title: Changes in fluorescence spectra of bioaerosols exposed to ozone in a laboratory reaction chamber to simulate atmospheric aging.
abstract: A laboratory system for exposing aerosol particles to ozone and rapidly measuring the subsequent changes in their single-particle fluorescence is reported. The system consists of a rotating drum chamber and a single-particle fluorescence spectrometer (SPFS) utilizing excitation at 263 nm. Measurements made with this system show preliminary results on the ultra-violet laser-induced-fluorescence (UV-LIF) spectra of single aerosolized particles of Yersinia rohdei, and of MS2 (bacteriophage) exposed to ozone. When bioparticles are exposed in the chamber the fluorescence emission peak around 330 nm: i) decreases in intensity relative to that of the 400-550 nm band; and ii) shifts slightly toward shorter-wavelengths (consistent with further drying of the particles). In these experiments, changes were observed at exposures below the US Environmental Protection Agency (EPA) limits for ozone.
authors: Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland 20723, USA.
authors: Joshua L
authors: JL
authors: Santarpia
authors: Yong-Le
authors: YL
authors: Pan
authors: Steven C
authors: SC
authors: Hill
authors: Neal
authors: N
authors: Baker
authors: Brian
authors: B
authors: Cottrell
authors: Laura
authors: L
authors: McKee
authors: Shanna
authors: S
authors: Ratnesar-Shumate
authors: Ronald G
authors: RG
authors: Pinnick
mesh_terms: D000336:Aerosols / Q000032:analysis*; D001272:Atmosphere / Q000737:chemistry*; D007753:Laboratories; D017909:Levivirus / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D015007:Yersinia / Q000737:chemistry*
chemical_list: D000336:Aerosols; D010126:Ozone