Ultraviolet light kills pathogens such as COVID-19 but is also a danger to human beings. But what if there was a version of UV light that killed pathogens without affecting people?
It turns out there is. Krypton chloride (KrCl) excimer lamps radiate light at a frequency of 222 nm, also known as Far-UVC, which is safe for people but still just fine for killing airborne pathogens similar to COVID-19:
This comes from a recent study in Nature, which didn't use actual COVID-19 pathogens but did use something similar enough that the researchers believe their results apply to COVID-19. Further research is still necessary to confirm this.
It's worth noting that this isn't really anything new. For example, Far UV Technologies would be delighted to sell you one of their broad range of krypton excimer lamps starting at the low, low price of $2,499. Amazon will sell you one for $1,699 with free shipping. There are others out there too, all of which promise to sanitize your environment safely and quickly.
Personally, I'd like a small, battery operated unit for $19.95 that I could put in a pocket then use wherever I happened to be. However, this appears not to be technologically feasible just yet. That's a shame.
Have you thought of trying bigger pockets?
What we need is a tiny version of this we can snap on to our teeth.
A long version that we can shove up Trump’s ass.
omg, Bluto Barksalot was right! We can stuff laser beams into our veins! This changes everything!
"How do we get such low prices? Volume, volume, volume!" If these lamps do come into routine use, people will find a way to build them far more cheaply. They need high-voltage electronics, which has become more buildable with new devices.
Both the appearance of the chart and the analysis itself remind me of The Andromeda Strain.
Xenon is better...
https://youtube.com/clip/UgkxADyoSSnVFk_udQTzgT8xra3erEU68zSa
Too bad common fluorescent lights don't do the trick. Schools would be safe as hell.
But "is there a way that we could somehow, get it, in the body?"
It is not "Nature".
It is "Scientific reports", a journal by Nature publishing group.
URL is confusing since it reads nature dot com
for thos who don't know, "Nature" is a top quality journal, while "Scientific reports" is an author pays journal that woud publish all kind of crap.
Page charges aren't the same as a vanity press. Scientific Reports is a refereed journal that rejects papers that don't meet high standards. Scientific Reports is the 6th most-cited journal in the world.
I have seen garbge in "Scientific reports" too. The "page charges", i.e. author pay, does reduce the quality of review.
Plenty of garbage in Nature (and Science).
Also, page charges, open access charges, etc. are pretty much standard everywhere. If not those, there are color figure charges, so basically authors pay something in all scientific journals.
It could affect quality of editorial decisions (aka crap journals), but it's unclear to me how it could affect reviewers who are not paid anything anyway.
It is the editorial decisions that decide the quality of the journal. And while Nature and Science are far from perfect (and getting further), they are far batter than Scientific reports.
At this point, and assuming the technology works, I would think that devices like this would be good for places like Dr/dentist offices. I’m surprised I hadn’t heard about it before.
When I was a kid the barbershops had a box with a glowing blue light to sterilize the clippers and scissors when not in use.
You have no right to subject me to UVC without my permission. You're infringing on my personal freedom. I don't like UV, and you can use it in your house but you have no right to use it in public places where I might be exposed to it.
Not only that, but it's against my religion, so if you deploy it in public places you're violating not only my individual freedom, but also my First Amendment freedom of religion guarantees. Furthermore, you have no right to spend my tax dollars on something that's against my religion. And also, you can't use it an any schools my kids might attend, since they are minors under my protection and are subject to my healthcare decisions, not yours.
And it probably turns kids gay as well. Just another Deep State attempt to convert us to the coastal elite agenda.
Ok, so this is a fact; elites have been monitoring us with their CRTs for years. Most people had those monitors in their homes. It has finally been exposed and only the Republicans are protecting us from CRTs. You can look it up.
What the hell is KrCl? I thought Kr was a noble gas that didn't react with anything. I guess it makes a temporary bond when energized.
222nm is a very energetic photon, about 5.58eV.
https://en.wikipedia.org/wiki/Excimer_lamp
In my world that is a soft x-ray. The K-alpha line for Li is at 52eV. This is the lowest energy line we look at in x-ray spectroscopy.
I guess the reason it is considered safe is that photons in this range are absorbed incredibly easily. Presumably, the first couple of nanometers of dead skin or even the tears over the lens in your eye would absorb them. Still, makes me nervous.
Probably a big part of the cost is the exit window. Because these photons are absorbed so easily it is difficult to make a material that will isolate the active, excited gas on the inside from the outside air and still allow the photons to pass through.
