Comparison of Gravimetric and Optical Measures of Respirable Stone Dust Exposur

Two main devices used to quantify exposure to respirable dust are respirable cyclone samplers and real-time direct-reading dust monitors. Cyclone samplers are currently used as the gold standard of measurement, but real-time direct-reading monitors, such as the TSI SidePak, may potentially provide a fairly accurate measurement of concentrations of respirable dust if the instrument has been calibrated for the aerosol being measured. In this study, controlled experiments were conducted outdoors in an enclosed shelter during various stone manipulation techniques. Abrasive wheel grinding, cup grinding, core drilling, and polishing were used on quartz-rich engineered stone under various conditions. The respirable dust mass concentration calculated for the GK4.162 RASCAL cyclone sampler and average respirable dust mass concentration indicated by the TSI SidePak direct-reading monitor were compared. Data analysis by scatter plot showed non-linearity which disagreed with the hypothesis that mass concentration would be equivalent. Ultimately, it was determined that the TSI SidePak requires appropriate calibration to the type of dust being measured, but even with accurate calibration it may lack the precision for measuring mass concentrations above and below 20 mg/m3 compared to a properly used GK4.162 (RASCAL) respirable cyclone with precise gravimetric analysis.