UV-C Decontamination of Aerosolized and Surface-Bound Single Spores and Bioclusters

Figures & data

FIG. 1 Flux measurements in μW/cm² of the aerosol chamber.

FIG. 2 UV-C survival fraction (+ standard deviation) curves for the single and BG cluster particles (2.8 and 4.4 μm) deposited on membrane filter surfaces. (Top) Survival fraction for fluence up to 1,000 J/m². (Bottom) Survival fraction for fluence up to approximately 25,000 J/m².

FIG. 3 The survival fraction (+ standard deviation) curve for aerosolized single and BG clusters (2.8 and 4.4 μm).

TABLE 1 The fluence values for 90% kill (D ₉₀) of BG spore clusters (2.8 and 4.4 μm) and individual spores on surfaces and in the air

	D 90	D 90
	values for	values for
	surface J/m^2	aerosol J/m^2
Single spores	138	27
2.8 μm clusters	725	42
4.4 μm clusters	1128	86–94*
*The D 90 value for 4.4 μm particles in the air was estimated.

TABLE 2 The first-stage rate constant (k ₁, m²/J) values for the two-stage decay curve for spores on surface, calculated using Equation (2)

	k 1 (m^2/J)
Single spores	0.012
2.8 μm clusters	0.008
4.4 μm clusters	0.003

TABLE 3 The rate constant (k) and multitarget exponent (n) values for the multihit target model for the aerosol exposure, calculated using Equation (3)

	n	k
Single spores	2.82	0.12
2.8 μm clusters	1.61	0.06
4.4 μm clusters	1.43	0.04