Concentrations of two toxic “forever chemicals” in England’s rivers have fallen by nearly a third over the last decade, according to new figures from the Environment Agency.
The report, PFAS sources, pathways and environmental data (2026), published on Thursday, attributes these declines to stricter regulations on the use of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). Between 2016 and 2025, concentrations of PFOS in English rivers dropped by about 30 percent, while PFOA levels fell by 29 percent.
Levels of PFOS in freshwater fish tissue also declined by around 49 percent over a similar period.
Stricter Rules Cut River Toxins
The reduction in these substances follows national restrictions on their use. PFOS was all but banned in the UK in 2010. A ban on PFOA followed in 2020.
The Environment Agency said these chemicals, officially known as per- and polyfluoroalkyl substances (PFAS), were historically popular in products ranging from non-stick cookware to firefighting foams due to their water- and oil-resistant properties.
It’s brilliant to see how far we have come in the last 10 years.
Dr David Megson, reader in environmental forensics at Manchester Metropolitan University
Despite the decline in legacy chemicals, the regulator warned that PFAS contamination remains widespread. The report said its findings reinforce the need for regulating all PFAS rather than one by one.
Regulators Monitor New Substances
The regulator is now regularly testing for 60 other PFAS to build a picture of contamination across the country.
Our understanding of PFAS has advanced significantly since 2021, with the agency now able to monitor a much wider range of the chemicals with greater accuracy.
Dr Robert Bradburne, the Environment Agency’s chief scientist
Government Plans Future Policy
The findings will support the delivery of the UK’s PFAS Plan. The Government published the plan earlier this year to better protect the nation and environment from these persistent chemicals.
The plan sets out future direction to understand where these chemicals come from, how they spread and how to reduce exposure to them.
“I welcome the findings of this report, and this government is determined to reduce exposure to these chemicals for the public and the environment,” said Minister Emma Hardy.
The government is considering a possible restriction on the use of forever chemicals in firefighting foams, and legislating to prohibit further persistent organic pollutants. One of the few ways to permanently destroy PFAS is by high-temperature incineration. There are just two such suitable sites in the country.
Earlier coverage: Environment Agency Reports 30 Percent Drop in Toxic 'Forever' Chemicals in English Rivers