Forever chemicals have polluted the water supply of 60,000 people, threatening human health, wildlife and the wider ecosystem. But activists say this is just the tip of the Pfas iceberg

One quiet Saturday night, Sandra Wiedemann was curled up on the sofa when a story broke on TV news: the water coming from her tap could be poisoning her. The 36-year-old, who is breastfeeding her six-month-old son Côme, lives in the quiet French commune of Buschwiller in Saint-Louis, near the Swiss city of Basel. Perched on a hill not far from the Swiss and German borders, it feels like a safe place to raise a child – spacious houses are surrounded by manicured gardens, framed by the wild Jura mountains.

But as she watched the news, this safety felt threatened: Wiedemann and her family use tap water every day, for drinking, brushing her teeth, showering, cooking and washing vegetables. Now, she learned that chemicals she had never heard of were lurking in her body, on her skin, potentially harming her son. “I find it scary,” she says. “Even if we stop drinking it we will be exposed to it and we can’t really do anything.”