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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Biogeochemical characterization of soils affected by more than 100 years of lead mining activity.

International audienceMining has an adverse effect on soil quality as it is a source of heavy metal environmental pollution with direct consequences on its ecosystem services, especially those related to microbial activity. The magnitude and diversity of the impact produced by pollution is linked to the complexity and diversity of mining processes that share the same mining area. The soil will be modified, not only in the physicochemical characteristics but also physical alterations of varied typology will occur. All these changes and alterations related to mining activity are accompanied by changes in the composition, diversity and activity of soil microorganisms..A study was carried out on a mine site showing variable degrees of contaminations with metals, to estimate the impact of mining works on the geochemistry of soils, and the activity and diversity of soil microorganisms. The aim is to characterize the level of disturbance on the “soil health” due to the presence of different metals, related physicochemical factors, and typology of the wastes affecting the soil. Besides, the process of bacterial colonization of the wastes has been also subject of interest to our work.The selected study area was originally a lead-silver mine. Later, a mineral treatment plant was established in the area in order to recover Zn from the primary gangue dumps. In addition spills of olive mill residues were later deposited in the area. Four composite samples from the five distinct sites differing in their characteristics were selected: tailings, dumps, olive mill residues, contaminated soil and reference soil. A range of various analyses was done on these samples including pH, electrical conductivity, organic matter, multi-elemental contents, enzymatic activity and bacterial biodiversity (16S rRNA amplicon sequencing).Selected sampling sites have contrasted physicochemical characteristics: acidic pH was observed in dumps (3.8 in average) and neutral in tailings and soils (~6); highest conductivity was recorded in dumps (2282 microS cm-1 in average) and lowest in soils (62 microS cm-1 in average); the highest organic matter value was measured in soils amended with olive mill residues (60% in average). Heavy metals were detected in higher concentrations in dumps and olive mill residues than in tailings or soils. It is noteworthy in dump samples the maximum concentrations of metals reach 6.8% with significant amounts of Zn, Cu, Sb, Hg, Ni, Co and Mn. Highest enzymatic activities were measured in contaminated and non-contaminated soils, while lowest values were obtained in dumps and tailings soils, in accordance with the concentration of metal measured in the matrix. Next generation sequencing analysis of 16S rRNA amplicon lead to the discrimination on the different sites sampled according to bacterial composition and diversity. Most abundant bacterial phyla were Proteobacteria, Actinobacteria, Chloroflexi, Acidobacteria, Gemmatimonadetes, Bacteriodetes, TM7, Firmicutes, Cyanobacteria and Verrucomicrobia.As a conclusion, we have found evidences of the intense affection of the metal pollution to the microbiological biodiversity, particularly that related with the presence of high Pb concentrations

The economic impact of climate change on urban drainage master planning in Barcelona

In the context of global change, urban drainage infrastructures must be planned considering future challenges such as new climate change and urban growth scenarios. Large cities require master plans to properly rank and schedule infrastructure development. The flood mitigation measures proposed in previous plans must be revised and updated to address future urban challenges with special regard to climate scenarios. Regarding risk assessment, there is no linear relationship between an increase in rainfall and an increase in risk value. For risk management, the relationship between an increase in rainfall increase and the budget for mitigation measures is even more complex. To investigate this relationship and the economic impact of the aforementioned update, a new plan should be elaborated. Urban drainage master plans have been developed in Barcelona city for the last 50 years. In terms of rainfall, the impact of climate change has been established to be an increase of 7–26% at peak intensity, depending on rainfall duration. The Integral Drainage Master Plan of Barcelona (PDISBA) addresses these new challenges. The modification of rainfall scenario planning and the typology of mitigation measures result in an important rise in investment budget, infrastructure life cycle, and operation and maintenance budgets for said infrastructure. The total cost of the planned measures outlined in the PDISBA has risen to €1.442 million, nearly double that of the previous plan developed in 2006.This research was funded by the Barcelona City Council, contract number E18-0185.Peer ReviewedPostprint (published version

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

Peer Reviewe

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

Peer Reviewe

Low-cost geochemical surveys for environmental studies in developing countries: testing a field portable xrf instrument under quasi-realistic conditions.

Environmental monitoring, as a prerequisite for environmental risk assessment, is crucial in developing nations from Africa, Latin America, South East Asia, or Melanesia, where conspicuously most of the Worlds mining activity concentrates. One of the most important environmental problems relates to the disposal of mine concentrates to river systems (e.g., Irian Jaya or Papua New Guinea). However, environmental monitoring is severely restricted in developing countries due to the chronic lack of funds. This paper explores the potential for a wider use of Field Portable X-Ray Fluorescence Spectroscopy instruments (FPXRFs) in fast, real-time, cost-effective environmental surveys for heavy metal dispersal in developing countries, where access to fully equipped geochemical labs is not usually a viable option. We simulated a scenario resembling conditions to be found in a remote region affected by mining-derived metal pollution where no proper laboratory facilities existed. We used an OXFORD X-MET 3000TX XRF analyzer under quasi-realistic conditions, relying solely on the instrument to allow geochemical characterization of a highly polluted Pb-Zn old mining district in the Alcudian Valley of central Spain. Our results for Pb, Zn, Cu, As, and Cd from 12 mine sites showed an excellent performance of the instrument, both under real-time and laboratory conditions. Furthermore, the instrument proved to be fit to endure a variety of field operational conditions and was able to deal with different types of samples, including tailings, soils, and stream sediments. Thus, taking into account the affordability of FPXRFs in relation to bench-top laboratory metal analyzers and their operational simplicity, we suggest that these portable instruments should become ?the equipment of choice? for environmental monitoring in developing countries. In this respect, FPXRFs satisfy the system-independence criterion for sustainable development, i.e., the instrument can stand alone and do its job with few or no other supporting facilities or devices. We go further on these matters providing some hints on how FPXRFs could become widely available via international cooperation, and the technical and social benefits that such equipments could bring to foreign aid recipient countries

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

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Time and space variations in mercury and other trace element contents in olive tree leaves from the Almadén hg-mining district

Olive trees (Olea europaea, L.) are a very important agricultural resource for Spain in general and for the Castilla-La Mancha region in particular. These trees provide significant amounts of olive oil and olives for direct consumption. In this paper we discuss analytical constraints regarding the uptake of metallic trace elements from soils and other sources for olive-trees growing in the Almadén mercury mining district, the worlds largest producer of this element, which is currently inactive. The study was based on the analysis of these metals in soils and sets of olive trees of different ages from seven sites located at different distances from the main mercury sources. The results show good correlations between soil and leaf contents for major elements from the soils (Fe, Al, Mg and Ca), but very little or no relationship between metallic trace elements in soils and leaves. However, bioavailable mercury in the soil does correlate well with leaf contents, indicating a significant uptake of this fraction. Furthermore, detailed analysis of the temporal evolution of mercury contents in leaves compared with the temporal evolution of local atmospheric mercury contents, which decreased dramatically in recent years due to the reclamation of the main dump of the mine, indicates some influence of this parameter on the incorporation of mercury in the leaves and suggests a possible mechanism of atmospheric uptake of the element. Mercury contents in local olive oil and olives are slightly higher for samples taken from areas with also higher mercury concentrations in soils, but levels are well below maximum recommended levels for human food