Abstract: Recent offshore hydrocarbon discoveries along the Senegalese–Mauritanian margin increase the need to quantify oil-spill risk under the highly dynamic circulation of the southern Canary Current upwelling system. We investigate seasonal pollutant dispersion along the Senegalese Grande Côte using Lagrangian particle-tracking experiments forced by CROCO ocean model outputs. The analysis focuses on the role of wind-driven circulation, Ekman transport, and upwelling variability in controlling cross-shore and alongshore transport pathways. Results show a strong seasonal contrast. During the cold season (January–May), intensified northerly winds drive coastal upwelling and offshore Ekman transport, enhancing surface divergence and promoting the export of particles away from the coast. This regime limits nearshore accumulation but favors broader offshore dispersion over the continental shelf. In contrast, during the warm season (June–September), weakened upwelling-favorable winds and the establishment of anticyclonic circulation north of the Cape induce onshore transport and coastal retention. Particle-release experiments reveal enhanced trapping and accumulation along the Grande Côte during this period. The Kayar region and the Cape Verde Peninsula exhibit relatively higher exposure during the cold season, whereas the inner shelf along the Grande Côte becomes particularly vulnerable during the warm season. These findings demonstrate that seasonal wind forcing and associated Ekman dynamics exert first-order control on oil-spill pathways. Incorporating this variability into contingency planning is essential, as the inner continental shelf of the Senegalese Grande Côte is a dynamically sensitive, high-risk zone under the warm-season circulation regime.

Abstract: Reliable and timely estimation of air pollution exposure at high spatial and temporal resolution remains challenging in complex urban environments, where pollutant concentrations vary due to traffic emissions, urban morphology, and meteorological conditions. This study presents a physics-informed machine learning framework for near–real-time estimation of NO₂ concentrations at fine spatial scales. The approach combines a limited set of steady-state Computational Fluid Dynamics (CFD) simulations with operational meteorological and air-quality data. CFD simulations under specific wind directions are first used to characterize site-specific dispersion patterns. These outputs are then scaled using hourly meteorological observations to generate physics-based concentration descriptors. A machine learning predictor, implemented using Random Forest and Extreme Gradient Boosting, is trained to refine these estimates by incorporating additional environmental and observational features. The method is applied to a 1 km × 1 km urban district in Antwerp, Belgium, within the FAIRMODE intercomparison framework. Validation against measurements from 105 passive samplers collected over one month shows substantial improvement compared to standalone dispersion modeling, with coefficients of determination up to R² = 0.965 and reduced bias across locations. These findings demonstrate that integrating physical modeling with machine learning enables accurate and computationally efficient high-resolution exposure assessment in urban settings.

Abstract: Nanoplastics are produced abiotically and biotically from larger pieces of plastic. Although nanoplastic toxicity has received more attention recently, its biological effects have not been adequately investigated. In this study, the toxicity of nanoplastics (NPs) with an average size of <80 nm was carried out in the larvae of Artemia nauplii, an indicator organism of the aquatic environment, according to the OECD guideline 202 protocol. As a result, depending on exposure durations (24-96 h) and concentrations (50-300 μg/mL), the survival rate of nano-HDPE treated larvae was significantly reduced (p < 0.05). The larvae took up and internalized nano-HDPE at a concentration of 99.74 µg/mL, which is the calculated LC50 value. There was also a significant increase in biochemical markers in larvae at LC50 (p < 0.05). However, it was observed that this caused oxidative stress, cell membrane damage, limb loss and malformation in larvae treated with nano-HDPE.

