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The Silent Infiltrator: ‘Forever Chemicals’

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Anshu Bahanda: Welcome to this episode of Wellness Curated. This is your host, Anshu Bahanda, and as you know, the aim of this podcast is to bring you tips, tools, techniques, approaches, ideas that will help you lead a healthier, happier, more hopeful life. Today, we’re going to be discussing forever chemicals and their harmful effects on the environment with Stuart Khan. He’s the director of the Australian Graduate School of Engineering, AGSE, and professor of Civil and Environmental Engineering at the University Of New South Wales, UNSW. He’s also dedicated his time as the leader of the Trace Chemical Contamination Research Stream at the UNSW Water Research Center. Welcome to our chat, Stuart, and thank you so much for taking out the time to be with us today.

Stuart Khan: Thank you, Anshu. It’s a pleasure to be with you. 

AB: Thank you. So, Stuart, can you explain to us in layman’s terms, what are PFAS, or forever chemicals and why are they called forever?

SK: Yes. So the usual name is a fairly technical term. So PFAS is what we call them, which is an abbreviation for ‘per- and polyfluoroalkyl alcohol substances’, which probably doesn’t mean very much to most people. So what they are is they’re a very large group of chemicals, thousands of different chemicals. And if you think of many of the chemicals that we are familiar with, hydrocarbons, so things like oils and gasoline and cooking oil and many of the sort of natural products that we’re familiar with, as well as many plastics, these things are made out of carbon and hydrogen. So it’s a very common combination, carbon and hydrogen, to make hydrocarbons that occur naturally in the environment. What does not occur naturally is replacing a large number of the hydrogen atoms with fluorine atoms. So synthetic chemists have been very clever and were able to produce these new chemicals that are carbon and fluorine instead of carbon and hydrogen. They don’t occur in the environment. But we’ve identified that there are useful applications of these chemicals and that’s why we’ve been manufacturing them since the 1940s. And the reason that they’re called forever chemicals is because they really don’t break down in the environment. They will last centuries or longer when we discharge them to the oceans, or landfills, or wherever our waste might end up.

AB: Now, the philosophy that a few of us have grown up with, I mean, I grew up in India, and the philosophy I grew up with was that we were meant to live on this planet and tread gently and not leave any or leave as minimal a trace of our existence. From what you’re telling me, forever chemicals are completely different. It’s exactly the opposite of this philosophy. Is that right?

SK: Yes, we really have not respected that philosophy at all. When we began manufacturing forever chemicals in the 1940s we were looking at the useful properties of those chemicals and there are some very useful properties of those chemicals and we were not paying appropriate attention to what would happen at the end of life of the products that we were manufacturing. Where would these chemicals end up? It really doesn’t seem to have been the subject of significant research or significant attention to even ask that question: what will be the long term fate of these chemicals and does it matter? So yes, we were not treading lightly and we weren’t thinking about treading lightly and we’ve really messed up in that sense, because we’ve now manufactured a large number of chemicals that have contaminated widespread around the world that we really don’t know how to fix, that we really don’t know what to do about it. And it’s a problem that is going to require a lot more research and investment before it’s properly solved. 

AB: So Stuart, just to make this more tangible for our listeners, can you shed some light on what are the everyday products, the common household products that might contain them and why has it reached this stage where it’s in people’s houses?

SK: Yeah, so one of the main properties of these chemicals which made them very attractive for use is that they repel water and they repel stains. So you might remember a product called Scotchguard which was promoted to spray on your clothes and on your upholstery, on the lounge, and everything because it would protect it from stains, red wine or gravy or whatever stains might come along, and it’s very good at doing that. It repels those chemicals and so therefore they wash out of the material very well when it’s been treated with Scotchguard. Scotchgard doesn’t exist as a product anymore but many of these chemicals are still being used for much the same purpose. So stain resistant carpets, for example, have been treated with forever chemicals, upholstery lounges, car seats, seat covers, steering wheel covers, many of these things that helps them to stay clean to a large degree and also waterproofing. So when you go camping now, you have waterproof clothes that you can purchase and waterproof shoes. Your tent is much more waterproof than it was 30 or 40 years ago and that’s because those products have all been treated with forever chemicals which repel the water, they repel the rain. So we stay dry and comfortable but we do so by introducing this legacy of these chemicals which are going to keep repelling water and keep hanging around for a very long time.

