By getting a tan, the skin defends itself from the sun
For decades, doctors have been struggling against excessive exposure to sunlight. In the recent years there has been a lot of talk about the positive effects of the sunlight from the aspect of synthesizing vitamin D which is necessary for the human organism. Get to know the Sun and its influence before you begin to fry yourself or to frantically run away from it.
Sunlight contains UVA and UVB rays, while the UVC rays are mostly stopped by the ozone layer. After 20 minutes of skin exposure to strong UVA and UVB rays, burns can occur. UVB spectrum is primarily to blame for this effect.
By further exposure, the UV rays change the genetic structure of the skin cells and damage them. The cells defend themselves from the Sun rays by creating melanin, which is a pigment. Our tan is the ability of the skin to adequately defend itself from the harmful influence of the UV radiation on it.
Genetic change in the cells implies that the collagen and elastin in the skin are torn apart, and with long-term exposure, atypical cells appear. The atypical cells are the cells whose change leads to the creation of different carcinomas.
Unfortunately, the sunlight is such that the skin recovers very poorly from it. All of our exposure to this type of radiation during the years is added, and it leads to the early ageing of the skin, its thinning or thickening, wrinkling, and also to the precancerosis and skin carcinoma.
On the other hand, a moderate exposure to the Sun enables the synthesis of vitamin D, has a beneficial effect on one group of inflammatory processes in the skin and enables a good mood. Synthesis of vitamin D stops the moment when sunscreen with a protection factor of 30+ is applied to the skin. This is the reason why 15 minutes of whole body exposure to the Sun without the sunscreen is recommended. After the specified time, protection by sunscreen should be applied.
In the past century, pale white skin signified the aristocratic background. Only the women who worked in the field had a dark tan. In our time, popularity of tanned skin is such that many young people expose themselves to artificial radiation in solariums (tanning beds). The lamps in the tanning beds emit more UVA rays to avoid the noticeable skin burning caused by the UVB radiation. However, UVA rays penetrate deeper into the skin and have a greater potential to change cells genetically and are therefore more dangerous.
It is a fallacy to believe that solariums are preparing us for sunbathing, since the UVB radiation is the main cause of sunburn. There is a justification for solarium exposure only with the persons who are allergic to the Sun, and it should be dosed and controlled.
When we are on the sea or the mountain, sunscreen with a protection factor of 30+ should be applied on the face every 2 hours. It is a way to save the skin of the face from early ageing. When it comes to the body, the rules are similar, and sunbathing between 12 and 17 h is by no means recommended.
The World Health Organization recommends wearing the wardrobe adjusted for skin protection from UV radiation, and cooling at the same time. Hats and UV protection sunglasses are required. It should be known that a canvas umbrella equals a protection factor of 15, which is significantly less then the factor in our sunscreen.
In the last few decades, the statistics of malignant melanomas and other carcinomas of the skin are on a significant rise. The basic risk factor is excessive exposure to radiation from the Sun and lamps in the tanning beds. This is the primary reason behind the constant appeals from the doctors for us to behave adequately and protect ourselves when it comes to the Sun.
Spec. Dr. Svetlana Djurisic, dermatologist
Dermatological clinic DERMATIM, Belgrade, Serbia