Environmental context. Platinum concentrations in natural waters such as oceans, rivers and lakes are extremely low, hindering studies of Pt distributions and biogeochemical cycles. An improved electrochemical method was used to reliably determine Pt in estuarine conditions at trace concentrations. Platinum displayed a near-conservative behaviour along the salinity gradient of the estuary, with about 90 % remaining in the dissolved form.

Environmental context. Among chemical elements classified as elements of strategic importance, tellurium is rapidly becoming an emergent contaminant. There is, however, no accurate and sensitive method for measuring tellurium concentrations in environmental and geological samples (e.g., soils, sediments), and thus it is not possible to determine whether an ecosystem is being polluted by human activities. This study provides a reliable answer to this problem.

Environmental context. Natural weathering of rocks may release technology critical elements (TCEs) to the environment, and anthropogenic activities can noticeably increase TCE release rates. We investigated acid mine drainage outflows from an underground sulfide mine in south-west Spain, reporting TCE concentrations orders of magnitude higher than those observed in natural waters. The findings improve our knowledge on mobility of TCEs in different geological settings.

Environmental context. Emerging contaminants such as platinum are continuously released into aquatic environments. Analytical challenges, however, have restricted information on their geochemical cycles. We examine the potential use of platinum as a tracer of anthropogenic inputs in a model industrial/urban site (Genoa Harbor, Italy), and provide a first estimate of dissolved platinum baseline concentrations in the northern Mediterranean coast.

Environmental context. Technology-critical elements, widely used in modern industry, are found in the environment as a result of both anthropogenic usage and natural sources. This review describes current knowledge on the transport of technology-critical elements in sand, soils and aquifer environments. The chemical compositions of the soils and groundwaters influence the transport of technology-critical elements, and natural colloids increase their mobility.

Environmental context. The origin of organic matter at Earth’s continental surface can be either terrestrial or microbial, and its precise composition can influence its reactivity towards metals. We investigated the potential of rare earth elements to fingerprint the origin of various organic matters through their reactivity and composition. The rare earth element patterns can be useful tools to determine the reactivity and also pristine source of natural organic matter.

Environmental context. Natural organic matter exerts a powerful control on chemical conditions in waters and soils, affecting pH and influencing the biological availability, transport and retention of metals. Modelling can help to predict these effects, but for many metals, model parameters are missing. We report parameters for four technology-critical elements in a chemical speciation model, and consider the chemistries of the elements in natural waters.

Environmental context. Rare earth element profiles of foodstuffs reflect both the soil fingerprint and the specific agricultural practice for a certain location. This review describes the advantages and limitations of using rare earth elements as markers for geographical discrimination as a function of food matrix. The technique has great potential for establishing the geographical origin of foodstuffs.

Environmental context. Indium is a metal increasingly used in high-technology industries, creating a demand for efficient recycling technology. We investigated extraction of indium from waste using a subcritical water extraction with organic acids. Compared with conventional methods employing concentrated mineral acids, the new method is less corrosive, more efficient and required shorter extraction times.

Environmental context. Although ruthenium is a technology-critical element used in several new industries, little is known about its environmental impact or possible human health risks. We report a toxicological evaluation of laboratory animals during co-exposure to ruthenium and silver. We identified interactions between the two elements that could lead to unwanted biological effects.

Environmental context. Antimony is found at high concentrations in airborne particulate matter in urban cities. Contaminants that enter humans through the breathing of fine particulate matter are released directly into the blood after overcoming the first barrier of the immune system including macrophages. We investigated the effects of antimony on the inflammatory response in macrophages and its potentially harmful effects.

Environmental context. Antimony is a metalloid occurring at overall low concentrations in the Earth’s crust. Owing to anthropogenic activities, however, antimony can be found at elevated and detrimental levels in some environments. We report eco-toxicological effects of antimony in biological models, results from which can help predict antimony’s ecological and environmental impact.

Environmental context. Rare earth elements (REEs) are strategic metals and emerging contaminants for which plant-based remediation measures are needed. We screened a collection of hardy ferns and identified new accumulator species that preferentially transferred light REEs to their fronds. This study is an important step towards understanding the mechanisms of REE accumulation in plants.

Environmental context. Despite thallium’s high toxicity, water solubility and bioaccumulation tendency, its ecotoxicological relevance is largely unknown. We investigated thallium concentrations in fish, amphipods and parasitic worms from a karst freshwater ecosystem, and estimated total and cytosolic thallium concentrations in intestine of fish from the karst and lowland rivers impacted by wastewater inflow. The study provides the first data on dietary thallium accumulation in the intestine of freshwater fishes.