Establishing a baseline for environmental risk assessment: a systematic review of the disposal of mining tailings in the crossborder region Romania - Serbia.

The cross-border region between Romania and Serbia has been deeply affected by decades of mining activities, resulting in significant environmental degradation and public health risks. By consolidating data from peer-reviewed studies, government reports, and environmental monitoring datasets, this systematic review and quantitative synthesis establish a critical basis for the environmental risk assessment from mining activities as a result of tailings storage in the Romania-Serbia cross-border area, with a focus on the Moldova Nouă (Romania) and Bor (Serbia) mining areas. Following PRISMA 2020 methodology, 22 studies were systematically identified and included in the quantitative synthesis. The review identifies the main routes of contamination, quantifies the levels of pollutants such as heavy metals (copper, lead, zinc, arsenic) and assesses the socio-economic impact, providing a framework for setting a baseline for future monitoring and remediation strategies. Statistical re-analysis of aggregated data indicated severe pollution for lead in Moldova Nouă (Geoaccumulation Index, Igeo = 4.32, "strong to extremely polluted") and significant arsenic contamination in Bor (Igeo ≈ 3.5). Copper showed moderate pollution (Igeo ≈ 2.4) in Moldova Nouă. The proposed baseline, adopted from Romanian national standards (Order 756/1997), includes soil metal concentration thresholds (Cu: 20 mg/kg d.w., Pb: 50 mg/kg d.w.), a Water Quality Index (WQI) below 50 (indicating good quality), and an occupational morbidity rate below 5 cases per 1000 workers. The results highlight the urgent need for bilateral cooperation to manage crossborder pollution and reduce occupational morbidity through integrated interventions.