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We present an original opto-electrochemical approach for the real-time conversion of low faradaic currents into electrochemiluminescence (ECL) signals. Under potentiostatic control, the electrochemical reaction of interest occurs at a working ultramicroelectrode (UME), while a second UME, used as a counter electrode, functions as an optical reporting site. ECL emission is generated at this electrode by a luminol derivative with H2O2. We demonstrate a nearly perfect linear correlation between the current generated at the working electrode and the ECL intensity emitted from the counter electrode, thereby validating the current-to-ECL conversion principle for both steady-state and transient signals. Furthermore, we successfully apply this conversion scheme to detect electrocatalytic nanoimpact events. Single platinum nanoparticle collisions produce discrete current spikes that are translated simultaneously into ECL bursts. These findings prove that current-to-ECL conversion is a promising strategy for the high-bandwidth, high-sensitivity detection of faradaic events in advanced nanoelectrochemistry applications.

Exposure to engineered nanomaterials (ENMs) at the workplace can adversely affect human health via inhalation. Occupational exposure limits (OELs) for specific ENMs remain scarce due to a lack of nano-specific data and consensus on the most appropriate dose metric for exposure assessment. In 2022, recommendations were provided on how to derive Health-based Nano Reference Values (HNRVs) for different categories of ENMs. Here, we have updated these recommendations based on new insights and information and changed the name into Health-based Nanomaterial Guidance Values (HNGVs) to distinguish from existing pragmatic Nano Reference Values. Using expert consultation, we derived a general HNGV for spheroidal biodurable ENMs with relatively low substance-specific toxicity. Benchmark ENMs were selected based on criteria such as low dissolution rate in physiologically relevant media and absence of substance-specific toxicity. For these ENMs, several human health endpoints were evaluated and pulmonary inflammation was selected as the critical effect. Persistent inflammation is considered an important driver for chronic adverse effects and keeping exposures below levels causing neutrophil influx is expected to protect against effects such as ENM-induced lung fibrosis and lung cancer. Subsequently, no-observed-adverse-effect-concentrations (NOAECs) or lowest-observed-adverse-effect-concentrations (LOAECs) were derived from high quality in vivo studies to provide a range of Derived No Effect Levels (DNELs). Based on these DNELs, we recommend an HNGV value of 4 μg/m3 averaged over an 8-h workshift. This HNGV can be practically assessed at the workplace for ENMs that have a clear chemical signature such as metal-based ENMs.

Nanocellulose materials, including cellulose nanofibers and cellulose nanocrystals, are promising renewable materials with diverse industrial applications. However, potential worker exposure during the handling of dry powders remains a concern. In this study, the dustiness and aerosol characteristics of nine nanocellulose powders were evaluated using the small rotating drum method specified in EN 17199. Aerosolized nanocellulose was characterized using real-time instruments, gravimetric analysis, and microscopic observation of filter-collected particles. All samples generated respirable particles, with mass-based dustiness indices ranging from 10 to 300 mg/kg, comparable to those of other nanomaterials. Aerosolized nanocellulose did not appear as isolated fibers but rather as aggregated or agglomerated particles approximately 0.1-10 μm in size. These findings suggest that, under conditions represented by the rotating drum method, aerosolized nanocellulose predominantly appears as particulate matter rather than isolated fibers. Nonetheless, emission and exposure control measures can be necessary when handling dry nanocellulose powders, given the magnitude of their mass-based dustiness indices. The performance and limitations of portable aerosol instruments were also assessed. Optical particle sizer measurements were occasionally influenced by artifacts that may arise from high concentrations of particles larger than the respirable size range, while dust monitors tended to underestimate concentrations for samples containing a large fraction of coarse particles. Despite these limitations, these instruments can provide useful information for workplace safety management when their constraints are taken into account. Overall, this study provides a scientific basis for developing effective exposure assessment and control strategies to support safe handling of nanocellulose powders in occupational environments.

