title: Norovirus and MS2 inactivation kinetics of UV-A and UV-B with and without TiO2.
abstract: Germicidal ultraviolet, such as 254-nm UV-C, is a common method of disinfection of pathogenic enteric viruses. However, the disinfection efficacies of UV-A or -B in terms of inactivating waterborne viruses such as norovirus have not been characterized. We evaluated the inactivation kinetics of MS2 bacteriophage and murine norovirus (MNV), a surrogate of human norovirus (NoV), by UV-A and -B. In addition to UV disinfection, we further investigated whether the presence of TiO2 could enhance the virus inactivation kinetics of UV-A and -B. Both MS2 and MNV were highly resistant to UV-A. However, the addition of TiO2 enhanced the efficacy of UV-A for inactivating these viruses. UV-A dose of 1379 mJ/cm(2) resulted in a 4 log10 reduction. In comparison, UV-B alone effectively inactivated both MS2 and MNV, as evidenced by the 4 log10 reduction by 367 mJ/cm(2) of UV-B. The addition of TiO2 increased the inactivation of MS2; however, it did not significantly increase the efficacy of UV-B disinfection for inactivating MNV. When these treatments were applied to field water such as groundwater, the results were generally consistent with the laboratory findings. Our results clearly indicated that UV-B is useful for the disinfection of waterborne norovirus. However, MNV was quite resistant to UV-A, and UV-A effectively inactivated the tested viruses only when used in combination with TiO2.
authors.affiliation: Han River Environment Research Center, National Institute of Environmental Research, 819 Yangsoo-ri, Yangpyeong-goon, Gyeonggi Province 476-823, Republic of Korea; Department of Environmental Health and Institute of Health and Environment, School of Public Health, Seoul National University, 1st Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea.
authors.forename: Jung Eun
authors.initials: JE
authors.lastname: Lee
authors.forename: GwangPyo
authors.initials: G
authors.lastname: Ko
mesh_terms: D001435:Bacteriophages / Q000187:drug effects / Q000528:radiation effects; D004203:Disinfection; D007700:Kinetics; D029322:Norovirus / Q000187:drug effects / Q000528:radiation effects*; D014025:Titanium / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: C009495:titanium dioxide; D014025:Titanium
keywords: MS2 phage; Murine norovirus; Norovirus; Titanium dioxide; UV-A inactivation; UV-B inactivation