The "Far" UV Light, Optical Safety Concerns

Hello,

Reference and respectful acknowledgement is made to those of you who posted to the Link for which, at least the title, is political.

Caveat: This query, here, is intended to be medical only without regard to whether or not any US politicians or political news reporters like or hate the concept.

Reference is made to Far-UVC light: A new tool to control the spread of airborne-mediated microbial diseases

Various websites claim that the 222nm UV light frequency is harmless to the retina.
And, of course they would claim that, in order to support the technology.
This is why I'm taking the question here, to you,
the scholars and subject matter experts of ATS.

I have a hand held wand, for sterilizing objects, that came with strong
warnings to avoid staring into it or staring into any reflection of it.
I wear appropriate protective goggles or just close my eyes
when using it to disinfect things.
This wand is surely a different wavelength than new 222nm models.

And so the question becomes, "Is the 222nm "Far" technology really safe to stare at?

I have to be skeptical of the manufacturers' safety claims, and that's why I'm
here, to defer to you guys for the real answers.

Thank you very very much.

a reply to: Adonsa

i dunno - is the simple answer . i has only actually messed with stuff at the IR band for heating and night vision optics
- and obviously had a good idea what protection , magnitude and duration is safe - and what protection is needed

but the claim [ for UV ] is utterly counter intuative
many valid science principles are counter intuative too

but this seems too ad hoc

an explaination :

he visible spectrum [ 400nm ~ 650 nm = GRAS [ subject to insensity and duration ]

UV light - various [ 300nm ] = hazardous - exposure must be limited

" magic UV light" @ 220nm = magically safe - whoo hoo

x-rays - at lower spectrum bands = hazardours - this crap kills you @ high does // duration

yes - medical x-rays are used on humans - but the power and duration are minuite

this munkie is skeptical - and would recommend testing the claim on people who claim its safe

I said in a post about this that it WILL hurt the eye.
just 1 seconds will leave a little scaring in the back of the eye.
about a hour later you will get a feeling like grit in the eye.
that is the scaring. dont bother rubing it or puting drops in the eye.
it is inside the eye. it will heal in about 4 hours. or less.

So Dont look directly at the UV light.
it is NOT the same as a Disco UV light.
they are safe.

I doubt if it would be good for anyone if they were in that light for a longer period of time. It would be all right to use a wand, as long as it is not shining in your eyes for long periods of time. The light is good for sterilizing stuff, but remember, our skin is loaded with beneficial bacteria, they are not all bad. We live symbiotically with certain bacteria.

If we start living in a sterile environment it will be bad for us, there are viruses and bacteria all over the place. If it is too sterile, we wind up overreacting when we are exposed to anything or we wind up with an inferior innate immune response to actual pathogenic microbes.

I would not want to have those lights on all day long, but would not feel using a wand in a grocery store while working would be something I would worry about. To me, the cleaning chemicals they use would be probably worse than the UV light.

a reply to: Adonsa

According to some of the studies referenced in the Nature article, on human cells specifically:

Link to graphs

Link to part II

Germicidal Efficacy and Mammalian Skin Safety of 222-nm UV Light

"Completely harmless" might be strong wording. It seems some areas, such as parts of the mouth, can still be penetrated by that part of the UV spectrum.

However, it does seem significantly, significantly less harmful to human tissue than typical disinfecting wavelengths like 254nm.

As rickymouse stated, however, "germs" and viruses and general bacteria are actually beneficial to us in many ways. This perspective of "eradicate them all!" might just end up being more harmful than if we had just left well enough alone.. regardless of if the wavelengths harm human tissue or not.

originally posted by: Adonsa
Hello,

Reference and respectful acknowledgement is made to those of you who posted to the Link for which, at least the title, is political.

Caveat: This query, here, is intended to be medical only without regard to whether or not any US politicians or political news reporters like or hate the concept.

