Sun tanning

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A woman sunbathing

A suntanned arm showing browner skin where it has been exposed. This pattern of tanning is often called a farmer's tan

Sun tanning describes a darkening of the skin (especially of fair-skinned individuals) in a natural physiological response stimulated by exposure to ultraviolet radiation from sunshine or from artificial sources such as a tanning bed. With excess exposure to ultraviolet, a sunburn can develop.

1 Cause and effect
2 Health benefits
3 Cultural history
- 3.1 Sociological Perspective
4 Dressing for sun tanning
5 Preventing overexposure
6 Tanning and sunscreen
7 See also
8 External links
9 Articles
10 References

[edit] Cause and effect

Two different mechanisms contribute to the UV-induced darkening of the skin. Firstly the UVA-radiation generates oxidative stress which in turn oxidises pre-existing melanin. This leads to rapid darkening of already existing melanin. The second mechanism is the increased production of melanin (melanogenesis).^[1] It is a reaction of the body to photodamage from UVB.^[2] This melanogenesis is triggered by the same DNA damage that causes sunburn. Melanogenesis leads to delayed tanning. It first becomes visible about 72 hours after exposure.^[1] The tan that is created by an increased melanogenesis lasts much longer than the one that is caused by oxidation of existing melanin.

Darkening of the skin is caused by an increased release of the pigment melanin into the skin's cells after exposure to ultraviolet radiation. Melanin is produced by cells called melanocytes and protects the body from direct and indirect DNA damage absorbing an excess of solar radiation, which can be harmful. Depending on genetics, some people can darken quickly and deeply whereas others do not darken much at all.

The ultraviolet frequencies responsible for tanning are often divided into the UVA (315 to 400nm wavelength) and UVB (280 to 315nm wavelength) ranges.

UVB

triggers the formation of CPD-DNA damage (direct DNA damage) which in turn induces an increased melanin production^[2]
is more likely to cause a sunburn than UVA as a result of overexposure. The mechanism for sunburn and increased melanogenesis is identical.^[3] Both are caused by the direct DNA damage (formation of CPDs)
reduced by virtually all sunscreens in accordance with their SPF
is thought to cause the formation of moles and some types of skin cancer (but not melanoma)
causes skin aging (but at a far slower rate than UVA.)
produces Vitamin D in human skin

UVA

causes release of preexisting melanin from the melanocytes
causes the melanin to combine with oxygen (oxidize), which creates the actual tan color in the skin
seems to cause cancer less than UVB, but causes melanoma, a far more dangerous type of skin cancer than other types
is blocked less than UVB by many sunscreens but is blocked to some degree by clothing
is present more uniformly throughout the day, and throughout the seasons than UVB

[edit] Health benefits

The skin produces vitamin D in response to sun exposure (in particular, UVB waves in the 285nm to 287nm range), which can be a health benefit for those with vitamin D deficiency. In 2002, Dr. William B. Grant published an article claiming that 23,800 premature deaths occur in the US annually from cancer due to insufficient UVB exposures (apparently via vitamin D deficiency).^[4] This is higher than 8,800 deaths occurred from melanoma or squamous cell carcinoma. This does not mean that sun tanning is safe or beneficial. Spending several minutes in the sun is long enough to obtain your daily dose of vitamin D. Another research^[5]^[6] estimates that 50,000–63,000 individuals in the United States and 19,000 - 25,000 in the UK die prematurely from cancer annually due to insufficient vitamin D.

However 10 to 15 minutes of sun exposure two times per week will provide adequate vitamin D, while minimizing risks from UV exposure. Further, sun exposure and tanning will not produce vitamin D when the sun is too low in the sky. Relatively smaller amounts of vitamin D can be obtained from fatty fish and other foods. ^[7]

Another effect of vitamin D deficiency is osteomalacia, which can result in bone pain, difficulty in weight bearing and sometimes fractures. This work has been updated in Grant et al. 2005^[8] and Grant and Garland, 2006^[9] In addition, it was reported that in Spain, risk of non-melanoma skin cancer is balanced by reduced risk of 16 types of cancer [Grant, 2006]^[10]

According to a 2007 research of Islam, Gauderman, Cozen, and Mack ^[11] ^[12], sun exposure during childhood prevents multiple sclerosis later in life.

