12 ms·
New type of ultraviolet light makes indoor air as safe as outdoors
- metafunctor 5y agoI 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.
- GekkePrutser 5y agoI'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".
- rocqua 5y agoThe idea is apparently that the wet layer on your eyes is enough to protect your cornea. See my comment here for sourcing: https://news.ycombinator.com/item?id=30829785 https://news.ycombinator.com/item?id=30829785
- GekkePrutser 5y agoHmmm so if I don't blink for too long I expose it? I don't know, I'm not worried about corona anymore but much more about this :)
- andrewflnr 5y agoI 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).
- solarmist 5y agoNo, 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 5y agoPut it inside duct work
- solarmist 5y agoYup, 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 5y agoIs this uncommon? I had UV disinfectant bulbs installed as part of my HVAC installation in my house, seemed pretty common.
- solarmist 5y agoIn 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.
- thedougd 5y agoTwo challenges with making this work well. 1) Not destroying plastic and rubber components exposed to the light. 2) Ensuring whatever is passing through the light receives enough exposure. Often they're better at keeping evaporator coils clean than cleaning the air.
- solarmist 5y agoOh? It makes sense, but I hadn't heard that. Have your read about that somewhere?
- at_a_remove 5y agoI have a rather serious photosensitivity disorder, so this sort of thing is vaguely terrifying.
- londons_explore 5y agoDoesn't this end up destroying plastics and producing ozone and various other gasses from broken down molecules from everything in the room?
- solarmist 5y agoI want one in my house. Link to the actual study. https://www.nature.com/articles/s41598-022-08462-z https://www.nature.com/articles/s41598-022-08462-z
- closetnerd 5y agoMe 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
- dognotdog 5y agoWouldn'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?
- solarmist 5y agoYeah be safer for many kinds of materials, it should, but I’m not sure what the thresholds for those materials are specifically.
- deleted 5y ago[deleted]
- tormock 5y agoIsn't an air exchanger better?
- _Microft 5y agoAccording 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 5y agoNot even close. This would dramatically improve air quality (infection wise) in all situations.
- tormock 5y agoI think that they are ignoring other factors.
- angry_octet 5y agoIt is better, because it doesn't create interesting chemistry. There are all sorts of products produced from normal pollutants and cleaning agents (sodium hypochlorite) with the extra energy from UV.
- alliao 5y ago222nm 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_Disinfection_with_Far-UV.pdf https://www.boeing.com/confident-travel/downloads/CAP-3_Disi...
- solarmist 5y agoI’d guess it wouldn’t be too hard to tune manufacturing for lights for that if 253 is already common.
- VBprogrammer 5y agoIf 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 5y agoLED would be ideal, but right now I don’t care about the specifics and just want them to go into mass production.
- GekkePrutser 5y agoExactly. 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 5y agoYeah, tuning was the wrong word. But they already exist commercially. I just want them To be cheaper and more wide spread.
- deleted 5y ago
- modeless 5y agoEvery hospital needs these in every room ASAP.
- saurik 5y agoWhen 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?".
- alliao 5y agoby admitting it's airborne I suspect it is a major upheaval on scope due to responsibilities of employers providing a safe working space.. hence the reluctance. it's too bad, we have careerest in every discipline, and somehow people in tenured positions didn't have the projection they needed to overcome all the noise.
- solarmist 5y agoProbably the same discoverability problem music, movies and apps suffer.
- saurik 5y agoCan you elaborate? I mean, this is the people who came up with the idea, not some end user.
- solarmist 5y agoI mean an academic is inherently going to be cautious about putting forth something like this until they are throughly convinced from a public health perspective. But from an outside perspective there are likely plenty of lower stakes ways to take advantage of this. The example that occurs to me over was seeing UV disinfectants for tableware in restaurants 20 years ago in South Korea.
- syntheweave 5y agoJust look at how the medical orthodoxy has behaved: first solving the wrong problem by putting emphasis on skin contact and droplet spread. Vague messaging about masking. Little messaging about ventilation. And now denial and downplaying about long COVID. Scientific answers were there, but our institutions preferred to normalize their beliefs into their preexisting comfort zone and dismiss anything else with a "cool story bro". They only seem to learn after the blood has been spilled.
- tofof 5y agoRegarding 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_Disinfection_with_Far-UV.pdf 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.
