Evaluation of Eight Bioaerosol Samplers Challenged With Aerosols of Free Bacteria

Abstract

The need to quantify airborne microorganisms in the commercial microbiology industry (biotechnology) and during evaluations of indoor air quality, infectious disease outbreaks, and agriculture health investigations has shown there is a major technological void in bioaerosol sampling techniques to measure and identify viable and nonviable aerosols. As commercialization of microbiology increases and diversifies, it is increasingly necessary to assess occupational exposure to bioaerosols. Meaningful exposure estimates, by using area or environmental samplers, can only be ensured by the generation of data that are both precise and accurate. The Andersen six-stage viable (microbial) particle sizing sampler (6-STG) and the Ace Glass all-glass impinger-30 (AGI-30) have been suggested as the samplers of choice for the collection of viable microorganisms by the International Aerobiology Symposium and the American Conference of Governmental Industrial Hygienists. Some researchers consider these samplers inconvenient for evaluating industrial bioprocesses and indoor or outdoor environments. Alternative samplers for the collection of bioaerosols are available; however, limited information has been reported on their collection efficiencies. A study of the relative sampling efficiencies of eight bioaerosol samplers has been completed. Eight samplers were individually challenged with a bioaerosol, created with a Collison nebulizer, of either Bacillus subtilis or Escherichia coli. The samplers were evaluated under controlled conditions in a horizontal bioaerosol chamber. During each experimental run, simultaneous samples were collected with a reference AGI-30 to verify the concentration of microorganisms in the chamber from run to run and day to day.(ABSTRACT TRUNCATED AT 250 WORDS)

The index of microbial air contamination

“…Many papers have been published, in which the efficiency of different samplers is evaluated and compared. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] The results are always the same: the final counts differ from one device to the next. Thus 'there is often no obvious choice of the correct sampler to use '.…”

Method to Determine the Number of Bacterial Spores Within Aerosol Particles

“…Before this attack, most scientists (and likely also the perpetrators) would have not expected that spores could disperse through envelopes and buildings at the extent that anthrax spores did. Although studies abound on the physical principles governing aerosols and on the characteristics of many aerosol collectors (Placencia et al 1982;Jensen et al 1992;Nevalainen et al 1992;Mainelis et al 1999;Griffiths and Steward 1999;Aizenberg et al 2000), quantifying the bacterial content of individual aerosols particles needs to be examined further.…”

Biological Efficiency Testing According ISO 14698-1

“…The comparative tests were performed in an indoor room (7.0x 4.5x 4.0 m.) with doors and windows closed with the purpose to evaluate the microbial population in the room's atmosphere [4][5][6]. No people were present during the tests.…”