RT @drdavidliew: Coal mining is associated with developing RA, but what is it about it? It's the silica. The more silic

Coal mining is associated with developing RA, but what is it about it? It's the silica. The more silica and the longer exposed, the more likely. Hopefully, one day, we'll get be able to prevent this... @UCSFMedicine @UCSFRheum #ACR20 ABST1462 @RheumNow https://t.co/mlZNpJD9iv