algae blooms in the St. Lucie River, a study by Martin County found microcystin in the air at Central Marine in northern Stuart.

More: Tests show blue-green algae toxins contaminating air

Protesters wearing protective masks listen to U.S. Rep. Patrick Murphy during his visit to Central Marine in Stuart on Sunday, July 10, 2016. The visit came in the midst of last summer's toxic blue-green algae blooms. A report released Wednesday by the American Civil Liberties Union says Florida officials did a poor job warning residents about the potential health hazards caused by the bloom.

To understand the exposure risks, Parsons said, "is going to require medical research like inhalation tests on rats or mice to see at what concentrations of the toxins and for what lengths of time do we start seeing liver damage."

Preliminary results of a study on those who live and work around algae blooms in the St. Lucie River, all of the first 70 people tested had "detectable levels" of the toxin microcystin in their noses, according to Adam Schaefer, an epidemiologist at Harbor Branch Oceanographic Institute at Fort Pierce.

More: People along St. Lucie River breathing toxin, study says

"Preliminary results suggest microcystin is definitely airborne," Schaefer told TCPalm in September as people were giving blood, urine and nasal swab samples for the study.

Florida Atlantic University's Harbor Branch Oceanographic Institute researchers (from left) Chris Campbell, volunteer RN, Adam Schaefer, epidemiologist, and Dr. Kathi Harvey, of Harbor Branch and the FAU College of Nursing, collect blood, urine and nasal swab samples Friday, Sept. 14, 2018 at the Florida Sportsman magazine office in Stuart. The group is testing people who live and work around blue-green algae blooms in the St. Lucie River and have found detectable levels of the toxin microcystin in the noses of over 70 people tested. "Preliminary results suggest that microcystin is definitely airborne," Schaefer said. Schaefer, the lead researcher on the project, hopes to test people who have not been exposed to algae for a control group and to expand the testing to Lake Okeechobee and Florida's West Coast, but more funding is necessary to collect the data needed for a long-term study on microcystin exposure.

Parsons' study also found particles of microcystin and BMAA were small enough to enter people's lungs, giving the toxins "access to the respiratory pathway to the bloodstream."

Scientific method

For their experiment, researchers measured similar levels of both microcystin and BMAA in the air from Sept. 21 to Oct. 11 at two sites:

A home on a dead-end canal Cape Coral

An aerial view of a toxic algae bloom is shown flowing into a canal in Cape Coral during the summer of 2018.

The canal had a thick blue-green algae bloom, a lot like the thick mats of "guacamole" blooms covering much of the St. Lucie River in the summer of 2016.

Researchers noted the bloom had peaked earlier in the year and was diminishing during the sampling period.

About 30 miles to the south at FGCU's Vester Field Station in Bonita Springs

The site is on water that contained blue-green algae but no visible bloom.

The researchers found:

Nearly identical levels of microcystin and BMAA in the air at both sites
Both toxins in the water at both sites, but much lower levels at the Bonita Springs field station

Researchers checked weather reports and found predominant southeast winds during the sampling period, so wind couldn't have blown the toxins from the bloom in Cape Coral to the site in Bonita Springs.

During a second round of sampling in the dry season, from Dec. 21 to Jan. 18, they also found both toxins in the air — although at much lower levels than before — at the FGCU campus in Buckingham, east of Fort Myers and more than a mile from any body of water.

More: Read the Florida Gulf Coast/Yale report

Noting the research took place as the blooms were waning and after they were gone, Parsons plans to continue the study in the summer if algae blooms reappear.

"We need to make more measurements to see just how high the levels of toxins in the air can go," he said.