Effects of the Sun
Every day, including cloudy days, the sun bombards us with ultraviolet radiation. Unchecked, these rays attack the DNA of our skin cells. Overexposure to ultraviolet A rays causes aging effects (wrinkles and spots), while overexposure to ultraviolet B causes skin to burn.
Tanning--Our Skin's Natural Protection
When exposed to UV light, our skin produces a pigment called melanin. Melanin protects us by absorbing UV like a sponge, and in the process darkens the skin. With repeated exposure the melanin level increases, the tan deepens and the risk of immediate sun burn is reduced.
Because melanin is produced very slowly, our natural protection is limited. Too much sun, too quickly, overwhelms our ability to protect ourselves and extreme cell damage ensues. Blood rushes to the burned area causing a vivid red color and the resulting inflammation triggers pain.
According to the American Academy of Dermatology, there is no "safe" way to tan. Tans and burns are both signs of skin cell damage. This damage can accelerate the aging of the skin and increase the risk of skin cancer.
Sunscreens bond to the skin, and by reflecting or absorbing the UV rays, provide additional protection. This allows us to spend more time in the sun without burning. Be sure to apply liberally and frequently, however, because sunscreen can give a false sense of security, which can itself lead to overexposure.
How Much Protection?
A sunscreens' ability to block UVB rays is rated by a multiplier, called the sun protection factor (SPF). Using a sunscreen with an SPF of 5 would allow you to spend five times as much time in the sun as you normally could without burning.