Pollution Level, Ecological Risk Assessment and Vertical Distribution Pattern Analysis of Heavy Metals in the Tailings Dam of an Abandon Lead–Zinc Mine

Tailings dams in mining areas frequently experience the phenomenon of haphazard dumping and stacking a large amount tailings waste. Under influence surface runoff groundwater infiltration, heavy metals from waste can migrate to surrounding underground soil, resulting extensive metal pollution. To analyze pollution level ecological risk an abandoned lead–zinc mine dam, this study first employed X-ray fluorescence analysis determine vertical distribution patterns with depth. Then, levels were analyzed based on Nemerow comprehensive index geoaccumulation index. Subsequently, was further assessed using potential (PER) Finally, sources hazards investigated. The results reveal that (1) pollutants are identified as lead (Pb), zinc (Zn), copper (Cu) arsenic (As), displaying enrichment at interface layer between reclaimed zone highest concentrations; (2) degrees each follow order > deep zone, for four decreasing Pb Zn As Cu; (3) after considering toxic effects metals, remains consistent ranking levels, contribution PER changes Cu, corresponding average Eri values 913.928, 416.900, 96.462 47.998, respectively; (4) originates ore extraction, poses risks public water security resources.