Statistical Analysis of Heavy Metal Contamination in Urban Dusts of Arak, Iran

Present investigation was performed to provide heavy metal signatures of urban dusts and to evaluate potential sources in Arak, Markazi province. Twenty- nine samples of urban dusts were collected in Arak city. Then Pb, Cu, Ni, Zn, Cr, Hg and As concentrations were determined by using atomic absorption spectrophotometry. The results indicate that, in comparison with Iran soil, urban dusts in some of the area in Arak have elevated metal concentrations, except those of Ni, Zn, Hg and As. Correlation coefficient analysis, principal component analysis (PCA) and cluster analysis (CA) were performed and three main sources with corresponding cluster elements were identified: (1) Zn, Cr, Hg and As have soil and industrial sources; (2) Pb and Ni are mainly derived from industrial sources, combined with traffic sources; (3) Cu come mainly from industrial sources. Geoaccumulation index (Igeo), enrichment factors (EF) and contamination degree (Cd) were calculated, which in turn further confirms the source identification. Also, Igeo, EF and Cd give an insight of human influence degree of urban dusts.