Simultaneous measurement of mine worker exposure to respirable silica and diesel exhaust participates

CIM Bulletin, Vol. 85, No. 965, 1992

M. Grenier, S. Hardcastle, CANMET, Elliot Lake Laboratory, Elliot Lake, Ontario, D. Mchaina, Dickenson Mines Ltd., Balmertown, Ontario, and M. Gangal, CANMET, Canadian Explosive Atmospheres Laboratory, Bells Corners, Ontario

Exposure to airborne respirable silica in surface and underground mine operations is known to be the cause of industrial lung diseases. For this reason, silica is a regulated substance and worker exposure must be monitored regularly. Diesel exhaust also contains substances which are potential caricinogens. In an underground setting, diesel particulate may be the main component of what is referred to as respirable combustible dust (RCD). Although diesel particulate or soot is not at present a rigorously regulated substance, new epidemiological data is prompting North American institutes and agencies to regulate diesel soot or RCD exposure. This paper describes a method whereby silica and RCD exposure may be determined using a single personal sample. In this method, an airborne respirable dust sample is obtained and analyzed non-destructively for silica components using an on-filter X-ray diffraction method. Filters are then ashed at 500°C in a muffle furnace over a four-hour period to determine mass loss due to RCD burning.