Fact Check-Study that found COVID-19 can be transmitted through aerosols doesn’t prove masks are ineffective

A social media post has claimed that a peer-reviewed study shows that masks do not protect you against COVID-19 because the virus can be transmitted in aerosol particles. This, however, is misleading.

The post (here) references a study titled: “Viral Load of SARS-CoV-2 in Respiratory Aerosols Emitted by COVID-19 Patients while Breathing, Talking, and Singing”, which found that aerosol transmission plays an important role in driving the COVID-19 pandemic.

Linking to the paper, the Twitter user writes: “New peer-reviewed research arguing COVID primarily spreads through aerosols and is airborne. If true, then your mask didn’t protect you but made you feel safe enough to be exposed without knowing it.”

While the study did find that virus particles spread as aerosols, it also advocates for continued mask wearing.

In the study itself, the researchers concluded that the results supported “calls for proper respiratory protection” in the form of both “universal masking” and N95 and FFP3 respirators for healthcare and frontline workers (here).

And replying to a now-deleted tweet which concluded that since “masks can block droplets, not aerosols”, the paper proves that it was time to abolish all “non-scientific mask mandates”, the study’s lead author reiterated that the results do in fact “support the calls for universal masking” (here).

The U.S. Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) both advise that masks should be worn to help reduce the spread of COVID-19(here , here).

Studies (here , here , here) have shown that masks do help block aerosols - though the extent they do so depends on the type of mask.

As this CDC graphic explains (here), the N95 mask filters out at least 95% of airborne particles, both large and small.

Meanwhile, a surgical mask doesn’t offer much protection for the wearer, but is designed instead to protect others against virus particles that are exhaled (here).


Misleading. While the study did find that SARS-CoV-2 spreads as aerosols, this does not mean masks are an ineffective tool in managing the pandemic. A surgical mask is designed instead to protect others against virus particles that are breathed out, while respiratory masks such as the N95 do filter out airborne particles.

This article was produced by the Reuters Fact Check team. Read more about our work to fact-check social media posts here .