- andrewflnr 5y ago> 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 5y agoThere 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 5y agoYeah, I agree with this. I've been wishing for a way to retrofit our AC with something that uses UV to scrub the air.
- WalterBright 5y agoJust put it inside the HVAC system.
- oneepic 5y agoIf 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 5y agoFrom 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.
- solarmist 5y agoI want to see refrigerators with this built in as well!
- 01100011 5y agoYou 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.
- 8bitsrule 5y agoFDA article "UV Lights and Lamps: Ultraviolet-C Radiation, Disinfection, and Coronavirus" [https://www.fda.gov/medical-devices/coronavirus-covid-19-and-medical-devices/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 https://www.nature.com/articles/s41598-020-67211-2.pdf]
- mountainriver 5y agoWasn’t there another issue with UV light disinfection where it creates ozone or something?
- solarmist 5y agoYup, 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-irradiation-uv-c-wavelength/ https://uvresources.com/the-ultraviolet-germicidal-irradiati... Don’t know much about it though.
- hausen 5y agoNot 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 https://www.nature.com/articles/s41598-018-21058-w [2] https://www.epa.gov/indoor-air-quality-iaq/ozone-generators-are-sold-air-cleaners https://www.epa.gov/indoor-air-quality-iaq/ozone-generators-...
- bawolff 5y agoJust being a factor of ten away from being "dangerous", is not exactly what i would call "far"
- lvs 5y ago222 nm?? No way jose. Free radicals don't just stay where you generate them. Even if the UV dose is minimal below a few layers of cells, it doesn't mean that radical damage does not reach live epidermal layers. Just using ventilation is a lot safer and has no real downsides.
- mrfusion 5y agoDon’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 5y agoRight - 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.
- zuminator 5y agoOTOH this is a type of ultraviolet exposure that we would also receive from sunlight. At least as claimed, it's not doing anything different to our microbiomes than just going outside would do.
- bradknowles 5y agoNo, it's not. You might see UV-A or UV-B in normal sunlight, but not UV-C. It is blocked by the atmosphere. That's why it's so dangerous to terrestrial life as diverse as viruses, bacteria, and human beings, as well as others. UV-C is not something we have had frequent exposure to over the millennia, and so this is something we are not adapted to handle.
- zuminator 5y agoUgh, you're absolutely correct! I retract my prior comment; thanks for the correction. And not to detract from my being flat-out wrong, but it should be noted that it's claimed that the specific 222nm wavelength of far-UVC used by these devices is not energetic enough to penetrate the skin or lens of the eyes [0][1]. [0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5552051/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5552051/ [1] https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0201259 https://journals.plos.org/plosone/article?id=10.1371/journal...
- spsful 5y ago> 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-uses-uv-light-to-kill-germs/ https://www.cbsnews.com/news/boeings-self-cleaning-lavatory-...
- bongoman37 5y agoIt is like Hacker News articles. Sometimes an article will have an upvote or two and few comments and sink from news, and then it gets reposted a couple of years later and there's hundreds of votes and tons of discussions.
- _nalply 5y agoWhy? Probably this makes advertisement more successful.
- helsinkiandrew 5y agoI think what's new is that they can add 'kills COVID' and it will be republished on news sites with little thought.
- IanCal 5y agoThe study looks like it's about the efficacy of putting commercially available lights in real world rooms. Really it's just the headline that says "new type". I think in a colloquial sense, this is fair I think. They are pretty new. If it's something some people have been trialling within the last few years, that's pretty new to me. Especially in the context of "a light".
- ianai 5y agoWow, a simple search on Amazon even pulled up far uvc lamps.
- a1371 5y ago"safe" in this context is virus safe. Can have a pretty good application for places where virus transmission is an issue, as long as people like me don't feel an unease about being bombarded with UV 10 hours a day. When I think of "Safe" for air, I also think of PM2.5 and other airborne compounds. A more permanent fix to make the air fully safe is improving building ventilation.
