A student adjusts her face mask at an exam hall in Seoul. (AFP / Kim Hong-ji)

Misleading face mask graphic shared in incorrect virus posts

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Multiple online posts have shared a graphic that purports to show the virus that causes Covid-19 is small enough to pass through certain face masks. The claim is misleading, according to health experts. The virus spreads as part of larger particles -- created by sneezing or coughing -- that are effectively blocked by face masks, they said.

The graphic was shared here on Facebook on September 3, 2020.

It purports to compare the size of the virus that causes Covid-19 with larger dust and aerosol particles.

It suggests the virus particles are small enough to pass through the fibres of KF94 masks.

KF94 masks are a type of face covering that provide more robust protection from fine particles compared to ordinary surgical masks, according to South Korea’s Ministry of Food and Drug Safety.

The post’s Korean-language caption translates to English as: “The size of the virus. How can we block a virus that is much, much smaller than fine dust particles? Don’t you think the government and experts know this? Thus Covid-19 mask rules are a scam".

Screenshot of the misleading Facebook post. Captured April 26, 2021.

An identical graphic was also shared here and here on Facebook; here on Twitter; and here on Naver Band, a popular social media application in South Korea.

The graphic also appeared in this YouTube video, which has been viewed more than 11,000 times. It makes a similar claim about masks.

The claim, however, is misleading.

Health experts say the virus is always bound to larger particles when it travels through the air.

These larger particles -- created by sneezing or coughing -- are large enough to be filtered by face masks, according to Jung Jae-hun, a professor of preventive medicine at the Gachon University College of Medicine and Science.

"Microscopic particles can be captured by an electrostatic filter in the mask", Jung told AFP in a phone interview on April 24, 2021. “If you are able to block droplets, you can stop the viruses [contained within them]".

To protect against Covid-19 infection, South Korea’s Ministry of Food and Drug Safety recommends the use of KF80 masks and above --  including KF94 masks -- in indoor areas or when people are in close contact with others.  

The World Health Organisation (WHO) says wearing face masks helps prevent the spread of Covid-19.

In the video advisory above, the WHO states: "Closed, crowded settings with poor ventilation can increase the risk of spreading Covid-19.

"When you’re indoors and you don’t know how the room is ventilated, wear a mask regardless of the distance from others."