Where It Comes From
Produced by bloom-forming cyanobacteria (e.g., Microcystis, Dolichospermum/Anabaena, Planktothrix) in warm, nutrient‑rich lakes and rivers [1][2].
How You Are Exposed
Swallowing contaminated tap or recreational water; inhaling spray while boating; eating fish from bloom areas (especially organs) [1][2][4].
Why It Matters
Causes nausea, vomiting, diarrhea, and liver injury; pets can die. Repeated exposure may raise risks of chronic liver disease; microcystin‑LR is a possible carcinogen [2][5].
Who Is at Risk
Young children, pregnant people, those with liver disease, people on dialysis, and pets/livestock; they can get sicker at lower doses [2][3].
How to Lower Your Exposure
Avoid discolored/scummy water and heed advisories; don’t boil contaminated water (concentrates toxin); use certified filters or safe sources; rinse fish fillets, discard guts; keep pets away [1][2][3].
References
- [1]CDC. About Cyanobacterial (Harmful Algal) Blooms. https://www.cdc.gov/harmful-algal-blooms/
- [2]WHO. Microcystin‑LR in Drinking-water: Background document for development of WHO Guidelines. 2020. https://www.who.int/publications
- [3]EPA. Recommended Human Health Recreational Ambient Water Quality Criteria/Swimming Advisories for Microcystins and Cylindrospermopsin. 2019. https://www.epa.gov/wqc
- [4]ATSDR. Toxicological Profile for Cyanobacterial Toxins (Draft for Public Comment). 2022. https://www.atsdr.cdc.gov/toxprofiles/cyanobacterial_toxins
- [5]IARC. Monographs Volume 94: Ingested Nitrate and Nitrite, and Cyanobacterial Peptide Toxins. 2010. https://publications.iarc.fr/119