HEAVY METALS IN SOILS AND SEDIMENTS IN LA VILLA RIVER BASIN-PANAMA

Abstract

The objective of this study was to determine the concentration of heavy metals in soils, sediments, organic fertilizers and agrochemicals that are commonly used for agricultural production within La Villa river basin, Herrera and Los Santos provinces, Panama. A total of 21 soil and sediment samples were taken during the rainy season (2016) and 20 during the dry season (2017) in the upper, middle and lower parts of the basin. Additionally, samples of fertilizers and agrochemicals commonly applied in the area. A totally random sampling was realized. The samples were digested according to EPA 3050B protocol. Analysis of variance and correlations were made to compare Cu, Zn, Mn, Fe, Cr, As, Ni, Cd, and Pb concentrations with soil properties. High Cu values were found in soil and Cu, Mn, Cr and As in the sediments, most of it attributable to anthropogenic action. Mostly used agrochemicals showed high Cu, Zn, Cr and Ni concentrations. Fungicides, specifically, showed very high Cu and Mn levels. Phosphorus fertilizers showed a high concentration of Cr, and high nitrogen levels were determined in nitrogen fertilizers. Permanent monitoring of production zones within La Villa river basin is recommended due to the constant use of agrochemicals and the accumulation of heavy metals in soils and sediments.