AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Measuring Changes over Time in Bioaerosol Spectral Signatures with the WIBS
ELIZABETH CORSON, Jonathan Eshbaugh, Johns Hopkins University Applied Physics Laboratory
Abstract Number: 324 Working Group: Environmental Fate of Infectious Aerosols
Abstract As biological aerosols are exposed to atmospheric processing, changes in viability and spectral signatures may occur. Interrogating particle fluorescence is a common method for detecting biological aerosol. Therefore, understanding changes in spectral signature over time is critical for accurate bioaerosol detection. The Wideband Integrated Bioaerosol Sensor (WIBS-4A, Droplet Measurement Technologies Inc.) provides measurements of particle fluorescence at two excitation wavelengths, 280 nm and 370 nm, and two emission spectra, 310-400 nm and 420-650 nm. This multichannel approach to fluorescence measurement produces informative data about the state of a bioaerosol population over time. Two bioaerosol aging campaigns were completed using a rotating drum to maintain an aerosol population and expose the aerosol to aging factors such as water vapor, ultraviolet light, and ozone. The aerosol was measured over time using a WIBS-4A and an Ultraviolet Aerodynamic Particle Sizer (UVAPS, TSI Inc.). Changes in spectral signatures over time were observed in a vegetative bacteria and a protein, especially when exposed to ozone and water vapor. Fluorescence data will be presented with an emphasis on methodology for investigating bioaerosol fate and how to interpret raw WIBS data in this context.