Through portals with Far UVC light can help clean clothes, skin and even air in busy areas of cruise ships.
On July 29, JetBlue Airways unveiled the Honeywell UV Cabin System, a robot-sized robot with arms that extend across the seats to sweep the cabin and treat aircraft surfaces. It can disinfect the entire cabin in about 10 minutes.
Troutbeck, a historic 250 acre retreat in New York’s Hudson Valley, upgraded all of the resort’s HVAC systems with a new HEPA filter system that contains UV light for additional germ control.
The New York public transportation system, the Metropolitan Transportation Authority, worked with Columbia University to test UV light in vehicles and other fixed locations such as break rooms and operations centers.
While companies continue to use ultraviolet light to disinfect their aircraft cabins, hotels, subway cars, and cruise ships, the average American is skeptical. How can light kill the corona virus?
What is UV light?
Ultraviolet light is a band of electromagnetic radiation with higher energies and shorter wavelengths than visible light, which according to the International Ultraviolet Association makes it invisible to the human eye.
There are four subcategories for UV light based on their wavelengths: UVA, UVB, UVC and vacuum UV.
UVA wavelengths are longest and range between 400 and 315 nanometers. Most black light falls into this category, except for a small part that falls into the purple spectrum, which is why people who use it see a purple color.
On the other side of the spectrum, vacuum UV has the shortest wavelengths, which are between 100 and 200 nanometers.
Airlines, companies, hotels and hospitals use UVC light specifically to disinfect surfaces and kill viruses that chemicals may overlook. UVC light falls between 280 and 200 nanometers.
Can UVC light kill the corona virus? How?
Jim Malley, professor of civil and environmental engineering at the University of New Hampshire, said that germicidal UVC light has been used to disinfect surfaces and kill viruses for decades.
While studies have not yet confirmed whether UVC light can kill SARS-CoV-2, the virus that causes COVID-19, several studies have shown that it can kill other viruses, including influenza and other seasonal corona viruses.
But how can a light kill a virus? One theory, Malley said, is that UVC light damages the virus’ RNA so that it can no longer reproduce and become infected. It can also damage the protein that coats the virus and prevent it from binding to a host cell.
Typical germicidal UVC light kills viruses at a wavelength of 254 nanometers. However, all viruses are different and some respond to shorter or longer wavelengths. They also require a different UV dose, which is measured based on light intensity and exposure time.
“The thing about viruses and germs is that they’re not one thing,” Malley said. “Some are very resilient, so they need a high UV dose, others are more vulnerable so they can take a low UV dose.”
If all measurements match, UVC light can kill 99.9% of the viruses and bacteria.
One limit to UVC light is that it only disinfects what it sees. Sometimes the light source has to be repositioned several times to get every angle into a room. Depending on the size, light intensity and exposure time, the disinfection of a room can also take a few cycles.
Science is meticulous.
“The (UV) light we are talking about cannot be seen because it works against a virus that is far too small to see,” said Malley. “It’s like painting with an invisible brush.”
Is UVC light dangerous?
If UVC light can damage RNA in viruses, it can also damage DNA in cells that are on human skin.
The International Agency for Research on Cancer has classified ultraviolet radiation as carcinogenic to humans, which means that it can cause cancer. The American Cancer Society also said that UV light can cause premature aging and signs of damage such as wrinkles, dermis, liver spots, actinic keratosis, and sun elastosis.
According to Malley, UV light can also be harmful to the human eye and in particular damage the cornea. According to the ACS, this could result in clouding of the eye lens or tissue growth on the surface of the eye, which can impair vision.
For this reason, many companies go one step further to protect consumers. Some companies even offer protective equipment such as suits and goggles, while others develop products that keep out the light.
“If it doesn’t harm your skin or eyes, it’s not the right amount of UV energy to kill viruses and bacteria,” said Mark Beeston, vice president of sales and marketing for Vioguard, a UVC lighting technology company.
However, a recent study suggests that there may be a spectrum of UVC light that kills viruses but is not harmful to humans.
Researchers at Columbia University’s Irving Medical Center found that more than 99.9% of seasonal coronaviruses in droplets in the air were killed when exposed to a wavelength known as 222 nanometers far UVC light. The results were published in the journal Nature in June.
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According to the study, distant UVC light cannot penetrate either the tear layer of the eye or the outer layer of the dead cells of the skin. This means that it is unable to reach and damage living cells in the body.
“Because it is safe to use in occupied spaces such as hospitals, buses, airplanes, trains, train stations, schools, restaurants, offices, theaters, gyms and wherever people gather indoors, UVC light can be combined with others Measures are used … to limit the transmission of SARS-CoV-2 and other viruses, “said study lead author David Brenner, director of the Center for Radiological Research at Columbia University’s Irving Medical Center.
The UV market is like the “Wild West”: most products are “garbage”
Good UVC lighting devices are difficult to perfect, but it seems that many companies are throwing their hats in the ring as consumers look for more ways to disinfect their homes.
“It’s a wild west rodeo, the gold rush. Everyone goes up the mountains to dig gold,” Beeston said.
Malley sees ten to twenty ads a day and calls most of these products “garbage”.
He said that most devices that kill viruses and promote safe use are typically marketed to hospitals or commercial laboratories. These devices can range from $ 1,000 to $ 4,000. The cheapest product Malley has seen and that actually works starts at $ 400.
The Metropolitan Transportation Authority is expanding a pilot program to use some form of ultraviolet light to kill the virus that causes COVID-19. (June 12)
“If something is like $ 100 or $ 200 … it probably won’t work,” he said. “Many of these things are easy to manufacture and sell, but nobody is bothered by the research.”
Although some companies receive marketing approval from the Food and Drug Administration or the Environmental Protection Agency, there is no official certification or approval from a government agency that confirms the effectiveness of a product.
Experts are urging customers to do some research before buying a UVC light device. Does it have studies to back it up? Does it appear in hospitals, laboratories, or other commercial establishments? What is the light wavelength, the recommended dose and at what distance?
Malley and Beeston recommend contacting the manufacturer and asking these questions if the answers are not immediately clear.
Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.
Health and patient safety coverage in the U.S. TODAY is partially made possible through a grant from the Masimo Foundation for Ethics, Innovation, and Healthcare Competition. The Masimo Foundation makes no editorial contributions.
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