Abstract: Chromium is one of the most prevalent toxic heavy metals in the environment and is known to cause cancer, and cellular damage. Various treatments can effectively remove Chromium ion from wastewater. However, majority of those methods are not environmentally friendly. Here, we investigated the efficacy of stem cactus activated carbon (SCAC) and commercial activated carbons (CAC) to remove hexavalent chromium from synthetic and real wastewater. In this study, the stem cactus adsorbent was thoroughly characterized. The effect of initial concentration of Cr (VI), contact time, adsorbent dose, shaking speed, and pH on the adsorption process were examined using Micro Plasma Atomic Emission Spectroscopy and UV-Vis Spectroscopy. The data were analyzed using R-software (version 4.4.3 (2025-02-28)) and Origin (2022). The trends in removal efficiency were examined descriptively using line graph. The adsorption equilibrium isotherms and kinetics models were fitted to the data to evaluate the biosorption mechanisms and compare the sorption capabilities of the two biosorbents (SAC and CAC). Under optimal conditions (0.15g SCAC, pH 2, contact time 60 min, shaking speed 200rpm, and an initial Cr (VI) concentration of 6mg/L), Cr (VI) removal efficiencies reached 98.4% and 99.2% from real and synthetic wastewaters, respectively. The adsorption data fitted both the Langmuir and Freundlich isotherm models, suggesting mixed homogenous and heterogenous surface characteristics on the adsorbent. The adsorption process is an endothermic process and respects the pseudo second order kinetics model. The present study suggests that plant-based adsorbents represent an effective alternative for Cr (VI) ion removal.

Abstract: Communities in Mississippi located near petrochemical refining facilities face ongoing risks from heavy metal contamination in soils, threatening environmental quality, food safety, and public health. This pilot study evaluated the phytoremediation potential of Nerium oleander and cabbage (Brassica oleracea) in a residential fence-line community within the Cherokee Forest subdivision of East Pascagoula, Mississippi, impacted by long- term petrochemical and shipyard activities. Plants were grown directly in contaminated garden soils under natural field conditions. Soil and plant tissue concentrations of lead (Pb), cadmium (Cd), zinc (Zn), and nickel (Ni) were measured using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Phytoremediation effectiveness was assessed through removal efficiency, translocation factor, and bioaccumulation factor. Re- sults showed significant reductions (p < 0.01) in all soil metals, with cadmium removal exceeding 97%. Nerium oleander exhibited substantially higher metal uptake and trans- location capacity than cabbage, achieving a maximum cadmium translocation factor of 9.99 and bioaccumulation factors up to 5.67. In contrast, cabbage showed lower transloca- tion efficiency, indicating limited remediation potential but suitability as a food crop after soil treatment. These findings highlight Nerium oleander as an effective, sustainable, and community-acceptable phytoremediation solution.

Abstract:

Using native tree species, the phytostabilisation of heavy metal contaminants at former mining and industrial sites can provide ways to prevent metal spread and leaching into the environment and bring the sites back into the economic circuit. In this study, mixed afforestations with young trees from seven Central European species showing contrasted autecology (Picea abies, Fagus sylvatica, Acer pseudoplatanus, Alnus incana, Populus tremula, Salix viminalis and Betula pendula) were exposed during five years to mixed soil contamination (Zn/Cu/Pb/Cd = 1349/317/70/8 mg kg⁻¹). The metal uptake, their allocation belowground in root tissues and aboveground, the functional traits and the nutrient responses were compared. Despite high metal availability, all tree species showed low metal uptake and similar metal concentrations in their roots. The mobile metals (Zn, Cd) accumulated in the shoot and foliage of early successional species with acquisitive ecological strategy only, whereas the late-successional species blocked the transfer of all heavy metals from the roots to the aboveground organs. All species showed good tolerance to metal contamination, with large interspecific differences regarding the biomass production and some nutrient concentrations, in apparent relation to the varying species’ ecological strategies and independent of the metal treatment. Zn allocation within fine root tissues could enhance transient spatial and temporal metal immobilisation, especially when associated to protective or defence structures, which also contributed to metal detoxification. Higher transfer of mobile metals to aboveground organs in pioneer tree species was clearly related to their acquisitive ecological strategies, in the context of higher nutrient demand in foliage and lesser defence and protection of vegetative organs. The implications of findings for phytostabilisation applications are discussed.