- mjevans 5y agoIMO, as an armchair opinion, the LEED certification craze is much of the issue. * https://en.wikipedia.org/wiki/LEED https://en.wikipedia.org/wiki/LEED There's an almost blind focus on one dimension of a multi-dimensional problem. Yes, buildings should be designed to be more energy and environmentally efficient; where it makes sense. However there are many assumptions in 'building code' that evolved around implicit properties in the materials and methods used in the past. A more comprehensive evaluation would consider numerous factors and choose trade-offs. What is the (exterior) difference in impact between using different quantities and combinations of building materials? How do those materials need to be maintained or replaced over the life of the building? Over it's demolition? Can they be recycled or otherwise recovered? How do the used materials and shapes effect the operational energy for the intended use of the building (over the intended, and likely, lifetimes)? It looks like a 2014 update to LEED finally 'considers indoor environmental quality'. "... the IEQ category addresses thermal, visual, and acoustic comfort as well as indoor air quality." However my opinion is that they've put the cart before the horse. Surely you've seen office environments where someone doesn't like 'how cold' the building is; so they use a personal heater to blow directly on themselves. Or utilize an air filtration system for one room because it's impossible to clean the ventilation ducts. It also fails to consider containment of emissions from chemical / cleaning or other smelly areas. The acoustic angle is also critically important for apartments and condos. One of _the_ major reasons I and many others have grown to hate living in them revolves around __noise__. There are many memes about marching bands and various other sadistic neighbors on any adjacent side, particularly upstairs. If you want people to _want_ to move to apartments and condos, then they need to be built so they're desirable. That includes 'cave of solitude' level of audio isolation. Fresh air that doesn't have the cooking or laundry smells; or worse the trash chute leaking out because someone didn't setup the pressure system correctly. It also includes no more free-for-all parking and enough spaces for the cars people will bring with them from the suburbs. (Which might be as many as 2 per adult on average!) The car angle might be solved at the same time as municipal parking, if a big enough, and well secured enough, lot exists as an IO/interface with the surrounding areas. That level of thinking combined with people-mover sidewalks along pedestrian arterials will help us move towards 'Cave of Steel' like cities.
- Meerax 5y agoEdit to preface: Forgive the potentially naive question but -what happens when some form of bacteria (or something) evolves in a way that renders it hardy enough to survive far-uvc? The article mentioned it's ability to destroy superbugs..just wondering if any thought has been given to unintended side effects like this.
- solarmist 5y agoI mean that’s like considering the ability for an organism to survive bleach. It’s not impossible, but my understanding is would be as difficult as building trinary /fuzzy logic CPUs. Basically reinventing it from the ground up. It’s hard to evolve against instant death. When the atomic level chemistry/physics is against you, you’re fighting a losing battle.
- fennecs 5y agoI’m not that worried about random bacteria and microbes, people are covered in them. As long as it isn’t too much, we don’t need our buildings to be 100% sterile, except in certain locations like a Hospital. Mould, micro plastics, pm 2.5, microfibres, car pollution seem far more concerning, and we need to do something about those.
- angry_octet 5y agoBefore you rush out and install powerful UV everywhere, think about the chemistry, and if you're chemistry topped out at Chem 101, maybe get an actual aerosol chemist. "Unintended Consequences of Air Cleaning Chemistry" https://pubs.acs.org/doi/10.1021/acs.est.1c02582 https://pubs.acs.org/doi/10.1021/acs.est.1c02582
- deleted 5y ago[deleted]
- radu_floricica 5y ago> as safe as outdoors Ah, forgot about Covid. I'm in Bucharest, and "as safe as outdoors" is pure masochism. Kids, stay away from corruption and incompetence, it gives cancer and lots of other stuff as well.
- deleted 5y ago[deleted]
- manmal 5y agoSounds like a great thing to add to operating rooms and generally in high risk (with known antibiotic resistant bacteria infestation) hospitals.
- rocqua 5y agoIf this is safe because of a layer of dead skin, I am not sure its a good idea to put this in operating rooms where they may have exposed inner flesh. Imagine having a sunburn, but on your intestines.
- manmal 5y agoHaving (indirectly) lost a grandfather to complications following an infection during hip surgery, I think it’s at least worth looking into. So many people die because hospitals can’t prevent infections. Why not radiate the room very strongly for a few minutes before surgery?
- ggm 5y agoDo it once per room, at night with a mobile unit. Does it reduce risk to zero? No, but it resets the risk to a consistent floor, every day. Others have done the "inside HVAC, its been sold for decades" thing already.
- Animats 5y agoIs there some fundamental reason that UV-C lamps have to be so expensive? Or is it a lack of demand problem?
