No safe spots from COVID-19 on trains

The team from Cambridge University and Imperial College London developed a mathematical model to help predict the risk of disease transmission, which was validated with a controlled experiment in a real train carriage. The team’s findings also show that masks are more effective than social distancing at reducing transmission, particularly in trains not ventilated with fresh air.

The research, reported in Indoor Air, shows how challenging it is to for individuals to calculate absolute risk, and how important it is for train operators to improve their ventilation systems to help keep passengers safe.

COVID-19 restrictions have been lifted in the UK, but the government continues to highlight the importance of good ventilation in reducing the risk of transmitting the disease, as well as other respiratory infections such as influenza.

“In order to improve ventilation systems, it’s important to understand how airborne diseases spread in certain scenarios, but most models are very basic and can’t make good predictions,” said first author Rick de Kreij, who completed the research while based at Cambridge’s Department of Applied Mathematics and Theoretical Physics. “Most simple models assume the air is fully mixed, but that’s not how it works in real life.