Investigation of cut-off sizes and collection efficiencies of portable microbial samplers

Details

• Personal Author:
  Mainelis G ; Yao M
• Description:
  This research investigated the physical collection efficiencies and cut-off sizes of SMA MicroPortable, BioCulture, Microflow, Microbiological Air Sampler (MAS-100), Millipore Air Tester (MAT), SAS Super 180, and RCS High Flow portable microbial samplers when collecting Polystyrene Latex particles ranging from 0.5 to 9.8 um in aerodynamic size. Traditional collection efficiency measurements often directly compare particle concentrations upstream and downstream of the sampler without considering the particle losses. Here, we developed a new approach which tests collection efficiencies of the sampler with and without agar collection plate loaded. This method thus allows estimating the effective collection efficiency, i.e., the fraction of incoming particles deposited onto the agar collection medium only. The experimental cut-off sizes, or d50, of the investigated samplers ranged from 1.2 um for the RCS High Flow, 1.7 um for the MAS-100, 2.1 um for SAS Super 180, to 2.3 um forMAT; for other three samplers they were close to or above 5 um. In most cases the theoretical d50 was lower than the experimental value, which was likely due to the dissipation of impactor jets and the influence of cross-flow in the multi-nozzle impactors. For most samplers, we observed a notable difference between the collection efficiency obtained by the traditional measurement method and the effective collection efficiency. In general, all samplers collected 10% or less of 0.5 um particles onto the agar medium. This study indicates that the use of most of the tested bioaerosol samplers may result in a substantial underestimation of bacterial concentrations, especially of single bacterial cells with diameter 0.5-1.0 um. On the other hand, most of the investigated samplers would be more efficient when collecting larger fungal spores. [Description provided by NIOSH]
• Subjects:
  Air Pollutants, Occupational Air Pollution Air Pollution, Indoor Environmental Monitoring Fungi Microbiology Occupational Health Particulate Matter Respiratory System Safety
• Keywords:
  Air-contamination Air-quality Air-samples Air-sampling Air-sampling-equipment Airborne-particles Analytical-processes Bacteria Exposure-assessment Exposure-methods Inhalation-studies Microbial-test-systems Particle-aerodynamics Particulate-dust Particulate-sampling-methods Sampling Sampling-methods

  More +
• ISSN:
  0278-6826
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  New Jersey ; OSHA Region 2
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  40
• Issue:
  8
• NIOSHTIC Number:
  nn:20044414
• Citation:
  Aerosol Sci Technol 2006 Aug; 40(8):595-606
• Email:
  mainelis@envsci.rutgers.edu
• Federal Fiscal Year:
  2006
• Performing Organization:
  Rutgers, The State University of New Jersey, New Brunswick
• Peer Reviewed:
  True
• Start Date:
  20040901
• Source Full Name:
  Aerosol Science and Technology
• End Date:
  20080831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:67b3e0e1cfcc26bd813cee66649543ab9b509ce0b5892bf42e2aff6afbb3402b0feffa3bd2d1714fa92466d4d71f323a0a69260dae3d7ed9bfbe90d6cbe28d5a
• Download URL:
  https://stacks.cdc.gov/view/cdc/200120/cdc_200120_DS1.pdf
• File Type:
  [PDF - 3.93 MB ]