LAUSR

Solar ultraviolet-B (UV-B) radiation has played a crucial role for the evolution of life on Earth, and potential changes in its levels could impact the health and the functionality of humans and the ecosystems. Furthermore, optimal UV exposure behaviors, that ensure balance between the risks and the benefits of exposure to UV-B radiation depend on several environmental and physiological factors and cannot be easily determined. The present study provides a review of the current state of knowledge relative to the effects of UV-B radiation on human health. A brief description of the physical mechanisms that control the levels of solar UV-B radiation at the Earth's surface is provided, with special emphasis to the role of ozone and the importance of the Montreal protocol. A comprehensive review of the studies reporting the current trends in the levels of surface solar UV-B radiation and projections of its future levels has been performed and reveals the dominant role of climatic changes in the long-term variability of UV-B radiation. The review provides strong evidence that despite the success of the Montreal Protocol the future evolution of the levels of solar UV-B radiation at the Earth's surface is not certain.