Dean Blumberg, chief of pediatric infectious diseases at the University of California, Davis Children’s Hospital says that a range of new research on face coverings shows that the risk of infection to the wearer decreases by 65%.
Wearing a mask helps to protect you and others from the spread of COVID-19, which is primarily transmitted by droplets.
Face coverings reduce the risk of infection by 65%, according to research.
Aerosol particles we expel when we talk are the second major mode of transmission – and are more difficult to defend against.
A report by Michael Klompas, MD, MPH, Meghan A. Baker, MD, ScD and Chanu Rhee, MD, MPH looking into studies of airborne transmission of SARS-CoV-2 concludes that although there are rarely absolutes in biological systems, the current evidence indicates that “long-range aerosol-based transmission is not the dominant mode of SARS-CoV-2 transmission.“
“All told, current understanding about SARS-CoV-2 transmission is still limited. There are no perfect experimental data proving or disproving droplet vs aerosol-based transmission of SARS-CoV-2. The balance of evidence, however, seems inconsistent with aerosol-based transmission of SARS-CoV-2 particularly in well-ventilated spaces.
What this means in practice is that keeping 6-feet apart from other people and wearing medical masks, high-quality cloth masks, or face shields when it is not possible to be 6-feet apart (for both source control and respiratory protection) should be adequate to minimize the spread of SARS-CoV-2 (in addition to frequent hand hygiene, environmental cleaning, and optimizing indoor ventilation).”
The BBC have summarised the recent shift in political opinion on mask wearing. Although titled around the world, it is essentially about the u-turn that Trump and Johnson have had to enact in the face of the overwhelming evidence that their previous stance against masks would be too costly in terms of economics, votes and lives.
“It used to be quite normal to have quite a few drinks and drive home, and it also used to be normal to drive without seatbelts. Today both of those would be considered antisocial, and not wearing face coverings in public should be regarded in the same way. If all of us wear one, we protect each other and thereby ourselves, reducing transmission.”
In a strongly worded editorial piece, the Washington Post has come out clearly on the side of mask wearing, going so far as to call out Trump on his stance against masks.
Covid-19 is not a “political controversy,” and combating it is not a matter of customer relations. It’s a public health crisis, and defeating it requires heeding public health experts. That means wearing masks in public; increased testing and tracing; and isolating people who become infected.
They are now recommending that non-medical masks should be worn where there is widespread transmission and when physical distancing is difficult, such as on public transport, in shops or in other confined or crowded environments.
There still seems to be concern that encouraging the public to wear masks will also encourage the public to behave irresponsibly:
“I cannot say this clearly enough,” said the Director-General. “Masks alone will not protect you from COVID-19.”
The article explains that the current 2 metre social distancing rule is based on studies into how far respiratory droplets travel from the mouth. But these studies were carried out in the 1930s and focused on relatively large, heavy droplets that fall to the ground in a few seconds. Scientists can now detect much smaller droplets that can stay airborne for up to 12 hours while following airflows and potentially reaching much further than 2 metres.
As the picture so graphically illustrates, masks can play a key role in reducing the quantity of airborne droplets expelled by the infected, while simultaneously reducing the exposure of the healthy.
It’s a clear win/win situation from a science perspective.