American Association for Aerosol Research - Abstract Submission

AAAR 36th Annual Conference
October 16 - October 20, 2017
Raleigh Convention Center
Raleigh, North Carolina, USA

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Probing the Fundamentals of Bioaerosol Longevity as a Function of Atmospheric and Particle Compositions through Using a Next Generation Electrodynamic Balance

ALLEN E. HADDRELL, Mara Otero, Richard Thomas, Jonathan P. Reid, University of Bristol

     Abstract Number: 170
     Working Group: Bioaerosols

Abstract
The study of the fundamentals of bioaerosol is challenging. Firstly, there remain all the challenges associated with standard aerosol experiments (small sample size, broad concentration ranges), with the additional difficulty of studying the variability presented by micro-organisms residing in droplets (e.g. population variation, chemical composition). The methodologies currently employed in laboratory studies of bioaerosol are based on analytical approaches developed in the 1950s with minor adaptations (e.g. Goldberg drum). Numerous aspects of these technologies are problematic, from droplet generation (retaining viability, knowing chemical and biological composition (Zhen, 2014)), droplet suspension (avoiding wall loss, interaction with contaminants, etc.) and analysis (sampling inefficiency). Given these limitations, some basic questions about bioaerosol have yet to be fully answered (e.g. does the number of bacteria or chemical composition in a droplet influence the longevity and transmissibility of micro-organisms in the droplet?).

To be able to answer these fundamental questions, a novel technology has been developed and will be presented. This technology (utilizing electrodynamic levitation) produces and suspends a quantifiable number of near identical bioaerosol droplets within an atmosphere whose composition is controlled. Moreover, the complete chemical and biological composition of the droplets is tailorable. After a given period the droplets are extracted from the gas phase (at a 100% efficiency) onto a substrate wherein their viability is probed.

Of the many unique characteristics of this technology, the ability to produce droplets with identical chemical composition and size, with a similar absolute number of microorganism (±10%), is critical to being able to answer the most fundamental questions regarding bioaerosol. Some of the measurements to be presented include, the effect that the (a) absolute number of bacterium per droplet, (b) environmental parameters (e.g. relative humidity, temperature, solar irradiation), (c) biological species, and (d) chemical composition of the droplet itself, will have on longevity and infectivity.

Zhen, H. J.et al, G. J Aerosol Sci 2014, 70, 67.