The noted scientist and book author Mel Visser (book plug at the bottom) sent me this, which looked like an ideal guest item about something I don't know enough about. Now I know a bit more. My pleasure to post it:
I do not see much about persistent organic pollutants (POPs,) a Great Lakes subject that deeply concerns me, on your blog.
On retiring in 1995, I searched for an answer to the residual PCBs in Lake Superior. When banned in 1978, concentrations rapidly decreased to 50% of their peak ... and stayed there. This is not what would be expected, there had to be a continuing source.
I could not find the answer through voluntary efforts with the EPA and by serving on the Science Advisory Board of Michigan's Great Lakes Protection Fund.
On hearing of a study finding that Inuit above the Arctic Circle had 8X more breast milk PCBs than women in southern Canada, my search headed north.
From two trips to the Canadian High Arctic and assimilation of research done under the Arctic Monitoring and Assessment Programme, a multi- nation study, the picture came together.
Continuing megaton global use of PCBs and "banned" pesticides keeps our Great Lakes contaminated and is devastating the Arctic environment.
The 8X PCB level was only 7% of the Inuit toxic load, with the majority coming from chlordane and toxaphene.Toxaphene was virtually banned in 1982.
By 1992, its concentration in Lake Michigan had gone down, but the levels in Lake Superior went up 50% and have stayed there. Lake Trout in Lake Superior have a toxaphene concentration 10X that required to classify them as hazardous waste.
This is also 10X the PCB toxicity in those same trout. Yet ... Michigan's Fish Consumption Advisories warn against consuming large trout because of their PCB content and remain silent about toxaphene.
Before condemning Michigan, check Wisconsin's advisories. Ontario, Michigan and other states dropped toxaphene from advisories sometime before 2004.
Why does Lake Superior attract toxaphene?
The POPs (persistant organic pollutants) circle the globe and concentrate at different latitudes according to their volatility.
Lindane, very volatile, was found at 40X the concentration in the Arctic Ocean as in oceans near its use points.
PCBs spread across the continental US and diminish to the north.
Toxaphene finds the cold mountain lakes, the northern Great Lakes and the Arctic to its liking. What is the EPA doing? Nothing.
At the International Joint Commission meeting in Chicago last week, a glowing progress report was presented ... Lake Superior's toxaphene was not mentioned.
According to the EPA, POPs will exit the lakes in another 10-30 years as they remove contaminated sediments and address virtual elimination.
Good Luck!
This head-in-the-sand approach of ignoring the biggest toxicity problem in the Great Lakes ... and lying through Fish Consumption Advisories published to protect us, will only serve to keep the hard work of truly achieving a global ban on agricultural use of POPs pesticides and industrial use of PCBs from starting.
The 2001 voluntary Stockholm Agreement has done nothing but stirred up a backlash on DDT and cleaned up storehouses in Africa … efforts that the Lake Superior trout will not feel.
My search and conclusions have been published as the book Cold, Clear, and Deadly. See my web site at http://www.coldclearanddeadly.com/ for more information.
Best wishes to you and our Great Lakes.
Mel Visser
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