If you’ve ever cooked with a non-stick pan or worn a waterproof jacket, you’ve probably benefited from a group of chemicals known as PFAS (or per- and poly-fluoroalkyl substances). PFAS are resistant to fire, water, oil, and many harsh chemicals. Their indestructibility makes them a popular additive in consumer products such as upholstered furniture, carpet, and food packaging; but it also means the chemicals linger indefinitely once they make their way into the environment.
Scientists have detected PFAS in Minnesota waters throughout the state, and most humans have PFAS in their bloodstream. The MPCA is working diligently to clean up the chemicals, as some are suspected to cause health problems in humans, including higher cholesterol, reduced immune response, and increased instances of thyroid disease and certain cancers.
So far, responding to the contamination has not been a simple task. “The chemistry related to PFAS is incredibly unique and complicated,” says Sophie Greene, the agency’s PFAS Coordinator.
The chemicals are not confined to a single environmental media, like water or air. They pass readily through these barriers, from industrial air emissions into surface water or from wastewater into agricultural soil. In landfills, for instance, PFAS can pass from discarded packaging that contains the chemicals into water percolating through the waste. University of Minnesota MnDRIVE researchers are developing a technology to trap PFAS in landfills, but at this point, the chemicals eventually escape to nearby soil and groundwater. All of this complicates the MPCA’s response, which has separate departments for each environmental media. Part of Greene’s role as PFAS Coordinator is to ensure interdepartmental staff, like air monitoring scientists and water quality scientists, reach compatible remediation strategies.
PFAS chemistry includes more than 5,000 registered compounds. Each requires its own toxicological assessment to determine acceptable levels of exposure, but scientists have completed only a select few. “This puts us in a really difficult position as a regulating agency,” says Greene, explaining that if the minimum level at which a chemical can affect human health isn’t specified, it’s difficult to set limits on the chemical’s use.
Even for the compounds with well-established exposure limits, identifying the source of contamination isn’t straightforward. For example, wastewater treatment facilities release PFAS when they apply the solid waste produced from water treatment as a soil fertilizer. The wastewater facilities aren’t creating the PFAS in the solid waste, however; they just accept industrial and human waste containing the chemicals. Greene is working with a team of PFAS experts to establish fair strategies for reducing exposure in a system without obvious sources. “The question is not should we control it.” says Greene, “The question is where it’s the most cost-effective, responsible, and fair way to control this class of compounds.”
PFAS won’t be an easy problem to solve, but Greene is hopeful based on what she’s seen in her first year with the agency. “The government here in Minnesota is working really hard to make sure that the exposure people have to PFAS-containing compounds is as limited as possible,” she says. For the next six months, she’ll focus on creating a PFAS action plan outlining high-priority opportunities for remediation. Her goal is to inform the public on which policies will provide the most bang for their buck in protecting our health and environment.
Written by Caroline Frischmon