Abstract: This study presents a monitoring system designed as an integrated surveillance and decision support tool for the terrestrial and the ocean environments. The developed system integrates in situ ocean sensor for monitoring purposes as well as a real-time communication tool for data transfer combined with a power generating module to sustain power for all modules. The system is applied for a period of around six months in different seasons to detect, identify gradients of radioactivity in the atmosphere. The gross gamma-ray intensity as detected by the system was interpreted in qualitative manner according to the rainfall events. The background gamma-ray spectra during dry periods for different seasons are also discussed in terms of seasonality. The results of the analysis offer actionable insights through existing mechanisms to support authorities in rapid response and policy planning related to marine radioactivity issues.

Abstract: Abandoned mine sites pose environmental and public health hazards due to the presence of metals in them. We extend our study beyond merely assessing total elemental contents to evaluate the contamination and potential spread of metals from contaminated mining sites into adjacent and surrounding ecosystems. Rather, we employ geo-chemical fractionation methods to measure the elemental fractions and binding forms of Pb, Cd, Mn, Cu, and Zn. We go on to estimate the mobility of these metals in soils collected from abandoned mine sites. The soil pH of the sites ranges from acidic to slightly acidic (4.88–6.48), exhibits moderate electrical conductivity and has varying cation exchangeable capacities (16.97–29.57 meq/100g). The overall concentrations of Pb, Cd, Mn, Cu, and Zn surpass FAO/WHO standards, suggesting a notable human impact stemming from past mining activities. The geochemical fractionation analyses indicate a higher proportion of Pb (88%) and Cd (75%) are present in the residual fraction, suggesting low mobility and indicating a possible source to be associated with geogenic or the parent material or geological sources. The dominance of Mn (83%), Cu (73%), and Zn (66%), on the other hand, in mobile fractions and non-residual forms, suggests that pollution is possibly traced to anthropogenic activities at the mining sites. The mobility and by extension the ecotoxicology of Pb, Cd, Zn, and Cu, may be tied to changes in pH, salinity (EC), as well as bulk density and porosity of the mining sites.

Abstract: Microplastics (MPs) adsorb hazardous substances and are ingested by a wide range of organisms; therefore, indicators for managing their environmental concentrations are needed. Ideally, threshold values should be based on health impacts. However, the diversity of MPs and the complexity of their environmental behavior make it difficult to establish unified environmental concentration standards. In this study, we propose a threshold for the presence of MPs on sandy beaches based on “visual cleanliness,” derived from the amount of MPs that people find psychologically unacceptable. Three types of MPs were used: white polypropylene (PP), blue PP, and white polystyrene (PS; expanded polystyrene). For defining a narrow-range cleanliness threshold, volume concentration was more appropriate than mass concentration. White particles were expected to be less noticeable because they tended to blend with white shell fragments, which are ubiquitous on beaches. In contrast, blue particles were expected to be less acceptable owing to their rarity. However, we found no difference in unacceptability between white PP and blue PP. The threshold, defined as the volume concentration at which half of the respondents find MPs psychologically unacceptable, ranged from 1 to 2 cm3-MPs/m2-sand. Gender, age, travel time to the beach, and frequency of beach visits did not influence unacceptability. Strong concern about marine plastic pollution and experience in cleaning public spaces were associated with a tendency toward low tolerance for MP contamination on beaches.

Abstract: Industrial emissions and legacy contamination from metallurgical activities can constrain sustainable land use by degrading soil quality and limiting vegetation establishment. This study combines a site-based contamination assessment with an early-stage plant tolerance screening to inform nature-based restoration planning in Central Kazakhstan. Soils were collected around three metallurgical complexes and analysed for heavy metals; exceedance relative to maximum permissible concentrations (MPC) was used to prioritise contaminants of concern. Seven locally occurring plant species were then screened in controlled Petri-dish assays using metal salt solutions (Pb, Zn, Cu, Cr, Cd and Ni), and germination percentage, germination dynamics, seedling shoot length and a growth inhibition index were quantified. Soil results showed elevated metal loads with frequent MPC exceedance, supporting the selection of these metals for biological screening. Plant responses were strongly species-specific: Brassica juncea and Medicago sativa maintained comparatively higher germination and early growth across treatments, whereas Suaeda salsa, Artemisia absinthium and Trifolium repens exhibited very low germination. These findings provide an evidence-based shortlist of candidate species for subsequent soil-based trials (including uptake and stabilisation assessment) and support risk-informed revegetation strategies for contaminated industrial landscapes.

