Cleaning up PFAS

Per- and polyfluoroalkyl substances, known as PFAS or "forever chemicals," pose significant threats to human health and the environment. Used in products ranging from nonstick cookware to firefighting foams, these synthetic compounds are resistant to breakdown, persisting in the environment for years. PFAS compounds are characterized by strong carbon-fluorine bonds, making them challenging for natural processes to degrade.

The ubiquity of PFAS is alarming. They contaminate water and soil, and evidence suggests they have infiltrated human bodies, even in remote locations like Antarctica. A 2022 study revealed that 89% of the US population had PFAS levels exceeding 2 nanograms per milliliter of blood plasma, a concentration associated with potential health risks, while 9% exceeded the more concerning threshold of 20 nanograms per milliliter.

Unlike any other persistent pollutant, PFAS compounds are continuously evolving, with over 12,000 new variations continually being developed and used. However, due to the complexity and sheer number of these compounds, most research efforts only focus on a select few. Efforts to clean up PFAS-contaminated soil are in their early stages, but a solution exists to prevent further contamination by removing PFAS from water systems. Two primary methods exist: trapping or destroying the chemicals.

Trapping PFAS involves filtering out the chemicals from water supplies. Point-of-use solutions, such as kitchen sink filters, can employ reverse osmosis, a process that pushes water through highly selective membranes. However, trapping results in a potentially problematic byproduct—a brine saturated with PFAS. Destroying PFAS is a more comprehensive approach, but it presents its own set of challenges.

One promising technique is electrochemical degradation, which uses electrical energy to break the chemical bonds holding PFAS together. This method has demonstrated over 90% destruction efficiency in laboratory tests and has already been commercialized by the engineering firm AECOM.

Addressing the PFAS crisis also involves policy changes. Alternatives to PFAS exist; the challenge is in incentivizing their adoption. While significant progress has been made, with the EPA's PFOA Stewardship Program reducing PFOA releases by 95%, more action is needed. Recent legislation in states like Minnesota, Maine, and New Mexico demonstrates growing awareness and commitment to protecting citizens from PFAS exposure.

As scientists continue to refine PFAS removal and destruction technologies, we must also focus on preventing their release into the environment in the first place.