New discovery: Sunlight can neutralize corona virus in 6-14 minutes

In addition to detecting that the sun can neutralize the corona virus in 6-14 minutes, the scientists found that the spread of the virus significantly decreased in the environment with direct sunlight.

The results of a new study published in The Journal of Infectious Diseases show that the sun can neutralize the SARS-CoV-2 virus that causes acute respiratory infections. Covid-19.

According to the Newsweek in the US on May 22, to find out how the SARS-CoV-2 virus can survive under outdoor conditions, the scientists conducted an experiment with a device. Simulate natural laboratory sunlight that has been adjusted to the right temperature and humidity. 

People wear masks when they go out in Chon Buri province, east of Bangkok, Thailand - (Image: REUTERS)

The virus is grown in a laboratory environment and in an artificial liquid that resembles human saliva. The virus samples were then exposed to stainless steel plates. 

The virus-infected steel plates are hung in a laboratory and exposed to sunlight simulating 2-18 minutes. Some other infected steel plates were left in the dark for about 60 minutes.

Results showed that the ultraviolet B rays neutralized the SARS-CoV-2 virus. In the midday sunlight simulation of the longest day of the year at 40 degrees north latitude, 90% of the viruses in saliva were disabled after only 6.8 minutes. 

Meanwhile, sunlight simulating winter solstice at the same latitude also killed the virus in saliva after about 14.3 minutes. In contrast, the viruses exposed on steel plates placed in the darkness hardly changed.

According to the research, SARS-CoV-2 virus is disabled twice as quickly when in saliva than in culture, but scientists have not found a reason to explain this. 

In addition, the spread of SARS-CoV-2 virus can be significantly reduced in the environment outside of direct sunlight. The team concluded that natural sunlight acts as a disinfectant on contaminated non-porous surfaces.

According to Professor Ron Eccles of Cardiff University in the UK, the results of the study are interesting and help scientists understand more about the effect of outdoor ultraviolet rays in destroying viruses. 

Scientists have known for years that ultraviolet rays can neutralize many viruses and bacteria, so it has been widely used to disinfect operating theaters in hospitals.