E-Mail 'A Primer on UVC Light - Part 2, by Dr. David J.' To A Friend

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13 Comments

  1. Thanks, a very useful article. I need to do a little more research on using UVC to treat filtered rain water. Like the whole house water filter systems, I am sure, there are UVC systems that can be tied in.

  2. UVC lights changes any disease-causing bacteria and virus and fungus — pathogens — to harmless.

    At the risk of pulling a ‘AOC’, how does the wavelength know the difference between health-causing and disease-causing?
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    [For reference, see the meme with the dear child questioning her drinking-mug’s magical ability to keep hot drinks hot and cold drinks cold. In the meme, she wonders “How does it know!”]

    1. A good question, LargeMarge… I will await the opinion of an expert on this, but my best assessment would be that the UVC lights do not differentiate. This is a matter of the greater good or the lesser of the evils.

      1. If I may drop in my scientific understanding; bacteria, mold spores, viruses, pollen, etc etc are essentially draped on everything, everywhere and all the time. We LIVE awash in a sea of “micro life”. Personally, I’m glad I grew up in the country drinking unfiltered well water as I now rarely ever get colds or the flu (so I presume that my immune system got strong facing everyday cooties). One would apply this UV-C technology on those specific surfaces and items that you suspect of contamination, NOT to frequently sterilize your entire world “just in case”. So, I run my keys, phone, every-day-carry stuff thru my UVC box when I get home. Also, I’d expose my bathroom/toilet for 30 minutes if a family member had an upset stomach. And I’d use my portable UVC wand on its internal timer in a hotel bathroom while I went to dinner. You simply can not kill all cooties, nor should you, but you CAN focus on likely problems.

        1. GeoGuy,
          I am with you. UVC kills whatever microbe it encounters, like alcohol and bleach do. Use with discretion, as you would with anything deadly.

          Carry on

  3. Good article on the value of sunlight. Bottom line: get your sorry carcass outside in the sun & fresh air and quit worrying about the comments of the talking heads and so called “experts”, whose opinions change daily. Mostly cause they are on the goobermint payroll and of one sort or another and don’t have a clue how the real world works anyway. Try your best to live by Gods Law and our Constitution…. You live – you die…. That’s just the way it works….

  4. Again many thanks, Dr. David J! There is a lot to learn, and your article has expanded my knowledge base.

    I had a special appreciation for your closing statement: “If you are not sick, then you can be a better asset to your people during the upcoming trials we are all going to face.” I am oft heard using the following expression: “Prevention is the only game in town.” You are right. If we can prevent illness, we should do that — every time — for ourselves, and so that we can support and assist all those around us (being best able to do so when in good health).

  5. Thanks, Dr. J, for this solid overview! I’ll repeat my concern from yesterday that many “Germicidal” LED lamps sold online are bogus. Fortunately, the glass tube lights (low pressure mercury vapor; “LP Hg”) are legit and work as per Dr. J’s guidance above.

    The YouTube channel “bigclivedotcom” has several excellent videos about the bogus LED “germicidal” lights (typically either the fake versions of wands similar to what is described above, or “corn cob” lamps covered in 100-150 LEDs) which only emit nice blue light, but zero UV-C wavelengths. If they have 100+ LEDs but cost only $30-50, they’re almost certainly fake. BigClive suggests using a green banana to test crudely for UV-C; if the skin turns dark after 10-20 minutes of exposure, they DO produce UV light! Note that a true UV-C LED *must* have a tiny metal ring around the LED or they are phony. I have photos of my spectrometer tests of both these real and fake lights, if only I knew how to post them… There ARE real Germicidal LED lamps out there but beware the numerous frauds!

    I have a plastic cooler lined with aluminum foil, a metal rack to hold PPE, cell phone, etc items up off the floor so the light can bounce all around them, a 15W LP Hg bulb in a socket, and a darkroom timer. Furthermore, I have a battery-operated LP Hg “wand” that I use on shopping cart handles, ATM keypads, gas pump controls etc.

    Covid may be mostly transmitted through the air, but sometimes surfaces are a concern too. Use this technology carefully and it works (for Covid or whatever other cooties, including cleaning home when a family member has some bug; as per Dr. J’s description). Best wishes

  6. Thanks to the Doc for his 2 part article on UVC light. Well done and needed.

    I am very familiar with the use of UV light in mechanical applications. It works very well in HVAC systems to aid in limiting bacterial and viral loads. It even helps, although not proven by documentation, with breaking down allergens.

    To address a comment on ozone (O3), O3 is naturally occurring. Every time lightening strikes, O3 is generated. Ever been close to a strike? If you notice, the air smells extremely “clean”. That is O3 cleansing the air. The separation of the third molecule back to O2 is volatile to organic matter, thus will have a detrimental effect. Example. Over 3Kmmg in a 200sf room with a 1 hr constant exposure will ruin natural rubber, kill small bugs and have weird effects on plants. It is a respiratory irritant to humans temporarily, but I’m still here. By the way, O3 has a very short conversion time back to O2, so concentration use and ventilation afterwards is safe.
    In moderation it is an extremely beneficial gas.
    I can personally attest in using it in mold remediation, destruction of organically derived scents (smoke, urine, etc.), and for over a year now, produce extension. I have rechargeable O3 generators in multiple refrigerators and fresh produce lasts way longer. Taste is retained. As long as the product can be exposed to the interior environment, (not in a container) deterioration is inhibited. A word of caution, if you are saving fruit, i.e.. grapes, for homemade wines, it will destroy the natural yeast that would normally ferment the fruit.
    If you do things like that.

  7. I’m sorry but my science/math abilities are limited for an old guy. Is there a simple formula to show how long it takes to cover an “X” amount of area at “X” inches of distance using “X” watt UV light? I have an LED rated at 60W and use it for groceries, package deliveries and my shoes before they come into the house.Got very little info when purchased other than 30min in 500sq ft room for sanitizing.

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