Understanding UV radiation
The sun sends out different types of radiation – visible light that we see as sunlight, infrared radiation felt as heat and UV radiation that we can't see or feel.
Are there different types of radiation in sunlight?
Yes. The types of radiation include
• visible light, which gives us the colours we see,
• infrared radiation which gives us the warmth we feel, and • ultraviolet (UV) radiation.
Except in extreme situations, neither visible light nor infrared radiation from sunlight causes health problems. However, ultraviolet (UV) radiation can cause harmful effects to the skin. There are three basic types of ultraviolet radiation:
• UVA (long-wave UV),
• UVB (sunburn UV), and
UVC (short-wave UV)
Types of UV radiation
There are three types of UV radiation, categorised by wavelength: UVA, UVB and UVC. • UVA can cause sunburn, DNA (cell) damage in the skin and skin cancer. • UVB causes skin damage and skin cancer. Ozone stops most UVB from reaching the earth's surface. • UVC is the most dangerous type of UV. Ozone in the atmosphere absorbs all UVC so none reaches the earth's surface. .
Too much ultraviolet (UV) radiation exposure can cause sunburn, premature ageing and skin damage leading to skin cancer. It can also cause eye damage. Too little UV exposure can lead to vitamin D deficiency, which can weaken bones and muscles and affect overall health.
Sunburn is a radiation burn to the skin
Find out the facts about sunburn, the degrees of sunburn and treatment.
Sun-related eye damage includes photoconjunctivitis, which is also known as snow blindness or welders flash, photokeratitis, macular degeneration, cataracts, pterygiums and skin cancer of the conjunctiva and skin surrounding the eye.
Most visible signs of ageing are from skin damage caused by exposure to UV radiation. This can include skin wrinkling, sagging, blotchiness and roughness.
Find out more about the health risks of too little sun and advice about how much sun is enough to maintain adequate vitamin D levels.
When do I need sun protection?
Most Australians need sun protection when the UV Index is 3 or above. At this level, the ultraviolet (UV) radiation is strong enough to damage the skin and eyes. Skin cancer risk is related to the number of severe sunburns, particularly during childhood. A person's lifetime or ‘cumulative' exposure can also put you at high risk of skin cancer. Our research shows that people are more likely to get sunburnt or add to their lifetime exposure tally when: • working outdoors; where a lifetime spent working outside, year after year, can put you at high risk of skin cancer • in the car; if in the car for a long time, you can get sunburnt. Consider using sunscreen and find out about window tinting • playing or watching sport; many summer sports are played during times when there is a UV Alert • around water; our research tells us that most Victorians burn when around water or doing water related activities • attending a summertime outdoor event or festival; many summer events are held at times when UV levels are strong enough to damage the skin and the eyes • at the snow or mountains; UV levels are stronger at higher altitudes and snow is a highly reflective surface catching visitors unprepared.
People in southern states may not need sun protection from May to August when the UV Index is likely to be below 3. The table below is a guide to average peak UV levels by month for Australian capital cities. Shaded areas are months of the year when UV is less than 3 and sun protection may not be needed. Table 1. UV Index in selected Australian cities averaged over the days in each month Location |Jan |Feb |Mar |Apr |May |June |July |Aug |Sept |Oct |Nov |Dec | |Darwin |11 |12 |11 |6 |8 |7 |7 |9 |11 |11 |11 |10 | |Brisbane |11 |10 |9 |6 |4 |3 |3 |5 |7 |8 |10 |11 | |Perth |11 |10...
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