The Spatial Distribution of Pb, Cd, Zn, and Cu in Agricultural Roadside Soils

The primary objective of this study was to characterize the roadside agricultural soil samples from the Bani Kenanah District, North Jordan, in terms of heavy metal concentrations and soil characteristics. Samples were collected from different sites, at different depths, and at variable distances from the road starting from June 2004 to December 2004. The concentrations of heavy metals were measured by atomic absorption spectrophotometry. Samples were separated into seven physical fractions < 90, 90-106, 106-125, 125-200, 200-250, 250-1000, and 1000-2000 mu m to investigate the relationship between metal content and size fraction. The overall trend of heavy metal variations with particle size was that as sizes increase, concentrations decrease. The Pb, Zn, Cd and Cu profiles in soil demonstrated high concentrations in the top layer, 0-4 cm, but fall rapidly with increasing soil depth.