There is no such thing as a healthy tan, according to dermatologists, who look at a tan and see a sign of injury. Tanned skin will forever contain cells whose genetic structures have been permanently damaged by the sun.
The sun gives off invisible rays of ultraviolet light. Ultraviolet B (UVB) rays are short, high-energy wavelengths that are absorbed by the epidermis, the outermost layer of the skin. When you burn, the skin responds to UVB rays by producing chemicals called inflammatory mediators, some of which seep down into the dermis, the skin’s middle layer. These chemicals irritate the tiny blood vessels in the dermis, which swell and create the surface redness of the burn.
At the same time, the UVB rays affect the genetic material of the epidermis, which causes the damage that may lead to skin cancer. Other UVB rays can affect the immune system and interfere with the skin’s ability to repair itself. Finally, UVB radiation attacks the skin’s melanocytes (pigment cells). The melanocytes react by stepping up production of melanin and sending melanasomes to the skin’s surface to act as a filter against the sun’s rays actually damage the DNA of the pigment cells. This kind of genetic damage causes both freckling and the mottled brown of age spots. More seriously, it contributes to the development of melanoma and other skin cancers.
Ultraviolet A (UVA) rays – longer than UVB rays – can also do lasting damage. They penetrate the skin more deeply than UVB rays, affecting the DNA of the cells in the dermis, attacking cell membranes, and changing the proteins that make up collagen and elastin, which support the skin’s fibrous structure. By undermining these parts of the skin, UVA rays lead directly to wrinkles and sagging of the skin. They also contribute to the loss of support for the skin’s tiny blood vessels, which become permanently dilated. This shows up as a general ruddiness or visible spider veins on the nose, cheeks and chin. UVA rays also play a role in the development of skin cancer.
Despite these facts, a study by the American Academy of Dermatology revealed these attitudes toward tanning among teens:
- 63% of teens believe they look better when they have a tan
- 59% of teens believe that people in general look healthier with a tan
- 43% of teens say they lie out in the sun
- 28% of female teens and 14% of male tens say they never use sun block
- Only three in ten teens who lie out in the sun say they always use sun block
In the past, the ozone layer in the atmosphere provided a blanket of protection from the sun’s damaging rays. The ozone layer in the atmosphere has been thinning over the past several years due to air pollution. As a result, the sun’s damaging rays can reach earth more easily and there has been an increase in the incidence of skin cancers.
Perhaps resulting from the commonly-held myths about tanning, there has been an increased in the use of indoor tanning beds. This is a very dangerous practice.
According to American Academy of Dermatology, indoor tanning before the age of 35 has been associated with a significant increase in the risk of melanoma, the deadliest form of skin cancer. Yet, over a million Americans, 70% of whom are girls and women, ages 16 to 29 years old, visit a tanning salon daily.
Preventing your exposure to ultraviolet (UV) radiation is the best way to diminish your chance of getting all skin cancers, including melanoma. Be sun smart. Don’t use tanning beds. Reduce your risk by protecting your skin.
For more information on sun safety and the dangers of indoor tanning, please visit American Academy of Dermatology at http://www.aad.org/public/index.html
For more information about the major types of skin cancer- basal cell carcinoma, squamous cell carcinoma, and malignant melanoma – please visit our Skin Resource Center.
|UV Index Number
|0 to 2
|3 to 4
|5 to 6
|7 to 9
The Environmental Protection Agency (EPA) and the National Weather Service (NWS) have developed an Ultraviolet (UV) Index to describe the day’s likely levels of exposure to UV rays. You may be able to find the UV Index on television, in the newspaper, and online. The Index predicts UV level using a 0-10+ scale as follows:
While you should always protect your skin, take special care to adopt safe-guards when the UV Index predicts exposure levels of moderate or higher.
Protecting the Skin
To protect against damage from the sun’s rays, it is important to avoid the sun between 10 a.m. and 4 p.m., when the sun’s rays are strongest; to wear protective clothing; and to use a sunscreen with an SPF of 15 or higher.
The time when UV exposure is likely to be greatest is between 10 a.m. and 4 p.m. during daylight savings time and during the late spring and early summer in North America. Nonetheless, protection from UV rays is important all year round. UV rays can be as strong on cloudy, hazy days as well as on bright, sunny ones.
The Shadow Rule
Another way to determine when to stay out of the sun is by following the shadow rule: “Short Shadow- Seek Shade.” The intensity of UV rays is directly related to the angle of the sun or altitude above the horizon. The shadow rule indirectly determines the sun’s altitude by observing the length of a person’s shadow during the course of the day. When a person’s shadow is shorter than the person is tall, the intensity of the UV rays from the sun is more likely to cause sunburn.
The best protective clothes are loose fitting garments made from fabric that is tightly woven. Darker colors may offer more protection than light-colored clothing, and dry clothes provide better protection than wet ones. A wide-brimmed hat that offers a lot of shade is the best choice for protecting head, face and neck. If long pants and a long sleeved shirt can’t be worn because of the temperature, it is important to wear a dry T-shirt, stay in the shade as much as possible, and always wear sunscreen.
Sunscreens provide protection by absorbing, reflecting or scattering the sun’s rays. They may also contain chemicals that interact with the skin to protect it from UV rays. Sunscreens are rated according to their effectiveness by the sun protection factor (SPF). A product’s SPF number helps determine how long the product will protect you before you need to re-apply it – how long you can stay in the sun without burning. For example, you may normally burn in 20 minutes. If you apply an SPF 15 sunscreen, you’ll be protected for about 300 minutes, or five hours (SPF 15 x 20 minutes = 300 minutes). A person with lightly pigmented skin who burns in 10 minutes would be protected for only about two-and-a-half-hours with SPF 15 (SPF 15 x 10 minutes = 150 minutes).
Sunscreens with SPF numbers higher than 15 may work well for people who have lightly pigmented skin, live at high altitudes, or work or play outdoors much of the day. To get the most protection from your sunscreen, apply it liberally at least 30 minutes before going outside and remember to re-apply it after swimming or perspiring heavily. If you’re taking medication, ask your doctor or pharmacist if it will make your skin more sensitive to the sun. Certain antibiotics, birth control pills, diuretics, antihistamines, and anti-depressants can increase one’s sensitivity to the sun’s rays.
Some people may have an allergic reaction to sunscreen. They may need to try a different brand of sunscreen or see a dermatologist.
You should always wear a sunscreen with at least SPF 15, no matter what your skin color. Even people with very dark skin can burn and develop skin cancer.
This article is from the American Skin Association