Be on the lookout for a scum-looking substance in bodies of water this summer.

Water that contains blue-green algae, also known as cyanobacteria, can pose a health risk, especially in young children, the elderly and pets.

“Prevention is better than cure. That is why we provide recommendations and advise to avoid all contact with blue-green algae,” said Michael Zakhary, a medical officer of health with Alberta Health Services (AHS). 

Blue green-algae is naturally occurring and appears when weather conditions are calm and warmer, generally from July to September in Alberta. Wind can push the bacteria from one side of a body of water to another. 

Common health risks to blue-green algae exposure include: 

  • Skin irritation 
  • Rash
  • Sore throat
  • Sore red eyes
  • Swollen lips
  • Nausea 
  • Vomiting
  • Diarrhea
  • Fever

“In very rare cases it could be severe, but this is very, very rare. It could affect the nervous system and it could affect the liver.”

AHS advises people who come in contact with the algae to rinse off with tap water immediately. 

Dogs and animals should also not come into contact with the bacteria as it can cause extreme sickness or be fatal.

Zakhary suggests people do not eat the fish from water contaminated with blue-green algae. 

To learn which water bodies are unsafe, you can visit the AHS website.