Comparison of the polycyclic aromatic hydrocarbons and heavy metal concentrations in soil and leaves of eucalyptus plants at Kirkuk, Iraq

Abstract

The polycyclic aromatic hydrocarbon (PAH) concentrations in the leaves of plant (eucalyptus) and the average concentrations of total heavy metals (Pb, Cu, Ni, Cr, and Cd) at Kirkuk Oil Refinery and the areas around were determined in 15 selected locations using GPS. The picking up of samples were carried out on March 2011. The average concentrations of the analyzed heavy metals (Pb, Cu, Ni, Cr, and Cd) in soil were 9.0, 13.1, 52.5, 71.2, and 13.3 ppm, while in eucalyptus leaves were 3.4, 6.0, 36.6, 48.5, and 11.9 ppm, respectively. The heavy metal concentration in soil and leaves in descending ordered are Cr>Ni>Cd>Cu>Pb. The average concentrations of PAHs in soil indicate 14.6 ppb, while in the leaves of the plant eucalyptus indicate 90.3 ppb. The concentration of heavy metals and PAHs in the soil and in the leaves of plants appeared to have almost the same distribution pattern. The results of heavy metals and PAHs show distribution of concentration toward wind directions and away from the site of Kirkuk Oil Refinery, e.g., SE direction. This indicates the meteorological conditions represented by the wind direction and the rainfall, which plays an important role in distribution and deposition of pollutant metals.