Effect of Air Pollution on Leaf Heavy Metals Concentrations (Fe, Cu, Zn and Mn) of Box Elder (Acer negundo) and Oriental Plane (Platanus orientalis) (Case Study: Urmia City)

Heavy metals are of most important environmental pollutants. Industrial activities and using pesticides are mainly causing environment to be polluted by these elements. This study aims to investigate the effect of air pollution on concentration of leaf heavy metals (Fe, Cu, Zn and Mn) of urban green space’s trees and their tolerance in Urmia. For this purpose, leaf samples of Acer negundo and Platanus orientalies individuals were collected in August 2013 and May 2014 from five different regions with different level of air pollution and their heavy metals concentrations were measured. Regarding to increasing of air pollution in the second year comparing to the first year, the accumulation of most elements had been increased by the tree species. In general, P. orientalies was considered as more tolerable species comparing to A. negundo due to higher accumulation even more than permissible defined threshold. Studied species, also, had lower and higher accumulation in the control and polluted places respectively, so it could be possible to use these species to differentiate between the polluted and unpolluted areas.