Why PFAS Chemicals Are So Difficult to Remediate In this Q&A, Konstantinos Kostarelos, PhD, discusses new insights he's gained through his team's recent research on PFAS in firefighting foam April 29, 2021 Konstantinos Kostarelos, PhD. Konstantinos Kostarelos, PhD, associate professor at the Cullen College of Engineering at the University of Houston, talks to senior digital content editor Rachel Muenz about his team’s recently-published research focusing on per- and polyfluoroalkyl substances (PFAS) in firefighting foam and why these chemicals are difficult to remediate from the environment. Q: Why is research into PFAS chemicals so important? A: First, we should note that there are several compounds in the group of chemicals known as PFAS that have been shown to cause adverse health effects. According to the US Environmental Protection Agency, PFOA [perfluorooctanoic acid] and PFOS [perfluorooctanesulfonic acid] can cause reproductive and developmental, liver and kidney, and immunological effects in laboratory animals. The fact that these compounds are known to resist degradation,