Do masks work? And if so, should you reach for an N95, a surgical mask, a cloth mask or a gaiter?
Over the past year and a half, researchers have produced a lot of laboratory, model-based and observational evidence on the effectiveness of masks. For many people it has understandably been hard to keep track of what works and what doesn’t.
I’m an assistant professor of environmental health sciences. I, too, have wondered about the answers to these questions, and earlier this year I led a study that examined the research about which materials are best.
Recently, I was part of the largest randomized controlled trial to date testing the effectiveness of mask-wearing. The study has yet to be peer reviewed but has been well received by the medical community. What we found provides gold-standard evidence that confirms previous research: Wearing masks, particularly surgical masks, prevents COVID-19.
Lab and observational studies
People have been using masks to protect themselves from contracting diseasessince the Manchurian outbreak of plague in 1910.
During the coronavirus pandemic, the focus has been on masks as a way of preventing infected persons from contaminating the air around them – called source control. Recent laboratory evidence supports this idea. In April 2020, researchers showed that people infected with a coronavirus – but not SARS-CoV-2 – exhaled less coronavirus RNA into the air around them if they wore a mask. A number of additional laboratory studies have also supported the efficacy of masks.
Out in the real world, many epidemiologists have examined the impact of masking and mask policies to see if masks help slow the spread of COVID-19. One observational study – meaning it was not a controlled study with people wearing or not wearing masks – published in late 2020 looked at demographics, testing, lockdowns and mask-wearing in 196 countries. The researchers found that after controlling for other factors, countries with cultural norms or policies that supported mask-wearing saw weekly per capita coronavirus mortality increase 16% during outbreaks, compared with a 62% weekly increase in countries without mask-wearing norms.
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Source: The Conversation
Date: 8 October