Earth and Environmental Sciences

Schwertmannite and jarosite are naturally occurring iron (Fe) oxyhydroxysulfates with strong sorption capacities for hexavalent uranium [U(VI)] in various acidic sulfate-rich environments. These metastable minerals commonly undergo recrystallization, particularly in the presence of dissolved Fe2+ [Fe(II)aq], which may influence the fate of associated U(VI). Here, we quantified molecular-level changes in U repartitioning and speciation when U(VI)-sorbed schwertmannite and jarosite reacted with Fe(II)aq under near-neutral and anaerobic conditions over 2 weeks. The results show that Fe(II)aq additions promoted rapid mineral transformation to goethite via a dissolution–reprecipitation pathway, proceeding (near-completely) for schwertmannite but slowly and incompletely for jarosite. Importantly, even at early transformation stages when goethite likely only started forming on the surface of the transforming minerals, the recrystallization process led to near-complete retention of U, predominantly as U(VI), within the structure of the neo-formed goethite. Subsequent U reduction to U(V) increased with time but remained incomplete, even after extensive mineral transformation in the presence of 1–50 mM Fe(II)aq for 2 weeks. The results demonstrate that Fe(II)-promoted recrystallization of Fe-oxyhydroxysulfates can rapidly and persistently lock both U(VI) and U(V) into chemically stable goethite, with important implications for predicting U behavior and designing remediation strategies in various acidic and U-contaminated environments.

The Biotic Ligand Model (BLM) integrates geochemistry, physiology, and toxicology to predict the site-specific toxicity of metals relative to water chemistry. We provide a brief history of BLM development, noting that (i) modern versions are done by data-fitting, not by experimentation; (ii) no BLM has yet been developed to predict the toxicity of the most studied metal (Cu) to the most studied fish (zebrafish); and (iii) no BLM has been based on a tropical species. We have returned to experimental basics: 96-h LC50 and 3-h gill binding assays (with radiolabeled 64Cu) in soft water, where individual components were manipulated separately. These yielded Log Ktox values for Cu toxicity, Log Kgill values for gill Cu binding, and LA50 (3-h gill accumulation predictive of 96-h LC50). Key novel findings in zebrafish included (i) a different mechanism of Cu toxicity; (ii) high LA50; (iii) high protection against both gill binding and Cu toxicity by dissolved organic carbon (DOC) and strong cations (potency order Mg2+ > Ca2+ > Na+ > K+); (iv) the BLM constructed using Log Ktox values predicted acute Cu toxicity to adult zebrafish better than one based on Log Kgill values, but the performance of both was superior to generic BLMs for other fish which are in widespread use.

Glaciers are rapidly retreating worldwide due to anthropogenic climate change, with severe implications not only for ecosystems and water security but also for cultural memory, emotional wellbeing, and environmental justice. In the Andes, glaciers are more than reservoirs of ice—they are living beings within Indigenous cosmologies, ancestral knowledge systems, and everyday life. This essay explores the cultural, emotional, and symbolic dimensions of glacial loss, focusing on Andean communities who view glaciers as sacred entities. The sacred dimension of glaciers in many Andean communities also involves legal implications to claim just presents and futures especially for young generations. Building on interdisciplinary perspectives and Rights of Nature frameworks, it argues that glaciers should be recognized not only for their ecological functions but also as more-than-human beings with rights to exist, regenerate, and be protected. The essay critically examines historical and structural responsibilities for glacial retreat—from colonial legacies to the inaction of both Global North and South governments, as well as extractive industries—while advocating for accountability mechanisms such as the proposed international crime of ecocide. At the same time, it highlights local and youth-led initiatives, such as URKUWAMBRA in Ecuador, that foster intergenerational and intercultural knowledge transmission, helping to reimagine responsibility and climate action. Ultimately, the essay calls for an ethical and political shift: to honor glaciers while they are still alive, and to reshape human relations with nature through humility, reciprocity, and caring practices.

Citrate-based plasticizers such as acetyl tributyl citrate (ATBC) and acetyl triethyl citrate (ATEC) are alternatives to phthalates, yet human exposure data remain scarce. ATBC and ATEC are metabolized to acetyl dibutyl citrate (ADBC) and acetyl diethyl citrate (ADEC), which represent relatively specific biomarkers of their respective parent compounds, whereas dibutyl citrate (DBC) and diethyl citrate (DEC) may reflect combined exposure to multiple acetylated and nonacetylated citrate plasticizers and therefore have lower specificity. This study analyzed household dust (n = 47) and urine (n = 363) from 121 participants across three seasons to characterize population-level exposure. In dust, four parent plasticizers, including ATBC, ATEC, tributyl citrate (TBC), and triethyl citrate (TEC) were quantified, with ATBC detected in 37% of samples and concentrations reaching 93.98 μg/g (95th percentile). Four urinary metabolites, ADBC, DBC, ADEC, and DEC, were quantified. In urine, DBC and DEC were detected in over 70% of samples. Mixed-effects modeling showed a significant association between urinary ADBC and DBC, consistent with a shared metabolic pathway. The median estimated daily intake of ATBC from dust ingestion and dermal contact was 0.50 ng/kg bw/day, several thousand times lower than the European Food Safety Authority tolerable daily intake, indicating negligible risk. These findings provide integrated environmental and biomonitoring evidence of human exposure to citrate plasticizers and highlight the need for continued toxicological evaluation.

