As there is a sun
The color is tan human skin gives a coloring substance melanin, produced by the body as protection against ultraviolet radiation. Melanin is formed each person, except maybe albinos. But much depends on belong to the human race. Fair-skinned people melaminovye cells are quite small and have low density. The increase in both parameters makes the skin darker. We can say that Africans melanin is produced in 2 times more than for example Scandinavians.
Dark-skinned people planning a long stay in the sun, it is imperative to use sunscreen.
Dark skin also tans
However, the assertion that black people are better protected from harmful solar radiation and thus absolutely no risk of skin cancer, is fundamentally wrong. Purely visually, the difference between tanned and untanned blacks may not be so noticeable. Moreover, only a small part of the population of African descent can boast a completely black skin color. In the bulk of the color type they varies from dark brown to shade "coffee with milk". And if the European and the African will hold the same amount of time under the sun, the first time to very severe burns while the second will only be a semitone darker. That is get a tan.
However, for black people the sun can be even more dangerous than their light-skinned counterparts. On the one hand, they too have light skin, able to burn without protection. First of all we are talking about feet and hands. Secondly, it is the dark skin color gives you time to recognize a sudden melanoma. If the white man saw this education, immediately go to the doctor, a dark-skinned miss precious time simply because they don't even know is seriously ill, and continues to be exposed to deadly radiation.
Negros are 10 times less likely to develop cancer of the skin, but the percentage of deaths among representatives of this race are disproportionately large.
Dark skin can also burn
Therefore, we can say that blacks not only sunbathing, but quite a able to burn or even cancer of the skin. That is, dark skin is not an absolute protection from harmful effects of sun rays.
Advice 2: How did the human race
The theory of policentrismo
Polycentricity of the opinion that the origin of the human races depends only on their ancestors at the genetic level. In the process of formation they are not depended from each other and originated from different ancestors from different places from the point of view of the geographical location. In other words, on different continents have evolved parallel to Homo sapiens.
Thus, on the territory of modern Europe gradually formed Caucasian ethnicity, Asia - Mongoloid, Australia - the controversial Australoid, and in Africa - Negroid. Some scientists do not recognize the Australoid race as a separate large, connecting it with the Negroid in the Australian and Negroid.
The weakness of this theory is that the production of pure race, from this point of view, is seen only in theory. In practice, there was a border territory, where members of different races interbred, creating the so-called small races. For example, Ethiopian small race is the result of combining representatives of the Negroid and Caucasoid races. Between Caucasoid and Mongoloid are two small race - Ural and South Siberian.
The theory of monozentrischen
Scientists who call themselves monocentricity, consider that the emergence of the human races was originally the result of common descent, and then separation by skin color and other external factors. They substantiate their theory is much more recent divergence of humankind into races than its origin.
On the theory of policentrismo, monocentricity has much more evidence, of which the first is the acquisition of the main features of Homo sapiens over many centuries before the divergence into races. The evidence can be attributed to the denial of full genetic isolation, so as to consider it impossible crossing in the border areas, as well as of the conquerors with the vanquished, is utopian. There is a third proof, not least, it is common to all races the downward trend in the total mass of the skeleton and of fast development.
Thanks to modern science, appeared a new proof of the theory of monocentrism based on data from the DNA study of the various races. Nevertheless, debate between supporters of the two hypotheses did not subside until now. Scientists in every scientific faction present their evidence of the origin of human races.
Advice 3: Is it good to tan?
The benefits of the sun
The sun gives light and life. It is necessary for plants and for animals and for people. With it produces vitamin D. enjoy the sun much more interesting than to take fish oil, which it replaces. The sun's rays help the body better cope with diseases. They contribute to the strengthening of tooth enamel and bone tissue.
Because of the action of ultraviolet rays is lowered cholesterol levels, reducing blood viscosity, the destruction of harmful bacteria and viruses and enhancing tissue respiration, restore metabolic processes. It also promotes the synthesis of protein, different enzymes and hormones.
Do I need a tan?
Not to say that tanning is harmful or helpful. It signals that the person for some time was in the sun. The sun promotes the production of melanin. Melanin protects the skin from burns and gives it color. When tanning, this means that being in the sun was short-lived. But if it is strong, then the norm of sunlight is exceeded. Solar radiation in high doses can be dangerous. Burns and sunstroke is not so terrible, but can occur and grow different serious illness.
What time to sunbathe?
Do it in the morning or evening. In the daytime the rays of the sun aggressive, and the air is too humid, so it is possible for deep penetration of the rays into the skin. This causes rapid aging. At this time, be sure to hide the umbrella.
How to safeguard yourself?
Sweat protects the skin. It contains rocanova acid. It absorbs ultraviolet radiation. The skin is very sensitive, when the wind blows, and when you exit the water. Try not to sunbathe.
