Evaluation of the Pollution by Toxic Elements around the Small-Scale Mining Area, Boroo, Mongolia

Abstract

The objective of this study is to investigate the contamination levels of toxic elements (TEs) in the vicinity of the small-scale mining Boroo area, Mongolia. Samples of surface soil, ground water and human hair were collected around the gold washing or milling places, grassland and village areas. After appropriate preparation, all samples were analyzed for major and toxic elements (TEs) by Particle-Induced X-ray Emission Spectrometry (PIXE). Soil texture, conductivity (EC), pH, total organic carbon (TC) and nitrogen (TN) contents were also measured. The enrichment factor (EF) was estimated to assess the level of the contamination and the possible anthropogenic impact in soils from the mining activity. The EF soil for Cu, As and Pb were in the highest values around gold washing place, indicating that around mining area surface soils were highly enriched by those elements. The Mn, Fe and Ni concentrations of drinking waters exceed the WHO values. The mean concentrations of Ca, Ti, As and Sr were higher in hair of Mongolian miners than in the hair of normal people in Japan, Mongolia and Philippines. These results indicate that the area around gold washing or milling could be the main contamination sources of As and other toxic elements (TEs) in the surface soil samples.