Radiation: Sunbeds

An expert in the field of radiation protection has referred to the use of tanning parlours as "an industrial-scale radiation exposure experiment involving significant parts of the populations of Northern Europe and America." Approximately 10 per cent of the population of Northern Europe use sunbeds on a regular basis for tanning purposes. Sunbed radiation can produce adverse health effects similar to those of natural sunlight, most notably in fair-skinned persistent users. In this context it is a subject of great concern that approximately 40 per cent of sunbed users in the United Kingdom have fair skin. The same study identified that 20 per cent of people questioned had more than 100 annual sunbed sessions, and 5 per cent had used sunbeds for 15 to 20 years.

Natural UV radiation reaching the Earth's surface consists of approximately 95% UVA and 5% UVB radiation. Tanning parlours use different types of sunbeds, some emitting more, some emitting less UVB as compared to UVA. In the past, there was a trend towards a decrease of UVB and a corresponding increase in UVA. This was based on the experience that excessively UVB-rich sunbeds easily cause intermittent overexposures and risks of acute sunburns with a possible increased melanoma risk. On the other hand, excessive UVA exposure has lately been discussed as a possible melanoma risk factor in the scientific and regulatory community. Many sunbed manufacturers are now returning to relative amounts of UVA and UVB that mimic the natural composition in sunlight.

Sunbeds mainly emit UVA radiation which activates the melanin pigment already embedded in the upper skin cells. This immediate tan begins to fade within a few hours after cessation of exposure, but can persist following sufficient and repeated exposure. The small amounts of UVB emitted by sunbeds induce the so-called delayed tanning reaction, where new melanin is produced and distributed between the upper skin cells.

Increasing numbers of people rely on sunbeds for whole-body tanning and to tan beyond their normal complexion. This forced tanning is associated with DNA damage in melanocytes, the cells that produce the dark-coloured melanin pigment in the skin. In genetically dark-skinned individuals, relatively little DNA damage is sufficient to bring about the extra-tanning effect. In contrast forced tanning in fair-skinned individuals is associated with a lot of DNA damage. It is mainly fair-skinned people who are keen to darken their complexion.

Sunbeds are not as successful in producing a tan as the people using them would like them to be. A recent British survey reported that only 2/3 of the regular sunbed users interviewed had achieved moderate tanning, while 1/3 had gained a mild tan; some also reported patchy tanning.

A recent survey suggests that 40 per cent of sunbed users believe they can prevent sunburning on holiday by obtaining a tan beforehand. To put things into perspective: a dark tan on a white skin offers a sun protection factor of between 2 and 4. But more importantly, a tan is no defence against long-term UV damage such as skin cancer.

Sunbeds mainly emit UVA radiation, which produces a tanning effect by increasing the amount of melanin pigment in the upper skin layers. Even though this is designed as a defence against further UV damage, the darkening as such provides little extra protection. UVB, on the other hand, stimulates cells to produce a thicker epidermis, which offers slightly more protection against further exposure to UV radiation.

Few studies have been undertaken to systematically assess the dangers of sunbed use, and the picture remains equivocal. Sunbeds for self-tanning purposes have been available for the last two decades and due to the long latency period for skin cancer and eye damage it has been difficult so far to demonstrate any long-term health effects.

The majority of tanning parlours provide inadequate advice to their customers. The use of eye protection such as goggles or sunglasses should be mandatory. However, as sunbed users aim to have an even tan, they often decide against protecting any part of their body.

Users have reported a range of short-term symptoms including itching, dryness and redness of skin, freckling and photosensitivity. Common outcomes in the longer term, especially in fair-skinned people, may involve blistering of the skin. Sagging and wrinkling of the skin are an almost certain price to be paid by frequent sunbed users.

The new technology sunbeds are said to emit "safe" UV radiation. However, the original presumption that UVA is a safe form of UV radiation does not hold. If nothing else, it enhances skin ageing but, most likely, UVA also plays a role in skin cancer promotion. So what about the "healthy tan" that many manufacturers advertize? The results of a few simple measurements and calculations should suffice to put such claims into perspective:

Average UVA levels of sunbeds easily reach midday solar UVA levels in the United Kingdom, but some sunbeds may exceed maximum values up to 20 times.

UVB levels of sunbeds may be as low as 1/20 of the maximum solar UVB levels during the British summer, however, they may also exceed them threefold.

Assuming the average UVA and UVB levels of the sunbeds tested, the carcinogenic effect of sunbed use over a period of 10 minutes corresponds with an exposure to 10 minutes of Mediterranean summer sun. Regular sunbed use therefore contributes significant amounts to the user's annual UV radiation exposure, especially as it involves whole-body exposure - the exposed skin area in sunbed tanning is at least twice as large as the average sunbather's.

Even though the causes of malignant melanoma are not fully understood, tumour development appears to be linked to occasional exposure to intense sunlight. Curiously, tumours are most frequent on body sites that are rarely exposed to the sun. Sunbeds subject their users to intermittent high exposures of UVA and UVB radiation – this may provide the ideal setting for the development of malignant skin cancer. However, the few epidemiological studies that have been carried out to date have not provided any consistent results.

Tanning beyond the normal complexion is associated with DNA damage in melanocytes, the cells that produce the dark-coloured melanin pigment in the skin. Even a small tanning effect requires a lot of DNA damage in the fair-skinned population. Therefore, regular use of sunbeds will significantly increase your chances of getting skin cancer if you are fair-skinned. The International Commission on Non-Ionizing Radiation Protection states that "the use of sunbeds for cosmetic purposes is not recommended." Regular exposure should not exceed two sessions per week with a maximum of 30 sessions per year. Australian cancer control organizations go even further, calling for tanning salons and advertizements for sunbeds to display health warnings – similar to those required on cigarette packets.

People who:

• are under 18,
• have very fair skin,
• burn easily or tan poorly
• have a lot of freckles or moles,
• have had skin cancer or have a family history of the disease,
• are using medication that could make their skin more sensitive to UV, and
• are already have extensive "sunlight" damage