Assessment of trace metal distribution and contamination in surface soils of Amman, Jordan

الملخص EN

A total of 78 street dust samples were collected from four different localities (busy and main roads, industrial, tunnels and residential roads) located in the greater Amman area of Jordan.

After digestion, all samples were analyzed for their content of Pb, Cd, Zn, Cu, Cr, Co and Ni.

A profile for average street dust for Amman has been determined by taking average values for different areas.

The average concentrations of Pb, Cd, Zn, Cu, Ni, Co and Cr in busy and main roads were 270.5, 1.87, 350.7, 139.4, 66.0, 32.4, and 29.2 mg/kg, respectively.

Highest concentrations for Cu, Zn, Cr and Ni were observed in the industrial area, whilst maximum lead concentrations were observed in tunnels and busy roads.

Concentrations of Cd and Co did not show significant variations between the four categories and therefore presumably represent widespread usage and / or environmental dispersal of these metals.

Enrichment factor calculations indicated that Pb, Cu, Cd and Zn are highly enriched.

Fossil fuel combustion, traffic emissions, wear of brake lining materials, and several industrial processes are considered as major emission sources of these elements.

The extremely high levels of Zn in the industrial area and in busy roads were attributed to the extensive use of galvanized-iron roofing.

A multivariate statistical approach (Principal Component Analysis) was also used to define the possible origin of metals in dusts.