Plastic visors are much used for the protection of people in shops, bars and beauty salons (i.e. anywhere where close proximity between people is inevitable). They are now being commercially produced as well as people being guided to produce their own with online instructions. It now looks (after initial denials, when it was though that coughing was the main problem) that aerosol transmission of the Covid-19 virus in tiny droplets of water, produced when people exhale or speak, is a major means of transmission. Pretty obviously, this kind of spray is intensified when opera singers are giving it the full 'welly' so they have been studied (https://www.bbc.com/future/article/20200806-are-face-shields-effective-against-covid-19). Opera singers can produce clouds of droplets, extending more than a metre in front of their face and the visors do not prevent the aerosol escaping around the sides of a visor. Masks are more effective in this respect although it is difficult to sing opera in a mask. Some authorities in Switzerland and the USA do not now recommend the use of plastic visors alone but I guess they must help a little in relaxed, shop-based commerce.
No comments:
Post a Comment