Urban environmental conditions and solar ultraviolet exposure: Comparative analysis of UV-related factors

Urban conditions can significantly change the level of solar ultraviolet exposure. In densely built cities, higher surface temperatures, air pollution and reflection from concrete and glass create an additional ultraviolet load. As a result, the same weather conditions may produce different levels of total exposure in different cities or districts, with possible consequences for skin diseases in the urban population. The purpose of the study was to compare the main UV-related factors in urban areas and to estimate their contribution to cumulative ultraviolet burden. The analysis was based on data from the World Health Organization, NASA, the Copernicus Climate Change Service and the European Environment Agency. The results showed that when the average UV Index increased from 3–4 to 8–10, the total ultraviolet burden increased by about 2.6 times. A temperature anomaly of +5 °C associated with the urban heat island effect increased exposure by 11 %, while PM2.5 concentrations above 35 µg/m3 increased it by 18 %. Reflection from concrete and glass surfaces added a further 10–18 % to direct ultraviolet exposure.