Ultraviolet radiation has other medical applications, in the treatment of skin conditions such as psoriasis and vitiligo. Sunshine is informally used as a short term way to treat or hide acne, but research shows that in the long term, acne worsens with sunlight exposure and safer treatments now exist (see phototherapy).

[edit] Cultural history

Sunbathing Russian girl on the Turkish beach

Throughout history, tanning has seen several fluctuations in popularity. In ancient times the sun played a central religious role in Egyptian, Greek, and Peruvian culture. For Egyptians “Ra” was the sun god, the Greeks had “Apollo,” and the Peruvian ruler was believed to be the sun incarnate. With the introduction of the class system in societies throughout the world, religious beliefs connected to the sun gave way to social distinctions between those of tanned complexion and those without. This class system often separated those deemed to be high class and those who were not. This distinction was physically manifested in the color of one’s skin. Those who often spent long hours in the sun with their laborsome jobs were often grouped together as lower class. A sociology professor at Trent University, Stephen Katz, sums up this point best with his quote, “Tans were labor tans, and not leisure tans like they are today” ^[13].

Women even went as far as to put lead based cosmetics on their skin to artificially augment their appearance ^[14]. However, these cosmetics slowly caused their death through lead poisoning. Achieving this light skinned appearance was brought about in many ways through the aforementioned lead-based cosmetics, use of arsenic to whiten skin, on to more modern methods of full length clothes, powders, and parasols. This fair-skinned trend continued up until the end of the Victorian era. Niels Finsen was awarded the Nobel Prize in medicine in 1903 for his “Finsen Light Therapy” ^[15]. This therapy was to cure infectious diseases such as lupus vulgaris and rickets disease. Vitamin D deficiency was found to be a cause of rickets disease, and exposure to the sun would allow Vitamin D to be produced in a person. Therefore, sun exposure was a remedy to curing several diseases, especially rickets. Shortly thereafter, in the 1920’s, Coco Chanel accidentally got burnt while visiting the French Riviera. Her fans apparently liked the look and started to adopt darker skin tones themselves. Tanned skin became a trend partly because of Coco’s status and the longing for her lifestyle by other members of society. In addition, Parisians fell in love with Josephine Baker, a “caramel-skinned” singer in Paris. Those who liked and idolized her wanted darker skin so they could be more like her. These two French women were two trendsetters of the transformation of tanned skin being viewed as fashionable, healthy, and luxurious ^[16].

Sometimes tanning can be used for comedic purposes

In the 1940’s, women’s magazines started using advertisements that encouraged sun bathing. At this time, tanning oil and bathing suits that left little to the imagination were coming out. The bikini made its appearance in 1946. Louis Reard was the French designer who introduced the bikini. In the 1950’s, an ever-growing trend was to use baby oil as a method to tan more quickly. The first self-tanner came about in the same decade and was known as “Man-Tan,” and often led to undesirable orange skin ^[17]. Coppertone, in 1953, brought out the little blond girl and her cocker spaniel tugging on her bathing suit bottoms on the cover of their sunscreen bottles; this is still the same advertisement they use today on their bottles of sunscreen. In the latter part of the 50’s, silver metallic UV reflectors were common to enhance one’s tan. The “1960’s reveled in the sand-and-surf ethos epitomized by the Beach Boys” ^[18]. Their superstar status helped to promote tanned skin as desirable. In 1971, Mattel introduced Malibu Barbie, “the ultimate beach bunny,” ^[19] with tanned skin, sunglasses, and her very own bottle of sun tanning lotion. The same decade, specifically 1978, gave rise to tanning beds and sunscreen with SPF 15. Today there is an estimated 50,000 outlets for tanning, whereas in the 90’s there were only around 10,000. The tanning business is a five-billion dollar industry, obviously a very profitable industry ^[20].

