Urban soils' quality monitoring in Zagreb

Urban soils require special attention, either due to various ways of environment usage, the large number of pollution sources or other types of soil quality degradation. Soil pollution in urban environments depends on the type of pollutant, intensity of soil exploitation and environmental conditions. It ultimately affects human health through direct intake through the skin, respiratory or gastrointestinal tract. Therefore, it is important to recognize in time possible threats caused by polluted urban soils, but as well to suggest best practices to sue such soils according to the quality indicators. Urban soils' quality monitoring programme in Zagreb commenced in 2015 and is still ongoing. During 2021 activities of the Programme included soil sampling at 30 urban locations where during 2015. high levels of potentially toxic elements (i.e., higher than the maximum allowed concentrations according to Croatian government regulation on the protection of the agricultural land from pollution) were recorded. Soil analyses included measurements of main chemical properties and trace elements. Results were compared with available governmental data, but as well Central Croatia soil data, soil worldwide and average continental crust composition. Furthermore, soil quality was evaluated using statistical analyses and geostatistics. Results show that although concentrations of some metals (Cd, Cr and Cu) decreased, others (Hg, Ni, Pb and Zn) are still above legally set maximum values.