9 ms·

Far-UVC light: A tool to control the spread of airborne-mediated microbial

95 points by gjvc 5y ago

ISL 5y ago
The article has an interesting changelog in the Competing-Interests section, which led to this correction: https://www.nature.com/articles/s41598-021-97682-w https://www.nature.com/articles/s41598-021-97682-w
stevespang 5y ago
mackatsol 5y ago
Ok, I’m convinced. So how / where can I find such a light to use in our apartment lobby (for example)?
- bluGill 5y ago
  I'd go for a HEPA air filter instead, some also have UV light inside
- giarc 5y ago
  If you search my username in this thread, you'll see another comment by myself. I can't remember the product name, but there exists a company that makes a UV light system that swaps out for the usual fluorescent light you see in most commercial buildings. I'm not affiliated with the company at all.
geoduck14 5y ago
This is really cool! At the start of the pandemic, I researched UVC light as a mechanism to kill the virus. I do want to point out a minor point: >However, the widespread use of germicidal ultraviolet light in public settings has been very limited because conventional UVC light sources are a human health hazard, being both carcinogenic and cataractogenic conventional UVC is generated by mercury light bulbs and are carcinogenic and cataractogenic BUT about 10 years ago, it became practical to use frequency doubling in LEDs to generate light really close to the mercury light - the LEDs are not carcinogenic and cataractogenic. When you read about UVC effects, you should check what type of light source they are using (mercury vs LED) Also, it is the advancements in silicon manufacturing that has made it cheaper to make new and different LEDs - such as these "far-UVCs". It is pretty legit! There is "a lot" of research demonstrating effectiveness of "conventional UVC", but not a lot on "far-UVC". One of the limitations on both is the shadow effect... got to go. I'll elaborate if there is interest
- detaro 5y ago
  > BUT about 10 years ago, it became practical to use frequency doubling in LEDs to generate light really close to the mercury light - the LEDs are not carcinogenic and cataractogenic. What makes the LED light not dangerous that way? As far as I understand, what makes UVC effective is also what makes it dangerous.
  - Gibbon1 5y ago
    I did the same as the parent. The answer is that mercury based UV lamps produce a spiky broad spectrum including emission lines really where you don't want them. And not very much at the frequency that is most effective at destroying RNA/DNA. 220nm is important because it's very effective at cross linking thymine. UV LEDs can be manufactured to produce a very narrow spectrum centered on 220nm. So with an LED the total amount of UV produced is much less and doesn't include problematic frequencies that cause eye and tissue damage. Supposedly, I don't work in this space. Note most UV LED's aren't suitable for sterilization. If it comes in a plastic case and costs 30 cents, it's certainly not.
    - ecesena 5y ago
      > UV LEDs can be manufactured to produce a very narrow spectrum centered on 220nm Does anyone know of any manufacturer? I don't think they exist yet?
      - mrsulaj 5y ago
        Full disclosure: I'm the founder of UVX Inc., a University of British Columbia company integrating Far-UVC technology into smart devices. Unfortunately, current state-of-the-art UV LEDs do not produce enough power at the 220nm wavelength to be commercially viable. The current state-of-the-art uses KrCl excimer lamps to generate this light, with optical filters to eliminate spillage in the undesired frequencies (> 230nm).
        Gibbon1 5y ago
causality0 5y ago
The very careful wording makes me somewhat suspicious. For example, they focus on the skin safety of far-UVC, but what about long term effects on the cornea?
- geoduck14 5y ago
  Skin safety was a common concern for conventional UVC, and far-UVC has been anticipated to solve this problem so it is focused here. They are saying the light waves can't penetrate the fist layer of skin... which presumably includes the first layer of eye-ball skin. If true, there shouldn't be any impact to the cornea over time
  - tranzudao 5y ago
    I think this is an oversimplification. The cornea differs quite a bit from skin histologically. Even if light does stop at the first layer of the cornea - the question is how? The problem typically found with UV wavelengths is opacification of the cornea/lens (cataracts). I have no idea if this is the case for the specific wavelength in the paper - but it’s definitely worth more discussion
  - causality0 5y ago
