The effect of human activities on the pollution of water in southwest Giza area, Egypt

Southwest Giza area is one of the most complicated regions in Egypt because of the combination of agricultural, industrial and urbanization activities with few studies about water resources contamination with heavy metals. In this study, ten surface water samples and eight groundwater samples were collected and analyzed for pollution with Fe, Mn, As, Cr, Cd, Pb and Cu. The samples were collected randomly according to the topographic locations and accessibility. The surface water is suitable for both drinking and irrigation use according to its salinity (total dissolved solids, TDS< 500 mg/l) and content of major ions. Unfortunately, some samples contain concentrations of As, Cd, Cu and Pb higher than the WHO drinking water guidelines. The groundwater samples have TDS ranging from 204 to 2,100 mg/l. Also, the groundwater contains higher concentrations of Fe, Mn and As than surface water. The highest concentrations of heavy metals As, Cd and Pb were recorded in the desert fringes and close to the industrial complexes indicating the role of geological sediments in the transportation and migration of pollutants. The unconfined part of the Quaternary aquifer in the desert fringes is more vulnerable to contamination. The results of this study reflect the role of human and industrial activates in polluting water resources with heavy metals, which puts the aquatic environment in the study area under stress.