COVID-19 and the built environment

April 10, 2020

Social distancing has Americans mostly out of the places they usually gather and in their homes as we try to reduce the spread of COVID-19. But some buildings, such as hospitals and grocery stores, have to remain open, and at some point, most of us will go back to the office or workplace. What is the role of building design in disease transmission, and can we change how we design the built environment to make it healthier? Those questions are addressed in a review just published in the journal mSystems by David Coil, project scientist, and Professor Jonathan Eisen at the UC Davis Genome Center and School of Medicine; and colleagues at the Biology and the Built Environment Center, University of Oregon.

Among the simplest suggestions for healthier buildings: opening windows to improve air circulation and opening blinds to admit natural daylight.

While more research needs to be done on the effect of sunlight on SARS-CoV-2 indoors, "Daylight exists as a free, widely available resource to building occupants with little downside to its use and many documented positive human health benefits," the authors write.

We spend almost all of our daily lives inside human-built environments whether homes, vehicles or workplaces. Built environments provide lots of opportunities for people to come into contact with viruses and bacteria -- through air flow, from surfaces and also from the way buildings make us interact with each other.

So far, the only documented route of transmission of SARS-CoV-2 is directly from person to person. But viruses also settle on surfaces, which can become heavily contaminated quite quickly. How long SARS-CoV-2 survives on surfaces is still up for debate. Estimates range from a couple of hours to a few days, depending on the material and conditions. Regularly cleaning surfaces and thorough handwashing are important.

Air flow and humidity

Viral particles are too small to be blocked by HEPA and MERV air filters, but ventilation strategies can still play a role in reducing disease transmission, the authors write. Increasing the amount of air flowing in from outside and the rate of air exchange can dilute virus particles indoors. This can include "perimeter ventilation" -- opening a window, when outdoor temperatures allow it. However, high air flow could also stir up settled particles and put them back in the air -- and it also uses more energy.

Virus particles like drier air, so maintaining a high relative humidity can help. Virus-bearing droplets get bigger in humid air, meaning they settle out more quickly and don't travel as far. Humidity also seems to interfere with the lipid envelope around viruses such as SARS-CoV-2. Too much humidity, however, can promote mold growth.

Modern buildings are generally designed to promote social mixing -- from open plan living areas in homes to open offices where many workers share space. By promoting interaction and chance encounters, these layouts are thought to generate more creativity and teamwork. At the same time, they are probably also really great for spreading viruses around.

It may not be practical in the short term to make big changes in office layout. But understanding how layout and the ways people use shared spaces affect disease transmission could help in developing effective social distancing measures and making decisions about when people can go back to work.
-end-
Eisen holds appointments in the Department of Evolution and Ecology, College of Biological Sciences, and the Department of Microbiology and Immunology, School of Medicine, at the University of California, Davis. Co-authors on the review are Leslie Dietz, Patrick Horve, Mark Fretz and Kevin Van Den Wymelenberg at the Biology and the Built Environment Center, University of Oregon.

University of California - Davis

Related Viruses Articles from Brightsurf:

Sorting out viruses with machine learning
Researchers at Osaka University created a machine-learning system to identify single viral particles that cause respiratory diseases, including coronavirus, using silicon nanopores.

The rafts used by viruses
The study may suggest new strategies to limit virus attacks and prevent or combat diseases like Sars and Covid-19 based on biomedical and engineering principles.

Animals keep viruses in the sea in balance
A variety of sea animals can take up virus particles while filtering seawater for oxygen and food.

Hundreds of novel viruses discovered in insects
New viruses which cause diseases often come from animals. Well-known examples of this are the Zika virus transmitted by mosquitoes, bird flu viruses, as well as the MERS virus which is associated with camels.

First video of viruses assembling
For the first time, researchers have captured images of the formation of individual viruses, offering a real-time view into the kinetics of viral assembly.

Plant viruses may be reshaping our world
A new review article appearing in the journal Nature Reviews Microbiology highlights the evolution and ecology of plant viruses.

Checkmate for hepatitis B viruses in the liver
Researchers at Helmholtz Zentrum M√ľnchen and the Technical University of Munich, working in collaboration with researchers at the University Medical Center Hamburg-Eppendorf and the University Hospital Heidelberg, have for the first time succeeded in conquering a chronic infection with the hepatitis B virus in a mouse model.

How viruses outsmart their host cells
Viruses depend on host cells for replication, but how does a virus induce its host to transcribe its own genetic information alongside that of the virus, thus producing daughter viruses?

Mobile, instant diagnosis of viruses
In a first for plant virology, a team from CIRAD recently used nanopore technology to sequence the entire genomes of two yam RNA viruses.

How ancient viruses got cannabis high
THC and CBD, bioactive substances produced by cannabis and sought by medical patients and recreational users, sprung to life thanks to ancient colonization of the plant's genome by viruses, U of T researchers have found.

Read More: Viruses News and Viruses Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.