August 2, 2021

expert reaction to report on detecting SARS-CoV-2 in railway stations, commissioned by Network Rail

A study commissioned by Network Rail looked for traces of SARS-CoV-2 by swabbing places passengers touch regularly like escalator handrails, ticket machines, and benches, and taking hour-long air samples on station concourses at four major railway stations.

Professor Cath Noakes, Professor of Environmental Engineering for Buildings at the University of Leeds and a member of SAGE, said:

“It is good news that sampling has not identified virus, and this confirms other studies that have also shown that there is not widespread contamination persisting in the environment.

“However, it is important to remember that sampling can only measure a very small part of the environment and it is a snapshot in time. This is particularly the case with air sampling, which will only be able to detect virus when an infected person is present at the time the sample is taken or very shortly before. The chances that the sample is taken at exactly the right moment and location to find virus in the air is therefore very small.

“Virus in the air can be removed quickly when ventilation is good. Ventilation rates on mainline trains are typically around eight air changes per hour, which means that once an infected person had left, the virus in the air would be reduced to undetectable levels in under 30 minutes. Station concourses are very large spaces which will also act to dilute any virus in the air to low levels. Mask wearing on public transport is also likely to be beneficial in reducing environmental contamination as this will significantly reduce the chance that virus is emitted into the air as well as stopping the larger droplets that land on surfaces.

“Transmission can happen anywhere where people interact together including homes, workplaces, social settings and on transport and so it is important that we continue to make sure we ventilate spaces well, wear masks when in crowded indoor settings, maintain good hand hygiene and stay home and get a test if you have any symptoms.”

Press release from Network Rail – https://www.networkrail.co.uk/news/tests-show-no-traces-of-covid-19-at-four-major-railway-stations/

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