Soil contamination near a former Zn–Pb ore-treatment plant: Evaluation of deterministic factors and spatial structures at the landscape scale

Abstract

Historical soil contamination within a 3 km radius of a former ore treatment plant was evaluated. A total of 247 topsoil samples were collected in a stratified random sampling design taking into account three factors: land use (LU), soil type (ST) and wind direction (WD). Concentrations of trace elements (Cd, Co, Cr, Cu, Ni, Pb and Zn) and major elements (Ca, Mg, K, Fe, Al, Mn) as well as various soil properties (pH water , pH KCl , TOC and N) were measured. Total Cd, Pb and Zn concentrations were higher than typical background values. Enrichment factors for these three metals were, respectively, 260, 77.4 and 35.5. Principal component analysis (PCA) and factor analysis segregated anthropogenic contamination as a premier factor in influencing concentrations, followed by a second lithogenic factor. The anthropogenic origin of substantial contamination was confirmed through mapping of sample locations relative to contaminant sources. Factor 1 (26.5% of the variance) impacts a large area around the contaminated site and is also indicative of WD influence. Factor 2 (23.9% of the variance) is naturally linked to the local lithology and geology. LU and soil fertility are, respectively, represented by factor 3 (16.5% of the variance), which is linked to pH, and factor 4 (9.3% of the variance), related to organic content. The significance of landscape factors in the spatial distribution of metallic trace elements (MTE) was assessed with an ANCOVA using "distance to the source" as a covariate. Results of the analysis support the hypothesis that Cd, Cu, Pb and Zn concentrations are mainly driven by anthropogenic factors, specifically historical industrial activity at the former ore treatment plant. The ANCOVA also provides a means to quantify the impact of LU and ST as well, particularly on MTE availability in soils. The presence of MTE in soil poses known, and potentially significant, risks to both human health and the environment.

Distribution of potentially toxic elements (PTEs) in tailings, soils, and plants around Gol-E-Gohar iron mine, a case study in Iran

“…The high contents of As, Co, Cu, Fe, Mo, Ni, and V in Tailings and topsoil in the Near area in relation to those detected in the local baseline clearly indicate contamination by fallout dust coming from the ore processing plants and tailings piles. Liénard et al (2014) concluded that severe contamination of topsoil by Cd, Cu, Pb, and Zn within a 3-km radius circle surrounding stacks of a former Zn-Pb ore treatment plant of the Sclaigneaux calaminary site in Belgium is probably driven by anthropogenic factors, specifically historical industrial activities and subsequent atmospheric deposition. Li et al (2015) also reported that Pb/Zn smelting and resulting dust fallout have led to significant contamination of the local topsoil by Zn, Pb, Cd, As, Sb, and Hg in a town in Yunnan Province of China.…”

Safety of Potato Consumption in Slovak Region Contaminated by Heavy Metals due to Previous Mining Activity

“…Adsorption of heavy metals is also highly dependent on soil components that include silicate clays, organic matter, iron, aluminium, and manganese oxides [44,45]. The soil contents of Cd, Pb, and Ni are variable (e.g., northern Pakistan, southwestern China, Wallonia region of Belgium, and northwest of Iran: Cd 0.08-4.5, Pb 17.0-672.0, and Ni 0.46-103.0 mg kg −1 soil) depending on agroclimatic conditions [27,[46][47][48].…”

Assessment of soil metal distribution and environmental impact of mining in Katanga (Democratic Republic of Congo)

“…Aluminum was selected to be the reference value. Indeed, Al is the most common reference value used to calculate the EF (e.g., Bourennane et al, 2010;Liénard et al, 2014).…”