Prevention & Control | Harmful Algal Blooms | CDC

Prevention & Control | Harmful Algal Blooms | CDC

Prevention & Control

How to Reduce Exposures and Prevent Illness

Permanent HAB health advisory sign in Oregon. Credit: Photo courtesy of Oregon Public Health.

It is not possible to know if an algal bloom is harmful just by looking at it. Additionally, toxins can be present even when an algal bloom is not visible.

Protect yourself and your pets from harmful algal blooms (HABs):

• Avoid entering or playing in bodies of water that:
  • smell bad
  • look discolored
  • have foam, scum, or algal mats on the surface
  • contain or are near dead fish or other dead animals (for example, do not enter a body of water if dead fish have washed up on its shore or beach)
• Follow local or state guidance if you are notified that your tap water contains algal toxins. Boiling water does not remove algal toxins and can increase the amount of toxin in the water. Be aware of advisories and health risks related to consuming contaminated fish and shellfish. For more information, see the Environmental Protection Agency's (EPA) Choose Fish and Shellfish Wisely web pages.

Health Promotion Materials expanded

• See the Cyanobacterial Harmful Algal Bloom (HAB) Toolkit for materials to help the public recognize HABs and their health risks.
• See the Health Promotion Materials page for materials to help the public recognize HABs and their health risks.
• See the Drinking Water Advisory Communication Toolkit for information on communicating about water advisories.

Preventing Freshwater Exposures collapsed

Preventing Marine (Salt) Water Exposures collapsed

Preventing HABs collapsed

What should I do if I have been exposed? collapsed

What should I do if my pet has been exposed? collapsed

Reporting an Illness collapsed

State Resources