Earlier this month an Urbana resident became ill after swimming in Clinton Lake due to the presence of blue-green algae in the lake. The algae produced a rash and flu-like symptoms for the girl.    

“Illness due to blue-green algae toxin is not common. Human death due to blue-green algae is not likely, but can occur in extremely rare instances,” Januari Smith, spokesperson for the Illinois Department of Natural Resources, explained.

“Although there is no confirmatory test for blue-green algae toxin, you should contact a physician [if possibly exposed to blue-green-algae]. Your doctor will treat the symptoms and the body will eventually purge the toxin. The duration [of the illness] depends on the amount of toxin ingested and the person’s weight, medical condition, etcetera,” Smith added.

Blue-green algae can cause a variety of different symptoms depending on the organism exposed.

“Some of these toxins cause muscle paralysis, others may kill cells in major organ systems, such as the liver, promote tumors, or cause dementia. Not as much is known about toxins that might affect swimmers who ingest or inhale them while swimming, and report gastrointestinal problems or rashes,” Martha Cook, associate professor of botany, explained.

On July 15, the Illinois Department of Natural Resources issued an amended advisory explaining that samples had no to very low levels of toxicity in Clinton Lake.

The IDNR still recommends that the public refrains from using lakes with high levels of algae for recreational purposes.     

According to the advisory, “The IDNR and the Illinois Environmental Protection Agency are continuing to review sampling data collected at Clinton Lake, but test results received so far show low levels of the type of algae that would cause concern for public health.”

Even though humans are susceptible to these toxins, fish seem to be unaffected, and it should be safe for humans to eat wildlife that come out of bodies of water with high levels of algae. The only known animal to pass the toxins on to humans after consumption are Guam fruit bats, and there are no known similar issues in this region, Cook added.

“Blue-green algae and other algae can become abundant if excess nutrients [such as fertilizers] are put into the water. These can come from lawns or farms, and it is important to keep them out of the water because an abundance of algae and the bacteria that are breaking [the algae] down when they die use up all the oxygen in the water, making it impossible for most organisms to live there,” Cook said.

Cook explained excess nutrients and heat cause an abundance of algae to grow and the algae eventually will die. When the algae die, the algae’s toxins seep into the water.

“Blue-green algae are also known as cyanobacteria because of their blue-green photosynthetic pigments.

“The bacteria are among the oldest organisms on Earth. Oxygen from their photosynthesis produced our oxygen atmosphere,” Cook said.