Panasqueira mine environmental quality evaluation. Soil-water-arbutus unedo. Social and environmental case study

Mestrado em Engenharia do Ambiente - Tecnologias Ambientais - Instituto Superior de AgronomiaPanasqueira mine is one of the last three mines actually in labour. Tungsten, copper and tin are explored for over a century. The visual and chemical impact of the exploration is due to active and old huge tailings and due to draining from mine, water plant treatment and seepage water. The objective of this study was to evaluate the biogeochemical impact of the mine activity in soil, water and strawberry tree (Arbutus unedo L.). Soil is contaminated with copper, zinc, arsenic, tungsten and lead and the consequent impact was observed in microbial soil enzymes. Selective chemical extraction of trace elements allows to assess elements in soils and their absorption in plant roots and translocation to branches, leaves and fruits. Arbutus unedo is a manganese and zinc tolerant, and is not accumulator of trace elements. However, this species presented high concentration of cadmium in the aerial parts. The analysis of sediments and water from Ribeira of Bodelhão indicate that trace elements are dispersed from the primary contaminated area, to Zêzere River, where the dilution drastically eliminates the contamination effects. The strawberry tree fruits can be used to produce alcohol as they are not contaminated. A. unedo can be used in phytostabilisation programs of contaminated soils and tailings