JAKARTA, SENAYANPOST.com – A team of scientists has recently seen that the coronavirus may be more susceptible to ultraviolet radiation than had been previously thought.
UC Santa Barbara mechanical engineer Paolo Luzzatto-Fegiz and colleagues saw the inactivation of the coronavirus eight times faster in experiments than would be expected in theory.
“The theory assumes that inactivation works by making UVB on viral RNA, and then destroying it,” explained Luzzatto-Fegiz. Kompas.com.
UV light, or portions of the ultraviolet spectrum, are readily absorbed by certain nucleic acid bases in DNA and RNA, which can cause them to bind in ways that are difficult to repair. But not all UV rays are the same.
The longer UV waves, called UVA, don’t have enough energy to cause problems.
Medium-range UVB waves in sunlight are responsible for killing microbes, but put the body’s cells at risk of sun damage.
Meanwhile, shortwave UVC radiation has been shown to be effective against viruses such as SARS-CoV-2, even though the radiation is still safely stored in human fluids.
But this type of UV doesn’t usually come into contact with the earth’s surface, thanks to the ozone layer.
“UVC is great for hospitals,” said co-author and Oregon State University toxicologist Julie McMurry.
“But in other environments – for example, kitchens or subways – UVC will interact with particulates and produce harmful ozone.”
Launching Science Alert, in July 2020, an important study found that simulated sunlight quickly deactivates SARS-CoV-2 on the surface.
According to their estimates, 90 percent of the SARS-CoV-2 virus was deactivated every 10-20 minutes in simulated saliva when exposed to simulated sunlight representing a hot summer day at sea level.
The following month, another study produced a theoretical model describing the inactivation of SARS-CoV-2 by sunlight. Luzzatto-Feigiz and team compared the results of the two.
The study found the SARS-CoV-2 virus was three times more sensitive to UV rays in the sun than influenza A, with 90 percent of coronavirus particles deactivated within just half an hour of exposure to midday sunshine in summer.
In comparison, in winter, light infectious particles can remain intact for days.
Environmental calculations made by a separate research team concluded the viral RNA molecule was being damaged photochemically, directly by light rays.
This is more strongly achieved with shorter wavelengths of light, such as UVC and UVB.
Because UVC does not reach the Earth’s surface, they based their calculations of environmental light exposure on the UVB medium-wave portion of the UV spectrum.
“The experimentally observed inactivation in saliva simulations was more than eight times faster than would be expected from the theory,” wrote Luzzatto-Feigiz and colleagues.
“But scientists don’t know what’s going on yet,” said Luzzatto-Fegiz.
The researchers suspect it is possible that instead of directly affecting RNA, long-wave UVA might interact with the molecule in the test medium (simulated saliva) by speeding up viral inactivation.
The same is seen in wastewater treatment – where UVA reacts with other substances to create molecules that destroy viruses. If UVA could be harnessed to combat SARS-CoV-2, a special low-cost and energy-efficient wavelength light source might be useful in enhancing air filtration systems with relatively low risk to human health.
“Our analysis suggests the need for additional experiments to separately test the effects of specific wavelengths of light and the composition of the medium,” Luzzatto-Fegiz concluded.
However, with the ability of the corona virus to float in the air for a long time, the safest way to avoid it is to maintain social distancing and wear a mask.
But it is certainly good news, that sunshine might help us during the summer. This analysis has been published in The Journal of Infectious Diseases.