Reference is made to Far-UVC light: A new tool to control the spread of airborne-mediated microbial diseases

Various websites claim that the 222nm UV light frequency is harmless to the retina.
And, of course they would claim that, in order to support the technology.
This is why I'm taking the question here, to you,
the scholars and subject matter experts of ATS.

I have a hand held wand, for sterilizing objects, that came with strong
warnings to avoid staring into it or staring into any reflection of it.
I wear appropriate protective goggles or just close my eyes
when using it to disinfect things.
This wand is surely a different wavelength than new 222nm models.

And so the question becomes, "Is the 222nm "Far" technology really safe to stare at?

I have to be skeptical of the manufacturers' safety claims, and that's why I'm
here, to defer to you guys for the real answers.

Thank you very very much.

The answer to your question depends on how you want to define the word "safe".

The first thing to understand is that all organisms--from humans down to fungi, bacteria, and viruses are constructed predominantly of organic molecules. Those are mainly combinations of Hydrogen, Oxygen, Carbon, and Nitrogen atoms. Organic molecules are relatively easy to cut apart with light energy, compared to other compounds such as minerals, metals, glasses, etc. The process of cutting molecules apart with light is called "photolysis". All UVC frequencies are capable of photolysis of organic molecules. That is why they are considered germicidal, they cut apart the molecules from which germs are constructed and render them noninfectious. UVC will also cut apart the molecules from which humans are made.

The claim by the people who sell 222 nm UV sterilizers is that that particular wavelength is essentially all absorbed in the first layers of organic material it encounters and therefore never makes it deeper than about 10 microns. Let's assume that they are 100% correct in that statement. What that means is that it cannot get down below the outer layer of skin, which contains no genetic material. That means it can't begin the process of mutagenesis, which ends up as skin cancer. It also probably means that it can't get through to your retina to damage the cells there.

However, by definition, if all the UV is being absorbed within the first 10 microns of whatever tissue it comes in contact with, all the damage will be done there. So the outer layer of your skin would become less flexible and more leathery, and your corneas would still accumulate damage that could lead to cataracts.

But you wouldn't get cancer, unless you shined it inside your body, where you don't have a protective layer of epidermis.

I dunno. I used to have sun staring contests with friends as a kid. Wouldn't recommend it. I wear coke bottles now.

Price of winning I guess.

All ranges of light whether visibe or not can cause damage. So, I think it's best to avoid prolonged exposure.

Temporary exposure may cause damage as well, but probably not to the extent of total loss of vision. May end up needing some form of corrective vision.

originally posted by: buddha
I said in a post about this that it WILL hurt the eye.
just 1 seconds will leave a little scaring in the back of the eye.
about a hour later you will get a feeling like grit in the eye.
that is the scaring. dont bother rubing it or puting drops in the eye.
it is inside the eye. it will heal in about 4 hours. or less.

So Dont look directly at the UV light.
it is NOT the same as a Disco UV light.
they are safe.

You are right, or at least near right.

I had my right eye, (just in the right eye) some rods damaged in an area near the top of vision to the right, while not in the main area of focus thankfully, by a car waiting to turn left at a junction on my right. I just happened to glance, without turning my head so much, at that car which had a ridiculously lowered suspension, an older model VW Jetta, or Passat...popular here for youngsters who mess, and got a serious flash of very strong blue to the white light, much stronger than xenon, and it did hurt noticeably.
It left me with a grey 'fog' effect exactly like a glaucoma sufferer might have, however that effect has not gone away, the rods, or rather some of them are permanently damaged.

I still have 20/20 corrected vision thankfully, as the damage is not in the main point of focus, but the grey crescent shaped, 'fog' (the shape of the lamp?) remains.

originally posted by: rickymouse
I doubt if it would be good for anyone if they were in that light for a longer period of time. It would be all right to use a wand, as long as it is not shining in your eyes for long periods of time. The light is good for sterilizing stuff, but remember, our skin is loaded with beneficial bacteria, they are not all bad. We live symbiotically with certain bacteria.

