POTENTIAL ECOLOGICAL RISK OF METALS EMITTED FROM TRAFFIC ON THE LEAVES OF TREES IN TEHRAN, IRAN

The purpose of the current study was to investigate the effect of fuel quality on the contamination and potential ecological risk of metals in high-traffic areas. To this end, the leaves of street-side trees in Tehran were used as particle collectors. The concentration of Pb, Cd and Zn decreased but the concentration of Co and Cu increased in 2014 compared with 2012. The potential ecological risk of metals, Cd, Co, Cu, Ni, Pb, and Zn, decreased by %43 in 2014 compared to 2012. Despite the improvement of fuel quality in 2014, there was yet the moderate likelihood of potential ecological risk of metals in the study sites. It was revealed that the wear and tear of interior and exterior parts of vehicles remained significant, especially after the high-risk period of 2012. As conclusion, natural factors and air conditioning exacerbated the contamination of metal at local levels in Tehran. The purpose of the current study was to investigate the effect of fuel quality on the contamination and potential ecological risk of metals in high-traffic areas. To this end, the leaves of street-side trees in Tehran were used as particle collectors.