Source: Far-Ultraviolet LED Efficiently Kills Bacteria and Viruses Without Harming People Ultraviolet germicidal lamps are extremely effective at exterminating bacteria and viruses. In fact, they are routinely used in hospitals to sterilize surfaces and medical instruments. Lamps of this type can be constructed with LEDs, making them energy efficient. However, these LEDs produce ultraviolet light in a range that damages DNA and therefore cannot be used around people. The search is on to develop efficient LEDs that shine light within a narrow band of far-ultraviolet light that appears to be both good at disinfecting while remaining safe for people. . . . Who knew the Doctor-President had a clue? Perhaps bleach injections next? Bob Wilson
These have been around for some time; those little UV disinfecters were on the market before COVID . Past models limiting the harmful wave lengths ended up being lower power, which means needing to be closer and longer contact time. These wavelengths still seem to be harmful to plastics and other materials. Your headlights can haze up faster under them. My question is about effective lifespan. The fluorescence types needed to be replaced in 6 months in applications where they ran constantly. Maybe they were good for a year. They still lit up, but they 'dimmed', and were producing less of the effective wavelengths, reaching a point where they weren't killing things.
Ultraviolet light treatment for cancer | Other treatments | Cancer Research UK UV Water Purification - Ultraviolet.com UV Air Purifiers | Honeywell Home How effective is UV-C for industrial hygiene? | ISHN
we had one in our septic system, and i think they use them at the hospital for surgery disinfection. but in both cases, no humans present
I have had uv-c light in my heat pump air handler for twenty years. Honeywell and other mainstream suppliers sell them. Common uv lamps also create large doses of ozone which is bad for the lungs in quantities. A doped glass version produces uv-c without ozone. It keeps the coil spotless when combined with a 4" pleated media filter. Their primary purpose is to keep pathogens from growing on the coil while maintaining system airflow efficiency. However the radiation will burn your eyes if you look at for more than a second. It will also degrade thermostat and other small gauge wire insulation which is not rated for uv-c. Ponds and rain water collection systems also use uv disinfection. These applications are normally outside the house conditioned envelope and can use the 185 nm uv with ozone which are cheaper bulbs. Operating rooms also use uv-c light banks for use between procedures, without people in the room. 185 nm produces ozone. 254 nm is used in hvac and water. When the covid pandemic started in January 2020, a run on n95 masks occurred starting in February. Medical providers like my wife no longer had them in their outpatient clinics (normally single time use with TB patients), so hospitals started using uv-c on n95 masks to allow reuse. Typically 15 minutes was adequate. I put together a homemade uv-c mask sanitizer in March 2020 using a pond ballast, timer and eventually a door switch interlock. Worked nicely. Natural sun generated uv is a primary cause of skin cancer, not a magical cure.
UV Light Improving Chances Of Fighting Cancer -- ScienceDaily UVBI Or Ultraviolet Blood Irradiation Treatment For Cancer - (anoasisofhealing.com) UV-A light technology hailed as world-first treatment for cancer - PMLiVE very promising technologies used on humans
Um, the big news is in getting closer to UV lights that are germicidal, yet safe to people, so you can have them in a room fixture, and on while people are present. This way, the pathogens shed by an infected person can be killed sooner, as they have a good chance of infecting another in the room before the HVAC system sucks them out. Current UV systems kill the pathogens, but the germs have more chances of finding a new host before reaching them. We know the far UV works for this, but a workable implementation isn't available yet.
Unfortunately the 2007 studies did not pan out. Uv can be used to activate a drug family known as Psoralens but their use can lead to skin cancer. As a result chemotherapy and gamma ray radiation are the standard cancer therapies today.
Light As Medicine? | wisconsinacademy.org UVA Light Reduced Virus Loads in COVID-19 Patients (cedars-sinai.org) Ultraviolet Light Therapy: Preparation, Recovery, Care (verywellhealth.com) UV Light for Medical Use | LightSources and LightTech (light-sources.co "Medical phototherapy lamps are used under a doctor’s supervision with specially designed lamps administering UVA, UVB and narrowband UVB emissions. Phototherapy UV lamps treat a host of medical conditions such as variety of skin conditions, mood disorders and successfully treat neonatal jaundice. Some of the most common applications of UV light for medical use include effective treatment for many skin conditions including acne, eczema, psoriasis, and vitiligo." "Ultraviolet light therapy is considered a first-line therapy for CTCL and Sézary Syndrome, and a second-line therapy for mycosis fungoides and graft versus host disease." Baby being treated for neo natal jaundice The thread title was who knew UV could be used safely in humans. The cancer study was in 2007 and didn't pan out for a number of reasons but was a medical use trail dating back to 2007. There are many other uses once the harmful part of the UV spectrum is removed. This is an interesting topic to me and fun to research
I do not yet understand the idea of a UV wavelength range that can degrade microbial cells and viruses without damage to humans and similar critters. The ones you can't be around are used in microbiology labs in addition to uses mentioned above. BTW the killer cooler in post #5 is a scary looking thing. Actually lab sterilization has an interesting side effect that may merit attention. Labs have several types of plastics 'on display' and I don't know if their UV degradation has been examined.
As a 'higher' organism, we have thicker layers of dead cells to block and absorb these UV rays before they reach delicate, living cells. Microorganisms don't have that protection. I've seen what the UV lamp in a biohood does to plastics and paint in the vicinity, but my quick search didn't find specific research for that area. Research has been done, or our headlights would be hazed up in much shorter time frames. Here's some basic overviews. Effect of Germicidal UV on Plastic Materials - Sanuvox UV and its effect on plastics: an overview | Knowledge Center | Essentra Components US Boeing is looking at the effect of these far UV rays on interior plane materials. https://www.boeing.com/confident-travel/downloads/Boeing-Compatibility-of-Aircraft-Interior-Surfaces-with-222-nm-Far-UV-Light-Exposure.pdf
