Local view: North Shore mercury poisoned babies still live in a polluted world
In late 2011, the Minnesota Department of Health released a study on the levels of mercury in the blood of infants born in the Lake Superior watershed. The study showed that 10% of infants in the Minnesota part of the watershed had mercury levels above health limits. Nearly 120 babies on the Lake Superior shore faced an uncertain future due to a contaminant their mothers ingested and passed on to them.
Unlike many scientific studies that disappear from academic journals, this one triggered an immediate wave of concern as well as a remarkable follow-up program. The media were quick to pick up the story.
However, the Minnesota Department of Health doesn’t just do research. He takes action. Funded by a grant from the Great Lakes Restoration Initiative and in collaboration with health clinics in Grand Marais and Grand Portage, officials from the state health department launched the Fish are Important for Life project. superior health (FISH).
Women of childbearing age along the North Shore provided blood samples and shared the amount of fish they normally included in their diet. While walleye are higher in mercury, other local wild fish are lower in mercury, and participants learned how to choose the right fish to eat. Follow-up studies have shown that participants generally reduced the amount of mercury in their blood.
But reducing the level of mercury in your diet is not the same as reducing the level of mercury in the environment.
Unfortunately, the levels of mercury in the environment do not appear to be declining. The Saint-Louis River is the largest tributary of Lake Superior on the American side. It has been known for decades that the Saint-Louis River contains too much mercury. Anglers along the river are warned to limit their intake of river fish, primarily because of the mercury.
If you live in West Duluth or Morgan Park and would like to catch some crap to feed your family, be careful: the Minnesota Department of Health does not recommend more than one meal per month from St. Louis for children. children or children’s wives. – reproductive age, due to mercury contamination in fish tissue.
Mercury in the Saint-Louis River comes from several sources. Recent studies have shown that mercury from decades ago reappears from sediments at the bottom of the river and enters the food chain. Taconite and power plants in northeast Minnesota continue to emit mercury into the air, and it falls into the upper St. Louis River just downwind. Sulphate pollution from the same sources reacts with mercury and creates methylmercury, the form that fish (and babies) take. The proposed new mines could add more mercury and more sulphates.
But just because the sources of mercury in the river are complicated doesn’t mean there’s nothing we can do about it. The good news is that we have a way forward to address this issue. State agencies are mobilizing.
Through the Clean Water Act, governments are required to address water quality problems. This process begins with determining how much mercury is entering the river and where it is coming from. This process is known as the Total Maximum Daily Load study or the TMDL study.
Over the next few months, the Minnesota Pollution Control Agency will restart its long-awaited TMDL study of mercury in the St. Louis River. This could ultimately lead to long-awaited licensing restrictions on mercury emissions, as well as guidance on related environmental chemicals like sulfates. The Minnesota Environmental Partnership urges the MPCA to do this job properly and involve communities and local knowledge along the river.
The blood of infants told us what we suspected, that there is too much mercury in the St. Louis River. Mercury from local sources – from taconite factories to municipal wastewater treatment plants – needs to be reduced. And we should never add new sources of mercury to the watershed.
The babies in this original study are now 10 to 12 years old and are finishing primary school. Wouldn’t it be great to tell them now that they live in a cleaner world, that the mercury of Lake Superior and its tributaries has dropped, and that they can eat all the crap they can catch?
We are not there yet. Let’s tell them this: If we can do the St. Louis River Mercury TMDL properly, we’ll be on our way to getting there.
Andrew Slade of Duluth is the Great Lakes Program Director for the Minnesota Environmental Partnership (mepartnership.org), a nonprofit organization based in St. Paul.