Sun tanning or just tanning is a process in which skin tones become dark or tanned. This is most often the result of exposure to ultraviolet (UV) radiation from sunlight or from artificial sources, such as tanning lamps found in indoor tanning beds. People who deliberately disguise their skin with sun exposure are involved in a passive recreational activity sun bath . Some people use chemical products that can produce tanning effects without exposure to ultraviolet radiation, known as sunless tanning.
Moderate exposure to sunlight contributes to the production of melanin and vitamin D by the body, but excessive exposure to ultraviolet light has a negative health effect, including sunburn and an increased risk of skin cancer, as well as immune system function that is suppressed and accelerated aging. skin. Some people sunbathe or sunburn more easily than others. This may be the result of different skin types and natural skin tones, and this may be the result of genetics.
Some cases of tanning addiction have been reported by medical researchers. Although the mechanism by which tanning addiction occurs is unknown, some evidence suggests that the release of endorphins during the tanning process causes an unpleasant effect that underlies addiction.
The term "tanning" has a cultural origin, arising from the color of chocolate. Its origins lie in Western European culture when it becomes fashionable for young women to look for pale skin (see Cultural history below).
Video Sun tanning
Tannery
Melanin is a natural pigment produced by a cell called melanocytes in a process called melanogenesis. Melanocytes produce two types of melanin: pheomelanin (red) and eumelanin (very dark brown). Melanin protects the body by absorbing ultraviolet radiation. Excessive ultraviolet radiation causes the skin to burn along with other direct and indirect DNA damage to the skin, and the body naturally battles and tries to repair the damage and protect the skin by creating and releasing further melanin into skin cells. With melanin production, skin tones become dark. The tanning process can be triggered by natural sunlight or by artificial UV radiation, which can be transmitted in UVA, UVB, or a combination of both. Intensity is generally measured by the UV Index.
There are two different mechanisms involved in tan production by UV exposure: First, UVA radiation creates oxidative stress, which in turn oxidizes the existing melanin and causes rapid melanin meltdown. UVA can also cause melanin to be redistributed (released from melanocytes where it has been deposited), but the total number has not changed. Dark skin from UVA exposure does not result in a significant increase in melanin production or protection against sunburn.
In the second process, mainly triggered by UVB, there is an increased production of melanin (melanogenesis), which is the body's reaction to direct the photodamage of DNA (the formation of pyrimidine dimers) of UV radiation. Melanogenesis causes delayed tanning, and usually becomes visible two or three days after exposure. Plants created by increased melanogenesis typically last for weeks or months, much longer than tan caused by the existing melanin oxidation, and also actually protect against UV skin damage and sunlight, not just cosmetics. Usually, this can provide a simple Sun Protection Factor (SPF) of 3, which means that the tan will tolerate up to 3 times the exposure of UV rays as pale skin. However, to cause true melanogenesis-tanning by way of UV exposure, some direct DNA photodamage must first be produced, and this requires UVB exposure (as it is present in natural sunlight, or sunlamps that produce UVB).
The ultraviolet frequencies responsible for tanning are often divided into UVA and UVB ranges.
UVA
Ultraviolet A (UVA) radiation is in the wavelength range 320 to 400Ã, nm. It comes more uniform throughout the day, and throughout the year, from UVB. Most UVAs are not blocked by the atmospheric ozone layer. UVA causes the release of existing melanin from melanocytes to join oxygen (oxidized) to create the true tan color in the skin.
UVA is blocked less than UVB by many sunscreens, but is blocked to some degree by clothing. UVA is well known for causing DNA damage and becomes carcinogenic. However, it operates not by inducing direct DNA damage, but by producing reactive oxygen species that damage DNA indirectly. UVA (see above) induces skin brown but little extra melanin protection against sun damage, sunburn, or cancer.
