Levels of toxic ‘forever chemicals’ in some UK fish are 26 times higher than European safety standards. Information gathered by the recently formed Watershed Investigations, reveals that three species of fish in UK waters: dab, flounder and plaice, were found to be heavily contaminated with PFAS chemicals (per- and polyfluorinated alkyl substances).
The European Food Safety Authority sets a recommended maximum weekly exposure to the sum of four specific PFAS chemicals, of 4.4 nanograms per kilogram of bodyweight. They stated in their December 2022 regulation that, “Maximum levels in food for those substances should therefore be set to ensure a high level of human health protection”.
An end to fish and chip Friday?
The Centre for Environment, Fisheries and Aquacultures Science (Cefas) obtained 53 samples from flounder, dab and plaice from around the country, with high pollution levels being found in the Thames, Wash, Mersey, Tees and Wyre rivers. Around 30 types of PFAS were catalogued, including the regulated PFOA and PFOS. More research and data from a wider range of species and a greater sample size could be the next step for researchers.
Many samples obtained exceeded the European safety allowance, with significantly high concentrations of 52.1 micrograms and 42.6 micrograms per kilogram of wet weight of flounder being found in the Thames. Merseyside and Teeside also recorded readings of 11.5 and 1.87 micrograms per kilogram of wet weight of dab respectively.
It is difficult to grasp the importance of this increased factor of a thousand between nanograms and micrograms, which is why the example has been cited in the media of an individual eating contaminated fish twice a year: “a 12 stone (75 kg) adult who eats a 0.4 pound (170 g) portion of this fish more than once every five months would exceed the safe PFAS threshold set by the EFSA.”
Fish and chip Fridays could come to an end, with consumers wishing to reduce their exposure to PFAS chemicals.
Ban PFAS as a class
The UK has no set of guidelines as yet, leaving significant gaps in consumer protection, with scientists concerned that the UK is now lagging behind Europe in combatting the risks posed by these ‘forever chemicals’. The UK currently regulates PFOA and PFOS though there is growing pressure to regulate PFAS as a class, in order to ensure consumer protection in a more timely manner.
A Defra group spokesperson commented on Defra’s support for a ban on specific PFAS chemicals, but did not call for PFAS to be banned as a class:
“Since the 2000s, we have taken action to increase monitoring and support a ban or highly restrict specific PFAS both domestically and internationally.”
Dangers of PFAS
As reported previously by Yorkshire Bylines, per and polyfluorinated alkyl substances are a group of 10,000 industrial chemicals, many of which are linked to major environmental and human health concerns, including liver damage, thyroid disease, testicular cancer and reduced response to vaccines. They have been found to be in consumer packaging in the UK and in drinking water in the UK.
PFAS chemicals are sometimes known as ‘forever chemicals’ as they do not break down in the environment. All PFAS chemicals are persistent and some are toxic and bio accumulative.
PFAS pollution has spiralled out of control
Dr Julie Schneider, PFAS campaigner at CHEM Trust said:
“The more we learn about the harmful properties of PFAS, the more concerned we become. This is why authorities around the world are consistently bringing in more protective safety standards based on the most up to date science.
“PFAS pollution has been left to spiral out of control and it is not acceptable that the most persistent synthetic chemicals ever created are still allowed to be used so widely in our society.”
Dr Schneider added, “The government must urgently turn off the PFAS tap to protect nature and our communities. And a good place to start would be to ban the use of PFAS in cosmetics, consumer textiles and food packaging. A sandwich bag does not need to be coated with PFAS”.

As can be seen in the above mapping of concentration levels of PFAS detected in UK rivers conducted by the Rivers Trust and Wildlife and Countryside Link, there are many hotspots where rivers were revealed to have ten times or more PFAS than the proposed EU safe thresholds. With the environmental quality standards being breached so regularly, the inherent danger is of fish and wildlife ingesting the chemicals, which then travel up the food chain.
The above combined study also revealed that at least 77% of English rivers where forever chemicals have been found would fail proposed new EU safety standards for surface waters. Almost half (44 out of 105 sites) exceeded the proposed new standards by more than five times.
The tip of the chemical iceberg
Dr Janine Gray, head of science and policy at charity WildFish, said:
“The significant concentrations of PFAS found in fish is very concerning but not surprising, and unfortunately just the tip of the chemical iceberg.
“Today, more than 350,000 regulated chemicals are in use. Our waters and their wildlife are exposed to a wide range of these, yet our rivers are currently only routinely checked for 45.
“We must ban all but the most vital uses of PFAS forever chemicals and policy must account for the additive/synergistic effects of chemical mixtures on aquatic life.”
Turning off the PFAS tap
As Dr Julie Schneider highlighted, turning off the PFAS tap remains the number one priority to avoid further pollution and contamination.
“Because the current level of environmental contamination is mostly irreversible. It is not possible to remove PFAS from inside the fish, nor filter out entire rivers, and the PFAS in the environment will only degrade extremely slowly – even more slowly than most plastic litter pieces.
“We must urgently turn off the PFAS tap to stop adding to this environmental PFAS pollution burden. Any additional emissions will increase this burden, elevating the level of background contamination current and future generations will have to deal with and increasing the risk of triggering large scale irreversible adverse effects. Any PFAS use contributes to PFAS emissions, which is why the PFAS tap must be turned off by phasing out all PFAS production and use.
“The end goal must be nothing less than achieving a PFAS-free economy in the next decade.”
Professor of environmental science at York University, Alistair Boxall, also emphasised the importance of the longevity of PFAS chemicals, stressing that understanding the extent of the problem was essential. He told Yorkshire Bylines:
“It will be an enormous challenge to solve the problem. Even if we phased out these chemicals today, the fact they are almost everywhere including in our homes, landfill sites, in soils that have received sewage sludge and aquifers around airports means that they will continue to enter rivers and food for many years to come.
“As this is such a diffuse problem, before we can minimise human exposure, we need to know much more about levels of all of these compounds in fish, crops, meat and drinking water in the UK.
“The big lesson from all of this, is that as a society we need to be much more careful in the future in the use of very persistent chemicals like the PFAS family.”
It’s worth remembering that absence of evidence is not evidence of absence and more research into a greater variety of fish species, as well as rivers, could reveal the real picture and level of PFAS pollution across the UK.







