Dr. Jessica Ray: PFAS in water supplies
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At least 45 percent of the nation’s tap water is estimated to contain chemicals called per- and polyfluoroalkyl substances, or PFAS.
On April 29, 2024, SciLine interviewed: Dr. Jessica Ray is an assistant professor of Civil and Environmental Engineering at the University of Washington. See the footage and transcript from the interview below, or select ‘Contents’ on the left to skip to specific questions.
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Introduction
[0:00:19]
JESSICA RAY: Hi, my name is Jessica Ray. I use she/her pronouns. I’m an assistant professor at the University of Washington in the Department of Civil and Environmental Engineering, and my group has been developing new materials to help remove or degrade contaminants in water.
Interview with SciLine
What are PFAS, and how are they used?
[0:00:42]
JESSICA RAY: PFAS are per- and polyfluoroalkyl substances—that’s the acronym. They are a class of thousands of synthetic chemicals that were originally manufactured and heavily used in the 1950s. When they were first manufactured, they were used as the active ingredient in fire suppressant foams that were applied in military bases to help extinguish flames, for example, when an aircraft were to ignite. And since then, they’ve been used in so many different applications and consumer products—such as shampoos, dental floss, nail polish. They’ve been used in waxy coatings found in food containers. They have also been applied as nonstick coatings, for example, in cookware—and can also impart water resistance. They’ve been used in outerwear to help with rain protection.
Why are PFAS called forever chemicals?
[0:01:44]
JESSICA RAY: They’re called forever chemicals because the physical and chemical properties of PFAS impart oil, water, and stain resistance, and they can also handle high temperatures as well. So because of all of those properties of PFAS, it makes them very difficult to degrade naturally in the environment or even in engineered processes such as how we degrade contaminants during water treatment. So those types of mechanisms for destruction don’t really work for PFAS.
How do PFAS move through the environment?
[0:02:22]
JESSICA RAY: Unfortunately, PFAS can exhibit long-range transport in the environment. They like to stick to solid surfaces like soils. They can be dissolved in water sources, and they can also be admitted into the Earth’s atmosphere. So because PFAS can permeate air, water, and soil, there are a multitude of exposure pathways for both humans and other biota. So, for example, if PFAS are present in ocean water, and then the fish ingest and become contaminated with PFAS, and then we consume those fish, then now humans have been exposed to PFAS. That’s just one route for example.
How pervasive are PFAS in drinking water?
[0:03:08]
JESSICA RAY: Because PFAS can permeate air, water, and soil, that leads to a multitude of exposure pathways, and unfortunately, researchers that have gone out and sampled drinking water sources across the country—and globally, as well—have detected PFAS and in many, many different drinking water sources. So in addition to PFAS detection and presence in environmental drinking water sources such as surface water and groundwater, PFAS have also been detected in bottled water as well.
What can you tell us about the health impacts of PFAS?
[0:03:48]
JESSICA RAY: From what I’ve read PFAS have been linked to liver tissue damage, kidney cancer. If infants are exposed to PFAS during pregnancy, then that can lead to skeletal variations in infants, low birth weight, accelerated puberty, and I believe PFAS have also been linked to impairments and antibody production and immune systems, as well.
How can individuals reduce personal exposure to PFAS?
[0:04:21]
JESSICA RAY: Something I tell my students in my class is, for example, if you’re cooking, you could purchase—if you know finances allow—if you could purchase stainless steel cookware, those don’t contain PFAS—or cast iron, very tried and true cookware that should not contain PFAS, as well. And fortunately, there’s been a lot of information shared with the public about PFAS and the threat that they pose to both humans and the environment. So you will now see products that explicitly state that they are PFAS free. So I would suggest looking for those, for the different products that we know contain PFAS. And also you could buy organic products, as well. Those should have lower PFAS loads in them as well.
How can individuals remove PFAS from their water?
[0:05:17]
JESSICA RAY: To my knowledge, there are a handful of companies that are selling essentially a version of a Brita water filter that are targeted for PFAS. I would say generally though, just using something like a Brita or Pur water filter at home should help reduce exposure to not only PFAS but other contaminants that might, you know, persist even in drinking water that’s distributed to your tap at home, for example. So I use one at home. It’s not specifically designed for PFAS, but any additional treatment that users can apply at home should help to reduce exposure.
What can you tell us about your research on removing PFAS from water?
[0:06:03]
JESSICA RAY: My research group is exploring two different approaches for treating PFAS in water. One approach is to remove or separate PFAS from water. And then the other approach that we’re exploring is to destroy PFAS in water. For the separation approaches, what we’re doing is looking at existing water treatment processes that are used in wastewater treatment and drinking water treatment—understanding their limitations with respect to PFAS separation—and we’re trying to modify those processes to either selectively target PFAS in water apart from other contaminants that could exist in water during treatment. And then we’re also investigating heavily engineered processes that can help to hopefully destroy PFAS in water.
How is your group trying to improve PFAS filtration?
[0:06:57]
JESSICA RAY: If you are filtering your water at home using a commercially available filtration cartridges, then the media inside those cartridges helps to remove a wide variety of contaminants. That could be heavy metals, other dissolved contaminants in water. And those are great for kind of broad removal of a multitude of contaminants. But often, PFAS in drinking water sources tend to exist in very, very low concentrations. And so there could be competition between PFAS that’s dissolved at low concentrations in water and the presence of other contaminants that exist at much higher concentrations. So one approach that we’ve been using is to develop new absorbance that helps to selectively target PFAS and a complex mixture of other contaminants that can be found in water as well. So my group has been developing this material for the last couple of years. And we have already been speaking to folks that can help to commercialize this technology so that hopefully we can, you know, apply this material in real life to treat PFAS and to help local consumers and users to apply these kinds of point-of-use treatments to help protect them from PFAS.
Are there alternatives to PFAS that are safer to use?
[0:08:23]
JESSICA RAY: There are researchers who are looking into what’s called green chemistry. So, can we design chemicals that behave very similarly to PFAS but aren’t as toxic and, of course, will break down in the environment, which PFAS, as we know, don’t tend to do? So, there is hope for the future, I would say, in terms of addressing this PFAS threat. So that’s definitely something I’d like to add—to end on a kind of more positive note about all of the kind of many negative aspects of PFAS.
