Saturday, November 14, 2009

Sun Damage

So far, you’ve heard about the good side of the sun—its ability to fuel your skin’s vitamin D factory (at least in warmer seasons). But here’s the scarypart: The dangers of the sun far outweigh its benefits.

The problem, of course, is skin cancer. Skin cancer is by far the most commonform of cancer, trouncing lung, breast, prostate, and colorectal cancers. However, many skin cancers disfigure the skin without threatening your life. Only the type of skin cancer called melanoma is likely to spread from your skin to the rest of your body, which it can do quite quickly.

The culprit is the ultraviolet radiation in sunlight. Ultraviolet rays can be divided into three types: UVA, UVB, and UVC, from least worrisome to most dangerous. UVA can age the skin and may play a role in skin cancer, but science still considers it to be the least harmful. UVB is the type of radiation that fires up vitamin D production and triggers sunburns (and eventually skin cancer). UVC is more dangerous still, but in most parts of the world it’s blocked by the ozone layer, which means it never reaches your skin.

UV exposure increases your risk for all types of skin cancer. But like many things that have adverse health consequences (smoking, obesity, and so on), there’s a lag between the behavior and its effect. In the case of skin cancer, the blistering sunburn you get in your early twenties might lead to skin cancer 30 or 40 years later. Furthermore, the effects of sun exposure are cumulative, so it may take many years of sun-inflicted damage before you harm some of your skin’s genetic material beyond repair.

Most dermatologists believe that skin cancer is highly preventable if you practice good sun habits:

• Reduce sun exposure. Don’t linger in the sun between 10 a.m. and 3 p.m. (11 a.m. and 4 p.m. during daylight-saving time). If you find yourself in strong sun, seek shade.

• Cover up. Always wear a wide-brimmed hat, long-sleeved shirt, and long pants on sunny days.

• Use sunscreen. Look for a product that protects against both UVA and UVB rays and offers a sun protection factor (SPF) of at least 15. Applied properly, a sunscreen of SPF 15 protects the skin from 93% of UVB radiation. Higher SPF numbers are better and may block more UVA, but the difference is not nearly as significant as the numbers imply.

• Use sunscreen properly. Apply sunscreen 15 to 30 minutes before going out. Repeat every two or three hours, more often if you’re swimming.

• Avoid tanning beds. Although tanning beds use UVA rays rather than the more damaging UVBs, they’re far from harmless. Even occasional tanning sessions accelerate skin aging and are likely to increase your risk of skin cancer.

• Learn from your mistakes. If you end up with a sunburn—even a mild one—figure out which rule you broke and resolve to avoid the risk next time. Remember: Sun damage accumulates over your lifetime.

These guidelines are particularly important if you have light skin, a large number of moles, or a family history of melanoma, all of which single you out for greater risk.

Despite decades of use and study, the science of sunscreens isn’t settled. Although sunscreens clearly reduce the occurrence of less harmful types of skin cancer, several studies have found that they offer no protection from deadly melanoma. The reason for this discrepancy is unknown—some experts believe sunscreen gives people a false sense of security, allowing them to stay out longer in potentially harmful sun. Others believe the culprit is not using enough sunscreen or not applying it properly, while still others blame old sunscreen formulations that failed to block UVA rays and contained now-banned ingredients. The best advice is to use sunscreen in conjunction with all the good advice in this list.

Scientists believe that skin exposure is particularly risky for children. Each severe sunburn before the age of 18 ratchets up the risk that skin cancer will develop later in life. So make an extra effort to follow these rules with children and teenagers, keep babies under one year old out of direct sun in the summer, and never leave infants playing or napping in the sun.

Source of Information : Oreilly - Your Body Missing Manual

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