SUNBURN with information from various sources including the Victorian Anti Cancer Council Webpage

Its that time of the year, yet again, when we should be extra careful with sunburn. Sunburn doesn't just mean sore shoulders and legs for a couple of days. It can cause the skin to prematurely age and to become leathery, roughened and blotchy. On top of all that is the real chance of in later life getting skin cancer in one of its many forms. Take heed of the message and Slip, Slop, Slap.

Sunburn comes from overexposure to UV rays, which are made up of 3 components, UVA, UVB and UVC. Now that we are approaching summer it is worth noting that the levels of UVB can be as much as 10 times higher in summer as they are in winter. On top of that the level varies throughout the day with the most dangerous times being between 11am and 3pm. These are the hours when you will burn fastest. You will burn outside these hours, it will just take longer. Some UV reaches you directly from the sun but you have to be careful of reflected UV from sand and snow.

The risks of sunburn are much increased with altitude because the thinner atmosphere filters out less of the suns harmful rays. At an altitude of 2000m, such as on top of many of our higher peaks, the amount of UV can be as much as 20% higher. The level of UV is totally independent of the air temperature.

UV radiation is not only a catalyst for skin cancer; it also suppresses your immune system, an important defence against melanomas and other skin cancers. At present Australia has the highest incidence of skin cancer in the world and around two out of three of us will get some form of it. More than 1200 Australians die each year from skin cancer, 75% with melanoma, the deadliest of the skin cancers. This places a major cost burden of around $234 million per year on the national health system. Melanomas tend to develop along gender lines. In women the most common sites are on the legs, in men it is the upper back.

We can all do our bit to help ourselves by slipping on a shirt, slapping on a hat and slopping on sunscreen. There are two types of screen, the chemical barrier that absorbs part or all of the UV, and the physical barrier such as zinc cream that reflects or scatters the harmful rays. Most people when they apply sunscreen apply it far too sparingly. Don’t rub the sunscreen in vigorously. The instructions on containers all say the screen should be applied liberally, and regularly. Sunscreens that comply with strict tests carry a SPF rating of between SPF4 and SPF 30+. An SPF30+ means at least 31 but can be more. A SPF number is a guide to its relative strength but cannot be used to work out how long it will take someone to burn. Price does not indicate quality. Any cream that has a rating will perform as well as another cream with a similar rating.

Most sunscreens are labelled "broad spectrum" meaning that they will screen out both UVA as well as UVB. Most contain cinnamates, salicylates or dibenzoylmethanes as the active ingredients and water resistant ones usually contain some sort of polymer to bind the screen to the skin. Be aware that most sunscreens have a shelf life of around two to three years and while they conform to a SPF standard their ability to withstand temperature can vary markedly between brands. They should be stored at a temperature of less than 25.

Frequently a sunscreen is applied with an insect repellent as well. Many insect repellents contain DEET that reduces the effectiveness of sunscreens. There are now some brands with a combined sunscreen and repellent. These sunscreens still have to comply with the Australian SPF standard.

UV can also cause problems for the eyes. Wearing of sunglasses is advisable and many are now labelled to show that they block UVR. Approximately 95% UVR block is implied in the Australian sunglasses standard (AS1067); sunglasses that block 100% UVR are ideal. While polarising glasses reduce glare, polarisation in itself has little effect on the UVR absorbing properties of lenses.

As the sun gets that much stronger in the warmer months it is time to take heed and look after oneself.