Experts say a suntan is the skin's response to sun damage and that too much sun can cause long-term harm and skin cancer. "There is no such thing as a safe tan. Even a healthy-looking tan is the result of the skin attempting to repair itself," cautions Dr. Alan Moshell, Director of the Skin Diseases Branch of the National Institute of Arthritis and Musculoskeletal and Skin Diseases, a component of the National Institutes of Health.

The redness, pain and blistering of a sunburn is the skin's reaction to the effects of ultraviolet radiation. It is made up of ultraviolet A (UVA), ultraviolet B (UVB) ; and ultraviolet C (UVC). Ultraviolet B (UVB), which causes the most immediate damage to the skin, varies in intensity throughout the day and is strongest during the summer months.

The sun accelerates the natural aging of the skin, leaving it vulnerable to future damage. "Repeated sunburns and prolonged sun exposure cause cumulative damage to the skin that may not be noticeable right away, " explains Moshell. Over time, sun-exposed skin can become dry, wrinkled, and in some cases, discolored.

This premature aging of the skin usually results from overexposure to both ultraviolet A (UVA), which penetrates the skin more deeply than UVB, and UVB. Levels of UVA vary less during the year than UVB, and like UVB, can neither be seen nor felt.

Although some newer sunscreens are more effective in blocking both UVA and UVB than those previously available, it is always wise to limit your time in the sun.--an NIH HEALTHWise report, July 1997

Be HealthWise

• Stay out of the sun between 10 a.m. and 3 p.m., when the sun's rays are strongest.
• If you are going to be in the sun for any length of time, find an area with "structured shade", such as a wooded clearing, to block as much of the sun as possible. The sun is strongest at the beach, where sand and water reflect the sun's damaging rays.
• Always apply a generous, uniform amount of sunscreen with an SPF (sun protection factor) of at least 15. Reapply regularly if you go swimming or stay in the sun for a long time.
• If the sunscreen is waterproof, let it dry 30 minutes before going in the water.
• Use sunscreen even on cloudy days, especially if you plan to be outside for any length of time.
• Keep young infants out of the sun. Start using sunscreen on children at 6 months of age and limit their exposure. Sunscreens are not approved for infants younger than 6 months.
• Wear sunglasses and protective clothing, such as hats. If you burn easily, longsleeved shirts and long pants can provide added protection.
• Avoid tanning salons and lamps, which produce ultraviolet radiation that can damage your skin just like sunlight.

For more information, reporters can contact:

Mary Sullivan
Editor, NIH News & Features magazine
Phone: 301-496-1766
FAX: 301-402-0395
E-mail: ms41x@nih.gov

For an information package on "sun and skin" (fact sheet, patient information and technical articles), please contact:

NAMSIC
National Institutes of Health
Attn: HEALTHWise
1 AMS Circle
Bethesda, MD 20892-3675

Phone: 301-495-4484
Fax: 301-587-4352
TDD: 301-565-2966