[env-trinity] FW: Federal,
Tribal and State Authorities Advise Caution on
Dangerous Klamath River Algae
jallen at trinitycounty.org
Mon Oct 3 09:43:05 PDT 2005
Federal, Tribal and State Authorities Advise Caution on Dangerous Klamath
Author: North Coast Regional Water Board
Published on September 30, 2005, 16:48
In response to the emergence of dangerous algal blooms in the Klamath River
in California, the Karuk Tribe, the North Coast Regional Water Board and
the U.S. Environmental Protection Agency are joining other local, state and
federal agencies in warning residents and recreational users of the river
to use caution when near such blooms.
"This algae produces toxins that pose a significant potential public health
concern. We advise people to avoid all direct contact with Klamath River
water while the bloom is occurring." said Alexis Strauss, Water Division
director of the EPA's regional office in San Francisco.
Water samples taken over the past two months from Copco and Iron Gate
Reservoirs - located on the Klamath near the Oregon border - have revealed
high levels of the toxic blue-green alga Microcystis aeruginosa. Blooms of
Microcystis aeruginosa, which often occur between June and September, can
look like green, blue-green, white or brown foam, scum or mats floating on
the water. They have been found as far as 125 miles downstream of the
The Klamath River is rich in nutrients that support the growth of the
blue-green algae. Warm and calm surface water created by Iron Gate and
Copco Reservoirs provide an ideal environment for the growth of large algal
blooms. The extent of the blooms, and their toxicity, were not known until
studies were conducted this year by the Karuk Tribe.
"In August, we found levels of Microcystis aeruginosa as high as 46.8
million cells/ml along the shoreline and 8.9 millions cells/ml on the open
water. These levels exceed the World Health Organization (WHO) standard for
recreational use by 468 and 89 times, respectively," explained Susan Corum,
the Water Resources Coordinator for the Karuk Tribe's Department of Natural
Resources. "Microcystin toxin produced by the blooms in these locations was
1571.7 and 436.9 ìg/L; exceeding the WHO Tolerable Daily Intake level by
217 and 60.3 times respectively. These levels are among the highest
recorded in the United States."
According to California's Office of Environmental Health Hazard Assessment
(OEHHA), the U.S. EPA, the Karuk Tribe and Water Board, the Microcystis
aeruginosa and resulting microcystin toxin pose a significant potential
health threat to humans and animals exposed through direct ingestion of
contaminated water or incidental ingestion during recreational water
activities and bathing.
"The public needs to take the microcystin toxin in this algae seriously,"
said Catherine Kuhlman, Executive Officer of the North Coast Water Board.
"The levels of algae and associated toxins measured in parts of the river
are high enough to pose health risks to anyone drinking or bathing in the
water, particularly children and animals."
Studies of the possible health effects of exposure to Microcystis
aeruginosa and its microcystin toxin in the Klamath's waters range from
mild, non-life threatening skin conditions to permanent organ impairment
and death depending upon exposure time and intensity.
Symptoms could include mild to severe eye irritation, allergic skin rash,
mouth ulcers, fever, cold and flu-like symptoms, vomiting, diarrhea, kidney
damage, liver damage or complete failure, and death.
Children and animals are at the greatest risk of adverse effects, due to
their smaller body size and higher water ingestion rates.
As pets and other domestic animals could drink contaminated water, pets and
livestock should be kept away from the water.
There are three main ways to be exposed to Microcystis aeruginosa and
subsequent microcystin toxins in contaminated waters:
* direct contact to exposed skin or to the highly sensitive membranes of
the ear, eye, nose and throat;
* accidental or intentional swallowing; and;
* inhalation of contaminated water aerosols.
A full-grown adult ingesting 3.4 ounces of contaminated water in a given
day would be exposed to levels 28 times greater than the accepted World
Health Organization's Tolerable Daily Intake value. This calculation is
based on a single one-hour "swimming event" per day. More swimming events
or activities of longer duration could result in greater exposure.
For an average-size child who is 3-years-old, ingesting slightly more than
a measuring cup of contaminated water in any one "swimming event" would be
the equivalent of 278 times the accepted WHO Tolerable Daily Intake value.
As with adults, more swimming events or activities of longer duration could
result in greater exposure.
Local, state, tribal and federal health and environmental agencies
recommend that people not drink or cook with contaminated waters. You
should avoid or minimize contact with contaminated waters. It is best of
stay out of the water near algal blooms and to keep pets away. If you do
come in contact with the water, wash thoroughly with clean water. Avoid
eating fish caught during an algal bloom. If you do, fishermen should clean
the fish with fresh water and dispose of the innards away from the river or
where animals could eat them; Avoid irrigation with contaminated water;
Report dead or distressed wildlife along the shoreline to local, state or
For more information, visit: The 1999 World Health Organization, Toxic
Cyanobacteria in Water: A guide to their public health consequences,
monitoring and management at:
World Health Organization Guidelines for Drinking Water Quality, 3rd
Edition at: www.who.int/water_sanitation_health/dwq/gdwq3/en/index.html
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