Antimony in the contaminated Site of El Triunfo, Baja California Sur, Mexico

Abstract

Antimony has properties similar to arsenic with some of its compounds toxic to humans. Therefore it is necessary to control the wastes accumulated by anthropogenic activities, such as mining, where it is in tailings to be released to the environment. According to the Environment Protection Agency, the maximum value in sediments is 11.2 mg Sb kg-1 and the Earth's crust average is 0.2 mg Sb kg-1. In this semiarid area, the drainage basin El Carrizal is impacted with wastes of an abandoned gold mine at the Mining District El Triunfo (MD - ET) which have tailings with 17,600 mg kg-1 of antimony. In the main dry river (arroyo), the Sb content is between 0.6 and 122 mg kg-1. This element is transported from the source throughout the fluvial basin to discharge into the Pacific Ocean. In the arroyo mouth we collected one sedimentary core and the sediment from dunes (28.6 - 45.7 and 6.43 - 7.74 mg Sb kg-1). This research concluded the antimony is enriched in this semiarid system, with Normalized Enrichment Factors severely enriched mainly in arroyo sediments close to the MD-ET.