A new study has reveals the degree to which per- and polyfluoroalkyl substances (PFAS) proliferate throughout the Solent’s marine food web.
In their most wide-ranging investigation yet into PFAS in the stretch of water between Portsmouth and the Isle of Wight, a team from the University of Portsmouth and the Marine Conservation Society, found ‘forever chemicals’ in everything from seaweed and crabs, to fish and harbour porpoises, prompting them to warn that current laws are failing to protect the environment or public health.
Surface water, sediments and treated wastewater were analysed, along with a wide range of marine life. Levels of one of the most tightly regulated compounds – PFOS – exceeded UK and EU legal safety limits 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. The study also mapped 194 combined sewer overflow outfall points and 546 historic landfill sites near the Solent, highlighting the scale of potential sources feeding PFAs into the coastal system.
Among marine wildlife, harbour porpoises showed the highest concentrations, with liver levels far exceeding regulatory ecological thresholds. Levels in fish, invertebrates and seaweeds were mostly within legal boundaries when judged against individual compound limits.
However, when researchers applied a more comprehensive approach by adding up the combined effect of all detected forever chemicals, the picture changed significantly. The majority of species sampled exceeded a European Food Safety Authority health benchmark, suggesting that looking at chemicals one at a time misses the bigger picture.
Professor Alex Ford from the University of Portsmouth’s Institute of Marine Sciences said: ‘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.’
Dr Henry Obanya, lead author and postdoctoral researcher at Portsmouth, added: ‘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. The Solent is an internationally protected area with enormous ecological value, and it deserves the most robust chemical monitoring we can offer.’
A Parliamentary inquiry into PFAS risks is currently underway, with oral evidence sessions continuing into 2026.