Silica exposure in a mining exploration operation.

BACKGROUND: Though there is extensive research on occupational exposure in production mines, there is limited information on exposure during the exploration phase of mining.

METHODS: Air samples were collected in a core processing facility in Northern Ontario, Canada. All samples were analyzed for respirable dust (NIOSH 0600) and respirable crystalline silica (NIOSH 7602). Mean exposure levels were estimated and differences in exposure between work areas were investigated.

RESULTS: Sixteen personal and nine area air samples were collected. Respirable dust exposure ranged from < LOD to 2.24mg-m-3 ; respirable silica exposure ranged from < LOD to 0.055mg-m-3 . Silica concentrations were higher among workers in the core cutting and core sorting (pulp and reject) areas, as compared to those in the core logging area.

CONCLUSIONS: Workers employed in core processing facilities as part of mining exploration activities are exposed to respirable silica; exposure controls may be needed.