The U.S. Environmental Protection Agency has identified cyanotoxins as a contaminants for possible future regulatory action. Depending on the type of cyanotoxin and the amount of exposure, health impacts from cyanotoxins in drinking water may include gastroenteritis and damage to the liver and kidneys. Swimming or recreating in waters with harmful algal blooms may lead to allergic reactions, including irritated eyes, ears and throat, gastrointestinal distress, and rashes and skin lesions. According to EPA, children under six may be at higher risk than the general population from at least two cyanotoxins, microcystins
. EPA also advises that certain populations may be more susceptible than the general population to the health effects of these cyanotoxins, including nursing mothers and pregnant women, the elderly, and immune-compromised individuals or those receiving dialysis treatment.