[HN Gopher] Can you kill coronavirus with UV light?
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Can you kill coronavirus with UV light?
Author : tartoran
Score : 82 points
Date : 2020-03-28 19:44 UTC (3 hours ago)
(HTM) web link (www.bbc.com)
(TXT) w3m dump (www.bbc.com)
| augustt wrote:
| Does anyone know how LED-based UVC lamps like [1] with >300 LEDs
| can sell on Amazon for less than $100 when it appears the
| individual LEDs are fairly expensive? On DigiKey/Mouser the
| cheapest price I can find is still more than $1/LED [2].
|
| [1] https://www.amazon.com/2020-Newest-Germicidal-Lamp-
| Light/dp/...
|
| [2] https://www.mouser.com/Optoelectronics/LED-Lighting/LED-
| Emit...
| nimbius wrote:
| hey! relevant anecdotal data here. I work in an automotive repair
| garage. Anyone who has to drive a vehicle dropped off by a
| customer has to make sure its been UV sanitized first. We drape a
| 40 watt CFL UV lamp from your rearview mirror, put your floor
| mats on your windshield and rear window, and cover the windows
| with scratch mats for 35 minutes. After the timer goes off, a big
| blue sticker goes on your window. We then do it all over again
| before we give the truck or car back to you.
|
| We had 2 ozone generators we were using (normally to remove
| cigarette smoke from car seats) but they take hours. the bulbs
| are cheaper and faster!!
| makomk wrote:
| Big Clive over on YouTube was complaining the other day that
| certain sellers of these lights had taken part of his video
| warning against exposing skin to them and used it to claim they
| were skin-safe when promoting them for use against the
| coronavirus. It was some way into a multi-hour livestream, so I'm
| not going to try and dig it out though.
| herf wrote:
| For anyone who's interested, CIE recently made their UVGI
| standards available for free ($150 normally):
|
| http://files.cie.co.at/cie187-2010%20(free%20copy%20March%20...
| http://files.cie.co.at/cie155-2003%20(free%20copy%20March%20...
|
| Generally you don't want to be around most UVC (253nm) because
| these wavelengths are very good at giving you cataracts, etc. So
| if you buy these things online, don't stay in the room when you
| turn them on.
|
| There are some newer lamps (210-220nm) that don't seem to
| penetrate the outer layer of the epidermis (cornea or skin) and
| so might be OK for occupied spaces. But companies are still being
| very cautious about occupied uses, because this all still has yet
| to be proven in real life. Also, 220nm requires excimer lamps, so
| 253nm is way easier to get for now.
| prox wrote:
| How about just heating your mail in a dry oven? Thats what
| Stanford tested for PPE masks.
|
| Or just waiting 24 hours or more works as well,
| wideasleep1 wrote:
| Just to add, when I did some research on excimer lamps last
| week, producers are few, and the research I discovered were
| sometimes using the 253nm lamps, but adding filters to get to
| the 210-220nm range. It quite confusing, to say the least.
|
| Edit: Indeed the article linked above is one such study:"We
| used a bank of three excimer lamps containing a Kr-Cl gas
| mixture that predominantly emits at 222 nm25,26. The exit
| window of each lamp was covered with a custom bandpass filter
| designed to remove all but the dominant emission wavelength as
| previously described15. Each bandpass filter (Omega Optical,
| Brattleboro, VT) had a center wavelength of 222 nm and a full
| width at half maximum (FWHM) of 25 nm and enables >20%
| transmission at 222 nm."
| sakoht wrote:
| It's sad that even the BBC allows people who don't know what they
| are talking about to spread propaganda, not even knowing it. It
| kills everything the size of a virus because of its size, not
| some magical attributes the virus may or may not have. The other
| comments show three recent scientific publications in top-tier
| journals showing the narrow wavelength (222nm) that doesn't harm
| human skin or eyes.
| whatshisface wrote:
| > _It kills everything the size of a virus because of its size,
| not some magical attributes the virus may or may not have._
|
| It wouldn't cause a tiny iron sphere to disintegrate. It's not
| true that everything the size of a coronavirus can be "messed
| up" by UV light.
