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Why does the skin tan?
WHY CORNER

KnowHow team explains: Go to any beach and you are sure to find sun worshippers baking their bodies in the sun, totally oblivious to the fact that the sunburns they acquire may develop into skin cancers 10 to 20 years later. In most parts of the world, tanning is considered to be the “in” thing, as opposed to the earlier times when pale skin was preferred. It was thought that the paler one’s skin the higher was the class, and men and women went to great (and sometimes unhealthy) lengths to be pale.

Tans are natural shields against the sun’s ultraviolet (UV) radiation, which can damage skin tissue by causing sunburns as well as cancer in the long run.

Exposure to UV rays causes certain skin cells to produce the pigment melanin, which darkens through oxidation. Over exposure causes those cells to migrate closer to the skin’s surface and produce more melanin, further darkening the skin into a suntan. It’s no wonder then our bodies are equipped to produce melanin.

Melanin absorbs UV radiation and defends against further penetration of skin tissue. In other animals it proves diversely useful. It absorbs heat, an essential for cold-blooded creatures. It colours bird feathers, fish scales and squid ink, and helps to conceal nocturnal animals. Melanin even absorbs scattered light inside the eye to sharpen vision.

But it appears that only humans will risk their skins for a little extra skin pigment!

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