Some top US lobbying firms are simultaneously working both sides of the Pfas "forever chemicals" issue, raising serious conflict of interest questions and concerns that their activity is slowing states' efforts to rein in the public health threat. The review of six states' lobbying records conducted by the non-profit F-Minus found a range of scenarios in which firms lobbied both sides. Most common Pfas are linked to cancer. The lobbying firm Holland & Knight works for the American Chemistry Council, which represents the nation's largest Pfas makers, and aggressively opposes most regulations. Simultaneously, Holland & Knight lobbies for the American Cancer Society. The review found 26 healthcare systems, 11 public school systems, 15 wildlife groups and 132 local governments that share lobbying firms with Pfas makers or trade groups, including the American Chemistry Council and Cookware Sustainability Alliance. The lobbyists work across 36 states. The report comes amid a broad effort at all levels of the government that aims to rein in Pfas pollution and exposures. The chemicals are widely used in consumer goods and industry, and are linked to a range of health problems like cancer, birth defects, decreased immunity, kidney disease and hormone disruption. The public health effort has drawn an intense lobbying operation in opposition by the chemical industry, which has killed most Pfas legislation in recent years.