| Confiks wrote:
| Has anyone found anything on the health implications of mounting
| 220nm lamps [1] indoors, _beyond_ the issue of damaging human
| DNA? In other words, if you assume those lamps to be safe to
| living cells due to the light not penetrating beyond the first
| layer of dead skin cells, what other problems might there be?
|
| Our skin surface contains a lot of living bacteria. Different
| strains seem compete with each other, and for example an
| overgrowth of staphylococcus aureus seems to be correlated with
| skin issues. In that sense living bacteria protect our skin. How
| would an far-UVC 'antibiotic' lamp influence bacterial
| repopulation later? Either on skin and in spaces. Would it impair
| immune system development?
|
| Viruses seem far more fragile than bacteria, so perhaps a low-
| power far UVC-lamp will be enough to kill viruses but leave the
| bacterial populations on skin and objects intact
|
| [1] https://www.nature.com/articles/s41598-018-21058-w
| fabian2k wrote:
| You get a nasty sunburn from resonably strong UV lamps. I've
| seen that happen with people being very careless in the lab
| when using a UV bed for gel electrophoresis.
|
| These are UV lamps strong enough to visualize ethidium bromide,
| I'm not even sure if they're strong enough to kill bacteria
| quickly, though I'd guess they might be. UV lamps are really
| not something you should point at humans.
| RL_Quine wrote:
| It also burns your retinas and produces ozone.
| CamperBob2 wrote:
| No optical damage in this wavelength range (although the
| ozone may still be an issue.)
|
| Suggest reading the articles people have linked to in this
| thread, pretty interesting stuff. I had no idea that there
| was a portion of the UVC spectrum that doesn't have
| significant harmful effects on humans.
| daenz wrote:
| >In short: no.
|
| https://en.wikipedia.org/wiki/Betteridge%27s_law_of_headline...
| [deleted]
| dougmwne wrote:
| Please do not spread disinformation. Your statement contradicts
| the article. This is a time when we need to be very careful
| about what we are sharing on social media. The article explains
| that artificially produced UVC is effective against other
| chronaviruses, but that studies on COVID-19 specifically and
| sunlight generally are lacking.
| vultour wrote:
| That is literally a quote from the article.
| NullPrefix wrote:
| >Your statement contradicts the article
|
| The article itself contradicts the article
| [deleted]
| m-p-3 wrote:
| But UVC has been shown to be effective against SARS[1], so
| there is a good chance COVID-19 would also be affected.
|
| [1]:
| https://www.sciencedirect.com/science/article/pii/S016609340...
|
| > The virus was inactivated by ultraviolet light (UV) at 254 nm
|
| > At 3 cm our UVC light source (254 nm) emitted 4016 mW/cm2
| (where mW = 10-6 J/s) and the UVA light source (365 nm) emitted
| 2133 mW/cm2, as measured by radiometric analysis (Spectronics
| Corporation). After exposure to the UV light source, virus was
| frozen for later analysis by TCID50 assay using CPE as the
| endpoint.
|
| > Exposure of virus to UVC light resulted in partial
| inactivation at 1 min with increasing efficiency up to 6 min
| (Fig. 1A), resulting in a 400-fold decrease in infectious
| virus. No additional inactivation was observed from 6 to 10
| min. After 15 min the virus was completely inactivated to the
| limit of detection of the assay, which is <=1.0 TCID50 (log10)
| per ml. In contrast, UVA exposure demonstrated no significant
| effects on virus inactivation over a 15 min period. Our data
| show that UVC light inactivated the SARS virus at a distance of
| 3 cm for 15 min.
|
| So UVC would be indeed effective by these metrics.
|
| I kinda hope we can build something similar to disinfect
| laptops and cellphones at work, there are so many people
| touching those and taking the habit of flooding them with UVC
| before working on them or giving them back to a user would be a
| good step to reduce transmission.
