Ann Arbor Times

Rich Welsh, director of ASTi Environmental, stopped by the Michigan Business Beat podcast and explained how the Michigan PFAS (polyfluoroalkyl substances) standards have dropped. 

Welsh, who is also a board-certified toxicologist, spoke in layman's terms and broke down the decrease in numbers. 

“When you want to figure out how toxic something is, like PFAS, you usually dose animals, like rats and mice, and then they look to see the effects, like cancer or birth defects, things like that... Generally, where you start to see some toxic effects with PFAS is around what they call a milligram of PFAS for a kilogram of body weight...That's about the same as for most of the other chemicals out there.”

He added that PFAS has been replaced with four carbons in the structure instead of eight. He noted that the eight-carbon PFAS typically lasts longer in individuals compared to the four-carbon, meaning they don’t accumulate as much. The replacement PFAS are calculated differently, in parts per trillion now, rather than the previous parts per million or parts per billion.

He went on to explain the options Michigan has moving forward. 

“They’re somewhat limited. The U.S. EPA... about a year or two ago, produced a drinking water health advisory for PFAS at 70 parts per trillion, which is, compared to other chemicals, really low. It was meant to be very health-protective. Michigan... and a few other states have made the decision that they think it’s not strict enough, so they’re even going lower... We don’t even get to use the U.S. EPA drinking water health advisory of 70 parts per trillion. We’re more using what are now the new Michigan drinking water standards, or MCLs that they’re producing that are right around 6 or 7 parts per trillion, so it’s gone the other way, much more stringent.”

He continued, saying that he and other scientists were tapped to review the drinking water standards and discovered that a recent study showed that PFAS could be used to treat cancer. Welsh and his fellow researchers used that data to determine that PFAS can last in the human body for months, rather than years, which ultimately changes PFAS calculations, making them much higher.

As for how this will impact businesses and municipalities, Welsh said, “Right now, PFAS are in many everyday items that we consumers use. It’s the reason your pizza box doesn’t get saturated with oil. It’s in cosmetics, it’s in dental floss, we use PFAS a lot... And one of the bigger uses is the firefighting foams... Either people are using PFAS in their manufacturing, like Wolverine for their boots, or they’ve been practicing firefighting somewhere with foam, they have the potential to have released it then into the environment, and the PFAS is readily soluble in water… So the cost to both go out and look for these chemicals and sample for them and test for them, and the cost to clean them up, is relatively more than what we’re used to with other chemical contaminants."