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CDPH Urges Caution Related to Seasonal Blue-green Algae Blooms 

Date: 8/24/2016 
Number: 16-054 
Contact: Ali Bay - (916) 440-7259 

SACRAMENTO – California Department of Public Health (CDPH) Director and State Public Health Officer Dr. Karen Smith urges recreational water users to avoid close contact with water bodies containing blue-green algae. Since June of this year, blue-green algae blooms have been identified in more than two dozen freshwater reservoirs, lakes and streams statewide.

A list of current algal blooms is available online. The state recommends that people and pets avoid contact with affected bodies of water.

“Boaters and swimmers across the state should be aware of posted signs that indicate the presence of blue-green algae,” said Dr. Smith. “These blooms can produce toxins that pose a health risk if the affected water is touched or swallowed. Signs of blue-green algae poisoning include eye irritation, skin rashes, mouth ulcers, vomiting, diarrhea and cold and flu-like symptoms.”

Blue-green algae poisoning is most common and symptoms, including death, can be more severe in pets and livestock because they tend to drink the water from affected lakes and reservoirs. Children and adults can experience serious injury to the liver, kidney and nervous system if affected water is swallowed. Medical treatment should be sought immediately if a person, pet or livestock is suspected to have blue-green algae poisoning.

Blue-green algae, also called cyanobacteria, are microscopic bacteria that have been found in freshwater lakes, rivers and streams across the state this summer. The algal blooms can appear as blue-green, white or brown foam, scum or mats that typically float on the water’s surface and collect along shorelines and boat ramp areas. Blooms are caused by slow-moving warm water and high levels of nutrients in the water. They can move, grow or shrink depending on conditions.

Common water purification techniques, including camping filters, tablets and boiling, do not remove toxins from affected water.

The state recommends guidance for people who recreate at affected water bodies:

  • Take care that pets and livestock do not drink the water, swim through algae, scums or mats, or lick their fur after going in the water. Rinse pets in clean water to remove algae from fur.
  • Avoid wading, swimming, or jet or water skiing in water containing algae blooms, scums or mats.
  • Do not drink, cook or wash dishes with untreated surface water from these areas under any circumstances. Common water purification techniques, such as camping filters, tablets and boiling, do not remove toxins.
  • People should not eat mussels or other bivalves collected from these areas. Limit or avoid eating fish from these areas. If fish are consumed, remove the guts and liver, and rinse filets in clean drinking water.
  • Get medical treatment immediately if you think that you, your children, your pet or livestock might have been poisoned by blue-green algae toxins. Be sure to alert the medical professional to the possible contact with blue-green algae. Also, make sure to contact the local county public health department.

Additional Blue-Green Algae Resources:

State Water Resources Control Board: California CyanoHAB Network

California Office of Environmental Health Hazard Assessment: Information on Microcystin

U.S. Environmental Protection Agency: CyanoHAB website

US Environmental Protection Agency: Anatoxin-a report 
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