Erin Bromage, an associate professor of biology at the University of Massachusetts Dartmouth, wrote a blog post titled The Risks – Know Them – Avoid Them.
« A single cough releases about 3,000 droplets [traveling at] 50 miles per hour. »
« A single sneeze releases about 30,000 droplets [traveling at] 200 miles per hour. »
« But even if that cough or sneeze was not directed at you, some infected droplets–the smallest of small–can hang in the air for a few minutes, filling every corner of a modest sized room with infectious viral particles. All you have to do is enter that room within a few minutes of the cough/sneeze and take a few breaths and you have potentially received enough virus to establish an infection. »
« It would take ~5 minutes of speaking face-to-face to receive the required dose. »
« Any environment that is enclosed, with poor air circulation and high density of people, spells trouble… Restaurants… Workplaces… Choir… Indoor sports… Birthday parties / funerals. »
« The reason to highlight these different outbreaks is to show you the commonality of outbreaks of COVID-19. All these infection events were indoors, with people closely-spaced, with lots of talking, singing, or yelling. The main sources for infection are home, workplace, public transport, social gatherings, and restaurants. This accounts for 90% of all transmission events. In contrast, infections while shopping appear to be responsible for a small percentage of traced infections. »
« I regularly hear people worrying about grocery stores, bike rides, inconsiderate runners who are not wearing masks…. are these places of concern? Well, not really… Importantly, of the countries performing contact tracing properly, only a single outbreak has been reported from an outdoor environment (less than 0.3% of traced infections). »
[ Corona virus, COVID-19 ]