Mel Visser: Great Lakes won't be clean until global pesticides banned

[Demeter]

http://www.madison.com/tct/opinion/column/265436


Do you ever wonder why the "scientists" quoted by Mike Ivey never mention the most toxic substance in the Great Lakes?

I retired from a career in chemical and environmental engineering wondering why the long-banned PCBs remained at a constant level in Lake Superior. After a couple of years of volunteer work with the Environmental Protection Agency and the state of Michigan, I had learned nothing. A search that included two trips to the Canadian Arctic and assimilation of international research finally led to surprising findings, the realization of horrendous government actions, and answers.

Surprise findings: Toxaphene, the pesticide that replaced DDT when it was banned, is present at twice the PCB concentration in Lake Superior trout and gives them 10 times more toxicity. The levels of PCBs and toxaphene in Lake Superior are remaining fairly constant.

Toxaphene was virtually banned in the U.S. in 1982. If it is present in waste at the level of one-half part per million, the waste is classified as "hazardous waste." The U.S. EPA, the scientific body supplying data for fish eating advisories, recommends very little ingestion of toxaphene: . Prior to 2004, toxaphene was responsible for the majority of Lake Superior's fish consumption advisories.

Horrendous government action: In 2004, the health departments of Ontario and the states surrounding Lake Superior stopped including toxaphene in their fish eating advisories. We are no longer told to restrict our intake of fish that are contaminated at 10 times the level that would classify them as hazardous waste.

Answers: In the 1960s, agricultural technology requiring toxaphene, chlordane, Lindane, etc., was exported to developing countries to save them from starvation. These countries now feed a greatly expanded population and export food back to us. The "banned" pesticides that they still use circulate through the air to contaminate our air and waters.

In this global circulation, PCBs deposit across the continental U.S. and decrease to the north. Lindane races to the Arctic and is present in the Arctic Ocean at 40 times the concentration in temperate oceans. Toxaphene likes the northern Great Lakes, mountain lakes, Lake Laberge in the Yukon, and the Arctic, where Inuit women of child-bearing age ingest four times the tolerable daily intake of toxaphene from the small portion of their diet obtained from marine mammals.

Toxaphene, PCBs, chlordane and the other banned pesticides will not leave the Great Lakes until they are globally banned. Hiding the problem will not make it go away and spending the hoped-for $20 billion to clean up the lakes will do nothing for the most toxic chemicals currently in the lakes.

My quest for answers was published as "Cold, Clear, and Deadly: Unraveling a Toxic Legacy" by Michigan State University Press.

I hope the truth of what is in our lakes will prevail and our leaders will develop the courage to address rather than hide from problems.

Mel Visser of Portage, Mich., is a lifelong resident of the Great Lakes area