Bright sun reduces transmission of COVID-19: ultraviolet radiation kills virus

Ultraviolet light is able to reduce the infection rate of COVID-19

The scientists found that UV radiation reduces the level of infectious transmission of the COVID-19. The research is being carried out by a group of specialists from the University of California. They said they had an evidence of the sensitivity of the coronavirus infection to ultraviolet rays. The virus can change from one season to another, but other seasonal factors, such as high or low temperatures, humidity, precipitation, have not been considered.

A researcher Kyle Meng noted that related species such as the 2003 SARS and 2012 MERS were both temperature and humidity sensitive. They were also sensitive to UV radiation. By highlighting this fact, the scientists are studying the relationship between UV radiation and the spread of the new coronavirus infection.


In their work, they analyze different situations of the emergence of the virus and its response to the environment. To account for economic, social conditions, and not just climatic ones, the researchers conducted a longitudinal study of the issue, comparing, in fact, populations with themselves over time.

Instead of comparing Brazil and the United States, the scientists compared groups of communities in Brazil with each other, and the same thing separately in the United States. In doing so, they answered the questions about how daily fluctuations in environmental conditions affect the spread of the disease.

For that, completely disparate statistical data were used to create a global set of information, consisting of more than three thousand spatial units. The scientists then used the meteorological data to correlate local environmental conditions with the daily count of the COVID-19 cases.


They applied a basic set of statistical methods and analyzed four main variables: UV radiation, temperature, humidity and precipitation, and found out how they correlate with the daily increase in cases of illness.

Thus, the scientists found the evidence that exposure to ultraviolet radiation in a certain area significantly affects the transmission of the COVID-19. For example, UV radiation from May to June in Los Angeles significantly reduced the rate of the coronavirus disease in this area.

Reference: “Global evidence for ultraviolet radiation decreasing COVID-19 growth rates” by Tamma Carleton, Jules Cornetet, Peter Huybers, Kyle C. Meng and Jonathan Proctor, 15 December 2020, Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.2012370118