Contamination of Zn, Pb and Cd in topsoil in Katowice-Szopienice (southern Poland) as a result of 180 years of metal smelting: environmental implications

Abstract

The world's longest continuously operating Zn and Pb smelters were based in the Katowice-Szopienice area, for 180 years. In the current study, Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDS), X-ray diffraction (XRD), and Atomic Absorption Spectroscopy (AAS) were used to examine recently collected topsoil samples from 0–10 cm depth. AAS studies revealed extremely high concentrations of heavy metals in the topsoil. Zinc, Pb, and Cd concentrations exceeded 10,000, 4,650 and 204 mg kg–1, respectively. The metals are mostly derived from sulphides, oxidized Zn-Pb ores, smelter slags, and emissions from metallurgical processes, such as metal alloy production. The abundance of each group of minerals depends on the type of industrial activity in the area (Zn or Pb metallurgy, metal rolling mills, smelter waste dumps, etc.). Sources of potentially toxic Pb, Cd, As and Sb are primary and secondary mineral assemblages. The largest part of Zn and Pb is bound in minerals that are products of base-metal ore weathering and in synthetic silicate minerals formed during Zn smelting. Smithsonite, hemimorphite and cerussite are among the most common secondary minerals. Metals from carbonate and silicate minerals are mobilized more slowly. Leaching tests showed that there is a risk of transfer of toxic Cd ions into soil solutions (>20% of Cd is present in the ion-exchange fraction). Our study will be useful for planning reclamation and revitalization efforts aimed at minimizing the adverse impact of metal-bearing minerals on the environment