A recent study (25/10/23) by researchers at the University of Tsukuba examined how the risk of COVID-19 infection changes based on exposure time when passing an infected person. They sought to identify effective measures to reduce transmission risks during movement.
Using a mannequin emitting simulated viral particles, they measured particle levels at different movement speeds – walking, jogging, running, sprinting – with and without ventilation. The number of particles peaked within 5 seconds of passing in all scenarios before sharply dropping.
Faster movement speeds resulted in lower peak particle counts, likely due to increased diffusion from the vortex created by movement. With ventilation, the peaks were 55% or less of those without ventilation.
The findings indicate measures like briefly holding your breath, keeping 1 meter distance, and proper ventilation within 5 seconds of passing an infected person can significantly reduce infection risks. After 5 seconds, risks drop sharply as particles diffuse.
The researchers conclude simple preventive steps focused on the short period of peak exposure risk can help cut transmission when people are moving around based on this evidence. Their study provides data to guide public health policies on mobile social interactions.
You can read the full article here.