International Inter-comparison of Laser/Light-induced Fluorescence (L/LIF) Methods for the Real-time Detection of Bioaerosols: BIODETECT 2014 Campaign at CEA/LSCE ACTRIS SUPERSITE (Saclay, France)

In the frame of the Bio Chemical Collectors (BCC) CBRN-E research project the French Atomic Energy Commission (CEA) organized an inter-comparison of laser/light-induced fluorescence (L/LIF) methods for the detection and quantification of bioaerosols. A comprehensive suite of commercially available (L/LIF) technologies, as well as a set of new prototypes, were operated during the intensive measurement campaign, BIODETECT 2014. This campaign took place at the CEA/LSCE ACTRIS SUPERSITE in suburban Paris, France in July – August 2014. During this period of the year, high concentrations of pollen and fungal spores are emitted into the air; these emissions have been shown to frequently coincide with pollution events. Accordingly, a key objective of BIODETECT 2014 was to understand how (L/LIF) techniques operate in an urban/suburban environment, specifically with respect to their ability to detect bioaerosols from amongst high concentrations of non-biological particles. Single-particle (L/LIF) techniques were compared with the method of collecting particles onto sticky tape for subsequent visual identification and analysis. Such methods have been utilized routinely by the National Network of Survey for Airborne contaminants (RNSA) to identify pollens and fungal spores. Direct comparisons between optical microscope studies and (L/LIF) techniques have only been performed recently and not alongside other detailed measurements. To study the potential interferences to bioaerosol detection a broad set of ancillary instrumentation was also deployed, and source apportionment tools were employed to identify aerosols sources. This inter-comparison provided a robust evaluation of the ability of (L/LIF) systems to monitor pollen and fungal spores and has increased the knowledge for both bio-aerosol quantification and segregation in complex environments. The project also investigated the pertinence of shape factor or wavelength of excitation to distinguish the type of pollen that could generate allergies and other respiratory diseases