ASSESSMENT OF HEAVY METALS CONTAMINATION AND SEDIMENT QUALITY IN SHATT AL-ARAB RIVER, S IRAQ
In Shatt Al-Arab river, there is high concentration of population, industries, domestic sewage, and industrial effluents with high organic matter discharged untreated, in addition to oil spilling accidents caused to dump a lot of heavy metals cause to health risk for people that live in Basrah city. Concentrations of six heavy metals (Cr, Cu, Ni, Pb, Mo, and Zn) of the sediments in Shatt Al-Arab river were detected in this study to evaluate their level in five selected sites in Shatt Al-Arab river, Site 1 in Maaqal port, site 2 in Basrah center, Site 3 in Abu Flus port, Site 4 in Seeba area in Abu AlKhassib, and Site 5 in Fao area. The range of the measured concentrations in the studied sediments are as follows: 170 – 491 mg/l for Cr, 31 – 40 mg/l for Cu, 99.7 – 116 mg/l for Ni, 11 – 17 mg/l for Pb, 2 – 7.96 mg/l for Mo, and 108 – 127 mg/l for Zn. arrange of heavy metals from higher to lower mean content of this area as : Cr > Zn > Ni > Cu > Pb > Mo. Correlation coefficient between heavy metals could be indicate to same source area. To assess metal contamination of sediments, contamination factor (CF) was applied. The CF for Cr in sites 1 and 2 was very high contamination, while it was considerable contamination in site 3 for Cr, and sites 1 and 2 for Mo. CF for Ni, Zn , and Cu was moderate contamination, and the same degree of contamination for Mo in sites 3, 4 and 5. CF for Pb was low contamination in the most studied sites. Maximum degree of contamination was found in sites 1 and 2 as indicator to higher contamination in these areas. Sediments are enriched for metals in the following order: Cr > Mo > Ni > Zn > Cu > Pb. US environmental Protection Agency’s (USEPA) Guidelines and contaminant limits of heavy metals according to the environmental management (C.F.M) were also applied and evaluated by comparison with studied heavy metals and showed that concentrations of Cr, Ni, Mo, Zn and Cu were heavily to moderately polluted, while all the selected sites were un polluted by Pb element.