| IgorPartola wrote:
| Just an anecdote but in college I had a chemistry professor
| who had the absolute filthiest keyboard I have ever seen. It
| was famous throughout the university because it easily had
| 1.5mm of grime on every single key. I asked him about it once
| (I assume others did too) and he said that every year the
| first year biology students swab his keyboard to grow
| bacteria in Petri dishes as a part of their curriculum. While
| those Petri dishes with swabs from other place grow like
| crazy, nothing ever grows from his keyboard.
| smileysteve wrote:
| This is a pretty sham conclusion. "No" if you use where people
| are. No mention of the utility in cleaning areas that are
| temporarily closed to the public.
|
| Light hits a lot more surface than just you are spraying and
| wiping.
|
| In things like grocery stores being cleaned every night; or even
| with modern proximity sensors being able to turn on a 5 min burst
| of uv-c without anybody in the room. Uv-c (while yes requiring
| precautions) should work great.
|
| I happened to have bought a uvc wand in November. It has a button
| and tilt sensor so it's hard to accidentally scan over your eyes.
| It's definitely reassuring to "wipe" the phone and door handles
| when I come back in the house at close proximity for a few
| seconds.
| perl4ever wrote:
| I'm not running out to get any sort of UV lamp now but I am
| mildly interested in a thing I heard about that works with forced
| air ducting in a home AC/heating system. Not sure if it would
| help with allergies.
| LifeLiverTransp wrote:
| You can even disinfect breathing air, if you have a reflective
| pipe that is long enough.. and a uv source.
| tiku wrote:
| Time for led bulbs that also contain uvc light, perhaps with a
| battery so that you can clean a room after you turn of the light.
| blackhaz wrote:
| I have ordered a 15 W Chinese E27 UVC (200-275 nm) lamp from
| Amazon, and a E27 to wall socket plug with remote control. I am
| going to place it in the quarantine zone downstairs to zap
| incoming mail and packages, just for any case.
|
| In one SARS-CoV study [1] the authors have irradiated SARS-CoV
| with a 254 and 365 nm UVC-UVA light source that emitted 4016
| mW/cm^2. They found that "exposure of virus to UVC light resulted
| in partial inactivation at 1 min with increasing efficiency up to
| 6 min (Fig. 1A), resulting in a 400-fold decrease in infectious
| virus."
|
| If my math is correct, a 15 Watt UVC light bulb will provide 4.77
| W/m^2 flux within the radius of 0.5 m - assuming it emits
| omnidirectionally. Assuming the delivered power versus
| inactivation efficiency relationship is linear, it would require
| roughly about an hour of zapping to achieve the same levels of
| inactivation with a 15 W lamp.
|
| Yes, we don't know if SARS-CoV inactivation times are comparable
| to that of COVID-19, but it's better than nothing. I am not a
| biologist, and micrographs of both viruses look somewhat similar.
| I wonder if they are structurally similar, should we expect
| similar susceptibility to incoming UV photons?
|
| [1] https://medtradex.com/assets/Uploads/Literature-UVD-
| Corona.p...
| lvturner wrote:
| Would you mind linking to the light you bought? Or a comparable
| one l.
| blackhaz wrote:
| Here is the one. I don't know if it performs in spec. Never
| bought one before.
|
| https://www.amazon.co.uk/gp/product/B085HZK755/ref=ppx_yo_dt.
| ..
| jennyyang wrote:
| I bought a cheap glass aquarium for my UVC light bulb.
| Glass block UVC light completely so it becomes safe to use
| that for smaller items. Also you will produce a lot of
| ozone, so do this outdoors with a lot of ventilation.
| walterbell wrote:
| Because this is (a) NOT Far-UVC, and (b) 360-degree light
| that shines in all directions, the only way to use it
| safely is with a remote power switch or a short timer so
| you (and pets) can get out of the room before the light
| turns on. Don't re-enter the room until the light is
| switched off remotely or with a timer. It is hazardous to
| your eyes and skin.
|
| Could it be used in a spotlight lamp that directs all the
| light in one direction?
| jennyyang wrote:
| I mention below I place the light bulb (using a hand-held
| socket) in a glass aquarium. Glass completely blocks UV-C
| light. The other hazard is ozone, so I use this outdoors
| on my patio or garage.
| nerfhammer wrote:
| > Glass completely blocks UV-C light.
