An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Climate Change Adaptation Resource Center (ARC-X)

Climate Adaptation – Recreational Water and Health

Chicago Navy PierAt Lake Michigan beaches, warning flags are raised when bacteria counts are high.EPA supports local and state efforts to protect and clean recreational waters, such as lakes and beaches, by supporting the monitoring and notification efforts of local water programs. Climate change may affect recreational waters as a result of an increase in the frequency and intensity of storms and warmer air temperatures.

More frequent storms and floods may cause more runoff of animal waste and other pollutants into recreational bodies. Overflows from sewage systems and treatment plants can also contaminate recreational water bodies.

Exposures to these contaminants can affect health by causing gastrointestinal distress, respiratory infections, and ear and skin infections.

More runoff of nutrients from land (e.g. agriculture, fertilized lawns) under some conditions can cause the growth of harmful algal blooms in recreational water bodies. Harmful algal blooms can produce extremely dangerous toxins that can sicken or kill people.

Toxins from algal blooms may contaminate seafood that may cause food-borne diseases if consumed.

People who are exposed to algal bloom toxins may experience adverse health effects, such as:

  • Nausea
  • Vomiting
  • Diarrhea
  • Bad taste in mouth
  • Acute hepatitis, jaundice
  • Blood in urine or dark urine
  • Malaise
  • Headache, fever
  • Loss of appetite
  • Progression of muscle twitches
  • For saxitoxin: high doses may lead to progressive muscle paralysis
  • Allergic dermatitis (including rash, itching, and blisters)
  • Eye infections
  • Inhaling aerosols contaminated with cyanobacteria or toxins may cause upper respiratory irritation (wheezing, coughing, chest tightness, and shortness of breath)

Explore More About Adaptation – Recreational Water and Health