BOSTON: Boston firefighter Daniel Ranahan had heard about colleagues getting cancer but he was stunned when doctors discovered a large tumor in his chest. He was only 30 and had been in the Boston Fire Department less than a decade. But as he investigated his diagnosis of Hodgkin's lymphoma in October 2020 and sought successful treatment, he learned he and others wore gear that contained the toxic industrial compound PFAS. "You always hear about the dangers. You just never think it's going be you," said Ranahan, who stopped...