Measured infrared spectral extinction for aerosolized Bacillus subtilis var. niger endospores from 3 to 13 μm

摘要

We measured spectral extinction in situ for aerosolized Bacillus subtilis var. niger endospores using Fourier-transform infrared spectroscopy from 3.0 to 13.0 μm. Corresponding aerosol size distributions were measured with a commercially available elastic light-scattering probe and verified by direct particle capture and subsequent counting by video microscopy. Aerosol mass density was monitored simultaneously with conventional dosimetry and was used to mass normalize the measured spectral extinction. Mie theory calculations based on measured distributions and available complex indices of refraction agreed well. We also present resultant Mie calculations for the absorption, total scattering, and backscatter. For comparison, measured spectral extinction for three common environmental aerosols is also presented, i.e., for water fog, diesel soot, and Arizona road dust.