Rémi Camus finds PFAS flowing from the Rhône into the Mediterranean

Forty-eight tonnes of permanent pollutants pour from the Rhône River into the Mediterranean Sea each year, according to scientific sampling published in the research review Water Research on August 26, 2026. Explorer Rémi Camus documented the concentrations after navigating the entire length of the river in a 2025 expedition, establishing that industrial chemicals heavily contaminate the waterway downstream of Lyon.

The Expedition and Sampling Along the Rhône

Rémi Camus spent September and October 2025 traveling from the Swiss source of the Rhône to its mouth in the Bouches-du-Rhône inside an inflatable kayak. The journey yielded 160 distinct water samples analyzed for per- and polyfluoroalkyl substances, commonly known as PFAS or eternal pollutants. tribuneblelyon.fr reported that the explorer found zero traces of PFAS in the two samples taken directly on the glacier. However, trifluoroacetic acid (TFA), a perfluorinated compound facing potential classification as a carcinogen by the European Union, appeared immediately at the glacial lake stage.

Industrial Discharges Downstream of Lyon

The contamination levels shift dramatically as the water reaches urban and industrial sectors. Camus identified a clear rupture point at the Feyssine threshold near Lyon, where chemical signatures absent in the upper reaches of the river suddenly emerge to impact downstream populations. The explorer noted that despite the high concentration of invisible pollutants, the water of the Rhône remains deceptively clear and limpid, complicating public awareness of the hazard. Arkema previously discharged 3.5 tonnes of PFAS annually into the river on its own before enacting significant reductions through new filtration systems.

European Depollution Costs Reach 2,000 Billion Euros

While major industrial actors have implemented filtration to prevent direct discharges, mitigation efforts remain far from complete. Calculations published in Le Monde place the total cost of European depollution over the next twenty years at 2,000 billion euros, excluding the additional challenge of TFA remediation. Camus plans to launch a bicycle tour from the source to the mouth of the Rhône between November 2 and November 13, 2026, presenting a documentary of his descent alongside public conferences, including a scheduled event at the Lyon Maison de l’Environnement on November 7.