[HN Gopher] New Type of Ultraviolet Light Makes Indoor Air as Sa...
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New Type of Ultraviolet Light Makes Indoor Air as Safe as Outdoors
Author : solarmist
Score : 41 points
Date : 2022-03-27 19:49 UTC (3 hours ago)
(HTM) web link (www.cuimc.columbia.edu)
(TXT) w3m dump (www.cuimc.columbia.edu)
| solarmist wrote:
| I want one in my house.
|
| Link to the actual study.
| https://www.nature.com/articles/s41598-022-08462-z
| dognotdog wrote:
| Wouldn't an open lamp severely degrade all kinds of paints and
| materials that aren't meant to be exposed to UV light? Or does
| the mechanism that supposedly makes the shorter wavelength safe
| for human skin cells apply to all materials?
| closetnerd wrote:
| Me too - I have an air filter (noise/replacing it) but I rather
| this. Do you know where I can get one?? Figure it'd be easy to
| get
| solarmist wrote:
| I want to see refrigerators with this built in as well!
| 01100011 wrote:
| You can buy small ozone generators off aliexpress for your
| fridge if you're paranoid about germs. Then again you may also
| be paranoid about ozone since it's fairly nasty stuff.
| solarmist wrote:
| Yeah, that seems waay worse.
|
| I'm just thinking it would help food keep for longer. I'm not
| worried about germs in particular.
| 8bitsrule wrote:
| FDA article "UV Lights and Lamps: Ultraviolet-C Radiation,
| Disinfection, and Coronavirus" [https://www.fda.gov/medical-
| devices/coronavirus-covid-19-and...]
|
| Nature: "Far-UVC light (222 nm) efficiently and safely
| inactivates airborne human coronaviruses" (2020) PDF
| [https://www.nature.com/articles/s41598-020-67211-2.pdf]
| spsful wrote:
| > About a decade ago, Columbia University scientists proposed
| that a different type of UVC light, known as far-UVC light, would
| be just as efficient at destroying bacteria and viruses but
| without the safety concerns of conventional germicidal UVC.
|
| Why does everyone keep calling this "new"? I've seen it published
| in articles seemingly everywhere within the past few days. It's
| not a new technology; Boeing was prototyping this in their fleet
| several years ago[1].
|
| [1] https://www.cbsnews.com/news/boeings-self-cleaning-
| lavatory-...
| mountainriver wrote:
| Wasn't there another issue with UV light disinfection where it
| creates ozone or something?
| hausen wrote:
| Not in significant quantities. Another study also using Far-UV
| excimer lamps [1] measured levels of less than 0.005 ppm, which
| is far below the 0.05 ppm maximum allowed by the FDA for
| medical devices [2].
|
| [1] https://www.nature.com/articles/s41598-018-21058-w [2]
| https://www.epa.gov/indoor-air-quality-iaq/ozone-generators-...
| solarmist wrote:
| Yup, looks like
|
| " The Ultraviolet spectrum has four wavelengths, (see
| illustration below), labeled: UV-A (400 to 315 nm); UV-B (315
| to 280 nm); very high energy and destructive UV-C (280 to 200
| nm); and Vacuum UV (200 to 100 nm). Only this last wavelength,
| Vacuum UV, is capable of producing ozone."
|
| https://uvresources.com/the-ultraviolet-germicidal-irradiati...
|
| Don't know much about it though.
| modeless wrote:
| Every hospital needs these in every room ASAP.
| alliao wrote:
| 222nm is pretty rare, most are 253nm and many are just fake
| purple LEDs
|
| but this is looking promising, boeing have an interesting article
| on it too I particularly love the toilet solution
|
| https://www.boeing.com/confident-travel/downloads/CAP-3_Disi...
| [deleted]
| solarmist wrote:
| I'd guess it wouldn't be too hard to tune manufacturing for
| lights for that if 253 is already common.
| VBprogrammer wrote:
| If we're talking about LED lights I don't think it's that
| simple. Wavelengths produced are related to the emission
| spectra of the elements which make up the diode junction. If
| I'm remembering my highschool physics correctly.
| solarmist wrote:
| LED would be ideal, but right now I don't care about the
| specifics and just want them to go into mass production.
| GekkePrutser wrote:
| Exactly. It's not a matter of 'tuning'. This is why it took
| so long to get blue LEDs.
|
| Although there are a lot of new options these days, like
| Quantum Dots. If I'm not mistaken quantum dots can only
| convert the light to longer wavelengths though (so lower
| frequencies).
| solarmist wrote:
| Yeah, tuning way the wrong word. But they already exist
| commercially. I just want them To be cheaper and more
| wide spread.
| tormock wrote:
| Isn't an air exchanger better?
| _Microft wrote:
| According to the article, it is not:
|
| "The efficacy of different approaches to reducing indoor virus
| levels is usually measured in terms of equivalent air changes
| per hour. In this study, far-UVC lamps produced the equivalent
| of 184 equivalent air exchanges per hour. This surpasses any
| other approach to disinfecting occupied indoor spaces, where
| five to 20 equivalent air changes per hour is the best that can
| be achieved practically."
