Integrated Assessment of Soil Contamination and Ecological and Human Health Risks at the Morava Thermal Power Plant Complex: A Three-Year Case Study

This three-year case study integrated the results of annual soil-monitoring campaigns conducted in 2022–2024 at 17 predefined locations within and immediately surrounding the Morava Thermal Power Plant Complex, Serbia. We analyzed surface soil samples (0–30 cm) for physical and chemical properties, metals and metalloids, and selected organic pollutants. Contaminant concentrations were evaluated relative to national regulatory thresholds, while potential ecological risk and outdoor worker human health risk were assessed using the potential ecological risk index (RI), Hazard Index (HI), and total carcinogenic risk (TCR). Soil properties and total contaminant concentrations varied considerably among the monitored locations. Regulatory classification identified Ni and Cd as the most widespread concerns. Ni exceeded the applicable limit value at all 17 locations in each campaign, including three remediation-value exceedances in 2022 and one in 2024. Cd exceeded the limit value at 17, 11, and 16 locations in 2022, 2023, and 2024, respectively, without exceeding the remediation value. RI ranged from 210.02 to 963.08, indicating moderate to very high potential ecological risk, and was driven primarily by Cd and Hg. Aggregate HI values ranged from 0.211 to 0.484 and remained below the screening threshold of 1 at all locations. In contrast, TCR ranged from 5.98 × 10−5 to 2.12 × 10−4 and exceeded the target benchmark of 1 × 10−6 at every location in all three campaigns. Arsenic accounted for more than 94% of TCR, while the conservative estimate obtained by applying Cr (VI) toxicity parameters to total Cr represented the principal secondary contribution. The different assessment approaches identified distinct contaminant priorities and therefore provided complementary rather than interchangeable information. The results support continued monitoring, targeted investigation of locations with elevated regulatory or risk indicators, direct chromium-speciation analysis, and integration of soil monitoring with groundwater, drainage-water, bioavailability, and effect-based assessments to support future reclamation and environmental management.