Federal, state and tribal authorities advise caution
on dangerous Klamath River algae
For Immediate Release: September 30, 2005
Contact: Mark Merchant, U.S. EPA, (415) 947-4297; or William L. Rukeyser,
California State Water Resources Control Board, (916) 341-7365
Press Office Main Line: (415) 947-8700
SAN FRANCISCO – 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
reservoirs.
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 μg/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 tribal
authorities.
For more information, visit: The 1999 World Health Organization, Toxic
Cyanobacteria in Water: A guide to their public health consequences,
monitoring and management at:
http://www.who.int/water_sanitation_health/resourcesquality/toxicyanbact/en/
and,
World Health Organization Guidelines for Drinking Water Quality, 3rd Edition
at:
http://www.who.int/water_sanitation_health/dwq/gdwq3/en/index.html
Originally published at:
http://yosemite.epa.gov/r9/r9press.nsf/7f3f954af9cce39b882563fd0063a09c/c6bcacb2289059b68825708f006787cc!OpenDocument
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