Science

Human-safe ultraviolet light used to kill airborne viruses

The technology has been tested on a flu virus
The technology has been tested on a flu virus
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The technology has been tested on a flu virus
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The technology has been tested on a flu virus

For decades, it's been known that broad-spectrum UVC light kills viruses and bacteria by destroying the molecular bonds that hold their DNA together. Unfortunately, it also causes skin cancer and cataracts in people. Now, however, scientists have discovered that a narrow spectrum of UVC – known as far-UVC – can eradicate airborne viruses without harming humans.

Led by Prof. David J. Brenner, researchers from Columbia University had previously demonstrated that far-UVC light could kill MRSA (methicillin-resistant Staphylococcus aureus) bacteria without damaging human skin. MRSA commonly causes surgical wound infections.

In their latest study, the team set out to see if overhead far-UVC lights could also kill airborne viruses. In order to do so, they released aerosolized H1N1 virus (which is a strain of the flu) into a test chamber, where it was exposed to very low doses of the light. As a control, they also released H1N1 into the chamber without the light exposure.

What the scientists found was that the far-UVC effectively eradicated the viruses, approximately as efficiently as a conventional broad-spectrum UVC germicidal light. Unlike such a light, though, the far-UVC isn't dangerous to people.

"Far-UVC light has a very limited range and cannot penetrate through the outer dead-cell layer of human skin or the tear layer in the eye, so it's not a human health hazard," says Brenner. "But because viruses and bacteria are much smaller than human cells, far-UVC light can reach their DNA and kill them."

If further studies support the team's findings, it is hoped that overhead far-UVC lights could ultimately be used to stop the spread of airborne viruses in public spaces such as hospitals, doctors' offices, schools, airports and airplanes. As an added bonus, unlike vaccinations, far-UVC should be effective against even newly-emerging strains of such viruses.

A paper on the research was recently published in the journal Scientific Reports.

Source: Columbia University Irving Medical Center

3 comments
guzmanchinky
Excellent news
sugamari
yes indeed - news to counteract the discovery that flu virus' can transmit through open air
marc49
UVB light has been used to sterilize areas, clothing and water. I suppose that UVC would work even better. A more important fact may be that sun exposure per se enhances the immune system and prevents flu before it takes hold. This can be easily seen by the fact that colds and flu occur in winter, whether in the Southern or Northern hemisphere. The mechanism may be vitamin D, which is not very available in the winter. The salubrious effects of sunlight extend far beyond halting flu, however. Consider the following: A 20-year Swedish study demonstrated a 23% reduced risk of all-cause death among those women who used sunbeds (tanning beds). Overall, women who actively sought the sun had half the risk of death compared with those who avoided the sun. Here are more facts: •A Spanish study shows that women who seek the sun have one-eleventh the hip-fracture risk as those who avoid sun. •Men working outdoors have half the risk of melanoma as those working indoors. •Women who avoid the sun have 10-times the risk of breast cancer as those who seek the sun. •Women who sunbathe regularly have half the risk of death during a 20-year period compared to those who stay indoors. •Sun exposure increases nitric oxide production, which leads to a decrease in heart disease risk. •Sun exposure dramatically improves mood through the production of serotonin and endorphin. Sun exposure increases production of BDNF, essential to the nervous system. More information: http://sunlightinstitute.org