The determination of the total metal content can be useful for sediment characterization However, it does not provide enough information on the bioavailability or toxicity of metals. In sediment, metals can be found in different chemical species, and depending on the species in which it is found, bioavailability, mobility and its toxicity can be determined. Sediments concentrate metals from aquatic systems and represent a suitable and strategic means for conducting pollution monitoring studies. Heavy metals are among the most common pollutants and their ecological impact is due to their toxicity, high persistence and non- degradability in the environment. The most important anthropogenic activities are the agricultural, industrial, manufacturing, and mining activities. Contamination of sediments by heavy metals can occur naturally or anthropogenically. Sediments play an important role in transportation of nutrients, metals and other pollutants through river systems to the oceans and seas of the world. Sediment deposition occurs by entrainment of both organic and inorganic particles.

Sediments are the result of the deposition of particles that bring along material of rocks and minerals, heavy metals, organic matter, among others. Keywords: Metals Bioavailability Sediments Bacanuchi and Sonora rivers The quality criteria comparisons (LEL and SEL) indicate both rivers are contaminated by metals and represent a danger to biota, due to the high metal mobility and bioavailability. The Bacanuchi river showed moderate to strong contamination of Cu and Pb. Values of Igeo were classified as non-contaminated to moderately contaminated. EF showed an anthropogenic enrichment in both rivers for Cu, Cr, Mn, Ni, Pb and Zn, mainly derived from the mining activity. The order of mobility and/or bioavailability of metals was: Mn>Cu>Ni>Pb>Zn>Fe>Cr. Metal concentrations in geochemical phases exhibited the following order: residual>Fe/Mn oxides> exchangeable>organic matter. The evaluation of heavy metal contamination was performed using Enrichment Factor (EF) and Geoaccumulation index (Igeo). BCR sequential extraction was performed to determine geochemical phases in which metals are found. These rivers were affected by a spill caused by the mining activity of the region, which is considered the most important ecological disaster in the modern history of Mexico. DOI: 10.19080/IJESNR.2004Ī study of the Sonora and Bacanuchi rivers was conducted to assess the mobility and bioavailability of heavy metals. Study of Heavy Metal Pollution in Arid and Semi-Arid Regions Due to Mining Activity: Sonora and Bacanuchi Rivers. *Corresponding author: A Gomez-Alvarez, Department of Chemical Engineering and Metallurgy, University of Sonora, 83000 Hermosillo (Sonora) Mexico, Tel:+52 2592106 Fax: +52 (662) 2592105/2592107 Email: to cite this article: MG León-García, D Meza-Figueroa, J Valenzuela-García, M Encinas-Romero, A Villalba-Atondo, K Encinas-Soto, A Gómez-Álvarez. Luís Encinas and Rosales, Hermosillo, MéxicoĢDepartment of Geology, University of Sonora, Luýs Encinas and Rosales, Hermosillo, MéxicoģDepartment of Scientific and Technological Research, University of Sonora, Luis Encinas and Rosales, Hermosillo, México Research Article Study of Heavy Metal Pollution in Arid and Semi-Arid Regions Due to Mining Activity: Sonora and Bacanuchi Rivers GJ León-García 1, DM Meza-Figueroa 2, JL Valenzuela-García 1, MA Encinas-Romero 1, AI Villalba-Atondo 3, KK Encinas-Soto 1 and A Gómez-Álvarez 1*ġDepartment of Chemical Engineering and Metallurgy, University of Sonora, Blvd.

Environ monit assess impact factor 2013