AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Multistage Cyclone Array for the Simultaneous Collection of Aerosol Mass in the Ultrafine, Submicron, Respirable, and Coarse Region
EMANUELE CAUDA, Steven Mischler, NIOSH
Abstract Number: 168 Working Group: Health Related Aerosols
Abstract The impact of exposure to occupational aerosol on workers’ health needs to be evaluated by simultaneously investigating the toxicity of the aerosol and the physical characterization of the particles. While current real-time monitors and off-line analysis can perform accurate physical characterization of the particles on very small samples, in-vitro toxicological analysis generally requires large amount of sample to be analyzed. This requirement induce the use of samplers that collect rapresentative and significant portion of the aerosol on media or substrates. For aerosols characterized by particles both in the micron and ultrafine region, the collection and analysis of size-segragated samples is also extremely useful for the investigation of different size-cut of the aerosol. This is typicall accomplished by using multistage impactors that collect particles on plates or filters. It is known that the collection of large amount of sample on a single impactor stage can modify the collection efficiency of the impactor by shifting its characteristics. This study investigated the use of a multi-stage cyclone system to collect crystalline silica particles from the coarse region to below 200 nm. The collection efficiency of the four stages - ultrafine, submicron, respirable, and coarse - was characterized by using real-time monitors, microscopy analysis, and dynamic light scattering on aerosol samples dispersed in liquid form prior the toxicity analysis. The study showed that the system is capable of providing sufficient amount of sample for toxicity analysis – in the order of milligrams – for every cut size, while maintaing consistent and accurate stage collection efficiency characteristics during the test.