Exploration of electrostatic precipitation for bioaerosol collection.
Mainelis-G; Willeke-K; Grinshpun-S; Reponen-T; Hintz-P
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 1998 May; :38
Commonly used bioaerosol sampling mechanisms, such as impaction and impingement, are known to impart significant stress on microorganisms during the collection process. For quantitative exposure assessments in outdoor and indoor environments, bioaerosol collection methods with low microbial injury rates are desired. By imposing a small electrical charge on the bioaerosol" particles and then exposing them to an electric field, the particles can be gently collected on a collection medium. In our experiments we used a modified electrostatic aerosol sampler (EAS) (model 3100, TSI Inc., St. Paul, MN) to collect the airborne microorganisms by electrostatic forces. This sampler, originally designed to collect biologically inert particles was modified to hold an insertable collection trough. The experiments were performed with three types of airborne microorganisms, including one biochemically similar to Mycobacterium tuberculosis. Agar, water, and a filter were used as col1ection media. The physical collection efficiency of the sampler exceeded 80% for all three collection media and for all three microorganisms. The biological efficiency of this modified sampler was found to be greatly dependent on microorganism and collection medium used. When collected on a filter inside the EAS and then transferred to a nutrient medium, more than 90% of Bacillus subtilis spores, but only a few percent of sensitive Pseudomonas fluorescens bacteria were cultured. The microbial recovery of spores was also found to be significant, when collecting onto agar or into water. We conclude that the modified EAS can be used to enumerate culturable airborne bacteria. However, to optimize this technique for the collection of a wide range of bioaerosol particles, including very sensitive ones, the electrostatic and other sampling parameters need to be optimized in a new electrostatic bioaerosol sampler.
Aerosol-sampling; Quantitative-analysis; Exposure-assessment; Analytical-methods; Analytical-instruments; Microbial-test-systems; Microorganisms; Electrical-charge; Electrical-fields; Aerosol-particles; Electrostatic-precipitation; Samplers; Sampling-methods; Equipment-design; Equipment-reliability; Bacteria; Bacterial-cultures
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia