Dangerous levels of “forever chemicals” have infiltrated the soil, water, and marine food chain of the UK’s Solent strait, even within legally protected conservation sites, a new study has revealed.

PFAS (per- and polyfluoroalkyl substances) are a family of nearly 15,000 synthetic chemicals. Ubiquitous in everyday manufacturing since the 1950s, they are found in everything from non-stick cookware and waterproof apparel to firefighting foams. Because these chemicals are virtually indestructible in nature, they accumulate over time within the tissues of marine wildlife, including seabirds and porpoises.

To map the scale of the contamination, researchers analysed government data, public water utility records, and their own field samples across a dozen species of seaweed, fish, and invertebrates. 

Some samples revealed pollution levels 13 times higher than the safe threshold for coastal waters. While other samples technically fell below the legal limits for individual substances, they ultimately failed safety tests due to their combined toxicity.

Among the local wildlife tested, harbour porpoises exhibited the highest concentrations of PFAS, with toxic build-up in their liver tissue far exceeding regulatory ecological safety thresholds. 

Contamination levels in fish, invertebrates, and seaweed were lower and remained largely within legal boundaries when evaluated against single-compound limits.

Researchers traced the source of the Solent’s PFAS pollution to treated effluent discharged from wastewater plants in Portsmouth and Fareham. These facilities are operated by Southern Water, the regional utility responsible for drinking water and sewerage services across Kent, Sussex, Hampshire, and the Isle of Wight.

Professor Alex Ford, from the University of Portsmouth’s Institute of Marine Sciences, said that the chemicals have permeated the Solent’s marine food web.

In response, a spokesperson for Southern Water stated: “Tackling the presence of these chemicals is a challenge for society as a whole.”

Professor Ford agreed that the responsibility extends beyond utility providers, telling The Guardian: “This is one thing I don’t necessarily pin on the water companies because they don’t have the capacity to treat these compounds. That’s why they should be banned at source.”

The research team emphasised that their findings highlight a critical flaw in current regulatory frameworks, arguing that chemicals must be monitored in combination rather than in isolation. They are calling for a comprehensive, blanket ban on PFAS to be integrated into the government’s upcoming water reform agenda.

While DEFRA announced a dedicated PFAS strategy earlier this year, the plan drew criticism from environmental groups for lacking decisive action.

The Marine Conservation Society, which funded the Solent study, urged the government to accelerate its timeline.

Dr Francesca Ginley, the society’s Policy and Advocacy Manager, said: “Restricting their use must be a priority for the UK Government – every day of delay leads to further harm across the entire ecosystem that both nature and people depend on.”

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