Scientist: Chinook in Sound have higher PCB levels
TACOMA – A state Department of Fish and Wildlife scientist has found that concentrations of banned toxic chemicals are substantially higher in Puget Sound chinook salmon than in chinook from other areas.
State health officials say there is no immediate cause for alarm but acknowledge they may revise fish consumption warnings in a few months.
Fish and Wildlife scientist Sandie O’Neill, who has studied PCBs (polychlorinated biphenyls) in salmon since 1992, recently found that concentrations in Puget Sound chinook are three times higher than what others have measured in chinook salmon from Alaska, British Columbia, Oregon, coastal Washington and the Columbia River.
O’Neill measured average PCB concentrations of 53 parts per billion in Puget Sound chinook. That’s like a spoonful of poison in a tank car full of water, but scientists believe the toxicity of the compound makes it notable.
O’Neill presented preliminary data to the state Fish and Wildlife Commission last October and plans to unveil more comprehensive research at the 2005 Puget Sound Georgia Basin Research Conference next week in Seattle.
Rob Duff, environmental health director for the state Health Department, said, “I don’t think the data is clear enough yet.”
Current Health Department advisories warn about contaminated fish or shellfish in several tainted locations around Puget Sound.
Duff suggested that that advice, which doesn’t mention salmon, is complicated and may not be sufficient.
Health Department researchers have set out to conduct their own tests on store-bought fish to analyze concentrations of PCBs, mercury and flame retardants, or PBDEs (polybrominated diphenyl ethers), which have been used in U.S. plastics for decades.
The state’s sampling list includes chinook salmon, catfish, pollock, red snapper, halibut, cod and flounder. After that analysis, in about three months, Duff said state health officials could revise statewide fish consumption recommendations.
PCBs are chemical compounds once used as coolants and lubricants in electrical equipment.
They were found in everything from lighting fixtures to hydraulic oils before a late-1970s ban in the United States.
Classified as a probable human carcinogen, PCBs build up in the food chain and can cause developmental and behavioral problems in children.
PCBs are found in meat and dairy products, but some health experts believe humans are most at risk from eating contaminated fish.