AB: Also, can you shed some light on these chemicals? What happens when they enter our bodies and the environment?

SK: So when they enter the environment as we’ve discussed, they hang around, they don’t break down, they’re also different to some other pollutants. Often when we think of some of the conventional pollutants, like DDT and other pesticides, they tend to stick to soil. So they stay in one place. There’s a contaminated site. That site stays contaminated, but it doesn’t move to other areas. PFAS is actually very mobile in the environment. So you can contaminate one site and you will find that the groundwater, perhaps 10 km away, might become contaminated because the groundwater has moved underground and the PFAS will move with it forever. The chemicals will move with it. So in the environment it behaves in a much more difficult way than other chemicals in our bodies. PFAS does accumulate, and so we’ve identified there are many species, particularly fish, that have been exposed to contaminated water, where you will see higher concentrations of these chemicals in a fish body. Usually it’s the upper predators in the food chain that accumulate toxic chemicals, because the small animals accumulate small amounts of these chemicals. And then as you go up the food chain, it’s the top predators, the apex predators, that are eating all of the smaller animals, and so they’re getting the extra accumulation along the way. So we see it in things like crocodiles, alligators and snakes, things that eat other species— we tend to see higher concentrations of lots of chemical contaminants, including PFAS.

AB: So if you see it on predators that eat other species, what about humans? And what are the implications of this on human health and the environment?

SK: So we do know that practically all of us, all 8 billion of us, just about have been exposed to PFAS. In most developed countries and developing countries, if you do a survey of some of these chemicals in people’s blood, it’s usually well above 90% of people who will have detectable levels, and sometimes it’s practically 100%. So we’ve all been exposed because we’re all coming into contact with some of those consumer goods that I described. PFAS is also used a lot in food packaging, especially grease-resistant food packaging, takeaway boxes, the shiny ones that are able to get wet and they don’t fall apart. So again, very useful properties. But many of these actually do contain per-fluorinated forever chemicals. So there are very few of us who have not been exposed. It is one of those chemicals that can be passed through mother’s milk to babies. So even very young infants, even in Europe, we know that babies and the blood that they share with their mother can contain, and usually does contain measurable trace concentrations of these chemicals. So we’ve all been exposed. I guess if you wanted to look at that in some kind of positive light, which is not so easy, but the positive side of it is we know that it can’t be so toxic that it’s killing us all very rapidly. Life expectancies are increasing around the globe, despite lots of adverse health indicators such as obesity and things like this. So we know there’s lots of suspicion around the toxicity, the particular health effects that PFAS might cause to people. But there’s not a lot of evidence at the moment. And so we’re struggling to really join the dots about some of the evidence that we see and some of the concerns that we have around how toxic these chemicals might be. But that evidence hasn’t been so strong that we’ve actually been able to observe adverse human health outcomes that we can confidently say are a result of that exposure to PFAS.

AB: So, Stuart, I don’t know, is there any research which shows you that forever chemicals of PFAS are carcinogenic?

SK: So many, many health outcomes such as cancer have been studied with PFAS and very often the answer is yes, there is evidence that we can point to. But when it comes to human health, that evidence is often mixed and it’s not always reliable. So we do consider that there is evidence for some other species, rats and mice which have been exposed to very high levels of PFAS and have developed liver cancer and I think some other types of cancer as well. And often that’s a good indication that these same chemicals might cause cancer in humans, but it’s not usually considered enough evidence on its own. So normally we would be looking for additional evidence, a plausible mechanism for how that cancer is caused before most agencies would consider that likely carcinogen for humans. So yes, it’s suspected. There’s good reason to be concerned that it might cause cancer, but the jury is still not quite in on whether it really does [develop cancer] in people or not.

AB: Okay, and what about the long term impact on the ecosystem and on wildlife? Do we know that? Because it’s not that long ago that we discovered forever chemicals.

