Sunscreen 101

Summer’s here, and you’re probably spending more time outdoors. You already know it s important to bring your sunscreen, but some researchers say you may not be using it correctly!

According to the National Center for Chronic Disease Prevention and Health Promotion, exposure to the sun’s ultraviolet (UV) rays appears to be the most important environmental factor in developing skin cancer. UV radiation is also a factor in the development of lip cancer.

According to University of Alabama at Birmingham dermatologist Conway Huang, M.D., while many surveys show that more people are aware that the sun’s radiation causes skin cancer, skin cancer cases are rising faster than any other cancer. “Even though people know about the correlation between the sun’s rays and skin cancer, their behavior hasn’t changed significantly,” says Huang.

For many of us, prevention means slopping on any strength sunscreen before we hit the beach, the tennis courts or even the back yard. This may only cause a false sense of security. “People generally don’t use sunscreens right,” says Martin A. Weinstock, M.D., Ph.D. “They may not put it on until after they’ve been in the sun, they spread it unevenly or don’t reapply it after they sweat.” Weinstock is a professor of dermatology at Brown University, and chairman of the American Cancer Society Skin Cancer Protection Federation and chief of dermatology at the VA Medical Center in Providence, R.I.

Survey Shows
A study appearing in the May 2001 issue of the Journal of the American Academy of Dermatology bears him out. In the study, co-author and dermatologist Richard F. Wagner, M.D., found the majority of people using sunscreen return home sunburned because they didn t use it correctly. “Sunburn is a common injury for many people during the summer months and one that is highly preventable,” says Wagner.

The researchers, from the department of dermatology, University of Texas Medical Branch, Galveston, Texas, interviewed 67 adult beachgoers at a popular public beach in Galveston, Texas, over a Fourth of July weekend. They asked about sun-related activities and habits. Each person answered questions about the following:

Their sun-protection habits including sunscreen and whether they used other sun protective items like hats, clothing and sunglasses

  • Parts of the body where sunscreen was applied
  • The number of times previously sunburned
  • Number of hours spent at the beach
  • How often sunscreen was reapplied throughout the day.

They found that 73 percent of those who applied sunscreen became sunburned, many because they didn’t apply enough or didn’t reapply it as often as they should – especially swimmers. “In general, we found that swimmers who used sunscreen and didn t reapply it after leaving the water were significantly more likely to be sunburned than non-swimming sunscreen users,” says Wagner.

In the study, women did better than men. The study found 78 percent of the women interviewed used sunscreen, while only 34 percent of the men did. Besides being more conscientious, women were also more efficient: 69 percent of women applied sunscreen to their entire exposed skin areas versus 14 percent of the men.

Cancer of the skin is the most common of all cancers. The American Academy of Dermatology (AAD) says skin cancers are divided into two general types:

  • Melanoma
  • Non-melanoma

Melanoma accounts for about 4 percent of skin cancer cases but causes about 79 percent of skin cancer deaths. This year the American Cancer Society (ACS) estimates more than 51,000 people in the United States will be diagnosed with melanoma – a 9 percent increase from 2000. In addition, approximately 7,800 deaths will be attributed to melanoma in 2001.

The outer skin – or epidermis – is very thin, averaging only about one-hundredth of an inch. Melanoma originates in the melanocytes, the cells that produce the skin coloring or pigment known as melanin. Non-melanoma skin cancers – usually basal cell (BCC) and squamous cell (SCC) cancers – are the most common skin cancers with more than 1 million new cases diagnosed every year in the United States. Of the two, BCCs are by far the most common, accounting for about 80 percent of the non-melanomas. When BCCs and SCCs are detected and treated at an early stage, they are almost invariably cured.

Who’s at Risk?
According to the ACS and the AAD, the six largest risk factors for developing malignant melanoma are:

  • having unusual looking moles and/or an increase in the number of freckles on the body
  • history of three or more years of an outdoor summer job as a teenager
  • history of three or more blistering sunburns prior to age 20
  • presence of red or blond hair
  • personal history or family of malignant melanoma
  • presence of marked freckling on the upper back

 

Huang says you can minimize your chance of developing melanoma with simple behavioral changes. He says the most important things to remember can be summarized by three main points. He calls them the photo-protection triad :

Sun avoidance. Avoid sun exposure during the most intense hours of 9 a.m. to 4 p.m.

Sun protection. If you must go out, wear long sleeves, pants and a wide-brimmed hat whenever possible.

Sunscreen. Use a broad-spectrum high sun protection factor (SPF) sunscreen, number 15 or greater. Remember to reapply every few hours.

“Don’t forget to apply sunscreen to all exposed areas, including your ears and under your chin,” says Huang. “Sand, water and even white concrete can reflect the sun’s rays from below.”

The American Academy of Dermatology’s offers additional recommendations:

  • Use sunscreens every day if you are going to be in the sun for more than 20 minutes.
  • Apply sunscreens to dry skin 15 to 30 minutes before going outdoors.
  • One ounce of sunscreen, enough to fill a shot glass, is considered the amount needed to cover the exposed areas of the body completely.
  • Reapply sunscreen every two hours or immediately after swimming or strenuous activity.
  • Limit exposure during peak hours.
  • UV rays from artificial sources of light, such as tanning beds and sun lamps, are just as dangerous as those from the sun and should also be avoided.

Weinstock says parents should be particularly careful with children. He says a recent nationwide survey of children ages 11 to 18 showed many were developing sunburns despite using sunscreens of SPF 15 or greater. “Prevention now will prevent problems later in their lives,” he says.