ECOLOGICAL RISK AND CONTAMINATION LEVELS WITH LEAD AND ARSENIC IN AGRICULTURAL SOILS OF YANGAS, PERU

Anaya-Raymundo M.A.; Luna-Huamán M.S.; Blas-Montenegro L.P.; Ruíz-Janje A.; Sánchez-Rojas J.; De la Cruz Cámaco D.P. · Ciencia del Suelo (2026) · DOI: 10.64132/cds.v44i1.968

Resumen

This study evaluated lead (Pb) and arsenic (As) contamination and ecological risk in agricultural soils of Yangas, Peru. Soil samples from three plots were collected at two depths (0–20 and 20–60 cm) to quantify metal concentrations, assess their relationships with edaphic properties [pH, soil organic matter (SOM), cation exchange capacity (CEC)], and estimate ecological risk using contamination factors (CF), geoaccumulation indices (Igeo), and potential ecological risk indices (RI). Results showed Pb and As concentrations ranging from 24.22 to 32.69 mg kg-1 and from 20.82 to 31.00 mg kg-1, respectively, all below Peruvian environmental quality standards. Both elements exhibited a homogeneous vertical distribution, indicating stable retention and a predominantly geogenic origin. Soils showed a neutral to slightly alkaline pH (6.58–7.65), low SOM content (1.52–2.58%), and high CEC (21.70–51.76 cmol(+) kg-1) likely driven by illite- and smectite-dominated clay mineralogy. Correlation analyses revealed site-specific dynamics: whereas As correlated positively with pH and CEC in surface layers of plot 1, a negative As–CEC correlation was observed in subsurface layers of plot 3, suggesting variable retention mechanisms linked to competitive anion exchange or mineralogical heterogeneity. Based on ecological risk assessment, As exhibited high contamination factors (CF: 10.27–13.20) despite a low potential ecological risk index (RI: 117.11–147.18). Although current levels comply with regulatory limits, elevated As risk indices deserve continuous monitoring. Strategic organic amendments, pH stabilization, and continuous monitoring are essential to prevent contaminant mobilization and ensure long-term agricultural sustainability and food safety in this hydrogeologically vulnerable region of the middle Chillón River basin.

Instituciones: Universidad Tecnológica del Perú; Universidad Católica Sedes Sapientiae