A new Environment Agency report shows significant reductions in two harmful PFAS chemicals over the past decade, although widespread contamination and newer substances remain serious concerns.
Levels of two harmful chemicals known as PFOS and PFOA have fallen by nearly 30% in England’s rivers over the past decade, according to an Environment Agency report released Thursday, November 12, 2026. The findings suggest that restrictions on these persistent pollutants are producing measurable improvements, although thousands of related chemicals remain an environmental concern.
The government report found that PFOS concentrations in English rivers declined by approximately 30% between 2016 and 2025. Levels of PFOA fell by 29% over the same period, while PFOS concentrations in freshwater fish dropped by an estimated 49% between 2016 and 2024.
Scientists welcomed the progress but warned that declining concentrations do not mean the chemicals have disappeared. Many substances in the PFAS family remain in use, and pollution accumulated over decades continues to affect rivers, wildlife and other parts of the environment.
England’s Rivers Show Significant Declines in PFAS Pollution
The Environment Agency’s latest assessment examined the sources, movement and concentrations of per- and polyfluoroalkyl substances, collectively known as PFAS.
These substances are commonly called forever chemicals because many resist natural breakdown and can remain in water, soil and living organisms for extended periods.
PFAS have been used in industrial processes and everyday products for decades. Their resistance to water, oil and heat has made them useful in manufacturing, firefighting equipment, food packaging and certain medical applications.
However, research has linked exposure to some PFAS with serious health concerns, including certain cancers, immune system effects and developmental problems.
PFOS and PFOA are among the most extensively studied members of the chemical family. Their persistence and potential health effects led governments to introduce restrictions intended to reduce their release into the environment.
The United Kingdom largely prohibited PFOS in 2010 and PFOA in 2020, subject to limited exemptions and transitional arrangements.
The latest monitoring results indicate that those controls, together with other measures to limit pollution, have helped reduce concentrations of the two substances.
The reductions were observed across long-term monitoring records rather than through testing at a single location. This provides a broader picture of changes in contamination over time.
Still, the findings do not establish that every river has become cleaner. Some waterways remain affected by pollution from historical industrial activities, wastewater, contaminated land and other sources.
Freshwater Fish Show a 49% Reduction
One of the report’s most encouraging findings involved freshwater fish.
Scientists estimated that PFOS concentrations in sampled freshwater fish declined by approximately 49% between 2016 and 2024. The reduction averaged roughly 7% annually over that period.
Fish can absorb PFAS from contaminated water and food, making them useful indicators of pollution within aquatic ecosystems.
Some PFAS accumulate in animal tissues, particularly when organisms are exposed over extended periods. Their presence in fish therefore provides information that water samples alone cannot capture.
The decline suggests that lower concentrations in rivers are beginning to be reflected in living organisms.
However, the findings relate specifically to PFOS. The agency could not establish an equally reliable long-term trend for PFOA in freshwater fish because many measurements were below the laboratory reporting thresholds.
This distinction matters because different PFAS behave differently in the environment. A decline in one substance does not necessarily mean that all related chemicals are decreasing.
The report also does not establish that freshwater fish throughout England are free from contamination or that eating fish from any particular river is safe.
Such decisions depend on local conditions, the species involved and the concentrations of potentially harmful substances.
Scientist Welcomes Progress but Warns More Work Is Needed
Dr David Megson, a researcher in chemistry and environmental forensics at Manchester Metropolitan University, welcomed the findings.
“It’s brilliant to see how far we have come in the last 10 years,” Megson said in comments published by the Environment Agency.
He emphasized that the expanded monitoring program provides scientists with valuable information about where contamination remains concentrated.
The agency now has access to results from thousands of environmental samples, allowing researchers to examine patterns that would have been difficult to detect through smaller investigations.
Megson said the findings could help authorities identify heavily polluted locations and direct resources toward areas where further intervention would be most effective.
He also welcomed improvements in analytical techniques that allow scientists to investigate a broader range of PFAS, including substances that conventional testing may miss.
These methods could help regulators identify emerging pollution problems before they become more widespread.
Megson stressed that the results provide a foundation for further action, including investigations into responsibility for environmental damage.
