Should we wear a mask on the street? Why? | Coronavirus

Portugal recommends wearing a mask in crowded public spaces

In Portugal, the use of a mask is recommended both in open and closed spaces “as long as the minimum physical distance of two meters is not guaranteed,” reads the country’s Autumn-Winter Health Plan. The recommendation was announced by the General Directorate of Health (DGS). In closed public spaces, the use of a mask is mandatory for all people over ten years of age. In August, DGS said that wearing masks in public places would have to be “proportional to risk” and that it should be a matter of “common sense.”

“There are public spaces that are served by several people at the same time that can be treated in a wide and open public space, we have to be aware of the risk. Going to a busy street in a city is different than walking the dog at ten o’clock at night on a non-busy street. We have to have that common sense and proportionality ”.
Graça Freitas, General Director of Health
August 28, 2020

What should be considered when analyzing the use of a mask?

Exposure risk

What is the level of contagion in the country and what is the exposure of each person?

Vulnerability

Elderly people or health complications should always wear a mask.

Population density

People who live in crowded places or in places where it is impossible to keep a safe distance should wear a mask.

Feasibility

What is the availability and price of the masks? Is there easy access to water to wash cloth masks?

Mask types

Surgical masks and respirators should be given priority to healthcare professionals, caregivers, and people with symptoms. WHO recommends the use of fabric masks with multiple layers (at least three), which also act as a barrier to drops.

Droplet and aerosol transmission

Simply speak or breathe to emit tiny droplets that can transmit the virus. Coughing and sneezing also cause the release of respiratory secretions – tiny droplets – and the viral load in the respiratory tract of an infected person is known to be high, so the possibility of “emission of contaminated secretions” is also high.
Depending on their size and weight, these droplets can be considered aerosols (droplets <10 µm), very small particles that hang in the air.

On average, how many microdroplets do we emit?

Talking one second,ten microdroplets

In a conversation ten minutes 6000 microdroplets

Cough: 3000 drops – can make horizontal trajectories of up to about two meters

Sneeze: up 40,000 drops, leaving microdroplets in the air that can travel up to six meters

What should I do if I don’t wear a mask on the street?

Masks can give a false sense of security to those who wear them, leading the person to not comply with social distance or hand hygiene because they believe they are protected, warns the World Health Organization. Masks alone do not protect against covid-19: “People should also wash their hands frequently and maintain a social distance of at least one meter.”
Even if wearing a mask is not mandatory in public outdoor spaces, there is a set of rules that you should always follow:

Maintain social distance

Wash (with soap) or sanitize your hands often

Cough and sneeze into the flexion of the elbow, not into the hand, and avoid touching your eyes, nose, and mouth.

And the visors?

The visors serve mainly to protect the eyes and also serve as a barrier to projected drops, but they open at the bottom and allow the aerosols to circulate. DGS had already warned that the visors do not dispense with the use of masks and that they must be used with another “barrier method” that allows the mouth and nose to be covered. A Japanese simulation (using the Fugaku supercomputer) showed that almost 100% of the smallest droplets escaped from the scopes

Restrictions on the use of masks in Europe

The use of a mask on public roads was already recommended in places like Arruda dos Vinhos or Guimarães; even so, there is no obligation to wear a mask outdoors in Portugal.