Identification of Environmental Risk Areas Using Pollution Indexes and Geographic Information Systems

Abstract

The objective of this study was to demonstrate the usefulness of geographic information systems (GIS) and pollution indices to identify environmental risk areas affected by metals. The study area was located in the city of Murcia and its surroundings (SE Spain). The concentrations of Cr, Zn, Cu, Pb, Mn, Ni and Cd in 221 soil samples were determined, and five pollution indices calculated. After an analysis of each index and a comparison among them, the pollutant load index (PLI) was selected for the following reasons: (1) it provided a good spatial distribution of the areas of highest risk, (2) all metals contributed in a similar way to the index value, and (3) the index includes background concentrations in its calculation, which allowed to determine the level of metal enrichment. After selecting the index, GIS was used to create a spatial distribution map adjusting the parameters to obtain an adequate delimitation of the areas with the highest environmental risk. As a result, eight areas were identified. Therefore, the calculation of pollution indices and subsequent integration into a GIS is an appropriate and effective tool for rapid identification of environmental risk areas by presence of metals.