ahlam1399
07-01-2017, 09:43 PM
Black lung results from exposure to coal dust. Progressive massive fibrosis is an especially aggressive form, blamed on inhalation of silica dust from the cutting of quartz rock and coal together.
أكثر... (http://www.npr.org/sections/thetwo-way/2017/07/01/535082619/npr-continues-to-find-hundreds-of-cases-of-advanced-black-lung?utm_medium=RSS&utm_campaign=news)
أكثر... (http://www.npr.org/sections/thetwo-way/2017/07/01/535082619/npr-continues-to-find-hundreds-of-cases-of-advanced-black-lung?utm_medium=RSS&utm_campaign=news)