Potential ecological risk index for metals in a grazing area, Guasca, Cundinamarca

Abstract

The presence of metals in soils used for primary economic activities can negatively impact the environment and public health. This research identified soil contamination by heavy metals (Lead, Copper, Zinc, and Manganese) by examining physical and chemical properties (Phosphorus, Potassium, organic carbon, cation exchange capacity, pH, texture, and bulk density) of the area during the dry and rainy seasons of 2017. Composite samplings of soil were carried out in both seasons, in order to obtain a representative value of the soil in certified laboratories. Thereafter, through interpolation by means of the Kriging method, a spatial scale of metal concentrations was conducted. This led to the conclusion that the study area has an acceptable environmental quality (5.8-6.9) for its current use of grazing. Likewise, the area presents a medium level (75.37), pursuant to the Potential Ecological Risk Index (RI) for the dry season, and a very high risk (195.04) during the rainy season. These estimates are directly related to lead concentrations, introduced to the soil of the area by human development activities and by contributions of parent material to the soil surface layers, through natural processes of weathering.