|
| Erm, then why do they come in glass tubes like florescent
| lights?
| blackhaz wrote:
| Yeah, I got a E27 socket wall plug with wireless control.
| I assume it should be possible to get a remotely
| controlled lamp with reflector to make a spotlight out of
| it.
| bikenaga wrote:
| This is a 3-watt handheld - the power may be too low.
|
| https://www.amazon.com/Foldable-Travel-Household-Wardrobe-
| To...
| jennyyang wrote:
| One thing to note is that in your calculations, you are using
| 50cm distance, but in the study you linked, they are using 3 cm
| distance. Since this is inverse square law, that makes sense it
| would take longer to deactivate.
|
| For another point of reference, this study[1] says it takes 1.8
| J/cm^2 to deactivate the flu virus. I'm not sure which is more
| hearty but from my calculations, it seems as though it's
| similar (about 2 J/cm^2). If that's the case then if you
| brought the intensity of your light up (bring the bulb much
| closer and possibly wrap it in material that reflects UV-C if
| that's even possible) then it would only take seconds to
| deactivate the virus.
|
| [1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4699414/
| blackhaz wrote:
| As far as I understand, we are talking about flux - per area
| at specified distance, not luminosity. I did recalculate flux
| for 0.5 m.
| jennyyang wrote:
| No. The study I referenced used total energy per cm^2
| required to deactivate the flu virus, which is J/cm^2. You
| get that by multiplying the flux by the exposure time.
|
| So whichever exposure time gets you the 1.8 J/cm^2 is
| enough to kill the flu virus and presumably SARS-CoV-2.
| dillonmckay wrote:
| Make sure you wear longsleeve clothes and sunglasses, so you do
| not burn your skin or eyes!
| sjg007 wrote:
| Yeah I would expect a rise in HVAC installations. I was surprised
| that cruise ships don't have them installed along with hepa
| filters.
| wool_gather wrote:
| Interesting; is this a current practice? How do you get enough
| exposure time to be effective in moving air?
| mensetmanusman wrote:
| By integrating over distance :)
| outlace wrote:
| Is it the seasonal changes in UV that make flu and similar
| viruses less transmissible during the summer months? Maybe it has
| nothing to do with temperature as some have suggested.
| chrisco255 wrote:
| It's been argued that both temperature and humidity make
| viruses less transmissible. Not sure about the UV intensity.
| Giorgi wrote:
| So article says: "No" and then goes on to describe how it kills
| virus. WTF
| downerending wrote:
| Crappy headlines are a major form of fake news.
|
| (I wrote to a major paper once to complain about this, and the
| author of the article replied: _Well, I don 't write the
| headlines._ Hooray.)
| a3n wrote:
| I wrote to the Denver Post once, and the editor replied "We
| don't write the articles." It was a local story, but written
| by the paper's owning entity, for publication in all of its
| owned papers, including the Post where the incident happened.
| I guess sort of like an in-house news wire "service."
|
| They do obviously write some of the articles that appear in
| their paper.
| [deleted]
| ebg13 wrote:
| Yes AND, despite the mongering in this article, UVC wavelengths
| below 222nm have been found to be safe to mammalian skin.
|
| https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5552051/
|
| https://journals.plos.org/plosone/article?id=10.1371/journal...
| modeless wrote:
| Wow, that's surprising, and exciting. If true, every room in a
| hospital should have these lights.
| 77pt77 wrote:
| Let's start with copper doorhandles and bed-frames.
|
| Far better tested and understood.
| dijit wrote:
| It still takes 4hrs for copper to kill coronavirus. Why not
| both?
| dogma1138 wrote:
| One of those is known not to cause long term adverse
| effects.
| m-p-3 wrote:
| Interesting, thanks for sharing.
| jiofih wrote:
| From the linked paper:
|
| > the effect of chronic irradiation with a high dose of 222-nm
| UVC to mammalian cells has not been determined
|
| Please be careful in announcing new truths based on your
| interpretation of a couple papers. That's not how science is
| done.
