Covid-19: new study reveals how and how much to wash your hands, and it is less than previously believed

08/17/2021 3:49 PM

• Clarín.com

• Dresses

Updated 08/17/2021 3:49 PM

After a year and a half of pandemic, everything has been said about the prevention that people must have to try to avoid the spread of coronavirus.

One thing is for sure: it is one of the main actions that we can all take to try to keep the virus out of our body.

But

what is good hand washing?

There are many points to take into account, but surely the way you do it is not enough to eliminate all the germs.

According to the World Health Organization, hand hygiene has scientific evidence in the prevention and control of infections.

Although this wash is only effective if it is done with

plenty of soap and water

(although gel alcohol is also accepted).

However, in recent months the issue of how it is convenient to sanitize the hands has also been debated.

Now, the English mathematical expert

Paul Hammond, 

created a model to explore

how the physics of hand washing works.

Frequent and vigorous hand washing is one of the most common prevention methods.

Hammond said that the effectiveness of hand washing is related to how hard you scrub, but that the process still takes time even when done correctly.

Until now it was said that the ideal

was to wash your hands between 40 and 60 seconds

, but Hammond's research concludes otherwise.

Hammond's two-dimensional model considers hands on

a microscopic scale

, depicting the roughness of the skin as a pair of wavy surfaces, separated by a thin film of liquid, that move side by side when scrubbed, the

Daily Mail

reports

. 

Particles such as bacteria and viruses end up trapped in the valleys of these surfaces, that is, the

lines and folds of the hands

.

This is what Hammond calls 'potential wells'.

Given this, in order for particles like bacteria and viruses to be dislodged from a hand during washing, the

jet of water must be strong enough

to move up and out of those valleys.

The model revealed that the strength of this flow

depends on the speed at which you rub your hands.

Specifically,

more vigorous movements

remove particles more easily.

"Basically the flow tells you about the forces on the particles," he said, who runs a scientific consulting firm based in Bourn, near Cambourne, UK.

"Then you can find out how the particles are moving and find out if they are removed."

When it comes to making sure your hands are clean, the mathematician explained, the process is a lot like

cleaning a stain on a shirt.

It all begins by scrubbing the palms of the hands well, until the soap foams and covers the entire area. Then

, you have to pass the soap between the fingers

and the outer side of the hands. The next step is to scrub the tips of the fingers against the palms of each hand.

The thumbs should also be specially washed

, the method emphasizes inserting them into the closed palms of the hands. The soap part ends with a review of the wrists. Now the water kicks in. How long does it take for the soap and germs to go with the liquid?

As much as singing "Happy Birthday" twice.

Finally, the Hammond model indicates that it takes at least 

20 seconds

of strong action to kill all potential bacteria and viruses.