Understanding effects of ventilation on airborne microorganisms in build environments

A perspective

Abstract

The indoor air quality is associated with occupant productivity and a host of chronic health problems, including allergies, asthma, and depression. Ventilation is one of the solutions to improve air quality. Qualitative and quantitative characteristics of different ventilation systems, i.e., natural, mechanical and hybrid systems, might have an influence on several aspects of indoor environmental quality. As potential indoor pollutants, there are a great variety of components such as chemical substances and microbes, but our knowledge about the relationship between ventilation and microbes inhabiting the built environment is limited, including SARS-CoV-2. This limitation may partly be caused by the facts that i) methods, especially sampling of low concentration microbes from the air, for investigating indoor microbial community have not yet been established, ii) microbes in the built environment are greatly influenced by the surrounding environment and human lifestyle and behavior, and iii) different ventilation methods also affect the microbial community. The purpose of this study is to summarize the importance of airborne microorganisms in the built environment, focus on very different built environments with natural and mechanical ventilation, respectively, from a microbiological view, and attempt to find the characteristics of microbial communities in each environment. As a result, the possibilities and limitations of the current ventilation systems are highlighted, as well as tools and methods useful for analyzing airborne microbial communities, with preliminary results from our new-generation sequencer.