Sunlight contains ultra violet rays. UV radiation is a part of the electromagnetic spectrum with wavelength shorter than the visible light. It is therefore invisible to human eyes. The UV wavelengths are further classified as UVA, UVB or UVC with UVA with longest wavelength and UVC the shortest. UVC being very short rays are absorbed by the Ozone layer. Both UVA and UVB penetrate the atmosphere and reach the earth.
Though sunlight is essential for the natural production of vitamin D in our body, too much sun can have ill effects on the body. UVB is the major cause of skin reddening and sunburn. UVA penetrates the skin more deeply than UVB and is the major cause of skin aging and wrinkling. UVA damages skin cells found deep inside the layer of epidermis where most skin cancer occurs. It may cause suppression of immune systems too. Both UVA and UVB may play a key role in the development of skin cancer.
In order to protect oneself from these harmful UVA and UVB rays, sunscreen lotions could be used. They form a thin, protective layer on the surface of the skin and absorb or block the UV radiation before it penetrates the skin. They consist of lot of chemicals that can absorb or filter the UV rays. The chemicals are a mixture of organic and inorganic compounds. The organic compounds absorb most of the UV rays and the inorganic ones block the sun’s rays.
The inorganic chemicals that act as blockers are zinc oxide and titanium oxide. They form a physical barrier reflecting or scattering UV waves. The organic components include aminobenzoic acid, dioxybenzone and many more. They absorb UV rays and release their energy as heat.
Sunscreens are definitely not the best solution as they contain many chemical elements. Health organizations often recommend the use of hat and sunglasses to protect the skin.