indoor tanning indoor tanning indoor tanning involves using a device that emits ultraviolet radiation to produce a cosmetic tan. typically found in tanning salons, gyms, spas, hotels, and sporting facilities, and less often in private residences, the most common device is a horizontal tanning bed, also known as a sunbed or solarium. vertical devices are known as tanning booths or stand-up sunbeds. horizontal low-pressure tanning bed first introduced in the 1960s, indoor tanning became popular with people in the western world, particularly in scandinavia, in the late 1970s. the practice finds a cultural parallel in skin whitening in asian countries, and both support multibillion-dollar industries. most indoor tanners are women, 16–25 years old, who want to improve their appearance or mood, acquire a pre-holiday tan, or treat a skin condition. across australia, canada, northern europe and the united states, 18.2% of adults, 45.2% of university students, and 22% of adolescents had tanned indoors in the previous year, according to studies in 2007–2012. as of 2010 the indoor-tanning industry employed 160,000 in the united states, where 10–30 million tanners visit 25,000 indoor facilities annually. in the united kingdom, 5,350 tanning salons were in operation in 2009. from 1997 several countries and us states banned under-18s from indoor tanning. the commercial use of tanning beds was banned entirely in brazil in 2009 and australia in 2015. as of 1 january 2017, thirteen u.s. states and one territory have banned under-18s from using them, and at least 42 states and the district of columbia have imposed regulations, such as requiring parental consent. indoor tanning is a source of uv radiation, which is known to cause skin cancer, including melanoma and skin aging, and is associated with sunburn, photodrug reactions, infections, weakening of the immune system, and damage to the eyes, including cataracts, photokeratitis (snow blindness) and eye cancer. injuries caused by tanning devices lead to over 3,000 emergency-room cases a year in the united states alone. physicians may use or recommend tanning devices to treat skin conditions such as psoriasis, but the world health organization does not recommend their use for cosmetic purposes. the who's international agency for research on cancer includes tanning devices, along with ultraviolet radiation from the sun, in its list of group 1 carcinogens. researchers at the yale school of public health found evidence of addiction to tanning in a 2017 paper. background ultraviolet radiation typical f71t12 71-inch, 100-watt, bi-pin tanning lamp ultraviolet radiation (uvr) is part of the electromagnetic spectrum, just beyond visible light. ultraviolet wavelengths are 100 to 400 nanometres (nm, billionths of a metre) and are divided into three bands: a, b and c. uva wavelengths are the longest, 315 to 400 nm; uvb are 280 to 315 nm, and uvc wavelengths are the shortest, 100 to 280 nm. about 95% of the uvr that reaches the earth from the sun is uva and 5% uvb; no appreciable uvc reaches the earth. while tanning systems before the 1970s produced some uvc, modern tanning devices produce no uvc, a small amount of uvb and mostly uva. classified by the who as a group 1 carcinogen, uvr has "complex and mixed effects on human health". while it causes skin cancer and other damage, including wrinkles, it also triggers the synthesis of vitamin d and endorphins in the skin. history sunlamp in the netherlands, 1930 in 1890 the danish physician niels ryberg finsen developed a carbon arc lamp ("finsen's light" or a "finsen lamp") that produced ultraviolet radiation for use in skin therapy, including to treat lupus vulgaris. he won the 1903 nobel prize in physiology or medicine for his work. until the late 19th century in europe and the united states, pale skin was a symbol of high social class among white people. victorian women would carry parasols and wear wide-brimmed hats and gloves; their homes featured heavy curtains that kept out the sun. but as the working classes moved from country work to city factories, and to crowded, dark, unsanitary homes, pale skin became increasingly associated with poverty and ill health. in 1923 coco chanel returned from a holiday in cannes with a tan, later telling vogue magazine: "a golden tan is the index of chic!" tanned skin had become a fashion accessory. in parallel physicians began advising their patients on the benefits of the "sun cure", citing its antiseptic properties. sunshine was promoted as a treatment for depression, diabetes, constipation, pneumonia, high and low blood pressure, and many other ailments. home-tanning equipment was introduced in the 1920s in the form of "sunlamps" or "health lamps", uv lamps that emitted a large percentage of uvb, leading to burns. friedrich wolff, a german scientist, began using uv light on athletes, and developed beds that emitted 95% uva and 5% uvb, which reduced the likelihood of burning. the world's first tanning salon opened in 1977 in berlin, followed by tanning salons in europe and north america in the late 1970s. in 1978 wolff's devices began selling in the united states, and the indoor tanning industry was born. devices lamps tanning lamps, also known as tanning bulbs or tanning tubes, produce the ultraviolet light in tanning devices. the performance (or output) varies widely between brands and styles. most are low-pressure fluorescent tubes, but high-pressure bulbs also exist. the electronics systems and number of lamps affect performance, but to a lesser degree than the lamp itself. tanning lamps are regulated separately from tanning beds in most countries, as they are the consumable portion of the system. beds look up tanning bed in wiktionary, the free dictionary. most tanning beds are horizontal enclosures with a bench and canopy (lid) that house long, low-pressure fluorescent bulbs (100–200 watt) under an acrylic surface. the tanner is surrounded by bulbs when the canopy is closed. modern tanning beds emit mostly uva (the sun emits around 95% uva and 5% uvb). one review of studies found that the uvb irradiance of beds was on average lower than the summer sun at latitudes 37°s to 