UVB
Ultraviolet B (UVB) radiation is in the 280 to 320 nm wavelength range. Most of these bands are blocked by Earth's ozone layer, but some penetrate. UVB:
- triggers the destruction of CPD-DNA (direct DNA damage), which in turn induces increased melanin production.
- is more likely to cause sunburn than UVA as a result of excessive exposure. The mechanisms for sunburn and increased melanogenesis are identical. Both are caused by direct DNA damage (CPD formation).
- produces Vitamin D on human skin.
- is reduced by almost all sunscreens according to their SPF.
- is considered, but not proven, causes the formation of moles and some types of skin cancer.
- causes skin aging (but at a slower rate than UVA).
- stimulates new melanin production, which leads to increased dark-colored pigments within days.
Maps Sun tanning
Different skin tanning behavior
A person's natural skin color affects his reaction to sun exposure. The natural skin color of a person can vary from dark brown to almost colorless pigmentation, which may appear white. In 1975, Harvard physician Thomas B. Fitzpatrick composed the Fitzpatrick scale describing the general tanning behavior of various skin types, as follows:
Health aspects
The most common risk of exposure to ultraviolet radiation is sunburn, speed and severity varying between individuals. This can be reduced to at least to some extent by previous applications of appropriate sunscreen strength, which will also inhibit the tanning process due to UV blocking.
Overexposure to ultraviolet radiation is known to cause skin cancer, making skin aging and wrinkles faster, DNA mutations, and damage the immune system. Often using tanning beds triples the risk of developing melanoma, the deadliest form of skin cancer, according to a 2010 study. This study shows that the associated melanoma risk is closer to total exposure than the age at which an individual first uses a tanning bed. The International Agency for Research on Cancer places the use of tanning beds in the highest cancer risk category, describing them as carcinogenic to humans even if used as recommended.
Some organizations, such as the World Health Organization (WHO), the American Cancer Society, and the US Surgeon General have issued warning guidelines on sun tanning and UV radiation exposure, either from the sun or from indoor tanning.
Vitamin D production is very important for human health. Medium exposure (avoiding sunlight) to UV radiation provides benefits such as increased vitamin D, as well as other benefits that may still be studied.
Some tanning activists have used various forms of psoralen, known as fotokarsinogenik. Health authorities have banned psoralen since July 1996.
Cultural history
Tanning is in and out of fashion. In the United States and Western Europe before about the 1920s, tanned skin was associated with lower classes, because they worked out and exposed to the sun. Women strive to maintain pale skin, as a sign of their "refinement".
Women's outerwear styles are designed to protect against sun exposure, with long arms, and sunbonnets and other large hats, veils, and umbrellas protecting the head. Women even go so far as to put lead-based cosmetics on their skin to whiten artificially the color of their skin. However, when not closely monitored, these cosmetics lead to lead poisoning. The light-skinned appearance is achieved by other means, including the use of arsenic to whiten the skin, and brighten the powder. The preference for fair skin continues until the end of the Victorian era.
At the beginning of the 20th century, therapeutic benefits of sunlight began to be recognized. In 1903, Niels Finsen was awarded the Nobel Prize in Medicine for his "Finsen Light Therapy". The therapy is a cure for diseases such as lupus vulgaris and rickets. Vitamin D deficiency is found to be the cause of rickets, and sun exposure will allow vitamin D to be produced in a person. Therefore, exposure to sunlight is a cure for some diseases, especially rickets. In 1910 a scientific expedition went to the island of Tenerife to test the broader health benefits of "heliotherapy", and in 1913 "sunbathing" was referred to as a desirable activity for a hasty class.
Shortly after, in the 1920s, fashion designer Coco Chanel was accidentally exposed to the sun when visiting the French Riviera. When he arrived home, he arrived with sunscreen and his fans apparently liked the look and began to adopt darker skin tones. Tanned skin is becoming a trend partly due to Coco's status and lifestyle longings by other community members. In addition, Parisians fell in love with Josephine Baker, a "caramel-skinned" singer in Paris, and idolized his dark skin. These two women are the main characters of transformation whose brown skin experiences, in which it becomes regarded as fashionable, healthy, and luxurious. Jean Patou utilized a new tanning mode, launching the first sun tan tan "Huile de Chaldee" in 1927.