In some other parts of the world, fair skin remains the standard of beauty. The geisha of Japan were renowned for their brilliant white painted faces, and the appeal of the bihaku (美白, bihaku^?), or "beautiful white", ideal leads many Japanese women to avoid any form of tanning^[21]. There are exceptions to this, of course, with Japanese fashion trends such as ganguro emphasizing almost black skin. The color white is associated with purity and divinity in many Eastern religions. In post-colonial Africa and India, dark skin is heavily associated with a lower class status, and some people resort to skin bleaching to achieve a skin color they view as more socially acceptable.^{[citation needed]}

[edit] Sociological Perspective

Separation of Social Classes

Tanning has seen a marked increase in popularity in recent years. One evidence of this trend has been seen in the growth of skin cancer, outdoor tanning, and tanning salons. The reason for this increase is because of society’s altered definition for the significance of a tan. Having, or not having, a tan has always had a deeper meaning within society. The upper classes have especially changed the meaning of a tan. When the sun was worshipped tanning was popular, but in later years when a tan was associated with the lower class lifestyle it was no longer desirable. The rise and fall in popularity of tanning has less to do with the color of one’s skin and more to do with the means in which the tan was obtained. Tanning again became popular when low class jobs moved indoors and the upper classes had more leisure time to spend outdoors. Tanning was no longer a sign of low class jobs so upper classes embraced the bronzed look. Still today, having a tan is a sign of status and is associated with being a member of the upper classes. Having darker skin is not the only desirable product of tanning, but it is also to show that one is wealthy enough to be able to spend time working on their tan ^[22].

Society’s Concept of Image

Tanning allows for many different perceived images of others and of oneself. Today, tanning is a sign of being healthy, even if that is not remotely accurate. Upon many studies, both men and women view a tanned body as more healthy than a pale body ^[23], even if tanning leads to an unhealthy body by way of skin cancer, blistered skin, burnt skin, freckles, and wrinkles among others. Society, women especially, constantly alter their bodies to conform to society’s expectations whether it be through dieting, eating disorders, cosmetic surgery, or in this case tanning. Though women know the consequences of tanning, they continue to do it. This represents the conflict between one’s health and the social values of being physically attractive. People prefer to appear healthy and conform to society’s expectations, rather than ensure a long, prosperous life by avoiding sun damage ^[24]. In most cases, women do not tan because of how they are going to view their body (though some do), but more so how others are going to view it. A person’s self-identity and self-image are strongly influenced by social constructions. The image one conveys through having bronzed skin is largely responsible for the ever-growing trend of tanning today ^[25].

Society’s Lifestyle of Ease and Quick Gratification

Another reason tanning has been adopted so readily is because it fits in with society’s lifestyle, especially the obsession with instant gratification. The rewards and benefits of tanning are immediate while the risks and negative side effects are delayed and sometimes never experienced. Also, the easy accessibility toward obtaining a tan leads to people continuing the habit, no matter what time of year. With tanning salons open year-round, one can maintain their fresh, summer glow all year long, rather than just for a few months during the summer ^[26]. Due to the fact that there are tanning salons in almost every strip mall and mid-size shopping center, people see tanning salons as acceptable. Similar to Starbucks, the accessibility makes tanning convenient, enjoyable, and accepted by society as a common habit not to be ashamed of.

Status, self-image, and ease of accessibility are important among today’s society. Tanning has become a sign of one’s status among the upper class, of the wealthy, of the healthy, and of those concerned with their appearance ^[27]. In the same manner that a woman wearing diamonds is a sign of wealth, today, being tan is a sign of high social class. People will go to great lengths to achieve the perfect tan, no matter what the costs. So until the day when pale truly becomes the new tan, being tan will be a symbol of one’s status not just the color of their skin.

[edit] Dressing for sun tanning

Women wearing monokinis sunbathing on a beach in Barcelona, Spain to avoid tan lines.

Many people choose to sun tan without clothes to maximize tanning coverage, maximizing health benefits of sun exposure, increasing the sensitory experience and reducing or eliminating tan lines caused by the contrast of exposed and unexposed tanned skin. While some are content to simply sun tan in the privacy of their own private property, some governmental agencies have responded to more demand for clothing-optional sun tanning in public spaces.

