It is estimated that one of five people will have cancers will be the result of ultraviolet (UV) radiation from the sun and tanning beds. UV rays penetrate into the dermis and generate free radicals that can alter our DNA, the genetic material of all living cells.
Natural sunlight has a germicidal effect and produces vitamin D in the skin. UV radiation can be used to treat rickets, psoriasis, and acne. Exposure to UV rays also stimulates the skin & # 39; But deep tanning is another matter, and what a deep tan may look healthy, it is really a sign that the skin is under attack from UV radiation.
With each blistering sunburn, the chance of developing, the chance of developing the UV rays. The degree of redness is an indication of the amount of damage done to the skin. Smoking also increases UV damage due to the formaldehyde produced in cigarette smoke.
About 35 percent is visible light, 60 percent is infrared radiation, and 5 percent is made up of UV rays. UV wavelengths range from 200nm to 400nm and are further divided as follows:
UVC rays (from 200-290 nm) are the most energetic, but are the least penetrating. UVC rays are not a concern because most UVC radiation is blocked by ozone in the atmosphere and never reaches the earth.
UVB rays (from 290-320 nm) frequently responsible for occurrence erythema and tanning. Erythema is used to measure the effectiveness of sunscreens and indicating the sunscreen & # 39; s ability to block UVB rays. This measurement is known as the Sun Protection Factor (SPF).
An SPF 2 blocks 50% of UVB and an SPF of 30 blocks 96.9 percent of UVB. Not doubling the SPF does not double the UVB sunscreens include: ethylhexyl methoxycinnamate, ethylhexyl salicylate, homosalate, octocrylene, phenylbenzimidazole sulfonic acid, benzophenone and titanium dioxide.
UVA rays (from 320-400 nm) are the longest wavelengths of ultraviolet radiation and the closest to visible light. UVA is commonly known as "black light." UVA plays only a minor role in erythema and tanning, as obvious or acute as UVB, UVA exposure is every bit as damaging. UVA wavelengths are the least energetic, but penetrate the deepest. since UVA penetrates into the dermis, it contributes substantially to chronic sun damage.
Remember that protection from UVB rays. A sunscreen with a high SPF may provide adequate protection from UVB rays but offer little or no protection from UVA exposure. Make sure the sunscreen you use contains both UVB and UVA protection. Approved UVA sunscreens include: avobenzone, benzophenone-3, oxybenzone, octocrylene, menthyl anthranilate, butylmethoxydibenzoylmethane, and zinc oxide.
One Food and Drug Administration (FDA) released a new Sunscreen Monograph on August 27, 2007. The FDA proposal offer a rating system for UVA sunscreen products on a scale of one to four stars. medium protection, three starts high protection and four times the highest UVA protection available in non prescription sunscreen products.
Traditional organic sunscreens protected by chemically absorbing UV rays. Inorganic sunscreens reduce the potential for There is also some concern about unwanted chemical reactions that may take place on the skin when organic sunscreens absorb UV rays.
UV radiation is not referred to UV light, UV rays are invisible and not really light at all. Since you can not see the UV rays that cause sunburn, it 's advisable to protect yourself from the sun even on cloudy days. though clouds block visible light, they offer little protection from damaging UV rays.
Self-tanning products make it possible to tan safely without the sun. S surface to turn them golden brown and simulate a natural tan.
The Food & Drug Administration (FDA) current ruling regulating the manufacture and labeling of sunscreen products became effective on January 1, 2003. A new proposal FDA regulation will make some changes and improvements in the current regulations.
1. The FDA ruling will provide a four star rating system for UVA protection.
2. Maximum not aware that SPFs over 30 provide little added protection and greatly increase the concerns associated with high concentrations of organic sunscreen ingredients. Product label is currently SPF 30 or SPF 30 plus. New new FDA proposal raises the ceiling on SPF values to 50+. For maximum protection, apply sunscreen 20 minutes before going out in the sun. Apply evenly and generously and reapply every hour.
3. It is no official definition of the term "natural" and all sunscreen products contain chemicals, and terms "natural," "non-chemical," and "chemical free" are considered false and misleading and are not approved. and zinc oxide are inorganic chemicals.
4. Because all sunscreens allow some UV rays to penetrate the skin, the term "sunblock" is not approved.
