What is Microcystin? Blue-Green Algae Toxin Taints Toledo, Ohio, Water Supply

Ohio Gov. John Kasich has declared a state of emergency in Toledo after a water treatment plant tested positive for microcystin, a toxin that can cause liver and kidney damage. The microcystin toxin is a product of cyanobacteria, a typically harmless form of blue-green algae, which has reportedly been in abundance in nearby Lake Erie.

The Los Angeles Times reported two water samples from the plant tested positive for microcystin, which was likely the result of an algae abundance in Lake Erie, the water source for the greater Toledo area.

Iowa’s Department of Public Health says algae blooms form when cyanobacteria multiply quickly during warmer, calm weather in bodies of water with high phosphorus and nitrogen levels. Such blooms, which often appear during late summer or early fall, can appear as green, red, orange or brown grass-like clumps but do not always produce byproducts harmful to animals or people.

However, the U.S. Environmental Protection Agency says the microcystins found in Toledo’s Collins Water Treatment Plant are the most concerning toxin from cyanobacteria blooms, known for primarily attacking the liver if ingested in large amounts. Other symptoms of ingestion can include diarrhea, nausea and dizziness. They are also known to irritate skin, eye and throat.

Though the water supply in the city has not been shut off, local alerts advised residents not to consume water, adding that boiling water does not rid water supplies of toxins, and in fact exacerbates toxicity. Water sources will need to be tested again to be certain microcystin toxins have been cleared as they can be present in supplies even if algal blooms are no longer present.

Symptoms can take anywhere from hours to days to appear in people or animals but will normally show up within a week after initial exposure. While there is no specific treatment for microcystin poisoning, supportive treatment for individual symptoms can be given.