If we start living in a sterile environment it will be bad for us, there are viruses and bacteria all over the place. If it is too sterile, we wind up overreacting when we are exposed to anything or we wind up with an inferior innate immune response to actual pathogenic microbes.

I would not want to have those lights on all day long, but would not feel using a wand in a grocery store while working would be something I would worry about. To me, the cleaning chemicals they use would be probably worse than the UV light.

I find it very odd that they say colloidal silver kills bad bacteria.
some people take a Lot of it. but it does not seem to harm them?
the human bodie is about 70% or more bacteria!
we sun bath and use sun lamps to tan the skin.
we take antibacterial drugs.
should all this kill the 70% bacteria kill us or make us sick?
but Nothing? verry odd.

originally posted by: smurfy

originally posted by: buddha
I said in a post about this that it WILL hurt the eye.
just 1 seconds will leave a little scaring in the back of the eye.
about a hour later you will get a feeling like grit in the eye.
that is the scaring. dont bother rubing it or puting drops in the eye.
it is inside the eye. it will heal in about 4 hours. or less.

So Dont look directly at the UV light.
it is NOT the same as a Disco UV light.
they are safe.

You are right, or at least near right.

I had my right eye, (just in the right eye) some rods damaged in an area near the top of vision to the right, while not in the main area of focus thankfully, by a car waiting to turn left at a junction on my right. I just happened to glance, without turning my head so much, at that car which had a ridiculously lowered suspension, an older model VW Jetta, or Passat...popular here for youngsters who mess, and got a serious flash of very strong blue to the white light, much stronger than xenon, and it did hurt noticeably.
It left me with a grey 'fog' effect exactly like a glaucoma sufferer might have, however that effect has not gone away, the rods, or rather some of them are permanently damaged.

I still have 20/20 corrected vision thankfully, as the damage is not in the main point of focus, but the grey crescent shaped, 'fog' (the shape of the lamp?) remains.

Have you seen a Opticians?
if not have a full eye test.

I have lookt at arc welders (Bad UV)
found out how bad it was the hard way as a kid.
and UV lights, even a UV LOW power laser.
my eyes got beter. only about 1 hour of Bad itching.
so I dont think a brief flash would permanently damage you eyes.

originally posted by: buddha

originally posted by: rickymouse
I doubt if it would be good for anyone if they were in that light for a longer period of time. It would be all right to use a wand, as long as it is not shining in your eyes for long periods of time. The light is good for sterilizing stuff, but remember, our skin is loaded with beneficial bacteria, they are not all bad. We live symbiotically with certain bacteria.

If we start living in a sterile environment it will be bad for us, there are viruses and bacteria all over the place. If it is too sterile, we wind up overreacting when we are exposed to anything or we wind up with an inferior innate immune response to actual pathogenic microbes.

I would not want to have those lights on all day long, but would not feel using a wand in a grocery store while working would be something I would worry about. To me, the cleaning chemicals they use would be probably worse than the UV light.

I find it very odd that they say colloidal silver kills bad bacteria.
some people take a Lot of it. but it does not seem to harm them?
the human bodie is about 70% or more bacteria!
we sun bath and use sun lamps to tan the skin.
we take antibacterial drugs.
should all this kill the 70% bacteria kill us or make us sick?
but Nothing? verry odd.

Part of our immune system utilizes silver. Part utilizes copper. We are of this earth, we need some of these things in our diet or we can even absorb them through our skin from the environment. Too much is not good though. I am much more familiar with the copper enzymes than silver metabolic use. We use silverware, we get a little silver from that in our diet. It was sitting in boxes so we decided it has little value under the bed but the silver plating is useful so we started using it. The little that we absorb from using it every day is not that big, but it is enough when you consider that we get some in our diet like everyone does. I am not going to buy colloidal silver when we get silver in our diet from eating spaghetti with a fork.