Transfer of BW Surrogate Particles from Contaminated Surfaces
RICHARD BYERS, Steve Medley, et al.
Battelle Memorial Institute
Abstract Number: 149
Working Group: Aerosol Physics
Last modified: April 1, 2011
The BioWatch Program was designed to detect biological threat agents in the air, providing a warning to government and public health officials of potential bioterror events. If a biological threat agent was collected, the BioWatch sampler and surrounding area could be contaminated due to bioaerosol deposition. This contamination could pose a hazard to the sampler operator and may be a source of cross-contamination in clean areas. The operator could also pose a hazard to co-workers if the contamination was re-transferred to a laboratory/office. To assess this exposure source, Battelle performed a study using a Bacillus thuringiensis (Bt) spore powder preparation to investigate material transfer from a contaminated site to an individual, and from a contaminated individual to his or her surroundings. Air samples from an intentionally Bt-contaminated site showed reaerosolization of the spores, and analysis of swatches taken from the operatorís clothes showed substantial transfer of spores to the operator. After leaving the contaminated site, the operator entered a laboratory/office complex and performed common tasks. Air and surface samples were taken to measure reaerosolization and secondary transfer of bioaerosol particles. Transfer of material from the contaminated operator to clean surfaces was significant, with 3 to 8% of the biological material collected on the operator re-transferred to surfaces (floor tiles, desktops, carpet). Reaerosolization from the contaminated operator was also detected, as all rooms sampled were positive for aerosolized spores. Results from this study may provide insight into possible exposure hazards for BioWatch operators and the transfer of contaminants to secondary sites.