The Science Behind Sunscreen

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The Science Behind Sunscreen

It’s the beginning of summer, which undoubtedly means more time outside. Say goodbye to everything you think you know about getting a good “base tan” and say hello to the science behind sunscreen.

When the sun hits your skin, the molecules in your skin are actually absorbing sunlight, which is made up of packets of energy referred to as photons. Unlike light we can see, light invisible to the naked eye can cause great damage to the skin. As the molecules of skin absorb light and become excited, they endure a chemical reaction. This means that spending a lot of time in the sun unprotected could really exhaust your skin’s natural protection against UV light. This makes you more susceptible to things like sunburn and wrinkles.

Since DNA itself also has the power to absorb some types of UV rays, it is possible for mutations to occur due to excess sun exposure. Ugly consequences of overexposure can include nonmelanoma or melanoma skin cancers.

Luckily, no matter your skin type, sunscreen is here to help. Sunscreen works by using molecules designed to block and reduce the number of UV rays that penetrate the skin’s surface. These molecules form a special barrier to either absorb or reflect UV photons before they have the chance to reach molecules embedded deeper in the skin.

Sunscreens are conveniently marked with SPF labels that represent the approximate time it would take for a person to get sunburned by UVB radiation. SPF 50 should provide 500 minutes of protection against the sun for a person who takes 10 minutes to burn. But, since water and sweat may decrease the longevity of any sunscreen it is best to reapply every two hours or so.

Save yourself the pain of a summer sunburn and slather on some good old-fashioned sunscreen. But, if it’s the bronzed look you’re hoping for, consult the self-tanner aisle of your local drugstore. Twenty years from now, your skin will thank you.

Photo by Michael Dorausch/Flickr, CC BY-SA 2.0

Caitlin Phillips is a freelance writer spending her summer in Budapest, Hungary.

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