AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
A Novel Test Apparatus and Method for the Measurement of Biological Aerosol Viability Decay Under Controlled Environmental Conditions Using Synthetic Microfibers
Kevin Hommema, KENT HOFACRE, Michael Kuhlman, Traci Jordan, Battelle
Abstract Number: 45 Working Group: Environmental Fate of Infectious Aerosols
Abstract A key parameter of interest when modeling the downwind hazard of bioaerosols is the decay rate – the loss of viability with time while exposed to environmental conditions during transport. Previous studies designed to assess bioaerosol decay rates often do not permit quantitative conclusions to be drawn. Reasons for this include the inherent experimental difficulties associated with maintaining a stable aerosol and exposure conditions over necessary time durations (particularly for large particles), and many of the studies were performed at a time when the impacts of organism growth conditions and particle composition were not well understood.
Through recently completed efforts, a new test apparatus and methodology has been developed at Battelle where particles are captured onto 2-micrometer diameter microfibers and then remain affixed while exposed to controlled environmental conditions, rather than as free-floating particles. Once affixed to the microfibers, the particles can be exposed to well-controlled environmental conditions (e.g., solar radiation, ozone, and relative humidity) for any necessary time duration. The approach developed is based on and advances that of previous researchers using spider webs or artificial microfibers. The updated methodology significantly reduces the effort and variability associated with those environmental exposure methods and techniques.
Testing has demonstrated that this approach allows for individual organisms and agglomerate particles up to at least 10 micrometers in diameter to remain airborne for at least 72 hours without the confounding issues of particle loss by physical phenomenology such as gravitational setting, diffusion and adherence to test chamber surfaces, and dilution effects associated with aerosol sampling and/or dynamic control of the environmental conditions.
Test results will be presented demonstrating the ability to evaluate the decay of organism viability in bioaerosols when exposed to environmental conditions such as relative humidity, simulated solar light, and ozone. Recommendations for future work and applications will also be introduced.