title: Evaluation of sampling methods for Bacillus spore-contaminated HVAC filters.
abstract: The objective of this study was to compare an extraction-based sampling method to two vacuum-based sampling methods (vacuum sock and 37mm cassette filter) with regards to their ability to recover Bacillus atrophaeus spores (surrogate for Bacillus anthracis) from pleated heating, ventilation, and air conditioning (HVAC) filters that are typically found in commercial and residential buildings. Electrostatic and mechanical HVAC filters were tested, both without and after loading with dust to 50% of their total holding capacity. The results were analyzed by one-way ANOVA across material types, presence or absence of dust, and sampling device. The extraction method gave higher relative recoveries than the two vacuum methods evaluated (p≤0.001). On average, recoveries obtained by the vacuum methods were about 30% of those achieved by the extraction method. Relative recoveries between the two vacuum methods were not significantly different (p>0.05). Although extraction methods yielded higher recoveries than vacuum methods, either HVAC filter sampling approach may provide a rapid and inexpensive mechanism for understanding the extent of contamination following a wide-area biological release incident.
authors.affiliation: U.S. Environmental Protection Agency, National Homeland Security Research Center, Research Triangle Park, NC, USA. Electronic address: calfee.worth@epa.gov.
authors.forename: M Worth
authors.initials: MW
authors.lastname: Calfee
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Rose
authors.affiliation: U.S. Environmental Protection Agency, National Homeland Security Research Center, Research Triangle Park, NC, USA; Oak Ridge Institute for Science and Education, Research Triangle Park, NC, USA.
authors.forename: Jenia
authors.initials: J
authors.lastname: Tufts
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Morse
authors.affiliation: ARCADIS Geraghty & Miller, Inc., Durham, NC, USA.
authors.forename: Matt
authors.initials: M
authors.lastname: Clayton
authors.affiliation: ARCADIS Geraghty & Miller, Inc., Durham, NC, USA.
authors.forename: Abderrahmane
authors.initials: A
authors.lastname: Touati
authors.affiliation: ARCADIS Geraghty & Miller, Inc., Durham, NC, USA.
authors.forename: Nicole
authors.initials: N
authors.lastname: Griffin-Gatchalian
authors.affiliation: Kultech Inc., Cary, NC, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Slone
authors.affiliation: ARCADIS Geraghty & Miller, Inc., Durham, NC, USA.
authors.forename: Neal
authors.initials: N
authors.lastname: McSweeney
mesh_terms: D061808:Air Filters / Q000382:microbiology*; D001407:Bacillus / Q000302:isolation & purification*; D001431:Bacteriological Techniques / Q000379:methods*; D013048:Specimen Handling / Q000379:methods*; D013171:Spores, Bacterial / Q000302:isolation & purification*
keywords: Anthrax; Bacillus anthracis; HVAC sampling; biological agent; bioterror