title: Suitability of ultraviolet (A)-light emitting diode for air stream disinfection.
abstract: We previously developed a high powered light-emitting diode device capable of discharging germicidal ultraviolet irradiation (UVA-LED) at an approximate wavelength of 365 nm. This study examined the bactericidal activity of UVA-LED in moving air streams. Aerosols of Escherichia coli DH5alpha were exposed to UVA-LED irradiation using a stable current (0.5 A and 1.2 mW/cm(2)) or pulse current (1.0 A and 0.2 mW/cm(2)). Settle plate analysis was used for bioaerosol sampling, where results were expressed as Colony Forming Units. A -3 Log inactivation of the E. coli population occurred after 75 minutes of constant exposure to stable current. The pulse current produced inactivation within a similar timeframe. Our results might be significant as a basic study for further investigations about the effect of UVA-LED on airborne bacteria and its suitability for air disinfection applications.
authors.affiliation: Department of Preventive Environment and Nutrition, Institute of Health Biosciences, the University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Gadelmoula
authors.forename: Xin
authors.initials: X
authors.lastname: Lian
authors.forename: Miku
authors.initials: M
authors.lastname: Maeda
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Aihara
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Mawatari
authors.forename: Akiko
authors.initials: A
authors.lastname: Hamamoto
authors.forename: Yumi
authors.initials: Y
authors.lastname: Harada
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamato
authors.forename: Masatake
authors.initials: M
authors.lastname: Akutagawa
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nakaya
authors.forename: Yohsuke
authors.initials: Y
authors.lastname: Kinouchi
authors.forename: Akira
authors.initials: A
authors.lastname: Takahashi
mesh_terms: D000336:Aerosols; D000391:Air Microbiology; D016902:Air Pollution, Indoor; D004203:Disinfection / Q000295:instrumentation*; D004926:Escherichia coli / Q000528:radiation effects; D006801:Humans; D018877:Sick Building Syndrome / Q000382:microbiology / Q000517:prevention & control; D014466:Ultraviolet Rays
chemical_list: D000336:Aerosols