This article presents measurements of solar UV radiation taken in 2007 in Silesian Province in view of erythema efficiency. People’s exposure to UV radiation was examined and covereved aspects of health, season, weather conditions, number of trees and amount of time spent outdoor. Irradiance was measured in horizontal plane and in south, north, east and west directions in vertical plane. The area chosen for measurements was partially urbanised and afforestated. The strongest irradiance appeared in horizontal plane measurements and in south direction. The weakest irradiance appeared in northern direction. It shows that people’s hazard to solar UV depends not only on season and climate conditions, but also, to a great extent, on local environmental conditions – urbanisation and afforestation.