‘Please come and see me because I’ll be dead soon’: how Michael Sheen got sucked into a forever chemicals exposé

An opera-loving member of high society turned eco-activist who was forced into police protection with a panic button round his neck . A Hollywood actor who recorded said activist’s life story as he was dying from exposure to the very chemicals he was investigating. Throw in two investigative journalists who realise not everything is as it seems, then uncover some startling truths, and you have “podcasting’s strangest team” on Buried: The Last Witness.

On their award-winning 2023 podcast Buried , the husband and wife duo Dan Ashby and Lucy Taylor dug into illegal toxic waste dumping in the UK and its links to organised crime. This time, they focus on “forever chemicals”, specifically polychlorinated biphenyls (PCBs) and set out to discover whether one whistleblower may have been decades ahead of his time in reporting on their harmful impact.

“It’s amazing how big the scale of this story is,” says Ashby, as we sit backstage at the Crucible theatre, where they are doing a live discussion as part of Sheffield DocFest. “With this series, we don’t just want it to make your blood turn cold, we want it to make you question your own blood itself.”

It all started when Taylor and Ashby were sent a lead about the work of former farmer’s representative Douglas Gowan. In 1967, he discovered a deformed calf in a field and began to investigate strange goings on with animals close to the Brofiscin and Maendy quarries in south Wales. He linked them to the dumping of waste by companies including the nearby Monsanto chemical plant, which was producing PCBs.

PCBs were used in products such as paint and paper to act as a fire retardant, but they were discovered to be harmful and have been banned since 1981 in the UK. However, due to their inability to break down – hence the term forever chemical – Gowan predicted their legacy would be a troubling one. “I expect there to be a raft of chronic illness,” he said. He even claimed that his own exposure to PCBs (a result of years of testing polluted grounds) led his pancreas and immune system to stop working. “I’m a mess and I think it can all be attributed to PCBs,” he said.

However, Gowan wasn’t a typical environmentalist. “A blue-blood high-society Tory and a trained lawyer who could out-Mozart anyone,” is how Taylor describes him in the series. He would even borrow helicopters from friends in high places to travel to investigate farmers’ fields. Gowan died in 2018 but the pair managed to get hold of his life’s work – confidential reports, testing and years of evidence. “I’m interested in environmental heroes that aren’t cliche,” says Ashby. “So I was fascinated by him. But then we started to see his flaws and really had to weigh them up. My goodness it’s a murky world we went into.”

The reason they were able to delve even deeper into this murky world is because of the award-winning actor Michael Sheen who, in 2017, came across Gowan’s work in a story he read. He was so blown away by it, and the lack of broader coverage, that he tracked him down. “I got a message back from him saying: ‘Please come and see me because I’ll be dead soon,’” says Sheen. “I took a camera with me and spent a couple of days with him and just heard this extraordinary story.”

What Gowan had been trying to prove for years gained some traction in 2007, with pieces in the Ecologist and a Guardian article exploring how “Monsanto helped to create one of the most contaminated sites in Britain”. One was described as smelling “of sick when it rains and the small brook that flows from it gushes a vivid orange.” But then momentum stalled.

Years later, in 2023, Ashby and Taylor stumbled on a recording of Sheen giving the 2017 Raymond Williams memorial lecture, which referenced Gowan and his work. Before they knew it, they were in the actor’s kitchen drinking tea and learning he had conducted a life-spanning seven-hour interview with Gowan before his death. So they joined forces. Sheen isn’t just a token celebrity name added for clout on this podcast; he is invested. For him, it’s personal as well as political. “Once you dig into it, you realise there’s a pattern,” he says. “All the places where this seems to have happened are poor working-class areas. There’s a sense that areas like the one I come from are being exploited.”

Sheen even goes to visit some contaminated sites in the series, coming away from one feeling sick. “That made it very real,” he says. “To be looking into a field and going: ‘Well, I’m pretty sure that’s toxic waste.’” Sheen was living a double life of sorts. “I went to rehearsals for a play on Monday and people were like, ‘What did you do this weekend?’” he says. “‘Oh, I went to the most contaminated area in the UK and I think I may be poisoned.’ People thought I was joking.” Sheen ended up being OK, but did have some temporary headaches and nausea, which was a worry. “We literally had to work out if we had poisoned Michael Sheen,” says Ashby, who also ponders in the series: “Have I just killed a national treasure?”

The story gets even knottier. Gowan’s findings turn out to be accurate and prescient, but the narrative around his journey gets muddy. As a character with a flair for drama, he turned his investigation into a juicy, riveting story filled with action, which could not always be corroborated. “If he hadn’t done that, and if he’d been a nerdy, analytical, detail-oriented person who just presented the scientific reports and kept them neatly filed, would we have made this podcast?” asks Taylor, which is a fascinating question that runs through this excellent and gripping series.

Ashby feels that Gowan understood how vital storytelling is when it comes to cutting through the noise. “We have so much science proving the scale of these problems we face and yet we don’t seem to have the stories,” he says. “I think Douglas got that. Fundamentally, he understood that stories motivate human beings to act. But then he went too far.”

However, this is not purely about Gowan’s story – it’s about evidence. The Last Witness doubles up as a groundbreaking investigation into the long-lasting impact of PCBs. “We threw the kitchen sink at this,” says Ashby. “The breakthrough for us is that the Royal Society of Chemistry came on board and funded incredibly expensive testing. So we have this commitment to go after the truth in a way that is hardly ever done.”

From shop-bought fish so toxic that it breaches official health advice to off-the-scale levels of banned chemicals found in British soil, the results are staggering. “The scientist almost fell off his chair,” says Ashby. “That reading is the highest he has ever recorded in soil – in the world. That was the moment we knew Douglas was right and we are now realising the scale of this problem. The public doesn’t realise that even a chemical that has been banned for 40 years is still really present in our environment.”

To go even deeper into just how far PCBs have got into our environment and food chain, Ashby and Taylor had their own blood tested. When Taylor found 80 different types of toxic PCB chemicals in her blood it was a sobering moment. “I was genuinely emotional because it’s so personal,” she says. “It was the thought of this thing being in me that was banned before I was even born and the thought of passing that on to my children.” Ashby adds: “We’ve managed physical risk in our life as journalists in Tanzania and with organised crime, but more scary than a gangster is this invisible threat to our health.”

In order to gauge the magnitude of what overexposure to PCBs can do, they headed to Anniston, Alabama, once home to a Monsanto factory. “As a journalist, you have an inbuilt scepticism and think it can’t be that bad,” says Ashby. “But when I got there I couldn’t believe what I was seeing. I hate to use words like dystopian, but it was. There is a whole massive school that can’t be used. There’s illnesses in children and cancers. It truly was the most powerful vignette of the worst-case example of these chemicals.”

It’s bleak stuff but instilling fear and panic is not the intention. “Obviously, we’re really concerned about it,” says Ashby. “And although the environmental crises we face do feel overwhelming, it is incredible how a movement has formed and how individuals are taking action in communities. The lesson to take from Douglas is that the response doesn’t have to be resignation. It can be agency.”

• Buried: The Last Witness is available on BBC Sounds now.