Different wavelength of UV light, measured here in nanometers, can penetrate skin down to different layers. The farther down into the skin these wavelengths go, the more harm they can cause.
(Credit: “Far UV-C Radiation: Current State-of Knowledge,” published by the International UV Association in 2021)
A specific wavelength of ultraviolet (UV) light is not only extremely effective at killing the virus which causes COVID-19, but is also safer for use in public spaces, finds new CU Boulder research.
The study, published this month in Applied and Environmental Microbiology, is the first to comprehensively analyze the effects of different wavelengths of UV light on SARS-CoV-2 and other respiratory viruses, including the only wavelength safer for living beings to be exposed to without protection.
The findings, which the authors refer to as a “game changer” for UV light use, could lead to new affordable, safe and highly effective systems for reducing viral spread in crowded public spaces like airports and concert venues.
“Of almost every pathogen we have ever studied, this virus is one of the easiest, by far, to kill with UV light,” said senior author Karl Linden, professor of environmental engineering. “It takes a very low dose. This indicates that UV technology could be a really good solution for protecting public spaces.”
UV light is naturally emitted by the sun, and most forms are harmful to living beings—as well as microorganisms, like viruses. This light can get absorbed by the genome of an organism, tie knots in it and prevent it from reproducing. These harmful wavelengths from the sun, however, are filtered out by the ozone layer before they reach the surface of the earth.
Some common products, like fluorescent tube lamps, use human-engineered UV light, but a white phosphorous coating on the inside protects people from the UV rays.
“When we take that coating off, we can emit those wavelengths, and they can be harmful for our skin and our eyes—but they can also kill pathogens,” said Linden.
Hospitals already use UV light technology to disinfect surfaces in spaces when there are no people in them, utilizing robots which can shine UV light in operating and patient rooms between uses.
And many gadgets on the market today clean everything from cell phones to water bottles with UV light. But safety protocols are still being developed by the FDA and EPA. Linden cautions against using any personal or “germicidal” devices in which a person is exposed to UV light.
The new findings are unique, he said, because they hit the sweet spot between UV light that is relatively safe for humans and harmful for viruses, especially the one that causes COVID-19.
“This can be a game changer for the public use of UV light in indoor spaces,” said Linden.
Death by exposure
For the study, Linden and his team compared different UV wavelengths side-by-side using standardized methods developed across the UV light industry.
“We thought, let’s come together and make a definitive statement on what UV exposure is required to kill off SARS-CoV-2,” said Linden. “We wanted to make sure that if UV light is being used to control disease, you’re delivering the right dose that’s protective of human health and human skin, but also going to be killing off these pathogens.”
The opportunity to do this kind of work is rare, as there are extremely rigorous safety standards required to work with SARS-CoV-2. So Linden and Ben Ma, postdoctoral researcher in Linden’s research group, collaborated with virologist Charles Gerba at the University of Arizona, at a lab cleared to work with the virus and its variants.
The researchers found that while the virus was quite susceptible to UV light in general, a specific wavelength of Far ultraviolet-C, at 222 nanometers, was particularly effective. Created by what’s known as a krypton chloride excimer lamp, fueled by molecules moving between different states of energy, this wavelength is very high energy. Therefore, it’s able to inflict greater viral protein and nucleic acid damage to the virus compared to other UV-C devices, as well as be blocked by the very top layers of human skin and eyes—meaning that it has limited to no detrimental health effects at doses that are capable of killing off viruses.
“Not only is it safe, it’s also the most effective,” said Linden.
The role of UV disinfection today
UV light in various forms has been used widely since the early 20th century to disinfect water, air and surfaces. As early as the 1940s, it was used to reduce the transmission of tuberculosis in hospitals and classrooms, by shining the light at the ceiling to disinfect air as it circulated throughout the room. Today, it’s used not only in hospitals, but in some public bathrooms and airplanes when there are no people in those spaces.
