Reducing airborne transmission of SARS-CoV-2 by an upper-room ultraviolet germicidal irradiation system in a hospital isolation environment

Haiyang Liu; Zhijian Liu; Junzhou He; Chenxing Hu; Rui Rong; Hao Han; Lingyun Wang; Desheng Wang

doi:10.1016/j.envres.2023.116952

Reducing airborne transmission of SARS-CoV-2 by an upper-room ultraviolet germicidal irradiation system in a hospital isolation environment

Environ Res. 2023 Nov 15;237(Pt 1):116952. doi: 10.1016/j.envres.2023.116952. Epub 2023 Aug 22.

Authors

Haiyang Liu¹, Zhijian Liu², Junzhou He¹, Chenxing Hu³, Rui Rong¹, Hao Han⁴, Lingyun Wang⁵, Desheng Wang⁵

Affiliations

¹ Department of Power Engineering, North China Electric Power University, Baoding, Hebei, 071003, PR China.
² Department of Power Engineering, North China Electric Power University, Baoding, Hebei, 071003, PR China. Electronic address: zhijianliu@ncepu.edu.cn.
³ School of Mechanical Engineering, Beijing Institute of Technology, Beijing, 100081, China.
⁴ State Key Laboratory of NBC Protection for Civilian, Beijing, 100191, China. Electronic address: thinkinghh@163.com.
⁵ State Key Laboratory of NBC Protection for Civilian, Beijing, 100191, China.

PMID: 37619635
DOI: 10.1016/j.envres.2023.116952

Abstract

Upper-room ultraviolet germicidal irradiation (UVGI) technology can potentially inhibit the transmission of airborne disease pathogens. There is a lack of quantitative evaluation of the performance of the upper-room UVGI for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) airborne transmission under the combined effects of ventilation and UV irradiation. Therefore, this study aimed to explore the performance of the upper-room UVGI system for reducing SARS-CoV-2 virus transmission in a hospital isolation environment. Computational fluid dynamics and virological data on SARS-CoV-2 were integrated to obtain virus aerosol exposure in the hospital isolation environment containing buffer rooms, wards and bathrooms. The UV inactivation model was applied to investigate the effects of ventilation rate, irradiation flux and irradiation height on the upper-room UVGI performance. The results showed that increasing ventilation rate from 8 to 16 air changes per hour (ACH) without UVGI obtained 54.32% and 45.63% virus reduction in the wards and bathrooms, respectively. However, the upper-room UVGI could achieve 90.43% and 99.09% virus disinfection, respectively, with the ventilation rate of 8 ACH and the irradiation flux of 10 μW cm^-2. Higher percentage of virus could be inactivated by the upper-room UVGI at a lower ventilation rate; the rate of improvement of UVGI elimination effect slowed down with the increase of irradiation flux. Increase irradiation height at lower ventilation rate was more effective in improving the UVGI performance than the increase in irradiation flux at smaller irradiation height. These results could provide theoretical support for the practical application of UVGI in hospital isolation environments.

Keywords: COVID-19 control; Hospital isolation environment; Indoor air quality; Irradiation flux; Upper-room UVGI.