Nepal | August 07, 2020

Sunlight destroys coronavirus quickly, say US scientists

Agence France Presse
Share Now:

Washington, April 24

The new coronavirus is quickly destroyed by sunlight, according to new research announced by a senior US official day, though the study has not yet been made public and awaits external evaluation.

William Bryan, science and technology advisor to the Department of Homeland Security secretary, told reporters at the White House that government scientists had found ultraviolet rays had a potent impact on the pathogen, 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 favourable to the virus.”

But the paper itself has not yet been released for review, making it difficult for independent experts to comment on how robust its methodology was.

It has long been known that ultraviolet light has a sterilising effect, because the radiation damages the virus’s genetic material and their ability to replicate.

A key question, however, will be what the intensity and wavelength of the UV light used in the experiment was and whether this accurately mimics natural light conditions in summer.

“It would be good to know how the test was done, and how the results were measured,” Benjamin Neuman, chair of biological sciences at Texas A&M University-Texarkana, told AFP.

“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.”

Bryan shared a slide summarising major findings of the experiment that was carried out at the National Biodefence Analysis and Countermeasures Centre in Maryland.

It showed that the virus’s halflife — the time taken for it to reduce to half its amount — was 18 hours when the temperature was 70 to 75 degrees Fahrenheit (21 to 24 degrees Celsius) with 20 percent humidity on a non-porous surface.

This includes things like door handles and stainless steel.

But the half-life dropped to six hours when humidity rose to 80 percent — and to just two minutes when sunlight was added to the equation.

When the virus was aerosolised — meaning suspended in the air — the half-life was one hour when the temperature was 70 to 75 degrees with 20 percent humidity.

In the presence of sunlight, this dropped to just one and a half minutes.

Bryan concluded that summer-like conditions “will create an environment (where) transmission can be decreased.”

He added, though, that reduced spread did not mean the pathogen would be eliminated entirely and social distancing guidelines cannot be fully lifted.

A version of this article appears in e-paper on April 25, 2020, of The Himalayan Times.

Follow The Himalayan Times on Twitter and Facebook

Recommended Stories:

More from The Himalayan Times:

Gandaki Province CM Prithivi Subba Gurung

No statutory ground to seek PM’s resignation

Gandaki Province chief minister Prithvi Subba Gurung is NCP (NCP) Gandaki Province in-charge. A former secretary of then CPN-UML party, Gurung is the supporter of Prime Minister and NCP (NCP) co-chairperson KP Sharma Oli. As the intra-party feud has escalated lately, CM Gurung has been quite occupie Read More...

International Commission of Jurists calls for transparency and justice

KATHMANDU: International Commission of Jurists (ICJ), an international non-government organisation which works as advocate for justice and human rights, has called upon the Government of Nepal to undertake substantial reforms in order to ensure that the wide-ranging constitutional and political re Read More...

Industry's violation of COVID-19 safety protocol causes virus transmission in community

DHARAN: An industry has been held responsible for transmission of coronavirus at community level in Dharan Sub-metropolitan City of Sunsari district.  Negligence on the part of Priti Valve and Fittings Industries Pvt Ltd located in the Industrial Area of Dharan-8 has been  blamed for local Read More...

China, coronavirus

360 new coronavirus cases detected; nationwide tally hits 21,750

KATHMANDU: The Ministry of Health and Population has recorded 360 new cases of the coronavirus infection on Thursday, taking the nationwide count to 21,750. The new infections were confirmed after testing 6,622 specimens through PCR method across the nation in the last 24 hours. As many as 419,57 Read More...

Kathmandu valley sees highest daily-tally as 87 cases surface Thursday

KATHMANDU: As many as 87 Covid-19 cases were reported in Kathmandu valley in the last 24 hours, the highest single day tally recorded yet. Of the 87 cases, 76 cases were identified in Kathmandu alone while Lalitpur reported ten infections. Only one case was detected in Bhaktapur district on Thurs Read More...

Highest number of deaths registered in a single day in Nepal, five reported in 24 hrs

KATHMANDU: Five more fatalities related to the coronavirus infection have been reported today by the Ministry of Health and Population. This is the highest single-day deaths recorded in Nepal. A 45-year-old male from Rangeli Municipality-8 of Morang passed away on Wednesday, August 5. He had just Read More...

Man City sign Bournemouth defender Ake

LONDON: Manchester City have signed defender Nathan Ake from Bournemouth on a five-year deal, the Premier League club announced on Wednesday. Financial details of the transfer were not disclosed but British media reported City paid Bournemouth 40 million pounds ($52 million) to sign the 25-year-o Read More...