by Debbie Neustadt, originally posted on August 14,  2016

In Iowa it is widely accepted that the cause of nitrates in drinking water and rivers is fertilizer. Canoeists are beginning to avoid the Raccoon River because of nitrates [Iowa couple hangs up canoe over fear of nitrates in water, Aug. 7].

Now there is another health concern: microcystin, which comes from cyanobacteria. They pose a risk to human health through contact when swimming, boating or tubing, the ingestion of contaminated drinking water, or the consumption of contaminated fish or shellfish. Human illnesses following direct contact include symptoms of allergic rhinitis, conjunctivitis or dermatitis. Cases of the liver being affected have been documented in the United States and Australia.

In China, the incidence of liver or colorectal cancer was related to consumption of water that originated from sources contaminated with microcystin. Ohio has been concerned about microcystin contamination in drinking water derived from Lake Erie, especially exposure for children. In 2015 the National Parks Service in Nevada requested assistance in addressing the public health effects associated with a cyanobacteria in Lake Mead. This year, counties in southern Florida have had cynobacteria blooms and the governor has declared a state of emergency. We are not there yet.