Zoning of dust heavy metals in Arak plain using pollution indicators and geographic information system (GIS)

Dust is one of the biggest climatic and environmental hazards in the world. Metals are one of the complex components in atmospheric dust, which has become an environmental problem due to its non-degradable, and it leads to health risks for humans in populated and industrial area like Arak city. In this study, dust samples were collected by random sampling from ۳۰ stations. The samples were analyzed by inductively coupled plasma spectrometry (ICP-OES), with digestion of four acids (HF, HCl, HClO۴, HNO۳). Pollution indices (PI) and Integrated Nemerow Pollution Index (NIPI) were calculated for lead, zinc, copper, nickel and iron in the dust of Arak plain. Also, Geographical Information System (GIS) was used in order to present the spatial distribution map of metals pollution. The average concentration of Pb, Zn, Cu, Ni and Fe in dust samples was ۴۵.۵, ۱۰.۷, ۰.۴۷, ۳۰.۸ and ۰.۲۰۶ mg/kg, respectively. The results of calculation of PI, NIPI pollution indices and the spatial distribution and zoning map of elements also showed that the northeast, center, south and southwest areas of Arak Plain have more pollution than other places, which can be due to human activities such as the presence of many industrial factories. Pollutants are urban ringways with high traffic rates of heavy vehicles, urban areas with high population density and heavy traffic, rural areas with a concentration of agricultural land, and activities such as Arak Airport and Arak City Water Treatment Plant.