Scientists at the University of California, Santa Barbara have proven that sunlight is effective against the spread of the SARS-CoV-2 coronavirus. This is reported in an article published in the journal Proceedings of the National Academy of Sciences.
Researchers analyzed how many cases of infection are observed in the same countries, but with changing environmental conditions, including temperature, humidity, rainfall and ultraviolet radiation. This approach avoids the influence of third-party factors, for example, welfare and the level of development of social institutions, which cannot be ignored when comparing different countries.
The time delay between the change in climatic conditions and the level of infection with coronavirus was also taken into account, since the incubation period between infection and the appearance of the first symptoms reaches 4-7 days on average; besides, some time is spent on testing.
An increase in the amount of ultraviolet radiation coming from solar radiation from May to June, typical for Los Angeles, turned out to reduce the number of new cases by one percent. In northern temperate regions, the model predicts that the rate of new COVID-19 cases decreases by 7.4 percent from January to June due to increased insolation.
However, scientists note that adhering to social distancing is more beneficial for significantly reducing the incidence.