Biological Aerosol Particle Measurements at a Rural Background Site: Ambient Comparison of UV-APS and WIBS-4 On-Line Techniques

David A. Healy (1), ALEX J. HUFFMAN (2), David O’Connor (1), Ulrich Pöschl (2), John R. Sodeau (1)

(1) University College Cork, Department of Chemistry, Cork, Ireland, (2) Max Planck Institute for Chemistry, Biogeochemistry Department, Mainz, Germany

     Abstract Number: 879
     Last modified: August 15, 2010

Abstract
Bioaerosols can influence atmospheric chemistry, effect earth climate and adversely effect human health. Several tropospheric field studies have shown that Primary Biological Aerosol Particulates (PBAPs) represent a significant fraction of airborne particulate matter. However, the detection, identification and quantification of PBAP remain challenging tasks and are often limited to laborious staining and counting methods. Prior to the recent development of instruments exploiting on-line detection of autofluorescence, time of flight measurements and spatial light scattering analysis the real-time measurements of ambient bioaerosol size distributions and estimation of shape with high time resolution have been difficult. The ultraviolet aerodynamic particle sizer (UV-APS, TSI Model #3314) and the wide issue bioaerosol sensor (WIBS-4, Univ. of Hertfordshire) represent two of the only commercially available instruments capable of detecting bioaerosols in real-time (Hairston et al., 1997; Kaye et al., 2005). Both instruments were co-located for approximately five weeks at a clean background site in Killarney National Park, Ireland. The results from each instrument show varying concentrations of fluorescent bioaerosol particles (FBAP) with frequent and nearly monodisperse peaks at approximately 3 um in size. FBAP concentrations of this particle mode were highest at night, peaking in the early morning and preliminary investigation suggests these particles to be fungal spores. In addition to the ambient background, a grass field immediately neighboring the sampling location was mowed on a semi-weekly basis and the data during these ~10 minute periods show the fluorescence behavior of emissions from freshly cut grass. The unique dataset presents the opportunity to relate the ability of each instrument to detect FBAP and enables the future comparison of datasets where only one instrument was in use.

References:
Hairston, P. P., et al. (1997) Journal of Aerosol Science, 28, 471-482.
Kaye, P. H., et al. (2005) Optics Express, 13, 3583-3593.