Susan Smith, who worked at Monsanto in Wrexham, said her happy memories of working there have been replaced with fears following the documentary.

Susan and her husband Geraint’s home, which they have lived in for 53 years, is separated from the decommissioned Ruabon chemical works by a thin tree line.

Geraint was diagnosed with prostate cancer 13 years ago before more recently developing skin cancer, while Susan developed breast cancer when she was 38.

While they admit they are not certain that Monsanto was responsible, the documentary has made them question the possible impact of the factory on their family’s health.

Susan worked as a secretary for four years when she was 19, then returned once for temporary cover and another time to overhaul a failing system.

“Most of my time was spent in the telex office next to the warehouse. We used to send delivery notes, instructions, requests on little pieces of ticker tape through a machine to other Monsanto offices,” she said.

“We had a small glass hatch that the instructions would be passed through and it was never closed because people were passing things through so often. As a result dust and powders and all sorts would blow through and coat the desks, the paper, even our sandwiches.”

Susan said she wasn’t given a “safety briefing, protective clothing or anything” and office staff never knew they were at risk.

Susan had her blood tested by the documentary team and while the PCB levels in her blood were not deemed high, the fact there is no safe level of PCB and the lack of accountability from Eastman – the US company which now owns what was once Monsanto – has left her with unanswered questions.

The couple have joined the Monsanto Contamination Action Group – which was set up for people in Wrexham who live in communities affected by historic industrial waste dumping.

Eastman was approached for comment.

Additional reporting Alec Doyle, LDRS reporter