    All their citations have to do with skin penetration. The one that even mentioned the cornea only did so in reference the amount of UVC reaching the lens. These authors make claims which, while possibly true, are not found in their cited literature. For example, they say far UVC cannot penetrate the tear layer. Their citation doesn't say that. The citation says it's unlikely to damage human cells between 10 and 25 micrometers in diameter. The tear layer averages three micrometers in thickness, and it does not contain the absorptive proteins responsible for the shallow flesh penetration depth. This is shoddy science. Chronic exposure to 240nm light causes keratopathies. 222nm is not 240nm of course but I would demand a better study before I agreed to 40+ hours a week of exposure to far-UVC.
savant_penguin 5y ago
Wow now this is a convincing result https://media.springernature.com/full/springer-static/image/art%3A10.1038%2Fs41598-018-21058-w/MediaObjects/41598_2018_21058_Fig1_HTML.jpg?as=webp https://media.springernature.com/full/springer-static/image/...
potiuper 5y ago
The article links to https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5552051/ https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5552051/ that states "Therefore, penetration of far-UVC ~200-nm light through the cornea to the lens is Predicted to be essentially zero (15)." 15 is titled: "UV absorbance of the human cornea in the 240- to 400-nm range." Further, the main claim is "in microbes that are much smaller in size than human cells [less than 1 μm in diameter, compared to the diameter of typical human cells ranging from about 10–25 μm], [far UVC] is strongly absorbed by the proteins in the cytoplasm of human cells and is drastically attenuated before reaching the human cell nucleus" DNA and other proteins are known to be more affected by 220 nm due to absorption peaks than 254 nm. From https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradiation#Safety https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradia... : 'Another potential danger is the UV production of ozone, which can be harmful when inhaled. Lamps designed to release UV and higher frequencies are doped so that any UV light below 254 nm wavelengths will not be released, to minimize ozone production.' The lights are most applicable placed at the at the coils and drain pans of cooling systems as 'forced air systems by design impede line-of-sight, thus creating areas of the environment that will be shaded from the UV light.' https://pubmed.ncbi.nlm.nih.gov/28941399/ https://pubmed.ncbi.nlm.nih.gov/28941399/ concluded 280 nm worked better than 265 nm for water disinfection.
- fsh 5y ago
  All deep UV wavelengths are energetic enough to break chemical bonds and the cross sections have quite non-trivial wavelength dependences. The authors of the article claim that 222 nm has a much shorter absorption length in tissue than 254 nm. This would drastically reduce the intensity that can reach the living cells under the outer layers of the skin.
41b696ef1113 5y ago
Is it standard practice for commercial HVAC to have some kind of UV light/ozone/X pathogen killing mechanism somewhere in the ducts? Or would that only be installed on a HEPA style system going for a certified clean environment? I would naively think that exposing the forced airflow to the treatment would be both simpler and safer than installing a system into every room with people.
- bradknowles 5y ago
  We have UV filters on our HVAC units here at our house, in addition to the whole-house HEPA filters. They’re expensive, but if you have a lot of allergies, IMO they are well worth the extra cost.
- DannyBee 5y ago
  It's not standard because you can just use filters. Keep in mind the filters have to be able to filter the dead pathogens anyway (usually same size) or else you are breathing them, which isn't great either. Better than live ones for sure, but not great. As for UV, you can add it to either residential or commercial easily (some preschools and schools I've visited added them in the past year). It doesn't make sense to install in every room, as you say. On ozone, see https://www.epa.gov/coronavirus/air-cleaners-hvac-filters-and-coronavirus-covid-19 https://www.epa.gov/coronavirus/air-cleaners-hvac-filters-an... and the section on ozone.
  - cipheredStones 5y ago
    What's the risk from dead pathogens - immune overreaction? It's a screwball idea, but I wonder if there might actually be health benefits to reliably killing pathogens without filtering them out of the air - sort of like low-dose inactivated-agent vaccines for everything you would have actually been exposed to otherwise.
  - bradknowles 5y ago
