Analysis of environmental issues at Villa de la Paz-Matehuala-Cerrito Blanco, San Luis Potosi

The soil of Villa de la Paz and Matehuala, in San Luis Potosi, Mexico, is contaminated by heavy metals by the mining and metallurgical industries, respectively. Arsenic contamination impacted shallow groundwater. Groundwater contamination reached Cerrito Blanco, where groundwater is used for recreational activities and irrigation. The area of interest (Villa de la Paz, Matehuala and Cerrito Blanco) has been studied to determine the impact on soil, water, and the health of the population. In this paper, a syste-matic search of the available published literature was carried out. The literature was managed and evaluated according to the methodology proposed by the EPA in 2012 according to soundness, applicability and utility, clarity and completeness, uncertainty and variability, and evaluation and review criteria. The studies that approved these evaluation criteria were used to analyze and syn-thesize the information. The study of the area of interest began 25 years ago. Soil contamination and Pb and As exposure were found in Villa de la Paz due the presence of the mining industry. Additionally, high concentrations of As were found in shallow groundwater in Matehuala, which reaches Cerrito Blanco through a qanat. While soil contamination is mainly attributed to the mining industry, groundwater contamination is attributed to the metallurgical industry, where the mobility of As present in the soil is controlled by dissolution/precipitation processes of metallic arsenates. Arsenic contamination decreases from 91.5 mg/L of As to 11.2 mg/L along 1.3 km, likelny due to dilution and natural attenuation via capillary rise of groundwater. The last process is interesting to study in greater depth, as well as the continuity of the research that deals with the remediation of soil and groundwater. Being a site with soils highly contaminated with As, rich in Ca (semi-arid environment) and low concen-trations of iron oxyhydroxides, the information generated up to now can provide an opportunity to replicate the methods used in other sites with similar characteristics.