As an example, Englischer Garten in urban Munich has meadows where nude sun tanning is the norm. In Denmark, clothing-optional sun tanning is the default dress code on all beaches, with the exception of two[1]. In other areas of the world, clothing-free sun tanning could be met with citation or fines. Clothing-optional beaches (also known as naturist, nude or nudist beaches) and other areas where quiet use or traditional use is tolerated, generally allow for such opportunities without fear of legal harassment or penalty. Even more beaches allow topfree tanning for women. Some describe beaches where nudity or topfree tanning is tolerated to be "more European".[2]. Geographic areas in the US with warm to tropical climates with extensive beach fronts often cater to such tourist opportunities, e.g. Haulover Beach, Gunnison Beach, Black's Beach and Baker Beach.

[edit] Preventing overexposure

Personal tanning dress is usually a reflection of preference.

Protection of the skin through use of a beach umbrella

To avoid sunburn or excessive exposure, staying out of direct sunlight is the primary defense.

If long sun exposure cannot be avoided or is desired one may use sunscreen or various over-the-counter creams to reduce sun exposure. The SPF (Sun Protection Factor) number on a sunscreen product shows its rated effectiveness. Products with a higher SPF number are those designed to provide more defense for the skin against the effects of solar radiation. However in 1998, the Annual Meeting of the American Association for the Advancement of Science reported that some sunscreens advertising UVA and UVB protection do not provide adequate safety from UVA radiation and could give sun tanners a false sense of protection.

Tanning oils or creams, when applied, are usually thicker on some parts of skin than on others. This causes some parts of skin to get more UVA and UVB than others and thus get sunburns. For this reason, improper application of tanning oils or creams may increase the occurrence of skin cancer and other skin diseases.^{[citation needed]}

For those who choose to tan, some dermatologists recommend the following preventative measures:

Make sure the sunscreen blocks both UVA and UVB rays. These types of sunscreens, called broad-spectrum sunscreens, contain more active ingredients. Ideally a sunscreen should also be hypoallergenic and noncomedogenic so it doesn't cause a rash or clog the pores, which can cause acne.
Sunscreen needs to be applied thickly enough to make a difference. People often do not put on enough sunscreen to get the full SPF protection. In case of uncertainty about how much product to use, or discomfort with the amount applied, switching to a sunscreen with a higher SPF may help.
Reapply sunscreen every 2 to 3 hours and after swimming or sweating. In direct sun, wear a sunscreen with a higher SPF (such as SPF 30). For playing sports the sunscreen should also be waterproof and sweatproof.
The rays of the sun are strongest between 10 a.m. and 4 p.m (see http://www.epa.gov/sunwise/actionsteps.html), so frequent shade breaks are recommended during these hours. Sun rays are stronger at higher elevations (mountains) and lower latitudes (near the equator). One way to deal with time zones, daylight saving time (summer time) and latitude is to check shadow length. If a person's shadow is shorter than their actual height, the risk of sunburn is much higher.
Wear a hat with a brim and anti-UV sunglasses which can provide almost 100% protection against ultraviolet radiation entering the eyes.
Be aware that reflective surfaces like snow and water can greatly increase the amount of UV radiation to which the skin is exposed.

The American Academy of Dermatology recommends the use of sunscreens, wearing sun protective clothing and avoiding the sun altogether.

[edit] Tanning and sunscreen

In his book: "Physician's guide to sunscreens" Nicholas J. Lowe pointed out, that one of the reasons for customers to reject sunscreen use is the reduction of tanning that is associated with good sunscreen protection.(chapter 7 page 81)^[28] He then reports about several tanning activators. The specific substances which he writes about are different forms of Psoralen. These substances were known to be photocarcinogenic since 1979.^[29]^[30]^[31] Despite the obvious photocarcinogenic effects the authorities dissallowed Psoralen only in July 1996.^[32]

Good sunscreens do not penetrate into the skin, but stay in the uppermost layer of dead cells (stratum corneum). If sunscreens would work in the way which is assumed by those who endorse the use of sunscreen, then they would prevent suntanning. (see How does sunscreen work?) (see tanning activator)

Considering that sunburn and an increased melanogenesis are initiated by the same mechanism (direct DNA damage) ^[3] it is an unrealistic expectation to acquire a long lasting tan through melanogenesis while avoiding those DNA damages that lead to sunburn if they occur in excess.