Publications

Abstract Urban parks are essential to sustainable cities, providing climate regulation, supporting biodiversity, and offering vital spaces for recreation and overall well-being. At the same time, their soils can act as long-term reservoirs for persistent organic pollutants (POPs), reflecting decades of atmospheric deposition, diffuse urban emissions, and historical land-use practices. This review synthesises current knowledge on the occurrence, sources, and environmental behaviour of priority POPs, including OCPs, PCBs, PCDD/Fs, PBDEs, PFAS, and PAHs, in the soils of urban parks and gardens worldwide. Evidence from multiple regions reveals consistent patterns: urban parks accumulate complex mixtures of legacy and emerging contaminants, reflecting both historical inputs and ongoing urban activities. These contaminants primarily contribute to scenarios of chronic, low-level exposure through the ingestion of soil and dust, inhalation of resuspended particles, dermal contact, and, in some cases, dietary intake when food is cultivated in contaminated park soils. While such exposure pathways have been associated with a range of adverse health outcomes in toxicological and epidemiological studies, the presence of POPs in park soils does not imply that urban parks represent hazardous environments. Instead, it emphasises the importance of proportionate, evidence-based assessments within spaces that yield substantial net benefits to public health. Despite growing research interest, significant gaps remain, including limited understanding of mixture toxicity, insufficient data on temporal trends, a lack of harmonised monitoring strategies, and the absence of exposure scenarios specifically tailored to recreational soils. This review also examines major international and European regulatory frameworks and soil-quality guideline approaches relevant to urban and recreational soils, identifying mismatches between scientific evidence and regulatory practice. By integrating perspectives from environmental chemistry, toxicology, urban ecology, and policy, this review highlights the importance of targeted monitoring and context-specific management strategies to ensure that urban parks remain safe, healthy, and equitable components of increasingly complex urban landscapes.

Abstract <jats:p>Pollution of soils by heavy metals (HM) is a concerning result of anthropogenic activities. Iron (Fe) and silver (Ag) are HM-deemed essential and non-essential for plants and can induce toxicity when in excess. Metallothioneins (MTs) are small Cys-rich proteins involved in HM binding and oxidative stress mitigation. This study focused on Arabidopsis thaliana MTs types I, II, and III involvement in response to increasing concentrations of Fe and Ag in an organ-specific way - shoots and roots - through RT-qPCR analysis 21 days after germination, as well as biometric and biochemical assessments. The in vivo heterologous expression of AtMT2b in Nicotiana tabacum leaves was performed. Both HM reduced plant growth, with Fe accumulating dose-dependently in both shoots and roots, while Ag mainly accumulated in roots, albeit only at the highest concentration in shoots. Fe exposure caused little change in MT expression, whereas Ag strongly induced it in shoots and, to a lesser extent, in roots (particularly AtMT1a and AtMT1c). Biochemical analyses revealed distinct stress responses: Fe increased lipid peroxidation (MDA) and antioxidant compounds (GSH, thiols) mainly in shoots, while Ag triggered oxidative metabolism predominantly in shoots, with elevated HO, MDA, GSH, thiols, and proline levels. Both HM reduced photosynthetic pigments, notably -carotenes with Fe, and chlorophylls, lutein, and -carotenes with Ag. In vivo localisation showed AtMT2b to be cytosolic. Overall, Fe and Ag induced stress in A. thaliana with organ-specific responses, and MTs played a minor role in Fe tolerance but were strongly activated by Ag, especially in shoots.</jats:p>

Abstract The ability to assess molecular binding kinetics in real time is critical for advancing our understanding of molecular interactions in biochemical and biotechnological systems. This work presents a novel optical tweezer (OT)-based method to monitor molecular affinity in real time, focusing on the high-affinity streptavidin-biotin system as a model. Transparent poly(methyl methacrylate) (PMMA) microparticles functionalized with streptavidin were trapped before, during, and after binding with biotinylated bovine serum albumin (biotin-BSA), enabling the analysis of forward-scattered signals to detect nanoscale changes in particle size. By applying the Power Spectral Density method, the friction coefficient of individual particles was calculated, allowing for real-time tracking of binding dynamics and the estimation of the association rate constant (kon approximate to 106M-1s-1). These results are consistent with literature values and demonstrate the potential of this OT-based approach for non-invasive, label-free detection of molecular interactions. Compared to existing techniques, such as atomic force microscopy and cantilever-based sensors, this method offers significant advantages, including real-time monitoring, adaptability to different bioaffinity systems, and compatibility with miniaturized setups. This work establishes a foundation for using OT-based tools to monitor high-affinity molecular interactions in real time. While demonstrated here using biotinylated BSA as a model ligand, future studies will explore the method's applicability to smaller ligands and more subtle surface modifications.

