Collection Efficiencies of High Flow Rate Personal Respirable Samplers When Measuring Arizona Road Dust and Analysis of Quartz by X-ray Diffraction

Abstract

Prolonged exposure to respirable crystalline silica (RCS) causes silicosis and is also considered a cause of cancer. To meet emerging needs for precise measurements of RCS, from shorter sampling periods (<4h) and lower air concentrations, collaborative work was done to assess the differences between personal respirable samplers at higher flow rates. The performance of FSP10, GK2.69, and CIP 10 R samplers were compared with that of the Safety In Mines Personal Dust Sampler (SIMPEDS) sampler as a reference, which is commonly used in the UK for the measurement of RCS. In addition, the performance of the FSP10 and GK 2.69 samplers were compared; at the nominal flow rates recommended by the manufacturers of 10 and 4.2 l · min−1 and with flow rates proposed by the National Institute for Occupational Safety and Health of 11.2 and 4.4 l · min−1. Samplers were exposed to aerosols of ultrafine and medium grades of Arizona road dust (ARD) generated in a calm air chamber. All analyses for RCS in this study were performed at the Health and Safety Laboratory. The difference in flow rates for the GK2.69 is small and does not result in a substantial difference in collection efficiency for the dusts tested, while the performance of the FSP10 at 11.2 l · min−1 was more comparable with samples from the SIMPEDS. Conversely, the GK2.69 collected proportionately more crystalline silica in the respirable dust than other samplers, which then produced RCS results most comparable with the SIMPEDS. The CIP 10 R collected less ultrafine ARD than other samplers, as might be expected based on earlier performance evaluations. The higher flow rate for the FSP10 should be an added advantage for task-specific sampling or when measuring air concentrations less than current occupational exposure limits.

Silica Measurement with High Flow Rate Respirable Size Selective Samplers: A Field Study

“…Performance of high flow rate samplers was previously investigated in laboratory experiments (Lee et al ., 2010, 2012; Stacey et al ., 2014) and the high flow rate samplers (CIP10-R, FSP10, and GK2.69) were shown to meet the performance requirement from the International Organization for Standardization (ISO) with respect to respirable convention sampling (ISO, 1995). The samplers showed <30% difference in mass concentration compared to ideal respirable fraction in accordance with a standard protocol (EN13205, 2002).…”

“…The samplers showed <30% difference in mass concentration compared to ideal respirable fraction in accordance with a standard protocol (EN13205, 2002). Averages of respirable dust mass concentration and quartz mass concentration ratios comparing high and low flow rate samplers from laboratory studies (Lee et al ., 2012; Stacey et al ., 2014) and from the present study are shown in Table 5. Although the average ratios from the laboratory studies are based on arithmetic means with standard deviations and those from the present study are GMs and upper and lower 95% confidence intervals without outliers, the average ratios from the studies are comparable in both respirable dust mass concentration and quartz mass concentration.…”

“…While the average quartz mass concentration from the CIP10-R sampler is significantly larger than that from 10-mm nylon and HD type cyclones (Fig. 4), linear regression analysis showed that the CIP10-R sampler provided significantly lower quartz mass concentration than HD type cyclone (Table 4), which has been observed previously (Stacey and Thorpe, 2009; Stacey et al ., 2013; Verpaele and Jouret 2013; Stacey et al ., 2014). …”

“…inhalable, thoracic, or respirable, there are other important issues including cost of sampling, worker acceptance (comfort and placement of sampling device) and industrial hygienist concerns (ease of calibration and sample analysis; for example, the jar necessary for calibration of the 10-mm nylon cyclone is cumbersome in the field). The FSP10 cyclone has been calibrated to provide a respirable sample at 11.2 l min −1 , which would provide adequate sensitivity for most purposes (Lee et al ., 2010; Stacey et al ., 2014), even for shorter task-based sampling at these concentrations. However, the cyclone might be considered bulky and heavy and so are the personal pumps necessary for its operation.…”

“…These studies have shown that samples collected with high flow rate samplers could provide precise analytical results, i.e. significantly above the limit of detection (LOD) and/or LOQ by increasing the mass collection on filters (Stacey and Thorpe, 2009; Lee et al ., 2010; Lee et al ., 2012; Coggins et al ., 2013; Stacey et al ., 2014). This study is part of an on-going collaboration between the National University of Ireland, Galway in Ireland and the National Institute for Occupational Safety and Health (NIOSH) in the USA.…”