| boomboomsubban wrote:
| The tests on the SARS virus used 254nm wavelengths, which
| deactivated the virus in fifteen minutes. Your sources both say
| that that length causes severe damage, and both only tested
| 222nm's ability to kill bacteria. A conclusive "yes" would need
| testing done on a virus with the 222nm length.
| jennyyang wrote:
| Not only skin, but also eyes. You can look at Far-UVC light and
| it won't hurt your eyes either. Whereas regular UVC light can
| burn your eyes and cause temporary or permanent blindness.
| [deleted]
| mrfusion wrote:
| I've always wondered. Why can't we put uv lamps in Hvac air
| handlers? Especially on airplanes and cruise ships.
|
| I guess before there was no compelling reason to have the extra
| cost but now it might be time to rethink it.
| rini17 wrote:
| UVC lamps produce ozone which is not healthy to breathe.
| techsupporter wrote:
| We can. Half a lifetime ago, I replaced the HVAC in my house
| and one of the add-ons, which I bought, was a UV disinfecting
| lamp.
|
| I have no idea if it was effective or snake oil but it was on
| offer. Hospitals and medical labs have (demonstrably effective)
| UV lights in their HVAC systems.
| tzs wrote:
| Slightly OT: numerous sources say that if the virus is on a
| surface, it eventually dies (or deactivates anyway, if you don't
| consider viruses alive in the first place). It can last up to 4
| days on glass, 3 on steel and plastic, and 24 hours on cardboard.
|
| What I've not seen explained and have no guess for is _why_ it
| deactivates. It doesn 't have a metabolism. It doesn't consume
| resources or use energy. It just sits there, a little spiky
| spheroid surrounding some fragments of DNA or RNA.
|
| So what changes about it as it sits that causes it to deactivate?
| saiya-jin wrote:
| Just guessing - molecules of oxygen flying like crazy all
| around (somewhere read on average 5km/s), eventually at one
| point knocking something crucial off?
|
| At those scales, these things start to matter.
| MikeAmelung wrote:
| Just taking a shot in the dark here, but it likely just
| disintegrates, probably from moisture and even friction from
| air. That would explain why the "survival" is inverse to the
| moisture-holding capability of the surface.
| lisper wrote:
| Entropy. A virus is simple by the standards of living things,
| but it's still a pretty complicated system. There are lots of
| random perturbations that can affect it ranging from quantum to
| cosmic rays to chemical and thermal perturbations. All it takes
| to deactivate a virus is to break one of its many critical
| chemical bonds so that it can no longer reproduce.
|
| [UPDATE] Wow, five replies posted within two minutes of each
| other! As other parallel replies have pointed out, oxygen is
| very likely a significant factor here as it is plentiful and
| very reactive.
| ceejayoz wrote:
| They dry out.
|
| https://www.usatoday.com/in-depth/news/2020/03/25/coronaviru...
|
| > In all settings, viruses need water to survive. "Viruses can
| withstand a small amount of dehydration," says Dr. Paul
| Meechan, a former director of safety at the Centers for Disease
| Control and Prevention and president of the American Biological
| Safety Association.
| ChuckMcM wrote:
| I believe this is the correct answer. My daughter with the
| masters in biology also said this was the answer.
|
| Interesting side effect is that you can deactivate the virus
| by putting it in a warm dry atmosphere. The warmth encourages
| evaporation and drying.
|
| Sadly I don't have any equipment for doing viral particle
| counts (was tempted to bid on some here:
| https://www.equipnet.com/auctions/ but alas, I already have
| way more EE test gear than I can use, no sense adding a full
| bio laboratory to the mix :-).
|
| Even though I cannot prove its viability as a mitigation
| solution, since I have a heat gun I spray my mail with 610
| degree F heat to ensure it is dry and warm (without exceeding
| 452 degrees of course!)
| [deleted]
| wirrbel wrote:
| the corona virus (similar to the HI virus) has an envelope
| which is a lipid bilayer, there are viruses without an
| envelope. Now you may think that a virus with an envelope is
| more stable than viruses without, but the contrary is the case.
| once the bilayer tears, the virus is dysfunctional.
