NIOSH evaluation of air sampling methodologies for bacillus anthracis in a United States postal service processing and distribution center.
McCleery-R; Martinez-K; Burr-G; Mattorano-D
Abstracts of the 1st National Conference on Environmental Sampling for Bio-Threat Agents, January 27-28, 2005, Washington DC: Department of Homeland Security/Department of Defense, 2005 Jan; :1
During the week of February 4-7, 2002, NIOSH conducted a health hazard evaluation at the Trenton Processing and Distribution Center in response to a request from the United States Postal Service for collaborative research to evaluate air sampling methods for Bacillus anthracis spores before and after operation of a delivery bar code sorter (DBCS). Investigators collected 106 wipe samples using sterile polyester/rayon pads moistened with sterile water and 256 air samples using mixed cellulose-ester filters (MCE), polytetrafluoroethylene filters (PTFE), gelatin-coated filters (GEL), dry filter units with polyester felt filters (DFU), and Andersen single-stage cascade impactors containing trypticase soy agar plates with 5% sheep blood. All wipe samples were positive for B. anthracis indicating that the DBCS remained heavily contaminated. Initial air sample analyses (10% of the sample extract) indicated that before operating the DBCS, all MCE, PTFE, GEL, and DFU filters were negative for B. anthracis; however, 19% of Andersen samples were positive. After operating the DBCS, all sample media indicated some positive samples, which included 91% of the Andersen samples. The re-analysis (remaining 90% of sample extract) of previously negative filter samples collected before and after DBCS operation resulted in additional positive samples. This clearly demonstrates that all evaluated methods were capable of collecting B. anthracis spores to some degree, and that re-aerosolization occurred through mechanical means. Additionally, positive samples were found at various locations before DSCS operation, suggesting that walking and light work in the enclosure were sufficient in re-aerosolizing B. anthracis spores at low concentrations. The positive samples from the re-analysis indicate that the entire filter sample should be analyzed to improve the sensitivity of the analysis. This determination can be a significant factor in the selection of air sampling methodologies when considering the intent of sampling, e.g., screening, characterization, or clearance.
Air-samples; Air-sampling; Postal-employees; Air-sampling-techniques; Air-samplers; Filters; Sampling; Sampling-methods
Abstract; Conference/Symposia Proceedings
Abstracts of the 1st National Conference on Environmental Sampling for Bio-Threat Agents, January 27-28, 2005, Baltimore, Maryland