Assessment of heavy metal pollution in soil and bottom sediment of Upper Egypt: comparison study

Abstract

Abstract Background Aswan and Luxor Governorates are characterized by multifaceted activities such as cement, chemicals, fertilizers, detergents, nitrogen fertilizer factory at Aswan, the sugar and diary factory at Kom Ombo, and several other factories such as the sugar, pulp, paper, ferrosilicon, and phosphate factories at Edfu, urbanization and agriculture. In addition, there is a main sewage station which is used for irrigation of many crops. Assessing the pollution of soil and sediment with some heavy metals in these areas is the main aim of the current work. Results The average heavy metals content in the studied cultivated soils and Nile sediments are above the acceptable levels. Generally, Nile sediments and cultivated soils at Aswan and Luxor were unpolluted to moderately polluted with heavy metals. Pollution indices indicated that the studied Nile sediments were at considerably ecological risk from Cd (Er = 138.89) and Zn (Er = 140.52). In contrast, the cultivated soil was at very high ecological risk from Cd (Er = 295.24). Conclusions The current research revealed that the soil and sediments in the Upper Egypt are less polluted than Lower Egypt. Thus, the concentrations of toxic elements are increased from south to north direction in Egypt along the Nile River. The sources of the toxic metals may possibly be natural or anthropogenic in the studied area. The anthropogenic source is resulting from paper, pulp, ferrosilicon factories, and phosphate mining at Edfu. In addition, there are some polluting industries such as sand quarry, shale mining, and the nitrogen fertilizer factory at Aswan. On the other hand, the natural sources of toxic waste are the drains during the seasonal flash floods.