Airborne Transmission of SARS-CoV-2: The Contrast between Indoors and Outdoors

Published: Jan. 11, 2024

Covid-19 is an airborne disease, with the vast majority of infections occurring indoors. By comparison, little transmission occurs outdoors. Here, we investigate pathways that differentiate indoors from outdoors, and conclude profound differences exist, which help to explain why SARS-CoV-2 much more prevalent Near far-field are discussed along factors affect infection risk, aerosol concentration, air entrainment, thermal plumes, occupancy duration all identified as being influential. In particular, present fundamental equations underpin Wells-Riley model, show mathematical relationship between inhaled virus particles quanta infection. A simple model also presented for assessing risk in spaces incomplete mixing. Transmission assessed terms concentration using 1D equations, followed by a description plume-ceiling interactions. With respect this, new experimental results Schlieren-visualisation Computational Fluid Dynamics (CFD) based on Eulerian-Lagrangian approach. Pathways discussed, key contribution exhalation plumes evaluated, presence near-field/far-field feedback loop postulated, absent

Language: Английский

Indoor Air Quality Control for Airborne Diseases: A Review on Portable UV Air Purifiers

Fluids, Journal Year: 2024, Volume and Issue: 9(12), P. 281 - 281

Published: Nov. 26, 2024

The spread of airborne diseases such as COVID-19 underscores the need for effective indoor air quality control. This review focuses on ventilation strategies and portable purifiers key mitigation solutions. Ventilation systems, including natural mechanical approaches, can reduce pathogen concentrations by improving airflow. However, combining with purifiers, particularly those using HEPA filters, ESP UV-C radiation, enhance Indoor quality. While filters focus trapping particles, radiation inactivate pathogens disrupting their RNA. A UV reveals a lack studies efficacy effectiveness in real-world settings. thorough investigation into performance this solution is necessary, focusing varying factors, purifier placement, airflow dynamics, dosage, to ensure optimal effectiveness. High-fidelity computational methods are essential accurately assessing these informed physics transmission. Such advanced computations necessary determine viability mitigating transmission enclosed environments hospitals public spaces. Integrating purification technologies proper improve safety prevent future disease-related outbreaks.

Language: Английский