People living near a chemicals plant in Lancashire have been told to wash and peel vegetables from their gardens before eating them, while an investigation into potential contamination of soil in the area with a banned toxic chemical gets under way.

The chemical PFOA, one of the PFAS family of about 15,000 chemicals, does not break down in the environment and last year was categorised as a human carcinogen by the World Health Organization. It is also toxic to reproduction and has been linked to a range of health problems such as thyroid disease and increased cholesterol.

Last year the Guardian and Watershed Investigations revealed that the AGC Chemicals plant in Thornton Cleveleys, near Blackpool, was discharging hundreds of PFAS into the River Wyre, which flows into Morecambe Bay, including very high concentrations of the banned PFOA.