Sunbed use as a melanoma time bomb?
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.