Estimation of the lead origin in agricultural land close to a mining activity due to the isotopic ratio ²⁰⁶Pb/²⁰⁷Pb

Due to the presence of lead (Pb) in different matrices such as soil, is very important to estimate its origin due to its impact on public health and food safety of products generated in agricultural areas close to mining activities. Determining the presence of Pb, As and Hg and the isotopic ratio ²⁰⁶Pb/²⁰⁷Pb as a fingerprint was the objective of this investigation. The collection of 10 samples and their treatment were based on the standards NMX-AA-132-SCFI-2016 and NOM-021-SEMARNAT-2000, the concentration of heavy metals (Pb, As an Hg) were analyzed by atomic absorption spectroscopy with flame and atomic absorption spectroscopy with hydride generator, based on EPA methodology: Method 3010-A and Method 7061-A. On the other hand, 4 isotopic relationships with inductively coupled plasma mass spectroscopy (Icp-Ms) were analyzed, being the most representative for the ²⁰⁶Pb/²⁰⁷Pb study. The average concentration for Pb, As and Hg were lower than those established by the NOM-147-SEMARNAT/SAA1-2004. From the calculation of the correlation between Pb-As-Hg a significant positive correlation of R₀ = 0.82 for Pb-Hg was obtained, and an isotopic ratio ²⁰⁶Pb/²⁰⁷Pb of 1.206 ± 0.003. Therefore, is estimated that the origin of Pb is due to mining activities that are carried out close to the study area. (Author)