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Ultraviolet radiation - the ABCs

Energy from the sun sustains all life on earth, and small amounts of Ultraviolet (UV) radiation are beneficial for people and essential to the production of vitamin D in the body. However, prolonged human exposure to solar radiation can result in acute (short-term) and chronic (long-term) health effects on the skin, eyes and immune system.

Acute effects of excessive UV radiation are sunburn and suntan. This exposure can lead to premature skin ageing and wrinkles. Chronic effects can include skin cancers and cataracts - a permanent clouding of the eye which reduces vision.

We can't see ultraviolet or "UV" rays, as this form of sun energy is invisible. There are three types of ultraviolet radiation: UVA, UVB and UVC.

UVA radiation is the least energetic form. It can cause skin aging and wrinkles, and can also damage outdoor plastics and paint. UVB, which is stronger than UVA, is the most harmful to us and other life forms. It can cause skin cancer and cataracts. Both UVB and UVA can cause suntans and sunburns. UVB also reduces the growth of plants, and may affect the health of wildlife and other animals.

UVC, which is even stronger than UVB, never reaches the earth's surface because it is filtered out by the atmosphere.

Fortunately, there are simple ways to protect yourself from UVB. Most actions you take to protect yourself from UVB will also safeguard you against UVA.