The role of microplastics as vectors for horizontal gene transfer (HGT) of antibiotic resistance genes (ARGs) is increasingly recognized. This study investigated whether bio-based microplastics, often promoted as environmentally friendly alternatives, exhibit similar or enhanced HGT potential compared to conventional plastics. We examined the HGT rates of the trimethoprim resistance gene (dfrA1) and tetracycline resistance gene (tetA), carried on a broad-host-range plasmid, among Escherichia coli (donor) and Vibrio parahaemolyticus, Pseudomonas sp., or a natural lake microbial community (recipients). Four bio-based polymer types-polylactic acid (PLA) granules, commercial PLA, high-density polyethylene (HDPE) granules, and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)- were compared with two conventional microplastics, polyethylene terephthalate (PET) and bottle-derived HDPE. The bio-based microplastics exhibited significantly higher HGT frequencies, with a 21-48-fold increase compared to control chitosan in single-strain experiments and a 13-fold increase within the lake microbial community. 16S rRNA amplicon sequencing revealed distinct bacterial community compositions colonizing different microplastic types in the lake water. The transconjugant communities, indicative of successful HGT events, were strongly influenced by microplastic type. While Nannocystis was generally dominant, the PLA (granule) microplastic exhibited a unique profile dominated by Candidatus Megaira and Niveispirillum. Additionally, Flavobacterium and Fluviicola were uniquely detected as transconjugants on HDPE (granule). These findings demonstrate that bioplastics have a significant influence on the selective enrichment of specific transconjugant genera, suggesting a prominent role of microplastics, particularly bio-based plastics, in shaping ARG dissemination within complex microbial ecosystems. We recommend a comprehensive risk assessment of bio-based plastics, particularly their potential to enhance the spread of ARGs, before their widespread implementation in consumer products.

Nanoplastics (NPs) and lead (Pb), as emerging environmental pollutants, have been rarely studied in terms of their combined effects on crop growth and metabolic processes under low-dose co-exposure conditions. This study simulated rain-mediated co-exposure of maize seedlings to NPs and Pb at environmentally relevant concentrations (400 μg/L) to elucidate the metabolic responses in leaves and the dynamics of phyllosphere microbial communities. Short-term exposure (45 days) to NPs and Pb did not significantly impair maize seedling growth; however, it induced the accumulation of essential macronutrients in leaves. The metabolic adaptation of maize leaves to NPs and Pb exposure was characterized by a reduction in carbon metabolic flux coupled with an enhancement in lipid metabolic flux. Furthermore, plants responded to co-exposure by activating key metabolic pathways such as those involving ABC transporters, nucleotide metabolism, and amino acid metabolism. Concurrently, the phyllosphere microbiome exhibited structural reorganization, with enrichment of stress-tolerant microbial taxa (e.g., Acidobacteria, Chloroflexi), activation of microbial redox systems, and enhanced capacity of the leaf microbiota to adapt to NPs and Pb exposure. The findings offer theoretical insights into assessing agricultural environmental impacts associated with combined exposure to emerging pollutants, phyllosphere microbial ecology, and plant stress resistance.

Plastic production continues to rise in 2025, despite environmental concerns and growing evidence pointing to its adverse impact on human health. Our knowledge of how micro- and nano-plastics affect brain health is, however, still in its infancy. To understand how neurons respond to stress caused by plastics, we exposed primary neurons to polystyrene nanoplastics (PS-NPs). We evaluated effects of the three different sizes of PS-NPs (50, 100, and 250 nm) at concentrations ranging from 0.05 μg/ml to 1 μg/ml. The exposure, relatively low in the tested concentrations and short in the exposure regimen (24 h), did not lead to impairments in neuronal metabolism. However, confocal imaging confirmed the uptake of 250 nm particles by neurons. Despite the lack of metabolic effects, the treatment contributed to neurite elongation in a size-specific manner: the effects were observed upon 50 nm PS-NPs treatment, but not when challenged by the 250 nm particles. Furthermore, subtle but statistically significant changes in the neuronal transcriptome were induced by the smaller, but not larger particles. Additionally, electrophysiological measurements of firing rate and spike amplitude at the time points of 2 and 24 h were not affected by the PS-NPs treatment. These findings highlight the importance of focusing further research specifically on nanoscale plastic particles in the context of brain health.

