Study of SARS-CoV-2 transmission in urban environment by questionnaire and modeling for sustainable risk control

Abstract

Caused by SARS-CoV-2, COVID-19 has become a severe threaten to society and human health, its epidemic control emerges as long-term issue. A sustainable epidemic and environmental transmission risk control (SEERC) in urban area is urgently needed. This work aims to conduct a new investigation on the transmission risk of SARS-COV-2 as virus/hazardous material through various environmental medias, routes and regions in the entirely urban area for guiding the SEERC. Specifically, 5 routes in 28 regions (totally 140 scenarios) are considered. For a new perspective, the risk evaluation is conducted by the quantification of frontline medicals staffs' valuable experience in this work. 207 specialists responsible for the treatment of over 9000 infected patients are involved. The result showed that degree of risk was in the order of breath>contact-to-object>contact-to-human>intake>unknown. The modeling suggested source control as the prior measure for epidemic control. The combination of source control & mask wearing showed high efficiency in SEERC. The homeworking policy needed to cooperate with activity limitation to perform its efficiency. Subsequently, a new plan for SEERC was discussed. This work delivered significant information to researchers and decision makers for the further development of sustainable control for SARS-COV-2 spreading and COVID-19 epidemic.

Keywords: Frontline medical staff; Lab-experiment independent; New modeling; SARS-CoV-2; Sustainability.

Graphical abstract

Fig. 1

The schematic diagram of SARS-COV-2 development modeling.

Fig. 2

The degree of risk in all parts included in this study in the urban region. ((a) Infectious hospital; (b) General hospital; (c) Urban district; (d) Pollution control; ICU=ICU/Operation room; Clinic=Clinic/Emergency; Lab=Laboratory room; Imaging=Medical imaging room; Inpatient=Inpatient department; SP=Sewage pipe; WW=Wastewater treatment station; Gar/Garbage=Garbage storage/transportation station; AS=Air conditioning system; Con-object=Contact to object; Con-human=Contact to human; Residence=Residential area; Fre-m=Fresh market; Sup-m=Supermarket; Res/hot=Restaurant/hotel; Gar/squ=Garden/square; WTP=Wastewater treatment plant; Sludge=Sludge disposal; Ref-b=Refuse burning; Ref-t = Refuse transportation.)

Fig. 3

The degree of risk in various (a) routes and (b) areas in urban region.

Fig. 4

The ESVQ variation (SARS-CoV-2 spreading) with the time length of 10 days after the first infection source appeared. ((a). (b) ESVQ variation in 4 functional regions with no epidemic control measures; (b) ESVQ variation in residential area with source control measure, ratio from 0 to 1; (c) ESVQ variation in residential area with activity limitation measure, ratio from 0 to 1; (d) ESVQ variation in residential area with homeworking measure, ratio from 0 to 1; (e) ESVQ variation in residential area with mask wearing measure, ratio from 0 to 1.).

Fig. 5

The ESVQ variation (SARS-CoV-2 spreading) at the 10th day after the first infection source appeared with single and combined epidemic control measures in the residential area. (The numbers after the abbreviation of various control measures indicated their degrees, from 0.2 to 0.8.).

Fig. 6

The analysis of SEERC plan with various measures and control levels.