Medical Research Council - London Institute of Medical Sciences

Now in our 11th year of bringing you beautiful imagery from biomedical science every day

Wearing a mask drastically reduces saliva droplet propagation

26 August 2021

Short of Breath

They are a simple symbol of the pandemic that has overwhelmed the world. Face masks, unavoidable from supermarkets to subways, have become everyday essentials. But they remain controversial to some, and as regulations tighten and relax in different countries, their importance will continue to be questioned. Improved understanding of their effectiveness helps individuals and governments to make decisions, so a new study used computer simulations with updated parameters to realistically estimate the distance water droplets capable of carrying virus particles travel during normal human breathing without (start of the video) and with (end of video) a mask. The simulations suggest that without a mask, saliva droplets travel up to 2.2 metres in 90 seconds, compared to just 0.72 metres in 2 minutes from a masked person. The study also assessed the complex vortex rings and aerodynamics behind the breath-powered propulsion, helping further unmask the mystery of mask effectiveness.

Written by Anthony Lewis

Search The Archive

Submit An Image

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.