There is a wicked paradox between the fact that metal production is essential to the global sustainable energy transition and the fact that metal production often leads to a degraded quality of life for people living near the production sites due to contaminant emissions. Involving citizens in implementing mitigation measures around metal processing (MP) sites is a key objective of the United Nations. However, establishing community engagement around MP sites has posed challenges so far because the discrepancy between the global interests of metal operators and the local concerns of residents hinders dialogues and concertation. We hypothesize that combining the perspectives of citizens and metal operators will enable us to collectively design solutions for a better quality of life near MP sites and therefore, empower citizens to implement mitigation measures. To explore this hypothesis, we will focus on 2 major MP operations: primary mining of lithium in Ghana and recycling of lead in Senegal. COMBINE will co-build knowledge and solutions to transform the quality of life near metal processing sites, by 1. evaluating the impact of MP activities on their living environment from the citizen perspective, 2. describing the metals processing and their emissions from the MP sites perspective, 3. implementing solutions to both promote sustainable policies and empower citizens around/for MP sites. We will rely on the combination of participative biomonitoring methods implementing passive vegetal sensors and MP site description that we have developed. By linking, for the first time, our 3 disciplines -geosciences, process engineering, anthropology- with participatory sciences, our consortium makes it possible to study simultaneously the processes inside MP sites and contamination outside thanks to a source-to-sink approach, bringing a global understanding of impacts of metal production and proposing associated win-win solutions that will pave the way to design new policies.

Complex life (e.g. animals) demands oxygen, and its emergence requires the transition from hostile, oxygen-free (anoxic) environments, to the well-oxygenated conditions we experience today. While our tools permit us to reconstruct the extent of extreme (anoxic or O2-rich) conditions, we currently lack the proxies to quantify intermediate (dysoxic) conditions, which may have characterized the environments where complex life emerged and evolved. Recently, we showed that modern-like oxygen minimum zones were established during the rise of animal life in late Precambrian. This project will focus on the calibration and the application of U isotopes to identify dysoxic conditions in these systems, in order to address how oxygen availability links to the evolution of early animals. The project comes at a key point in the current debate on animal evolution and ocean oxygenation, and it will constitute a fundamental step forward in reconstructing palaeo-environments throughout Earth’s history.

In order to comply with the national low carbon strategy (SNBC) and the energy decarbonization objectives by 2050, it is necessary to develop decarbonized energy transformations and productions, i.e. not based on fossil carbon but on renewable carbon stocks, so either biomass or gaseous carbon dioxide. The transformation of CO2, whether it is of industrial origin (smoke) or biogenic (from biogas, for example), is proving to be an important asset for the future. In this project, we propose to work on the valorization of CO2 into calcium/magnesium carbonate in the form of rocks. This transformation will be carried out by microorganisms and in particular microbial consortia. The objective is therefore to select, from environmental microbial consortia, populations of APSB (Anaerobic Phototrophic Sulfur Bacteria) and to characterize their activity in terms of yields and microbial kinetics, production of exopolymers, and this according to of different growth conditions. In a second step, the addition of calcium and magnesium will make it possible to study the potential for inducing the precipitation of carbonates, for a subsequent coupling with a sulphate-reducing activity. Finally, the study proposes to focus on the microbial pathways involved in the sulfur cycle. Indeed, in the environment (ocean, lake sediments), the sulfur cycle participates via different biological and physico-chemical reactions in the bioprecipitation of carbonate salt. In particular, sulphate-reduction leads to the alkalinization of media, and the production of bicarbonate ions from MO, a phenomenon favorable to this type of reaction. The production of reduced sulfur in the form of H2S during this reaction is a potential substrate for phototrophic sulfur bacteria (APSB). This type of coupling, between chemotrophic and phototrophic pathways, takes place in the environment within microbial mats (ocean and lake sediments). By associating two complementary teams in this collaboration, the project will make it possible to understand and qualify the mechanisms involved and the role of APSBs, and to investigate the potential of such a coupling for the capture of CO2 by the culture in a bioreactor of APSB for optimization of carbonate precipitation.

