Effects of Rock Dust Particles on Airway Mucus Viscosity

Limestone can absorb heat thermal energy from heated gases and release carbon dioxide that has been applied in mines to prevent coal dust explosions. However, the effect of various rock dust particles on altering mucin exocytosis and its rheological properties, leading to concomitant pathological responses, is still unclear. Our research investigated the difference among common rock dusts used in the industry (unmodified limestone (UCRD) and surface modified limestone (MTRD)), their effects on mucin swelling kinetics and airway mucin viscoelastic properties of A549 cells. Our data showed no obvious cytotoxicity on A549 cells with modified and unmodified dust particle exposures. MTRD (modified particles) also demonstrate less harmful effects with less calcium leaching out and cause less disturbance on mucus viscosity compared with UCRD (unmodified particles). Based on the results obtained from this study, modified dust particles provide a better possibility with less interference with airway mucus viscosity and clearance. These findings will provide much needed knowledge and understanding to establish the selection criteria/consideration of rock dusts for the coal industry practical applications.