Environmental Assessment of the Caveira Abandoned Mine (Southern Portugal): Part 1: Characterization of Metal Contaminated Soil

Abstract

Mine activity in Portugal had a huge impact on the growth of the regions where it took place, like in the Iberian Pyrite Belt. Nowadays, most of these mines are abandoned, as is the case for the Caveira mine. Soil geochemistry indicates that high contents of Cu, Pb, Zn, As, Cd, and Hg occur in the soils collected near the tailings. Multiple Correspondence Analysis identifies two areas with high concentrations of Pb, As, Hg, Sb, Mo, and Tl. However, the results suggest a different geochemistry for each of the areas. The non-site-specific methods (Hazard Index and GLC guidelines) classify all the areas as contaminated. Metal fractionation in the soil phases is different for the several elements studied. The articulation of the metal fractionation results with the GLC guidelines reduces the area of soil contaminated by Pb, but not by As.

Keywords:

• Environmental assessment
• heavy metals
• Caveira mine
• Iberian Pyrite Belt
• soil

Acknowledgements

This study was possible with the financial support provided by IAPMEI–Ministério da Economia. Particular acknowledgments are addressed to INETI for authorizing the use and publishing of the data from the Project “Estudo do Controle Ambiental nas áreas mineiras abandonadas de Lousal e Caveira.”

The authors also wish to express gratitude to the reviewers for their helpful remarks.