Sunlight kills the coronavirus faster than expected. What is behind this?
The coronavirus has been with us for over a year. However, to this day we do not know how sunlight affects it, how much it can help slow it down.
The coronavirus has enemies. They are white blood cells from the group of lymphocytes that destroy infected cells, vaccines or the sun, and therefore sunlight.
Experts from the University of California at Santa Barbara, led by Professor Paolo Luzzatto-Fegiz, point to the role of sunlight. They published an article on the university’s website stating that it is necessary to test the ability of solar radiation (more precisely, the sun’s ultraviolet radiation) to destroy coronavirus particles.
The researcher had to find out that there is a theoretical difference between theoretical and experimental results – the virus was destroyed in experiments with sunlight several times faster than predicted by the theoretical model.
Ten minutes is enough
In June 2020, a theoretical study concluded that 90 percent of coronavirus particles should be inactivated after half an hour of summer sunlight around noon.
A month later, researchers in the laboratory tested the effects of ultraviolet radiation, which corresponds to summer sunlight, on SARS-CoV-2 in a solution resembling human saliva. In this case, the virus was destroyed in just 10-20 minutes.
Luzzatto-Fegiz emphasizes that it is unclear what the difference is between the studies. Nobody has dealt with this yet.
“Knowing how the sun can help us fight the coronavirus can be helpful,” the researcher wrote on the University of California website.
Who explains the difference?
The theoretical study is based on a model in which viruses destroy UV radiation. This ultraviolet radiation with a wavelength of 280 to 315 nanometers – nanometer (nm) is a billionth of a meter (10−9).
The UVB band has a detrimental effect on living organisms. Its energy is able to break down proteins and other organic compounds.
UV radiation also damages RNA, which carries hereditary information about viruses. “The theory is that inactivation of the coronavirus should be much slower. The difference between experimental and theoretical results suggests that the decomposition of RNA by ultraviolet radiation may not be the whole story,” wrote Professor Luzzatto-Fegiz.
His colleague Yang Jing Chu suggests that the less energetic component of radiation with a wavelength of 315 to 400 nanometers contributes to the destruction of viruses. It is called UVA and makes up 99 percent of the sun’s ultraviolet radiation that reaches the earth’s surface. According to Chu, it can react with some molecules, which in turn can react with virus particles and damage them.
“This difference indicates the need for further experiments to test the effect of certain wavelengths of light falling from the Sun on the Earth,” says Professor Luzzatto-Fegiz.