SK: Right. We’ve only been manufacturing them since the 1940s. They’ve been in high use since the 1950s or 60s. So yeah, maybe come back and ask me that question in another 40 years time. There’s probably a lot that we haven’t found out yet and we haven’t had the opportunity to find out about potentially really long term, possibly intergenerational impacts as a consequence of PFAS exposure. One of the real difficulties of these chemicals is that there’s so much that’s unknown. And when it comes to long term risks and long term exposure, to some degree, we really need that long term to pass before we really have a good understanding of what has occurred.

AB: What about the medium term? What do we know about the medium term impact?

SK: There are all sorts of effects that we’ve seen in controlled studies, in laboratories. We’ve spoken about cancer, we’ve seen low birth rates. There are many adverse health outcomes. The one that’s probably causing the most concern to regulatory agencies and is really driving what we consider to be the safe levels of exposure continually downward is: concern around immune response. So people who have high levels of forever chemicals in their blood, seem to be having an association where they don’t produce antibodies as well as people with less high levels in their blood. And so that means that when we have a vaccine, we get immunisation against something, the flu or whatever it might be, there’s concern that the vaccine will be less effective as a consequence of the PFAS that’s in our bodies. We don’t really understand why there aren’t good theories that sort of join the dots for why that should be. But there does seem to be some circumstantial evidence, some association between higher PFAS exposure and reduced immunity following immunisation.

AB: Right. So what you’re saying to me there’s some research that it stops vaccinations from working to their fullest.

SK: Makes them less effective.

AB: Makes them less effective. Okay.

SK: So it increases your risk of dying as a consequence of an illness that you might otherwise have been vaccinated against.

AB: Okay. And is there a certain area where the concentration is more?

SK: Yes. We do see higher concentrations in urban areas, often, particularly in areas where these chemicals may have been manufactured. There are certain countries that have had big manufacturing facilities for these chemicals. I live in Australia, and we don’t manufacture it in Australia. But PFAS is still everywhere. So it’s not just the manufacturer. It’s the distribution of all of the consumer products that we use, and then they end up in landfill. So landfill sites are hotspots for PFAS. Landfill leachate that might be released from the landfill very often contains high concentrations of PFAS sewage. The wastewater that we discharge into the environment is often an important source. There are a group of these chemicals that have been used for putting out fuel fires. They’re very effective for smothering a fuel fire. So if a tank of petrol is on fire, you don’t spray water on it. You spray these particular PFAS chemicals on it, and they smother the fire. And so often, areas where there has been firefighting training, we see very highly contaminated sites. And we have quite a few of those in Australia where there has been training of firefighters to put out fuel fires, as well as airports and defence sites where there is a lot of liquid fuel lying around. And there has been either actual extinguisher firefighting at those sites or training to fight fires at those sites. Very often, the fire fighting foams have been very poorly managed. They put out the fire, they end up on the ground. Nobody does anything more about them. They soak into the ground, and they contaminate the groundwater. So they’re very common hotspots that we see.

AB: And Stuart, you’ve done a lot of research on water and how to remove PFAS from water. Now can you explain the process to us and what are the current limitations, if any, of the technology that is being used to do so?

SK: There are big limitations. So we are able to treat water. There are various treatment processes that we can use if we have a contaminated water supply, and we want to produce very clean water from that. One of the key processes for forever chemicals is an ion exchange process. So it’s like a resin, and we can filter the water through the resin, and the resin will pull out the PFAS chemicals, and it will give us clean drinking water that we can supply to people as a good drinking water source. That’s great, but a key limitation there is that— all it’s doing is separating the PFAS from the water. It doesn’t actually destroy the PFAS, so we still end up with this waste material, at the end, that needs to be disposed of, that is highly contaminated with PFAS.

AB: And what do you do with that? Do you bury it in a landfill and therefore create another hotspot? Do you throw it in the ocean? 

SK: There’s no really sustainable solution for how we ultimately dispose of that PFAS. Even though we’ve done a really good job of treating the water and making clean drinking water, it’s really a problem. We need a treatment process that will actually break down and destroy the PFAS rather than just separate it out of the water.

