SimUVEx v2: A numeric model to predict anatomical solar ultraviolet exposure

Solar ultraviolet (UV) radiation has a dual effect on human health. Low UV doses promote the photosynthesis of vitamin D and regulate calcium and phosphorus metabolism, while an excessive UV exposure is the main cause of skin cancer, along with eye diseases and premature skin ageing. Nevertheless, the link between UV radiation levels and UV exposure is not fully understood since exposure data are limited and individual anatomical variations in UV doses are significant. For these reasons, a numeric simulation tool (SimUVEx) has been developed and validated in order to predict the dose and distribution of UV exposure received taking into account postural information and ambient irradiation data. SimUVEx is based on 3D graphics techniques usually used to render virtual environments to estimate the exposure of a 3D virtual manikin characterised as a triangular mesh surface. Each triangle receives a certain quantity of solar energy depending on the direct, diffuse and reflected radiation, the body surface orientation to the sun and the shadows from other parts of the body. The goals of the second version of SimUVEx are to move from individual-based to population-based (e.g., Switzerland and, eventually, Europe) exposure assessment, expanding temporal, spatial and morphological simulation capabilities. Outputs from SimUVEx version 2 will allow building exposure scenarios, identifying high-risk situations and producing reference dose ranges for typical outdoor occupational and leisure activities.