Area health officials have lifted the ban at Getty's Beach and Pier Road Beach in Wheatley, following blue-green algae concerns.
Tests at the Hillman Marsh Beach near Leamington are not yet complete.
Health officials were at the beaches testing water for E.Coli bacteria when they found the bloom. The water was being tested for the presence of the toxin microcystin. It's been found that the cyanobacterial bloom has dissipated.
However, acting medical officer of health for Windsor-Essex Dr. Wajid Ahmed says you can have a algae blooms without microcystin. "The bloom has all those toxins in there, but most commonly those toxins are released when the algae is dying." He says it's also possible other toxins will be present.
Residents living near Hillman Marsh Beach are asked to stay out of the water and to keep their pets away.
Coming in contact with microcystins can cause skin and eye irritation. If swallowed, it can cause headaches, fever, abdominal pain, nausea and vomiting. Ingesting large quantities can also cause liver damage.