Comparison of COVID-19 infection risks through aerosol transmission in supermarkets and small shops

Abstract

Aerosol transmission is academically recognized as possible transmission route of Coronavirus disease 2019 (COVID-19). We established an approach to assess the airborne-disease infection risks through aerosol transmission based on the dose-response model and aerosol transport model. The accuracy of evaluation was guaranteed with on-site surveyed ventilation rate and occupant behavior. With the proposed approach, COVID-19 infection risks in 5 typical supermarkets and 21 small shops were evaluated. With one original infected early-shift staff, the average aerosols concentrations at steady-state are 1.06 × 10 −3 RNA copies/m 3 in the supermarkets and 4.73 × 10 −2 RNA copies/m 3 in the small shops. With the assumption of 5% original infected staff in the retail buildings, the infection probability of one customer is 1.40 × 10 −6 for visiting one small shop and 6.22 × 10 −6 for visiting one supermarket. The averaged infection risk in the supermarkets is higher than the small shops (p-value<0.001). On the other hand, the infection risks are higher for the staff working with the infected staff compared with the customers. The proposed approach can be applied to other occupied buildings and assist the pandemic control policy making for sustainable cities and society.

Tempo-spatial infection risk assessment of airborne virus via CO2 concentration field monitoring in built environment

“…This is supported by Ref. [ 36 ], with the different aerosols removal contributions of filtration and deposition in mechanical ventilation dominated supermarket and natural ventilation dominated small shops. As a result, the evaluation results from present approach could be taken as a conservative assessment of the infection risk with redundancy.…”

“…For example, Ref [ 11 , 45 ] considered the scenarios of waiting rooms of outpatient buildings, pharmacies, supermarkets, restaurants, post offices and the bank, with the most extended exposure duration taken as 190 min. Meanwhile, Ref [ 36 ] evaluated the infection risk of a supermarket salesperson after 8 hours of co-working with an infected colleague. However, the virus concentration in the supermarket was treated as homogeneous and fixed during most of the working hours.…”

“…The viral shedding rate can be calculated with Eqs. (15) , (16) ) [ 36 ]. Where σ i is the viral shedding rate by the infector (or infectors) (RNA copies/h).…”

“…As summarized in Ref. [ 36 ], the viral loads of SARS-CoV-2 in respiratory fluid are mainly in the range of 10 5 -10 7 RNA copies/ml, with an average of about 10 6 RNA copies/ml [ 36 ]. Therefore, the viral load is set to be 10 6 RNA copies/ml in the present study.…”

Commercial Buildings in Town. The Influence of Discount Shops on the Trade Structure of a Small Town

“…The ongoing COVID-19 pandemic is also an important factor that has affected many areas of urban life. E-commerce services have gained in importance as a modern shopping alternative, especially now with increased social distancing rules and customers habits [25,26].…”