Heavy Metal Contamination Degree of Soils Surrounding the Rehabilitated Dump of Oued Smar, Algeria

The present research was conducted to evaluate metal potentially toxic contamination of soils in the vicinity of rehabilitated dump (Oued Smar) of northern Algeria. Soil samples were collected from three surrounding sites and one rural site in Béjaïa, as a reference site and analyzed for six metals (cadmium, chrome, nickel, copper, lead, and zinc). Metal concentrations and distributions in different road verge zones (border, verge, and reference) were determined. Chrome concentration was the highest in the soil and ranged from 03.67 to 53.91 μg/g. Zinc concentration ranged from 13.78 to 14.88 μg/g, and lead concentration ranged from 13.96 to 20.62 μg/g. Nickel concentration was the lowest in the soil and varied from 9.06 to 10.74 μg/g. Though the levels of metals in soils were higher as compared to their natural background levels in Algerian soils as reference, the results of the analysis of metals extracted from the three soils showed that their concentrations were below the “critical trigger concentrations” of the contaminated soils. Several environmental parameters namely the pollution index, the geo-accumulation index, and the enrichment factor have been determined. These parameters show that the soils studied are exempt from any contamination by metals.