AB: So your normal everyday water filter that people buy, how good are those at removing PFAS?

SK: Generally not very. So there are lots of different water filters that people buy. Some of them are activated carbon, so it’s made out of charcoal, and some PFAS will absorb onto activated carbon. You can remove PFAS with activated carbon, but you need to really maintain that filter because you don’t destroy the PFAS, it just sticks to the carbon and only a certain amount can stick. And eventually your filter will become full of as much PFAS as it can hold onto, and you’ll start removing it less well, fairly quickly. There are other types of filters that some people have for removing salt. Reverse osmosis filters, they can be very effective, but they’re very expensive to operate. Most people… Unless you have a serious salt problem where you live, there are some areas in the world where people do use reverse osmosis filters, but most normal households would not have a reverse osmosis filter because it’s a high energy, expensive way to produce drinking water, and most people wouldn’t consider that an affordable thing to do.

AB: Okay, and you were talking about resin as a way of removing PFAS from water. Are there other advances in this area?

SK: Constantly. In my field, PFAS is something that’s been very high on the radar for the last decade. There’s been lots of research funding coming from different governments all over the world to investigate opportunities to better break down and remove PFAS from drinking water. So, yes, we’re seeing lots of different solutions coming all the time, and very often you read a headline: scientists have discovered a way to break down PFAS, and the problem is all solved. It’s usually not solved because nearly all of these solutions are very high energy solutions and therefore very expensive solutions. We sell drinking water to most communities. What people pay for what comes out of the tap. Obviously, it’s different from country to country, but let’s say it’s about $1 per litre— would be a reasonable estimate, $1 to $5 per litre. So that tells you how much money you can spend treating that water. You can’t spend $50 per litre treating the water and then sell it for one to $5 per litre to customers, that’s not a sustainable solution. So we need to find treatment processes that are affordable, that we can implement without sending the price of drinking water beyond what most people are going to be able to pay for. Yeah, there are some real whiz bang, hi-tech technologies that can break down PFAS, but they’re very expensive, very energy intensive, and not realistic for big scale drinking water supplies.

AB: Give us an example of something.

SK: Well, a lot of them are high temperature processes. So by using high temperature and high pressure, you can pass PFAS through ultimately a flame or a plasma. And some of these plasmas will break down any chemical. They’ll rip apart the bonds and break down all chemicals that are present. But there’s no city in the world that uses those types of treatment processes to treat and supply their drinking water. So they’re great on paper, they’re great in a research article. They get us excited about the possibilities in the future, but it will be a longtime before they translate into real practical outcomes for removing PFAS from drinking water.

AB: And tell us, in the context of mitigation and remedial strategies, what do you think has been the contribution of industry?

SK: A whole industry has sprung up around the problem. So we have so many contaminated sites around the world now that there are private and public water treatment companies that compete with each other to come up with the best, most cost effective, affordable, effective solution for producing drinking water. So there are little mobile treatment plants that use the ion exchange technologies that I was referring to. Some of them use activated carbon. There is a big industrial response, but to me that response is addressing the symptoms rather than the cause. We’re polluting the environment and then we’re seeing if we can clean up the water before people drink it, whereas we really need to go back a few steps in that process and implement solutions that don’t lead to the pollution in the first place. And for that, there’s a big role for chemists. We need people to design better chemicals. Chemicals that will do some of the things that we wanted PFAS to do and we’ve designed PFAS to do, but won’t have the negative consequences of A- being so resilient in the environment that they will last for centuries, and B- the toxicological concerns, the concerns about the potential impacts to human health and the health of other environments, of organisms. So there is a whole field now that’s called Green Chemistry. And green chemistry is all about trying to manufacture better products so that we can avoid these types of impacts and not have to invest all of our time and energy in cleaning up after. 

AB: So in terms of policy and governments, what are they doing about PFAS and secondly, about developing new products like you talked about green chemistry? And are they doing enough, you think?

