(Introduction) Climate change refers to the global shift in weather patterns occurring over long periods of time. These changes encompass temperature, rainfall, wind speeds and cloud cover. Climate change has accelerated rapidly in the past half century and while international focus has concentrated on the environmental and economic consequences, the effects on human diseases such as skin cancer have been relatively under-represented. The association between ultraviolet (UV) exposure from the sun and the development of malignant skin disease has long been recognized but is still not completely understood. The relationship between climate change and UV exposure will be explored in an attempt to qualify the impact of climate change on skin cancer.
(Ultraviolet radiation) Ultraviolet radiation (UVR) occupies the space between visible light and X-rays on the electromagnetic spectrum. The colour violet corresponds to the shortest wavelength in visible light and UV actually means ‘beyond violet’ (from the Latin ultra, meaning ‘beyond’). UV light can be further subdivided in terms of wavelength; ‘long wave’ UV with a range of 320–400 nanometres (nm) is known as UV-A; ‘medium wave’ UV with a range of 290–320 nm is known as UV-B; and ‘short wave’ UV with a range of 100–290 nm is known as UV-C.1 The wavelength of light is inversely proportional to its frequency and higher frequencies of light possess more energy. Hence UV-C carries the most energy and is the most damaging to biological systems. While UVB causes considerable DNA damage in the skin, UVA has only recently been shown to induce pyrimidine dimerizations and generate reactive oxygen and nitrogen species which damage DNA, proteins and lipids.2 The immunosuppressive effect of UVR contributes to its carcinogenic activity. Any one of these effects of UVR may contribute to the induction of skin cancers by other agents such as viruses, X-rays or chemical carcinogens.
(Conclusion) In conclusion, ozone depletion and climate change are separate entities which are intricately linked. They both have the potential to increase the incidence of skin cancer through different means. Over the last 30 years ozone depletion has received much of the attention, leading to the Montreal Protocol; heralded by Kofi Annan as ‘perhaps the single most successful international agreement to date. Focus must now shift towards analyzing the social and behavioral changes that will come about through climate change. Warmer, drier weather in the UK is likely to encourage people to spend more time outdoors and increase their exposure to UVR. The consequence will be an increase in the incidence of skin cancer brought about by behavioral change rather than environmental change. The world has had 30 years of public health initiatives and awareness campaigns. These must be heeded and acted upon now to protect the public from this preventable threat.