The good news is that life requires the existence of sunlight. The only snag with that is that sunlight just happens to be damaging to your skin. The ultra violet portions of the sun’s spectrum have the right kind of radiation to damage cells. There are actually two quite dinsticts ways in which sunlight can damage you, by genetic and cooking it. When you sunbathe what you do is cook your skin.
If you are pale skinned and daft enough to sunbathe for many minutes without protection, you will see that your skin goes red, then may blister, and may even fall of. These are all simple effects of solar energy heating up the cells of your skin and killing them. However, those effects are not long lasting and not really serious. The other type of damage is potentially far more dangerous. Sunlight can cause damage to the genetic material the DNA of cells without actually killing them. Cells that have been damaged in this way may later go seriously wrong when they divide and reproduce. In fact, one of the most severe types of problems is that cells damaged in this way may produce cancers. The vast majority of them are of two types the squamous cancers and the basal cell cancers neither of which ever spread to areas outside skin, and are therefore not a threat to life. The third kind of skin cancer melanoma is much rarer, but, has the potential for spreading to distant areas of the body. Fortunately, human skin contains its own protectant against sun damage, a brownish pigment called melanin.
Melanin is nature’s sunblock. It is wonderful and serviceable pigment producet in the lower layers of the skin cells called melanocytes. They produce the melanin, which is then taken up by the ordinary skin cells, which hold on it. When the skin is exposed to lots of sunlight, the body accelerates the production of melanin by stimulation of a hormone called melatonin. When there is little sunlight, the body downsizes its melanin production and you and up looking pasty and white as if you lived in a cellar which
As it happens, the skin can produce extra melanin in two ways. It can increase amount of melanin so that white skin steadly becomes more beige, and it can produce little splodges and blobs of melanin, which we call freckles, beauty spots, or moles.