Decades of research on UV light’s ability to fight germs sees new developments amid COVID-19.
Once the COVID-19 pandemic started, scientists and researchers went back to a germ-fighting solution: ultraviolet (UV) light. UV proved to be an effective weapon during the 2003 SARS outbreak. Back then, it was able to kill the virus within the environment before it infected people, but it isn’t just any UV light that works.
Most people are familiar with UVA and UVB rays, thus the extensive offerings of sunblock on the market. UVB rays have shorter wavelengths that affect the epidermis, the outer layer of skin, while UVA rays have longer wavelengths that can reach the middle layer, the dermis. While these rays, when safely absorbed, are needed for humans, they don’t do much to viruses. UVC rays, on the other hand, are blocked from coming down to Earth’s surface by the ozone layer but are what can “kill” viruses. Part of the reason they are so effective is that as all living things on Earth evolved, there was no exposure to UVC rays.
That is where science interjected by creating artificial UVC light. The lingering issue has been that, just like the unwanted viruses that are around, this type of radiation is unsafe for humans. Standard UVC products usually have a wavelength of 254 nm. Over time, exposure to these rays may lead to skin or eye damage. Thus, using this conventional light required doing so without humans present.
Continued research has focused on far-UVC, which is typically about 222 nm, making it safe enough for use with people present. In a study conducted at Columbia University Irving Medical Center, researchers determined that far-UVC can kill more than 99.9 percent of coronaviruses in airborne droplets.
Disinfecting Air, Rooms, and Supplies
From hospitals to restaurants to office spaces and other indoor settings, a growing number of upper-room germicidal UV (GUV) technologies have been rolling out. While GUV may not be anything new—it has long been recommended by the World Health Organization to combat tuberculosis—it has had a transformation thanks to strides in the use of far-UVC instead of traditional UVC.
A majority of the products available are fixtures installed in ceilings to continuously cleanse the air and minimize aerosolized coronavirus particles from spreading to other areas. AeroMed upped its GUV offerings with its Infinity series, which has a higher output of UV radiation. Designed for installation seven feet from the floor, these 14-pound units are 7.5 x 25.75 x 7.4 inches. Within a short time after it is turned on, the fixture begins to destroy any germ that it shines on.
The unit uses multiple parabolic reflectors to direct the UV energy out of the fixture, which enables all of the light emitted from the source to be reflected in one direction.
Safeology is another innovator in the UVC sector. It offers a line of towers, air purifiers and upper-room light fixtures. Its light fixtures, which use an optimized UVC beam to clean circulating air, proved to deactivate 99.9 percent of airborne viruses.
The company’s UVC Mobile Air Purifier 1800 works round-the-clock to provide pathogen protection. Along with UVC light, which takes care of airborne pathogens, the fixture has a built-in activated carbon filter and a HEPA filter that remove 99.97 percent of allergens, mold, bacteria and other irritants from the air. Its UVC Tower Elite is a movable, lightweight device with 360-degree UVC emittance.
Along with cleaning surfaces and the air, other devices are geared more toward frontline workers and their protective gear. In response to COVID-19, Cleanbox Technology developed a point-of-use mask decontamination solution, CleanDefense. The lightweight device is designed for N-95, cloth, and other layered masks. It can clean four masks at a time on a two-minute cycle, which equates to around 100 masks an hour.
Its existing CX Series also focuses on products worn on the head or face, which are high-risk contagion transfer points. The company has three models that are designed to disinfect mixed materials or irregularly shaped gear, including headsets, HMD controllers and earphones.
The Future of UVC Protection
In an era full of technological advances, it is no surprise that robots have played a role in the fight against COVID-19 and will continue to do so. Cleaning robots are on the rise, especially ones equipped with UVC. The upcoming year will welcome a host of new disinfecting robots.
LG is rolling out the CLOi robot. This autonomous cleaning machine can move around furniture while emitting UVC to disinfect the touchable surfaces in a room in about 15 to 30 minutes. Its battery allows it to clean multiple areas on one charge. Designed for easy operation, it requires no special training to use and can be remotely monitored via a mobile app.
Unipin’s ultraviolet disinfection robot touts a 99.99 percent disinfection rate and is capable of cleaning 1,000 square meters in 100 minutes. It uses LiDAR to navigate and has wireless connectivity. Along with UVC output, the robot also incorporates photocatalyst and negative ion technologies and has a HEPA filter and a honeycomb ceramic filter element to clean the air.
With more public areas looking to go the way of hospitals, anti-contamination robots are an ideal solution. Ubetech is launching a robot geared toward schools and small businesses. Its offerings include the Adibot-S, which must be manually moved to new locations, and the autonomous Adibot-A.
While robots may provide a solution for many indoor spaces, research continues looking at broader ways to harness UVC light. Columbia University’s Center for Radiological Research has continued to focus on GUVs, but in an easier and more affordable way, as well as a potential solution for large public spaces, such as airports. The research team has been developing UVC lamps that could eradicate airborne viruses and bacteria. The lamps are different in that they can be used in easily retrofitted existing light fixtures.
Other researchers are focusing on materials that could harness the power of UV radiation to disinfect surfaces. At the University of New Mexico, a research team led by David Whitten, Center for Biomedical Engineering, published a paper on research focused on combining near-UV and visible light with a blend of certain polymers and oligomers to kill the coronavirus.
Popular disinfectants, such as bleach and alcohol, effectively kill the virus but are corrosive and volatile in nature. Along with easily washing away and leaving potentially toxic residue behind, they also don’t provide long-term sterilization of surfaces.
The researchers discovered that when their polymer and oligomer materials are activated by near-UV and visible light, it creates a rapid-acting coating that immediately reduces virus concentration by five orders of magnitude. According to Whitten, the light activates a vital “docking” process for placing the oligomer or polymer at the surface of the virus particle. It allows the absorption of light, which generates the reactive oxygen intermediate at the surface of the virus particle that deactivates the virus. The researchers believe this science has potential uses across sectors. It could be incorporated into wipes, sprays, paint and other surfaces for long-lasting protection.
While the world awaits receiving the vaccine for the current pandemic, history has shown that another devastating virus is likely lurking and waiting to create a new crisis. The increased use of UVC light may not be able to stop another pandemic from happening, but it is proving to be a highly efficient method of reducing its spread and keeping public areas disinfected.