    UV can kill stuff that gets through the filters. Even HEPA filters go down to objects of a certain size, and some viruses are smaller than that. But UV can kill even those smaller viruses.
1-6 5y ago
Bacteria is a lot more difficult to kill because of the size. This is great for viruses though. I've always wondered about the effectiveness of UVC, humidity, and ozone for the control of COVID.
rapjr9 5y ago
It does sound as they say "promising" but when do they do the big, decades long double blind, randomized, controlled study of long term effects? What if you have a wound in your skin, does it become cancerous because the live cells are exposed to far UVC light? What does it do to plastics? Do humans get sick easier if they are living in a sterile environment? Does it kill plants? Far UVC is not a natural phenomena on Earth.
- SideburnsOfDoom 5y ago
  As I understand it, the usual design of systems that use UV light to kill viruses do not simply shine it into the room like a ceiling light; rather there's a box with a UV light in it, and a fan to draw air through that box.
bratwurst3000 5y ago
Seems like a way to risky idea… gut feeling. And there are problems. First the uv has to reach the virus. If there are shadows its over. Its super hard to ilumate a room perfektly…. And may i propose an alternative. Use a hepa filter that changes the air in the room at a rate that would make in impossible to have much virus in the air… also not that easy but imho way safer than UVC
- musingsole 5y ago
  Eh, not techy and sparkly enough. It won't convince the laypeople that they're safe enough if the only palpable aspect of the system is a slight breeze.
  - abecedarius 5y ago
    As kind of an echo of radu_floricica's comment upthread: dismissing some X because some other people allegedly will have unreasonable concerns, that's another disease of discourse we get too much of. I wish people would restrain themselves from bringing up that kind of alleged obstacle until after getting to some kind of rough consensus at the object level. It's like a recipe for "We can't ever improve anything unless, somehow, magically, there's already common knowledge of the fix." The object-level talk is necessary to getting to common knowledge!
- radu_floricica 5y ago
  How many ways I hate your comment? let me count the ways. 1. Somebody comes with a potentially awesome idea, you have a gut feeling it's risky, and start looking for confirmations of your gut feeling. Way to #hit on somebody else's initiative. 2. "The virus" (we all know we aren't talking about tuberculosis here) is airborne, which means it'll float around. If there are shadows it's not "over", it what scenario it would even mean anything for shadows to be game over? An instantaneous flash once? 3. An alternative is not an argument. Hepa filters work, and I completely agree that we should be using them a lot more but: 3.1 We aren't using them a lot more, so for some reason they don't fix the problem, so alternate solutions are very welcome 3.2 There's room for more than one took in a toolkit, for reasons too obvious to get into. ---------------- Now why am I taking the time to write a comment 5x the length of yours? Because you're merely doing in a somewhat more obvious and inexperienced way what society has been doing for... at least a couple dozen years. Anything new is risky, we should carefully study side effects and only when it's clear there aren't any we're allowed to move forward. This is especially true for medical tech, but it's part of a larger disease that's in the same constellation with NIMBY, regulatory capture and taxi medallions being worth a million. Covid made it obvious that a lot of emperors didn't wear clothes. We could have had mRNA vaccines quite a bit earlier - and I'm sure the companies involved would have been perfectly happy to make money from them. But no, there had to be a pandemic for regulatory agencies to even consider approving such new tech. We could have had WFH ten years ago, the tech was here. It took barely weeks for IT departments and worflows to adapt. But no, managers had to negotiate in the strictest terms for even one day a week of WFH, because it's Something That Is Not Done. And you have a gut feeling that it's risky tech, and I get triggered.
tagoregrtst 5y ago
“[…] far-UVC light cannot penetrate even the outer (non living) layers of human skin or eye; ” Without reading their previous reference, this doesn't make sense. If it doesn't reach the outer layers, what’s blocking the light? Also, I seriously doubt this wont cause cataracts in the long term. By Wiki, light < 200 nm is absorbed by O2. The light proposed by the authors is 207< \lambda < 222, so about as energetic as UV can be and not be blocked by the atmosphere. Ill take their word that it cant make it past the layer of dead skin. But what protects the cornea? Just the very thin layer of tears? Turn up the HVAC air exchange rate please! There are many other benefits to that.
