Editing Ultraviolet (section)

====Sterilization and disinfection====
{{Main|Ultraviolet germicidal irradiation|Germicidal lamp}}

[[File:UV-ontsmetting laminaire-vloeikast.JPG|thumb|right|A low-pressure mercury vapor discharge tube floods the inside of a [[Fume hood|hood]] with shortwave UV light when not in use, [[Asepsis|sterilizing]] microbiological contaminants from irradiated surfaces.]]

[[Ultraviolet lamp]]s are used to [[sterilization (microbiology)|sterilize]] workspaces and tools used in biology laboratories and medical facilities. Commercially available low-pressure [[mercury-vapor lamps]] emit about 86% of their radiation at 254 nanometers (nm), with 265&nbsp;nm being the peak germicidal effectiveness curve. UV at these germicidal wavelengths damage a microorganism's DNA/RNA so that it cannot reproduce, making it harmless, (even though the organism may not be killed).<ref>{{cite news |last1=Chang |first1=Kenneth |title=Scientists Consider Indoor Ultraviolet Light to Zap Coronavirus in the Air |url=https://www.nytimes.com/2020/05/07/science/ultraviolet-light-coronavirus.html |archive-url=https://web.archive.org/web/20200507214905/https://www.nytimes.com/2020/05/07/science/ultraviolet-light-coronavirus.html |archive-date=2020-05-07 |url-access=subscription |url-status=live |website=The New York Times |date=7 May 2020 |access-date=9 May 2020}}</ref> Since microorganisms can be shielded from ultraviolet rays in small cracks and other shaded areas, these lamps are used only as a supplement to other sterilization techniques.

UVC LEDs are relatively new to the commercial market and are gaining in popularity.{{Failed verification|date=April 2020}}<ref>{{cite journal|author1=Welch, David |display-authors=et al |title=Far-UVC light: A new tool to control the spread of airborne-mediated microbial diseases|journal=Scientific Reports|volume=8|issue=1|pages=2752|doi=10.1038/s41598-018-21058-w|pmid=29426899|pmc=5807439|issn=2045-2322|date=January 2018|bibcode=2018NatSR...8.2752W}}</ref> Due to their monochromatic nature (±5&nbsp;nm){{Failed verification|date=April 2020}} these LEDs can target a specific wavelength needed for disinfection. This is especially important knowing that pathogens vary in their sensitivity to specific UV wavelengths. LEDs are mercury free, instant on/off, and have unlimited cycling throughout the day.<ref>{{cite web|url=https://www.wateronline.com/doc/coming-of-age-uv-c-led-technology-update-0001|title=Coming of Age UV-C LED Technology Update|website=wateronline.com|url-status=live|archive-url=https://web.archive.org/web/20170420045809/https://www.wateronline.com/doc/coming-of-age-uv-c-led-technology-update-0001|archive-date=20 April 2017}}</ref>

[[Disinfection]] using UV radiation is commonly used in [[wastewater]] treatment applications and is finding an increased usage in municipal drinking [[water treatment]]. Many bottlers of spring water use UV disinfection equipment to sterilize their water. [[Solar water disinfection]]<ref>{{cite web |url=http://www.sodis.ch/index_EN |title=Solar Water Disinfection |publisher=Sodis.ch |date=2 April 2011 |access-date=2011-11-08 |url-status=dead |archive-url=https://web.archive.org/web/20120831050355/http://www.sodis.ch/index_EN |archive-date=31 August 2012 }}</ref> has been researched for cheaply treating contaminated water using natural [[sunlight]]. The UVA irradiation and increased water temperature kill organisms in the water.

Ultraviolet radiation is used in several food processes to kill unwanted [[microorganisms]]. UV can be used to [[pasteurize]] fruit juices by flowing the juice over a high-intensity ultraviolet source. The effectiveness of such a process depends on the UV [[absorbance]] of the juice.

[[Pulsed light]] (PL) is a technique of killing microorganisms on surfaces using pulses of an intense broad spectrum, rich in UVC between 200 and 280 [[Nanometer|nm]]. Pulsed light works with [[xenon flash lamp]]s that can produce flashes several times per second. [[Disinfection robot]]s use pulsed UV.<ref>{{cite web|url=http://www.xenex.com/xenex-robot/|title=Video Demos|url-status=dead|archive-url=https://web.archive.org/web/20141219140317/http://www.xenex.com/xenex-robot/|archive-date=19 December 2014|access-date=27 November 2014}}</ref>

The antimicrobial effectiveness of filtered [[far-UVC]] (222 nm) light on a range of pathogens, including bacteria and fungi showed inhibition of pathogen growth, and since it has lesser harmful effects, it provides essential insights for reliable disinfection in healthcare settings, such as hospitals and long-term care homes.<ref>{{Cite journal |last1=Lorenzo-Leal |first1=Ana C. |last2=Tam |first2=Wenxi |last3=Kheyrandish |first3=Ata |last4=Mohseni |first4=Madjid |last5=Bach |first5=Horacio |date=2023-10-31 |editor-last=Barbosa |editor-first=Joana |title=Antimicrobial Activity of Filtered Far-UVC Light (222 nm) against Different Pathogens |journal=BioMed Research International |language=en |volume=2023 |issue=1 |pages=1–8 |doi=10.1155/2023/2085140 |issn=2314-6141 |pmc=10630020 |pmid=37942030 |doi-access=free }}</ref> UVC has also been shown to be effective at degrading SARS-CoV-2 virus.<ref>{{cite journal | doi=10.1021/acsphotonics.3c00828 | title=Mechanisms of SARS-CoV-2 Inactivation Using UVC Laser Radiation | date=2023 | last1=Devitt | first1=George | last2=Johnson | first2=Peter B. | last3=Hanrahan | first3=Niall | last4=Lane | first4=Simon I. R. | last5=Vidale | first5=Magdalena C. | last6=Sheth | first6=Bhavwanti | last7=Allen | first7=Joel D. | last8=Humbert | first8=Maria V. | last9=Spalluto | first9=Cosma M. | last10=Hervé | first10=Rodolphe C. | last11=Staples | first11=Karl | last12=West | first12=Jonathan J. | last13=Forster | first13=Robert | last14=Divecha | first14=Nullin | last15=McCormick | first15=Christopher J. | last16=Crispin | first16=Max | last17=Hempler | first17=Nils | last18=Malcolm | first18=Graeme P. A. | last19=Mahajan | first19=Sumeet | journal=ACS Photonics | volume=11 | issue=1 | pages=42–52 | pmid=38249683 | pmc=10797618 }}</ref>