The United States government has revealed that the novel coronavirus can quickly be killed under sunlight and higher temperatures.
The was made known on Thursday at a press conference after a research carried out by the Department of Homeland Security.
According to the study, it took 18 hours for the deadly coronavirus particles to decrease by half in a dark, low-humidity environment where the temperature was between around 21 C and 24 C.
The research which was conducted at a biocontainment laboratory in Maryland on nonporous surfaces, such as door handles and stainless steel, also revealed that radiation given off by ultraviolet light damages the virus’ genetic material and hampers its ability to replicate, as the virus dropped to six hours in a high-humidity environment and to two minutes when also exposed to sunlight.
Under increased temperature and high humidity without sunlight, the study found that the half-life of the deadly virus was one hour.
Results of the research were presented to reporters at the White House last night by William Bryan, a Department of Homeland Security science and technology advisor.
Bryson revealed that increased temperature and humidity were also detrimental to the virus, offering hope that its spread may ease over the summer.
‘Our most striking observation to date is the powerful effect that solar light appears to have on killing the virus, both surfaces and in the air,’ he said.
‘We’ve seen a similar effect with both temperature and humidity as well, where increasing the temperature and humidity or both is generally less favorable to the virus.’
Mr Bryan shared a slide summarizing major findings of the experiment that was carried out at the National Biodefense Analysis and Countermeasures Center in Maryland.
It showed that the virus’s half-life – the time taken for it to reduce to half its amount -was 18 hours when the temperature was 70-75F (21-24C).
That was based on a 20 per cent humidity on a non-porous surface, which includes things like door handles and stainless steel.
But the half-life dropped to six hours when humidity rose to 80 per cent – and to just two minutes when sunlight was added to the equation.
When the virus was aerosolized – suspended in the air – the half-life was one hour when the temperature was 70-75F with 20 per cent humidity.
In the presence of sunlight, this dropped to just one and a half minutes, according to the slides.
The paper itself was not immediately released for review, making it difficult for other experts to comment on how robust its methodology was.
A key question will be what the intensity and wavelength of the UV light used in the experiment was.
For instance, it may have been under a setting that did not accurately mimic natural light conditions in summer.
Dr Benjamin Neuman, chair of biological sciences, Texas A&M University-Texarkana, said: ‘It would be good to know how the test was done.
‘Not that it would be done badly, just that there are several different ways to count viruses, depending on what aspect you are interested in studying.’