|
| Also, what is not always talked about in the media currently
| is, that not all viruses are replicated functional. In fact, a
| large fraction of viruses produced are not capable of infecting
| a cell in the first place due to replication errors, mutations,
| etc.
| whatshisface wrote:
| > _what is not always talked about in the media currently is,
| that not all viruses are replicated functional. In fact, a
| large fraction of viruses produced are not capable of
| infecting a cell in the first place due to replication
| errors, mutations, etc._
|
| I agree that people aren't writing news articles about that,
| but why is it noteworthy that they're not? It doesn't matter
| if only 1% of the virus particles on a surface are infectious
| if there are millions of particles.
| [deleted]
| clumsysmurf wrote:
| "SARS-CoV-2 RNA was identified on a variety of surfaces in
| cabins of both symptomatic and asymptomatic infected passengers
| up to 17 days after cabins were vacated on the Diamond Princess
| but before disinfection procedures had been conducted"
|
| https://www.cdc.gov/mmwr/volumes/69/wr/mm6912e3.htm?s_cid=mm...
| ceejayoz wrote:
| RNA !== active virus.
|
| "Saying that live virus is there because viral RNA was found
| is like saying I must be holding a meatball sub because
| there's a marinara stain on my pants." -
| https://twitter.com/kenjilopezalt/status/1242285123652825089
| tejtm wrote:
| They disassemble, the atoms find lower energy states.
| esahione wrote:
| Oxygen and the atmosphere.
| guardiangod wrote:
| https://www.marketwatch.com/story/deadly-viruses-are-no-matc...
|
| _So why are surfaces different? The virus is held together by
| a combination of hydrogen bonds (like those in water) and
| hydrophilic, or "fat-like," interactions. The surface of fibers
| or wood, for instance, can form a lot of hydrogen bonds with
| the virus.
|
| In contrast, steel, porcelain or Teflon do not form much of a
| hydrogen bond with the virus. So the virus is not strongly
| bound to those surfaces and is quite stable._
| devy wrote:
| The simple answer is it probably can, but the actual facts are
| more nuanced than a simple confirmation.
|
| All bio-safety labs or hospitals or water treatment plants or
| special HVAC systems have UV-C lamps to sanitize pathogens
| because UV-C radiation destroying nucleic acids (DNAs / RNAs).[1]
| However, the effectiveness really depends on the amount
| exposure/energy level, light of sight(because UV-C doesn't
| penetrate deep into objects), and even dust in the air or the on
| the UV-C light lamps(which reduced the energy they emit) as well
| as how DNA/RNA can be evolved or self-repaired.
|
| Anecdotally, Chinese hospitals are using UV-C lamp to sanitize
| their medical equipments, masks (when it was in short supply
| months ago) among other things.
|
| And yes, more exhaustive experiments should be conducted to
| affirm this practice as it's the most non-toxic and energy
| efficient way to sanitize surfaces.
|
| [1]:
| https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradia...
|
| [2]: https://www.cnbc.com/2020/03/18/how-china-is-using-robots-
| an...
| dillonmckay wrote:
| All water treatment plants do not use UV.
|
| It is actually fairly expensive.
|
| Some municipalities only use chlorine. My municipality only has
| a 40 day supply of chlorine to treat the water.
|
| For such reasons, I purchased a whole-home UV-C water unit.
|
| Now, the wastewater plant uses UV-C, but its output is cleaner
| than the drinking water input (river).
| Scoundreller wrote:
| Can also use ozone. One of Toronto's plants uses it and
| treats about 20% of the city's water. Nice thing is that you
| don't need railcars to arrive with it.
|
| https://www.toronto.ca/services-payments/water-
| environment/t...
| taborj wrote:
| > I purchased a whole-home UV-C water unit.
|
| Got a link for the system you use?
| makomk wrote:
| It's not just Chinese hospitals that are using UVC to sterilize
| masks, I think some US hospitals have started doing the same
| thing due to the shortage there.
| greedo wrote:
| This is being pioneered in Omaha:
|
| https://www.unmc.edu/news.cfm?match=25283
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(page generated 2020-03-28 23:01 UTC)