• Lead;
  • Iran;
  • Streambed sediment;
  • Concentration;
  • Trace element


Streambed-sediment samples were collected in the Sarbaz River Basin in Sistan and Baluchestan Province, east of Iran, to characterize the occurrence and distribution of lead in natural and anthropogenic sites of the basin. During June and July 2008, stream sediment was collected at 30 sites, and the samples were analyzed for lead. Sites sampled represented agricultural, mining, mixed, rangeland, recreation, and residential land uses and background conditions. Lead was detected in all collected stream-sediment samples of the basin. Most of the lead concentration was associated with the smaller part of the 2 grain-size fractions: 2000 to 43 μm and <43 μm. The range in concentrations of lead at urban/rural sites generally was higher than the range of concentrations at nonurban/rural sites. Sediment from 2 distinctly different rock types in urban/rural areas were not significantly different (t = 0.1330, p = 0.8955) for concentrations of lead. Concentrations of lead were not significantly different (t = 0.0845, p = 0.6865) between main-stem sites and tributary sites. Concentrations of lead exceeded established sediment-quality guidelines for adverse effects on aquatic biota at most of the urban/rural sites in the study area.