Per- and polyfluorinated alkyl substances (PFAS) are man-made chemicals that are useful in a variety of industries because of their durability, but do not naturally break down in the environment or human body. With evidence showing that PFAS may have adverse effects on human health, Carla Ng, assistant professor of civil and environmental engineering at the University of Pittsburgh Swanson School of Engineering, wants to further investigate the potential impacts of these chemicals and identify ways to remove them from the environment. She received a five-year, $500,000 NSF CAREER award to pursue this research.
Because of their useful oil- and water-repellent properties, PFAS are used in many consumer products, industrial processes, and in firefighting foams, but unfortunately, their manufacturing and widespread use has contributed to the undesired release of these chemicals into the environment. According to Dr. Ng, more than 4,000 different kinds of PFAS may have been for decades, and detailed toxicity data does not exist for the large majority of these.
"One of the pressing concerns with PFAS is its adverse effects on human health," said Dr. Ng. "Conventional drinking water treatment is not effective at removing most PFAS from water so they can build up in the bodies of humans and wildlife, disrupt normal development, and impair the immune system. Some PFAS have been associated with increases in kidney and testicular cancers in humans."
The goal of Dr. Ng's CAREER award is to address these issues through a complementary approach using predictive modeling and experiments.
"In this project, we will use molecular and organism-scale models to conduct large-scale predictive screening of PFAS hazards," said Dr. Ng. "With the information gathered from our predictive models about the structure-interaction relationships, we will design new bio-inspired sorbents to remove PFAS from water.
"Because we have so little information about potentially thousands of these substances, we cannot experimentally assess each one; the costs would simply be too great in time, testing, and resources," continued Dr. Ng. "This is where models can be very powerful tools because they allow researchers to concurrently conduct virtual experiments on many chemicals. When these models are tied to targeted experiments, their predictions can be evaluated and the models improved to be more accurate."
Beyond understanding the effects of these chemicals, models can also provide clues on how to remove them from the environment. Dr. Ng will employ the very characteristics that make PFAS so dangerous against them. By using her models to discover which biological molecules react strongly with PFAS, her group will be able to design a new class of selective sorbents that remove them from water in an efficient and targeted way. She hopes that the knowledge gained during this five-year CAREER award will also help identify hazardous properties in future chemicals.
An important objective of this CAREER award is to engage middle and high school students in STEM research by exposing them to the power of modeling and simulation. To do so, Dr. Ng will implement formal educational programs and informal STEM outreach. She plans to elevate K-12 and undergraduate education through the use of collaborative model-building in a game-like environment.
"The agent-based modeling language NetLogo is a freely available and accessible model-building tool that can be equally powerful for cutting edge research or for students exploring new concepts in science and engineering while learning useful model-building and coding skills," said Dr. Ng. "I hope to enhance systems-level thinking and self-confidence among students in STEM so that we can cultivate diverse cohorts of future STEM leaders."
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