Just before the 1930s, solar therapy became a popular remedy for almost every disease from simple fatigue to tuberculosis. In the 1940s, ads began to appear in women's magazines that encouraged sun bathing. At the same time, the coverage of leather swimwear began to decline, with the bikini changing the style of the swimsuit radically after its appearance made in 1946. In the 1950s, many people used baby oil as a method to improve tanning. Self-tanner first appeared in the same decade and is known as "Man-Tan," although it often causes unwanted orange skin. Coppertone, in 1953, marketed a sunscreen with the image of a little blond girl and her spaniel cocker tugging at her swimsuit showing the bottom and brown line; this ad was modified around the turn of the 21st century and now shows a little girl wearing a one-piece swimsuit or shorts. In the latter part of the 1950s, silver metal reflectors were common to enhance brown color.
In 1962, sunscreens began to be assessed by SPF, although SPF labeling in the US was not standardized by the FDA until 1978. In 1971, Mattel introduced Malibu Barbie, who had disguised his leather, sunglasses, and sun-tanning lotion bottles. In 1978, two sunscreens with an SPF 15 rating as well as the first tanning bed appeared. In 2007, there were about 50,000 outlets for indoor tanning; it is a five billion dollar industry in the United States, and has spawned additional industries for indoor tanning lotions including bronzers, intensifiers, and accelerators. Since then, the indoor tanning industry has become more restricted by health regulations. In China, darker skin is still regarded by many as a mark of the lower classes. Recently in 2012, in parts of China, ski masks became popular items to wear on the beach to protect the wearer's face from the effects of the sun.
Many people consider the tan line to be seen as not as aesthetic, and try to avoid the brown lines that will be visible when the clothes are used. Some people try to achieve whole brown skin or to maximize their tan coverage. To achieve a thorough chocolate, tanners need to minimize the amount of clothing they wear during tanning. For women who can not dispose of bathing suits, they occasionally bask in the back ropes when lying in front, or take off the shoulder straps, in addition to wearing swimsuits that cover fewer areas than their normal clothes. Every exposure is subject to local community standards and personal preferences. Some people bask in the privacy of their backyards where they can sometimes tan without clothes, and some countries have set aside an optional swimming swim area (popularly known as a nude beach), where people can sunbathe and swim free-clothes. Some people tan topless, and others wear very short swimwear, such as microkini or thong.
The 1969 innovation is a tan-through swimsuit, which uses hollow fabrics with thousands of micro holes that are barely visible to the naked eye, but that sends enough sunlight to get close to all the chocolate, especially if the fabric is pulled tight. Tan-through swimsuits typically allow over a third of UV light to pass through (equivalent to SPF 3 or less), and sunscreen applications even to enclosed areas are recommended.
Sunless tanning
To avoid exposure to UVB and UVA rays, or in the sunless, strong seasons, some people take alternative measures to come up with dark skin. They may use sunless tanning (also known as self-tanners); stainers based on dihydroxyacetone (DHA); or cosmetics such as bronzer. Others can make a tanned appearance by wearing brown stockings or pantyhose.
Many non-sun tanning products are available in the form of dark creams, gels, lotions, and sprays applied on the skin. There are also professional tanning booth tanning options offered by spas, salons, and leather tanning businesses. Spray tanning does not involve color sprayed on the body, but uses a colorless chemical that reacts with proteins in the upper layers of the skin, producing a brown color.
See also
- Freckles
- Slip-Slop-Slap
References
External links
- Shoot the Melanoma
- Tanning information from The Skin Cancer Foundation
- Research on UV exposure benefits
Source of the article : Wikipedia
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