Transcript for WHO acknowledges virus spread through smaller particles
President trump has officially taken steps to withdraw the U.S. From the world health organization today, but there was important news from that organization and it comes amid pressure from hundreds of scientists and doctors around the world, who believe that tiny virus particles can actually linger in the air far longer than many have acknowledged. And so ABC's Eva pilgrim tonight on just how long those particles could be in the air. Reporter: Tonight, the world health organization for the first time acknowledging it may be possible that covid-19 could spread through the air more easily than we knew. We acknowledge that there is emerging evidence in this field. Reporter: 239 scientists from 32 countries put pressure on the W.H.O to change its current guidance. We have long known that the virus can spread, as you see in this video, by large droplets that are only in the air for minutes. Those droplets can come from anything from talking loudly, singing, or even breathing heavily. Scientists say the virus may be able to stay in the air much longer in much smaller, tiny air sollized particles. Those particles could potentially get caught up in the circulation system of a room. Where the ventilation is poor and virus can build up, especially if there's lots of people in the room. Reporter: Look at this study out of China. A woman went to a restaurant before showing any symptoms. Less than two weeks later, nine other people got the virus. Five who were not seated at her table. Some of the people who got sick were more than 15 feet away. In Washington state, Tony Reyes was one of 14 customers testing positive after going to this east Vancouver bar. Four employees also sick. Eventually, they said, we need to move you to the icu. Don't be naive. This virus is no joke. Reporter: He's since recovered, but cases tied to restaurants and bars have pushed several cities and states to roll back openings at indoor businesses. Today, Dr. Anthony Fauci, the country's chief infectious did expert, says he thinks governors in states with surging cases should mandate masks to prevent outbreaks. Masking, distancing, washing hands, closing bars. If you do that, I think it will be a giant step towards interfering with the spread in your community. So, let's get right to Eva pilgrim tonight. And we just heard Dr. Fauci talking about the importance of wearing a mask. You spoke to one of the scientists raising the alarm with the world health organization. That scientist telling you, wear masks, even indoors. Reporter: Yes, David. And this is why. One study suggesting that these particles can linger in the air for as long as 16 hours in a lab setting. Drcht Fauci and Dr. Marr say this reiterates why it's so important to wear a mask, especially indoors, even when social distancing. David? And it just reminds us that there is still so much we don't know about this. Eva, thank you.
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