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| Sun Protection \ Fallene Total Block |
Light Spectrum Information
|  Ultraviolet C (UVC) - 100 –290nm
These wavelengths are the shortest ultraviolet rays, extending from 100nm to 290nm, and are the most carcinogenic. While the sun generates ultraviolet C, the ozone layer of the atmosphere screens out virtually all UVC from reaching us.
Ultraviolet C may become a problem for those living at high altitudes, and with the depletion of the ozone layer through pollution, may become a real problem. UVC is photo damaging to the skin, causing skin burn with exposure. Artificial sources such as some mercury arc-welding units, and germicidal lamps emit ultraviolet C.
These wavelengths can very efficiently kill germs, giving rise to their common name, “germicidal waves”.
Ultraviolet B (UVB) – 290nm to 320nm
These are the intermediate wavelength of Ultraviolet rays, and cause the initial appearance of redness, commonly called “sunburn”. UVB creates painful irritation, but is believed by many to be less damaging than tanning, the pigmentation changes caused by the UVA (320nm-400nm).
UVB primarily damages the epidermis resulting in skin redness promoting a thickening of the outer most layer of skin, the stratum corneum (our body’s attempt to reduce UVB impact on the epidermis). UVB is a promoter of photo aging. This type of damage is cumulative, potentially resulting basal cell and squamous cell cancers.
Ultraviolet A (UVA) – 320nm – 400nm
These longer UVA wavelengths, (near-UV) were once thought essentially harmless, contributing only to a “healthy tan”. Scientific evidence now indicates that this is not true. On skin, UVA induces cutaneous photo damage, dryness, uneven pigmentation, inflammation, skin darkening (tanning), photo aging skin cancer, and fine wrinkles.
Even low dose UVA can reach to the underlying dermis, causing damage that results in wrinkles and sagging skin. UVA radiation penetrates deeply into our skin and is quite damaging. Furthermore, UVA adversely affects the deep dermis far more than the “sunburn” UVB rays, resulting in loss of the elastic it’s supportive collagen, and resulting in premature aging. Unlike the shorter UVB (290-320nm) wavelengths, UVA easily penetrates window glass.
Interestingly, the amount of UVA reaching the earth, unlike UVB retains essentially the same energy level every day of the year, morning, noon, and afternoon with 10 to 12 times more UVA, then UVB reaching the earth’s surface at sea level. UVA protection is not numerically addressed although you may see UVA and broad-spectrum protection on a package. The SPF rating system does not predict the ability of sunscreens to block UVA wavelengths.
The most important aspect of UVA is the cumulative tissue damage that results from these deeply penetrating UV rays. Studies to date support the relationship of such UV exposure to the development of basal and squamous cell cancers, as well as pre-cancerous lesions.
Recently, it has been reported that depletion of Vitamin A in the skin by UVA exposure may contribute to both photo aging and cancers of the skin.- Deeply penetrating UVA radiation presents the same damaging effect to the skin in mid-December at 9:00 in the morning as it does in mid-July at 1:00 in the afternoon.
- That is why those of us with sensitivities to light, whether the cause is genetic, disease (such as Lupus and Rosacea) or drug related (as with certain antibiotics and diuretics) or related to photodynamic therapy [PDT], need year-round, everyday, morning-to-night protection from all forms of light.
Visible Light - 400nm – 760nm
Nearly 50% of the sun’s radiation, reaching us at sea level, is within the visible range. As the name describes, these are the wavelengths that humans can see (Violet – Blue – Yellow – Green – Orange, Red, etc.). Distributed from approximately 400nm to 760nm fortunately, its energy level is lower than that of ultraviolet rays.
There have been a few published reports, regarding the research concerning photodamage caused by visible light. It has, however, been reported in prestigious journals such as, the “Journal of Investigative Dermatology”, “Cancer Research”, and the “British Journal of Dermatology”, that visible light is capable of precipitating phototoxic reactions, promoting DNA cross-linking and enhancing tumor growth.
This lower energy has the ability to penetrate the skin deeper than UVA, reaching down within the dermis. Adverse skin reactions can occur within this visible light wavelength. It is a misconception to think visible light as being harmless to human skin.
Infrared- “IR” - greater than 760nm to 1,000,000nm
Infrared goes from above 760nm to infinity, but most of the energy is from 760nm to about 1800nm, comprising more than 40% of the sun’s rays reaching us at sea level. These wavelengths warm us when we stand in the sun (perceived as deeply penetrating heat), and are emitted by stoves, furnaces, light bulbs, heat lamps, ovens, and space heaters.
A number of studies have implicated Infra Red waves as photodamaging, and add to the UVB photodamage. Infrared has been known for centuries to cause cancers in some people. Cancers induced by such heat are referred to as; Kang Cancer in China, Kangri in Kashmir, Kairo in Japan, and Peat Fire Cancer in Ireland.
Chronic exposure to infrared leads mottled pigmentation, loss of elastin elastosis, and the typical characteristics seen in photoaged skin. (wrinkling, sagging, leathery-feel).
Information and graphic provided by Fallene, Ltd. |
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