Better ventilation systems in indoor settings can help reduce the spread of COVID-19, new study results confirm, making the case for more decisive action, a public health scientist says.

Risk of SARS-CoV2 transmission, commonly known as COVID-19, is greatest when people are in close proximity, which is generally considered two meters, or about six feet, apart. But a new study conducted by UK researchers suggests that the potential for long-distance transmission of COVID – greater than 2 meters – is possible in indoor settings. 

The researchers, led by Daphne Duval of the UK Health Security Agency, evaluated 22 reports related to 18 studies of COVID outbreak investigations that occurred in indoor environments in the United States, Europe, Asia and Oceania. 

After considering previous outbreaks, the study found that several factors can contribute to long-distance transmission. They include insufficient air replacement and directional air flow that allows the virus to travel in a certain direction. Study authors indicated the research suggests improved ventilation can reduce the risk of long-distance transmission. 

A related editorial written by Stephanie J. Dancer, a consultant microbiologist with the NHS Lanarkshire, said the research “validates the premise that tiny respiratory particles containing SARS-CoV-2 freely transmit throughout inadequately ventilated environments.” 

“Now is indeed the time for an indoor air revolution,” she wrote.

Both the study and editorial appeared in the June 29 issue of the BMJ medical journal.