Abstract Hydroponics is an advanced agricultural technique that involves growing plants without soil. Instead, plants are cultivated in a nutrient-rich water solution that provides all the essential minerals they need to thrive, allowing plants to grow either with their roots directly in the solution or supported by inert substrates like pine bark, coconut husk fiber, and rice husk. The solid waste generated from hydroponic cultivation is valuable due to its low cost, abundance, biodegradability, and renewability. These residues are rich in lignocellulosic materials, which can be extracted and refined to produce cellulose and nanocellulose (NC). In this work, cellulose and nanocellulose were extracted from residues of coconut husk fiber and a mixture of pine bark and coconut husk fiber, used in tomato and strawberry hydroponics, respectively. The residues were ground, washed, and chemically treated to obtain cellulose and NC. The chemical process involved several stages: (i) acid treatment, alkaline treatment, and bleaching to isolate cellulose, and (ii) acid hydrolysis followed by ultrasonication to obtain NC. Both materials underwent characterization using various techniques such as TGA, DSC, XRD and FTIR-ATR, which confirmed very low levels of lignin and hemicellulose. Morphological characterization through SEM revealed the presence of micro- and nano-crystals in the cellulose and NC samples, respectively, highlighting the effectiveness of the extraction method. The high purity and quality of the extracted materials make them competitive with commercially available products, suitable for applications in healthcare, food packaging, and automotive industries, while supporting recycling and reuse principles.

Abstract This study investigates spatial distribution and chemical elemental composition screening in soils in Rome (Italy) using X-ray fluorescence analysis. Fifty-nine soil samples were collected from various locations within the urban areas of the Rome municipality and were analyzed for 19 elements. Multivariate statistical techniques, including nonlinear mapping, principal component analysis, and hierarchical cluster analysis, were employed to identify clusters of similar soil samples and their spatial distribution and to try to obtain environmental quality information. The soil sample clusters result from natural geological processes and anthropogenic activities on soil contamination patterns. Spatial clustering using the k-means algorithm further identified six distinct clusters, each with specific geographical distributions and elemental characteristics. Hence, the findings underscore the importance of targeted soil assessments to ensure the sustainable use of land resources in urban areas.

Abstract This work aims to conduct a Life Cycle Assessment (LCA) of seamless leggings produced by a Portuguese textile company, following a “cradle-to-gate” approach. This includes all life cycle stages from raw material production to the packaging of the seamless leggings, ready to leave the company gate. Primary data for the foreground processes were obtained from the actual industrial practices of the Portuguese company, complemented by data from the ecoinvent V3.5 life cycle inventory database and literature sources, primarily for the background processes. The ReCiPe 2016 Midpoint (E) V1.02 methodology was employed to evaluate potential environmental impacts, using the SimaPro V8.5.2 LCA software. Results indicate that the production and spinning of fibers have the highest environmental impacts, mainly due to their high energy consumption. Dyeing operations are more impactful than confection operations, particularly contributing to water use and freshwater ecotoxicity. Therefore, efforts to reduce overall environmental impacts should initially focus on these life cycle stages. Switching the electricity source from the national grid mix to entirely photovoltaic energy resulted in a significant reduction in several environmental impact categories, including a 30% reduction in global warming potential. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

