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Why the proposed PolyMet sulfide mine needs a formal health risk assessment

A discussion with Kathleen Schuler, a member of the Minnesota Public Health Association’s Policy and Advocacy Committee, who is calling for a formal health risk assessment of the proposed PolyMet mine.

Minnesota DNR
The plan for the NorthMet mine site at year 20, when extraction operations are projected to end. Sulfides in waste rock at the mine site will need to be contained and treated for an additional 200 years. Click for larger version.

A growing number of Minnesota’s health professionals and scientists are publicly expressing their concern about the potential health impacts of the proposed PolyMet sulfide mine near Hoyt Lakes.

Earlier this week, several health-related groups, including the Minnesota Public Health Association and the Minnesota Medical Association, joined others in asking Gov. Mark Dayton to require the Minnesota Department of Health to conduct a formal health risk assessment of the controversial mine project.

The health experts are particularly concerned about how the project will increase mercury in fish, contaminate drinking water with toxins such as lead and arsenic, and release pollutants — including nickel dust and asbestos-like mineral fibers — into the air.

One of the experts who signed the latest letter to the governor is Kathleen Schuler, a member of the Minnesota Public Health Association’s Policy and Advocacy Committee and director of the Healthy Kids and Families program at Conservation Minnesota. Earlier this week, MinnPost spoke with Schuler about her health concerns related to the PolyMet mine project. An edited version of that interview follows.

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MinnPost: You’ve called the proposed PolyMet mine project a public health issue. Why?

Kathleen Schuler: There are two aspects to it — the increased effects on the general population and also the increased effects on workers who take part in this industry. As far as the general population is concerned, there’s increased potential for mercury pollution, increased potential for water pollution and an increased risk of air pollution.

MP: What is the concern with mercury?

KS: There’s a potential for mercury methylation. When mercury gets into the environment and is acted on by bacteria it can turn into methylmercury, which is a form of mercury that can build up in the food chain. Ultimately, it ends up in the fish, and we eat the fish.

The potential for methylation has not been fully assessed in [the PolyMet mine] project. There are already high levels [of methylmercury] in the St. Louis River and other water bodies in northern Minnesota. And there are already high levels of mercury in fish in northern Minnesota. [The Minnesota Department of Health] does several bio-monitoring projects, and one in particular looked at mercury in newborns. They found that one in 10 infants born in the Lake Superior region has blood levels of mercury that are higher than the [Environmental Protection Agency] safety standard.

MP: Should people in other regions of the state be concerned? 

Kathleen Schuler
Conservation Minnesota
Kathleen Schuler

KS: Yes. Mercury is a global pollutant, so it can be deposited thousands of miles from where it’s emitted. It’s more of a concern in northern Minnesota because we have higher exposure among infants in that area of the state, [but] it can affect everyone.

MP:  What is the current source of the mercury that is getting into those infants’ bodies?

KS:  The main source is fish consumption.

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MP:  And where is the mercury coming from that’s getting into the fish?

KS: The biggest source of mercury in our environment is coal-burning [power plants and other facilities]. With PolyMet, there will be an increase in fossil fuel use that would not only increase mercury but would increase air pollution. There’s a link between air pollution and cardiovascular disease and respiratory problems. And then there’s the possibility that arsenic, magnesium and lead could get into the water and pollute wells.

MP: What is the health concern regarding those three metals?

KS: They’re neurotoxins, and arsenic is linked to cancer. People in the region will be exposed [to these and other toxins] both through air, through water and through fish consumption, so there’s multiple effects that need to be examined. 

MP: We have had taconite mining in northern Minnesota. How do sulfide mines differ from taconite mines in terms of releasing potentially toxic chemicals?

KS: That’s another area that hasn’t been assessed. We know that there’s a risk of mesothelioma from asbestos-like fibers, and that was definitely a concern with taconite mining. There are going to be asbestos-like fibers generated through sulfide mining, so that would put workers at risk for mesothelioma — or could. It needs to be looked at. There’s also the potential for exposure to particulates and nickel dust. Those are all potential risks for workers working at the plant. And who knows if those pollutants are going to get out into the broader environment and expose the community.

MP: You’re particularly concerned about the risks that these chemicals might pose to infants and children.

KS: Yes, especially with mercury and water pollutants. The most at-risk is a fetus, so we’re concerned about pregnant women. In Minnesota we have fish-consumption advisories. Pretty much every water body has mercury, and pretty much every type of fish has some level of mercury in it. The health department gives pregnant women advice on which fish to avoid — if you’re going to eat walleye, for example, don’t eat very much. The reason is the fetus’ brain is developing, and because mercury is a potent neurotoxin, it can definitely affect brain development. It could turn up in subtle ways as [attention deficit hyperactivity disorder] or reduced IQ. There’s no way of knowing what the effects are going to be. That’s why it’s more protective of the public health to avoid mercury exposure at all costs, if you can.

MP: What would you say to people who say we already have these contaminants in the environment — for example, we’re already warning pregnant women about eating fish — so the propose PolyMet mine won’t really change the health risk that much?

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KS: That’s just it. We need an assessment to find out if it’s going to be worse, and, if so, how much, and then is it worth the cost to our health to go forward with the project?  It’s not just the economic costs or the economic benefits. We also have to look at the environmental costs and the public health costs. That’s why doing a health risk assessment and a health impact assessment are necessary for a big project like this.

MP: Do you find it difficult to get across the message that environmental toxins can be dangerous? After all, their effects on health may take years to develop.

KS: My work involves chemicals in consumer products. You don’t want people to panic and feel as if they can’t buy anything because it might have a toxic chemical in it. But that’s why people need good information. The effects [of these chemicals] are so subtle, especially when some of them can act and affect your health at a very low level. Any amount of lead — and mercury as well — can affect the brain. You definitely want to avoid any exposure at all. But it’s hard because you can’t see it. It’s hard to picture how a tiny amount of chemical is actually going to affect your child’s development. But if we look at the science, the science is definitely there. 

That’s why we need a health impact assessment before we go forward with [the PolyMet mine project]. … [Sulfide mining] is a huge new industry in Minnesota. We don’t know what the public health effects are going to be. We can guess what they’re going to be, but we’d be only guessing, because we haven’t really assessed them. … I think we’ll be sorry if we don’t do that assessment.