|
| For a better understanding, 184 exchanges per hour would mean
| one exchange per 19 to 20 seconds on average. For a room 5m
| wide, that would be a windspeed of 0.25m/s if one actually,
| physically exchanged the air in the room. That would be almost
| (or maybe already) perceptible.
| solarmist wrote:
| Not even close. This would dramatically improve air quality
| (infection wise) in all situations.
| lvs wrote:
| metafunctor wrote:
| I guess it's no surprise that a shorter wavelength kills more
| stuff.
|
| That said, I'm not super convinced that it's safe, if it's not
| something we normally have in our environment... the stuff being
| killed might be you.
| andrewflnr wrote:
| I wonder if turning it on for five minutes every half hour or
| so would be a good compromise risk-wise (assuming it's more
| dangerous than the article wants to believe).
| GekkePrutser wrote:
| I'd be worried about my eyes even more than my skin tbh..
|
| It may very well be safe but I'll need more convincing than
| "yeah your dead skin cells will protect you, don't worry about
| it bro".
| solarmist wrote:
| No, I'm pretty sure it's that shorter wavelengths kill less
| stuff because it can penetrate less. My understanding is this
| research is about finding crossover points where it's still
| deadly to microorganisms, but safe for more complex organisms.
| basch wrote:
| Put it inside duct work
| solarmist wrote:
| Yup, you don't need to worry about tuning the UV. Just stick
| broad spectrum UV (excluding the 100-200nm only) in the duct
| work.
| hn_throwaway_99 wrote:
| Is this uncommon? I had UV disinfectant bulbs installed as
| part of my HVAC installation in my house, seemed pretty
| common.
| solarmist wrote:
| In new installations, but I think it's only been common
| for less than a decade. All older systems will not have
| them unless they were specifically added.
| mrfusion wrote:
| Don't forget that we actually need exposure to germs to train our
| immune systems. We don't want to overdo sanitizing everything.
|
| Look up the hygiene hypothesis.
| samvher wrote:
| Right - I also don't like the idea of something
| indiscriminately killing bacteria on my skin and food.
| Microbiomes in and around our body shouldn't be messed with
| unnecessarily IMO.
| saurik wrote:
| When I see something like this I have to ask "if these people had
| come up with this a decade ago, why did it take them two years
| into a global pandemic to actually try it?".
| solarmist wrote:
| Probably the same discoverability problem music, movies and
| apps suffer.
| tofof wrote:
| Regarding availability and LEDs:
|
| "All commercially available Far-UV 222nm lamps have excimer lamps
| at their core. Excimer lamps are a lighting technology that
| excite a gas using high voltage electric discharges. Different
| gas mixtures generate different frequencies of light. Far-UV
| 222nm light is produced by excimer lamps filled with a mixture of
| krypton (Kr) and chloride (Cl) gas (normally less than 3%
| chloride)."
|
| From https://www.boeing.com/confident-
| travel/downloads/CAP-3_Disi... provided in alliao's comment.
|
| I was able to find one 5W lamp priced at around $1000 and a 20W
| at $1700.
| solarmist wrote:
| Damn. That's... a bit spendy. How much light did they output in
| these experiments?
| amelius wrote:
| That's pricey. Are you sure you didn't buy:
|
| https://en.wikipedia.org/wiki/Extreme_ultraviolet
| andrewflnr wrote:
| > Far-UVC Light _May_ Be Safe for Indoor Use
|
| Emphasis mine. Look, this is promising, but the fact that they
| can only say it may be safe suggests that maybe we should ease
| off with the "zomg deploy it everywhere now!" type of rhetoric. I
| don't think it actually is, but good grief it feels like an
| astroturfing campaign in here right now.
| solarmist wrote:
| There are PLENTY of place you could deploy this without shining
| them directly on people as we continue studying the details,
| but this isn't a single new paper.
|
| Also, from the article. "This reduction was achieved using Far-
| UVC irradiances consistent with current American Conference of
| Governmental Industrial Hygienists threshold limit values for
| skin for a continuous 8-h exposure."
|
| Thus has been under research for a decade now. Plus the effects
| of UV on humans is pretty damn well studied at this point. This
| is just finding the right crossover point that's effective
| against microbes, but no longer dangerous against more complex
| organisms.
|
| I also think we should start retrofitting all ventilation
| systems with UV disinfectants.
|
| My concern is the effect on the microbes on our skin that we
| rely on.
| Natsu wrote:
| Yeah, I agree with this. I've been wishing for a way to
| retrofit our AC with something that uses UV to scrub the air.
| solarmist wrote:
| That already exists. It's relatively common. I'd call your
| servicer and ask about it.
| WalterBright wrote:
| Just put it _inside_ the HVAC system.
| oneepic wrote:
| If I read correctly, the study confirmed it was effective against
| airborne Staph. Not covid, although the latter is the one I
| thought of first. Wonder if it would be hard to get the same
| research study approved to test covid?
| mattbaker wrote:
| From the article:
|
| > "This microbe was chosen because it is slightly less
| sensitive to far-UVC light than coronaviruses, providing the
| researchers with an appropriately conservative model"
|
| This makes me think it would be effective against coronaviruses
| as well.
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(page generated 2022-03-27 23:01 UTC)