The best way to prevent skin damage, in any case, is to avoid episodes of excessive sun exposure. The following are some specific guidelines:
• Use sunscreens that block out both UVA and UVB radiation. However, do not rely on them only for sun protection. Also, wear protective clothing and sunglasses.
• Avoid exposure particularly during the hours of 10 AM to 4 PM when sunlight pours down 80% of its daily UV dose.
• Avoid reflective surfaces, such as water, sand, concrete, and white-painted areas. (Clouds and haze are not protective and in some cases may intensify UVB rays.)
• Ultraviolet intensity depends on the angle of the sun, not heat or brightness. So the dangers are greater the closer to the summer-start date. For example, in the Northern Hemisphere, UV intensity in April (two months before summer starts) is equal to that in August (two months after summer begins).
• The higher the altitude the quicker one sunburns. (One study suggested, for example, that an average complexion burns at six minutes at 11,000 feet at noon compared to 25 minutes at sea level in a temperate climate.)
• Avoid sunlamps, and tanning beds or salons. They provide mostly high-output UVA rays. Some experts believe that 15 to 30 minutes at a tanning salon is as dangerous as a day spent in the sun. People should not be misled by advertising claims of “safe” tanning or promotions offering unlimited tanning.
The use of sunscreens is complex and everyone should understand how and when to use them. The bottom line is not that people should avoid sunscreens or sunblocks, but that they should always use them in combination with other sun-protective measures.
Wearing sun-protective clothing is extremely important and protects even better than sunscreens. Special clothing is now available for blocking UV rays and is rated using SPF ratings or a system called the UPF (ultraviolet protection factor) index, with 50 UPF being the highest. (According to one study, this is a very reliable indicator of protection.) The clothing is expensive, however. The following are some tips for anyone:
• Everyone, including children, should wear hats with wide brims. (Even wearing a hat, however, may not be fully protective against skin cancers on the head and neck.)
• People should look for loosely fitted, unbleached, tightly woven fabrics. The tighter the weave, the more protective the garment.
• Washing clothes over and over improve UPF by drawing fabrics together during shrinkage. An easy way to assess protection is simply to hold the garment up to a window or lamp and see how much light comes through. The less the better.
• Everyone over age one should wear sunglasses that block all UVA and UVB ray.