The Simcoe Muskoka District Health Unit is advising people to stay out of the water in three lakes in Muskoka because of the potential health risk posed by bacteria.

The Ministry of Environment conducted laboratory tests confirming blue-green algae blooms in Three Mile Lake, in the Boyd Bay area and the Clark Falls area of Lake Rosseau.

Wind and water currents can change the location of algae blooms which may make the water look bluish-green, or like green pea soup or turquoise paint.  Caution is, therefore, advised around both lakes.

The bacteria can cause skin rashes and gastrointestinal problems.

The health unit says swimming and other water sports activities should be avoided in areas where the blue-green algae bloom is visible.

Health officials say residents should avoid using the lake water for drinking or food preparation, including breastmilk substitute (infant formula).  Officials say boiling the water will not destroy the toxins, and home treatment systems should not be relied on.

The health unit will continue to monitor the lakes.