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Different global agendas have discussed the role of soils in mitigating and reducing global problems related to climate change, food security, biodiversity and erosion, among others. With this in mind, the aim was to draw up an overview of the main soil agendas in Europe and Brazil, analysing their impact on the establishment of legal frameworks for soil use and conservation. In Brazil, pastures are seen as an important alternative for converting degraded areas into ecosystem services. To this end, a literature review was carried out using databases on the Scopus, Web of Science, Science Direct and Scielo platforms, as well as consulting documents from the European Union Missions in Horizon Europe and Brazilian legislation on the subject. In a pilot river basin, the Potential for Conservation Use (PCU) method was applied, which is used in Brazil to assess the impacts of different uses on the natural capital of soils, serving as a metric to guide public soil conservation policies. It was concluded that, on the European scene, discussions on soils have taken place in an integrated and organised way, with actions to mobilise different players in society. In Brazil, even though there are important legal frameworks, actions are still restricted and disjointed, pointing to the need for progress in soil governance. In both scenarios, there is a need for scientifically validated metrics at regional scales that can contribute to a harmonised database capable of subsidising the development of efficient public policies to advance soil conservation at a global level.

The deposits of mine tailings can be a source of groundwater contamination by metals. In this study, we simulated the concentrations of iron, manganese and aluminum in groundwater potentially affected by drainage from tailings deposits located in Brumadinho (Brazil). The aim was to verify whether the concentrations observed in the region can be attributed to these drainages. The simulation used the FREEWAT graphical interface, which incorporates the MODFLOW model, the hydraulic properties of existing unconfined and confined aquifers, the spatial distribution of the tailings’ deposits, and the dissolved iron concentrations measured in drilled wells. The simulation period was 20 years, starting in 2019 after the collapse of B1 tailings dam of Córrego do Feijão mine of Vale, S.A. The modeling results revealed plumes of metal contamination progressively less dispersed over time, in the unconfined aquifer, and increased metal concentrations in the confined aquifer. The simulated concentrations in both aquifers were generally lower than the legal limits imposed for human consumption, although some areas in the vicinity of the deposits had iron and manganese concentrations higher than those limits, especially in the unconfined aquifer, and these areas widened over time. The most relevant result was the revelation that the contribution of tailings drainage to the iron concentrations observed in the drilled wells might have not exceeded 1%. This is important from a management standpoint, because monitoring of anthropogenic groundwater contamination in these cases (where rock weathering dominates groundwater chemistry) becomes more challenging.

Qualifying and quantifying the value of environmental damages that have affected a particular region following a catastrophic event is not always an easy task, because some damages are perceived in the short-term and others can only manifest themselves after many years. Expressing the environmental damage through mathematical formulas is even more difficult to undertake, because some damages can be easily measured and others can be more complex to scale. When it comes to environmental damages caused by tailings dams bursts, the task of estimating their economic value becomes even more complicated considering the multiplicity of factors involved and the length of time they remain at the affected sites. Despite all these uncertainties, the allocation of a monetary compensation to those responsible for the damage is a public duty, so the development of credible and fair methodologies for the economic valuation of environmental damages is a mandatory challenge. With this in mind, in order to financially measure events that promote environmental degradation, we proposed the EVED methodology – Economic Valuation of Environmental Damages, inspired on the standard VERA – Economic valuation of environmental resources. The novelty of EVED is that it moves the focus from valuating the environment based on the classification of features' “use” or “no-use”, to valuating the environment based on the recovery and repair time scale. The tested site was the Ribeirão Ferro-Carvão watershed located in the municipality of Brumadinho, state of Minas Gerais, Brazil, which has been affected by the collapse of B1 tailings dam of Vale, S.A. mining company, in 2019. The valuation of environmental damages was restricted to the natural vegetation of Atlantic Forest biome impacted by the tailings' mudflow. The results revealed losses of ecosystem services amounting to R$ 163,641,289.5, and costs to repair (clean) the affected areas (valley and banks of Ribeirão Ferro-Carvão) amounting to R$ 571,346,957.9. These results increased previous estimates, but were considered more realistic since this study took into account the value of affected ecosystem services as well as the value of direct costs related to the removing of tailings from the affected sites, combined with the effect of time on these values, something that was not previously the case. It was therefore concluded that the EVED methodology provides a realistic framework for the financial amounts to be imputed to mining companies as monetary compensation related to the collapse of tailings dams. It should be noted that the study has valued the damage related to the impact of B1 dam collapse on the natural vegetation of Ribeirão Ferro-Carvão's channel and banks, meaning that it does not represent a comprehensive analysis of environmental damages caused by the disaster, which would naturally have to include damages related to the degradation of soil, air and water, among other compartments. It should also be said that the EVED methodology comprises a set of financial valuation tools designed to support judicial decisions, and does not address moral damages or life loss.