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OHA News Release

Media contact:
Jonathan Modie
OHA Public Health 971-246-9139
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Health advisory issued July 9 for Willamette River’s Ross Island Lagoon

A health advisory is being issued today for the Willamette River at the Ross Island Lagoon, including the mouth where it enters the Holgate Slough. Ross Island is located about one river mile south of downtown Portland in Multnomah County.

Water monitoring has confirmed the presence of blue-green algae in the lagoon, and toxin analysis is being performed to confirm the presence or absence of toxins. Until toxin testing can be completed and data received, the Oregon Health Authority is issuing the advisory based on visible scum and the bright green layers of cells that are visible in the water column. Once toxin data are received, the advisory will be updated or lifted based on the results.

Oregon Public Health officials advise people to avoid swallowing or inhaling water droplets as a result of swimming or high-speed water activities such as water skiing and power boating, in areas where blooms are identified.

Drinking water directly from the river where a bloom is identified is especially dangerous since any toxins produced cannot be removed by boiling, filtering or treating the water with camping-style filters. People who may draw water directly out of this area for drinking or cooking are advised to use an alternative water source. No public drinking or potable water systems are affected.

Oregon health officials recommend that people who choose to eat fish from waters where algae blooms are present remove all fat, skin and organs before cooking, because toxins are more likely to collect in these tissues. Public health officials also advise people to not eat freshwater clams or mussels from any freshwater source affected by a bloom and that Oregon Department of Fish and Wildlife regulations do not allow the harvest of these shellfish from freshwater sources. Crayfish muscle can be eaten, but internal organs and liquid fat should be discarded.

Exposure to toxins can produce symptoms of numbness, tingling, and dizziness that can lead to difficulty breathing or heart problems, and require immediate medical attention. People who experience symptoms such as weakness, diarrhea, nausea, vomiting, cramps and fainting should also receive medical attention if they persist or worsen.

Contact with cells from a bloom can cause skin irritation and a rash in individuals with skin sensitivities or who develop rashes easily.

Children and pets are at increased risk for exposure because of their size and level of activity. People who bring their pets to areas where blooms are identified should take special precautions to keep them from drinking from or swimming in the water.

The public will be advised when the concern no longer exists.

People are encouraged to visit the river and enjoy activities such as fishing, camping, hiking, biking, picnicking, bird watching, and boating at low speeds, but should limit water activities that can expose them to ingestion or inhalation in those areas where a bloom is identified or an advisory is in place. The Willamette is a big river and blooms can develop in areas along its course where low flow and slow-moving water can be found. If you see areas where the water is foamy, scummy, thick like paint, pea-green, blue-green or brownish-red, follow the motto “When in doubt, stay out.”

For more information or to report a human or pet illness, contact the Oregon Health Authority at 971-673-0400.

OHA maintains an updated list of all health advisories on its website. To find out if an advisory has been issued or lifted for a specific water body, visit the Harmful Algae Blooms website at www.healthoregon.org/hab and select “algae bloom advisories,” or call the Oregon Public Health Division toll-free information line at 1-877-290-6767.

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