Prediction of anatomical exposure to solar UV: A case study for the head using SimUVEx v2

Abstract

Excessive exposure to solar ultraviolet (UV) radiation is the main cause of skin cancer. The dose-response between UV exposure and skin cancer occurrence is not yet fully understood since UV exposure is highly heterogeneous and strongly influenced by host and behavioural factors, such as posture, orientation to the sun, skin complexion and clothing. To address this issue, a three-dimensional (3D) numeric model (SimUVEx) has been developed to assess dose and distribution of anatomical UV exposure. The model uses 3D computer graphics techniques to compute UV radiance on the basis of postural information and ambient irradiation data, without necessitating time-consuming individual dosimetry, ensuring a wide potential use in skin cancer prevention and research. With the purpose to improve simulation capabilities in order to obtain more realistic scenarios and quantify effective sun protection strategies, a new version has been released, SimUVEX v2. Among new features, a specific morphology for the most sun-exposed body area, the head, has been added. We selected three different styles of hat (cap, wide-brimmed hat and helmet) to compare scenarios with and without solar protections considering the relative contribution of the direct, diffuse and reflected radiation. It was found that, sites directly covered apart (e.g., forehead and top of the head), hats with a wide brim are necessary in order to provide reasonable protections around facial zones on which non-melanoma skin cancers commonly occur, such as nose and cheeks.