Journal de bioterrorisme et de biodéfense

Abstrait

Detection Efficiency Comparison of the UV-APS and TACBIO using Inert Fluorescent and Biological Particles

Praveena Mylvaganam, Valerie Alstadt, Gary Kilper, Aime Goad and Jana Kesavan

Airborne CB threats have evolved into a serious and omnipresent battlefield threat against US military forces. Real time detection of these agents is an essential tool in the war against terrorism; government agencies employ fluorescent based aerosol detectors to provide real-time detection of these airborne biological particles. The TSI Model 3314 UVAPS has been used as the gold standard in military studies for detecting and quantifying airborne bio-threat particles for many years, however, the system was designed for laboratory applications and has several drawbacks; it is bulky, very expensive, and is no longer in production. This study evaluated the performance of a small and inexpensive aerosol detector, the TACBIO, as a low cost alternative to the UV-APS in aerosol detection. In this test, both systems were evaluated against aerosolized monodispersed polystyrene latex microspheres (PSLs) (1.4, 1.9, and 2.6 μm) and monodisperse bacteria spore clusters. Three Bacillus anthracis Ames simulant organisms were used in the bio test: Bacillus atrophaeus var. globigii (Bg), Bacillus thuringiensis (Bt), Bacillus anthracis Sterne (BaS). In the second part of the test, the counting efficiency of both instruments were compared by sampling 3 μm fluorescent PSL microspheres from a chamber. The counts obtained from both instruments were correlated to determine how well their detection efficiencies match up. The resulting data demonstrate that the TACBIO tracks the detection efficiency of UV-APS very well when sampling 3 μm PSL microspheres. The detection efficiency of the UV-APS and TACBIO were close to 100% for PSL microspheres and Bt and BaS particles, however, the TACBIO results for Bg were slightly lower due to the lower fluorescence properties of Bg. In spite of this minor difference, the TACBIO performed well in comparison to the much more expensive UV-APS systemes.