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Department of Ecology News Release - June 3, 2004
04-104
OLYMPIA - Mercury levels at the bottom of Lake Whatcom are declining, according to research by the state Department of Ecology (Ecology).
Sediment cores going back more than 150 years indicate that mercury levels in the lake peaked in early to mid-1990s and appear to be declining. Current mercury levels in surface sediments are approximately 25 percent less than peak levels found in the core samples.
Over all, mercury in water from the tributaries and in surface sediments from the lake is consistent with levels seen in other areas of Western Washington.
"We're encouraged to learn that mercury levels in sediments are falling," said Dick Grout, who manages Ecology's field office in Bellingham. "From a public-health standpoint, the mercury in the sediments is not a serious threat at this time, and we can keep it that way by not feeding the bacteria that draw the mercury into the food chain."
The study notes that controlling common pollutants that contribute to low-oxygen problems in the lake water could help slow the uptake of mercury into the lake's food chain. The pollutants trigger a biological process that lowers oxygen levels in the water and provides ideal conditions for producing methyl-mercury, which is the form of mercury that enters the food chain.
Ecology is developing a water cleanup plan to control these pollutants, which include fertilizers, detergents, septage and animal waste that enter the lake through stormwater runoff.
The research examined sediments at the bottom of Lake Whatcom and water entering the lake from several tributaries. Samples were collected in 2002 and 2003, in response to earlier findings of elevated levels of the toxic metal in certain species of Lake Whatcom fish.
The state and Whatcom County health departments issued a public health advisory in 2000 warning women of childbearing age and children under age six to not eat smallmouth bass and to limit consumption of yellow perch to one meal a week. In 2003, the state Department of Health issued a statewide advisory warning people to limit their consumption of both smallmouth and large-mouth bass from all lakes in Washington.
Water from Lake Whatcom that is processed at Bellingham's water treatment plant falls within standards considered safe for drinking, based on testing conducted by the city.
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Contact: Larry Altose, public information officer, 425-649-7009; pager, 206-663-1785
Read the report on-line: http://www.ecy.wa.gov/biblio/0403019.html
Copyright © Washington State Department of Ecology. See http://www.ecy.wa.gov/copyright.html.
