Toxic forever chemicals in English rivers drop by nearly a third

Concentrations of PFOS in English rivers have fallen by 30% over the past ten years, and PFOA by 29%, according to Environment Agency data published on Thursday. Levels in freshwater fish dropped even further, down 49%. The regulator credits tighter restrictions on the chemicals' use as evidence piled up about their damage to human health and the environment.

The two compounds were the earliest forms of PFAS, the family first developed in the 1930s in the US and prized by manufacturers of frying pans and firefighting foam for being oil-resistant, water-resistant and electrically useful. Their natural stubbornness is the problem: they break down so slowly they earned the nickname forever chemicals. Two decades ago researchers linked them to tissue damage in animals and higher rates of serious conditions including testicular cancer, prompting the UK to all but ban PFOS in 2010 and PFOA in 2020.

"It's brilliant to see how far we have come in the last 10 years," said Dr David Megson, a reader in environmental forensics at Manchester Metropolitan University. He added that the report gives an "essential foundation to support investigations to make the polluters pay for any damage they have caused."

The agency isn't declaring victory. It said uncertainty remains over the toxicity of many PFAS, and that its findings reinforce the case for regulating them as a group rather than one at a time. Roughly 15,000 other PFAS exist, though only about 200 are used often. The chemicals industry has pushed back for years, arguing there is little or no evidence other PFAS are toxic and that some are vital to life-saving medical equipment.

Falling concentrations don't mean the chemicals are gone. The EA report acknowledged that because PFAS take so long to degrade, the overall amount in the environment has likely stayed the same — diluted and washed out to sea rather than destroyed. Permanent destruction basically requires high-temperature incineration, and the country has just two suitable sites. Meanwhile the regulator is routinely testing for 60 more PFAS, and earlier this month the government said it would start monitoring levels inside people's bodies.