Health risks of UV radiation

Medicine showed that small amounts of UV are beneficial for people and essential in the production of vitamin D. UV radiation is also used to treat several diseases, including rickets, psoriasis, vitiligo, eczema and jaundice. This takes place under medical supervision and the benefits of treatment versus the risks of UV radiation exposure are a matter of clinical judgment.

The World Health Organisation (WHO) warns that prolonged human exposure to solar UV radiation may result in acute and chronic health effects on the skin, eye and immune system.

(1) Sunburn (erythema) is the best-known acute effect of excessive UV radiation exposure. Over the longer term, UV radiation induces degenerative changes in cells of the skin, fibrous tissue and blood vessels leading to premature skin aging, photodermatoses and actinic keratoses. Between 2 and 3 million non-melanoma skin cancers, e.g. basal cell carcinomas and squamous cell carcinomas, are diagnosed each year, but are rarely fatal and can be surgically removed. Approximately 130,000 malignant melanomas occur globally each year, substantially contributing to mortality rates in fair-skinned populations. An estimated 66,000 deaths occur annually from melanoma and other skin cancers.

(2) Another long-term effect is an inflammatory reaction of the eye. In the most serious cases, skin cancer and cataracts can occur. Worldwide some 12 to 15 million people become blind from cataracts annually, of which up to 20% may be caused or enhanced by sun exposure according to WHO estimates.

(3) Furthermore, a growing body of evidence suggests that environmental levels of UV radiation may suppress cell-mediated immunity and thereby enhance the risk of infectious diseases and limit the efficacy of vaccinations. Both of these act against the health of poor and vulnerable groups, especially children of the developing world

WHO cautions also that fairskinned and darkskinned people are equally at risk of UV-related overexposure such as skin cancers. The risk of UV radiation-related health effects on the eye and immune system is independent of skin type....