Research on how well various types of masks and face coverings varies but, recently, and in light of the pandemic of COVID-19, experts are increasingly leaning toward the notion that something is better than nothing.
A University of Oxford study published on March 30 concluded that surgical masks are just as effective at preventing respiratory infections as N95 masks for doctors, nurses and other health care workers.
It’s too early for their to be reliable data on how well they prevent infection with COVID-19, but the study found the thinner, cheaper masks do work in flu outbreaks.
The difference between surgical or face masks and N95 masks lies in the size of particles that can – and more importantly, can’t – get though the materials.
N95 respirators are made of thick, tightly woven and molded material that fits tightly over the face and can stop 95 percent of all airborne particles, while surgical masks are thinner, fit more loosely, and more porous.
This makes surgical masks much more comfortable to breathe and work in, but less effective at stopping small particles from entering your mouth and nose.
Droplets of saliva and mucous from coughs and sneezes are very small, and viral particles themselves are particularly tiny – in fact, they’re about 20-times smaller than bacteria.
For this reason, a JAMA study published this month still contended that people without symptoms should not wear surgical masks, because there is not proof the gear will protect them from infection – although they may keep people who are coughing and sneezing from infecting others.
But the Oxford analysis of past studies- which has not yet been peer reviewed – found that surgical masks were worth wearing and didn’t provide statistically less protection than N95 for health care workers around flu patients.
However, any face mask is only as good as other health and hygiene practices. Experts universally agree that there’s simply no replacement for thorough, frequent hand-washing for preventing disease transmission.
Some think the masks may also help to ‘train’ people not to touch their faces, while others argue that the unfamiliar garment will just make people do it more, actually raising infection risks.
So what about cloth coverings? Although good quality evidence is lacking, some data suggest that cloth masks may be only marginally (15 per cent) less effective than surgical masks in blocking emission of particles, said Babak Javid, principal investigator at Cambridge University Hospitals wrote in the BMJ on April 9.
He pointed to a study led by Public Health England in 2013 which found wearing some kind of material over the face was fivefold more effective than not wearing masks for preventing a flu pandemic.
The study suggested that a homemade mask ‘should only be considered as a last resort to prevent droplet transmission from infected individuals, but it would be better than no protection’.