Sunday, May 25, 2008

Sun Safety (1 of 2)

By: Steven Dowshen, MD

We all need some sun exposure; it's our primary source of vitamin D, which helps us absorb calcium for stronger, healthier bones. But it doesn't take much time in the sun for most people to get the vitamin D they need, and unprotected exposure to the sun's ultraviolet rays can cause skin damage, eye damage, immune system suppression, and even cancer. Even people in their 20s can develop skin cancer.

Most children rack up between 50% and 80% of their lifetime sun exposure before age 18, so it's important that parents teach their children how to enjoy fun in the sun safely. With the right precautions, you can greatly reduce your child's chance of developing skin cancer.

Facts About Sun Exposure

The sun radiates light to the earth, and part of that light consists of invisible ultraviolet (UV) rays. When these rays reach the skin, they cause tanning, burning, and other skin damage.

Sunlight contains three types of ultraviolet rays: UVA, UVB, and UVC.

  • UVA rays cause skin aging and wrinkling and contribute to skin cancer, such as melanoma. Because UVA rays pass effortlessly through the ozone layer (the protective layer of atmosphere, or shield, surrounding the earth), they make up the majority of our sun exposure. Beware of tanning beds because they use UVA rays. A UVA tan does not help protect the skin from further sun damage; it merely produces color and a false sense of protection from the sun.
  • UVB rays are also dangerous, causing sunburns, cataracts (clouding of the eye lens), and immune system damage. They also contribute to skin cancer. Melanoma, the most dangerous form of skin cancer, is thought to be associated with severe UVB sunburns that occur before the age of 20. Most UVB rays are absorbed by the ozone layer, but enough of these rays pass through to cause serious damage.
  • UVC rays are the most dangerous, but fortunately, these rays are blocked by the ozone layer and don't reach the earth.

What's important is to protect your family from exposure to UVA and UVB, the rays that cause skin damage.

UV rays react with a chemical called melanin that's found in most people's skin. Melanin is your first defense against the sun. It absorbs dangerous UV rays before they do serious skin damage. Melanin is found in different concentrations and colors, resulting in different skin colors. The lighter your child's natural skin color, the less melanin it has to absorb UV and protect itself. The darker your child's natural skin color, the more melanin it has to protect itself. (But both dark- and light-skinned kids need protection from UV rays because any tanning or burning causes skin damage.) Also, people, especially kids, with fair complexions - lighter skin and eye color - are more likely to have freckles because there's less melanin in their skin. Although freckles are harmless, being outside in the sun may help cause them or make them darker.

As the melanin increases in response to sun exposure, the skin tans. But even that "healthy" tan may be a sign of sun damage. The risk of damage increases with the amount and intensity of exposure. Those who are chronically exposed to the sun, such as farmers, boaters, and sunbathers, are at much greater risk. A sunburn develops when the amount of UV exposure is greater than what can be protected against by the skin's melanin.

Unprotected sun exposure is even more dangerous for kids with:

  • moles on their skin (or whose parents have a tendency to develop moles)
  • very fair skin and hair
  • a family history of skin cancer, including melanoma

You should be especially careful about sun protection if your child has one or more of these high-risk characteristics.

Also, not all sunlight is "equal" in UV concentration. The intensity of the sun's rays depends upon the time of year, as well as the altitude and latitude of your location. UV rays are strongest during summer. Remember that the timing of this season varies by location; if you travel to a foreign country during its summer season, you'll need to pack the strongest sun protection you can find.

Extra protection is also required near the equator, where the sun is strongest, and at high altitudes, where the air and cloud cover are thinner, allowing more damaging UV rays to get through the atmosphere. Even during winter months, if your family goes skiing in the mountains, be sure to apply plenty of sunscreen; UV rays reflect off both snow and water, increasing the probability of sunburn.

How to Protect Your Child From the Sun

With the right precautions, kids can safely play in the sun. Here's the lowdown on the most effective strategies:

Avoid the Strongest Rays of the Day

First, avoid being in the sun for prolonged times when it's highest overhead and therefore the strongest (normally from 10:00 AM until 4:00 PM in the northern hemisphere). If your child is in the sun between these hours, as many kids are, be sure to apply protective sunscreen - even if he or she is just playing in the backyard. Most sun damage occurs as a result of incidental exposure during day-to-day activities, not at the beach.

Even on cloudy, cool, or overcast days, UV rays travel through the clouds and reflect off sand, water, and even concrete. Clouds and pollution don't filter out UV rays, and they can give a false sense of protection. This "invisible sun" can cause unexpected sunburn and skin damage. Often, kids are unaware that they're developing a sunburn on cooler or windy days because the temperature or breeze keeps skin feeling cool on the surface.

Cover Up

One of the best ways to protect your family from the sun is to cover up and shield skin from UV rays. Ensure that clothes will screen out harmful UV rays by placing your hand inside the garments and making sure you can't see your hand through them.

Because infants have thinner skin and underdeveloped melanin, their skin burns more easily than that of older kids. But sunscreen should not be applied to babies under 6 months of age, so they absolutely must be kept out of the sun whenever possible. If your infant must be in the sun, dress him or her in clothing that covers the body, including hats with wide brims to shadow the face. Use an umbrella to create shade.

Even older kids need to escape the sun. Long exposure can make them feel tired and irritable. For all-day outdoor affairs, bring along a wide umbrella or a pop-up tent to play in. If it's not too hot outside and won't make your child even more uncomfortable, you can have him or her wear a light long-sleeved shirt and/or long pants. Before heading to the beach or park, call ahead to find out if certain areas offer rentals of umbrellas, tents, and other sun-protective gear.

Updated and reviewed by: Steven Dowshen, MD

No comments: