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. Gowan, a former farming consultant, alleged that chemical giant Monsanto had dumped "huge amounts of industrial chemicals all around Wales". "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.