Ecological and Health Risk Assessment of Trace Metal Pollution in Vegetable Field Soils from the Eastern Nile Delta, Egypt

The accumulation of trace metals in vegetable field soils is of expanding worry because of the potential health hazards and its detrimental effects on soil ecosystems. To investigate the state of trace metal pollution in vegetable field soils, 60 surface soil samples were collected from vegetable fields across the Eastern Nile Delta region, Egypt. The results explained that the concentrations of Cu, Mn and Ni were lesser than their corresponding background values, while the concentrations of Cd, Co, Pb and Zn were exceed their background values. The pollution indices showed that the study soil experienced low to moderate contamination, and the Cd and Cr contamination was serious. The hazard index values of nine trace metals signified that there no adverse non-carcinogenic risk for adults and children. The carcinogenic risk of Cd, Co, Ni and Pb for both age groups was within the acceptable limits, while Cr had critical carcinogenic hazard to children. Overall, the quality of studied soils is relative safety, although some samples impose serious pollution problems by Cd and Cr. Thus, properly monitor trace metals and soil management action should be applied to reduce further soil pollution in vegetable fields in the Eastern Nile Delta.

Assessment of heavy metal pollution in the sediments of Dwars River, South Africa

The Dwars River in Limpopo Province, South Africa is being affected by anthropogenic activities such as mining, agriculture and human settlement in its catchment. The objectives of the study were to assess trace metal pollution, to determine possible sources of pollutants in the river and the potential impact on the ecosystem, aquatic biota and humans. Water and sediment samples were collected and analyzed for the following selected metals: Cr, Cu, Fe, Mn, Ni, Pb and Zn. The enrichment factor (EF) and geo-accumulation index (Igeo) were used to determine the extent of trace metal pollution in the sediments. The concentrations of Cr, Fe, Mn, Ni, and Zn in the Dwars River sediments were much higher than the average shale values, which indicated that the contamination of these metals might be caused by human activities. The enrichment factor (EF) results showed that Cr and Ni accumulated to severe enriched level, while the Igeo results indicated that Cr, Mn, Ni and Zn were strongly contaminated in the sediments. The main sources of pollutants in the area were mining, wastewater/sewage and agricultural discharges. This may pose a serious threat to the aquatic biota and potential human health risk. It is therefore recommended that proper management strategies should be taken to minimize the impact of these metals on the river.