Heavy metals distribution in the soils of Peshawar valley, Northern-Pakistan

摘要

Information about metals concentrations in soil profiles of Peshawar-Pakistan in relation to their parent material is in scarcity. The study was aimed to identify the source of metals in soils and to determine the level of depletion and enrichment. Twenty two soil profiles derived from alluvium, piedmont alluvium, loess and re-deposits loess underlain by quaternary sediments with their respective parent materials were sampled and analyzed for metals by AAS. The average value of Ca, Fe, K, Mg, Na was significantly greater (p&0.05) in piedmont soils than red Murree shales. Cadmium was found to be high in all soils than the parent material. There was no significant difference in total content of Cu in all soils. Total content of Cd, Cr, Mn and Zn was found to be significantly greater (p&0.05) in piedmont soils than alluvium and loess soils, similarly Ni and Pb were significantly greater (p&0.05) in loess soils than piedmont and alluvium soils. The concentrations of Cr, Pb and Zn were significantly greater (p&0.05) in the A horizon of piedmont and alluvium soils than B horizon. The total content of all trace elements except for Cd and Ni was found to be significantly greater (p&0.05) than the reported mean for world soils. There was no significant difference between total trace elements content except for Cd and Ni between soils and parent materials. Data suggested no depletion or enrichment in all metals. All metals were evenly distributed and derived from similar parent material of sedimentary origin. These values could be considered as baseline levels for comparison with soils contaminated due to anthropogenic activities.