![]() Blood vessels dilate in the dermis, the layer below the epidermis, to nourish that outermost layer. This mounting DNA damage gets the body’s attention. “The nice spiral staircase is knocked off-kilter,” says Darrell Rigel, a clinical professor of dermatology at New York University Medical Center and an educational spokesperson for the Skin Cancer Foundation. (Think of the AT and the CG bonds as the steps in DNA's twisting staircase.) UVB messes up this chemistry by creating what’s known as a thymine dimer, when two Ts next to each other join together. In the twisting double helix of DNA, four molecules called nucleotides form regular cross-links: Adenosine binds to thymine (AT), and cytosine binds to guanine (CG). Still, those with darker complexions remain at risk for overexposure to damaging rays because melanin is not impervious to all UV rays this means that rays can sneak in and cause instant damage to the DNA in the cells in the epidermis (the outermost layer of the skin.) “This somewhat protective mechanism isn’t even available to everybody,” she says. People with fair skin, however, possess very little melanin to send to the front lines, according to Rachel Herschenfeld, a dermatologist at Dermatology Partners, Inc., a private practice located in Wellesley, Massachusetts. This process is called immediate pigment darkening, which helps to better cover cell nuclei where DNA resides. When you’re exposed to sunlight, the melanin in the skin goes on the defensive and redistributes itself. The amount and the kinds of melanin you have in and in between your skin cells determines skin color, and the darker you are, the more natural protection you have against UV. Some of that warmth you feel comes from the absorption and conversion of UV rays to heat by two kinds of pigment molecules collectively called melanin. You step out into the bright sunlight and soak in its radiance and warmth. Here’s a rundown of how your skin goes from sun-kissed to sun-dissed. But if you forget your sunscreen and give the sun’s rays an open shot at your skin, what’s happening at the cellular level as UV rays wreak havoc? A lot of factors significantly impact how quickly and badly one sunburns, including color of skin, cloud cover, and time of day. With our hemisphere tilted more toward the sun in summer, and with a natural seasonal dip in ozone, it’s the most dangerous time for skin damage.Ī good sunscreen, applied liberally and often, is your friend on hot summer days. ![]() Our planet’s ozone layer shields us from much of this UV radiation, and almost entirely absorbs a third kind, UVC, the most energetic and dangerous. The UV we usually contend with comes in two flavors: UVA, which primarily causes wrinkling, and the stronger UVB, which produces the telltale signs of sunburn. The source of sunburn's dermatological damage is ultraviolet (UV) rays, a more energetic form of light than what we use for vision. Overexposure puts us at risk for sunburn and in turn, melanoma, the deadliest type of skin cancer. ![]() ![]() But too much of a good thing can be dangerous and rays of sunlight are no exception. For example, it helps release serotonin, the feel-good chemical produced by the brain. Sunlight in moderation and with proper protection (like using SPF) is good for us. Summer brings with it beach trips, barbecues, and several other outdoor activities that typically have us soaking up rays of sunshine.
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