By Sandee LaMotte, CNN (CNN) — Key Biden-era regulations designed to protect the nation’s drinking water from the most dangerous cancer-causing per-and polyfluoroalkyl substances, or PFAS, were removed by the Trump administration Monday. Manufactured since the 1940s to make products nonstick, stain-resistant and water-repellent, PFAS chemicals have been linked to cancer, obesity, thyroid disease, high