Last month, the Environmental Protection Agency proposed regulating two PFAS chemicals in drinking water: PFOS and PFOA. Also known as "forever chemicals" due to how difficult it is to clean them up, these compounds are associated with health problems.
"They're linked to certain cancers, including kidney cancer and testicular cancer, they're linked to liver health effects and to some developmental effects," said University of Pittsburgh engineering professor Carla Ng. "They are immune suppressants, so they reduce the efficacy of vaccines."
Ng studies how chemicals, like some PFAS chemicals, accumulate in the body. Last year she received a $500,000 grant from the National Science Foundation to study PFAS -- which stands for per- and poly-fluoroalkyl substances -- and to work on ways to remove them from the environment.
Many Pittsburghers aren't familiar with what PFAS chemicals are, or what they do.
"It doesn't sound nice, so I'm guessing it's something harmful," said Derek Blaise of the South Side. "Some sort of harmful chemical."
Across town in Oakland, student Rachel Jakielski had a similar reaction.
"I'm not really sure," Jakielski said. "I haven't heard anything about it."
PFAS chemicals are an overarching term for 5,000 different chemicals, and Ng estimates 3,000 are in active use.
"In general, they're what we think of as non-stick chemicals," Ng said. "So they're applied to surfaces and products in order to repel both oil and water."
Ng said PFAS are commonly found in nonstick pans, treatment for fabrics and carpets, as well as firefighting foams. The latter is a big source for emitting PFAS into the environment.
"The fact that these chemicals are extremely persistent, they never break down in the environment naturally means that once you emit them, they're really difficult to clean up," Ng said. "When we do find a toxic impact, then we're stuck with a huge cleanup bill."
There are two promising areas of research for getting rid of PFAS in the environment, according to Ng. The first is capturing long-chain PFAS in granular activated carbon to absorb them from water.
"But then you have to do something with that carbon that has accumulated all these PFAS," Ng said. "One of the best known ways to do this is through incineration, but there are concerns that if you don't do it properly, that's just going to wind up emitting those chemicals into the air."
This strategy is likely what the EPA will advise for reducing PFOA and PFOS in drinking water under the proposed regulation, said Ng.
The other area of active research is biodegrading PFAS with microbes.
"There are some promising new technologies that seem to be able to do that," Ng said. "However, many of the efforts I've seen take a long-chain PFAS and convert it to a shorter PFAS, and the shorter ones are more mobile, more water soluble, and are much harder to remove from our drinking water."
Due to how widespread the PFAS issue is, Ng advises researchers interested in the subject to get involved.
"This is an all hands on deck opportunity," Ng said. "[We're] trying to find inventive new ways to remove these chemicals."