Germicidal UV for the Control of Airborne Bacteria and Viruses: A Critical Review of Efficacy and the Production of Secondary Pollutants

This review addresses: the efficacy of GUV in inactivating airborne pathogens in laboratory experiments; the effect of pathogen structural characteristics and taxonomy on GUV susceptibility; and evidence that GUV produces airborne pollutants, all of which are key challenges to the widespread adoption of this technology.

With respect to the first objective, the median susceptibility constants <i>Z</i> for viruses and bacteria across all wavelengths were 2.2 cm² mJ^–1 and 3.5 cm² mJ^–1, respectively. GUV using 222 nm radiation has higher exposure thresholds than 254 nm, which permits a higher dose and is therefore likely more efficacious in practice. For the second objective, there is a difference in efficacy between bacterial families, dependent on cell wall characteristics, but there are not enough studies on viruses to determine whether their structural properties influence UV susceptibility.