Effect of ultraviolet irradiation on vitality and size distribution of adenovirus aerosols

Abstract

Objective To investigate the effect of ultraviolet(UV)irradiation on vitality and size distribution of adenovirus aerosols. Methods The adenovirus was aerosolized in a 2000 L chamber using a TK-3 aerosol generator, exposed to 254 nm or 365 nm UV, and sampled using a FA-1 six-grade impact sampler. The relative genome copy number of virus in the aerosol was detected by real-time fluorescence quantitative(FQ) PCR. The number of virus-infected PK15 cells was examined by counting cells with green fluorescence under a fluorescent microscope. Results The FQ-PCR results and virus-infected PK15 cells counts showed that virus in aerosols was most abundant in grade 6. 254 nm UV irradiation for 5 rain led to a sharp decrease of the cells with green fluorescence. No fluorescence cells were found after 30 rain irradiation.365 nm UV irradiation for 30 min did not change the green fluorescence cell count obviously. Although no adenovirus infected cells were observed by 254 nm UV irradiation for 30 min, the PCR results showed that there was still high number of virus genome detected in the aerosol. Conclusions 254 nm UV is more effective than 365 nm UV for inactivating adenovirus aerosols. The UV Irradiation does not interfere with the adenovirus aerosolsize distribution. Detecting of the virus genome copy number may not represent the vitality of virus. Key words: Ultraviolet rays; Adenovirus; Aerosol; Green fluorescence