News Releases

Cyanotoxins and Microcystin

Lisle, Illinois — The Water Quality Association has released an official statement on cyanotoxins such as microcystin, which was recently detected in the public water supply serving Toledo, Ohio.

What are cyanotoxins?
Certain varieties of freshwater algae known as cyanobacteria may be present in rivers, lakes and other bodies of surface water. When conditions are right, cyanobacteria (sometimes referred to as blue-green algae) can rapidly multiply in surface water causing harmful cyanobacterial algal blooms. Some species of cyanobacteria produce toxic secondary metabolites, known as cyanotoxins. The conditions that cause cyanobacteria to produce cyanotoxins are not well understood, but increased production has been observed at certain times during the year, particularly during the late summer.

What is microcystin?
Microcystin is a toxin that is released when the cyanobacterial organism dies or when one of its cell walls is destroyed. According to the U.S. EPA, there are over 80 different known variations of microcystin, but the most common is microcystin-LR.

Are these substances harmful to health?
Yes. Exposure to cyanotoxins – in drinking water or from direct contact with the skin – may cause a wide range of health symptoms in humans. They include fever, headaches, muscle and joint pain, blisters, stomach cramps, diarrhea, vomiting, mouth ulcers, allergic reactions, liver inflammation and hemorrhage, acute pneumonia, acute dermatitis, kidney damage, and potential tumor growth promotion. (Source U.S. EPA)

Are these contaminants regulated by the EPA?
Not at this time. Microcystin-LR and two other cyanotoxins in drinking water are being monitored by the EPA for potential future regulation.

How are these contaminants addressed?
In its fact sheet on cyanobacteria and cyanotoxins, the EPA recommends the use of microfiltration and ultrafiltration for the removal of intact cyanobacterial cells, and activated carbon, membrane filtration, nanofiltration or reverse osmosis, for the removal of extracellular toxins. However, WQA cannot verify this recommendation because we have never tested or certified a drinking water treatment device for the removal of cyanotoxins or cyanobacterial cells.

What can I do if cyanotoxins have been detected in my tap water?
If you have a water treatment system in your home, consult the product’s manufacturer or dealer to determine if the treated water is safe to drink, and also inquire about the need and method for disinfection and filter/membrane replacement.

Bottled water is always a safe alternative to tap water during contamination outbreaks affecting public water supplies. Please visit our provider directory to locate a bottled water supplier in your area. Please also consult a qualified water treatment professional for recommendations on how you can protect your household from the effects of possible future contamination outbreaks.

Where can I turn for more information?
For additional details on cyanobacteria and cyanotoxins, visit the EPA’s website.