Air Pollution Biomonitoring in Urban Ecosystems with Aesculus hippocastanum

Several phytomonitoring surveys in urban ecosystems have been undertaken during the last years. The questions about the role of natural variables in conditions of increased anthropogenic pressure, as well as the background levels of pollutants in the background sites in urban areas, are still open. Our study was focused on bioaccumulation of heavy metals and toxic elements in leaves of Aesculus hippocastanum L. from two air quality station types: background and traffic. Consequently, the pollutant levels in 3 Bulgarian cities with different geographical characteristics were compared. Nevertheless, results revealed similar levels of heavy metals and toxic elements in the studied cites, which suggested the anthropogenic factor as a major for deposition. In addition, all three cities are at risk of atmospheric deposition of Pb in the areas located around intensively loaded road arteries. PCA illustrated that the concept of "urban background sites" is disputable in some cases.Based on the results horse chestnut is recommended for urban green infrastructures.