Biodegradable mulch microplastics (BMPs), such as PBAT and PLA, are widely used in agriculture but can persist in soils and carry coexisting pesticides like dinotefuran (DIN). Despite its widespread use, DIN's environmental fate and microbial toxicity remain insufficiently understood. This study explores the adsorption behavior of DIN on PBAT and PLA and assesses the toxicity of MPs‑neonicotinoid complexes. To provide a more comprehensive understanding, two structurally related neonicotinoids, imidacloprid (IMI) and clothianidin (CLO), were included as comparative references. Adsorption kinetics and isotherms were measured, along with multi-scale characterization (SEM, XRD, FT-IR, XPS, contact angle). The results were integrated with Escherichia coli (E.coli) inhibition assays to assess microbial toxicity. PBAT exhibited a rougher surface with lower crystallinity (7.8% vs 17.1%), and greater hydrophobicity (contact angle 107.7° vs 92.9°) compared to PLA. This increased hydrophobicity likely contributed to the higher adsorption capacity of PBAT for DIN, as confirmed by Langmuir isotherm fitting (Qm ≈ 15.2 mg·kg-1 for PBAT vs Qm ≈ 4.69 mg·kg-1 for PLA). FT-IR/XPS indicated hydrogen-bonding/dipole interactions acting cooperatively with hydrophobic association. Increasing CaCl2 (0-0.1 mol·L-1) enhanced adsorption while NaCl produced a biphasic response, that is low-level promotion, mid-high suppression. MPs-DIN mixtures more strongly inhibited E.coli than single exposures. These results identify BMPs as potential vectors of neonicotinoids and highlight polymer chemistry and environmental modulators in co-exposure risk assessments.

Tire particles and their associated leachates represent emerging microplastic pollution of growing concern. The accumulation of tire-derived pollutants beside road agricultural systems remains poorly characterized, yet species-specific responses to these pollutants also remain poorly understood. This study investigated the differential impacts of tire particles and tire leachate on germination, plant growth, photosynthetic function, and oxidative stress response in two ecologically important crops. Mung bean (Vigna radiata) and tomato (Solanum lycopersicum) were exposed to tire particles (0.1, 1, and 10 g/kg) and tire leachate (10 %, 20 % and 30 %) in soil medium under controlled greenhouse conditions. The tomato plant exhibited superior resistance, mounting a robust, induced superoxide dismutase (SOD) response that successfully mitigated systemic stress and maintained growth. Tire leachate exposure in mung beans causes high Molondialdegyde (MDA) accumulation and significant chlorophyll degradation. This damage coincided with the signifying failure of the antioxidant defense system. Tire-leachate significantly alters soil dynamics, increasing available nitrogen in mung bean soil while causing phosphorus immobilization in tomato soil, demonstrating complex tire-derived contaminant soil-plant interactions. Principal components analysis (PCA) shows a distinct metabolic fingerprint for each treatment, inducing fundamental biochemical reorganization in both species. This study demonstrates that tire contamination effects are highly species-dependent, with mung bean roots being sensitive and inhibition, while tomato growth remained stable, despite clear internal stress. The findings highlight that the highly bioavailable leachate fraction poses the most acute threat to plant health and underscore the critical need for species-specific risk assessment for tire-derived contamination.

