# Assessment of Heavy Metal Accumulation in Soils and Dominant Agricultural Crops in an Industrial Environment of Ridder, East Kazakhstan Region

## TL;DR

This study assesses heavy metal contamination in soils and crops near industrial areas in Ridder, Kazakhstan, finding high levels of metals and limited uptake in plants.

## Contribution

The study provides new insights into HM accumulation patterns in soils and vegetation under long-term industrial influence in East Kazakhstan.

## Key findings

- Soil concentrations of Zn, Cu, Cd, and Pb were extremely high, with Cd posing the highest ecological risk.
- Industrial zone vegetation consists of stress-tolerant species that accumulate heavy metals primarily in roots.
- Agricultural crops showed limited translocation of heavy metals to aboveground parts, indicating phytostabilization.

## Abstract

Mining and metallurgical activities are among the main sources of heavy metal (HM) contamination of terrestrial ecosystems and the creation of persistent technogenic pollution hotspots. This study aimed to provide a comprehensive assessment of the accumulation of zinc (Zn), cooper (Cu), cadmium (Cd) and lead (Pb) in soils and vegetation under conditions of long-term industrial impact in Ridder, East Kazakhstan Region. A total of 52 soil samples were collected from 0–5 cm and 5–20 cm depths at 26 sites, and 44 species of natural vegetation, as well as three dominant agricultural crops, were examined. Soil concentrations of Zn (4415 mg·kg−1), Cu (1177 mg·kg−1), Cd (179 mg·kg−1), and Pb (1996 mg·kg−1) were classified as extremely high. Cadmium contributed most to the potential ecological risk (Cd > Pb > Zn > Cu). The industrial zone’s vegetation cover was predominantly formed by stress-tolerant and ruderal species, including Artemisia vulgaris, Calamagrostis epigeios, Bunias orientalis, Dactylis glomerata, Convolvulus arvensis, and Urtica dioica. The agricultural crops (Helianthus annuus, Avena sativa, and Triticum aestivum) mainly accumulated HMs in their root systems, with limited translocation to their aboveground organs (TF < 1). This indicates the predominance of phytostabilisation mechanisms, and highlights the potential of locally adapted plants for managing contaminated areas.