Outdoor workers exposed to UV radiation: comparison of UV index forecasting methods

Ultra-Violet (UV) radiation covers only a minimal part of solar spectrum (5%) but produces severe effects on human health. Everyone is exposed to Sun but some outdoor workers categories are exposed not only in their leisure time but also during their working activities. To protect outdoor workers health, daily estimates of UV radiation are needed and without a national service providing a measured UV Index (UVI) in the Italian territory, UVI forecasting methods are welcomed. Forecasting methods can be classified in two major groups: Methods based on the estimation of the UV total irradiance from solar total irradiance and methods based on regression models of measured UVIs. The former have greater uncertainties (about 30%) and are more suitable for epidemiologic studies, the latter, due to their better precision (about 10-20%), are more suitable for daily UVI evaluation.