Last month, an Ohio court certified a class action lawsuit brought by lawyer Rob Bilott that would cover 7 million people – and at some point possibly everyone living in the United States – who have been exposed to certain hazardous “forever chemicals” known as per- and polyfluoroalkyl substances or PFAS. The chemicals have been linked to cancer, birth defects, kidney disease and a range of other human health problems. They are called “forever chemicals” because they do not naturally break down, persisting indefinitely in the environment. Two types of PFAS – PFOA and PFOS – have been found to be so harmful that they are being phased out of use. In addition to US multi-national company 3M, the class action lawsuit names 10 other companies that produce PFAS, which are used to make cookware, food packaging, water-resistant fabrics, firefighting foam and other products. The Biden administration last year pledged to undertake a massive PFAS mitigation strategy at a cost of more than $10bn. The Guardian spoke to Bilott about his lawsuit. The remarks have been edited for length and clarity. You have spent 20-some years now focused on exposing the danger of a class of chemicals we call PFAS, using litigation to try to hold companies involved in spreading PFAS accountable, and pressuring regulators to step up and do more to protect the public. You’ve written a book, Exposure, been featured in the New York Times as “The Lawyer Who Became DuPont’s Worst Nightmare,” and your legal battle has been made into a Hollywood movie called Dark Waters, as well as a documentary. Why are you so passionate about this issue? This is a worldwide public health threat. It’s very frustrating when you step back and you look at the science that has gotten even clearer over the years about how dangerous these chemicals are and how widespread their use is. The companies knew that if they put these chemicals out into the world they were going to get into our water, into our soil, into the wildlife, into us, yet they did it anyway. And now, after making billions of dollars for decades, those same companies are fighting any responsibility and trying to shift the cost of cleaning this mess up on to all of us. I’m trying to do what I can to make sure that not only is the health threat addressed but that the right people, the ones who actually caused the health problems, are held responsible - not all of us. Most people might associate your work with your battle against DuPont, a large manufacturer of PFAS chemicals used to make such things as Teflon coatings in cookware. But now you’re taking on many more manufacturers. What do you hope to achieve with this case? We first uncovered the existence of these chemicals in litigation against DuPont, which had been purchasing a chemical called PFOA from its manufacturer, 3M, and using it to make Teflon. We slowly started to realize that we’ve got not just PFOA but this bigger group of PFAS chemicals now being found in the environment, and in blood. But we were told that all the science that had been done was only on PFOA and that nobody had done similar research yet on these other chemicals. The companies said it was up to the exposed people, it was their burden, to prove that these other PFAS chemicals were causing harm. So in 2018 we filed the class action. The goal is not to get money damages but to have a federal court require that a new scientific panel be set up that would have the ability to look at this mix of PFAS chemicals in our blood and confirm the extent to which they are in fact causing harm. We want the companies to fund independent scientists to do whatever science might be needed to confirm these harms. Last October President Biden announced a plan to “prevent PFAS from being released into the air, drinking systems, and food supply… and expand cleanup efforts to remediate the impacts of these harmful pollutants.” That plan is expected to cost taxpayers billions of dollars. Biden has set aside $10bn just to deal with PFAS in drinking water. You recently sent a letter to the Biden administration addressing the plan, offering your assistance and support. But you also expressed a very firm opposition to taxpayers’ money being used for cleanup of PFAS pollution. Are you frustrated not just with the manufacturers but also with the EPA? It is frustrating that we’ve had several different PFAS “action plans” announced over the years dating back to 2009. Nothing happened with the first plan and then we had another plan announced in 2016. More promises were made and again nothing happened. And so we’ve got this new plan that has been announced. (But) we’re still seeing debate about to what extent should these materials be regulated, should they be declared hazardous or not. What I came to understand after dealing with this for so many decades is that we have a real systemic problem with the way our regulatory system is set up, the way in which science is generated, the way in which papers are published, peer reviewed, how that all interacts with our legal system, who has the burden of proof, who is being told they have to prove whether a chemical is safe versus whether it is harmful. All that creates a perfect storm of inaction. The only way people have been able to get clean water, to get compensated for the damage, the cancers that have been caused, is to go into our court system and try to fight this out in court for years. It is almost as though there is this intentional system of roadblocks baked into the system. So it sounds great, telling the public that we’re moving forward, we are going to actually start cleaning this stuff up, we’re going to allocate billions and billions of dollars to do that. But the money should not be coming from us, the exposed people. The taxpayers should not have to fund cleaning this up. We shouldn’t have the federal government essentially bail out these chemicals companies by allocating billions that the companies should be spending to clean this up. You have gained access to voluminous files of internal documents from the various companies you’ve sued over PFAS. Many of these documents show that the companies were aware decades ago that PFAS was harmful, and notably that it was spreading widely, accumulating in humans. Can you elaborate on that? It’s very eye opening when you start digging into the internal files of what these companies knew, what information they had access to going back decades, that they simply didn’t share with the rest of us. For example, one of the things we found in the internal files of the main manufacturer of the chemical PFOS, was that this company was well aware by the 1970s that PFOS was being found in the general US population’s blood and was being found at fairly significant levels. In fact by the 1990s, 3M’s own scientists had sat down to calculate what a “safe” blood level would be for PFOS. At the time, they knew that the level of PFOS being found in the general US population’s blood was around 30 parts per billion. And when this internal 3M scientist sat down to calculate a safe blood level, the number he calculated was 1.05 parts per billion. Some 30 times lower than the level that was actually being found. Why weren’t the rest of us told that? Why weren’t we warned? We only find out about that decades later. Documents like that make it clear the potential risk to human health was recognized decades ago. Yet here we are in the year 2022 still arguing about whether we should take steps to get rid of them – and who should be held responsible for all this. This is one of the reasons why I’m doing everything I can so people can see the facts for themselves and draw their own conclusions about who ought to be responsible for the threat that has been caused.