Sustainable Cities and Society, Год журнала: 2021, Номер 76, С. 103424 - 103424
Опубликована: Окт. 4, 2021
Язык: Английский
Environmental Science & Technology, Год журнала: 2022, Номер 56(2), С. 1125 - 1137
Опубликована: Янв. 5, 2022
Some infectious diseases, including COVID-19, can undergo airborne transmission. This may happen at close proximity, but as time indoors increases, infections occur in shared room air despite distancing. We propose two indicators of infection risk for this situation, that is, relative parameter (Hr) and (H). They combine the key factors control disease transmission indoors: virus-containing aerosol generation rate, breathing flow masking its quality, ventilation aerosol-removal rates, number occupants, duration exposure. COVID-19 outbreaks show a clear trend is consistent with enable recommendations to minimize risk. Transmission typical prepandemic indoor spaces highly sensitive mitigation efforts. Previous measles, influenza, tuberculosis were also assessed. Measles much lower values than while are observed higher values. Because both diseases accepted airborne, fact less contagious measles does not rule out It important future outbreak reports include information on masking, exposure, investigate
Язык: Английский
Процитировано
163
Building and Environment, Год журнала: 2021, Номер 205, С. 108278 - 108278
Опубликована: Авг. 23, 2021
A novel modified version of the Wells-Riley model was used to estimate impact relative humidity (RH) on removal respiratory droplets containing SARS-CoV-2 virus by deposition through gravitational settling and its inactivation biological decay; effect RH susceptibility not considered. These effects were compared with achieved increased ventilation rate outdoor air. Modeling performed assuming that infected person talked continuously for 60 120 min. The results modeling showed infection risk depended size range virus-laden droplets. 0.5 ACH, change between 20% 53% predicted have a small risk, while at 6 ACH this had nearly no effect. On contrary, increasing from decrease half which is remarkably larger RH. It thus concluded more beneficial reducing airborne levels than changing indoor
Язык: Английский
Процитировано
69
Journal of Building Engineering, Год журнала: 2022, Номер 64, С. 105599 - 105599
Опубликована: Ноя. 26, 2022
In the past few years, significant efforts have been made to investigate transmission of COVID-19. This paper provides a review COVID-19 airborne modeling and mitigation strategies. The simulation models here are classified into infectious risk numerical approaches for spatiotemporal transmissions. Mathematical descriptions assumptions on which these based discussed. Input data used in previous studies assess dispersion extracted reported. Moreover, measurements performed study within indoor environments introduced support validations anticipated future studies. Transmission strategies recommended recent include modifying occupancy ventilation operations, using filters air purifiers, installing ultraviolet (UV) disinfection systems, personal protection compliance, such as wearing masks social distancing. application various building types, educational, office, public, residential, hospital, is reviewed. Recommendations works also discussed current apparent knowledge gaps covering both approaches. Our findings show that different measures were environments; however, there no conclusive work reporting their combined effects level may be achieved. further should conducted understand better balance between mitigating viral transmissions buildings energy consumption.
Язык: Английский
Процитировано
58
Building and Environment, Год журнала: 2022, Номер 219, С. 109232 - 109232
Опубликована: Май 26, 2022
Язык: Английский
Процитировано
49
Journal of The Royal Society Interface, Год журнала: 2023, Номер 20(203)
Опубликована: Июнь 1, 2023
The mechanistic factors hypothesized to be key drivers for the loss of infectivity viruses in aerosol phase often remain speculative. Using a next-generation bioaerosol technology, we report measurements aero-stability several SARS-CoV-2 variants concern droplets well-defined size and composition at high (90%) low (40%) relative humidity (RH) upwards 40 min. When compared with ancestral virus, Delta variant displayed different decay profiles. At RH, viral approximately 55% was observed over initial 5 s both variants. Regardless RH variant, greater than 95% lost after min being aerosolized. Aero-stability correlate their sensitivities alkaline pH. Removal all acidic vapours dramatically increased rate decay, 90% 2 min, while addition nitric acid vapour improved aero-stability. Similar artificial saliva growth medium observed. A model predict is proposed: pH exhaled drives loss; salt content limits infectivity.