- contingencies 5y agoThey have a perception as specialist/medical so premium is the order of the day. The prior lamps were heavy and inefficient. Newer LEDs are preferred but they are not made by that many companies, or until recently anyway. And many of the new entrants have crap longevity. Furthermore, sourcing issues compounded over COVID. There are also unique design challenges mechanically for UVC. Just some of which are efficacy is inversely proportional to distance and time, and you need 100% line of sight to have any effect at all...
- sbierwagen 5y agoUVC lamps require exotic UV-transparent glasses. Soda-lime glass won't pass UV.
- tailrecursion 5y agoIf the UV light kills 98% of microbes, what happens with the remaining 2% UV-resistant microbes, are they now the fittest?
- c3534l 5y agoWhy not just put the UV lights in the air ducts instead of point them at people?
- supernova87a 5y agoEven if the lights are effective, I am skeptical enough of LED quality control that I don't exactly jump to trust that the ones I get aren't leaking out the side bands (off-color basically) and sending adjacent more harmful wavelengths into my eyes. Especially if those LEDs start to be sold on Ebay and come from who-knows-what factories (which there already are).
- ciphol 5y ago1) Doesn't an LED have only a single band gap, determined by its main materials, thus no "side bands"? 2) Even if other wavelengths are produced, they just need to be produced in lesser quantities than in say sunlight. 3) #2 will require regulation and enforcement, but so do numerous other consumer devices - did you worry about your CFL leaking mercury?
- supernova87a 5y ago1. Not if it relies on phosphors or dopants to achieve the desired emission profile. 2. I don't think that the standard for a safe environment at home or at work is that you are exposed to the wavelengths and intensities equal to direct sunlight?
- quantum_magpie 5y agoThe lamps aren't LED and you can't get to UV-C wavelengths in LEDs. Also 222nm is deep into the DNA damage spectrum so they aren't safe for living organisms anyway.
- knighthack 5y agoI couldn't stop thinking of zombies while reading this. In Dying Light, ultraviolet light wards off the zombies. If we assume that a) the imminent singularity/zombie apocalypse of modern reality will be preceded by infectious airborne viruses, and b) this new UV light has protective/cleansing effects that "reduce the level of indoor airborne microbes by more than 98%", c) that "that far-UVC light can kill the COVID virus, other human coronaviruses, influenza, and drug-resistant bacteria", then hey presto: we've got a potential counter-weapon that can be modified to work against the zombie apocalypse.
- londons_explore 5y agoHow many kilowatts of light is required to have this effect? If it's a kilowatt per room, then humans simply don't have enough electricity production to deploy this widely.
- lesgobrandon 5y ago
- rob_c 5y agoReading the article as most university press releases should be, this looks like a grab for some of the government money to 'explain away' the current covid situation and mindset. Just think, if this was cost-effective/safe/efficient/didn't-have-side-effect-X-such-as-breaking-down-plastics we'd likely be using it already...
- _pmf_ 5y ago
- rocqua 5y agoThey have a diagram explaining the theory of why this is skin safe (doesn't penetrate the outer skin layer). But I see no reasoning as to why this is eye-safe. I would expect that the cornea is more fragile than the outer layer of dead skin. One nice upside of using this in-situ is that it cleans surfaces just as much as it cleans the air. So just using this in the ducts / air filters is not as effective.
- rocqua 5y agoAs per this article: https://www.nature.com/articles/s41598-020-67211-2 https://www.nature.com/articles/s41598-020-67211-2 > ... far-UVC light has a range in biological materials of less than a few micrometers, and thus it cannot reach living human cells in the skin or eyes, being absorbed in the skin stratum corneum or the ocular tear layer. The ocular tear layer, according to 30s of googling, is just the wet layer over your eyes (the stuff that turns into tears when you produce to much of it). So the idea is that this is eye-safe because the radiation gets absorbed by the small layer of wetness on your eyes.
- ahahahahah 5y ago> They have a diagram explaining the theory of why this is skin safe (doesn't penetrate the outer skin layer). But I see no reasoning as to why this is eye-safe. It's described why it is eye-safe in literally the same diagram.
- foxyv 5y agoI kind of wonder if COVID-19 is a blessing in disguise. Something to kick the world in the pants and prepare for much worse diseases, whether man-made or natural. Will technology like better air treatment, MRNA vaccines, and better emergency preparedness save our butts some day? Probably not, but it is nice to think that there is some silver lining.