Abstract: Diffuse pollution from agricultural runoff, characterized by intermittent discharges of complex contaminant mixtures—including nutrients, pesticides, and heavy metals (HMs)—poses a persistent threat to global water quality. Conventional "end-of-pipe" strategies often fail to address these decentralized, nonpoint sources. This review examines the evolution of Permeable Reactive Barriers (PRBs) from static, abiotic filters into modern Permeable Reactive Bio-Barriers (PRBBs), engineered as dynamic, fixed-bed biofilm reactors. A key advancement in PRBB efficacy is the exploitation of biofilm plasticity, particularly in response to coexistence with organic and inorganic pollutants. While heavy metals are traditionally viewed as inhibitors, this review synthesizes evidence showing that sub-inhibitory HM levels can act as structural and functional drivers. These metals induce the upregulation of Extracellular Polymeric Substances (EPS), creating a "protective shield" that sequesters metals and confers functional resilience on the microbial consortia responsible for nutrient removal and pesticide biodegradation. The review analyzes contaminant removal mechanisms, highlighting the bio-chemo synergy between reactive media and biofilms, and proposes a classification framework based on target contaminants, media, and technological integration. Significant focus is placed on emerging hybrid multi-media systems designed to protect the "biological engine" from toxic metal shocks, alongside the integration of artificial intelligence for predictive control. While challenges in hydraulic sustainability and field validation remain, PRBBs represent a compact, low-energy, and scalable eco-technology. They offer a strategically targeted solution within the Nature-Based Solutions toolkit for building resilient protection of aquatic ecosystems at the critical land-water interface.

Abstract: This study evaluated the seasonal variability, origin, and ecological risk of heavy metals in the Pom-Atasta lagoon system, a tropical estuary in southeastern Mexico subject to increasing anthropogenic pressure. The main objective was to determine how seasonal changes influence the distribution, bioavailability, and risk of metals in sediments and benthic organisms. Thirty sampling stations were monitored during dry, rainy, and north wind seasons. Sediment concentrations of As, Cd, Cr, Ni, Pb, and V were measured, and bioaccumulation was assessed in the bivalve Rangia cuneata. Ecotoxicological risk was evaluated using the Adverse Effects Index (AEI), Toxic Risk Index (TRI), and Potential Ecological Risk Index (ERI). Results showed higher metal concentrations during the rainy and north wind seasons, likely due to increased runoff and sediment resuspension. Cr and Ni exhibited the highest enrichment, with values ​​from 115.0 to 130.4 µg g-1 and from 60.5 to 75.9 µg g-1, respectively. The Ni showed the highest bioaccumulation factor (BSAF > 1.51) in R. cuneata, indicating high mobility and environmental availability. Weak correlations among some metals (As, Cr, Pb) suggest mixed natural and anthropogenic sources. TRI values indicated low to moderate toxic risk, and ERI classified most sites as low risk (ERI <60) at several stations. Organic carbon levels remained within tolerable limits (<10%) for benthic fauna. These findings highlight the role of seasonal dynamics in metal distribution and confirm R. cuneata as a suitable bioindicator for monitoring ecological health in tropical estuarine systems.