Abstract Herein we report a visible-light-active photocatalytic nanocomposite (NC50:50) prepared from carbon dots (CDs) and TiO2 nanoparticles, which was applied to the photodegradation of organic dyes in water. The CDs incorporated corn stover, a major agricultural waste, and were prepared via hydrothermal treatment. Using a visible- light irradiation source and the dye methylene blue as a representative of the organic dyes class, we observed that a 374 % enhancement of the catalytic performance was achieved by adding CDs relative to bare TiO2. This was possible due to increased visible-light absorption and better photonic efficiency. Tests using reactive species scavengers indicated that three active species (superoxide anion, hydroxyl radicals, and electrons) were responsible for the photodegradation process, differing from bare TiO2 in which only the hydroxyl radical has a relevant role. Photocatalytic degradation was also observed toward Rhodamine B, Orange II and Methyl Orange. Finally, we performed a life cycle assessment (LCA) study to assess and analyse the associated environmental impacts of NC50:50 compared with other alternatives, which revealed that NC50:50 is the alternative resulting in the least environmental impacts. In summary, NC50:50 could, under visible-light irradiation, efficiently remove different organic dyes while incorporating organic waste materials and reducing the impacts associated with their use. We expect that this study provides a base for a more environmentally sustainable design of visible- light-active photocatalysts via waste upcycling.

Abstract This study investigates the structural and transport properties of SDS, CTAB, and SB3-12 micelles in three deep eutectic solvents (DESs), Ethaline, Glyceline, and Reline, using molecular dynamics (MD) simulations. The influence of solvent composition on micelle morphology, interactions, and dynamics was explored, revealing key differences driven by the DES environment. Structural analyses, including eccentricity and radius of gyration, demonstrated that micelle shape and compactness vary significantly depending on the solvent. In Ethaline and Reline, larger micelles showed significant deviations from spherical shapes, while micelles in Glyceline became more spherical and compact, particularly those formed by SB3-12. Radial distribution functions highlighted different levels of micelle-solvent interactions, with SDS showing strong interactions with HBD components and SB3-12 exhibiting prominent self-interaction. According to hydrogen bonding analysis, micelles slightly disrupt the DES hydrogen bond network, with SB3-12 establishing the most significant hydrogen bond connections. The transport property analysis revealed that larger micelles have lower diffusion coefficients, whereas smaller micelles enhance DESs' component mobility. These findings advance the understanding of micelle behavior in DESs and also help in the optimization of DES-surfactant systems for applications such as electrodeposition, nanomaterial templating, and drug delivery. Future research will focus on surfactant interactions with surfaces to further improve these applications.

Abstract Active and abandoned mining sites are significant sources of heavy metals and metalloid pollution, leading to serious environmental issues. This study assessed the environmental risks posed by potentially toxic elements (PTEs), specifically arsenic (As) and antimony (Sb), in the Technosols (mining residues) of the former Pej & atilde;o coal mine complex in Northern Portugal, a site impacted by forest wildfires in October 2017 that triggered underground combustion within the waste heaps. Our methodology involved determining the pseudo-total concentrations of As and Sb in the collected heap samples using microwave digestion with aqua regia (ISO 12914), followed by analysis using hydride generation-atomic absorption spectroscopy (HG-AAS). The concentrations of As an Sb ranging from 31.0 to 68.6 mg kg-1 and 4.8 to 8.3 mg kg-1, respectively, were found to be above the European background values reported in project FOREGS (11.6 mg kg-1 for As and 1.04 mg kg-1 for Sb) and Portuguese Environment Agency (APA) reference values for agricultural soils (11 mg kg-1 for As and 7.5 mg kg-1 for Sb), indicating significant enrichment of these PTEs. Based on average Igeo values, As contamination overall was classified as unpolluted to moderately polluted while Sb contamination was classified as moderately polluted in the waste pile samples and unpolluted to moderately polluted in the downhill soil samples. However, total PTE content alone is insufficient for a comprehensive environmental risk assessment. Therefore, further studies on As and Sb fractionation and speciation were conducted using the Shiowatana sequential extraction procedure (SEP). The results showed that As and Sb levels in the more mobile fractions were not significant. This suggests that the enrichment in the burned (BCW) and unburned (UCW) coal waste areas of the mine is likely due to the stockpiling of lithic fragments, primarily coals hosting arsenian pyrites and stibnite which largely traps these elements within its crystalline structure. The observed enrichment in downhill soils (DS) is attributed to mechanical weathering, rock fragment erosion, and transport processes. Given the strong association of these elements with solid phases, the risk of leaching into surface waters and aquifers is considered low. This work underscores the importance of a holistic approach to environmental risk assessment at former mining sites, contributing to the development of sustainable remediation strategies for long-term environmental protection.