Sign into an existing account

"What Hansen didn’t know was that 3M had already conducted animal studies — two decades earlier. They had shown PFOS to be toxic, yet the results remained secret, even to many at the company. In one early experiment, conducted in the late ’70s, a group of 3M scientists fed PFOS to rats on a daily basis. Starting at the second-lowest dose that the scientists tested, about 10 milligrams for every kilogram of body weight, the rats showed signs of possible harm to their livers, and half of them died."