Язык: Английский
Процитировано
27
The Science of The Total Environment, Год журнала: 2024, Номер 923, С. 171308 - 171308
Опубликована: Март 2, 2024
Respiratory disease transmission in indoor environments presents persistent challenges for health authorities, as exemplified by the recent COVID-19 pandemic. This underscores urgent necessity to investigate dynamics of viral infection within environments. systematic review delves into methodologies respiratory settings and explores how quality air (IAQ) can be controlled alleviate this risk while considering imperative sustainability. Among 2722 articles reviewed, 178 were retained based on their focus IAQ. Fifty eight delved SARS-CoV-2 transmission, 21 papers evaluated IAQ contexts other pandemics, 53 assessed during pandemic, 46 examined control strategies mitigate infectious transmission. Furthermore, investigating strategies, only nine considered energy consumption. These findings highlight clear gaps current research, such analyzing surface samples specific environments, oversight outdoor parameters (e.g., temperature, relative humidity (RH), building orientation), neglect occupancy schedules, absence considerations consumption enhancing study distinctly identifies environmental conditions conducive thriving each virus, offering trade-offs dominant viruses at any given time. argues that future research should involve digital twins conjunction with machine learning (ML) techniques. approach aims enhance patterns various
Язык: Английский
Процитировано
10
Building and Environment, Год журнала: 2021, Номер 204, С. 108131 - 108131
Опубликована: Июль 12, 2021
Язык: Английский
Процитировано
57
Science and Technology for the Built Environment, Год журнала: 2021, Номер 27(10), С. 1331 - 1367
Опубликована: Сен. 13, 2021
The COVID-19 pandemic has caused millions of deaths and great economic loss globally. There been substantial evidence supporting the airborne transmission SARS-CoV-2. Airborne route considered as a major pathway, which can spread disease over longer distance time. viral loads in respiratory tract virus carrier are typically below 109 RNA copies/mL related to emission rate pathogens. Most particles expelled during activities smaller than 1–2 µm diameter. Viral aerosols remain infectious for hours under typical indoor conditions. Sunlight contributes greatly viability inactivation outbreaks different scenarios reviewed based on existing data. were long-term care facilities, K-12 schools, restaurants, retail offices. Wells-Riley model estimating risk is introduced, along with parameters such quanta generation rate, virus-containing particle size distribution, rate. effectiveness various IAQ control strategies mitigating analyzed, including PPE, ventilation strategies, partitions, air cleaning, disinfection technologies, occupancy strategies. Both benefits costs should be designing
Язык: Английский
Процитировано
55
Indoor Air, Год журнала: 2021, Номер 32(1)
Опубликована: Ноя. 24, 2021
The evolution of SARS-CoV-2 virus has resulted in variants likely to be more readily transmitted through respiratory aerosols, underscoring the increased potential for indoor environmental controls mitigate risk.Use tight-fitting face masks trap infectious aerosol exhaled breath and reduce inhalation exposure contaminated air is critical importance disease control.Administrative including regulation occupancy interpersonal spacing are also important, while presenting social economic challenges.Indoor engineering ventilation, exhaust, flow control, filtration, disinfection by germicidal ultraviolet irradiation can reliance on stringent restrictions.However, effects controls-individually combination-on reducing transfer indoors remain clearly characterized extent needed support widespread implementation building operators.We review aerobiologic epidemiologic evidence against transmission present a quantitative scenario illustrating relative differences at close-interactive, room, scales.We identify an overarching need investment implement evaluate their effectiveness infection well-characterized real-world settings, supported specific, methodological advances.Improved understanding control guides scale considering occupant comfort, operational challenges, energy costs. Practical ImplicationsEmerging have led infectivity mode increasing incidence.Even absence symptoms, people infected with viruses exhale aerosols that inhaled, deposit tract, initiate infection.Indoor environments predominant settings because spend most time indoors, concentrations accumulate, resulting hazardous room (even distances much greater than two meters), illustrate these scales, provide overview scientific basis deployed buildings between people, outline priority research directions guide buildings.
Язык: Английский
Процитировано
46
International Journal of Environmental Research and Public Health, Год журнала: 2021, Номер 18(6), С. 3037 - 3037
Опубликована: Март 16, 2021
The dispersion of small aerosols in a concert hall is experimentally studied for estimating the risk infection with SARS-CoV-2 during concert. A mannequin was modified to emit an air stream containing and CO2. have size distribution peak diameter (δ) close 0.3 µm horizontal initial particle velocity (vp,x) 2.4 m/s. CO2-concentration (c) emitted simultaneously 7500 ppm. It investigated, if spatial dissipation CO2 can be correlated. This would allow use technically easier measurements monitor compliance aerosol concentration limits. Both concentrations are mapped by different sensors placed around mannequin. As result, no significant enrichment obtained outside radius 1.5 m when fresh ventilation has steady vertical flow vg,z=0.05 m/s installed system operating at change rate per hour (ACH) 3, corresponding exchange 51,000 m3/h. Pearson correlation coefficient 0.77 measured positions within hall.
Язык: Английский
Процитировано
45