SK: Well, it’s certainly taken a long time. It’s taken a long time for us to become focused on this issue, about 50 years too late, certainly. Governments are very focused on PFAS now because it causes lots of governments a lot of headaches, because we’re seeing a lot of concern around the public health implications of some of the contaminated sites which governments don’t have the evidence to be able to say the PFAS is not causing, so it’s a very difficult situation. Governments run defence sites, and defence sites are some of the most contaminated sites that we know of. So in many countries over the last ten years, in particular, governments have become quite active in trying to ban some uses of PFAS, starting to develop environmental management strategies for PFAS. Two PFAS chemicals were actually added to the Stockholm Convention on Persistent Organic Pollutants a few years ago. And so there is effectively an international convention or treaty that requires the countries that have signed the Stockholm Convention to implement remediation and control plans, plans for how they will keep PFAS out of the environment and how they will protect people in the environment from these chemicals. It wasn’t there at the start when the Stockholm Convention was originally ratified, and certainly when Australia signed on, the PFAS chemicals were not there. So we don’t actually have any international obligations yet because we haven’t ratified that addition. But at least it’s there. And in some parts of the world, some countries are really starting to move on improving their environmental management of these chemicals.

AB: And is that the only international treaty that exists to control PFAS?

SK: It’s one of the most important international treaties. So it goes well beyond PFAS. It’s Persistent Organic Pollutants, so it’s lots of different polyaromatic, hydrocarbons and other chemicals that have been on the radar for a bit longer than PFAS has. So yes, that will be an important convention, especially as more and more countries actually ratify that addition of PFAS coming into the list of chemicals. But no, there are other international treaties that particularly require labelling and information on imports, so to say, chemicals. So consumer products that are being imported from one country to another. For countries that have ratified these conventions, there are requirements to be transparent and to report what’s actually present. Because in many cases, we don’t actually know there are consumer products that have been exported all around the world, but you don’t actually know every single chemical that they’ve been treated with. So you don’t know how much PFAS you’re importing and being exposed to as a consequence.

AB: That’s really frightening, the fact that we’re still not clear about where it’s contained, what the long term side effects are, what it’s doing to us, that’s just really frightening. But Stuart, I was looking at your Twitter feed and that read, Director of Australian Graduate School For Engineering and then all your wonderful jobs. Now as parents, that’s something really scary. For those of us who are parents, what are we leaving behind for the next generation? And also, as a society, how do we need to change our consumption habits so that there’s less PFAS included in what we consume? And as consumers, can we demand more transparency?

SK: Yeah, so some really good questions there. And you’re right, we mentioned it before when you said, what are the long term implications of PFAS and I said, ask me in 40 years. I probably won’t be around in 40 years, but my son will be and maybe his children will be. And that whole generation.

AB: You might be around with longevity and all that. You know with medicines.

SK: I might just make another 40 years. But you’re right, we do need to be thinking about the world that we’re leaving behind for future generations and we need to do a better job of that than the last few generations have done when it comes to chemical pollution on the planet. So actually, I hope that my son’s generation will take up that huge responsibility given the legacy that we’ve left them. But I hope that they will be carrying on the research, carrying on the attention to the problem, and hopefully solving some of these problems so that they become more temporary than they seem at the moment. They don’t seem very temporary, we call them forever chemicals. Hopefully that might change in the future with better understanding. 

In terms of how people might be able to minimise their own exposure and protect their families from some of these chemicals— one thing is to simply look at the ingredients of consumer products that we buy and particularly anything that might be promoted as being water-resistant or stain-resistant. Look for the words fluoro or polyfluoro or perfluoro. That’s usually a very good indication that some of these forever chemicals might have been used in the manufacture of those goods. And then there are some that are just very well known to contain these chemicals. Microwave popcorn bags are famous for having very high concentrations of these contaminants. But lots of food packaging, lots of things that are going to contain something that might be greasy or wet, that otherwise cardboard wouldn’t survive very well with. Treating these things with per-fluorinated chemicals makes a much more robust container. So avoiding those types of containers is not very easy, I know. Nonstick fry pans, the teflon type fry pans— I hate to tell people to avoid those because I love nonstick fry pans. They help us to use less oil and fat in our cooking. But they are a known source of perfluorinated chemicals. And so if somebody’s actively concerned about trying to reduce their exposure, that’s one way to do it.

