Can you stop COVID-19 with sunlight?

Sunlight may play a role in reducing the survival rate of the SARS-CoV-2 virus on surfaces and in the air, but it cannot completely stop COVID-19.

UV radiation, especially UV-C, can inactivate viruses by damaging their genetic material. This process is called photodimerization and leads to the destruction of the viral RNA or DNA, making the virus no longer infectious.

Studies have shown that UV-C radiation is effective in inactivating SARS-CoV-2 on various surfaces and in aerosols. However, UV-C radiation is harmful to human skin and eyes and therefore cannot be used directly for disinfection of people or public spaces without protective measures.

The natural sunlight that reaches the earth consists mainly of UV-A and UV-B radiation, which are less effective in inactivating viruses than UV-C. Although UV-B can provide some degree of viral inactivation, it is less powerful than UV-C and works more slowly.

While sunlight and UV radiation can help inactivate SARS-CoV-2 on surfaces and in the air, it is not enough to completely stop COVID-19. It remains important to follow other preventive measures, such as wearing masks, social distancing, and washing hands.

Source: https://www.nature.com/articles/s41598-020-79600-8

Author: Prof. Dr. Dirk Devroey - Latest update: 2023-12-09 - Copyright: Clinifacts 2025