jcims 5y ago
Pretty interesting video demonstrating UV (not sure what part of the spectrum) killing microbes. https://youtu.be/sJVtNsezGUI https://youtu.be/sJVtNsezGUI Really a great channel, some of the best microphotography out there.
gene-h 5y ago
If this does indeed take off, we may expect the next trend in fashion to be clothing with with stripes and other features that fluoresce under said UVC light.
pfyy 5y ago
I have a question. Does anybody know why we keep our indoor light sources uva / uvb free ? I know that too much UVA/B light seems to be carciogenic, but a small amount of it, especially UVB seems to be beneficial to human and still kills germs, especially covid [1] The positive effects are a) vitamin d production b) germicide The negative effects are c) lower energy efficiency in the visible spectrum (watt per visible light produced) d) negative effect on the eye e) carciogenic For indoor keeping of reptiles UVB light seems to be needed [2] As far as i've read, for indoor planting, UV light seems to beneficial as well, for example it increases the production of THC [3] Why should we, as humans, be different ? [1]Ratnesar-shumate, S.; Williams, G.; Green, B.; Krause, M.; Holland, B.; Wood, S.; Bohannon, J.; Boydston, J.; Freeburger, D.; Hooper, I.; Beck, K.; Yeager, J.; Altamura, L. A.; Biryukov, J.; Yolitz, J.; Schuit, M.; Wahl, V.; Hevey, M.; Dabisch, P. Simulated Sunlight Rapidly Inactivates SARS-CoV-2 on Surfaces. J. Infect. Dis. 2020, 222 (2), 214–222.Google Scholar https://sci-hub.st/https://doi.org/10.1093/infdis/jiaa274 https://sci-hub.st/https://doi.org/10.1093/infdis/jiaa274 [2] https://en.wikipedia.org/wiki/Ultraviolet#UVB https://en.wikipedia.org/wiki/Ultraviolet#UVB [3] https://vanessa-nielsen.com/cannabis-plants-uv-light/ https://vanessa-nielsen.com/cannabis-plants-uv-light/
- weaksauce 5y ago
  if i had to guess there are a few reasons they don't do this... the first and most important reason is manufacturers have and will optimize for the main benefit of a product. the main product here is light. heat came as a negative byproduct of traditional incandescent lights and heat is something to minimize to lengthen the life of an led bulb. another possibility is that if it were widespread it could cause some negative outcomes of people sitting too closely to a source of it and potentially exposing the companies to legal issues. not a lawyer and they might be able to shield themselves from that liability with well written disclaimers though. Along with inertia from the incandescent bulbs not emitting that wavelength... the most likely reason is that they don't want to spend the money on researching how safe it is and how to cost effectively make them like that though.
- defaultname 5y ago
  UV A/B is oxidizing, which is why plastics left outside degrade rapidly, discoloration occurs, etc. It's bad for your eyes, bad for your skin in excess, and creates ozone in the air which is an environmental pollutant. Normal indoor plants have no need for UV at all. Nor do most food plants -- greenhouse glass blocks UV, for instance.
ozfive 5y ago
Where can I buy one?
- deleted 5y ago
  [deleted]
- mrsulaj 5y ago
  Full disclosure: I'm the founder of UVX Inc., a University of British Columbia company integrating Far-UVC technology into smart devices. We're looking to ship out units within the next month, here is where you can learn more (https://www.uvxinc.com https://www.uvxinc.com). I'd love to hear your thoughts/feedback!
  - ozfive 5y ago
    It seems as though you are targeting companies with your contact us for further information buttons. I'd like to find out how much this would cost to install in a home? Are you B2B only?
    - mrsulaj 5y ago
      Our existing product is B2B, yes, but we got a lot of interest from consumers too and are considering a consumer product line (for which we're doing customer interviews to get insights/feedback). If you have 20-mins to share your thoughts, we'd love to hear from you :)
deleted 5y ago
[deleted]
ecesena 5y ago
This is a good TED talk on Far UVC: https://www.ted.com/talks/david_brenner_a_new_weapon_in_the_fight_against_superbugs https://www.ted.com/talks/david_brenner_a_new_weapon_in_the_...
ddxxdd 5y ago
My questions with this line of research are always: 1) How do you deal with the toxic ozone gas that's produced, and 2) How do you prevent eye damage from happening when you look at the device?