Abstract Urban riparian zone is the interactive area between human activities and natural processes. Erosion resistance ability of river bank slope considerably affects the prevention of urban flood disaster and aquatic ecosystem. However, due to complex water environment and urban activities, the spatial heterogeneity of riparian soil stability remains elusive. In this study, the spatial variation patterns of soil structure stability in urban riparian zone of River Tour Company in Wuhan, China was investigated from perspective of soil aggregates. First, three representative sites (Wutaizha, WTZ; Huoshui Park, HSP; Sanchakou, SCK) reflecting different urban activities were selected for sampling. Soil physicochemical properties at different spatial locations (sampling site, slope position, and soil depth) were measured and analyzed. Then, soil aggregate stability indices including mean weight diameter (MWD), geometric mean diameter (GMD), and erodibility factor (K) were calculated. At last, the spatial variation pattern of soil aggregate stability, as well as its influential factors in urban riparian zone were discussed. Results indicated that soil physiochemical properties varied significantly with spatial locations. As for mechanical composition, sand particles were dominant in all three sampling sites, and dropped along with rising elevation, especially in SCK. The content of soil organic carbon (SOC), ammonia nitrogen (AN), available phosphorus (AP), available potassium (AK) decreased with increasing soil depth. Among them, the SOC showed WTZ>HSP>SCK, gradually declining along with the progressive river reaches. Soil aggregate stability indices also varied along river flow direction. Both MWD and GMD showed WTZ>HSP>SCK. The K was ranked as SCK>HSP>WTZ, and rose as elevation increased on slope surface. Redundancy analysis indicated that SOC and soil nutrients such as AN, AP, and AK were significantly positively correlated with MWD and GMD, but negatively correlated with K. They were the main factors controlling soil aggregate stability in riparian zone of River Tour Company.

This article examines how Kham Tibetan herders in the eastern Himalaya navigate ecological uncertainty through a form of cosmopolitics grounded in Buddhist worldviews, Bön animistic ontologies, and highland pastoralist practices. Despite increasing exposure to scientific narratives of climate change, everyday engagements with the landscape remain shaped by a more-than-human cosmology in which mountains, weather, animals, plants, and spirits are animated co-actors. Drawing on long-term ethnographic fieldwork, the article develops the concept of Tibetan Pastoral Cosmopolitics to describe the dynamic entanglement of such multiple epistemologies and ontologies. Two interrelated dynamics are foregrounded. First, karma functions as both a moral principle and a material-affective medium. It individuates human and non-human beings while generating ecological and spiritual frictions. Second, pastoralist ecology unfold through reciprocal and struggling relationships with animated landscapes: yaks, caterpillar fungus ( Ophiocordyceps sinensis ), mountain deities, and volatile weather systems are active participants in sustaining or threatening life. These relations generate a situated climate ethics grounded in ritual and ethical calibration. In a time when global climate discourse risks erasing indigenous difference, Tibetan pastoral cosmopolitics offers a compelling ethnographic example of how more-than-human spiritual lifeways inform ecological practice and perception. The article will contribute to ongoing debates in environmental anthropology, more-than-human ethnography, and the anthropology of climate change by foregrounding Tibetan cosmological frameworks as climate strategies in their own right.

Population ageing within the agricultural workforce renders drought adaptation among older farmers an urgent yet underexamined dimension of climate resilience. This study examines how farmers aged 60–69 in drought-prone communities of Buriram Province, Thailand, perceive and respond to drought risk, drawing on social–psychological theories of behavior and decision-making. Using stratified group discussions with older farmers who have more than a decade of farming experience, the analysis indicates that drought adaptation is shaped by the complex interaction of behavioral beliefs, social norms, perceived self-efficacy, and cost–benefit appraisals. Older farmers’ responses are mediated by peer-influenced cognitive processes, including observation, imitation, comparison, and self-regulation, as well as by community norms that reinforce social pressure to maintain traditional farming identities. At the same time, they also apply their own evaluative frameworks to weigh immediate climate threats against the physical and financial costs of altering long-standing practices. This experience-based appraisal determines whether a self-protective strategy is perceived as feasible or too costly within the constraints of their life stage and available resources. Strengthening peer-based knowledge exchange and community-led extension mechanisms tailored to ageing farmers is therefore recommended to align adaptive interventions with these cognitive and social dynamics.

environments could have led to a significant misunderstanding of nitrate aerosol trends and clean-air measure effectiveness.

Heritage-led urban redevelopment is increasingly adopted to advance cultural continuity and social vitality; however, its long-term sustainability is often compromised due to the absence of user-oriented assessment methods. Conventional Post-Occupancy Evaluation (POE) approaches are limited in their ability to capture experiential, social, and participatory dimensions of architectural and urban spaces. This study examines the potential of Virtual Reality (VR) as a participatory POE tool for sustainable heritage redevelopment through the case study of Souq Al Muharraq in Bahrain. A convergent mixed-method approach is employed, integrating immersive VR 360-degree walkthroughs, structured questionnaires, qualitative semi-structured interviews, and expert evaluation. The findings reveal significant discrepancies between design intentions and lived experience, specifically in thermal comfort, circulation, social usability, and informal spatial practices. The study demonstrates that VR supports a user-centered and experiential approach aligned with Sustainable Development Goals (SDGs) 9, 11, and 16. It further proposes a sustainable and cost-efficient framework for architecture and urban projects’ evaluation by enabling early and post-user-centered evaluation of projects to reduce costly revisions and the creation of inclusive, adaptive, and resilient architecture and urban spaces.