Protect your skin from the sun's damaging rays

Sunscreen is one way to protect your skin from UV rays
Warm weather is just here, which means the hours of sun time our bodies are craving are also here. But before you strip down, here are some things you should know about the sun, and sunscreen.

The American Cancer Society (ACS) estimates that every one in five Americans will be diagnosed with at least one type of skin cancer in their lifetime. The ACS also predicts that skin cancer claims 67,000 lives a year in the United States. Here are some facts, and preventative actions that will help you from becoming another statistic.

Sun basics

Some UV rays are necessary for vitamin D synthesis, but too many UV rays damage DNA in skin cells.

Sunlight reaches us in heat waves called infrared, or invisible rays called ultraviolet (UV). Ultraviolet rays, in small amounts, act as a catalyst in the manufacturing of vitamin D in our bodies.

Although some UV is necessary for our well-being, over exposure can cause premature wrinkling, skin cancer, and photokeratitis, or snowblindness. Research has shown that UV rays damage the DNA in our skin cells, putting us at higher risk for skin cancer, and permanent eye damage.

Our skin produces some UV protection in melanin, or skin pigmentation. Our skin is made of an outer layer (epidermis), and an inner layer (dermis) that contain cells which produce melanin, a pigment that absorbs UV light. Tanning happens when the skin pumps out abundant melanin from overexposure to the sun.

UV rays increase 4 percent for every 1,000-foot elevation gain. This means the sun at 10,000 feet is 40 percent stronger than at sea level. Water also reflects up to 40 percent of the UV radiation, and snow can reflect up to 90 percent.

Chances for UV damage increase with altitude and latitude. Higher elevations have a thinner atmosphere, so not only are you closer to these harmful rays, there is less atmosphere blocking them.

The same goes for the equator the closer you are to zero degrees latitude, the stronger the UVs. Water and snow also increase sun exposure by reflecting these harmful rays, penetrating your skin from every angle.

UVA rays cause aging, cancer and permanent lens damage; UVB rays cause burning, and temporary vision impairments. UV rays are divided into two categories: UVA (aging) and UVB(burning).

Until recently, sunscreens guarded against the UVB rays, but researchers at Duke have clearly found that UVA rays are just as dangerous, causing leathery, sagging skin known as photoaging, as well as cancer, and cataracts. Exposing your eyes extensively to UVB rays can also burn the cornea, which has the ability to regenerate in seven days.

However, without recuperation time, you can permanently cloud, or lose your vision entirely. Even more damaging to the eye are UVA rays that radiate past the cornea straight into the lens, forming sun cataracts from prolonged exposure. Unlike the cornea, the lens cannot regenerate itself, so reversing or halting cataract forming process is impossible.

The most dangerous type of skin cancer is malignant melanoma, which initially appears as dark moles. They can also appear as a black, blue-black or bleeding mole.

Surgical removal of the mole offers a chance in eliminating its spread, but once melanoma spreads under the skin, it is essentially incurable. The incidence of melanoma has risen 300 percent in the last 40 years in this country; 32,000 are diagnosed with it annually, according to Harrison's Principles of Internal Medicine.

Plan accordingly to avoid the sun from 10 a.m. to 3 p.m., if possible. There are many ways the outdoor enthusiast can prevent accelerated aging and skin cancer.

Avoiding the sun during the peak hours, 10 a.m. to 3 p.m., is one way. Using a quality sunscreen, and dressing appropriately (sun visors, lightweight clothing, sunglasses) are two other ways to prevent UV damage.

Sun protection

Apply sunscreen when your skin is cool and dry. This means 15 to 30 minutes before you go outside. Most sun damage occurs within the first 10 to 20 minutes of exposure. That means getting the mail, or chatting with a friend on the porch can put you at risk if you haven't applied protection before you leave the house.

Remember, the more pale your skin, the less melanin it has for absorbing UV rays, so doctors recommend applying sunscreen at least 20 minutes before you go outside. If you are using DEET and sunscreen, apply the sunscreen first for 20 minutes, then slap on the DEET.

Suncreens absorb UV rays, but can only hold so much radiation at a time. Reapply sunscreen every 30 to 60 minutes when exercising and swimming. Sunscreens work by absorbing the UV rays, preventing them from soaking into your skin, but they can only hold so many UV rays.

The sun then starts counteracting a sunscreen's function by breaking down some of its protective ingredients. That is why you need to reapply sunscreen regularly: every 30 to 60 minutes.

Your skin tone dictates which SPF (sun protection factor) you will need.

SPF stands for sun protection factor, which represents an equation for determining how long it takes protected skin to burn, compared to unprotected skin. In layman's terms, if you usually burn in 10 minutes, an SPF of 15 will provide a 150 minutes of protection.

Someone who burns at 25 minutes gets the same protection with an SPF 10 as a person who burns at 10 minutes gets with a SPF 25. So, people with fair skin need to reapply more often than people with darker skin tones.

Most sunscreens only protect against UVB rays that burn the skin, misleading people into believing that they can stay in the sun longer. Although they are not burning their skin, people sunning are exposing themselves to the cancer causing rays UVA for longer periods.

Ingredients

Titanium dioxide, and zinc oxide protect against UVA rays. Since we now know that both UVB and UVA rays are harmful, your sunscreen should contain protective ingredients for both of the UV rays.

Zinc oxide and titanium dioxide blocks most of the UVA, but aesthetically, this is not an attractive idea. Fortunately, sunscreen manufacturers have recently discovered a micronized, clear, zinc oxide and titanium dioxide.

"Broad Spectrum" does not always mean full UVA/UVB protection. People refer to these new sunscreens as broad spectrum, designed to protect against UVA and UVB rays. However, current labeling laws allow manufacturers to use the broad spectrum sticker as long as it protects against some UVA rays.

Suncreens are guaranteed for two years; less if exposed to extreme temperatures. These protective chemicals can be altered in extreme heat or freezing cold, sometimes disrupting their effectiveness.

Clothing

Clothing also offers SPF protection, but surprisingly, not all outerwear protects against UV rays.

A standard T-shirt, for instance, only offers an SPF of 6 to 8. There are, however, clothing manufacturers, such as Tarponwear International and Sun Precautions, that produce clothing with SPFs as high as 250, backed by many of their own tests.

To date, there are still no federal regulations for SPF ratings in clothing. Although many manufacturers list SPF ratings on their clothing tags, there is not yet an accreditation process to regulate these claims.

The Federal Trade Commission (FTC), together with the American Society for Testing and Materials (ASTM) are currently exploring the many outside influences on fabrics, such as salt and chlorinated water, stretch, and durability to determine a standard for clothing in relation to sun protection.

Sunglasses

As for protecting your eyes, the best prevention is wearing sunglasses, even on cloudy days. Partly cloudy days still generate 80 percent of the harmful ultraviolet radiation. The key for protection, in low end or expensive glasses, is an ASNI-280.3-1996 rating (American National Standards Institute's ophthalmic requirements).

This stamp ensures that the sunglasses block 99 to 100 percent of UVB rays, and 95 percent of UVA rays. This rating in a pair of wraparound shades that keep UV rays from seeping in from the sides, is your best source for eye protection.

Remember there is no such thing as healthy tanning. It only leads to "lizard" skin, and possibly cancer. Your best bet is to use a sunscreen that contains zinc oxide, or titanium dioxide with at least an SPF 15 and apply every 30 to 60 minutes year round.


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