Spatiotemporal variation of PTE and evaluation of emergency response measures following a tailings leakage accident using partitioning -based PMF Coupled with GIS

Sudden environmental accidents frequently result in acute environmental damage, and despite emergency measures to minimize contamination, the long-term health risks and the control effects of these measures remain uncertain. This study collected 432 soil samples from the accident-affected, agricultural, and mining areas eight years after the tailings leakage and compared them with 27 post-accident samples. By employing a partitioned PMF Combined with GIS Mapping and health risk assessment models, we systematically analyzed the spatiotemporal dynamics of farmland risks before and after the antimony tailings reservoir leakage, evaluated the long-term effectiveness of emergency measures, and identified priority control factors for targeted remediation. Compared to pre-spill levels, the content of Sb, Hg, and As in farmland of each area was significantly decreased; the sources of PTE changed from tailings spill (29.21%), natural background (32.98%), and agricultural activities (41.1%) to diversified sources dominated by natural background. The health risk assessment showed ingestion as the main exposure pathway; after eight years, the health risk from accidental spillage decreased to an acceptable level, with all four sources of risk accounting for about 25%; and the accident-affected area’s cancer risk dropped from an unacceptable 1.02E-04 to an acceptable 5.05E-05, matching levels in the mineral impact and normal agricultural areas. Study results indicated: emergency measures implemented after the spill were effective in blocking the spread of pollution; Agricultural activities are the main source of As, contributing significantly to health risks, and priority should be given to controlling, and partitioning-based PMF provides more accurate source resolution results than large-scale PMF.