# Assessment of contamination, mobility and application of selected technology-critical elements as indicators of anthropogenic pollution of bottom sediments

## TL;DR

This study explores how certain rare elements in river sediments can indicate human-caused pollution and their environmental risks.

## Contribution

The study identifies specific technology-critical elements as pollution indicators linked to mining and coal activities.

## Key findings

- Sediments showed high contamination by Sb, Ga, Tl, Cd, As, Zn, and Pb.
- Sb and Tl are linked to Zn-Pb ore mining, while Co, V, and Ge are linked to coal and fly ash.
- Sequential extraction revealed high mobility of Sb, In, and Tl from sediments.

## Abstract

The study investigates the potential of technology-critical elements (TCEs) in the bottom sediments of the Biała Przemsza River as indicators of anthropogenic activities. The mass fractions of TCEs: Ge, Ga, In, Tl, Sb and Te (and other elements) in the sediment were analysed by inductively coupled plasma mass spectrometry with the maximum mass fractions: 2.46, 25.6, 0.528, 27.7, 12.5 and 0.293 mg/kg, respectively. Distribution and identification of TCE sources were supported by statistical analysis (principal component analysis coupled with varimax rotation and hierarchical cluster analysis). Assessments of TCE contamination using the geoaccumulation index, pollution index, contamination factor, enrichment factor and the antimony-to-arsenic ratio highlighted the high contamination of bottom sediments by Sb, Ga, Tl, Cd, As, Zn, Pb and moderate contamination by Co, In and V. Distinct behaviour patterns were observed among TCEs, revealing Sb and Tl as potential indicators of Zn-Pb ore mining activities. Co, V, Ge and, to a lesser extent, Te emerged as promising indicators of coal and coal fly ash effluents. Sequential chemical extraction of TCEs showed that Sb, In and Tl had the highest mobility from sediments. The Risk Assessment Code calculations suggest, that in the Biała Przemsza River bottom sediments, there is an average risk of contamination by As, Tl and Mn. Soluble forms of Tl, Ge, Sb, Te and In were identified in descending order, indicating their bioavailability.

The online version contains supplementary material available at 10.1007/s11356-024-34377-5.