10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
The Effect of Humidity on the Viability of Aerosolised Bacterial Agents
EMMA KEYSER, Carwyn Davies, DSTL
Abstract Number: 205 Working Group: Infectious Bioaerosol
Abstract In the event of an aerosol release of a biological agent, there is a need to understand the survival characteristics to evaluate the potential downwind impact. This is of vital importance for potential biological warfare agents, to assess the downwind hazard following release. To develop an understanding of the potential impact, it is necessary to investigate how different and varying environmental parameters can affect these aerosols. By altering these environmental parameters in a controlled laboratory environment, a full assessment of the survival characteristics of each pathogen can be determined.
Humidity is an important and variable factor that can have consequences on the stability and characteristics of a bioaerosol. Previous research, investigating the suspension of an aerosol over a prolonged period of time, has shown that relative humidity can affect the biological stability of a pathogen. Due to differing characteristics of individual pathogens, the impact of changing parameters, including humidity is likely to differ. For example, those pathogens that naturally thrive in wetter environments may benefit from higher levels of humidity, which may have a more detrimental impact on those that thrive naturally in relatively dry environments.
This study presents data showing the effects of different relative humidities on the stability and viability of a range of different pathogens contained within small particle aerosols over short distances and time from generation. Each pathogen was aerosolized at a range of humidities and evaluated using spray factor. Spray factor is one of the most effective ways of determining aerosol stability, and is calculated by taking the aerosol output and dividing it by the original concentration of the aerosol suspension. The spray factor was evaluated for a range of humidities for three different pathogens, including spore forming and vegetative cells.