Evaluation of soil pollution caused by waste accumulation from an abandoned gold mine 50 years ago in La Planta, San Juan, Argentina

HEREDIA, BELÉN; TAPIA, RAUL; RIZZO, PEDRO; YOUNG, BRIAN JONATHAN; ROQUEIRO, GONZALO

Congreso; SETAC Latin America 14th Biennial Meeting; 2021

Metal accumulation is the main soil pollution caused by abandoned gold mines. Metal(loid)s are not biodegradable and have high persistence in the environment. The objective of this study was to evaluate the degree of contamination generated by mining waste in La Planta, San Juan, Argentina. Ten soil samples were randomly taken at two sampling sites: contaminated (S1) and reference sites (S2). A physicochemical characterization was carried out. Total, mobilizable and soluble concentration of Cu, Cd, Zn, and As was determined. The Geoaccumulation Index (Igeo), Contamination Factor (CF) and Contamination Degree (Cdeg) were calculated to know the pollution generated by mining waste. Total concentration of metal(loid)s was contrasted with guideline values for residential and agricultural use (Argentine Law no. 24,051). An acid pH (=3) was recorded for S1 and slightly alkaline pH (=8) was recorded for S2. EC was 8 times higher in S1, reaching a maximum value of 41.2 mS cm-1. Essential nutrients were less concentrated in S1. Total concentration of Cu, Cd, Zn, and As was statistically higher in S1 (p0.7; p-0.7; p