lead contamination and pollution indexes in roadside soil in tehran, iran

Background and purpose: in the process of rapid urbanization and industrialization indeveloping countries, environmental pollution is a major concern. one of the fastest growingproblems of environmental pollution is an excessive intake of lead in urban soils. leadconcentrations in urban soil may result from human activities such as vehicle emissions andindustrial activities. this study aimed to determine of lead contents in roadside soil samples intehran city, iran.materials and methods: one of tehran municipality rsquo;s subsections was selected for thecollection of 21 samples from seven stations along a main urban highway. in this study, sampleswere taken over a period of 3month in the dry season. sampling was performed in the order of100 m long, perpendicular to the roadside at 0, 50, and 100 m from the road. lab measurementswere performed on the physical and chemical properties of samples. the extraction wasperformed using four kinds of acids (hcl, hno3, hf, and hclo4).results: lead concentrations were measured by a spectrophotometer with an averageconcentration of lead in soil samples of roadsides standing at 112.21 part a million (ppm), andthe average lead bioaccessibility at 14.19 ppm.conclusion: lead concentrations showed a linear decrement in proportion to the distance fromcenter line of the road. human cultural activities were sources of lead pollution by examine soilcontamination indexes.