The photo above was taken last year, when I was sunburnt after playing under the sun for a few hours. The difference between my original skin colour and the tanned skin colour is obvious in this photo.
This photo shows how your skin will look like if it peels, but, it is NOT my hand! It's just a photo I found online.
Sunburn is a burn to living tissue such as skin, produced by overexposure to ultraviolet radiation, commonly from the sun's rays. Exposure of the skin to lesser amounts of UV will often produce a suntan. Usual mild symptoms in humans and animals are red or reddish skin that is hot to the touch, general fatigue, and mild dizziness.
UV rays contain UV-A and UV-B rays.
UV-A rays penetrate into the deeper skin layers and damages the site where new skin cells are born, long term exposure to UV-A rays will result in wrinkles, age spots and sagging skin, whereas UV-B rays only affect the surface skin layer. The skin responds by releasing chemicals that dilate blood vessels. This causes fluid leakage and inflammation, which is better known as sunburn.
Suntan
UV-A rays radiate deep into the dermis layer, but has lower energy than UV-B rays. Both the epidermal and the dermal layers contain melanin cells which give us our skin tone, depending on their concentration level. UV rays cause a chemical reaction to the melanin cells, which then lead to rapid melanin cell multiplication. Because UV-A rays penetrate both layers of melanin cells the multiplication of melanin cells in two layers produces a dark tone very quickly.
Sunburn
UV-B rays do not penetrate as deep as the UV-A rays. They penetrate only up to the epidermal layer, and therefore will cause only the epidermal layer's melanin cells to multiply. So, the skin won't tan as fast as if exposed to the UV-A rays. However, UV-B rays have much higher energy than UV-A rays, and because of this, it burns. The energy of the UV-B rays do not deplete as fast as compared to the energy of UV-A rays, and will accumulate on the skin, so it will burn the skin for some time, for up to a few days after a few hours of exposure to the sun.
People who love suntanning do not get sunburned because they apply a suntanning cream, which contains anti-UV-B agents, blocking off the UV-B rays, only allowing UV-A rays to pass through the skin, resulting in a tan.
Funfact!
Sunburn is a condition that not only affects humans, even plants get sunburnt! The photo below shows a sunburnt treetrunk, the left side of the trunk has fallen off due to excessive sun damage.
- daphne (02)