Rare earth elements (REEs) are increasingly recognized as significant environmental pollutants due to their environmental persistence, bioaccumulation, and chronic toxicity. This study assessed REEs pollution in soil, water, and vegetables in an ion-adsorption rare earth mining area in Ganzhou, and evaluated the associated health risks to the local population. Results indicated that the REEs content in soil ranged from 168.58 to 1915.68 mg/kg, with an average of 546.71 mg/kg, substantially surpassing the background level for Jiangxi Province (243.4 mg/kg) and the national average (197.3 mg/kg). Vegetables displayed an average REEs content of 23.17 mg/kg in fresh weight, far exceeding the hygiene standard of 0.7 mg/kg. Water samples contained REEs at a concentration of 4.09 mu g/L. The estimated daily intake (EDI) of REEs from vegetables exceeded the threshold for subclinical damage, posing potential health risks, particularly for children and adolescents. Further analysis of the adjusted average daily intake (ADI) and non-carcinogenic risk suggested that while most vegetable consumption remains within safe threshold, the intake of REEs from high-risk vegetables such as pakchoi should be limited. Overall, carcinogenic risks associated with lifetime cancer risk (LCR) model for REEs exposure through vegetables and water were found to be low in this area.

Considering the increase in demand for rare earth elements (REEs) and their accumulation in soil ecosystems, it is crucial to understand their toxicity. However, the impact of lanthanum, yttrium and cerium oxides (La2O3, Y2O3 and CeO2, respectively) on soil organisms remains insufficiently studied. This study aims to unravel the effects of La2O3, Y2O3 and CeO2 nanoparticles (NPs) and their corresponding bulk forms (0, 156, 313, 625, 1250 and 2500 mg/kg) on the terrestrial species Enchytraeus crypticus. The effects on survival, reproduction (21 days (d)), avoidance behavior (2 d) and DNA integrity (2 and 7 d) of E. crypticus were evaluated. No significant effects on survival were observed. For La2O3, the bulk form affected more endpoints than the NPs, inducing avoidance behavior (1250 mg/kg) and DNA damage (1250 mg/kg- 2 d; 2500 mg/kg- 7 d). The Y2O3 NPs demonstrated higher toxicity than the bulk form: decreased reproduction (>= 1250 mg/kg); induced avoidance behavior (>= 625 mg/kg) and DNA damage (>= 156 mg/kg- 2 d; 2500 mg/kg- 7 d). For CeO2, both forms exhibited similar toxicity, decreasing reproduction (625 mg/kg for bulk and 2500 mg/kg for NPs) and inducing DNA damage at all tested concentrations for both forms. REEs oxides toxicity was influenced by the REEs type and concentration, exposure time and material form, suggesting different modes of action. This study highlights the distinct responses of E. crypticus after exposure to REEs oxides and shows that REEs exposure may differently affect soil organisms, emphasizing the importance of risk assessment.

This study investigated using rare earth elements as tracers to study wildfire impacts. The study area was Antalya, located in the Mediterranean region of T & uuml;rkiye. This region is known for the frequent occurrence of wildfires, which cause significant damage to the flora and fauna of the area. A series of wildfires occurred in the region in 2016. Soil samples were collected from the affected areas to understand these wildfires' impact better. Instrumental neutron activation analysis was used to analyze the samples. The study found that the north-facing aspect had higher concentrations of rare earth elements. This could be because north-facing aspects are cooler and more humid, with less erosion, leading to better ecological restoration and less transportation of rare earth elements.

Purpose of ReviewThis review examines recent publications on rare earth elements (REE) in soils, critically evaluating their role as emerging soil contaminants. We emphasized new findings and main gaps using a previous review paper published in 2016 by our research group as a reference point. Three major subjects were prioritized: (1) sources, background levels, and behavior of REE in soils; (2) plant development and metabolism as affected by REE exposure; and (3) environmental and human health risk assessments of REE in the soil environment.Recent FindingsPublications addressing the occurrence and fate of REE in the soil environment have more than tripled in the last decade. Coincidentally, global REE exploration has more than doubled in the past 7 years. Because of their unique features, the global demand for REE is expected to increase by at least 50% in the next 10 years. As soils are the main sink of contaminants, we must continue to investigate the consequences of the unceasing addition of these elements in soil ecosystems.SummaryWe highlighted the main sources of REE, their background levels in selected global soils, and their physicochemical behavior. The relationship between REE and plants revealed potential benefits such as environmental stress tolerance. Finally, ecological and human health risk assessment data for REE in soils were carefully discussed in terms of their potential adverse effects on biota. We conclude with a survey in which prominent authors working with REE answered questions about challenges and opportunities for innovative research on REE in soil-plant-animal/human systems.

In modern industries, rare earth elements (REEs) are considered as essential metals and invaluable natural resources. Ion -adsorption deposits (IADs) are repositories of REE in the weathering crust soils, in which REEs are adsorbed on clay minerals. In the last few decades, the mining of REEs from IADs has caused substantial environmental damage owing to the overuse of leaching agents for the desorption and transport of REEs in weathering crust soils. These environmental issues have sparked extensive research interest in modeling REE transport dynamics in weathering crust soils. Nevertheless, because current models treat REE adsorption and transport independently, they do not accurately describe REE transport dynamics. Therefore, in this study, a unified workflow that synergizes adsorption and transport dynamics is proposed to predict REE transport. The adsorption of REEs on IADs was found to follow the Freundlich isotherm with the coefficient of determination exceeding 0.9826. The adsorption capacities of La 3+ , Sm 3+ , Er 3+ , and Y 3+ reach 1.3127, 1.4423, 1.5793, and 1.1061 mg g -1 at 300 ppm, respectively. For the breakthrough curve, an advection - dispersion - adsorption - eq- uation (ADAE) model was developed and utilized to accurately and reliably predict REE transport dynamics in soil columns. It was found the saturation time of REEs in soils is 39.22, 44.15, 50.64, and 32.17 h, respectively at 2 mL min -1 and decreased with the increase of flow velocity. The upper and lower limits of REE transport are ADAE-Freundlich and ADAE-Toth. More importantly, the model was applied to simulate REEs transport in fieldscale weathering crusts over 100 years and predict REE accumulation in the highly weathered layered, which is found in natural weathering crusts. The qualitative prediction of REE transport dynamics in weathering crusts may help fundamentally lower the usage of leaching agents and mitigate concomitant the environmental impacts of mining.

In-situ leaching (ISL) has gained prominence as a non-destructive method for rare earth element (REE) extraction, particularly in regions like China. However, concerns over the environmental impact and soil stability due to ISL activities have surfaced following a landslide incident. This article distills the essence of a comprehensive research endeavor that delves into the effects of ammonium sulfate ISL leaching, employing concentrations of 0.05M, 0.1M, and 0.5M, on soil mechanical properties. The study encompasses physicochemical, physical, and mechanical tests, unveiling substantial alterations in shear strength, cohesion, angle of internal friction, zeta potential, liquid limit, plastic limit, and plasticity index following leaching. XRF and XRD analyses reveal the presence of REEs and distinctive mineral phases in the soil samples. Overall, ISL induces a weakening of the soil, raising concerns about potential slope failures and emphasizing the need for a deeper understanding of ISL's impact on soil properties in the context of REE mining.