Covid-19 airborne particles can travel about 200 feet

Small coronavirus respiratory particles are likely to remain airborne for a longer time and also travel further than what was previously assumed. A recent study published in the journal International Communications in Heat and Mass Transfer has shown that the tiny droplets could remain moist for up to 30 minutes and travel up to about 200 feet.

Previously, it was assumed that very small, aerosolised droplets of just a few microns, like those produced in the lungs, dry out in air almost instantly, becoming harmless. But the study proves otherwise. For this, the researchers took a long look at the mucus that coats the respiratory droplets that people spew from their lungs.

The researchers from the US Department of Energy’s Pacific Northwest National Laboratory (PNNL) noted that mucus allows many viruses to travel further, enabling them to journey from one person to another.

Reasoning this, the scientist said that this is because enveloped viruses like SARS-CoV-2 have a fatty coating that must be kept moist for the virus to be infectious, the slower evaporation allows viral particles to be infectious longer.

“There are reports of people becoming infected with a coronavirus downwind of an infected person or in a room several minutes after an infected person has exited that room,” said Leonard Pease, the corresponding author of the study.

“The idea that enveloped virions may remain well hydrated and thus fully infective at substantial distances is consistent with real-world observations. Perhaps infectious respiratory droplets persist longer than we have realised,” Pease added.

The researchers noted that while there have been many factors proposed as variables in how COVID spreads, mucus remains largely overlooked. LiveMint