AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
On-line Fluorescence Detection of Primary Biological Aerosol Particles (PBAP) in an Urban Environment Heavily Impacted by Black Carbon Particles
Stig Hellebust, David O'Connor, JOHN SODEAU, Dominique Baisnee, Roland Sarda-Esteve, Michel Thibaudon, Gavin McMeeking, Ian Crawford, Martin Gallagher, J. Alex Huffman, Virginia E. Foot, Jean-Maxime Roux, Christophe Bossuet, Walfried Lassar, Kyle Pierce, University College Cork
Abstract Number: 100 Working Group: Bioaerosols
Abstract A Wideband Integrated Bioaerosol Sensor (WIBS-4) was deployed on the roof of LHVP, Paris, France over two time periods, July 4 to July 13 and July 22 to August 8, during 2014. (BIODETECT2014 campaign). The instrument was co-located with an Aethalometer (AE 33, Magee Scientific) for measuring Black Carbon aerosol mass (BC) and a Hirst-type impaction trap (VPPS 2000, Lanzoni) to provide off-line counting and identification of airborne fungal spores present.
In total, 10,476,537 individual particles were detected and sized. Approximately 12% of these (1,273,356) particles gave rise to fluorescence signals in at least one of the WIBS-4 emission wavebands, 310-400 nm or 420-650 nm, when irradiated with UV light at either 280 nm or 370 nm. The basis of the detection method is that pollen and fungal spores contain biofluorophores, such as tryptophan, NAD(P)H and flavins, that give signals in at least one of these two wavebands. Hence the instrument allows real-time monitoring of airborne PBAPs. However confounding signals from fluorescent chemicals such as Poly Aromatic Hydrocarbons that are present in urban polluted atmospheres from sources such as traffic exhausts and domestic fuel burning need filtering out. The role of Black Carbon particles acting as a source of confounding signals is less well-established because in its pure state the material is non-fluorescent. However in polluted atmospheres there exists the potential for fluorescent chemicals to “piggy-back” on BC.
In the current study the real-time results, as verified by off-line data on the airborne PBAP present, show that it is possible to both identify and remove the confounding contribution of “BC”. This novel achievement was made possible here by applying a signal filtering procedure based on a combination of particle sizing, “shaping” and individual channel fluorescence.
This study is supported by the CBRN-E research program of CEA/DAM and EPA Ireland.