The sun’s ultraviolet (UV) radiation is the best natural source of vitamin D. However, too much UV exposure from the sun and other sources, such as solariums , is major cause of sunburn, premature ageing, eye damage and skin damage leading to skin cancer.
UV cannot be seen or felt. It is not like the sun’s light which we see, or the sun’s warmth (infrared radiation) which we feel. Our senses cannot detect UV so it can be damaging without us knowing.
There is a huge variation in UV levels across Australia. The UV level is affected by a number of factors including the time of day, time of year, cloud cover, altitude, proximity to the equator, scattering and reflection.
SunSmart UV Alert
The SunSmart UV Alert, produced by the Bureau of Meteorology , predicts when sun protection is required. It provides daily sun protection times for more than 200 locations across Australia, based on cloud-free skies. It uses the World Health Organization's Global Solar UV Index.
During the sun protection times, the UV radiation is at a level that can damage your skin. If there is no UV Alert, sun protection isn't required unless you are near highly reflective surfaces such as snow, outside for extended periods or the UV is above three.
The UV Alert is available as a free widget for your website , as a free SunSmart app, in the weather section of the Herald Sun, or you can find it on the Bureau of Meteorology and SunSmart websites.
Daily sun protection times
The daily sun protection times are calculated from the UV alert, consisting of the times of the day when the UV is predicted to be 3 or above. When the UV is 3 and above it can be damaging to the skin.
SunSmart recommends using a combination of the five sun protection measures during the daily sun protection times: Slip on clothing , Slop on SPF30 or higher sunscreen , Slap on a hat , Seek shade and Slide on sunnies .
Remember: UV levels are most intense in the middle of the day.
Health effects of too much UV radiation
Overexposure to UV radiation causes skin and eye damage, sunburn, tanning and ultimately can result in skin cancer.
Sunburn occurs when too much UV radiation affects the skin. Skin turns red within two to six hours of being burnt. It will continue to develop for the next 24 to 72 hours. If enough UV exposure has occurred to cause sunburn, the damaged skin may become more sensitive to infrared radiation (heat).
The more exposure to UV radiation, the worse the sunburn becomes. The amount of sun exposure required to cause sunburn varies greatly from person to person. People with very fair, fair and light brown skin tend to be more sensitive to the sun and burn more easily. In summer, a fair-skinned person can burn in as little as 11 minutes. People with darker skin are less sensitive to the sun and may rarely burn.
Sunburn at any age, whether serious or mild, can cause permanent and irreversible skin damage that can lay the groundwork for skin cancer later in life. Your lifetime tally of UV radiation exposure, together with the number of severe sunburns, increases your risk of skin cancer.
Eye damage related to UV exposure 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.
Premature ageing including skin wrinkling, sagging, blotchiness and roughness is caused by exposure to UV radiation.
Photosensitivity is an abnormally high sensitivity of the skin or eyes to UV radiation exposure. The skin can burn more easily increasing your risk of skin cancer.
Photosensitivity is caused by ingesting, inhaling or coming into skin contact with photosensitisers – substances that cause photosensitivity. Photosensitisers include industrial chemicals, drugs, plants and some essential oils and fragrances. Some medications can cause photosensitivity. Check with your doctor or pharmacist, as alternate medication may be available.
Information on substances which cause photosensitivity can be found in the Guidance note for the protection of workers from ultraviolet radiation in sunlight from Safe Work Australia.