Evaluating and mapping the environmental risk of soil heavy metals using by contamination indexes in the Tehran south farms

Document Type : Research Paper


1 p

2 Khuzestan agricultural and Natural resources Research

3 soil and water research institute


Heavy metals are a group of elements which are known as contaminants at concentrations more than standard limits. Contamination indices made it possible to compare between the contamination made by different heavy metals due to human activities. So, this study aimed to evaluate and map the spatial distribution of environmental risk of heavy metals using by contamination indices in farm lands of south of Tehran. In this study from the 2000 hectares of the farms around Firooz Abad stream in Tehran south, 175 soil samples were selected with 300 meters intervals. Inverse distance weighting method was used to map in terms of geoaccumulation Index, contamination factor, pollution load index and environmental risk potential index. The most average values of geoaccumulation index and contamination factor were related to lead. The results indicated that %86 of the studied soil samples were contaminated to lead in terms of expressed indexes. The maps of pollution load and environmental risk potential indexes (comprehensive indexes for soil contamination to all heavy metals) illustrated that over area was polluted. According to environmental risk potential index, about %98 of studied land area (1857 hectares) were in noticeable risk class and about %2 of land area (33 hectares) were in high risk class.


Volume 70, Issue 4
February 2018
Pages 757-868
  • Receive Date: 29 April 2017
  • Revise Date: 14 January 2018
  • Accept Date: 21 October 2017
  • First Publish Date: 22 December 2017