AdvertisementNPR Continues To Find Hundreds Of Cases Of Advanced Black LungJuly 01, 2017Howard BerkesfacebookEmailSliced sections of lungs show the damage and disease caused by excessive exposure to coal and silica dust. The middle slide depicts a lung with fibrotic tissue resulting from simple coal workers' pneumoconiosis or black lung. The slide on the right shows hardened and blackened lung tissue when black lung disease reaches its most advanced stage. (Courtesy of the National Institute for Occupational Safety and Health)