A comparative study of elemental pollution and health risk assessment in urban dust of different land-uses in Tehran's urban area.

Pollution levels of potentially toxic metals (PTMs) were studied performing enrichment factor, geo-accumulation index and ecological risk index. The most enriched elements which categorize as very high and extremely high enriched in different land-uses were in order of: commercial Cu (73.79)>Hg (66.55)>Pb (55.73)>Zn (46.15)>Cd (37.31); residential Pb (48.35)>Zn (34.79)>Cu (27.69)>Hg (22.96)>Cd (22.61) and industrial Zn (55.43)>Pb (51.52)>Cu (40.20)>Cd (26.29). In green lands sampling points, there weren't any elements with enrichment factor more than twenty. Based on the result of geo-accumulation index, commercial land-use appeared to be highly polluted with Cu, Pb and Zn. Residential land-use were highly polluted just in case of lead and industrial land-use were categorized as highly polluted in case of Zn, Pb and Cu. Hakanson's ecological risk index classified all of the land-uses except for green lands as very high ecological risk category. Factor analysis revealed that Cr, Mn, Ni, Fe and to a lesser extent Pb, Zn and As are from similar anthropogenic sources. Carcinogenic risk of Cr, Pb, As, Ni and Cd were found to be negligible for all land-uses for adult and children except for chromium in commercial land-use which exceed the safe level and need more attention in the future.