In a child's eyes, the sun is central to life. How many crayon creations include a large yellow splotch representing the solar phenomenon? Not only does the sun provide light and life on our planet, it also helps our skin cells to manufacture vitamin D, which may prevent osteoporosis and depression as well as prostate and breast cancers. In short, we could not exist without the sun and, throughout history, people have gone so far as to worship it as a deity.

Unfortunately today, despite its many benefits and its singular beauty, the sun is most often seen as a culprit. Over the past three decades, studies have proven that over-exposure to the sun may increase the risk of skin cancer, which is the most common form of cancer in the U.S. According to the Centers for Disease Control and Prevention, 61,646 people were diagnosed with melanomas of the skin and 9,199 people died from skin cancer during 2009 alone.

Sun safety, then, is never out of season but the summer months usually mean more outdoor activities, including sun-filled picnics and hours spent swimming in the pool or playing at the beach. Although it is healthy to enjoy out-of-doors physical activity, over-exposure to the sun will easily lead to burns. Because of the pain involved, sunburn is easy to understand as harm done to your skin but tanning may also be a sign of damage. In fact, it is your skin's reaction against invisible, though dangerous ultraviolet (UV) radiation; tanning occurs when your skin produces additional pigmentation to provide it with some - but often not enough - protection from hurtful UV radiation. And not only may UV rays cause skin cancer, they may also induce eye problems and weaken your immune system while producing unattractive wrinkles and spots.

Clearly, it is important to guard against over-exposure to UV radiation.

Sunlight and Shadow

One of the best ways of limiting your UV exposure is to find a spot in the shade whenever possible. If you are unsure about the strength of the sun's rays, use the shadow test: if your shadow is shorter than you are, which usually occurs between the hours of 10 a.m. and 2 p.m., then the sun's rays are at their strongest. Protect yourself by staying in the shade as much as possible during these hours. Be especially careful on the beach or in any area with sand and water because these surfaces reflect sunlight, increasing the amount of UV radiation you receive. UV rays also reach below the water's surface, so you may burn even while swimming.

Typically, windows, including those in your car, home, and office, offer some protection. "But you can still be over-exposed to the sun while driving," said Dr. Angela Lamb, M.D., director of the Westside Mount Sinai Dermatology Faculty Practice. "Glass blocks the UVB (burning) rays, but not all of the UVA (aging) rays." Although the radiation coming through windows may not pose the greatest of risks, too much time close to a window receiving direct sunlight can be harmful.

"Even if it is an overcast day, you may be exposed to harmful rays," said Lamb. On an overcast day, up to 80 percent of the sun's UV rays can get through the clouds. Before going outside, check the UV Index, which can be found in many forecasts as well as on the Environmental Protection Agency's web site.

Those who need to be especially careful of sunlight are people who have:

  • pale skin
  • blond, red, or light brown hair
  • been treated for skin cancer
  • a family member who has had skin cancer
  • people on certain medications (ask your doctor)

Everyone is vulnerable to the harmful effects of over-exposure to UV radiation. A few simple precautions, however, will help you avoid damage from too much sun.

Slip! Slop! Slap! Wrap!

To prevent sun-related skin cancer, the National Council on Skin Cancer Prevention recommends you and your family to:

  • slip on a shirt
  • slop on sunscreen of SPF 15 or higher
  • slap on a wide-brimmed hat
  • wrap on sunglasses

Dress with Care

If you plan on being outside on a sunny day, cover as much of your body as possible. Wear a wide-brimmed hat, long sleeves, and pants. There are many thin but cool sun-protective fabrics available. Dark colors generally provide more protection than light colors. A tightly woven fabric protects better than loosely woven clothing. Dry fabric is generally more protective than wet fabric.  

Some companies now make clothing that protects against UV exposure even when wet. These sun-protective clothes may have a label listing the UV protection factor (UPF) value on a scale from 15 to 50+. The higher the UPF, the higher the protection. Newer products, which are used in the washing machine, can increase the UPF value of clothes you already own without changing color or texture. They are meant to add a layer of UV protection, though it's not clear how much they help.

Be aware that covering up doesn't block out all UV rays so it is important to follow other steps to protect yourself.

Sunscreen

Applied to the skin for protection against the sun's UV rays, sunscreens are available in many forms - lotions, creams, ointments, gels, sprays, wipes, and lip balms. Some cosmetics, such as lipsticks and foundations, also contain sunscreen. 

"For people with a history of skin cancer, I tell them to wear sunscreen everyday, like it is their job," said Lamb. "For patients that are concerned about discoloration and aging, I say the same. If someone has not had skin cancer and is just concerned about if they should or should not wear sunscreen, I tell them to wear it if they are going to be outside for longer than 5- 10 minutes."

Check product labels to make sure you get a "sun protection factor" (SPF) of 15 or more and broad spectrum protection. SPF 15 sunscreens filter out about 93 percent of UVB rays, while SPF 30 sunscreens filter out about 97 percent, SPF 50 sunscreens about 98 percent, and SPF 100 about 99 percent. The higher you go, the smaller the difference becomes. Apply the recommended amount evenly to all uncovered skin, especially your lips, nose, ears, neck, hands, and feet. Generally, you should apply sunscreen 15 minutes before going out in the sun and reapply at least every two hours. Check the expiration date on the sunscreen container to be sure it is still effective. Although some sunscreen products can irritate your skin, many products are hypoallergenic or dermatologist-tested.

  • Ask a health care professional before applying sunscreen to children under 6 months old.
  • Apply sunscreen to children older than 6 months every time they go out.

Just as clothing does not block all the harmful rays, proper sunscreen also will not perfectly protect you, so it is important to combine forms of sun protection.

Sunglasses

UV-blocking sunglasses are important for protecting the delicate skin around the eyes, as well as the eyes themselves. Tips for eye-related sun safety include:

  • Buy sunglasses with a label that offers 99 to 100 percent UV protection.
  • Ask an eye care professional to test your sunglasses if you don't know their level of UV protection.
  • People who wear contact lenses that offer UV protection still need sunglasses.
  • Wrap-around sunglasses offer the most protection.
  • Children need real, not toy sunglasses, just like adults.