Dextran-functionalized graphene oxide nanoplatelets (GONP-Dex) have demonstrated potential for use in diagnostic imaging and as MRI contrast agents, however, their toxicology on human exposure needs to be carefully assessed. To date, no study has explored their effects on human melanocytes, which are melanin-producing cells conferring multiple biological benefits in the skin, ears, eyes, hair, oral cavity, and brain. GONP-Dex (6.25-100 μg/mL) was examined for cytotoxicity on melanocytes from lightly pigmented (LP) and darkly pigmented (DP) human skin for a 48-h duration by trypan blue exclusion assay and Alamar Blue assay, while the cellular membrane integrity was tested using LDH assay. GONP-Dex impaired metabolic activity of LP and DP cells without lowering cell counts. LP and DP cells exposed to GONP-Dex showed higher cellular melanin in the absence of any alteration of cellular tyrosinase activity. However, GONP-Dex showed a concentration-dependent suppression of melanogenic differentiation; both dendrite numbers and lengths were inhibited in LP and DP cells, with a greater susceptibility in DP cells, indicative of the capacity of GONP-Dex to impair melanin export function. GONP-Dex induced oxidative stress in LP and DP cells by increasing intracellular reactive oxygen species (ROS), lowering mitochondrial membrane polarization (MMP), and augmenting nitrite production. Together, our novel results demonstrate a proof-of-principle study into the melanocytotoxic impact of GONP-Dex. Future studies to examine the cytotoxic effects of GONP-Dex using a physiological cell model consisting of melanocyte and keratinocyte coculture and a 3D skin tissue equivalent will help in further validating cytotoxicity.

Nano-impact electrochemistry (NIE) probes electrochemical function one nanoparticle at a time. Freely diffusing particles stochastically collide with an ultramicroelectrode, and each impact produces a current transient that reports single-entity reactivity, transport and transformation. In this review, we place the impact waveform and its data processing at the centre of the discussion and use them as a common language across systems. We describe how chronoamperometric traces are transformed into standardized observables (event counts, peak or step currents, charge, lifetimes, and waiting times), and how these, in turn, enable the extraction of electron transfer kinetics, turnover metrics and transport parameters. We then connect characteristic waveform shapes to mechanistic pictures for both pure electron transfer and coupled ion-electron transfer, using a selector framework in which potential, transport geometry, local composition and reaction timescale determine which reaction pathways are expressed. Multi-collision trajectories, confinement and adsorption/ejection are discussed as elements of a nanoparticle lifecycle. Finally, we highlight how external stimuli and multimodal couplings extend NIE toward establishing correlations between structure, environment and activity and propose a roadmap that outlines key directions and challenges for advancing NIE from studies of model nanoparticles to a broadly applicable tool for complex systems and device-level design.

Mechanical recycling and other processes involved in the end-of-life treatment of 3D-printed plastic polymers can lead to the generation of micro- and nanoplastics (MNPs). As the use of these materials continues to grow, the mechanical degradation of plastics from 3D printing may increase human exposure to MNPs, raising concerns about potential health risks for users and environmental impacts. One of the main routes of exposure to MNPs is via inhalation. For regulatory purposes, most of inhalation studies have been performed using rodents and following the OECD TG 412, however, these models do not accurately mimic the physiology of the human pulmonary system. As alternative, New Approach Methodologies (NAMs) based on human in vitro models have been used lately, providing simple and valuable, and physiologically relevant tools for research. In this work, simple in vitro models using Calu-3 and TK6 cells were exposed for 24 h (acute) and the advanced primary human epithelial MucilAir™ model was exposed for 24 h (acute) and 28 days (sub-acute, adapting the OECD TG 412) to MNPs made of polypropylene (PP), polycarbonate (PC), PP + silver nanoparticles (PP + Ag) and PC + single wall carbon nanotubes (PC + SWCNT). The results showed no significant toxicity of MNPs in acute exposures using the Calu-3 and TK6 models. In contrast, significant effects were observed along time after acute and subacute exposure of MucilAir™ to the different MNPs. These results indicate that robust in vitro models such as MucilAir™ may represent a valuable NAM for acute and sub-acute inhalation toxicity studies.

Micro and nanoplastics are ubiquitous and can lead to adverse biological effects in exposed organisms. Organisms can also be co-exposed to plastics along with synthetic chemicals. In this work, using the NRC Zebrafish Embryo Toxicity test, we evaluated the potential toxicity of different sized plastic particles, along with the effects of combining them with the known toxicants, triphenyl phosphate, tetrabromobisphenol A and fluoxetine. Following chemical/plastic exposure, morphological abnormalities and behaviour were recorded, along with the chemical uptake of the toxicants by the larvae. The PS sphere particles used (0.42, 2.25 and 8.87 μm) exhibited no significant effects on larvae at the environmental concentrations tested (0.05-50 μg/mL) including no changes in larval behavioural activities. However, the presence of the micro/nanoplastic particles did increase the overt toxicity of the chemicals by changing their EC50. Additionally, for all three chemicals, some plastic sizes decreased larval behaviour during the baseline or first light-dark period. Plastic particles did not modify the chemical uptake by the larvae. This suggests that enhanced toxicity caused by the plastics is not linked to changes in chemical uptake, metabolism, or excretion as hypothesized. Additional studies are necessary to better understand the role of plastic particles in a multiple stressor environment.

