Sunlight appears to inactivate the device coronavirus which causes COVID-19, according to a study.
Scientists have found an imitation of sunlight “quickly inactivated” SARS-CoV-2 of stainless steel coupons in the laboratory. The results were published in The Journal of Infectious Diseases.
Past studies have shown that SARS-CoV-2 can stay in the right conditions on non-porous internal surfaces for days, the authors explain in their document. A widely peer – reviewed study published in New England Journal of Medicine showed that the embryo can live up to three days on plastic and steel, compared to 24 hours on cardboard, four hours on copper and up to three hours as an aerosol.
However, in updated guidelines published earlier this month, which made headlines over the past day, the US Centers for Disease Control and Prevention says the virus is not thought to spread easily by touching surfaces or objects.
To find out if SARS-CoV-2 can survive in conditions similar to the outdoors, the team uses a device that simulates natural sunlight, including ultraviolet rays. They also controlled the temperature and humidity in a laboratory chamber. The virus is grown in both laboratory cultures and in a liquid resembling human saliva. The samples were then dried on stainless steel coupons.
Contaminated coupons were taped and attached to the chamber wall and exposed to light for various periods of time ranging from 2 to 1
Ultraviolet B (UVB) were detected rays that rapidly inactivate SARS-CoV-2, according to the team. In conditions resembling midday sunlight on the longest day of the year at 40 degrees north latitude, 90 percent of the virus is inactivated every 6.8 minutes in saliva.
Sunlight, representing the winter solstice at the same latitude, inactivates the virus every 14.3 minutes in saliva. SARS-CoV-2 is inactivated at speeds twice as high in saliva as in culture media for reasons that were not immediately clear. The virus at the parties, kept in the dark, has barely changed in the meantime.
The results show that the virus’s ability to spread can be “significantly reduced” in outdoor conditions when exposed to direct sunlight compared to indoor conditions, the authors wrote. “In addition, these data provide evidence that natural sunlight can be effective as a disinfectant for contaminated non-porous materials,” they said.
However, the team stressed that the results may differ in the actual scenarios. They say: “While significant levels of virus inactivation were observed within minutes in all simulated sunlight levels studied, it should be noted that the duration of each day outdoors UVB levels exceed those used in the present study, depends not only on the time of year but also on local weather conditions, especially the cloud cover.
“In this way, there may be significant day-to-day variability in the sustainability of SARS-CoV-2 on surfaces in the external environment. “
The team noted that they are using one size droplet of the virus and future studies could look at how this could affect deactivation. And although they tried to simulate saliva, it could differ from that of an infected person and distort the results.
To reveal the full risk of exposure to SARS-CoVMore research is needed in the open, looking at variables such as the viral load on different surfaces, how easily the virus passes from objects and the amount of virus needed to cause infection, they said.
Professor Dr. Ron Eccles of Cardiff University of Biological Sciences, an expert on the nose and upper respiratory tract, spoke. Newsweek: “The study is interesting and adds new knowledge to our understanding of how UV light works on viruses outside the door.
“It has been known for many years that UV light inactivates viruses and bacteria, and UV light is used to sterilize hospital operating rooms when not in use. The new knowledge is that high-intensity UV light observed on a sunny beach inactivates viruses. like SARS COV-2 and this is important because it means that we are safer outside than in all indoor public spaces.
“Stay home” should be replaced with “stay outdoors in the sun, but use sunscreen and keep your distance from others, as viruses can still be spread by coughing and sneezing.” “
This week, five months in COVID-19 pandemics, the total number of confirmed cases reached 5 million, according to Johns Hopkins University, A total of 333,001 people died COVID-19, and more than 1.9 million are known to have recovered. The United States is the country with the most famous COVID-19 cases, as the chart from Statistician broadcasts.
This article has been updated with commentary by Professor Ronald Eccles.