Michael Sheen investigates Wales' toxic legacy in a new BBC iPlayer documentary
Michael Phillips spent his childhood in the 1980s playing with friends at a lagoon, firing air guns at rusty barrels that released clouds of coloured powder – completely oblivious to the toxic chemicals within.
Decades later, several of those friends and Phillips himself have developed rare cancers, which they believe may be linked to this.
Researcher and whistleblower Douglas Gowan tried to raise the alarm about 14 such sites – 12 of which were in Wales – but died before his warnings were heeded.
"What he told me made my blood run cold," said Hollywood actor Michael Sheen, who spoke to Gowan just months before he died and has now continued his investigation in a new BBC iPlayer documentary.
Gowan, a former farming consultant, alleged that chemical giant Monsanto had dumped "huge amounts of industrial chemicals all around Wales".
These included polychlorinated biphenyls (PCBs), he said, which he described as "some of the worst contaminants known to man" and were widely used during the last century, including for lipsticks and white goods.
"This stuff builds up in the environment, builds up in animals and fish, and it builds up in us," Gowan said.
Eastman Chemical Company, which is responsible for Monsanto's legacy production in the UK, did not respond to either Sheen and his team or the BBC when asked to comment.
Douglas Gowan spent half a century trying to make people listen to his concerns about chemical contamination in Wales
Sheen said PCBs were now known as "the godfather of forever chemicals".
He added: "There is something out there in the forest, there is something in our bodies that can turn against us and tear us apart, but it's not like it is in the horror films. It's invisible. It's a silent killer."
These manmade chemicals are stable, resistant to extreme temperatures and pressures and have insulating properties. Because of this they were used in everything from plastics and paint to electrical equipment.
After concerns about toxicity to humans and animals were raised, a series of bans were put in place around the world from the 1970s onwards.
But the chemicals take a long time to break down and have lingered in the environment, particularly in landfill, where they can leach into waterways and then into the sea.
