Immersive ultraviolet disinfection of E. coli and MS2 phage on woven cotton textiles.

ABSTRACT

Immersive ultraviolet disinfection provides a chemical-free technology for safer textiles, surfaces, and public spaces by inactivating communicable pathogens. This study examined immersive UV disinfection, using a disinfection cabinet, of E. coli and MS2 that was inoculated on white cotton T-shirts. The impact that porous materials have on UV disinfection is poorly understood with the majority of previous surface disinfection research focusing on hard, smooth surfaces. Several approaches were used in this study to characterize the light dynamics within the disinfection cabinet including colorimetric dosimetry coupons, biodosimetry, and spectroradiometry. Micro and macro geometry of porous surfaces are important factors to consider when using immersive UV technologies. The geometry of the cabinet impacted the distribution of emitted UV light within the disinfection cabinet and the physical properties of a porous material, such as the woven pattern of cotton, both contribute to UV disinfection efficiency. This work identified that light distribution is crucial for immersive UV technologies as the delivered fluence was highly variable within the disinfection cabinet and resulted in a difference of several logs of reduction for adjacent areas of T-shirt samples. Other inoculated areas achieved upwards of 1-log reductions values for MS2 and upwards of 2-log reductions for E. coli.