Levels of two toxic “forever” chemicals in English rivers have fallen by nearly a third over the last decade, according to new Environment Agency figures released Thursday.
The concentrations of PFOS and PFOA have declined significantly due to stricter product restrictions implemented after evidence linked the substances to environmental damage and human health issues. While these specific legacy chemicals are decreasing, the Environment Agency said that thousands of other PFAS compounds remain in use, necessitating improved monitoring and regulation.
The Environment Agency report shows that concentrations of PFOS in English rivers fell by approximately 30 percent between 2016 and 2025. During the same period, PFOA levels in those rivers dropped by 29 percent.
The decline follows targeted regulatory actions in the UK. PFOS was all but banned in the country in 2010, while PFOA was restricted in 2020. Researchers previously identified links between these chemicals and increased rates of certain serious health conditions, such as testicular cancer, as well as tissue damage in animals.
The reduction in chemical presence extends to the local food chain. Levels of PFOS found in freshwater fish have fallen by 49 percent.
| Chemical / Indicator | Percentage Change (2016–2025) |
|---|---|
| PFOS in English rivers | 30% decrease |
| PFOA in English rivers | 29% decrease |
| PFOS in freshwater fish | 49% decrease |
Despite the downward trend in specific legacy chemicals, the Environment Agency warned that the overall amount of PFAS in the environment may remain unchanged because the substances take a very long time to break down. The regulator suggested that the chemicals have essentially been diluted and washed into the sea.
The findings will assist in the delivery of the UK’s first PFAS Plan, a government strategy published earlier this year to manage the spread and exposure of these persistent substances. The plan includes steps to improve testing in coastal waters and estuaries, and to develop safer alternatives for products like water-repellent clothing.
The Environment Agency is currently testing for 60 other PFAS to map national contamination. The government also announced earlier this month that it would begin monitoring levels of these chemicals in human bodies.