River

• Huge volumes of toxic and cancer-causing forever chemicals are flowing into the River Mersey in north-west England.
• The recent State of Our Rivers 2024 report from The Rivers Trust found that one of the most concerning groups of synthetic chemicals, per- and polyfluorinated substances (PFAS), contaminates almost every river in England.
• Known as forever chemicals because they can take thousands of years to break down, PFAS persist in the environment and accumulate in living things.
• They threaten ecosystems and human health, not just in the Mersey, but in every industrialised river around the world.

Dilute, disperse and detect

• Most cities, including Liverpool and Manchester, have been built close to rivers and seas, partly to dilute pollution and transport it away.
• Today, enormous volumes of toxic waste are discharged into rivers and seas because dilution reduces chemical concentrations to extremely low or undetectable levels.
• These forever chemicals have been detected almost everywhere we look, including in Antarctica, in whales and polar bears and in rainwater.

A state of flux

• To prevent further PFAS entering our rivers, more needs to be known about how they move into and through river systems.
• As part of our study, we measured this flux.
• Instead of measuring a chemical’s concentration, flux is a measure of how much PFAS, for example in kilograms per year, flows off the land and out to sea.

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Patrick Byrne receives funding from the UKRI Natural Environment Research Council.