Heavy Metals in River Sediments: Contamination, Toxicity, and Source Identification-A Case Study from Poland

Area of Science:

• Environmental Science
• Geochemistry
• Ecotoxicology

Background:

• Heavy metals (HMs) in river sediments pose ecological risks.
• Understanding their spatial distribution and sources is crucial for environmental management.

Purpose of the Study:

• To investigate the spatial distribution, contamination, ecological risks, and sources of six heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) in sediments of 47 Central European rivers.
• To assess sediment quality and potential toxic effects on aquatic biota.

Main Methods:

• Cluster analysis for spatial distribution.
• Moran I and Getis-Ord Gi* statistics for pattern and hotspot analysis.
• Principal Component Analysis (PCA) and Positive Matrix Factorization (PMF) for source identification.
• Geochemical indices and sediment quality guidelines for contamination assessment.

Main Results:

• One-third of rivers showed HM contamination; two-thirds had low concentrations.
• Spatial autocorrelation revealed a random HM distribution pattern.
• PCA identified point/non-point sources for Cr, Cu, Ni, Pb, Zn, and natural origin for Cd.
• PMF identified urban (Cu), agricultural (Zn), and industrial (Ni, Cr) pollution sources.
• No relationship found between land use and HM content.

Conclusions:

• While some rivers exhibit HM contamination, overall levels are generally low with dispersed patterns.
• Pollution originates from diverse sources, with specific metals linked to urban, agricultural, and industrial activities.
• Cd appears to have a predominantly natural origin, and land use is not a primary driver of HM content in these river sediments.