Biologists, chemists and ecologists are in their third day of meetings at the University of Windsor. They’re focusing on the river that lies between that city and Detroit. They’ve also deliberated on Lake Erie. These waters are more polluted because they’ve been the wash basin for industry and farming. But all the Great Lakes have some of the same problems. Michigan Now’s Chris McCarus spoke with Dr. Russell Kreis. EPA station chief of the EPA on Grosse Isle. Kreis describes the worst contaminants in the lakes.
“Well I think if we put it in the perspective of fish that in human health and ecological health, pcb’s, mercury, dioxin and there are some other contaminants that are biocumulative are still driving the fish consumption advisories in the Great Lakes. They have been for many years, pcb’s are one of the first known as well as DDT. In the case of pcb’s they were banned in 1978. It’s gonna take about 100 years for those to disipate and be cleaned out of the lakes.
“A lot of this is being done by the Great Lakes Legacy Act. The dredging of the materials out of the rivers and tributaries etc. I think that in some cases we’re making progress. Maybe 50% or 80% reductions in fish concentrations. As it relates to Lake Erie, we’re still above the guidelines for fish consumption. But we’re making progress.”
“This nasty stuff,” McCarus said. “What is that stuff from again?”
“PCB’s were used in manufacturing processes,” Dr. Kreis said. “transformers and capacitors to disseminate heat on these kinds of instruments.”
“So the thing would be thirty to forty feet in the air attached to a power pole?” McCarus asked.
“It could be,” said Kreis. “These are some of the smaller units. They were used on much larger transformers and capacitors. A lot of that material was made. We’re talking about millions and millions of pounds. The production has been banned and we continue to make progress.”
McCarus asked “What would happen to the material it was being used? How did it get into the water and the fish?”
“Some of these leak through time,” said Kreis. “At one point we didn’t know the effects of these. They were thrown into waterways, down sewer systems. Just discarded through discharge. The ban has made it so they are not in use. But they’re still cycling in the water, the air and the sediment. But we’ve seen big progress in remediating those. In some cases where we do have these large sources they’re incinerated and made inert. So we continue to make progress on that front as well.”
“Is that the most nagging one where it seems like it was identified so long ago and yet its still so prevalent?” McCarus asked.
“Well this joins other things like DDT and dieldrin. The pcb’s do. But one of our nagging problems right now is mercury. There has been a lot of action with mercury. It’s also a bio-cumulative compound that gets into the fish and of course we eat the fish just like the pcb’s and other substances. Mercury is a natural element. But we also use it in many ways in life. So we’re making progress. Not as much as we want. But it still seems to be a high priority item. The mercury. “
A big source of mercury is coal fired power plants. The war against them began a few years ago in Michigan. PCB’s cause cancer and birth defects. The international treaty on Persistent Organic Pollutants, drafted by 122 nations in Johannesburg in December 2000, targeted PCBs as one of the `dirty dozeń chemicals to be phased out worldwide. However, this will take decades more of clean-up.