Transfer, Tracking, and Reaerosolization of a Biological Contaminant Following Field Operator Servicing of an Aerosol Sampler

Field personnel responsible for servicing currently deployed continuous bioweapon aerosol sampling units could become exposed, contaminated, and indirect sources of spore-bearing particles upon conducting sample retrieval duties. Given the capture of sporulated bio-agent particles at an aerosol sampling location, the unit and surrounding area are plausibly contaminated when operators enter the site to retrieve and replenish sample collection media. Such conditions provide opportunity for field personnel to accumulate contamination on clothing and inhale resuspended spores. Exposed air sample media is typically retrieved by field personnel on a 24-hour basis, with subsequent laboratory confirmation occurring several hours later. This delay, from the point of manual collection to sample analysis, allows time for personnel to visit, and possibly contaminate, indoor settings prior to interpretation of air sample results.;An investigation into the possibility of lasting exposure and cross-contamination from bioaerosol collection sites by field personnel was performed. A powder Bacillus thuringiensis spore preparation was disseminated upwind of a staged bioaerosol collection site at Battelle's Ambient Breeze Tunnel facility in Columbus, Ohio. Subsequent measurements were taken to characterize spore contaminant transfer and reaerosolization during field operator servicing of the air sampling unit. Additional surface and air samples were collected to characterize spore levels that resulted from the same field operator entering a clean indoor setting, after leaving the contaminated bioaerosol sampling site.;Air samples from this investigation indicated hazardous levels of reaerosolized spore-containing particles upon disturbance of a contaminated bioaerosol sampling site by field operator activity. In addition, analysis of swatches affixed to the operator's clothing, gloves, and shoes, suggested substantial transfer of biomaterial from contaminated surfaces. Significant levels of spores were also found to transfer from the contaminated field operator to a clean indoor office area, where subsequent reaerosolization occurred.;These observations contribute to the limited body of knowledge that exists regarding spore-particle transfer, tracking, and resuspension from contaminated individuals. Potential applications to similar civilian scenarios are also discussed.