Performance of portable microbial samplers when collecting inhalable particles.
American Industrial Hygiene Conference and Exposition, May 13-16, 2006, Chicago, Illinois. Fairfax, VA: American Industrial Hygiene Association, 2006 May; :40
Portable microbial samplers are increasingly used for determining exposure to biological aerosols. However, only limited information is available about the performance characteristics of such samplers. Thus, the objective of this study was to investigate the physical collection efficiencies of several portable microbial samplers when collecting inhalable biological and non biological particles and to determine their conformity to inhalation convention. The tested samplers included RCS HighFlow, BioCulture, Microflow. Microbiological Air Sampler, SMA MicroPortable, SAS Super 180, and Millipore Air Tester. All these samplers collect biological particles on agar media and their built-in sampling flow rates range from 30 to 180 L/min. The physical collection efficiencies of the samplers were determined using polystyrene latex particles ranging from 0.5 to 5.2 um in aerodynamic size and six species of bacteria and fungi ranging in aerodynamic diameter from 0.6 to 3.2 um. The collection efficiency was determined by isokinetically measuring particle concentrations upstream and downstream of the samplers and also separately determining particle losses inside the samplers due to air movers positioned behind the collection media. Experimental results have shown that all evaluated samplers collect less than 10% of 0.5 um particles. The effective d(50) or cut-off sizes, of the investigated samplers depended on the sampler model and ranged from 1.2 um for the RCS High Flow operating at 100 L/min to above 5.2 um (SMA Microportable operating at 141.5 L/min. BioCulture operating at 120 L/min, and Microflow operating at 120 L/min). Comparison of the samplers' collection characteristics with the sampling convention for total inhalable particles revealed that relative to the inhalation convention most of the investigated portable microbial samplers would under-sample investigated particles including tested bacteria and fungi. The obtained results indicate that application of the tested portable bioaerosol samplers for biological exposure assessment may result in underestimation of the inhalable airborne microorganism concentrations.
Samplers; Sampling-equipment; Sampling-methods; Aerosols; Aerosol-sampling; Aerosol-particles; Bacterial-dusts; Bacteria; Microorganisms
American Industrial Hygiene Conference and Exposition, May 13-16, 2006, Chicago, Illinois
Rutgers, The State University of New Jersey, New Brunswick