Abstract: Ambient air pollution significantly contributes to respiratory illnesses, yet little is known about how industrial emissions are linked to preventable hospitalizations across atmospheric basins in middle-income countries. This study develops a basin-based geo-matics framework to examine the spatial and temporal relationship between industrial pollutants and age- and sex-adjusted avoidable hospitalizations for community-acquired pneumonia (PQI 11) in Mexico from 2013 to 2020. Using state-level data grouped into eight macro-regions, we combine bivariate choropleth maps, Pearson correlations, linear regression, and longitudinal time-series analysis to identify spatial clusters of high risk and to estimate regional sensitivities to changes in PM2.5, SO2, NOx, and volatile organic compound emissions. The findings reveal notable regional differences: northern border states and the Mexico City metropolitan basin form persistent high–high clusters where elevated emissions coincide with high PQI 11 rates, while coastal and peninsular regions show lower hospitalization burdens despite medium emission levels. Although national industrial PM2.5 emissions decreased over the study period, several macro-regions—particularly CDMX_Edomex, Centro, and Centro Norte—experienced significant increases in avoidable hospitalizations and decoupled emission–health patterns. Correlation matrices and regression slopes suggest that the strength and even direction of links between pollutants and PQI 11 vary across macro-regions, with emission-responsive patterns in Centro Norte and weak or inverse relationships in Peninsula and Pacifico Sur. These findings demonstrate that national averages obscure critical spatial disparities and highlight the value of basin-based geomatics approaches for regional air-quality governance, spatial decision support, and primary-care planning aimed at reducing preventable respiratory hospitalizations.

Abstract: Petroleum hydrocarbon contamination in soil is difficult to remediate due to strong adsorption and limited bioavailability. In this study, a combined remediation strategy integrating a silica gel-loaded, iron-catalyzed sodium percarbonate composite (SPCSF) with Bacillus subtilis ATCC 11774 was developed for diesel-contaminated soil. The remediation performance of chemical oxidation, microbial remediation, and their combined application was systematically evaluated. The simultaneous SPCSF–microbial treatment achieved the highest removal efficiency, reaching 65.1% after 31 d, which was markedly higher than that of chemical oxidation (22.5%) or microbial re-mediation alone (31.1%). SPCSF played a dual role in the system: it generated reactive oxygen species for the oxidative breakdown of long-chain hydrocarbons into bioa-vailable intermediates, and it regulated soil pH and oxidation–reduction potential, creating favorable conditions for microbial activity. In turn, Bacillus subtilis facilitated Fe(II) reduction and stabilization, sustaining the Fe(II)/Fe(III) redox cycle and thereby enhancing hydroxyl radical generation in Fenton-like reactions. Spectroscopic analyses (three-dimensional fluorescence spectrum, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy) demonstrated that the combined treatment promoted the transformation of petroleum hydrocarbons into carboxyl-rich organic matter, providing molecular-scale evidence of effective mineralization. This synergistic interaction between chemical oxidation and microbial degradation offers an efficient and environmentally compatible approach for petroleum hydrocarbon–contaminated soil remediation.

Abstract: Rationale: The Niger Delta, one of the world’s most resource-rich regions, has long borne the negative impacts of oil extraction, resulting in persistent pollution, ecosystem collapse, and infrastructural neglect. These issues, while well-documented, are rarely framed as a public health emergency requiring systemic intervention. The region’s environmental degradation is not merely an ecological concern but a slow-moving public health crisis, driven by governance failures, regulatory fragmentation, and economic inequalities embedded in the extractive system. Objective: This study aims to reframe environmental degradation in the Niger Delta as a public health emergency and propose the Integrated Environmental-Health Accountability Framework (IEHAF) to address the multi-dimensional health impacts of pollution. The objective is to offer a new approach that links ecological damage to morbidity, mortality, and socioeconomic hardship, while emphasizing interdisciplinary research and policy reform. Method(s): Drawing from environmental epidemiology, hydrochemistry, biodiversity loss, and health systems research, this paper synthesizes existing knowledge to develop the IEHAF framework. It focuses on three domains: (1) environmental toxicity and ecological collapse, (2) human exposure, vulnerability, and adaptation, and (3) institutional accountability and policy inertia. These domains guide an analysis of how pollution exposure leads to health inequities and long-term socioeconomic consequences. Results: The IEHAF framework emphasizes that pollution is not only an environmental issue but a central determinant of health inequity. By linking environmental, health, and economic systems, the framework provides a holistic view of the long-term effects of extractive practices. It reveals how institutional inertia and policy fragmentation have worsened the crisis, deepening intergenerational poverty. Conclusions: Reframing environmental degradation as a public health emergency is vital for shifting policy responses from reactive to proactive. IEHAF offers a structured approach to integrate environmental governance, health surveillance, and social protection, essential for sustainable development in the region. Recommendations: Policymakers must adopt IEHAF in regulatory frameworks, integrate health outcomes into extractive licensing, and ensure systematic health screenings for affected communities. Researchers should prioritize long-term evaluations of IEHAF, while civil society should advocate for community-led environmental monitoring and corporate accountability. Significant Health Statement: Chronic exposure to pollutants in the Niger Delta leads to long-term health burdens, including gastrointestinal disorders, respiratory diseases, and neurological damage. The IEHAF framework emphasizes the need for early intervention, health surveillance, and integrated policies to protect vulnerable populations, making the recognition of pollution as a central health determinant both a policy necessity and a moral imperative.

