Mineral Particles in Airway Walls in the Lungs of Long-Term Chrysotile Miners

Abstract

In order to investigate the relationship of pathological lesions in small airways to local mineral burden, we analysed the particles/area in the walls of 99 membranous bronchioles (MB, roughly Weibel generations 9–16) and 100 respiratory bronchioles (RB, roughly Weibel generations 17–20) from the lungs of 20 long term chrysotile miners. Electron optical techniques were used to identify and count particles in plastic embedded sections; airways were also graded for amount of fibrosis. We found that RB had significantly higher particle concentrations as well as larger particles than MB, and that MB and RB with greater degrees of fibrosis had higher particle concentrations than those with lesser degrees of fibrosis. We conclude that more distal airways (RB) are subject to greater long-term particle burdens than more proximal airways (MB), and that mineral particle burden correlates with airway wall fibrosis.