Michael Sheen Investigates Wales' Toxic Legacy: 'What He Told Me Made My Blood Run Cold'

Hollywood actor Michael Sheen has released a BBC iPlayer documentary investigating what campaigners describe as a catastrophic toxic legacy left across Wales by the chemical industry. The film follows Sheen's investigation into claims that Monsanto and other chemical companies dumped polychlorinated biphenyls (PCBs) at sites across Wales and England, with survivors and bereaved families alleging a link to clusters of rare cancers.

Whistleblower's Warning

The documentary centres on the testimony of Douglas Gowan, a former farming consultant turned researcher who spent decades trying to expose what he alleged were 14 toxic dumping sites — 12 of them in Wales. Gowan, who died before the film was completed, told Sheen that chemical giant Monsanto had disposed of 'huge amounts of industrial chemicals all around Wales', including PCBs. 'What he told me made my blood run cold,' Sheen said. Gowan described PCBs as 'some of the worst contaminants known to man', widely used last century in everything from lipsticks to electrical equipment and white goods, before being banned from the 1970s onwards due to their toxicity.

Michael Phillips and the Lagoon

The film opens with Michael Phillips, who grew up in the 1980s playing at a lagoon where he and friends fired air guns at rusty barrels, releasing clouds of coloured powder. Oblivious to the chemicals inside, they played there regularly. Decades later, Phillips and several of his childhood friends have developed rare cancers. They believe their illnesses may be linked to the site. 'This stuff builds up in the environment, builds up in animals and fish, and it builds up in us,' Gowan told Sheen in footage shot before his death.

PCBs: The 'Godfather of Forever Chemicals'

PCBs are manmade chemicals praised for their stability and insulating properties. Because of this they were used extensively — in plastics, paint, electrical equipment and even cosmetics. After growing evidence of their toxicity to humans and wildlife, bans were introduced around the world from the 1970s. But PCBs are extraordinarily persistent: they resist breakdown, linger in landfill and leach into waterways, eventually building up in the food chain. Sheen described them as the 'godfather of forever chemicals', noting that their effects are 'invisible' and 'silent' — unlike the monsters of horror films, they cause harm without being seen. Eastman Chemical Company, which is responsible for Monsanto's legacy production in the UK, did not respond to requests for comment from either Sheen's team or the BBC.

Calls for Justice

The documentary has prompted renewed calls from Welsh politicians and environmental groups for a formal public inquiry into the sites and the health of communities living near them. Campaigners argue that authorities were warned for years but failed to act. Gowan's family said his dying wish was that the public would finally hear what he had spent half a century trying to say.