Can UV Light Kill the Coronavirus? Here's What to Know About UV-C Light
UV-C light, a specific range of UV light that is germicidal, is helping to sanitize masks at hospitals.
The shortage of sterile masks and other personal protective equipment (PPE) for healthcare workers has forced hospitals and university researchers to think outside the box—and look into their backyards. In Bethlehem, Pennsylvania, for example, St. Luke's Hospital and Lehigh University researchers collaborated to invent a UV light device nicknamed the "bug zapper" to sterilize their coveted N95 masks. The sterilization tool is capable of deactivating the coronaviruses using UV-C light, a specific range of ultraviolet light that is germicidal.
Christopher Roscher, MD, St. Luke's University Health Network anesthesiologist, had been doing private research to find ways to decontaminate masks for reuse. "Peer-reviewed literature suggested that, in a pandemic, UV-C light could be an acceptable strategy to sterilize masks," he said in a press release from St. Luke's.
Roscher reached out to Nelson Tansu, PhD, director of Lehigh University's Center for Photonics and Nanoelectronics, to explore the idea. Within two weeks, Lehigh students and staff designed, fabricated, installed, and tested the device, which resembles a "huge backyard mosquito zapper."
The team—students, PhDs, and MDs—originally developed a design cylindrical in shape to ensure even exposure of the light on all surfaces, but that would have required healthcare workers to individually rotate 200 masks 180 degrees halfway through the process. Then Tansu's adolescent son Axel gave him an idea: "What about an octagon?'
The team redesigned the structure with octagonal sides that allow staff to rotate 24 masks at a time, using only eight touch points versus 200. "It is incredible that this project moved at such a rapid speed," Tansu said in a statement. "I have been in the engineering and innovations world for 20-plus years and this is definitely record speed.''
The innovative device significantly expands the hospital's sterile processing output. "Our existing units were not designed for large-scale use," Eric Tesoriero, DO, anesthesiologist for St. Luke's and a collaborator on the project, said in the release. "They could only sterilize about 30 masks at a time." The larger system effectively sterilizes up to 200 masks in just eight minutes—or 25 masks a minute—which has allowed the hospital to now offer mask sterilization to its EMS and paramedic partners.
Broad-spectrum germicidal UV light has been used in hospitals and laboratories for decades to sterilize equipment and is different than conventional UV rays that can penetrate and damage skin cells and cause skin cancer with overexposure. That's why the experts at the World Health Organization (WHO) say the average person should not be using UV light on their skin. "UV lamps should not be used to sterilize hands or other areas of skin as UV radiation can cause skin irritation," they note. The amount of UV rays from sunlight needed to have an effect on the coronavirus is unknown, but experts point to heavy death tolls in sunny areas such Florida, Louisiana, and Singapore, which has seen a recent surge in cases.
Another form of ultraviolet light, however, holds promise. Researchers at Columbia University's Center for Radiological Research are testing lamps that emit continuous low doses of an ultraviolet light known as "far-UVC," which can kill viruses without harming human tissue. "Far-UVC light has the potential to be a 'game changer,'" David Brenner, professor of radiation biophysics and director of the Center for Radiological Research, said in a press release. "It can be safely used in occupied public spaces, and it kills pathogens in the air before we can breathe them in."
Brenner believes the technology may someday be deployed as light fixtures in indoor public spaces such as hospitals, schools, airports, and other transportation hubs. Like the "bug zapper" in use for disinfecting masks at St. Luke's Hospital, UVC lamps in public places may become one of the few potential solutions for preventing the spread of the coronavirus as we move forward. And for more tips on staying safe amid COVID-19, check out 15 Expert Tips for Disinfecting Your House for Coronavirus.