Microplastic (MP) pollution represents an emerging threat to aquatic ecosystems; yet, most studies remain restricted to isolated biomarker comparisons, without addressing how these pollutants reorganize organisms' systemic properties. In this study, we investigated the effects of naturally aged polypropylene microplastics (NAPP-MPs) - a highly abundant and environmentally relevant polymer - on adult Danio rerio, a recognized model organism in ecotoxicological studies. Fish were exposed to 4.5 mg/L of NAPP-MPs for 15 days and assessed using a biomarker panel that encompassed oxidative and nitrosative stress, antioxidant defenses, neurochemical and endocrine parameters, and digestive protease activities. We observed substantial particle bioaccumulation and consistent biochemical alterations, including increased production of reactive oxygen species, elevated levels of malondialdehyde and nitric oxide, activation of antioxidant enzymes such as superoxide dismutase and catalase, and enhancement of non-enzymatic antioxidant defenses, as measured by the DPPH method. Moreover, we detected elevated concentrations of dopamine, serotonin, and cortisol, as well as increased acetylcholinesterase activity and intensified actions of the digestive proteases trypsin and chymotrypsin. Beyond mean-level differences, we applied a multiscale analytical framework-including criticality analysis, signed networks, information theory, energy landscapes, and Bayesian causal modeling with bootstrap-which revealed that NAPP-MPs shift biochemical systems from adaptive critical regimes to less stable and fragmented states, characterized by loss of cohesion, reorganization of informational flows, and altered functional hierarchies across regulatory modules. Collectively, our results demonstrate that NAPP-MPs not only trigger discrete biochemical responses in zebrafish but also reshape the systemic architecture of homeostasis, undermining both stability and adaptive plasticity. Thus, our study advances the field by integrating innovative methodologies into MP ecotoxicology, providing a conceptual and methodological framework that broadens understanding of their risks and supports more realistic, complex environmental assessments.

Selenium is a vital trace element for human health, but its distribution in European arable soils is often deficient. Selenium nanoparticles (SeNPs) represent a promising solution for biofortification due to their slow-release properties and reduced toxicity. However, their environmental behavior is dictated by interactions with soil organic matter (SOM). This study presents a comprehensive investigation of the physicochemical behavior of green-synthesized SeNPs (using yeast and soapwort extracts, and orange juice) within complex soil matrices. Utilizing an advanced analytical toolkit, including single particle inductively coupled plasma mass spectrometry (spICP-MS/MS), asymmetric flow field-flow fractionation (AF4-DLS/MALS), and capillary electrophoresis (CE-ICP-MS/MS), we characterized nanoparticle stability, aggregation, and the formation of the "eco-corona". HPLC-ESIMS/ MS was further employed to identify specific SOM components, such as lignins, tannins, and peptides, responsible for surface interactions. Results indicate that the interaction of nanoparticles depends on their surface modification and, therefore, on the method of synthesis. SeNPs synthesized with orange juice exhibit superior stability, while specific SOM fractions and high salinity significantly drive aggregation and dissolution. This study provides critical insights into the ligand-mediated processes that govern the lifecycle of SeNPs in agricultural systems.

