Read the full article by Tarun Anumol (Water World)
“Per- and polyfluoroalkyl substances (PFAS) are some of the most far-reaching man-made chemicals in the world today, permeating our daily existence in everything from non-stick cookware to takeout containers.
Nothing about PFAS — from how they are made to their impermeable nature to how they need to be analyzed — is easy. The irony is unmistakable: we developed these chemicals to simplify our lives only to be haunted by their elusive and difficult nature decades later, and it’s a serious problem. A few things are known for certain — how the compound works, what its limitations are, and that PFAS contamination is an environmental and growing health issue. What is less clear is how to address this issue and manage it in a way that leaves the environment unmarked.
In this Q&A round table, scientists from around the globe share their perspectives on current research and technological advances being used to address these forever chemicals.
James Dodds is post-doctoral student at North Carolina State University. Erin Baker is an associate professor at North Carolina State University. Together, Dodds and Baker’s work focuses on utilizing new analytical techniques such as ion mobility spectrometry (IMS) for detecting and characterizing PFAS isomers and newly observed PFAS compounds. While most PFAS studies are currently performed using traditional LC-MS approaches for known compounds, IMS separations provide a novel way of analyzing and identifying the many new features occurring in untargeted PFAS sample analyses.
Detlef Knappe is a professor at North Carolina State University who advises students and postdoctoral researchers focused on a wide range of topics, including the development of targeted and non-targeted analytical methods for PFAS in water, biological samples, and soil; the development of tailored sorbents for the selective removal of PFAS from water; and the assessment of readily implementable water treatment technologies.
Bradley Clarke is a senior lecturer in analytical chemistry and environmental science at the University of Melbourne, Australia. His work focuses on the environmental sources, fate, and impact of PFAS on public health and the environment.
Christian Zwiener is a professor of environmental and analytical chemistry at Eberhard Karls Universität Tübingen, Germany, interested in PFAS used for paper and cardboard impregnation and their transformation products. Currently, his focus is on fluorotelomer-based phosphate diesters (diPAPs) and sulfonamide ethanol-based phosphate diesters (diSAmPAPs). Further high-resolution mass spectrometry (HRMS) screening is applied to identify further products and especially transformation products due to environmental processes.
Jun Huang is an associate professor at Tsinghua University, China. Gang Yu is a professor at Tsinghua University, China. Their combined work interest is in the area of PFAS emission from main industrial sectors; PFAS contamination in hot spots and its risk assessment; and PFAS degradation mechanism by advanced oxidation/reduction processes.
Q: Why is concern growing regarding PFAS?
James Dodds and Erin Baker: PFAS exposure has been linked to various adverse health outcomes such as thyroid disease, testicular cancer, kidney cancer, and pregnancy-induced hypertension. Thus, with each potential environmental spill or release, public health concerns rise further about PFAS, particularly with regard to drinking water safety.
Detlef Knappe: PFAS are of concern because many are persistent, bioaccumulative, and toxic. PFAS readily bind to proteins in blood and are transported throughout the body. As a result, they are potentially associated with a wide range of adverse health outcomes, including decreased immune function, cancer, elevated cholesterol, and ulcerative colitis, among others.
Also, the human body is not effective at eliminating PFAS, and half-lives of some PFAS in humans, such as perfluorohexane sulfonic acid, can exceed five years. Therefore, PFAS can accumulate in the body even when levels in drinking water are low. As a result, drinking water standards and health advisory levels are being set at low ng/L levels. For instance, the state of New Jersey promulgated a standard of 13 ng/L for perfluorononanoic acid (PFNA).
Another reason for concern is the fear of the unknown. The PFAS class contains thousands of compounds, but we currently lack fully appropriate analytical methods and information about the toxicity for most. As a result, people may wonder which PFAS compounds they might have been exposed to and what the potential health effects could be.
For example, in Wilmington, N.C., people drank water containing PFAS at levels on the order of 100,000 ng/L, likely for more than 35 years. The PFAS that were present in greatest abundance were first identified in 2015, and no information about their toxicity is available to date.
Bradley Clarke: The unique chemical properties that make PFAS so valuable for modern applications are often the very same that make PFAS incredibly problematic in the environment. First-generation persistent organic pollutants (POPs) were pretty bad, but we could largely predict how they would behave in the environment. PFAS are a new style of pollutant that don’t follow the ‘rules’ of traditional organic pollutants.
This is why regulators and scientists unfortunately failed to predict how these chemicals would move through the environment, and why we now have a serious problem of such widespread PFAS contamination of drinking water, agricultural land, and the domestic environment. Furthermore, we are only really just beginning to characterize the health impacts of a chemical that is ubiquitously present throughout the built and natural environment…”