95 points by gjvc 5y ago

ISL 5y ago

The article has an interesting changelog in the Competing-Interests section, which led to this correction: https://www.nature.com/articles/s41598-021-97682-w https://www.nature.com/articles/s41598-021-97682-w

stevespang 5y ago

mackatsol 5y ago

Ok, I’m convinced. So how / where can I find such a light to use in our apartment lobby (for example)?

bluGill 5y ago
I'd go for a HEPA air filter instead, some also have UV light inside
giarc 5y ago
If you search my username in this thread, you'll see another comment by myself. I can't remember the product name, but there exists a company that makes a UV light system that swaps out for the usual fluorescent light you see in most commercial buildings. I'm not affiliated with the company at all.

geoduck14 5y ago

This is really cool! At the start of the pandemic, I researched UVC light as a mechanism to kill the virus. I do want to point out a minor point: >However, the widespread use of germicidal ultraviolet light in public settings has been very limited because conventional UVC light sources are a human health hazard, being both carcinogenic and cataractogenic conventional UVC is generated by mercury light bulbs and are carcinogenic and cataractogenic BUT about 10 years ago, it became practical to use frequency doubling in LEDs to generate light really close to the mercury light - the LEDs are not carcinogenic and cataractogenic. When you read about UVC effects, you should check what type of light source they are using (mercury vs LED) Also, it is the advancements in silicon manufacturing that has made it cheaper to make new and different LEDs - such as these "far-UVCs". It is pretty legit! There is "a lot" of research demonstrating effectiveness of "conventional UVC", but not a lot on "far-UVC". One of the limitations on both is the shadow effect... got to go. I'll elaborate if there is interest

detaro 5y ago
> BUT about 10 years ago, it became practical to use frequency doubling in LEDs to generate light really close to the mercury light - the LEDs are not carcinogenic and cataractogenic. What makes the LED light not dangerous that way? As far as I understand, what makes UVC effective is also what makes it dangerous.
- Gibbon1 5y ago
  I did the same as the parent. The answer is that mercury based UV lamps produce a spiky broad spectrum including emission lines really where you don't want them. And not very much at the frequency that is most effective at destroying RNA/DNA. 220nm is important because it's very effective at cross linking thymine. UV LEDs can be manufactured to produce a very narrow spectrum centered on 220nm. So with an LED the total amount of UV produced is much less and doesn't include problematic frequencies that cause eye and tissue damage. Supposedly, I don't work in this space. Note most UV LED's aren't suitable for sterilization. If it comes in a plastic case and costs 30 cents, it's certainly not.
  - ecesena 5y ago
    > UV LEDs can be manufactured to produce a very narrow spectrum centered on 220nm Does anyone know of any manufacturer? I don't think they exist yet?
    - mrsulaj 5y ago
      Full disclosure: I'm the founder of UVX Inc., a University of British Columbia company integrating Far-UVC technology into smart devices. Unfortunately, current state-of-the-art UV LEDs do not produce enough power at the 220nm wavelength to be commercially viable. The current state-of-the-art uses KrCl excimer lamps to generate this light, with optical filters to eliminate spillage in the undesired frequencies (> 230nm).
      - Gibbon1 5y ago

causality0 5y ago

The very careful wording makes me somewhat suspicious. For example, they focus on the skin safety of far-UVC, but what about long term effects on the cornea?

geoduck14 5y ago
Skin safety was a common concern for conventional UVC, and far-UVC has been anticipated to solve this problem so it is focused here. They are saying the light waves can't penetrate the fist layer of skin... which presumably includes the first layer of eye-ball skin. If true, there shouldn't be any impact to the cornea over time
- tranzudao 5y ago
  I think this is an oversimplification. The cornea differs quite a bit from skin histologically. Even if light does stop at the first layer of the cornea - the question is how? The problem typically found with UV wavelengths is opacification of the cornea/lens (cataracts). I have no idea if this is the case for the specific wavelength in the paper - but it’s definitely worth more discussion
- causality0 5y ago
  All their citations have to do with skin penetration. The one that even mentioned the cornea only did so in reference the amount of UVC reaching the lens. These authors make claims which, while possibly true, are not found in their cited literature. For example, they say far UVC cannot penetrate the tear layer. Their citation doesn't say that. The citation says it's unlikely to damage human cells between 10 and 25 micrometers in diameter. The tear layer averages three micrometers in thickness, and it does not contain the absorptive proteins responsible for the shallow flesh penetration depth. This is shoddy science. Chronic exposure to 240nm light causes keratopathies. 222nm is not 240nm of course but I would demand a better study before I agreed to 40+ hours a week of exposure to far-UVC.

