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Germicidal UV could make airborne diseases as rare as those carried by water

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Re: Germicidal UV could make airborne diseases as rare as those carried by water

#41

Post by rocqua »

bondarchuk wrote: post #32
mriet wrote: post #23

Idiotic and massively overlooks/underestimates how complex biology is. What about beneficial and neutral but important bacteria and viruses? "Air" is actually a complex soup of all types of things. This like applying HCl to a skin infection.

I doubt it would be a problem for the microbiome [1] but I would worry about the immune system. Would being inside in sterilized air all the time mean you can't go outside or into a forest without getting really sick? [1] but who am I, it would still be worthwhile to check obviously

The underlying thought is that outside air (such as a forest) gets UV sterilized by the sun. So this would bring inside air up to the sterilization level of outside air.

Re: Germicidal UV could make airborne diseases as rare as those carried by water

#42

Post by metalman »

mahrain wrote: post #6

I have worked on such systems at Signify: There are numerous barriers to wider adoption except for very high risk situations. For instance: there have yet to be lawsuits to determine the risk of exposing people to UV. As you see in the comments below, any "UV" is considered dangerous by people not aware of the biological effects of various wavelenghts. Besides this, excimer lamps have a low expected lifetime, of both…

there are much simpler and more reliable ways to significantly reduce indoor air contaminents. one is a building method that produces a "floating" slab floor, that has a small gap around most of the walls, and the underfloor space is vented upwards with a chimney, this creates a small but continious air current that removes most dust and other things in the air.

And then the simple expedient of useing radiant heat sources, that while not as lethal as UV, are in fact quite deadly to bacteria and anything tiny with a high water content, but completly harmless to humans and ,animals,plants. Couple this with hard, smooth ,surfaces that are designed so that there no crevices or areas filth can acumulate, useing hard woods,glass,tile,metal,leather/vinyl l,high gloss paint,for surfaces. No cloth, no carpet.While not exactly cosy or friendly, it makes getting home that much nicer. Cheap, reliable, low maintenence, implimentable at scale, now.

Re: Germicidal UV could make airborne diseases as rare as those carried by water

#43

Post by bschwarz »

pazimzadeh wrote: post #39
more_corn wrote: post #2

UV causes melanoma which is why we wear sunscreen.

too much UV all at once, you mean. melanoma is not common and face and arms - the regions which receive the most sunlight a moderate amount of UV stimulates vitamin D production, suppresses inflammation, and turns on DNA repair pathways

This moderate amount of UV is enough to accelerate skin aging which is why we wear sunscreen.

Re: Germicidal UV could make airborne diseases as rare as those carried by water

#44

Post by jiehong »

mahrain wrote: post #22
ur-whale wrote: post #18

Wont micro-organisms quickly adapt and start producing UV resistant strains?

The germicidal effect is a function of the DNA being directly affected by the UV rays and breaking apart. Very few organisms exist that could adapt, this would require external shells, skin etc, not typically found in microorganisms.

Tardigrades and organisms ables to survive space by having more efficient DNA repair mechanisms.

Unlikely for most organism, true

Re: Germicidal UV could make airborne diseases as rare as those carried by water

#45

Post by mahrain »

metalman wrote: post #42
mahrain wrote: post #6

I have worked on such systems at Signify: There are numerous barriers to wider adoption except for very high risk situations. For instance: there have yet to be lawsuits to determine the risk of exposing people to UV. As you see in the comments below, any "UV" is considered dangerous by people not aware of the biological effects of various wavelenghts. Besides this, excimer lamps have a low expected lifetime, of both…

there are much simpler and more reliable ways to significantly reduce indoor air contaminents. one is a building method that produces a "floating" slab floor, that has a small gap around most of the walls, and the underfloor space is vented upwards with a chimney, this creates a small but continious air current that removes most dust and other things in the air. And then the simple expedient of useing radiant heat so…

Your first paragraph is advocating for ventilation, which is great but there's been so much incentive to reduce building energy consumption (heating/cooling) that recirculating, filtration and other technologies have resulted in offices becoming almost sealed off. We are now moving towards more balanced models as people don't feel comfortable in such offices e.g. sick building syndrome.

