https://www.theguardian.com/commentisfree/2020/jun/18/anti-racism-protests-coronavirus-rise-covid-19-cases
The evidence is becoming clear
that wearing a mask can substantially lower the risk of spread and
severity of illness. We are seeing more and more masks worn by
protesters. A second feature of gatherings that affects the spread of
the virus is whether they happen outdoors or indoors. Here, too, research suggests that outdoor activities are much safer than indoor ones.
Finally, although this is more preliminary, evidence suggests that if you’re going to be in a crowd, a mobile one is better than a stationary one. None of these three aspects will protect you from infection definitively – but together they offer a modest level of risk reduction. And compared with the risk of catching Covid-19 that is present in many jobs or other activities, such as working in meat-packing plants, outdoor protests are likely to be much safer– especially if we carry out testing, which can quickly reveal if the virus is spreading among protesters, as Massachusetts has done recently.
Finally, although this is more preliminary, evidence suggests that if you’re going to be in a crowd, a mobile one is better than a stationary one. None of these three aspects will protect you from infection definitively – but together they offer a modest level of risk reduction. And compared with the risk of catching Covid-19 that is present in many jobs or other activities, such as working in meat-packing plants, outdoor protests are likely to be much safer– especially if we carry out testing, which can quickly reveal if the virus is spreading among protesters, as Massachusetts has done recently.