Public space samples could reveal how coronavirus spreads in air

Woman riding on the metro wearing a facemask to avoid an infectious disease

Credit: andresr/GettyImages

A new study will explore whether tiny airborne droplets and particles can spread coronavirus in settings, such as supermarkets, schools and busy streets.

Researchers from Imperial College London and the University of Surrey will collect samples from a wide range of public spaces. The aim is to find out whether microscopic droplets suspended in the air from coughing or talking can spread ‘live’ COVID-19 virus.

Sites across London will be sampled, beginning with hospitals and then extending to, but not limited to:

  • schools
  • care homes
  • traffic intersections
  • train and tube stations.

The COVAIR study has been funded by the Engineering and Physical Sciences Research Council.

Airborne transmission of the virus

The SARS-CoV-2 virus can be dispersed by droplets released into the atmosphere through:

  • coughing
  • talking
  • normal breathing.

Research suggests that the smallest of these droplets can remain suspended in the air for hours. They also travel more than a few metres to land on surfaces, where they can persist for days.

There is a gap in our knowledge about the levels of ‘live’ or ‘viable’ virus circulating in the air that could potentially be inhaled and cause infection.

A new method

Several projects have used polymerase chain reaction to detect the presence of the virus in the air. However, that method cannot show whether the virus is still viable and able to cause infection.

The COVAIR researchers will transfer samples to a high containment laboratory to find out whether they can replicate viable virus. This is an indicator that it could cause infection in the lungs of the person inhaling the aerosol or particles.

Protective measures

Professor Fan Chung, Principal Investigator at Imperial College London, said:

COVAIR will look into whether the live virus can be transmitted through aerosols or pollutant particles in the air. It will build on the expertise we have developed in our current INHALE study at Imperial, which aims to assess the impact of air pollution on personal health in urban environments.

If we’re able to detect viable virus in the air it may have implications for additional protective measures that people would need to take in public spaces.

Read about the INHALE study.

Professor Chung added:

COVID-19 continues to have a major impact on the lives of everyone on the planet. It is therefore important to learn more about how we can protect ourselves from this deadly virus.

Last updated: 16 March 2021

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