Many N.F.L. Players Get Brain Disease. Why Hasn’t OSHA Intervened?

“We never see things that are this dire,” a former chief scientist of the agency said about rates of C.T.E. in former players.The former N.F.L. player Jonathan Martin entering an M.R.I. machine for a brain examination that was part of a study to develop treatments for the symptoms and illnesses linked to C.T.E.