Evaluation of the Sediment Quality of the Suches River Using Multivariate Analysis Methods

Abstract

The intensification of the artisanal mining activities generates alterations on the environmental components of the upper zone of the Suches basin. The pollution evaluation due to heavy metals is relevant because these are transported by sediments through bodies of water. In this study, sediment samples have been collected in five sampling sites of the Suches River throughout the span of five months and the concentrations of Chromium (Cr), Copper (Cu), Nickel (Ni), Lead (Pb) and Zinc (Zn) were determined through the Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The sediments pollution was evaluated by comparing to regulations, the calculation of the geochemistry pollution index and the application of multivariate statistical methods. The application of the analytical methods gave the following decreasing order of concentrations, Zn > Ni > Cr > Cu > Pb with values below that is stipulated by the Canadian Sediment Quality Guidelines (ISQG). Igeo revealed that the Cr and Pb values are in the unpolluted class in all the sampling sites, except for PM1 where Pb belongs to the unpolluted to moderately polluted class. Cu and Zn show moderate pollution, while Ni is in the moderately to heavy polluted class. Similarly, Ni presents a strong association with Cr and Zn. The factor analysis reveals two principal components (PC): Cr, Ni and Zn (PC1) and Cu y Pb (PC2). It is concluded that the contamination by heavy metals in the superficial sediments of the Suches River has a natural and anthropogenic origin.