savant_penguin 5y ago

Wow now this is a convincing result https://media.springernature.com/full/springer-static/image/art%3A10.1038%2Fs41598-018-21058-w/MediaObjects/41598_2018_21058_Fig1_HTML.jpg?as=webp https://media.springernature.com/full/springer-static/image/...

potiuper 5y ago

The article links to https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5552051/ https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC5552051/ that states "Therefore, penetration of far-UVC ~200-nm light through the cornea to the lens is Predicted to be essentially zero (15)." 15 is titled: "UV absorbance of the human cornea in the 240- to 400-nm range." Further, the main claim is "in microbes that are much smaller in size than human cells [less than 1 μm in diameter, compared to the diameter of typical human cells ranging from about 10–25 μm], [far UVC] is strongly absorbed by the proteins in the cytoplasm of human cells and is drastically attenuated before reaching the human cell nucleus" DNA and other proteins are known to be more affected by 220 nm due to absorption peaks than 254 nm. From https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradiation#Safety https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradia... : 'Another potential danger is the UV production of ozone, which can be harmful when inhaled. Lamps designed to release UV and higher frequencies are doped so that any UV light below 254 nm wavelengths will not be released, to minimize ozone production.' The lights are most applicable placed at the at the coils and drain pans of cooling systems as 'forced air systems by design impede line-of-sight, thus creating areas of the environment that will be shaded from the UV light.' https://pubmed.ncbi.nlm.nih.gov/28941399/ https://pubmed.ncbi.nlm.nih.gov/28941399/ concluded 280 nm worked better than 265 nm for water disinfection.

fsh 5y ago
All deep UV wavelengths are energetic enough to break chemical bonds and the cross sections have quite non-trivial wavelength dependences. The authors of the article claim that 222 nm has a much shorter absorption length in tissue than 254 nm. This would drastically reduce the intensity that can reach the living cells under the outer layers of the skin.

41b696ef1113 5y ago

Is it standard practice for commercial HVAC to have some kind of UV light/ozone/X pathogen killing mechanism somewhere in the ducts? Or would that only be installed on a HEPA style system going for a certified clean environment? I would naively think that exposing the forced airflow to the treatment would be both simpler and safer than installing a system into every room with people.

bradknowles 5y ago
We have UV filters on our HVAC units here at our house, in addition to the whole-house HEPA filters. They’re expensive, but if you have a lot of allergies, IMO they are well worth the extra cost.
DannyBee 5y ago
It's not standard because you can just use filters. Keep in mind the filters have to be able to filter the dead pathogens anyway (usually same size) or else you are breathing them, which isn't great either. Better than live ones for sure, but not great. As for UV, you can add it to either residential or commercial easily (some preschools and schools I've visited added them in the past year). It doesn't make sense to install in every room, as you say. On ozone, see https://www.epa.gov/coronavirus/air-cleaners-hvac-filters-and-coronavirus-covid-19 https://www.epa.gov/coronavirus/air-cleaners-hvac-filters-an... and the section on ozone.
- cipheredStones 5y ago
  What's the risk from dead pathogens - immune overreaction? It's a screwball idea, but I wonder if there might actually be health benefits to reliably killing pathogens without filtering them out of the air - sort of like low-dose inactivated-agent vaccines for everything you would have actually been exposed to otherwise.
- bradknowles 5y ago
  UV can kill stuff that gets through the filters. Even HEPA filters go down to objects of a certain size, and some viruses are smaller than that. But UV can kill even those smaller viruses.

