Beneficial Effects of UVC Radiation on COVID-19

By Emma Ferraro

March 2, 2022

UPDATED 12:00 AM EST

[Photo credit: Ushio America, Inc.]

Public health officials across the world have not failed to conclude that the spread of COVID-19 can be influenced by a vast number of factors: mask wearing, social distancing, hand washing, etc. However, there are other factors that may exhibit preventative effects―one of which is UVC radiation.

A study by the Proceedings of the National Academy of Sciences of the United States of America (PNAS) conducted a study and were able to declare that an increased rate of UVC (100 - 280 nanometer wavelengths, shorter than UVA and UVB) radiation works to lower the daily growth rate of COVID-19 cases over the course of two and a half weeks. This means that changes of season and temperatures throughout the year can “alter the global spatial pattern of COVID-19 and inform local public health responses” (PNAS).

In order to put this piece of research into effect, the FDA is encouraging special ultraviolet-C (UVC) lamps in order to disinfect surfaces subject to being befouled by COVID-19. They claim that the UVC radiation has the ability to disinfect a variety of surfaces, whether they are air, water, or nonporous. This includes the ability to reduce bacterial spread, coining UVC lamps the name “germicidal lamps.” They’ve been used in the past to reduce the spread of tuberculosis, a potentially serious infectious airborne disease that affects the lungs. These lamps are being investigated to see if they can have the same preventative effect on COVID-19, a disease with the same mode of transmission.

Air ducts commonly contain releasers of UVC radiation in order to disinfect the air. Since UVC radiation often is dangerous when reflected directly onto human skin, as it is known to be a major contributor to skin irritations and cancers. It can also be dangerous to the eyes, potentially causing photokeratitis, a short term eye irritation caused by UVC radiation with symptoms including redness, blurriness, tearing, swelling, light sensitivity, and headaches. When implemented in air ducts, the risk of being exposed to UVC radiation in both the skin and eyes significantly decreases.

There are many different UVC lamps that can be put into use to limit the growth rate of the COVID-19 virus, all varying in the lengths of the emitted waves. For example, low-pressure mercury lamps (pictured above), the most common UVC radiation-producing lamp, offer a specific wavelength emission at mainly 254 nm. On the other hand, pulsed xenon lamps possess the ability to produce a broad spectrum of light, not limited to just UVC, and are commonly used in hospital settings where no humans are present.

The question as to whether or not UVC lamps are both safe and effective is still one being studied comprehensively by scientists and public health officials globally.

References

"Global Evidence for Ultraviolet Radiation Decreasing COVID-19 Growth Rates." PNAS, 5 Jan. 2021, www.pnas.org/content/118/1/e2012370118.

"Ultraviolet (UV) Radiation." U.S. Food and Drug Administration, 19 Aug. 2020, www.fda.gov/radiation-emitting-products/tanning/ultraviolet-uv-radiation.

"UV Lights and Lamps: Ultraviolet-C Radiation, Disinfection, and Corona." U.S. Food and Drug Administration, 1 Feb. 2021, www.fda.gov/medical-devices/coronavirus-covid-19-and-medical-devices/uv-lights-and-lamps-ultraviolet-c-radiation-disinfection-and-coronavirus.