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Science advisor: In midst of uncertainty, new limit for PFAS chemicals errs on “side of caution”

Jan 10, 2018

Michigan has set new cleanup rules for chemicals that have contaminated drinking water sources all around the state. The chemicals in question are per-and polyfluoroalkyl substances (PFAS).

They were used in firefighting foam and in a wide range of products, from fast-food paper wrappers to textiles and carpeting, pesticides, printing inks, and more. They have since been linked to some cancers and other health problems.

David Savitz, leader of the Scientific Advisory Committee to the Michigan PFAS Action Response Team, joined Stateside today to explain the new rules.

Listen to the full conversation above, or read highlights below.

On the new limit for PFAS in water

The Department of Environmental Quality yesterday set Michigan’s limit for PFAS in drinking water sources at 70 parts per trillion.

That number comes from the Environmental Protection Agency, Savitz said. It’s “an advisory or a guideline” put out by the agency.

Formally setting this threshold, Savitz said, gives Michigan the ability to enforce that standard.

On whether this new criteria is stringent enough to keep people safe

Savitz said researchers don’t yet have a complete understanding of potential health effects of PFAS.

“And in the face of that uncertainty, the intent was to err on the side of caution,” he said. “So based on what we know today, it is indeed a restrictive and cautious level to work with.”

On why understanding of PFAS health effects is limited

Savitz said PFAS chemicals have been a known concern for only about a decade, or even less.

“Now, that may sound like a long time, but to take a very complex class of chemicals – we’re not talking about one chemical, we’re talking about dozens or potentially thousands that fall into this class – and go from essentially no knowledge, maybe, say, 10 years ago, to having a handle on them is really quite challenging,” he said.

Still, he thinks research is actively progressing.

“With advances in the research, we’ll be in a much better position to establish, you know, evidence-based regulatory limits,” he said. “Right now, this is set based on the little that we know combined with judgment and caution, and that’s appropriate, I think. But, as the evidence changes, it’s quite possible that the recommended levels would change as well.”

On how the new standard in Michigan compares with other states

Savitz said the ways states have “interpreted and extrapolated” from the EPA recommendation varies.

“Many of them have adopted it,” he said. “Some of them have not adopted any standard. Some of them have made some choices about making it even lower. There are different philosophies behind it.”

“The evidence is what it is,” he said, “and then it’s a matter of how that is used and interpreted across different agencies.”

Hear the full conversation above.

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