Abstract: Plastic pollution constitutes a critical planetary health challenge, undermining the integrity of Earth systems while generating cascading harms to human health, livelihoods, and social equity particularly in low- and middle-income countries. Conventional top-down regulatory and technological responses have proven insufficient to address the complexity of plastic pollution, often excluding those most affected from decision-making and solution design. This paper examines how democratizing plastic governance through grassroots leadership can advance planetary health by simultaneously protecting ecosystems, improving human well-being, and strengthening socio-ecological resilience. Drawing on empirical evidence from the #RestorationX10000 initiative led by Community Action Against Plastic Waste (CAPws), this paper documents implementation processes and outcomes achieved between 2021 and 2025 across 71 impacted communities in 21 countries spanning Africa, Asia-Pacific, and Latin America. The initiative was designed to empower 10,000 youths and women as community leaders, practitioners, and advocates by equipping them with leadership, technical, and policy engagement skills to drive systemic change in plastic governance and circular economy practice. Using a transdisciplinary, community-based action research approach aligned with planetary health principles, the initiative integrates capacity building, citizen science, circular economy interventions (collection, sorting, repair, reuse, repurposing, and recycling), and policy advocacy. Quantitative and qualitative evidence demonstrates that grassroots-led interventions can simultaneously reduce plastic leakage, create decent green livelihoods, and strengthen environmental governance. We argue that inclusive, community-centered plastic governance is not only an environmental intervention but a planetary health strategy, offering policy-relevant insights for national plastic action plans, extended producer responsibility frameworks, and global negotiations toward a legally binding instrument on plastic pollution.

Abstract: Water supplies contaminated by heavy metals pose a serious threat to human health, especially in areas without access to centralized testing facilities. While copper is a necessary heavy metal in trace levels, high concentrations can have detrimental effects on health, such as oxidative stress, cognitive impairment, and liver damage. Due to their expense, complexity, and reliance on laboratories, conventional detection tech-niques are accurate but unsuitable for real-time, dispersed deployment. Machine learning offers a potent solution to these constraints by facilitating the automatic, pre-cise, and quick interpretation of complicated sensor data. It makes it possible to make decisions in real time without requiring a large laboratory infrastructure. In this work a dual-mode optical sensor was developed using the colorimetry and fluorometry images of carbon dots embedded in hydrogels with the Cu2+ concentration of 0, 20, 50, 100, 200, and 500 μM. Data augmentation was used to expand the RGB picture dataset for each modality, and these data were interpolated to provide re-sponses at 1 µM intervals (0–500 µM). We trained a comprehensive set of supervised machine learning models including Logistic Regression, Support Vector Machines, Random Forest, and XGBoost to categorize water samples into five risk-informed quality levels. The system achieved classification accuracies exceeding 96%. Further-more, we built a simple user interface to make the system practically deployable in mobile phone. Together, these results demonstrate a scalable, interpretable, cost-effective, and quick solution for real-time water quality monitoring in re-source-constrained environments.

