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Airborne spread of expiratory droplet nuclei between the occupants of indoor environments: A review
Author(s) -
Ai Z. T.,
Melikov A. K.
Publication year - 2018
Publication title -
indoor air
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.387
H-Index - 99
eISSN - 1600-0668
pISSN - 0905-6947
DOI - 10.1111/ina.12465
Subject(s) - computational fluid dynamics , environmental science , airflow , indoor air , airborne transmission , aerospace engineering , marine engineering , instrumentation (computer programming) , transmission (telecommunications) , boundary (topology) , computer science , simulation , meteorology , engineering , mechanical engineering , environmental engineering , physics , covid-19 , telecommunications , mathematics , medicine , mathematical analysis , disease , pathology , infectious disease (medical specialty) , operating system
This article reviews past studies of airborne transmission between occupants in indoor environments, focusing on the spread of expiratory droplet nuclei from mouth/nose to mouth/nose for non‐specific diseases. Special attention is paid to summarizing what is known about the influential factors, the inappropriate simplifications of the thermofluid boundary conditions of thermal manikins, the challenges facing the available experimental techniques, and the limitations of available evaluation methods. Secondary issues are highlighted, and some new ways to improve our understanding of airborne transmission indoors are provided. The characteristics of airborne spread of expiratory droplet nuclei between occupants, which are influenced correlatively by both environmental and personal factors, were widely revealed under steady‐state conditions. Owing to the different boundary conditions used, some inconsistent findings on specific influential factors have been published. The available instrumentation was too slow to provide accurate concentration profiles for time‐dependent evaluations of events with obvious time characteristics, while computational fluid dynamics ( CFD ) studies were mainly performed in the framework of inherently steady Reynolds‐averaged Navier‐Stokes modeling. Future research needs in 3 areas are identified: the importance of the direction of indoor airflow patterns, the dynamics of airborne transmission, and the application of CFD simulations.