AB: So this was in terms of things that we would buy for our listeners. Give us more ideas on how they can reduce their exposure in general because if it’s there in the water, is it there in the air? If it’s all around us, how does one prevent or reduce our exposure to it?

SK: Ultimately we’re never going to be able to reduce it completely because, yes, it is in many places. We can measure PFAS in water and you can measure PFAS in air. There was a couple of papers recently, very famously showing that you can measure very low concentrations but detectable concentrations in Antarctica. You can also measure PFAS on the Tibetan plateau. So right up in the Himalayas, some of the most remote places on Earth, you can measure these chemicals. They get distributed by rain, they’re soluble in water, they’re taken up in evaporated moisture, the rain clouds move around the earth and it literally rains PFAS on most of our cities. So you can’t actually avoid these substances completely without isolating yourself in a cling film bubble. But there are some things that you can do to manage your exposure. And if you’re in an area, where you know that you have a highly contaminated water supply, then there is an opportunity to potentially treat that water by using under sink filters, activated carbon and ion exchange filters that we spoke about, or potentially just finding an alternative source of water for drinking. The last thing I want to recommend to anybody who is buying bottled water— I hate bottled water but if you have contaminated drinking water then you have a very good excuse of course, for buying bottled water. So if you have to replace your drinking water supply because it’s unsafe then that’s what people should be looking for the opportunities to do.

AB: And Stuart, is PFAS in the air as well?

SK: Yes, to a low degree. So breathing in PFAS is not one of our major exposure routes. We have chemical analytical detection devices now that are so sensitive that we can measure minute concentrations. So, yes, we can measure PFAS on the dust that blows around in the air, but the concentrations that were exposed to by air and dust are generally lower than the concentrations we will be exposed to by many of those consumer goods that we were talking about. Carpets, upholstery, car seat covers. All of these things are likely to be much greater sources of exposure than what we might actually breathe.

AB: And what about resources? Can you recommend any resources so we can all stay in touch with developments in this area?

SK: There really is a lot, because governments and lots of the non-government organisations have become very interested in PFAS over the last decade. To me, my most sort of fundamental, reliable source that I go to is: the World Health Organization. The World Health Organization will certainly have resources describing the risks, the potential routes of exposure of PFAS, and describing how people might be able to minimise their exposure to PFAS. So it’s usually the WHO is my first port of call, but you will find good resources from environment agencies and governments from practically any country, now I think.

AB: Magnificent. So Stuart, at the end of every chat, we do a quick rapid fire round to summarise the chat. Some commonly used products that may contain PFAS.

SK: Some commonly used products that may contain PFAS, any stain-resistant products, carpets, upholstery, any water-resistant products such as water-resistant coats, clothes, shoes, tents, very often contain PFAS.

AB: One surprising impact of these chemicals on your body and on the environment.

SK: So many impacts that people have looked for, that we don’t necessarily have a good theory for why PFAS should cause low birth rates, why PFAS should also cause cancer. All of these impacts, I would say, are surprising. We thought these chemicals were very inert, they didn’t react very much and to a large degree they are. But we are constantly being surprised that they do react with things.

AB: A step we can take to reduce the exposure to these chemicals.

SK: Reduce exposure to water-resistant food packaging.

AB: Thank you very much. Thank you, Stuart, for your time. What an incredible chat we’ve had today. Thank you.

SK: Thanks Anshu, I’ve really enjoyed it.

AB: Thank you for being here with us today. I hope you learned something new and I hope we brought you a little closer to leading a healthier, happier, more hopeful life. If you enjoyed this, please press like and please encourage your friends and family to subscribe to our channel. I would also love to hear from you. So any topic, suggestions or questions, please send me an email at Anshu@WellnessCurated.Life. I repeat Anshu@WellnessCurated.Life. And on popular demand we’ve also published this book of affirmations. If you would like a copy, please send me an email as well. This gives you an affirmation for every day of the month and this is something that I used and that’s why we published it. Thank you so much and see you next week.