New study shows summer sun can kill coronavirus in 30 minutes, but other experts are sceptical

London - Virologists found that powerful UV light could destroy 90% of Covid-19 virus load coughed or sneezed onto a surface in just half an hour.

As the US and the UK gear up for this year's summer amid the pandemic, it is possible that coronavirus cases see a spike in transmission again as millions of people will be outdoors.
But putting the fears of transmission to rest, virologists found that powerful ultraviolet (UV) light could destroy 90 per cent of Covid-19 virus load coughed or sneezed onto a surface in just half an hour.
While separate studies have claimed that sunlight is capable of completely wiping out parts of the virus when it is exposed to UV sun rays for just six minutes, reported Daily Mail. 
Stressing that people are safer outdoors, research by retired virologists from the US army and US food and drug administration showed that sunlight kills the virus, and that being indoors during lockdown may have been harmful for people. Moreover, some scientists also believe that vitamin D which is made in the body when exposed to sunlight, boosts the immune system and can help fight off viruses.
According to a report in Independent.ie, a study by the US National Biodefense Analysis and Countermeasures Centre found that coronavirus decays by 90 per cent in just six minutes in the summer sun while it takes 19 minutes of winter sunlight to do the same.
In a similar study by Harvard University, it was found that at 6 degrees Celsius in dry weather, flu on a surface ­survived for over 23 hours, but in 32 degrees Celsius the virus died within an hour.
But some researchers are sceptical about the summer sunlight playing a role in curbing the spread of the virus. Dr Clarke, a cellular microbiologist at the University of Reading, said, "There are summer colds and there's a coronavirus that causes summer colds, so it's not a given. We've heard a lot of people suggest that warmth and sunlight would rid us of the virus but if that were the case we wouldn't have problems in Brazil or Florida or Singapore."
Dr Clarke pointed out that food factories seemed to have been the centre of outbreaks more than other factories where people might be close together. Dr Michael Head, a global health researcher at the University of Southampton, said, "Whilst refrigeration may be a contributory factor to the spread of the virus, the key factors are likely to be the number of people close together in indoor conditions."