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There have been journalists questions about the risk of transmission of COVID-19 whilst outside, and the role of vitamin D.
Prof Keith Neal, Emeritus Professor in the Epidemiology of Infectious Diseases, University of Nottingham, said:
“Talking and coughing can produce droplets and aerosols. Droplets, which are larger than aerosols, carry more virus but fall rapidly to the ground under gravity. Aerosols are smaller and can drift further but also dry out quickly because they lose water content as they have a high surface area to volume unlike droplets. They are also rapidly dispersed with air movements and we rarely have no air movements outside.
“Sunlight includes ultraviolet radiation. This damages DNA and RNA. I have not seen any work on how quickly this affects COVID-19 but viruses left on surfaces outside will dry out and be damaged by UV light in sunlight.
“I totally agree that outside is very much safer than inside – you can be further apart and conditions outside are less conducive to virus survival than inside. I have been a strong advocate of allowing more outside leisure as it improves physical and mental health.
“There is some evidence that Vit D supplements reduce the risk of respiratory virus infections and there is good evidence that Vit D deficiency impairs the immune system. Vit D levels are low at the end of our winter and people staying inside will only prolong this. The only vitamin supplement recommended by PHE is Vit D in the winter.
“I intend to avail myself of the new recommendations and go fishing and play golf. The risk is miniscule and I think I am more likely to be killed by lightning (waving carbon fibres objects in the air attracts lightning strikes).
“I agree with SAGE – the use of outside spaces in a socially distant way is one of the lowest-risk forms of activity.”
All our previous output on this subject can be seen at this weblink: www.sciencemediacentre.org/covid-19/
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