Document Type : Original Articles
Authors
1
M.Sc. Student of Environmental Pollution, College of Agriculture and Natural Resources, Yazd Science and Research Branch, Islamic Azad University, Yazd, Iran
2
Associate Professor, Department of Agroecology, Shahid Beheshti University, G.C., Tehran, Iran
3
Assistant Professor, Department of Agroecology, Shahid Beheshti University, G.C., Tehran, Iran
4
Assistant Professor, Department of Civil Engineering, Islamic Azad University, Khorramabad Branch, Iran
Abstract
South lands of Tehran are the main source of agricultural productions in which some kinds of vegetables, legumes, cereals and other crops are growing. This research measured and zoned heavy metal soil pollutionin 1500 ha of these cultivated fields south of the city of Tehran in Iran. In this study, 128 samples were collected using the systematic-random method from 64 areas at depths of 0-30 cm and 30-60 cm and the concentrations of cadmium, chromium, nickel, lead and zinc were measured. The parameters of pH, electrical conductivity, and phosphate were also recorded. Zoning maps were developed using the inverse distance weighted method. The results showed that concentrations of heavy metals, with the exception ofnickel, were higher at the shallower depth than at the lower depth. The zoning map shows that cadmium, chromium, lead and zinc occurred in greater concentrations in the northern areas and nickel in the southern areas. A comparison of these results with Iranian soil resource pollution standards indicates that the levels of chromium, nickel and zinc exceeded the standards in some parts of the study area.
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