Science & Technology

Experiments show that sunlight destroys the COVID virus eight times faster than scientists thought

Researchers encourage more in-depth investigation of the effectiveness of sunlight in inactivation SARS-CoV-2 Virus.

A year ago, scientists around the world were worried about the new coronavirus that caused the pandemic, SARS-CoV-2, from which we are just beginning to emerge. The world has insisted on all new developments, all sciences that may provide clues to manage life in the presence of this mysterious murderer.

Backed by a lot of science COVID-19 (new coronavirus infection) The concept of management has not changed to this day. Hand washing with soap and warm water destroys the lipid membrane of the virus. Social distance can reduce the spread of the virus, ideally keeping it away from the host until the virus is broken down. Other concepts, such as droplet contact being the primary mode of infection, when new evidence shows that the virus may remain suspended in the air for extended periods of time under certain conditions. It has been fixed.

Paolo Luzzatto-Fegiz

Paolo Luzzatto-Fegiz. Credit: UCSB

so letter In Journal of Infectious Diseases, University of California, Santa Barbara, Oregon State University, University of Manchester, and ETH Zurich are investigating the vulnerability of SARS-CoV-2 to sunlight, another well-known property. What are their conclusions? More than UV-B rays may be needed to explain the solar inactivation of SARS-CoV-2.

When the team compared the July 2020 data, the idea was born that additional mechanisms might be working. Survey Reported rapid sun inactivation of SARS-CoV-2 in the laboratory. theory Analysis of coronavirus inactivation by solar radiation published just a month ago.

“The theory is that UV-B RNA Paolo Luzzatto-Fegiz, professor of mechanical engineering and lead author at the University of California, Santa Barbara, said: However, judging from the discrepancy between the experimental results and the predictions of the theoretical model, the research team felt that UV-B inactivation of RNA “may not be all.”

According to the letter, the experiment showed a virus inactivation time of about 10-20 minutes-much faster than predicted by theory.

“Theory predicts that inactivation will be an order of magnitude slower,” said Luzzatto-Fegiz. In the experiments, the simulated saliva virus and the virus exposed to the UV-B lamp were inactivated more than eight times faster than theoretically predicted, but fully propagated before exposure to UV-B. Viruses cultured in medium were inactivated by 3 or more, many times faster than expected. According to the letter, SARS-CoV-2 must exceed the highest UV-B sensitivity of any virus currently known to fit theoretical mathematics into the data.

Alternatively, Luzzato-Fegiz et al. Inferred that another mechanism may be working apart from RNA inactivation by UV-B rays. For example, UV-A, another low-energy component of sunlight, may play a more active role than previously thought.

Yang In Chu

Yang Ying Zhu. Credit: UCSB

“People think UV-A isn’t very effective, but it may be interacting with some molecules in the medium,” he said. These reactive intermediate molecules can interact with the virus and accelerate inactivation. This is a well-known concept for people working in the fields of wastewater treatment and other environmental sciences.

“So scientists still don’t know what’s going on,” said Luzzat Fegiz. “Our analysis shows the need for additional experiments to individually test the effects of specific light wavelengths and medium composition.”

The results of such experiments may provide clues to new ways of controlling viruses with widely available and accessible UV-A and UV-B radiation. UV-C radiation has proven to be effective against SARS-CoV-2, but this wavelength does not reach the surface of the earth and must be manufactured. UV-C is currently used in air filtration and other environments, but its short wavelength and high energy make UV-C the most harmful form of UV light, limiting its practical use and other safety precautions. Concerns arise.

Yangying Zhu, co-author and professor of mechanical engineering at UCSB, added that it could be very beneficial if UV-A was found to be able to inactivate the virus. Number of times. UV-A could be much more widely used to enhance air filtration systems with relatively low risk to human health, especially in high-risk environments such as hospitals and public transport, but in each setting More details need to be considered. Temprano-Coleto.

See also: Paolo Luzzatto-Fegiz, Fernando Temprano-Coleto, François JPeaudecerf, Julien R Landel, Yangying Zhu, Julie A McMurry, “UVB radiation alone may not explain the sunlight inactivation of SARS-CoV-2”, 2021 February 5 Infectious disease journal.
DOI: 10.1093 / infdis / jiab070

The study in this paper was by François J of ETH Zurich. It was also done by Peaudecerf and Julien Landel of the University of Manchester.

Experiments show that sunlight destroys the COVID virus eight times faster than scientists thought Experiments show that sunlight destroys the COVID virus eight times faster than scientists thought

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