Distribution and Assessment of Trace Elements Contamination in Sediments of Conceição River Basin, Brazil

Lucas Pereira Leão,Hermínio Arias Nalini Júnior,Mariângela Garcia Praça Leite,Raphael De Vicq Ferreira Da Costa,Rita Maria Ferreira Fonseca

doi:10.3390/geosciences11060236

Lucas Pereira Leão, Hermínio Arias Nalini Júnior + Show 3 more

Open Access

https://doi.org/10.3390/geosciences11060236

Copy DOI

Abstract

The Conceição river basin, in Quadrilátero Ferrífero (Iron Quadrangle), Brazil, has a long mining history which dates back to the late 17th century, with large gold and iron mines. These activities may be associated with river sediment contamination by trace elements, which were evaluated in this paper by the enrichment factor (EF) and contamination factor (CF). Potential ecological risks, assessed by combining sediment quality control guidelines (SQCG) and potential ecological risk indexes (Er and RI), are presented. Anomalous values for As (92.5 mg·kg−1), Cd (22.49 mg·kg−1), Cr (2582 mg·kg−1), Cu (65.9 mg·kg−1), Pb (58.6 mg·kg−1) and Zn (133.4 mg·kg−1) are observed. The EF and CF indexes indicate contamination by Cd, Cr, Fe, Mn, Ni and Zn in at least one site, with the highest values for Fe and Mn downstream of the iron mines, and Cr and Ni close to the gold mines. According to the SQGC and Er, As, Cd, Cr, and Ni are the most probable to result in adverse effects on sediment-dwelling organisms in this study. The results of principal component analysis (PCA) indicate distinct lithological units as sources of the analyzed elements, which, associated with the indexes, made it possible for the first time to delimit and classify the high concentrations of some analyzed elements as contamination in the Conceição river basin.

Highlights

IntroductionCompared with naturally occurring metals, anthropogenic metals on sediments have high mobility, bioavailability, and adverse effects on aquatic organisms [2,3]
Compared with naturally occurring metals, anthropogenic metals on sediments have high mobility, bioavailability, and adverse effects on aquatic organisms [2,3]. In this context, understanding the spatial distribution of heavy metals, differentiating the human contribution, and determining possible ecological risks are essential for assessing the quality of sediments and protecting the aquatic environment [3]
The Pollution Load Index (PLI) for a sediment sample is calculated as the geometric mean of the concentration factors (CF) of metals [42], and environments with PLI > 1 are classified as polluted, while

Summary

Introduction

Compared with naturally occurring metals, anthropogenic metals on sediments have high mobility, bioavailability, and adverse effects on aquatic organisms [2,3]. In this context, understanding the spatial distribution of heavy metals, differentiating the human contribution, and determining possible ecological risks are essential for assessing the quality of sediments and protecting the aquatic environment [3]. Contamination Factor (CF) and Pollution Load Index (PLI). The PLI for a sediment sample is calculated as the geometric mean of the concentration factors (CF) of metals [42], and environments with PLI > 1 are classified as polluted, while.

Methods

Results

Conclusion