Huge volumes of toxic and cancer-causing forever chemicals are flowing into the River Mersey in north-west England. With a busy, industrialised skyline and both Manchester and Liverpool nearby, it’s the second-most populated river catchment in the UK after the Thames.

None of England’s rivers are in good chemical health. The recent State of Our Rivers 2024 report from The Rivers Trust found that one of the most concerning groups of synthetic chemicals, per- and polyfluorinated substances (PFAS), contaminates almost every river in England.