Air transmission of Covid-19 is being underestimated - which could impact guidelines on social distancing, ventilation systems and shared spaces, warns new research.
Researchers at Heriot-Wyatt University and University of Edinburgh found evidence that both small and large droplets can travel relatively long distances through the air - and not always in predictable directions with airflow.
The World Health Organisation (WHO) warned aerosol transmission of Covid-19 is being underestimated as a study reveals droplet spread from humans does not always follow airflow.
Researchers say the new findings on droplet migration may have important implications for understanding the spread of airborne diseases such as COVID-19.
It comes after top US infectious disease specialist Dr Anthony Fauci admitted during a Monday JAMA interview that there is much unknown about how coronavirus spreads through the air and that he himself needs to 'study' papers that suggest big droplets can travel further than six feet.
Scientists of the study at Heriot-Watt University and the University of Edinburgh in Scotland echoed his sentiments that a better understanding of different droplet behaviors and their spread based on droplet size is also needed.
Scientists in the UK found that both small and large droplets from people coughing or just breathing can travel far distances and unpredictable directions, suggesting the airborne danger of coronavirus - but they invented a device to 'extract' tiny infectious particles not stopped by masks from the air (file)
Government guidelines will need to be considered if air transmission is proven to be significant.
Dr Cathal Cummins, an assistant professor at Heriot-Watt University in Edinburgh, said: 'The flow physics of someone coughing is complex, involving turbulent jets and droplet evaporation.
'And the rise of Covid-19 has revealed the gaps in our knowledge of the physics of transmission and mitigation strategies.'
One such gap in the physics is a clear, simple description of where individual droplets go when ejected.
Dr Cummins added: 'We wanted to develop a mathematical model of someone breathing that could be explored analytically to examine the dominant physics at play.'
The team created a mathematical model that clearly shows small, intermediate and large-sized droplets.
They found simple formulas can be used to determine a droplet's maximum range.
This has important implications for