A new report says man-made “forever chemicals” are more common in U.S. drinking water supplies than earlier estimates suggested. An environmental group reported Wednesday that some of the highest levels were measured in three big cities. They are Miami, Florida; Philadelphia, Pennsylvania; and New Orleans, Louisiana. “Forever chemicals,” known as PFAS, resist breaking down in the environment. They have possible links to cancer, liver damage and other health problems. The findings of the Environmental Working Group, or EWG, show its 2018 estimate could be far too low. That estimate suggested that 110 million Americans could be contaminated with PFAS.