Risk assessment using IEUBK model for the N aica mine tailings

Abstract Mexico has a long history of mineral extraction, during which limited environmental regulations allowed the accumulation of toxic waste near communities, primarily in rural or undeveloped areas. Some of these toxic substances, such as lead, pose significant risks to vulnerable populations, particularly children aged 0 to 7 years. In Naica, children represent 15.78% of the total population; this age group is especially susceptible to health issues related to lead exposure, including neurocognitive and developmental disorders. Systematic soil sampling was conducted in areas affected by mining waste, and the concentration of lead at each sampling point was determined through chemical analysis. Based on these results, three contamination scenarios were proposed: Scenario A (85.085 mg/kg), Scenario B (826.892 mg/kg), and Scenario C (4157.281 mg/kg). The Integrated Exposure Uptake Biokinetic (IEUBK) model was used to estimate blood lead levels (PbB) corresponding to each scenario. The model predicted PbB values of 20.651 μg/dL for Scenario B and 52.392 μg/dL for Scenario C, both exceeding the blood lead threshold of 10 μg/dL established in NOM‐199‐SSA1‐2000 and supported by literature as the level at which adverse health effects begin in children, pregnant, and lactating women appear. To mitigate these risks, we recommend immediate dust control measures, such as the application of chemical stabilizers or capping of the tailings, alongside the implementation of a continuous pediatric blood lead monitoring program in Naica.