Aerodynamic Characteristics and RNA Concentration of SARS-CoV-2 Aerosol in Wuhan Hospitals during COVID-19 Outbreak

Yuan Liu; Zhi Ning; Yu Chen; Ming Guo; Yingle Liu; Nirmal Kumar Gali; Li Sun; Yusen Duan; Jing Cai; Dane Westerdahl; Xinjin Liu; Kin-fai Ho; Haidong Kan; Qingyan Fu; Ke Lan

The sampling was conducted between February 17 and March 2, 2020 in the locations by two batches as shown in Table 1 . All aerosol samples were collected on presterilized gelatin filters (Sartorius, Germany). Total of 30 TSP aerosol samples were collected on 25 mm diameter filters loaded into styrene filter cassettes (SKC Inc, US) and sampled air at a fixed flow rate of 5.0 litre per minute (LPM) using a portable pump (APEX2, Casella, US). Total of 3 size segregated aerosol samples were collected using a miniature cascade impactor (Sioutas impactor, SKC Inc., US) that separate aerosol into five ranges (> 2.5 The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.03.08.982637 doi: bioRxiv preprint to 0.25 μ m on 37 mm filters) at a flow rate of 9.0 LPM. Total of 2 aerosol deposition samples were collected using 80 mm diameter filters packed into a holder with an effective deposition area of 43.0 cm 2 and the filters were placed on the floor in two corners of Renmin Hospital ICU room intact for 7 days. Sampling durations and operation periods are detailed in Table S1 . Prior to the field sampling, the integrity and robustness of experiment protocol was examined in the laboratory and described in Supplementary Appendix (Table S2 ).