Clearing the air of the virus is a great idea. For a DIY solution look at the Corsi-Rosenthal box.
https://en.wikipedia.org/wiki/Corsi–Rosenthal_Box
I keep promoting an idea that should eliminate almost all the virus load cheaply, that is using a simple scrubber. Similar to a filter box, a scrubber uses a fan to draw air through a small box. Instead of a filter, the box contains a bunch of simple plastic shapes (kind of like nested whiffle balls) that provide a huge surface area in a small volume. A pump sprays water throughout this box. The huge surface area and misted water capture nearly everything in the air. For a classroom or office you could use simple cardboard tubes with perforations to deliver clean air at the ceiling and draw in used air near the floor. The idea is that the air flow should be top to bottom, not cross-wise. If anyone exhales virus particles they are pulled to the floor and washed out. This would take care of not only COVID but the common cold, flu and allergens.
Aha, KrCl really is a fleetingly briefly made compound.
https://en.wikipedia.org/wiki/Excimer
Excimers are "molecules" that combine a filled-shell (e.g., noble gas) atom in an excited (i.e., not ground state) with another reactive species, usually a halogen.
The generally accepted boundary these days between UV and x-rays is 100 nm.
Krypton is a noble gas with a closed shell of electrons that make it very stable. Alas Chlorine is an extremely reactive element that can under the some conditions can react with Krypton to form short livedmolecules.
Sounds good. Mandate these in buildings along with ventilation then call it a day.
Safety is relative.
In this case, the 222 nm wavelength does not penetrate into the skin or eye very far, so for the most part does not damage living cells, unlike, say, the typical 254 nm germicidal lamp.
A pre-covid study:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5552051/
Not used mainly because of costs. There would also have to be extended studies on effects on surfaces, etc., to see if any other problems would arise using 222 nm.
Germicidal lamps are great to kill off bacteria. Typically, not nearly as effective on viruses, so higher doses required. The "nature" study here uses a bacteria, not a virus as the test pathogen. It is not a study of effectiveness on viruses, let alone on SARS-COV-2. That is mentioned in the paper, but they reference a different study using a different set up.
Link to another paper (pdf) looking at effects of 22nm on a variety of viruses (overview):
https://iuva.org/resources/covid-19/Far%20UV-C%20Radiation-%20Current%20State-of%20Knowledge.pdf
All of this is promising, especially if costs come down and filters blocking light above 230 nm stay effective (damaging light). And as long as other problems don't show up.
There is also a potential ozone generating problem. While far UVC radiation may not penetrate the skin, it can still generate ozone (O3) which is nasty to living things and reacts with other compounds to make more nasty things.
Or, people could just get vaccinated like we do against the measles.
I would want to know a lot more about the physics and biophysics of this. Air has strong absorption bands below 300 nm, so the flux may be vastly different near the source vs. far from the source. (This is why germicidal lamps at 254 nm usually work only at close range.) How close can you be to the lamp before skin or eye damage occurs? How far away can a surface be from the lamp before it's ineffective?
Exposure to radiation at 220 nm may be relatively safe from a biological point of view, but there is definitely a risk of damage to polymers. There is the direct generation of color centers (this is why clear plastics become yellow and brittle with exposure to sunlight or UV), and possibly indirect damage due to generation of ozone, which then reacts with the polymer. (I can't find a high-resolution absorption spectrum for oxygen at this wavelength, so I don't know if ozone generation is significant or not.)
So KrCl lamps do generate ozone: https://www.uvccleaningsystems.com/cm/dpl/downloads/content/1107/Ozone-222nm_lamps.pdf
Although much less than 254 nm germicidal lamps.
Actually, it's been commercially available for over a decade. Two years ago, I made several comments about how there are portable UV-C lamps to make bottled water potable. I own one. Requires lithium AA batteries. UV-C doesn't travel far, so it's not a practical use in the way you're envisioning. Nonetheless, if you want one: https://www.rei.com/product/847549/katadyn-steripen-ultra-uv-water-purifier
Have Fox Trumpropagandists sneered "Trump was right again!" yet?
I want one in the form of a hat.
You can get air purifiers with UV lamps inside them.
Assuming it’s true that it’s perfectly safe, it still looks like it takes about 5 minutes to clear the air. If I’m standing next to a covid-positive person that is breathing, coughing, or sneezing, it’s not gonna hang around in the air for 5 minutes to get killed off. It’s gonna be in my airways within seconds. I guess it wouldn’t make things worse, but it might give people a false sense of security.