Plastic, used in almost all everyday products, is a major source of pollution, particularly in the form of micro- and nanoplastics (MNPs). MNP impact on health, particularly on the digestive tract, is still poorly understood, especially in vulnerable populations such as those suffering from inflammatory bowel disease. The aim of this study was to assess the in vitro toxicity of nanoplastics (NPLs) from a biodegradable polymer, polycaprolactone (PCL), both in its pristine state and after accelerated weathering in environmental conditions, the latter resulting in the release of potentially toxic PCL oligomers. To do so, we used in vitro models of genetic susceptibility to Crohn's disease (CD), consisting in co-cultures of HT29-MTX cells with Caco-2 cells engineered to express either wild-type (WT) or mutated nucleotide-binding oligomerization domain 2 (NOD2), representative of healthy individuals (Caco-2 NOD2WT) or individuals with susceptibility to CD (Caco-2 NOD21007fs). Physicochemical transformation of PCL NPLs upon weathering were characterized. Cells were exposed to pristine and aged PCL NPLs and their cytotoxicity, genotoxicity, inflammatory potential, impact on the cells' redox balance and unfolded protein response, as well as on the epithelial barrier integrity were evaluated. Results show that accelerated weathering increases the crystallinity and leads to fusion of PCL NPLs. PCL NPLs accumulate inside cells where they degrade and release some PCL oligomers. However, in the tested conditions, PCL particles, both pristine and aged, do not show any overt toxicity in both cell systems, irrespective of particle size and weathering status. These data confirm that PCL NPLs, may they be intact or partially dissolved, show only mild toxicity to colon cells, upon acute, short-term exposure of Caco-2 / HT29-MTX cells.

In 2019, the REACH-registration dossier of ZnO was evaluated by the European Chemicals Agency (ECHA), which requested additional data on the fate and effects of all nanoforms present on the EU market. A testing scheme was specified, divided into two steps. First, fate data (OECD GD 29; OECD TG 318) were required for the 28 ZnO nanoforms available on the EU market at that time. In the second step, representative nanoforms were tested for their chronic toxicity to aquatic organisms using the freshwater algal growth inhibition test (OECD TG 201) and the Daphnia magna reproduction test (OECD TG 211), applying nano-specific adaptations available before OECD GD 317 was published. The objective of the testing program was to generate robust, GLP-compliant ecotoxicological data to determine whether Zn ions are the primary toxicity driver for nano ZnO or whether specific nano-related effects occur. Results indicated that in all test systems the main fraction consisted of particles and agglomerates with a hydrodynamic diameter&#xa0;>&#xa0;200&#xa0;nm, while only small amounts of dispersed (<200&#xa0;nm) or dissolved (<200&#xa0;nm&#xa0;+&#xa0;3&#xa0;kDa) fractions were detected of which approx. 1.6% to 2.9% were assumed to be nano. Despite particle-algae hetero-agglomeration, effective concentrations from both test systems showed good comparability between ZnO nanoforms and ionic ZnCl2, when considering natural variability within the test. Thus, findings point to ionic zinc as the main driver of toxicity, with no clear evidence for an additional nano-specific effect. Furthermore, sequential filtration measurements provided useful insights into the behaviour of ZnO nanomaterials during testing and their interactions with aquatic organisms.

Microplastics and Nanoplastics (MPs/NPs), as emerging environmental pollutants, are characterized by their resistance to degradation, high mobility, and strong adsorption capacity. They are widely distributed across global environments and enter the human body through multiple pathways, where they interfere with metabolic health. This review introduces the concept of "metabolic footprint" to systematically analyze the environmental behavior of MPs/NPs, human exposure routes, and the associations between MPs/NPs, metabolic pathways, and metabolic diseases. MPs/NPs can induce energy metabolism disorders, insulin resistance, and chronic inflammation through mechanisms including mitochondrial dysfunction, disruption of gut microbiota balance, and interference with hepatic lipid metabolism, thereby increasing the risk of metabolic diseases such as obesity, type 2 diabetes, metabolic dysfunction-associated fatty liver disease, and atherosclerosis. In addition, MPs/NPs of different particle sizes exert distinct pathological effects through size-dependent mechanisms. Furthermore, as carriers of environmental pollutants, MPs/NPs can produce synergistic toxicity. There is an urgent need to establish comprehensive monitoring systems for MPs/NPs, develop effective intervention strategies, and conduct in-depth studies on their long-term health impacts, thereby providing a scientific basis for the formulation of relevant public health policies.