Volume 15, No. 2, April 2015, Pages 365-375 PDF(1.53 MB)
Are There Generalizable Trends in the Release of Airborne Synthetic Clay Nanoparticles from a Jet Milling Process?
Ehsan Majd Faghihi1, Darren Martin2, Samuel Clifford1, Grant Edwards2, Congrong He1, Christof Asbach3, Lidia Morawska1
1 International Laboratory for Air Quality and Health, Queensland University of Technology, GPO Box 2434, Brisbane QLD, 4001, Australia
2 Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane QLD, 4072, Australia
3 Institut für Energie- und Umwelttechnik (IUTA) e.V., Air Quality & Filtration, Bliersheimer Str. 60, 47229 Duisburg, Germany
- Measurements and novel data analyses to characterize the release of nanoparticles.
- Factors taken into account: size and surface treatment of materials, and milling rate.
- Significant yet dissimilar effects of all factors on particle release.
- No implication of general particle release trend from this process.
- Each tested case should be handled individually in terms of exposure considerations.
Despite recent efforts to assess the release of nanoparticles to the workplace during different nanotechnology activities, the existence of a generalizable trend in the particle release has yet to be identified. This study aimed to characterize the release of synthetic clay nanoparticles from a laboratory-based jet milling process by quantifying the variations arising from primary particle size and surface treatment of the material used, as well as the feed rate of the machine. A broad range of materials were used in this study, and the emitted particles mass (PM2.5) and number concentrations (PNC) were measured at the release source. Analysis of variance, followed by linear mixed-effects modeling, was applied to quantify the variations in PM2.5 and PNC of the released particles caused by the abovementioned factors. The results confirmed that using materials of different primary sizes and surface treatment affects the release of the particles from the same process by causing statistically-significant variations in PM2.5 and PNC. The interaction of these two factors should also be taken into account as it resulted in variations in the measured particles release properties. Furthermore, the feed rate of the milling machine was confirmed to be another influencing parameter. Although this research does not identify a specific pattern in the release of synthetic clay nanoparticles from the jet milling process this is generalizable to other similar settings, it emphasizes that each tested case should be handled individually in terms of exposure considerations.
Airborne particles release; Workplace aerosol measurement; Nanotechnology.