Every Monday, we’ll answer your questions on Covid-19 and health in a feature published online. You can submit a question here.
HuffPost UK reader Pete asked: “Can you catch Covid in a busy park?
As the weather warms up, parks are going to get busier again – especially since Boris Johnson’s roadmap states people will be able to sit with one other person from March 8 – and five other people from March 29.
So as we, once again, have picnics with our pals on the grass, are we putting ourselves at risk? “We know this virus transmits during close contact with people,” says Dr Julian Tang, clinical virologist at the University of Leicester.
If a park is very crowded, with less than two metre spacing between groups, where no masks are worn, “the virus can still potentially transmit”, he says. “If most people have been vaccinated, and there is a strong breeze and strong sunlight, this risk will be less.”
Paul Hunter, professor in Medicine, at the Norwich School of Medicine, University of East Anglia, adds that the evidence is that transmission of Covid outside is much lower – about 19-fold less – than transmission indoors.
“There was also no obvious outbreak associated with the very crowded beaches that we saw last spring and summer,” he adds. “That does not mean that such transmission is impossible but it will be unlikely to play an important role in the spread of the epidemic.”
The highest risk of transmission is during face-to-face conversation between unmasked people, less than one metre apart, if there is less wind and less sunlight, says Dr Tang. In these conditions, the virus can pass quickly between individuals at this distance through the air.
“Standing close to someone not from your household or support bubble face to face whilst talking still should be avoided,” says Prof Hunter. “But sitting near other people, especially if more than two metres apart whilst not socialising with them, would be a very low risk.”
Prof Keith Neal, professor of the Epidemiology of Infectious Diseases, University of Nottingham, says the benefits of exercise and vitamin D are much greater than the risks of not going outside at all. When lying down especially, the sunbathing droplets you breathe out will “go virtually nowhere”, he says.
Closing parks isn’t an option for local and national government, adds Prof Neal, as “forcing people into places where distancing is less practical”.
So, while going to a busy park may not be super risky, you should still abide by distancing measures. Professor Jonathan Reid, director of Bristol Aerosol Research Centre, says there have been “very few recognised cases” of transmission outside and only when people were “not observing the guidance on physical distancing”.
“It is also important people still recognise the risks of any indoor spaces they might use when visiting an outdoor venue, such as toilets, changing rooms and cafes,” he adds.
If a park looks, or becomes, too crowded, you can go somewhere else. “The important thing to remember is that no one who gets vaccinated at the moment is routinely tested for an antibody response, so you don’t actually know if you might be one of the few that has not responded to the vaccine,” sats Dr Tang. “This non-response rate is typically around 5-10% across all vaccines.
“Despite the rapid vaccine rollout, people still need to be aware of potential transmission risks – particularly with the circulation of multiple potentially more transmissible, partial vaccine escape virus variants – which includes crowded outdoor situations also.”
Experts are still learning about Covid-19. The information in this story is what was known or available at the time of publication, but guidance could change as scientists discover more about the virus. To keep up to date with health advice and cases in your area, visit gov.uk/coronavirus and nhs.uk.