Coronavirus: Wearing TWO masks block 20% more particles than one

Two masks may be better than one for preventing the spread of COVID-19, some scientists say. 

President-elect Joe Biden was ahead of the curve, wearing two masks on the campaign trail – a habit for which President Donald Trump mocked him.  

But Biden was on to something. Wearing a thicker fabric mask over a surgical one may act like a double-filter and improve the fit of face coverings, University of California, San Francisco, scientists advised in recent commentary. 

Double-masking may block more than 90 percent of infectious particles, the researchers found. 

It comes as public health officials warn that vaccines – which are being rolled out painfully slowly in the US – won’t mean we can take off our masks, because they don’t necessarily prevent people from spreading the virus. 

President-elect Joe Biden often wore two masks  on the  campaign trail and  was mo

‘Americans will not need to be wearing masks forever,’ Dr  Monica Gandhi, study co-author told the New York Times. 

But for the coming months, they’ll stay essential.  

A cloth or surgical mask on its own blocks about 70 percent of infectious particles we exhale. 

That’s not nearly as effective as an N95, which is named for its ability to contain 95 percent of these tiny droplets. 

When coronavirus first emerged at the end of 2019, officials in the US and even at the World Health Organization initially said anything less than an N95 mask wouldn’t do enough to be worth wearing, since the virus was not yet widespread. 

And they begged that N95s be reserved for health care workers who would have to be in contact with COVID-19 patients. 

But since their tune changed, masks have become the constant of public health messaging and daily life. 

For the most part, masks have not gotten any better, but with more than 23 million cases of COVI-19 in the US and more than 90 million worldwide, something is certainly better than nothing. 

Wearing  a cloth mask over a surgical one (bottom right) can  block more than 90%  of infectious particles, research suggests 

In their review of studies on mask efficacy, the UCSF ranked some face coverings as ‘basic,’ and others as giving ‘maximal protection.’ 

A mask with two layers of tightly woven fabric is basic, but its strength lies in fitting the face better, so infectious particles are less likely to travel around the sides, either out or in. 

Surgical masks provide better filtration, but they fit the face loosely, hampering their coverage. 

Wearing a cloth mask over a surgical one can give the best of both worlds. 

Or, you can purchase a tightly woven fabric mask that features a filter, for an all-in-one solution. 

There is, however, too much of a good thing. 

Two masks may be better than one, but three can be suffocating. 

Researchers warn that too many layers may make it too hard  to breathe for the face coverings to be worth it. 

But a pair approaches  the level of particle blockage offered by an N95.