Impact of a zinc processing factory on surrounding surficial soil contamination

• Published in: Journal of geochemical exploration 2017-01, Vol.172, p.142-150
• Main Authors: Dumoulin, D., Billon, G., Proix, N., Frérot, H., Pauwels, M., Saumitou-Laprade, P.
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemical Sciences; Continental interfaces, environment; Earth Sciences; Geochemistry; Metal mobility; Sciences of the Universe; Soil pollution; Speciation; Zinc smelter
• ISSN: 0375-6742; 1879-1689
• DOI: 10.1016/j.gexplo.2016.10.005

Zn smelting plants located at Auby (Northern France) have strongly polluted the surroundings through dust emissions, storage of ores and slag without strong environmental concerns. Although highly contaminated surficial soils have been removed in the private and public gardens to safeguard health of the inhabitants, one small public area, called the Peru Park, has not been treated because of the presence of peculiar calamine grasslands. Our investigations in the soils of this park clearly evidenced a very strong contamination by several metals with concentrations up to 21,000mgkg−1 for Zn, 3500mgkg−1 for Pb and 160mgkg−1 for Cd. Additionally, the mobility of these metals is important in soils and increases with the pollution level. In the pore waters of strongly polluted zones, our findings are more contrasted with high concentrations of dissolved Zn (3.6–32mgL−1) and to a lesser extent Cd (0.02–0.25mgL−1), whereas dissolved Pb remains at low concentrations (0.0001–0.021mgL−1) and, according to calculations, is quite exclusively bound to humic substances. Finally, this study obviously underlines that this severe pollution and the high mobility of Zn and Cd could strongly impact the surficial aquifer and the trophic chain present in this area. •Soil in the Peru Park is highly polluted: up to 0.016% (Cd), 0.35% (Pb), 2.1% (Zn).•The pollution is very heterogeneous with particular hot spots arranged randomly.•The mobility of Cd, Pb and Zn is very high.•The ecosystem of the Peru Park is strongly impacted.