On the lookout for blue-green algae

File photo

Since 2006, 59 blue-green algae blooms have been confirmed in 26 bodies of water within the Sudbury & District Health Unit area. Again this year, the Sudbury & District Health Unit and the Ministry of Environment will be following up on calls received regarding blue-green algae.

Blue-green algae, technically known as cyanobacteria, are microscopic organisms that are naturally present in lakes and streams. They are some of the oldest life on earth and are usually present in low numbers. Blue-green algae can rapidly increase in warm, undisturbed surface water that receives a lot of sunlight. When this occurs, they can form blooms that discolour the water or produce floating rafts of scum on the surface of the water. Blue-green algae can be harmful to health in high quantities.

“Visible algal blooms may produce toxins at high enough levels to cause illness; therefore, using or drinking the water should be avoided,” said Allan McDougall, an environmental support officer with the Sudbury & District Health Unit.  “People do not usually drink water contaminated with blue-green algal blooms because of its unsightly pea soup appearance and foul smell.”

At high enough levels, the algae toxins can irritate a person’s skin and, if ingested, cause diarrhea and vomiting. If a person ingests large amounts of toxin, they could suffer liver and nervous system damage. The highest concentrations of toxins are usually found in blooms and scum on the shoreline. These dense accumulations pose the greatest potential risks to people and pets.

Blooms may be observed in any part of a water body. Since the blooms are not anchored, wind and water action can move them from one location to another.

The Health Unit advises anyone using area lakes and rivers to be on the lookout for algal blooms. If you see a bloom near your property or water intake line:

  • Avoid using the water for drinking, bathing, or showering, and do not allow children, pets, or livestock to drink or swim in the bloom.
  • Be aware that shallow drinking water intake pipes can pump in blue-green algae.
  • Do not boil the water or treat it with a disinfectant, like bleach, because it breaks open the algae cells, releasing more toxins into the water.
  • Avoid cooking with the water; food may absorb toxins during cooking.
  • Exercise caution with respect to eating fish caught in water where blue-green algal blooms occur. Residents should not eat the liver, kidneys, and other organs of fish caught in the water.
  • Do not rely on water jug filtration systems as they may not protect against the toxins.

On lakes and rivers where blue-green algal blooms are confirmed, people who use the surface water for their private drinking water supply may wish to consider an alternate, protected source of water.

For more information, please call the Sudbury & District Health Unit at 705.522.9200, ext. 398 or visit our website at www.sdhu.com.