Characteristics of soil contamination by potentially toxic elements in mine areas of Mongolia.

Soil contamination by potentially toxic elements (PTEs), such as metal(loid)s, in mining areas was characterized on a nationwide scale in Mongolia to understand the contamination status throughout the country, according to mine types. Positive matrix factorization (PMF) analysis exhibited better classification and explanation of soil contamination according to ore types compared to conventional statistical analysis methods such as principal component analysis (PCA) and hierarchical cluster analysis (HCA). The results of PMF analysis for metal(loid) contents in 1425 topsoil samples collected from 272 mines illuminated four Factors, which primarily contributed to As (Factor 1), Pb, Zn, and Cd (Factor 2), Ni (Factor 3), and Cu and Cd (Factor 4) contaminations, respectively.