Panasqueira Mine (Portugal) Amelo R, Acandeias C, A,Bávila P F, Asalgueiro a R, A,Bferreira A, Aferreira Da Silva E
46 Heavy metal pollution in Mine-Soil-Plant System in S.Francisco de Assis - Panasqueira mine (Portugal) aMelo R, aCandeias C, a,bÁvila P F, aSalgueiro A R, a,bFerreira A, aFerreira da Silva E The active Panasqueira mine is a Sn-W mineraliza- open impoundments are the main source of pollu- tion hosted by metasediments with quartz veins rich tion in the surrounding area once the oxidation of in ferberite. The economic exploitation has been sulphides can result in the mobilization and migra- focused on wolframite, cassiterite and chalcopyrite. tion of trace metals from the mining wastes into the The mineralization also comprises several sulphides, environment, releasing contaminants into the eco- carbonates and silver sulphosalts. The mining and system. beneficiation processes produces arsenic-rich mine In order to investigate the environmental contamina- wastes laid up in two huge tailings and open im- tion impact on agricultural and residential soils of the poundments, one deactivated and the other (Barroca nearest village, S. Francisco de Assis, due to the min- Grande tailing) still active. the rejected materials from ing activities, a soil geochemical survey was under- the ore processing, containing high concentrations taken. Seventeen rhizosphere soil samples were col- of metals, stored in the open-air impoundments lected and their median reveal higher contents (mg are responsible for the continuous generation of kg-1) of As=224, Cd=1.3, Cu=164, Pb=59, Zn=323 acid drainage. Average contents (mg kg-1) in Bar- then the national median concentrations proposed roca Grande impoundment of As=44252, Cd=491, by Ferreira (2004) As=11, Cd=0.1, Cu=16, Pb=21, Cu=4029 and Zn=3738 and in Rio impoundment Zn=54.5.
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