Abstract: Heavy metal contamination of foods remains a persistent global challenge for food safety and public health, driven by industrialization, mining activities, intensive agriculture, and ongoing environmental degradation. This Scopus-based descriptive review synthesizes peer-reviewed literature on the occurrence of priority toxic metals—arsenic, cadmium, lead, mercury, and nickel—in food matrices, with emphasis on contamination pathways, analytical detection strategies, and documented human health effects. The reviewed studies reveal widespread accumulation of heavy metals in staple foods, including cereals, vegetables, seafood, and processed products, with concentrations frequently approaching or exceeding international regulatory limits, particularly in regions exposed to strong anthropogenic pressure. Conventional laboratory-based techniques, such as atomic absorption spectrometry and inductively coupled plasma methods, remain the reference standards for quantitative determination and regulatory compliance; however, their application to large-scale or continuous monitoring is often constrained by cost, infrastructure, and operational complexity. Consequently, increasing attention has been directed toward emerging detection approaches, including portable X-ray fluorescence, Raman/SERS spectroscopy, electrochemical biosensors, electronic tongues, and in situ magnetic measurements, as complementary tools for rapid screening and field-based surveillance. Among these, environmental magnetism and in situ magnetic techniques stand out as non-destructive, low-cost proxies capable of identifying metal-associated particulate contamination linked to food production systems. Chronic dietary exposure to heavy metals is consistently associated with neurotoxicity, nephrotoxicity, carcinogenicity, and oxidative stress, underscoring the need for integrated, multi-tiered monitoring frameworks to support early detection, risk assessment, and prevention.

Abstract: Soil contamination by heavy metals (HMs) [or potential toxic elements (PTEs)] poses serious risks to ecosystems and human health. Metals persist in the environment and can reach groundwater and freshwater as the food-chain. In soils, anthropogenic inputs dominate over geogenic sources; unfortunately, HMs cannot be easily destroyed by biogeochemical processes as other contaminants. Metal mobility is strongly controlled by factors such as pH, mineralogy, and erosion processes that transport metal‑bearing clay fractions. Erosion due to wind and water can transport soil clay component, clay can usually bind contaminants such as HMs. Remediation technologies are broadly classified as ex-situ and in-situ, with trade‑offs in cost, duration, and site disruption; the optimal choice depends on contaminant speciation, concentration, soil properties, and climate. In-situ remediation using phosphates are among Nature based Solutions (NbS), waste from phosphatic rock mine activity and/or from fertilizer industry is a way to apply the circular economy principle; it is a cost-effective stabilization strategy for mobile and exchangeable fraction of metals. Using waste material is a tool suggested from the circular economy, so waste is becoming a valuable resource. This study evaluates the immobilization efficiency and mechanisms of four phosphate materials applied to a brownfield site, combining chemical speciation analyses and leaching tests to assess reductions in metal mobility and potential for safe site reuse. Results clarify which phosphate amendments most effectively stabilize target HMs and inform practical, circular remediation strategies for contaminated urban soils.

Abstract: The concentrations of PTEs and Fe₂O₃ increase from the sand fraction to the silt fraction, although the magnitude of this increase is not uniform (Zn > Cu > As > Pb), while SiO₂ content is not affected by particle size. In general, PTE concentrations are lower in wet samples than in dry samples. The ratio of the element concentration in the wet sample to that in the air-dried sample, together with the gravimetric moisture content (%), were plotted in central scatter plots, which allowed the identification of outliers. The inverse relationship observed between the concentration of certain elements and moisture content may be explained by the geochemical characteristics of the sample. Moisture in both manually and mechanically ground samples influences analytical ac-curacy, even when the processing time is identical. Triplicate samples indicate small-scale heterogeneity driven by post-depositional alteration of the tailings, as well as element associations (e.g., Fe₂O₃–As) dictated by the mineralogical composition of the source material (e.g., arsenopyrite).