In a recent White Paper published by the International UV Association, “Far UV-C Radiation: Current State-of Knowledge,” which accompanies the new study, Linden and co-authors argue that this safer wavelength of Far UV-C light could serve as a key mitigation measure against the current and future pandemics, in addition to improved ventilation, mask wearing and vaccination.
Linden imagines systems that could either cycle on and off in indoor spaces to routinely clean the air and surfaces, or create an ongoing, invisible barrier between teachers and students, customers and service workers, and people in spaces where social distancing is not possible, to disinfect the air.
UV light disinfection can even rival the positive effects of improved indoor ventilation by providing the equivalent protection of increased air changes per hour within a room. It’s also much cheaper to install UV lights than to upgrade an entire HVAC system.
“There is an opportunity here to save money and energy while protecting public health in the same way. It’s really exciting,” said Linden.
Original Article: Specific UV light wavelength could offer low-cost, safe way to curb COVID-19 spread
More from: University of Colorado at Boulder | University of Arizona | University of North Carolina at Chapel Hill
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
Far ultraviolet-C
- May the 4th Corrupt You: Star Wars-themed haunted house will open for one dayon April 27, 2024 at 8:01 am
May the horror be with you? On May 4, there will be what might just be the world's first Star Wars-themed haunted house in Manayunk. Lincoln Mill Haunted House will change into space mode for what ...
- 14 Best Non-Comedogenic Sunscreens for Even the Most Acne-Prone Peepson April 26, 2024 at 6:37 am
On the flip side, if you have oily or acne-prone skin, you’re better off selecting mattifying or ultra-lightweight sunscreens that don’t leave you feeling like a grease pool midday. The Starface Clear ...
- Aquaphor is the MVP of my head-to-toe skin care — here are all the ways to use iton April 26, 2024 at 6:11 am
Aquaphor is my holy grail skin care product, and it goes beyond the ointment. I’m sharing my 5 favorite products and all the ways to use them.
- Machine learning and extended reality used to train welderson April 25, 2024 at 10:30 am
Ever since the ancient Egyptians hammered two pieces of gold together until they fused, the art of welding has continuously progressed.
- Plato's burial place finally revealed after AI deciphers ancient scroll carbonized in Mount Vesuvius eruptionon April 25, 2024 at 9:02 am
Researchers used AI to decipher an ancient papyrus that includes details about where Greek philosopher is buried.
Go deeper with Google Headlines on:
Far ultraviolet-C
[google_news title=”” keyword=”far ultraviolet-C” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]
Go deeper with Bing News on:
UV light disinfection
- UV-C Disinfection Robot Market CAGR of 32% Importance of Net Promoter Score Measuring and Improving Customer Loyaltyon April 25, 2024 at 8:28 pm
The robots developed with UV-C light, are used as a part of the consistent cleaning cycle, which results in preventing and reducing the spread of communicable diseases caused by viruses, bacteria, and ...
- Far UV-C: New ultraviolet technology kills 99.99% germs in 25 minson April 25, 2024 at 8:29 am
We have been using ultraviolet light in treating disease for more than 100 years, is it time for a safer option?
- New UV air disinfection technology could help protect against health care infections, possibly the next pandemicon April 24, 2024 at 3:10 pm
Experts are working on a new type of ultraviolet light called far-UVC that could be highly effective for reducing airborne transmission of diseases such as COVID-19 and influenza--as well as surface ...
- New ultraviolet light air disinfection technology could help protect against healthcare infections and even the next pandemicon April 24, 2024 at 3:07 pm
“Compounding the problem, and a major limitation of traditional cleaning and disinfection strategies ... “Conventional UV light has been used widely in hospitals and prisons, but it can ...
- Spring cleaning for clean breathing: How you can improve indoor air quality in your homeon April 24, 2024 at 1:03 pm
A routine tuneup found biological growth in my home's HVAC unit. Here what I did to get rid of it, plus expert tips for improving indoor air quality.
Go deeper with Google Headlines on:
UV light disinfection
[google_news title=”” keyword=”nano factory” num_posts=”5″ blurb_length=”0″ show_thumb=”left”]