Thousands of Forever Chemicals Remain in Use
Despite progress on PFOS and PFOA, scientists face a much larger challenge involving the broader PFAS family.
Estimates suggest that approximately 15,000 PFAS substances have been identified under broad chemical definitions. Their properties, uses and potential health effects vary considerably.
Only a fraction have been studied extensively enough to establish clear conclusions about their toxicity.
Some PFAS can accumulate in the body or environment, while others behave differently depending on their chemical structure.
The Environment Agency has expanded its monitoring capabilities to examine many more substances than were routinely tested in previous years.
Its latest assessment covers rivers, lakes, groundwater, estuaries, coastal waters and liquid waste draining from landfill sites.
The program also examines substances that can break down into other PFAS, potentially creating additional contamination concerns.
This broader approach reflects growing recognition that focusing exclusively on PFOS and PFOA provides an incomplete picture of environmental exposure.
At the same time, regulators must distinguish between substances with established risks and those for which reliable evidence remains limited.
Some PFAS serve important purposes in medical equipment, industrial manufacturing and low-carbon technologies. Replacing them can require developing alternatives that provide similar performance without creating new environmental problems.
Falling Concentrations Do Not Mean Pollution Has Disappeared
The report raises an important distinction between reducing chemical concentrations and removing pollutants from the environment altogether.
PFAS can move through rivers, groundwater and drainage systems. Over time, some contamination may spread into coastal waters rather than being permanently destroyed.
Consequently, falling measurements at individual monitoring locations do not necessarily demonstrate an equivalent reduction in the total amount of pollution across the environment.
Historical contamination also remains difficult to address because many PFAS break down extremely slowly under ordinary environmental conditions.
Treating contaminated water can remove certain substances, but the treatment process may produce concentrated waste that requires careful handling.
High-temperature incineration is one method used to destroy some PFAS under appropriate operating conditions. However, effective destruction depends on the equipment, temperatures and treatment processes involved.
Specialized disposal facilities can be expensive to operate, and capacity for handling heavily contaminated waste remains a concern.
Preventing additional releases is therefore an important part of managing long-term PFAS pollution.
UK Government Expands Monitoring and Regulation
The findings will help guide the United Kingdom’s first national PFAS Plan, published in February 2026.
The strategy sets out measures to improve understanding of where the chemicals originate, how they move through the environment and how human exposure can be reduced.
Among its priorities are stronger monitoring, clearer guidance for businesses and regulators, and support for developing safer alternatives.
The government is also considering additional restrictions on PFAS in firefighting foams, historically an important source of contamination around airports and training facilities.
Environment Minister Emma Hardy said the government was working to strengthen controls and improve environmental protection.
“We are acting to crack down on forever chemicals through tougher rules on their use,” Hardy said in the Environment Agency announcement.
The government also intends to improve monitoring in estuaries and coastal waters and strengthen efforts to address contaminated land.
These measures are designed to supplement existing restrictions rather than replace them.
The agency’s chief scientist, Dr Robert Bradburne, said advances in analytical methods now allow scientists to identify a wider range of chemicals and understand their environmental behavior more accurately.
That information should help regulators decide where additional controls and cleanup measures are most necessary.
What the Findings Mean for Public Health
The reported reductions represent a positive environmental development, but they do not provide a direct measure of changes in human health.
People can encounter PFAS through multiple pathways, including drinking water, food, contaminated soil and certain consumer products.
Exposure risks depend on the particular substance, its concentration, the length of exposure and individual circumstances.
Scientists have established associations between some PFAS and adverse health outcomes, but the evidence is not equally strong for every member of the chemical family.
The latest Environment Agency report focuses primarily on environmental contamination. It does not demonstrate that cancer rates or other health conditions have fallen because PFOS and PFOA concentrations declined.
Nevertheless, reducing the release of persistent chemicals can help limit future exposure and protect aquatic ecosystems.
The Environment Agency will continue expanding its monitoring program and examining emerging substances, including potential replacements for restricted chemicals.
Its latest findings provide evidence that controls on PFOS and PFOA have been followed by substantial environmental improvements. The remaining challenge is understanding and managing the wider PFAS family while addressing pollution already present in England’s waterways.
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