Air quality in school is a crucial sanitary issue that Coop'AIR wants to address with the co-construction of local solutions by the actors of the environment themselves, in collaboration with a multidisciplinary team made up of scientists specialized in fine particles measurements, members of environmental education associations and researchers in information and communication sciences. The approach is based on various means of subject’s appropriation (artistic creation, scientific approach, use of technological or biosourced sensors, dialogue...). It also includes international experience sharing through a dedicated Web platform because as WHO stated "the air quality knows no borders". Empowering pupils to become actors in the evaluation of their environment and in particular of the air they breathe in their classrooms is one of the goals of Coop’AiR. The project aims at investing the school microcosm through transdisciplinarity and participative sciences in order to create a methodology of participative research adaptable to several school contexts on three continents (by taking into account the spatial scale, population density, the socio-cultural aspect...). Coop'AiR arise from the reflection of a solid consortium associating Research and civil society, already sharing several participative research programs on air quality and willing to design this action towards the school environment. Coop'AiR is thought as an experiment of research - implication – action with a vocation to expand after the end of the project to other subjects related to school environment (vegetation, diversity, noise, equality etc ....)

Almost all natural H2 seepages identified over the last 30 years, both on the continents and on the seafloors, are from ultramafic geological environments where olivine and pyroxene serpentinization is the source of H2. There is, however, another very different geological context where spectacular enrichments of H2 are documented, both in fluid inclusions and as free gas migration through rock fractures, mine galleries, and soils. These are peralkaline/agpaitic igneous intrusions, among which those of the Kola Peninsula in Russia (Khibiny and Lovozero) are the two world’s largest known occurrences. These two plutons host giant deposits of strategic metals (REE, Nb, Ta, Zr, Ti), and the emission of explosive gases (H2 and HCs) is a major hazard for miners. To this day, the sources and fluxes of H2 and associated gases are still unknown. Similarly, the role that these volatiles may have played in the genesis of the giant ore deposits associated with these plutons remains undocumented. This research project aims at investigating the behavior of H2, CH4 and other gases in these igneous intrusions, from their deep sources to the atmosphere into which they finally escape. The outcomes of this study will contribute to unravel many aspects that still remain controversial or altogether obscure on the origin and behavior of these gases, their relationship with the rare metal mineralizations, as well as their environmental impacts. Our ambition, through this case study, is to lay the foundation of H2 exploration, and to provide a global overview of H2 geochemical cycle from sources to seeps. To achieve this goal, we will combine: 1) Analytical developments: The aim is to i) set up a portable mass spectrometer to perform on-site measurements of the stable isotopic (C, O, H) composition of CH4, CO2, and to obtain He partial pressure; ii) develop new type of passive gas sensors based on gas physisorption, and iii) deploy a Cavity Ring-Down CH4 spectrometer on a drone. 2) Field studies of H2 and associated gas migration: This aspect will deal with: i) tracing the source and migration pathways of H2, CH4 and associated gases (He, Rn, CO2, N2, HCs); ii) measuring spatial and temporal variations of surface gas release, which will reveal the geological controls on gas migration. 3) Investigations on the consequences for ore genesis, environmental perturbations and energy resources: This part will focus on i) assessing the role of H2 and associated HCs of putative abiotic origin on ore-forming processes; ii) identifying biogeochemical anomalies in soils, and iii) setting up an exploration guide for natural H2 within an industrial perspective. Our consortium is composed of world-class specialists of these geological objects and H2 migration in the lithosphere. All needed skills and know-how are reunited within an interdisciplinary team to complete this project in a timely and efficient manner. In Russia, Drs. J.A. Mikhailova (PI Russia, mineralogy, petrology expert) and V.A. Nivin (gas geochemistry expert), together with junior researchers from the Kola Scientific Center, will lead the field investigations. In France, Prs. L. Truche (PI France, IUF Junior member) and F-V. Donzé (geomechanics) at ISTerre laboratory (Univ. Grenoble) are specialists in the abiotic reactivity of H2 and gas drainage in fault systems. They know Russia very well and have already established a collaboration with the KSC-RAS thanks to the CNRS-INSU project HyNa. Dr. S. Salvi (CNRS researcher), GET laboratory (Univ. Toulouse, France) is a world specialist of peralkaline granites and their associated ore deposits. In addition, biogeochemists will provide important savoir-faire for studying the impact of gas migration on surface ecosystems. Finally, 2 postdoc researchers, and 2 Master students will work in joint supervision between our laboratories, which will contribute to strengthen scientific relationships between the partners.