Model 3340 Laser Aerosol Spectrometer Bibliography - Tsi

Thompson, M.W.; Donnelly, J.; Grinshpun, S.A.; Juozaitis, A.; Willeke, K. “Method and Test System for
Evaluation of Bioaerosol Samplers,” Journal of Aerosol Science, 25:8, (1994) 1579–1593.
Abstract: A method and test system have been developed for the laboratory evaluation of the
performance of bioaerosol samplers. The method differentiates between the overall physical sampling
efficiency (which reflects the inlet and collection efficiencies) and the biological sampling efficiency
(which reflects the survival of the test microorganisms during the sampling process). The number
concentrations of laboratory-generated bioaerosol particles are measured with an aerosol size
spectrometer up- and downstream of the bioaerosol sampler being tested. In a bioaerosol impactor,
which was specially designed for testing microbiological aspects of bioaerosol sampling, the inlet and
collection efficiencies are differentiated by measuring downstream of the collection surface location
with and without the collection surface in place. The number of recovered particles is counted as
microcolonies with a microscope after sampling the bioaerosol particles into agar and culturing them.
The total recovery of these bioaerosol particles is determined as a ratio of the number of viable
microorganisms recovered to the number of bioaerosol particles present in the air sampling volume
upstream from the sampler. This total recovery is a measure of the ratio of culturable to nonculturable
bacteria present in the air. By measuring physical and microbiological aspects
simultaneously, information is gained on aspects of bioaerosol sampling that cannot be determined by
either of these branches of science alone. This is exemplified by tests on the influence of relative
humidity and desiccation time on colony count.
The newly-developed system can be used to test any bioaerosol sampler. A special single-stage
impactor was designed, built and used to study how different sampling and analysis variables affect
the total recovery of bioaerosol particles. The designed impactor was calibrated using PSL particles.
Its inlet sampling efficiency was found to be within the range of 96 to 99.5%, depending on the
sampling conditions and particle size, if the latter is less than 8 µm (this range represents single
bacteria, bacterial agglomerates, and fungi). The collection efficiency was found to be about 100%
when collecting PSL particles larger than 0.7 μm in diameter at 201 min −1 or higher air flows.
The total recovery of microorganisms measured under these conditions is characterized only by the
“survivability” of microorganisms during their sampling. It was found that relative humidity had a
pronounced effect on total Pseudomonas fluorescens recovery. Experimental data also showed that
the sampling time may be limited due to bacterial desiccation and subsequent loss in viability of
collected microorganisms.
1993
Peters, K.; Gerchau, J.; Bruckner, G. “The Filtering of Aerosol Particles by a Spruce Canopy-
Measurements Versus Model Calculations,” Journal of Aerosol Science, 24, (1993) S313–S314.
1992
Schiller-Scotland, C.F.; Hlawa, R.; Gebhart, J.; Wonne, R.; Heyder, J. “Total Deposition of Aerosol
Particles in the Respiratory Tract of Children during Spontaneous and Controlled Breathing,” Journal of
Aerosol Science, 23:S1, (1992) 457–460.
Abstract: Medical doctors found out that in comparison to adults the number of children with
airways decrease due to air pollution is much higher. However up to now experimentally data for total
deposition of aerosol particles in the human respiratory tract are predominantly published for adults.
In the present study 29 children with normal lung function data volunteered for the determination of
total deposition using an inline inhalation technique. It turns out that total deposition data for children
are higher than for adults, and thus confirm a general tendency already reported by BECQUEMIN et
al. (1986). Using the inline technique the differences in deposition values between children and adults
are more pronounced than found by those authors.
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