35°n, but that uva irradiance was on average much higher. the user sets a timer (or it is set remotely by the salon operator), lies on the bed and pulls down the canopy. the maximum exposure time for most low-pressure beds is 15–20 minutes. maximum times are set by the manufacturer according to how long it takes to produce four "minimal erythema doses" (meds), an upper limit laid down by the fda. an med is the amount of uv radiation that will produce erythema (redness of the skin) within a few hours of exposure. high-pressure beds use smaller, higher-wattage quartz bulbs and emit a higher percentage of uva. they may emit 10–15 times more uva than the midday sun, and have a shorter maximum exposure time (typically 10–12 minutes). uva gives an immediate, short-term tan by bronzing melanin in the skin, but no new melanin is formed. uvb has no immediate bronzing effect, but with a delay of 72 hours makes the skin produce new melanin, leading to tans of longer duration. uva is less likely to cause burning or dry skin than uvb, but is associated with wrinkling and loss of elasticity because it penetrates deeper. commercial tanning beds cost $6,000 to $30,000 as of 2006, with high-pressure beds at the high end. one manhattan chain was charging $10 to $35 per session in 2016, depending on the number, strength, and type of bulbs. this is known as level 1–6 tanning; level 1 involves a basic low-pressure bed with 36 x 100-watt bulbs. depending on the quality of the bed, it may contain a separate facial tanner, shoulder tanners, a choice of tanning levels and uva/uvb combinations, sound system, mp3 connection, aromatherapy, air conditioning, a misting option and voice guide. there are also open-air beds, in which the tanner is not entirely enclosed. booths tanning booths (also known as stand-up sunbeds) are vertical enclosures; the tanner stands during exposure, hanging onto straps or handrails, and is surrounded by tanning bulbs. in most models, the tanner closes a door, but there are open designs too. some booths use the same electronics and lamps as tanning beds, but most have more lamps and are likely to use 100–160 watt lamps. they often have a maximum session of 7–15 minutes. there are other technical differences, or degrees of intensity, but for all practical intents, their function and safety are the same as a horizontal bed. booths have a smaller footprint, which some commercial operators find useful. some tanners prefer booths out of concern for hygiene, since the only shared surface is the floor. lotions and goggles goggles for indoor tanning before entering a tanning unit, the tanner usually applies indoor tanning lotion to the whole body and may use a separate facial-tanning lotion. these lotions are considerably more expensive than drugstore lotions. they contain no sunscreen, but instead moisturize the skin with ingredients such as aloe vera, hempseed oil and sunflower seed oil. they may also contain dihydroxyacetone, a sunless tanner. so-called "tingle" tanning lotions cause vasodilation, increasing blood circulation. goggles (eye protection) should be worn to avoid eye damage. in one 2004 study, tanners said they avoided goggles to prevent leaving pale skin around the eyes. in the us, cfr title 21 requires that new tanning equipment come with eye protection and most states require that commercial tanning operators provide eye protection for their clients. laws in other countries are similar. prevalence tanning-device use tanning booth indoor tanning is most popular with white females, 16–25 years old, with low-to-moderate skin sensitivity, who know other tanners. studies seeking to link indoor tanning to education level and income have returned inconsistent results. prevalence was highest in one german study among those with a moderate level of education (neither high nor low). the late teens to early–mid 20s is the highest-prevalence age group. in a national survey of white teenagers in 2003 in the us (aged 13–19), 24% had used a tanning facility. indoor-tanning prevalence figures in the us vary from 30 million each year to just under 10 million (7.8 million women and 1.9 million men). the figures in the us are in decline: according to the centres for disease control and prevention, usage in the 18–29 age group fell from 11.3 percent in 2010 to 8.6 percent in 2013, perhaps attributable in part to a 10% "tanning tax" introduced in 2010. attitudes toward tanning vary across states; in one study, doctors in the northeast and midwest of the country were more likely than those in the south or west to recommend tanning beds to treat vitamin d deficiency and depression. tanning bed use is more prevalent in northern countries. in sweden in 2001, 44% said they had used one (in a survey of 1,752 men and women aged 18–37). their use increased in denmark between 1994 and 2002 from 35% to 50% (reported use in the previous two years). in germany, between 29% and 47% had used one, and one survey found that 21% had done so in the previous year. in france, 15% of adults in 1994–1995 had tanned indoors; the practice was more common in the north of france. in 2006, 12% of grade 9–10 students in canada had used a tanning bed in the last year. in 2004, 7% of 8–11-year-olds in scotland said they had used one. tanning bed use is higher in the uk in the north of england. one study found that the prevalence was lower in london than in less urban areas of the country. density of facilities tanning facilities are ubiquitous in the us, although the figures are in decline. in a study in the us published in 2002, there was a higher density in colder areas with a lower median income and higher proportion of whites. a study in 1997 found an average of 50.3 indoor-tanning facilities in 20 us cities (13.89 facilities for every 100,000 residents); the highest was 134 in minneapolis, mn, and the lowest four in honolulu, hawaii. in 2006 a study of 116 cities in the us found 41.8 facilities on average, a higher density than either starbucks or mcdonald's. of the country's 125 top colleges and universities in 2014, 12% had indoor-tanning facilities on campus and 42.4% in off-campus housing, 96% of the latter free of charge to