Mercury pollution caused by artisanal gold mining the Ocoña river Valley, Peru

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The use of mercury for gold recovering in the artisanal gold mining from the Mapiri river basin, Apolobamba, Bolivia

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Environmental pollution produced by gold artisanal mining in the Mapiri river basin, Apolobamba, Bolivia

Mining activity is very important in Bolivia since colonial times. Today it has been reactivated, especially gold mining, due to rise in metal prices. Artisanal and small-scale mining activities are abundant in the protected area of Apolobamba, near the border with Peru. Here mercury is used to recovery gold by obtaining an Hg-Au amalgam. This manipulation with mercury causes an important environmental impact in the area. The present work is a preliminary study of the contamination of the Mapiri river basin in the Apolobamba area. In the head of this basin, located at more than 4000 m above sea level, gold is mined from hydrothermal gold deposits of Paleozoic age. We have sampled several mining sites from this area, in particular the ones known as Viscachani, Flor de Mayo and Chojlaya, located in the proximity of the head area of the Mapiri river basin. These mining sites were in activity during the present sampling campaign. Different metals were measured by means of XRF (Se, As, Cu, Zn, Cd, Pb, Hg) in tailing samples from the different gold mining sites. In addition mercury concentrations were measured in water and in vegetation close to the processing areas by means of atomic absorption spectrometry with Zeeman effect (LUMEX RA-915 Equipment). Tailings are mainly constituted by quartz with minor contents of clay minerals and sulphides. The most abundant sulphides are galena and arsenopyrite. Chalcopyrite, sphalerite, pyrite and sulphosalts also occur in minor amounts, as well as minor secondary minerals. Gold content, after recovery with mercury, is high, between 4.56 ppm and 10.35 ppm. The Hg content of the tailings ranges from 149 to 1027 ppm. Lixiviable mercury from these samples ranges between 30.10 and 859.94 ng l-1. Water released from the tailings contains between 0.1 and 5.7 ppb of Hg. Studied vegetation typical of the area has high Hg contents, between 162 and 219 ppm. In addition there is a high arsenic content in all the studied tailings, except in those from the Viscachani mining site, where concentrations of this element ranges from 456 ppm to 18540 ppm. The Pb content usually ranges from 337 to 939 ppm. The Chojlaya mining site tailing has exceptionally high values of heavy metals: Pb content is between 2.26 and 3.27 wt.%, Cd ranges from 160 to 228 ppm, Zn from 194 to 794 ppm, Cu from 847 to 1052 ppm and Se from 105 to 187 ppm. These contents also contribute to an environmental pollution. In conclusion the gold mining activities in the Mapiri river basin produce and intense environmental pollution, mainly related to mercury and arsenic contents in the proximity of these mining activities. After processing, tailings still contain important amounts of gold suggesting that the amalgamation method is not effective to gold recovering.Peer ReviewedPostprint (published version

Landscape, tourism and sustainability. Aranjuez case study

El paisaje ha adquirido un nuevo valor desde la Unión Europea, con la aprobación del Convenio Europeo del Paisaje (2000), otorgando al paisaje el carácter jurídico del que carecía y estableciendo su valor para la identidad de los pueblos y las características de un territorio, mediante la asunción de políticas activas variadas, no solo la conservación, sino la renovación, la creación o la gestión. Con estos antecedentes se presenta el Plan de Gestión del Paisaje Cultural de Aranjuez (director Miguel Angel Anibarro, sección ambiental Fariña-Higueras), que constituye el primer paisaje cultural declarado por la UNESCO en España. El objetivo principal del Plan de Gestión es proyectar redes de ocio municipales, que utilicen el conocimiento de los valores naturales, ambientales, culturales y antrópicos del territorio, estructurados en una serie de recorridos temáticos que permitan el entendimiento integral de los mismos por parte de la población residente y visitante y generen riqueza económica a la comunidad local. Se propuso la adecuada gestión de la capacidad de carga turística del territorio, la diversificación de las actividades de ocio y la generación de riqueza y empleos detectando aquellos valores de interés e incluirlos como parte de la oferta de turismo “natural”, convenientemente estructurados en pequeños equipamientos e instalaciones. Como conclusión, la declaración de un Paisaje Cultural debe ser una oportunidad para establecer unas estrategias de acción combinada entre la calidad intrínseca de un paisaje valioso y las acciones, usos o funciones que se han incorporado al mismo por la acción humana a lo largo del tiempo. Abstract: Landscape has acquired a new value from the European Union, with the approval of the European Landscape Convention (2000), granting to the landscape a legal character and establishing its value for the identity of the citizens and their territorial characteristics, Through the assumption of varied active policies, not only conservation, but renewal, creation or management. With this background is presented the Aranjuez Cultural Landscape Management Plan (director Miguel Angel Anibarro, environmental section Fariña-Higueras), which is the first cultural landscape declared by UNESCO in Spain. The main objective of the Management Plan is to project municipal leisure networks, using knowledge of the natural, environmental, cultural and anthropic values of the territory, structured in a series of thematic tours that will allow the integral understanding by the residents and visitors and will generate economic wealth to the local community. It was proposed the adequate management of the tourist capacity of the territory, the diversification of leisure activities and the generation of wealth and jobs detecting those values of interest and included them as part of the offer of "natural" tourism, conveniently structured in small facilities. In conclusion, the declaration of a Cultural Landscape should be an opportunity to establish combined strategies actions between the intrinsic quality of the place and the actions, uses or functions that will be incorporated by human action over time