The most The common lung diseases are.
Such people should try and stay in clean environment and not smoke. I have personalty seen lung disease in few people which such nail formation.
There is no guarantee that such people will always have lung related ailments. It just shows tendencies. Some people just have tendencies and never catch a disease and some acquire a disease due to wrong lifestyle When one breathe, the lungs take in oxygen from the air and deliver it to the bloodstream. The cells in ones body catches oxygen which is inhaled