title: Development and evaluation of an inhalable bioaerosol manifold sampler.
abstract: This paper describes the development and evaluation of an inhalable bioaerosol manifold sampler for the collection of replicate samples over sequential sampling periods. Wind tunnel experiments at wind velocities < or = 0.6 m/sec (< or = approximately 120 ft/min) and at a sampling velocity of 0.6 m/sec yielded sampling efficiencies within 10% of the American Conference of Governmental Industrial Hygienists' inhalable curve up to particle diameters of about 18 microns and efficiencies within 18% for diameters up to 26 microns. At wind velocities > or = 0.6 m/sec, a sampling velocity of 0.8 m/sec yielded efficiencies that were within 15% of the inhalable curve up to diameters of about 22 microns and within 20% for diameters up to 25 microns. Microscopic counts of 15.6-micron and 25.6-micron monodisperse polystyrene beads aerosolized in the wind tunnel and collected with the manifold sampler yielded precise concentrations (pooled CV = 9.0 and 5.3%, respectively) averaging 115% and 92%, respectively, of measurements with the APS Model 3310 aerodynamic particle sizer. Field tests in a cotton dust environment demonstrated the ability to generate a time/concentration profile of fungal spores similar to that indicated for cotton dust levels determined with horizontal elutriators. Cotton dust was sampled efficiently while cotton fibers were excluded. Field tests on a dairy farm indicated no statistically significant bias (p = 0.72) between spore concentrations determined with the manifold sampler and concentrations determined through a central test port.
authors.affiliation: University of Alabama at Birmingham, Department of Environmental Health Sciences 35294, USA.
authors.forename: P
authors.initials: P
authors.lastname: Gao
authors.forename: H K
authors.initials: HK
authors.lastname: Dillon
authors.forename: W E
authors.initials: WE
authors.lastname: Farthing
mesh_terms: D000336:Aerosols; D000395:Air Pollutants, Occupational / Q000032:analysis*; D015982:Bias; D004784:Environmental Monitoring / Q000295:instrumentation*; D004867:Equipment Design; D005374:Filtration / Q000295:instrumentation; D006801:Humans; D010316:Particle Size; D015203:Reproducibility of Results
chemical_list: D000336:Aerosols; D000395:Air Pollutants, Occupational