This study evaluated heavy metal (As, Cd, Cu, Zn) contamination levels in paddy field soils near 11 abandoned coal mines and conducted deterministic and probabilistic human health risk assessments centered on rice consumption pathways. In some areas, As exceeded the concern level (25 mg/kg) by up to 2.84 times (maximum 71.0 mg/kg), and Cd exceeded 4 mg/kg by up to 1.88 times (maximum 7.52 mg/kg). Based on the deterministic median (P50) criterion, the HI(Hazard Index) for adults was 2.38 and the CR(Cancer Risk)(inorganic As, iAs) was 3.7 × 10-⁴ (site exceedance rate: HI>1 was 99.8%, CR > 1 × 10^-4 was 99.6%). For children, the HI was 3.87 and the CR was 6.0 × 10-⁴, both higher than for adults. Probabilistic analysis showed that the P95 of HI and CR exceeded the criteria at multiple sites, with exceedance probabilities generally calculated at over 90%. Grading results indicated that the priority management category C grade accounted for 80.9%, confirming the urgency of management. The probabilistic assessment was limited to inorganic arsenic(iAs) and Cd (rice consumption pathway). Cu and Zn were excluded from quantitative risk calculation due to HQ(Hazard Quotient) < 1 and data uncertainty. This study confirmed that inorganic-Arsenic(iAs) dominates the risk in the rice pathway and proposed phased management strategies for priority sites, including soil As reduction and improvements in PF(Processing Factor) during cooking and milling processes.

Keywords: Abandoned coal mine, Deterministic assessment, Probabilistic assessment, Risk assessment, Priority management level, Sensitivity analysis