'Forever chemicals' found throughout Solent food web as researchers call for stronger regulation

Current laws are not doing enough to protect the environment or public health against toxic per- and polyfluoroalkyl substances (PFAS), warns a new study. 

PFAS are a family of nearly 15,000 synthetic chemicals used in everyday products since the 1950s, from non-stick cookware and waterproof clothing to firefighting foam. Because they are extremely resistant to breaking down, they build up in the environment and in living organisms, earning their nickname 'forever chemicals'.  

New research, the latest in an ongoing partnership between the University of Portsmouth and the Marine Conservation Society tested for PFAS in the Solent, a stretch of water between Portsmouth and the Isle of Wight. 

The team analysed a combination of newly collected samples and existing monitoring data. They examined surface water, sediments, treated wastewater, and a wide range of marine life, from seaweeds and crabs to fish and harbour porpoises. 

They found PFAS are present throughout the Solent at multiple levels of the marine environment. Levels of one of the most tightly regulated compounds - PFOS - exceeded the UK and EU legal safety limit for coastal waters by more than thirteen times at the sampling sites tested. 

Two local wastewater treatment plants - Budds Farm in Portsmouth and Peel Common in Fareham, which together serve around 650,000 people - were found to be releasing a wide range of PFAS into the environment in their treated effluents. 

Professor Alex Ford from the University of Portsmouth’s Institute of Marine Sciences, said: “We are seeing chemicals throughout the Solent's food web, from the base right up to marine mammals. Current treatment processes are not designed to remove these substances effectively.” 

The study also mapped around 194 combined sewer overflow (CSO) outfall points and 546 historic landfill sites in close proximity to the Solent, highlighting the scale of potential sources feeding PFAS into the coastal system. 

Among the marine wildlife tested, harbour porpoises showed the highest PFAS concentrations, with levels in liver tissue far exceeding the regulatory ecological threshold. Levels in fish, invertebrates, seaweeds, and other species were lower and, when judged against individual compound limits, mostly within legal boundaries. 

However, when the researchers applied a more comprehensive approach - adding up the combined effect of all forever chemicals detected and expressing them as a single toxicity measure - the picture changed significantly.  

Using this method, the majority of species sampled exceeded a European Food Safety Authority health benchmark, suggesting that looking at chemicals one at a time may be missing the bigger picture. 

Professor Ford added: “We are seeing forever chemicals throughout the Solent's food web, from the base right up to marine mammals. Most species fall within the legal limits when you look at individual chemicals in isolation, but when you consider everything together, the picture is more concerning. Regulation needs to catch up with the science and treat these chemicals as mixtures, not just individual substances. 

“Some of our whales and dolphins are still suffering from chemical contaminants we were slow to ban decades ago. We owe it to future generations to act faster this time.” 

PFAS have been linked to immune system disruption, liver damage and certain cancers in both humans and wildlife. 

Dr Henry Obanya, post doctoral researcher at the University of Portsmouth and lead author of the study, said: “What struck me was just how widespread PFAS contamination is - it's not confined to one part of the food web or one area of the Solent. We found these chemicals in seaweeds, in invertebrates, in fish, and in marine mammals. The Solent is an internationally protected area with enormous ecological value, and it deserves the most robust chemical monitoring we can offer.” 

The new findings come at a time of increasing political and regulatory attention on PFAS in the UK. An earlier study by the same team - focusing on PFAS in Langstone Harbour before and after sewage discharges - was cited in Parliament in November 2024, when Liberal Democrat MP Munira Wilson introduced a Private Member's Bill calling for statutory limits on PFAS in drinking water.  

The previous paper has since been referenced in three separate policy documents, underlining its growing influence on the national policy debate. 

Dr Francesca Ginley, Chemicals Policy and Advocacy Manager at the Marine Conservation Society, said: “This research builds a clearer picture of how PFAS are moving through our seas, reinforcing why we are calling for an urgent, universal PFAS restriction. The only way to tackle this contamination is at its source. The UK Government must act now to protect our marine environment, the wildlife within it, and ultimately all of us who depend on healthy seas. The evidence is clear, now policymakers need to act.” 

The UK currently has no statutory limit on PFAS in drinking water in England and Wales, though the Drinking Water Inspectorate issued updated guidance to water companies in March 2025 requiring them to monitor a wider set of PFAS.  

A Parliamentary inquiry into PFAS risks is also underway, with oral evidence sessions continuing into 2026. Meanwhile, the EU is progressing towards a broad restriction on PFAS across thousands of product categories, and long-chain PFAS were added to the global Stockholm Convention in May 2025, with a worldwide ban set to take effect in December 2026.