Toxic waste sites exposed in Michael Sheen documentary are ‘tip of the iceberg’
BBC/Wall to Wall
A former Monsanto worker speaks out
By Rowenna Hoskin, BBC Wales
Published 25 August 2026
A former Monsanto worker has revealed the dangers he faced while sealing toxic waste underground, stating that staff were provided with "cheap" protective equipment and not informed about the contents they were burying.
Stephen Constance, who worked at the chemical giant’s Newport factory in the 1990s, came forward following the BBC documentary Buried with Michael Sheen, which highlighted Wales’ toxic waste legacy.
While 14 sites featured in the program are just the "tip of the iceberg", according to scientist Dr David Megson, involved in the documentary, there are approximately 20,000 high-concern sites across the UK.
Eastman Chemical Company, responsible for Monsanto’s legacy production in the UK, did not respond to a request for comment.
Constance was one of numerous individuals who contacted BBC Wales after the coverage of Sheen’s investigation into Monsanto and the dumping of polychlorinated biphenyls (PCBs).
A 50-year fight for recognition
Douglas Gowan, a researcher and whistleblower, spent 50 years attempting to convince authorities about widespread dumping of industrial chemicals in Wales, including PCBs, which he termed "some of the worst contaminants known to man." These chemicals were used in various products, such as lipstick and white goods, during the 20th century. They were banned in the UK in the 1970s and subsequently by 151 countries.
Constance, now 61, described his experience at Monsanto as "absolutely dreadful." Reflecting on his time there, he stated, "It was quite evident that nobody was fully appraised of the potential hazard that they were exposed to."
His role involved digging a 6-meter-deep trench around a contaminated mound before sealing it with plastic membrane sheets and liquid clay. While he believes this prevented airborne contamination, he raises concerns about potential ground water contamination due to the high water table influenced by tides.
When asked about his safety, Constance admitted, "In terms of what we knew was there and what we were potentially exposed to, no." He also disclosed that he is in remission from follicular lymphoma, though he does not attribute it to his work at Monsanto.
The documentary uncovers a 1972 memo from Monsanto, which acknowledged the dangers of PCBs to human health, leading to the closure of a site in the US. Interestingly, the company then intensified its operations at the Newport plant.
Dan Ashby and Lucy Taylor, journalists involved in the documentary, highlighted a memo revealing Monsanto’s knowledge of PCB dangers and their subsequent decision to increase operations in Newport despite government assurances that no restrictions would be placed on PCB imports.