After a long day of sunbathing the skin needs to be cool and moisture. The redness tells about the sun burn. But if it was not, still use creams, lotions and masks, which allow you to cope with minor injuries. Also, use sour cream, kefir and yogurt.
It is important that you have not used the tools that lead to blockage of the skin and increased blood flow.
Advice 4: Is it possible to sunbathe pregnant
Useful if tanning during pregnancy?
According to experts, tanning under certain rules will be useful for the expectant mother and the child developing in her womb. The fact is that while staying under the sunlight in the female body aktiviziruyutsya production of vitamin D3, stimulates the absorption of calcium. A tan obtained in the early stages of pregnancy has a beneficial effect on the process of laying the foetus of all the vital organs and systems contributes to the proper formation of the skeleton.
For the pregnant woman sunbathing will be the harmless way to combat hair loss, damage the teeth and nails. The deterioration of their condition usually associated with lack of vitamin D3 and calcium, but few know that even when you receive of multivitamin complexes, they are not digested fully. But if you combine their intake with a stay in the sun, a useful effect will only increase.
How dangerous tanning during pregnancy?
During pregnancy the female body is most vulnerable, so prolonged sun exposure can lead to deterioration of health of the expectant mother and the developing baby. For example, overheating of the mother increases the temperature of its internal organs and is transmitted to the fetal body which is not able to regulate the temperature of your own body. Therefore, taking sun baths, you should avoid overheating, because it is dangerous disorders of the nervous system and brain of the fetus.
Taking the decision to tan while pregnant, you should take into account the fact that the ultraviolet rays stimulate all the natural processes in the body. If a woman before pregnancy had heart problems, circulation or breathing, prolonged exposure in the sun or in the Solarium, for it can be dangerous.
To sunbathe or not?
In the absence of health problems to sunbathe pregnant is possible and necessary, but only it is necessary to strictly adhere to certain rules related to sun exposure "in position". First, you should not sunbathe from 10 to 16 hours, because at that time the UV rays are most dangerous. It is not recommended to stay on the beach without a hat. If you pick a bright wide-brimmed hat, it will provide head protection from overheating, as the skin from age spots. To not have to squint in the sun, causing the appearance of wrinkles, it is useful to have sunglasses.
If you are planning a trip to the sea, you should discuss with your obstetrician the issue of fluid intake. The expert should explain, how many it is necessary to drink in order to prevent dehydration. It is also advisable to stock up on sunscreen with a high SPF level. Apply on the body they need in 20 minutes before going to the beach and after each bath.
Advice 5: How much you need to sunbathe in the Solarium
Determine the type of skin
The time of tanning is determined mainly by the type of your skin. The first type is Celtic, with very fair skin, blonde or red hair, often with freckles. such people practically do not tan in the sun their skin turns red and burns quickly. Representatives of the Celtic type, it is better not to go to the Solarium, but prefer a bronzer.
The second type is a Nordic - also has fair skin and light brown hair. This type of skin during the sun first turns red and then darkens. Nordic type should also be careful with the sun and start the tanning sessions in the Solarium 2-3 minutes, increasing the time to 10.
The third type is middle Eastern, the most common in Russia. Middle Eastern skin can be light or dark, and her hair from brown to chestnut. This type is tanned, but significant results will take a long time. It is recommended to start tanning with 5 minutes and increase to 15.
The fourth type, the Mediterranean, has dark skin and dark hair, he tans very well and almost never burns. Fourth type you can start a session with 5-7 minutes and increase up to 20.
The fifth type is called the Indonesian, his representatives very dark skin and dark hair. This type of skin almost never occurs in Russia. Basically, he doesn't need more tan, but you can walk a bit in the Solarium to recharge the vitamin D emitted from the ultraviolet light. Best time of the session - 5-10 minutes.
Solarium not only gives the skin a beautiful shade, but also contributes to the treatment of certain skin diseases.
Follow the rules of tanning
No matter how much time you can sunbathe between the first and second session must be at least 48 hours. During this time the skin gets used to the strange effects of UV light, and you will see that you have correctly identified your type. To achieve the desired result, you need to have a course of tanning sessions within 3-4 weeks. Soak 2-3 times a week, gradually increasing time by 1-2 minutes to the maximum recommended values. To maintain the tan go to the tanning salon once in a week and a half.
It is not recommended to combine natural sun tanning and tanning sessions.
Use of the Solarium is necessary to protect the skin, eyes and hair. Girls also need to protect the nipple area - there are special stickers-stikine. Hair put on disposable shower cap and eye - glasses. For the body use the cream for tanning - he's different from the usual cream with UV-filters. Cream for tanning can be a warming - up for a more intense tan with bronzers to give the skin a dark shade, with Golden sequins for Golden sun, cooling for skin prone to burns. Typically, these additional funds are sold at the tanning salon.