The environmental impact of mineral deposits: a case study at Bottino, Apuane Alps, Tuscany

In the abandoned Bottino Pb-Zn-(Ag) mining district (Apuane Alps, Tuscany) the pedological, mineralogical and chemical features of four soil profiles collected at variable distance from mining waste dumps were investigated. The environmental impact of mining activity onto soils, plants and surficial waters in the mine area was evaluated by means of different analytical techniques. Sequential extraction analysis of soil samples pointed out that heavy metals are still bound to primary phases like sulphides (galena, sphalerite, etc.) and/or carbonates (siderite): this datum agrees well with observed textural and mineralogical features of mine dumps, showing minor alteration of metal-bearing phases, and the overall low heavy metal concentrations of stream waters. Some plants, however, grown onto, or in close proximity to, mine wastes, show heavy metal contents that exceed the phytotoxic limits