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Blue-Green Algae

If you suspect a blue-green algal bloom, call the Spills Action Centre at 1-800-268-6060

For information on the health risks associated with blue-green algal blooms, please contact Health Connection at 705-721-7520 or toll-free at 1-877-721-7520 to speak with a public health inspector.

The Ministry of the Environment, Conservation and Parks (MECP) collects and tests algae samples and reports the results to the health unit.

Waterways Affected by Blue-Green Algae:

2018

Affected Waterway
Municipality
Date
Three Mile Lake
Muskoka Lakes
July 31, ‚Äč2018
Clark Falls - Lake Rosseau Muskoka Lakes
August 17, 2018
Boyd Bay/Indianhead Harbour
Muskoka Lakes
August 21, 2018
Lake St. John Ramara Township
August 31, 2018
Magnus Park-Georgian Bay Tay Township September 14, 2018
Leonard Lake Muskoka Lakes
September 14, 2018

 

What is Blue-Green Algae?

Blue-green algae, technically known as cyanobacteria, are microscopic organisms that are naturally present in lakes and streams. They are usually present in low numbers but can rapidly increase in warm, shallow, undisturbed surface water that gets a lot of sun. When this happens, they can form blooms that discolour the water or produce floating scum on the surface of the water. Blooms often make the water look blue-green or olive-green, or like green pea soup or turquoise paint.

What Are the Potential Health Effects from Drinking or Coming in Contact with Blue-Green Algae?

Some blue-green algae produce toxins (Government of Canada) can pose a health risk to people and animals when they are exposed to them in large amounts. Your health may be impacted when surface scum or water containing high levels of blue-green algal toxins are swallowed, come into contact with the skin, or when airborne drops containing toxins are inhaled while swimming, bathing or showering.

Consuming water

Ingestion of high levels of blue-green algal toxins have been associated with effects on the liver and nervous system in laboratory animals, pets, livestock and people. Livestock and pet deaths have occurred when animals consumed large amounts of algal scum.

Direct contact, or breathing airborne droplets

Coming in contact with high levels of blue-green algal toxins while swimming or showering can irritate the skin, eyes and throat and inflame the respiratory tract.

Recreational contact

Swimming and household contact, such as bathing or showering, with water not visibly affected by a blue-green algae bloom is not expected to cause health effects. However, some individuals can be especially sensitive to even low levels of algal toxins and might experience mild symptoms such as skin, eye or throat irritation or allergic reactions.

How Can I Avoid Exposure to Blue-Green Algae?

Never drink untreated surface water, algae blooms are present or not. Untreated surface water may contain other bacteria, parasites or viruses, as well as algal toxins that could cause illness if consumed.

People not on public water supplies should not drink surface water during an algal bloom, even if it is treated. In-home treatments such as boiling and disinfecting water with chlorine or UV and water filtration units do not protect from blue-green algal toxins.

People, pets and livestock should avoid contact with water that is discoloured or has scum on the surface. If contact does occur, wash with soap and water or rinse thoroughly with clean water to remove algae.

Stop using the water and seek medical attention if symptoms such as skin, eye or throat irritation, allergic reactions or breathing difficulties occur while in contact with untreated surface water. However, swimming, bathing or showering with water not visibly affected by a blue-green algae bloom is not expected to cause health effects.

Do not eat the liver, kidneys and other organs of fish caught in the water body. Be cautious about eating fish caught in water where blue-green algae blooms occur.

What Shoud I Do if I Suspect Blue-Green Algae?

If you suspect a blue-green algal bloom, be cautious and assume that toxins are present.  Avoid exposure to the blue-green algae.

If you spot a bloom, report it to the Spills Action Centre at 1-800-268-6060

For information on the health risks associated with blue-green algal blooms please contact Health Connection at 705-721-7520 or toll-free at 1-800-721-7520 to speak with a public health inspector.


For more information:

Adapted with permission from Public Health Sudbury & Districts
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