Analysis of Arsenic, Lead and Mercury in Farming Areas with Mining Contaminated Soils at Zacatecas, Mexico

Abstract. This study was conducted in order to identify the concen-tration of heavy metals (As, Pb & Hg) in contaminated soil in the county of Guadalupe, Zacatecas in order to have elements for deci-sion making by authorities and to identify exposition routes and fur-ther research activities to evaluate and reduce environmental and health risks in the site. Analysis were developed using EPA methods: SW 846: 3050B/6010B for arsenic and lead (FLAAS); and EPA SW 846: 7471A for total mercury (CVAAS). Compared to a recommend-ed concentration in soil of 20 mg/kg for arsenic and mercury and 100 mg/kg for lead (PROFEPA Interim Criteria of 2001), the concentra-tion of heavy metals was found to be up to 8 times higher for the met-als analyzed. With this information a dispersion model was run in order to get iso-concentration curves and to establish risk zones. From the data, two hot spots were identified (towns of La Zacatecana and Osiris) where mercury, lead and arsenic total concentration is higher enough to justify future speciation studies to evaluate the risk to the population within the area