Background level of indium and gallium in soil with special reference to the pollution of the soils from zinc and lead smelters

Abstract

Abstract The mean and range of indium content in unpolluted soils (Humic Andosols, Eutric Fluvisols, and Mollic Gleysols) was found to be 0.037 (0.016–0.078) μg/g dry wt. In soils polluted by common heavy metals, elevated values of indium up to 1.92 μg/g dry wt were observed together with an increase of cadmium, zinc, and lead. In contrast to indium, gallium content in polluted soils was nearly the same as that in unpolluted soils throughout the profiles. The mean and range of gallium content in all unpolluted and polluted samples was 14.2 (12.8–16.3) μg/g dry wt. The indium and gallium contents in 4 Canadian reference soils were also analyzed.