“The sun,--the bright sun, that brings back, not light alone, but new life, and hope, and freshness to man--burst upon the crowded city in clear and radiant glory. Through costly-colored glass and paper-mended window, through cathedral dome and rotten crevice, it shed its equal ray.”
Charles Dickens, Oliver Twist
Ultraviolet radiation is a powerful natural element, it provides essential vitamins as well as kills germs, and bacteria. Here’s some facts about Ultraviolet radiation.
Ultraviolet (UV) stops infectious disease
A: Ultraviolet C (UVC) radiation is a disinfectant for air, water, and nonporous surfaces. UVC has been used for decades to reduce the spread of bacteria. UVC radiation has been shown to destroy the outer protein coating of the SARS-Coronavirus (variant of COVID19). The destruction ultimately leads to stopping the virus.
To effectively use UVC there are two variables needed-
Direct exposure:
UVC needs direct exposure on the “affected area”. If soil, dust or other contaminants are blocking the UV radiation will not work effectively.
Dose and duration:
Many of the UVC lamps sold for home use are produce a low dose of radiation, so it may take longer exposure to a given surface area to potentially provide effective stopping of a virus.
Bonus Info!
UVC radiation is commonly used inside air ducts to disinfect the air.
Sunshine (Natural UVC radiation) has real health benefits
• Visible light helps keep circadian rhythms in natural order (Circadian rhythms are physical, mental, and behavioral changes that follow a 24-hour cycle. These natural processes respond primarily to light and dark and affect most living things, including animals, plants, and microbes).
• Sunlight can help your body produce vitamin D. (Vitamin D helps bone, brain, and heart health work more effectively).
• Exposure to sunlight helps to increase the brain’s release of the hormone serotonin. Serotonin is associated with boosting mood and helping a person feel calm and focused.
• UV light has been used for decades as a natural disinfectant. It’s used to clean drinking water as well as in some environments, like hospitals and medical facilities, to naturally eradicate organisms that could be potentially harmful.
UVC lamps can be used to disinfection at home (with caveats
Information on how well “home use” UVC lamps work at stopping infectious diseases is unknown. Basically, there’s not enough published data about the wavelength, dose, and duration of UVC radiation required to kill a virus.
To learn more about a specific UVC lamp, you may want to:
• Ask the manufacturer about the product’s health and safety risks and about the availability of instructions for use/training information.
• Ask whether the product generates ozone.
• Ask what kind of material is compatible with UVC disinfection.
• Ask whether the lamp contains mercury. This information may be helpful if the lamp is damaged, and you need to know how to clean up and/or dispose of the lamp.
Risks to using UVC lamps
UVC lamps has potential health and safety risks depending on the UVC wavelength, dose, and duration of radiation exposure. The risk may increase if the unit is not installed properly or used by untrained individuals.
• Direct exposure of skin and eyes to UVC radiation from some UVC lamps may cause painful eye injury and burn-like skin reactions. (Never look directly at a UVC lamp source, even briefly).
• Some UVC lamps generate ozone. Ozone inhalation can be irritating to the airway.
• UVC can degrade certain materials, such as plastic, polymers, and dyed textile.
• Some UVC lamps contain mercury.
Not all UVC lamps are made equally
UVC Lamps may emit very specific UVC wavelengths (like 254 nm or 222 nm), or they may emit a broad range of UV wavelengths. Some lamps also emit visible and infrared radiation. The wavelengths emitted by the lamp may affect the lamp’s effectiveness at killing a virus and may impact the health and safety risks associated with the lamp.
Types of UVC radiation Lamps
Low-pressure mercury lamp: Low-pressure mercury lamp, which has its main (>90%) emission at 254 nm. Other wavelengths are also produced by this type of lamp.
Excimer lamp or Far-UVC lamp: Type of lamp, called an “excimer lamp”, with a peak emission of around 222 nm.
Pulsed xenon lamps: Emit a short pulse of broad spectrum (including UV, visible and infrared) light have been filtered to emit mainly UVC radiation and are sometimes employed in hospital settings to treat environmental surfaces in operating rooms or other spaces. These are normally employed when no humans are occupying the space.
Light-emitting diodes (LEDs): Light-emitting diodes (LEDs) that produce UV radiation are also becoming more commonly available. Typically, LEDs emit a very narrow wavelength band of radiation. Currently available UV LEDs have peak wavelengths at 265 nm, 273 nm, and 280 nm, among others.
Sources:
https://www.fda.gov/medical-devices/coronavirus-covid-19-and-medical-devices/uv-lights-and-lamps-ultraviolet-c-radiation-disinfection-and-coronavirus
https://www.nationalacademies.org/based-on-science/covid-sunscreen#:~:text=Scientists%20are%20still%20studying%20whether,sun%20destroys%20the%20coronavirus.
https://www.healthline.com/health-news/want-to-kill-dangerous-germs-open-your-blinds#The-bottom-line
https://www.skincancer.org/blog/can-ultraviolet-light-kill-germs/