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Besides quartz and asbestos, less is known about the potential health effects of other mineral particles. This randomized, double-blind crossover study, including 24 healthy non-smoking volunteers, showed that the stone aggregate quartz diorite triggers pulmonary inflammation after short-term exposure. The stone aggregate rhomb porphyry was associated with a modest but statistically significant decline in lung function.

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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.

Occupational exposure concentrations are routinely collected using gravimetric samples. However, gravimetric samples typically require a long sampling time, especially when there are low exposure concentrations. While long sampling time may be appropriate to verify compliance with 8-h occupational limit values (OELs), they cannot address exposure's temporal and spatial heterogeneity or provide information on peak exposures present in the work environment. Real-time light scattering sensors enable the possibility of collecting high-resolution, low-cost measurements, quickly identifying peak and short-term concentrations, linking exposure to emission sources, and better understanding within-day variation. These technologies have become increasingly popular also for occupational monitoring purposes. In this presentation, the results of the dust samples collected for a randomized double-blinded controlled human exposure chamber study are presented. In six groups, 24 healthy volunteers were exposed to two common stone minerals, quartz diorite, and rhomb porphyry, in 4-h exposure sessions. To control the exposure in the chamber, personal gravimetric samples of respirable dust and stationary gravimetric samples of total dust, PM2.5, and respiratory dust were collected. Additionally, stationary real-time samples of total dust, respirable dust, PM10, PM2.5, and PM1 were collected continuously using DustTrak TSI model DRX 8533. Despite the many advantages of the real-time sensors, evaluating compliance with OELs should be done with caution. Except for the PM2.5 fraction, a significant difference was observed between the gravimetric and the DustTrak samples. While the DustTrak overestimated the PM2.5 concentrations, the total dust concatenations were underestimated by a factor of almost two compared to the gravimetric samples.