It’s official: “substantial probability that normal speaking causes airborne virus transmission in confined environments.” 1 minute of talking loudly can produce more than 1,000 virus-containing droplets that could linger in the air for over 8 minutes. https://www.usatoday.com/story/news/nation/2020/05/13/closed-environments-high-risk-coronavirus-infections/5186862002/">https://www.usatoday.com/story/new...
Here’s the paper behind the headline: https://www.pnas.org/content/early/2020/05/12/2006874117">https://www.pnas.org/content/e...
The authors suggest that loud speech in a closed room (“stagnant airflow”) will produce droplets that can linger as long as 8-14 minutes. This could be one of the reasons for substantial spread of COVID-19, esp combined with asymptomatic or presymptomatic shedding.
It also supports signs in many parks (esp here in NY State) telling us to use the park for exercise/dog walking, not stopping & chatting. Yes it’s outdoors but just speaking loudly is riskier than many of us prob realized.