1-6 5y ago

Bacteria is a lot more difficult to kill because of the size. This is great for viruses though. I've always wondered about the effectiveness of UVC, humidity, and ozone for the control of COVID.

rapjr9 5y ago

It does sound as they say "promising" but when do they do the big, decades long double blind, randomized, controlled study of long term effects? What if you have a wound in your skin, does it become cancerous because the live cells are exposed to far UVC light? What does it do to plastics? Do humans get sick easier if they are living in a sterile environment? Does it kill plants? Far UVC is not a natural phenomena on Earth.

SideburnsOfDoom 5y ago
As I understand it, the usual design of systems that use UV light to kill viruses do not simply shine it into the room like a ceiling light; rather there's a box with a UV light in it, and a fan to draw air through that box.

bratwurst3000 5y ago

Seems like a way to risky idea… gut feeling. And there are problems. First the uv has to reach the virus. If there are shadows its over. Its super hard to ilumate a room perfektly…. And may i propose an alternative. Use a hepa filter that changes the air in the room at a rate that would make in impossible to have much virus in the air… also not that easy but imho way safer than UVC

musingsole 5y ago
Eh, not techy and sparkly enough. It won't convince the laypeople that they're safe enough if the only palpable aspect of the system is a slight breeze.
- abecedarius 5y ago
  As kind of an echo of radu_floricica's comment upthread: dismissing some X because some other people allegedly will have unreasonable concerns, that's another disease of discourse we get too much of. I wish people would restrain themselves from bringing up that kind of alleged obstacle until after getting to some kind of rough consensus at the object level. It's like a recipe for "We can't ever improve anything unless, somehow, magically, there's already common knowledge of the fix." The object-level talk is necessary to getting to common knowledge!
radu_floricica 5y ago
How many ways I hate your comment? let me count the ways. 1. Somebody comes with a potentially awesome idea, you have a gut feeling it's risky, and start looking for confirmations of your gut feeling. Way to #hit on somebody else's initiative. 2. "The virus" (we all know we aren't talking about tuberculosis here) is airborne, which means it'll float around. If there are shadows it's not "over", it what scenario it would even mean anything for shadows to be game over? An instantaneous flash once? 3. An alternative is not an argument. Hepa filters work, and I completely agree that we should be using them a lot more but: 3.1 We aren't using them a lot more, so for some reason they don't fix the problem, so alternate solutions are very welcome 3.2 There's room for more than one took in a toolkit, for reasons too obvious to get into. ---------------- Now why am I taking the time to write a comment 5x the length of yours? Because you're merely doing in a somewhat more obvious and inexperienced way what society has been doing for... at least a couple dozen years. Anything new is risky, we should carefully study side effects and only when it's clear there aren't any we're allowed to move forward. This is especially true for medical tech, but it's part of a larger disease that's in the same constellation with NIMBY, regulatory capture and taxi medallions being worth a million. Covid made it obvious that a lot of emperors didn't wear clothes. We could have had mRNA vaccines quite a bit earlier - and I'm sure the companies involved would have been perfectly happy to make money from them. But no, there had to be a pandemic for regulatory agencies to even consider approving such new tech. We could have had WFH ten years ago, the tech was here. It took barely weeks for IT departments and worflows to adapt. But no, managers had to negotiate in the strictest terms for even one day a week of WFH, because it's Something That Is Not Done. And you have a gut feeling that it's risky tech, and I get triggered.

tagoregrtst 5y ago

“[…] far-UVC light cannot penetrate even the outer (non living) layers of human skin or eye; ” Without reading their previous reference, this doesn't make sense. If it doesn't reach the outer layers, what’s blocking the light? Also, I seriously doubt this wont cause cataracts in the long term. By Wiki, light < 200 nm is absorbed by O2. The light proposed by the authors is 207< \lambda < 222, so about as energetic as UV can be and not be blocked by the atmosphere. Ill take their word that it cant make it past the layer of dead skin. But what protects the cornea? Just the very thin layer of tears? Turn up the HVAC air exchange rate please! There are many other benefits to that.

