UV-emitting LED lights found to kill coronavirus

Finding suggests technology can be installed in air conditioning, vacuum, and water systems

Researchers from Tel Aviv University (TAU) have proven that the coronavirus can be killed efficiently, quickly, and cheaply using ultraviolet (UV) light-emitting diodes (UV-LEDs). They believe that the UV-LED technology will soon be available for private and commercial use.

This is the first study conducted on the disinfection efficiency of UV-LED irradiation at different wavelengths or frequencies on a virus from the coronaviruses’ family. The study was led by Professor Hadas Mamane, Head of the Environmental Engineering Program at TAU’s School of Mechanical Engineering, Iby and Aladar Fleischman Faculty of Engineering.

“The entire world is currently looking for effective solutions to disinfect the coronavirus,” said Professor Mamane. “The problem is that to disinfect a bus, train, sports hall, or plane by chemical spraying, you need physical workforce, and for the spraying to be effective, you have to give the chemical time to act on the surface. However, disinfection systems based on LED bulbs can be installed in the ventilation system, and air conditioner, such as sterilizing the air sucked in and then emitted into the room.

“We discovered that it is quite simple to kill the coronavirus using LED bulbs that radiate ultraviolet light,” she explained. “We killed the viruses using cheaper and more readily available LED bulbs, which consume little energy and do not contain mercury like regular bulbs. Our research has commercial and societal implications, given the possibility of using such LED bulbs in all areas of our lives, safely and quickly.”

The researchers tested the optimal wavelength for killing the coronavirus and found that a length of 285 nanometers (nm) was almost as efficient in disinfecting the virus as a wavelength of 265 nm, requiring less than half a minute to destroy more than 99.9% of the coronaviruses. This result is significant because the cost of 285 nm LED bulbs are much lower than that of 265 nm bulbs, and the former is also more readily available.

Eventually, as the science develops, the industry will make the necessary adjustments and install the bulbs in robotic systems or air conditioning, vacuum, and water systems, thereby efficiently disinfecting large surfaces and spaces. Professor Mamane believes that technology will be available for use shortly.

It is important to note that it is hazardous to use this method to disinfect surfaces inside homes. To be fully effective, a system must be designed not to be directly exposed to the light.

In the future, the researchers will test their unique combination of integrated damage mechanisms and more ideas they recently developed on combined efficient direct and indirect damage to bacteria and viruses on different surfaces, air, and water.

The study was conducted in collaboration with Professor Yoram Gerchman of Oranim College; Dr. Michal Mandelboim, Director of the National Center for Influenza and Respiratory Viruses at Sheba Medical Center at Tel HaShomer; and Nehemya Friedman from Tel Hashomer.