Re: Germicidal UV could make airborne diseases as rare as those carried by water

#46

Post by scns »

vintermann wrote: post #17

No mention of ozone. The more directly dangerous 254nm UV light has the advantage that it doesn't create ozone. Viruses and bacteria aren't the only bad things you don't want in your air. Ozone is thought to be a carcinogen in its own right and aggravate the health effects of particulate pollution. We want filtering and air circulation anyway, we don't want anything that makes it worse. The consumer electronics indus…

> things that make our problems worse, such as ultrasonic humidifiers, or ionizing air purifiers

What is bad about these?

Re: Germicidal UV could make airborne diseases as rare as those carried by water

#47

Post by harddrivereque »

rob74 wrote: post #30
Llamamoe wrote: post #28

Earlier quoted context omitted.

Is there any reason why they can't just be installed inside air purifiers/ventilation? Especially since you could probably get more mileage out of the same amount of light energy by forcing the air through a narrower passage, since only airborne particles are actually going to absorb any energy anyway, and air is mostly just empty air.

That solution is actually suggested in the article. However, that still leaves the cost issue mentioned by GP, and until that is solved, this will remain something for specialized applications (operating rooms) and maybe hypochondriac millionaires...

...and maybe diy germaphobes.. just like positive air pressure ventilation systems. In fact, you could combine

Re: Germicidal UV could make airborne diseases as rare as those carried by water

#48

Post by stuaxo »

unsnap_biceps wrote: post #10
mahrain wrote: post #6

I have worked on such systems at Signify: There are numerous barriers to wider adoption except for very high risk situations. For instance: there have yet to be lawsuits to determine the risk of exposing people to UV. As you see in the comments below, any "UV" is considered dangerous by people not aware of the biological effects of various wavelenghts. Besides this, excimer lamps have a low expected lifetime, of both…

Every year our HVAC company tries to sell us UV lights for the HVAC system. They claim it's only about $1500 to install. Are these snake oil?

If I had an HVAC system I would absolutely have UV in it, to mitigate sick building syndrome etc.

Can't comment on the price.

Re: Germicidal UV could make airborne diseases as rare as those carried by water

#49

Post by Lapra »

mriet wrote: post #23

Idiotic and massively overlooks/underestimates how complex biology is. What about beneficial and neutral but important bacteria and viruses? "Air" is actually a complex soup of all types of things. This like applying HCl to a skin infection.

I recently read the book "Invisible Friends," and in it, among other things, the author does go on to explain that it's theorised that many skin infections come from a lack of biodiversity in a persons' skin microbiome, because the "good" or neutral microbes compete with the "bad" for resources. Supposedly people who share a house together often have similar gut microbiomes, too.

So yeah, I don't know. I think you have a point here.

Re: Germicidal UV could make airborne diseases as rare as those carried by water

#50

Post by DennisP »

rob74 wrote: post #30
Llamamoe wrote: post #28

Earlier quoted context omitted.

Is there any reason why they can't just be installed inside air purifiers/ventilation? Especially since you could probably get more mileage out of the same amount of light energy by forcing the air through a narrower passage, since only airborne particles are actually going to absorb any energy anyway, and air is mostly just empty air.

That solution is actually suggested in the article. However, that still leaves the cost issue mentioned by GP, and until that is solved, this will remain something for specialized applications (operating rooms) and maybe hypochondriac millionaires...

From a quick search, they are not millionaire-level expensive. Here for example is a 20W 222nm lamp that costs $436, with a lifetime of several thousand hours.

https://uv-can.com/products/gerani-far-uv-light?srsltid=AfmB...

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