Assessment of heavy metal pollution of plants grown adjacent to power generators in Ramadi city

Abstract

Tree leaves are a useful tool for environmental quality monitoring and heavy metal soil pollution assessment. This study aimed to assess the possibility of heavy metals’ accumulation in the leaves of urban plants as a biological indicator of soil pollution. The plant leaf and soil samples were collected from 51 sites adjacent to power generators in Ramadi-Iraq. Six common plant species, namely, Albizia lebbeck, Conocarpus lancifolius, Dodonaea viscosa, Eucalyptus camaldulensis, Ficus microcarpa, and Ziziphus spina-christi were selected. The highest heavy metal content was found in Conocarpus viscosa leaves followed by Dodonaea viscosa . These two plants have a significant difference (p<0.05) in the heavy metal content compared to other plants. The total average of plant heavy metal concentration was as follows: Mn (45.23), Cu (12.49), Ni (7.55), Pb (6.49), Cr (6.37), Co (2.04), Cd (0.57) mg per kg. Concentrations of heavy metals in leaves have the trend as Mn> Cu> Ni> Pb> Cr> Co> Cd, whereas, the heavy metal bioaccumulation factor (ACF) in plants follows by the order: Zn> Cu> Cd> Mn> Co> Pb> Ni> Cr. A high concentration of cobalt, cadmium, chromium, nickel, and lead are found in the plant leaves compared to the Food and Agriculture Organization / World Health Organization (FAO/WHO) permissible values. This supports the claim that the leaves of the plant can be used as a good indicator of heavy metal accumulation.