Exploring river pollution based on sediment analysis in the Upper Tisza region (Hungary)

Area of Science:

• Environmental Science
• Geochemistry
• Ecotoxicology

Background:

• The Upper Tisza region experienced significant metal contamination in 2000 from a mining accident in Romania.
• Understanding the long-term fate and detectability of this contamination in aquatic sediments is crucial for environmental management.

Purpose of the Study:

• To assess the persistence of metal contamination in oxbow lake sediment cores 15 years after the 2000 Tisza River cyanide spill.
• To analyze the vertical distribution of elemental concentrations and determine the extent of ongoing pollution.

Main Methods:

• Sediment cores were collected from five oxbows in the Upper Tisza region.
• Elemental concentrations (Cu, Cr, Ba, Fe, Mn, Pb, Sr, Zn) were measured using microwave plasma-atomic emission spectrometry (MP-AES).
• The Pollution Index (PI) was calculated to quantify sediment enrichment by metals.

Main Results:

• The 2000 contamination event was identifiable in the vertical sediment profiles.
• Copper (Cu), lead (Pb), and zinc (Zn) contamination from the 2000 spill was detected at high or moderate levels.
• Manganese (Mn) showed moderate contamination across all sites, while iron (Fe) and strontium (Sr) levels varied.
• Barium (Ba) and chromium (Cr) contamination levels were generally low.

Conclusions:

• Sediment cores serve as valuable archives for tracking historical pollution events.
• The 2000 mining spill's impact is still evident in the Upper Tisza oxbows, indicating significant metal persistence.
• Contamination of the Tisza River from the Romanian mining area appears to be continuous and ongoing.