Context: Scientists are studying the use of ultraviolet germicidal radiation (UVGI) to detect the virus in schools, restaurants and other public places. 

More on the news: 

  • Through this method, ultraviolet (UV) lights would be able to disinfect contaminated public spaces to stop the transmission of the virus.
  • Research published in the Princeton Public Health Review explains that UV light kills cells also.


  • As countries begin relaxing restrictions, questions are being asked on how post-lockdown scenarios will shape-up and what the new normal will be. 
  • Several countries are mandating behavioural changes, like social distancing and wearing masks, while others have considered issuing immunity passports or risk-free certificates.

About ultraviolet radiation:

  • UV light from the sun has shorter wavelengths than visible light and, therefore it is not visible to the naked eye. 
  • The full spectrum of UV radiation is sourced from the sun and can be subdivided into UV-A, UV-B and UV-C rays. 
  • In this spectrum, UV-C rays are the most harmful and are completely absorbed by the Earth’s atmosphere. 
  • Further, while both UV-A and UV-B rays are harmful, exposure to UV-B rays can cause DNA and cellular damage in living organisms.

How does UVGI work?

  • UVGI uses these destructive properties of UV light to target pathogens. 
  • It is thus considered effective in disinfecting the air and helps in preventing certain infectious diseases from spreading.
  • To elaborate, UVGI replicates UV wavelengths that disinfects contaminated spaces, air and water. 

How feasible is UVGI?

  • Earlier, the CDC issued guidelines for use of UVGI, intended to eliminate the spread of infection to healthcare workers from patients or others with unsuspected or undiagnosed infection of Tuberculosis.
  • According to a paper published in Public Health Reports, UVGI is most effective in preventing infections that are chiefly spread through smaller droplets and not by direct contact or larger respiratory droplets.
  • While using UVGI, it is important to consider factors such as 
    • the sensitivity of microorganisms to UVGI, 
    • the dose of UVGI required to kill them, 
    • humidity and weather conditions. 
  • Further, UVGI relies on air circulation in a room, which means the circulation of air needs to be such that air from below the room, where the pathogen is generated reaches the upper-portions of the room, where the UVGI can trap the pathogen.
  • Concerns: Increased exposure to UV radiations can cause cells to become carcinogenic, thereby increasing the risk of getting cancer. In fact, it is the increased direct exposure to UV rays from the sun that most commonly causes skin cancers.

Hence, using UVGI on a mass-scale, in public spaces such as schools, universities, restaurants and cinema halls may not be the most cost-effective way to approach disease prevention.

Source: https://indianexpress.com/article/explained/explained-can-ultraviolet-light-help-detect-kill-the-coronavirus-6402346/