Table 1

‚ÄÉCategories of silica exposure and smoking habits among silica exposed RA cases and silica exposed controls

Category of silica exposureNumber of exposed cases/controls*Number of smokers among exposed cases/controls*
*Cases and controls may belong to more than one category of silica exposure.
Rock drilling12/610/3
Stone crushing9/59/4
Stone dust (unspecified)33/1830/14
Silica exposure overall41/2037/15