Comparing PM2.5, respirable dust, and total dust fractions using real-time and gravimetric samples in a human exposure chamber study

Abstract

Using a human exposure chamber, we investigate the reliability of the DustTrak DXR monitor by comparing its results to those obtained from taking traditional gravimetric samples of two stone minerals commonly used in asphalt and lactose powder. We also discuss the possibility of using real-time monitors such as DustTrak for occupational exposure monitoring purposes. The results are based on 19 days of experiment, each day with measurements collected over 4 h. Compared to the gravimetric samples, the DustTrak overestimated the PM2.5 and respirable dust concentrations, while it underestimated the total dust concentration by a factor of nearly two. However, the ratios, being done for more than one material, between the DustTrak and the gravimetric sample readings varied daily and across the different exposure materials. Real-time sensors have the potential to excel at identifying exposure sources, evaluating the measured control efficiency, visualizing variations in exposure to motivate workers, and contributing to the identification of measures to be implemented to reduce exposure. For total dust, a correction factor of at least two should be used to bring its readings up to those for the corresponding gravimetric samples. Also, if the DustTrak is used in the initial profiling of occupational exposure, the exposure could be considered acceptable if the readings are well below the occupational exposure limit (OELs) after correction. If the DustTrak readings, after correction, is close to, or above, the accepted exposure concentrations, more thorough approaches would be required to validate the exposure.

Measures to reduce carpenters’ occupational exposure to mineral wool fibers and total dust while working indoors in Norway

“…Visualizing the variations in dust concentrations using real-time sensors could be an effective tool for communicating the risks associated with different work tasks (34). If the workers themselves were allowed to identify which tasks need attention, the motivation to spend time on dust-reducing measures would increase.…”