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 Source: http://www.irishhealth.com/index.html?level=4&id=4066
What sunburn does to your skin... You may think it perverse of me to write about suntans considering the state of the Irish weather. So far this has been one of the worst summers we have had to endure for many years. We have been inflicted with frequent bouts of heavy rain and the average daily temperature has been well below the norm for this time of year. Many of our gardens look unusually dull because our garden plants have not basked in the rays of sunshine that are necessary to make them bloom. Most days have been cloudy and dull and it really has required a conscious effort on all our parts to keep our spirits up. However, even though the weather has been bad many Irish people will be exposed to the effects of the sun as record numbers of people flee the emerald isle in pursuit of sunnier climes.
A fashion statement Many people will return from their foreign holidays sporting a suntan, which they have deliberately sought. The suntan has often been regarded as a fashion statement or a mark of affluence. Before the advent of mass travel a suntan was like an expensive designer label that stated: "I’ve got a few bob, I can afford to travel and this suntan proves it". Today some people even speak of a healthy tan. But given what we know about the effects of the sun on our skin maybe we should revisit such views. 'UV radiation is the most important environmental factor in the development of skin cancer, including melanoma, which is one of the most lethal of all cancers.' A suntan is produced by a skin pigment called melanin, which is manufactured by a special type of skin cell called a melanocyte. Melanocytes are located in the epidermis, which is the outermost layer of the skin. When the skin is exposed to UV (ultraviolet) radiation from the sun the melanocytes are stimulated to produce melanin, which migrates to the surface and darkens the skin. Skin type A person’s skin type is a crucial determinant of whether or not they will tan. Skin type is defined on the basis of a six-part classification with skin type 1 being the most sensitive and skin type 6 being the least sensitive. Table 1 describes the characteristics of the various skin types. Skin types 1 and 2 are the predominant skin types in Celtic people, which means that for many Irish people no amount of baking in the sun will produce a tan. Table 1 Type 1 Very sensitive. Always burns. Never tans. Type 2 Minimal tanning but burns easily Type 3 Tans gradually and burns moderately Type 4 Always tans well and burns minimally. Type 5 Tans profusely and rarely burns Type 6 Least sensitive. Rarely burns. Tans profusely. Dermatologists maintain that there is no such thing as a healthy tan. If you have skin type 1 to 4, tanning does not sufficiently protect your skin from burning. It has been estimated in such cases that tanning provides no more protection for the skin than a very low factor sunscreen, which means very little protection at all. Even a light tan is a sign that your skin has been exposed to too much sun. Tanning is considered to be a response to injury because it appears after the UV radiation from the sun has destroyed some cells and injured others. UV radiation also gradually destroys the elastin and collagen fibres in the skin giving the skin a dry, wrinkled and aged look. UV radiation is the most important environmental factor in the development of skin cancer, including melanoma, which is one of the most lethal of all cancers. It can also give rise to lip cancer. UV radiation also affects the eyes and can be an important contributory factor in cataract formation. Rays UV rays are invisible. For descriptive purposes they are divided into three types, UVA, UVB and UVC. UVA rays are the most abundant of the three on the earth’s surface. They are capable of penetrating the skin below the epidermis and can reach the dermis resulting in changes to the fibres in that layer. UVA rays do not burn the skin but can cause skin cancer. These are the type of rays that are produced by sunbeds. Most of the UVB rays from the sun are screened out by the ozone layer but it is likely that more of these rays will reach the earth’s surface if reports about holes in the ozone layer are to be believed. UVB rays can burn the skin resulting in redness and blistering. Long-term exposure to UVB rays and frequent sunburn are associated with melanoma. UVC rays are known to cause cancer but none of them reach the earth’s surface because of the protection from the ozone layer however, that could change in the future because of the aforementioned damage to the layer of ozone. UVC can be produced artificially by arc welding lamps and are known to be very damaging to the skin. Hot spots The level of UV radiation increases the closer you approach the equator because that is the closest point on the earth’s surface to the sun. The level of radiation is also higher at high altitude because there is less protection from the atmosphere the higher you ascend. Therefore skiers, mountain climbers and mountain trekkers need to be very careful about protecting their skin from being exposed to too much sun. It is possible to protect the skin from UV radiation through the use of clothing, hats and sunscreens. Sunscreens work by absorbing, reflecting or dispersing the sun’s rays. Some work by absorbing the rays through a chemical reaction within the skin. These products contain chemicals such as methoxycinnamate and oxybenzone. Other sunscreens physically block the UV rays and reflect them away from the skin. Many of these products contain titanium dioxide. These products tend to give the skin a whitish colour after application but there are newer forms that are practically invisible. Some of them are even tinted to give a tanned appearance to the skin. Dermatologists generally recommend a sunscreen with an SPF (sun protection factor) greater than 15. A SPF of 15 means that the sunscreen offers fifteen times greater protection than the skin’s natural level of protection. The frequency of application of the sunscreen depends on your skin type. For example a person with skin type 1 might need to apply the sunscreen every one to two hours whereas a person with less sensitive skin might only need to apply it every two to three hours. It is important to realise that sunscreens have a short shelf life once opened therefore it is probably best to throw out any remaining sunscreen from last year. In other words buy a new sunscreen every year. Sunbed dangers Sunbeds have become very popular in recent years and many people choose to use sunbeds prior to going on a sun holiday in the mistaken belief that a sunbed-induced tan offers them protection against being burned. It is estimated that a sunbed-induced tan only offers protection to the level of a SPF 2 sunscreen. Therefore people who use sunbeds need additional sun protection when exposed to natural sunlight. As previously stated sunbeds emit UVA rays and natural sunlight consists of a mixture of UVA and UVB. A person who has used a sunbed is still exposed to the risk of being burned by UVB to the same extent as the person who did not use sunbeds at all. Having a sunbed induced tan can create a false sense of security. So you need to use sunscreens even if you have had a number of sessions on the sunbed prior to your sun holiday. It is important to emphasise that clouds do not offer protection against UV radiation. It is estimated that 85% of the sun’s UV radiation penetrates the clouds and reaches the earth’ surface. Therefore protection from the sun is an issue for all the year round and not just the summer. We need to re-think our views about suntans. Maybe we should be thinking that a healthy tan is one you apply from a bottle and not one you acquire by deliberately exposing your skin to radiation. |
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By: Aiste (Registered) on 11-06-2007 09:01