removal of microorganisms by uvc radiation from the air of hospital

Currently, uvc radiation is used in hospitals to eliminate microorganisms and reduce adverse healtheffects in operating rooms (ors) and protective environment rooms (pers). the purpose of this studywas to investigate the effect of uvc irradiation on bioaerosols in ors and pers. this experimental studywas performed in ors and pers in a hospital. bioaerosols were evaluated according to the nationalinstitute for occupational safety and health (niosh) standard (no. 0800). the samples were collectedfrom indoor air of rooms before irradiation and after uvc (254 nm) irradiation for 20 and 480 minutes. thesample size of the study was determined to be 432 (216 fungi and 216 bacteria). the difference betweenthe mean concentration of bioaerosols in the uvc radiation at two intervals (20 and 480 minutes) wassignificant, which indicates a decrease in the concentration of bioaerosols by increasing the duration ofuvc radiation. some bacteria, such as group b streptococcus, lactobacillus, and listeria, were entirelykilled after 20 minutes of irradiation; however, complete removal of the bacteria such as staphylococcuspneumoniae and staphylococcus saprophyticus was observed after 480 minutes of uvc irradiation. fungi,such as alternaria, stofelim, and mucor had a 100% reduction after 20 minutes of uvc irradiation, andrhizopus and aspergillus fumigatus showed a 100% decrease after 480 minutes of uvc irradiation. otherisolated fungi such as cladosporium, penicillium, aspergillus niger, rhodotorula, and alternaria showeda decrease of 75%-98.78%. the ultraviolet (uv) sensitivity of bacterial and fungal bioaerosols dependsstrongly on their type. the results from this study may offer an important understanding of the control ofindoor bioaerosols using uvc irradiation and help abate the environmental impacts of airborne microbes.