Changes of optical properties and viability from aging bioaerosols under various laboratory controlled atmospheric conditions in an advanced rotating drum
Abstract
Airborne aerosol particles, including bioaerosol and chemical aerosol, play a very important role in atmosphere, where their physical, chemical, and biological properties, and their interactions with the environments have significant impacts on the climate and human health. Here, an advanced rotating drum was developed to study the reactions or aging of aerosols under various controlled atmospheric conditions. These simulated conditions are controlled relative humidity (RH), ozone, solar radiation, and volatile organic compounds (VOCs), either toluene or α-pinene. In the setup, a series of mass-flow controllers were incorporated to deliver reproducible, on-demand concentrations of VOCs, ozone, or RH into the drum along its center-axis. Three types of bioaerosols, Bacillus thuringiensis al Hakam spores, vegetative bacteria E. coli, and the virus simulant MS-2, were produced to investigate the effects of these variables, either with single or combined inputs. The drum rotated at 1 rpm to maintain aerosol ( 2 mm in size) suspending in the drum for hours during the aging and measuring process.
Aerosol concentration, size distribution, and single particle fluorescence spectra via 263-nm and 351-nm illuminations were monitored for 4-5 hours for each condition and repeated 3 times. In addition, the viability and genomic signature were measured from AGI-30 impinger collected samples to compare the difference before and after the reactions. Results show that the fluorescence spectral profile and intensity, the viability, and PCR signature change with time in the presence of one, or combinations of two, three, or four of the controlled variables. These variables have different effects and strengths for the aging process. The below figure shows one of the results, i. e. the time-averaged change rates of three fluorescence bands and viability under various conditions for aerosolized E. coli spores.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.A43K3209P
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0320 Cloud physics and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0368 Troposphere: constituent transport and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSES