Environmental Assessment of Heavy Metal Distribution in Sediments of Tigris River within Baghdad City

This work contributes to the monitoring of Tigris river pollution by assessing the degree of heavy metals pollution in the sediment samples. The order of the mean concentrations of examined heavy metals: Cr>Zn>Ni >Pb>Cu>Cd. The results indicated that the entire tested heavy metal exhibit higher values than ISQG for fresh water sediments. Geo-accumulation Index (Igeo), Enrichment Factor (EF), Contamination Factor (CF), Degree of Contamination (Cd) and Pollution Load Index (PLI) were applied to evaluated heavy metals contamination in the sediment samples. Based on I-geo the sediment of Tigris river within the study area can be considered to be a strongly to extremely polluted with Cd, while the Igeo values of Pb show moderately polluted degree. With respect to specific sites, high EF values (e.g., 97.89 for Cd, 9.73 for Pb, 5.07 for Cr, 3.98 for Ni, 2.90 for Cu and 2.52 for Zn) are found at Site 3, which was located at the downstream and continuously receives a vast amount of wastewater and other wastes of the city. According to the calculated Cd values, the pollution levels for the sites in the following order: 3>1>2, suggesting that the site located in the downstream is more seriously polluted by heavy metals than other sites, attributed to the feeding river input. Furthermore, site 3 displayed the highest PLI value and reflects the highest presence of all the examined heavy metals; indicating that this site is considerably affected by different anthropogenic activities.