What happens when we tan and why apply sunscreen ?

What happens when we tan and why should we apply sunscreen ?  Many people invest a great deal of time, effort and money into achieving the perfect suntan, but it is important to understand the physiological process of tanning and what is actually happening to our skin as it changes colour.

The sun emits three types of ultraviolet rays.  These are UVA, UVB and UVC.  The UVC rays are stopped form entering the atmosphere by the ozone layer, and so are not relevant to the tanning process.  Some, but not all, of the UVB rays are stopped by the ozone layer, so these do play a part in the process.  When considering how we get tanned, it is therefore the UVB and (mostly) UVA rays that are relevant.

Ultraviolet rays are not all the same.  UVB and UVA rays differ in terms of the length of their wavelengths, meaning that the rays penetrate to different levels of our skin.  The UVB rays have a shorter wavelength, and mostly affect the epidermis (the upper layer of the skin).  UVA wavelengths are longer, and can reach the dermis (the middle skin layer)

UVA rays cause of skin to change colour because they affect the skin pigment (melanin).  The melanin is oxidised by the UVA rays, which sets off a chemical process that makes the skin darken. UVB rays act differently.  They increase the actual production of melanin in our skin, and also affect the cells in our skin where the melanin is stored.  This also causes the skin to become tanned.

Both UVA and UVB rays, however you are exposed to them, carry risks.  Being vigilant about the proper application of sunscreen is the best possible way to protect your skin form any lasting damage.  Using a BackBliss to apply tanning lotion application to your back will ensure that this rather hard to reach area is well protected at all times.

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