jcims 5y ago

Pretty interesting video demonstrating UV (not sure what part of the spectrum) killing microbes. https://youtu.be/sJVtNsezGUI https://youtu.be/sJVtNsezGUI Really a great channel, some of the best microphotography out there.

gene-h 5y ago

If this does indeed take off, we may expect the next trend in fashion to be clothing with with stripes and other features that fluoresce under said UVC light.

pfyy 5y ago

I have a question. Does anybody know why we keep our indoor light sources uva / uvb free ? I know that too much UVA/B light seems to be carciogenic, but a small amount of it, especially UVB seems to be beneficial to human and still kills germs, especially covid [1] The positive effects are a) vitamin d production b) germicide The negative effects are c) lower energy efficiency in the visible spectrum (watt per visible light produced) d) negative effect on the eye e) carciogenic For indoor keeping of reptiles UVB light seems to be needed [2] As far as i've read, for indoor planting, UV light seems to beneficial as well, for example it increases the production of THC [3] Why should we, as humans, be different ? [1]Ratnesar-shumate, S.; Williams, G.; Green, B.; Krause, M.; Holland, B.; Wood, S.; Bohannon, J.; Boydston, J.; Freeburger, D.; Hooper, I.; Beck, K.; Yeager, J.; Altamura, L. A.; Biryukov, J.; Yolitz, J.; Schuit, M.; Wahl, V.; Hevey, M.; Dabisch, P. Simulated Sunlight Rapidly Inactivates SARS-CoV-2 on Surfaces. J. Infect. Dis. 2020, 222 (2), 214–222.Google Scholar https://sci-hub.st/https://doi.org/10.1093/infdis/jiaa274 https://sci-hub.st/https://doi.org/10.1093/infdis/jiaa274 [2] https://en.wikipedia.org/wiki/Ultraviolet#UVB https://en.wikipedia.org/wiki/Ultraviolet#UVB [3] https://vanessa-nielsen.com/cannabis-plants-uv-light/ https://vanessa-nielsen.com/cannabis-plants-uv-light/

weaksauce 5y ago
if i had to guess there are a few reasons they don't do this... the first and most important reason is manufacturers have and will optimize for the main benefit of a product. the main product here is light. heat came as a negative byproduct of traditional incandescent lights and heat is something to minimize to lengthen the life of an led bulb. another possibility is that if it were widespread it could cause some negative outcomes of people sitting too closely to a source of it and potentially exposing the companies to legal issues. not a lawyer and they might be able to shield themselves from that liability with well written disclaimers though. Along with inertia from the incandescent bulbs not emitting that wavelength... the most likely reason is that they don't want to spend the money on researching how safe it is and how to cost effectively make them like that though.
defaultname 5y ago
UV A/B is oxidizing, which is why plastics left outside degrade rapidly, discoloration occurs, etc. It's bad for your eyes, bad for your skin in excess, and creates ozone in the air which is an environmental pollutant. Normal indoor plants have no need for UV at all. Nor do most food plants -- greenhouse glass blocks UV, for instance.

ozfive 5y ago

Where can I buy one?

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mrsulaj 5y ago
Full disclosure: I'm the founder of UVX Inc., a University of British Columbia company integrating Far-UVC technology into smart devices. We're looking to ship out units within the next month, here is where you can learn more (https://www.uvxinc.com https://www.uvxinc.com). I'd love to hear your thoughts/feedback!
- ozfive 5y ago
  It seems as though you are targeting companies with your contact us for further information buttons. I'd like to find out how much this would cost to install in a home? Are you B2B only?
  - mrsulaj 5y ago
    Our existing product is B2B, yes, but we got a lot of interest from consumers too and are considering a consumer product line (for which we're doing customer interviews to get insights/feedback). If you have 20-mins to share your thoughts, we'd love to hear from you :)

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ecesena 5y ago

This is a good TED talk on Far UVC: https://www.ted.com/talks/david_brenner_a_new_weapon_in_the_fight_against_superbugs https://www.ted.com/talks/david_brenner_a_new_weapon_in_the_...

ddxxdd 5y ago

My questions with this line of research are always: 1) How do you deal with the toxic ozone gas that's produced, and 2) How do you prevent eye damage from happening when you look at the device?