Transcript for Experts warn of possible risks with indoor gatherings for holidays
Thanks very much. We'll look ahead to the pandemic's impact on the holidays. Experts are warning about the risk of gathering friends and family indoors for Thanksgiving and Christmas and Dr. Ashish jha is Stange by with his advice on how to minimize the risk after this report from Becky Worley. Reporter: Outdoor, it's where experts have been urging us to go with small groups. But what happens when it's freezing outside? I do really recommend that people stay away from indoor gatherings. Reporter: The CDC recently updated its guidance saying the virus can spread in small droplets that linger in the air potentially for hours and another of their reports shows how dangerous that can be it details 20 relatives who attended a family gathering over a three-week period including a teen who unknowingly brought the virus with her. All but two of the 14 who shared the shouse contracted covid. Six only visited for a few hours mostly remaining outdoors and left not infected. So when it comes to being indoors with people from outside your household. If it's something that you can't imagine not doing, then you need to prepare for at least two weeks in advance for everybody in that gathering to essentially be quarantined. Reporter: Experts say wearing masks and socially distancing are key but another important factor, reducing the amount of virus particles that could be in the air. Air circulation is critically important. We've learned from increasing evidence that air transmission is more effective for this virus than we originally thought. Reporter: So how do you improve air circulation indoors? First with outside fresh air. Through an open window. That air diluting particles in the air. Second option with air that's been run through the filters in your heating system. Experts say dirty filters aren't as effective at getting rid of particles so change out your filter now. Plus, that's gross. While finer filters like those rated merv 13 are more effective not all heaters can handle the workload of a finer filter so check your system specs or call your hvac guy. Air purifiers. The simplest I'm recommending are things called Hepa filtration and efficient at removing particles of the size we care about and readily available in the market. Reporter: You have to make sure to buy the appropriate size air purifier for your space. All are layers of air improvement but no magic bullet to make indoor gatherings for "Good morning America," Becky Worley, ABC news, Oakland, California. And joining us now is Dr. Ashish jha, the Dean of the browning university school of public health. Dr. Jha, thanks for being with us. We saw this virus surge after recent holidays but those were all in warmer months where people were mostly outdoors. Now we're going to see Thanksgiving and Christmas where people tend to be inside. What are you anticipating? Good morning. Thank you for having me on. First of all I think it's really frustrating this is where we are as a country. Going into the holiday season, we could have really suppressed this virus and we haven't and so I am very worried about what's going to happen. What we know is that when large numbers of people gather, especially indoors the virus tends to spread very efficiently as we saw in that report. We have seen it after every holiday. I'm worried we'll see more after Thanksgiving and Christmas. Is there a safe number people can keep their indoor activities to in terms of people inside their home? Yeah, so there's no single magical number. If you want 100% safety, unfortunately that means not seeing anybody outside of your household. That's pretty tough both for Thanksgiving and for the holidays. And so as we heard in that report, if you want to see other family members, there's a set of steps you can take from really keeping yourself quarantined for a couple of weeks going in, limiting the number of people working on ventilation inside, it's not going to be an easy holiday season. We heard in Becky's report that, yes, keeping the air circulating, having air purifiers may help. What about H umidifiers what do we know about that? Yes, well, we know that the virus does spread more efficiently in colder, drier air. We haven't seen any data that putting in humidifiers lowers that spread. I mean in some ways it stands to reason it would. But we haven't seen that data or at least I haven't seen that data. What I've been recommending to people is obviously try to keep a level of humidity in your home that's reasonable and will let you be comfortable. But it's really about air -- sort of the freshness of the air. That's much more important, I think, than the humidity per se. Well, Dr. Jha, we certainly appreciate your expertise and time this morning. Thank you for being with us. Thank you. For more tips on how to stay safe and healthy with company during the holidays visit goodmorningamerica.com. Coming up next here an ABC news exclusive with the author
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