Horizon Shielding Factor: A Measure to Assess UV Exposure in Different Microenvironments

Abstract

BACKGROUND AND AIM Skin cancer incidence rates have increased over recent decades worldwide. Ultraviolet radiation (UVR) is one of the main causes of skin cancer, as it induces mutations resulting from epidermal DNA damage. Exposure of people to UVR varies a lot depending on different factors such as the location of an individual. Additionally, UVR exposure can, for example, be lower due to shading effects. Being able to precisely measure UV exposure with a high repeatability on an individual level and to assess which microenvironments successfully reduce UV-exposure is, therefore, of high importance. METHODS In this analysis, we evaluated wearables at different body positions measuring ultraviolet radiation when worn during daily activities at different locations. First, we analyzed which of the body positions provide the most robust measurements. We then showed, that the measurements from the optimal body position can be used to infer the measurements taken at other positions. Using this optimal position, we devised a new measure, the horizon shielding factor, to evaluate the effect of horizon shielding. To explore if high/low horizon shielding factor values coincide with particular geospatial attributes, we inspected those values in their microenvironment on open street maps and found homogenous results per microenvironment. CONCLUSIONS The horizon shielding factor that has been developed in this project can be used to assess which microenvironments successfully reduce UV-exposure. It can be used in the future to find routes of transportation with less UV exposure due to horizon shielding. Systematic mapping of the horizon shielding factor in a given region may help policy makers and developers of new infrastructural projects to succeed in meeting the goals set by e.g. the National Climate Adaptation Strategy. KEYWORDS •Ultraviolet radiation exposure •Exposure assessment in microenvironments •Horizon Shielding