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.

Investigation of toxicological profile and possible side effects of engineered nanomaterials (ENMs) is of high importance. Historically, two-dimensional (2D) cell culture was used to study the toxicity of the ENMs, but due to their inability to simulate in vivo cell behavior, three-dimensional (3D) cell culture systems have been developed. Nanotoxicity studies initiate with in vitro experiments and continue with in vivo studies, which are very challenging and sometimes accompanied by conflicting data due to the in vitro-in vivo gap. Thus, scientists are turning their attention to microfabrication techniques and engineered systems "called organ-on-a-chips", which act as an intermediate between in vivo and in vitro systems. The present account tries to review the classical study models and suitably cover the emerging 3D culture models including scaffold-free and scaffold-based 3D cell cultures, 3D co-culture with direct contact and without cell-cell contact methods as well as microfluidic-based tissue chips and organoids. Overall, this review aims to give readers a better insight about the ENMs' toxicology and fill the gaps between the knowledge and practical techniques. Hopefully, the presented information will resolve the issues of 2D in vitro cultures and display the clinically relevant responses to the concerns of therapeutic ENMs.

Inhalation is a primary route of exposure to engineered nanomaterials (ENMs), enabling particles to penetrate deeply into the lungs and subsequently leading to adverse health effects. Human health risk assessment addresses the potential risk posed by ENMs. The aim was achieved by measuring the emissions of ENMs using real-time instrumentation and subsequently applying the data to evaluate associated human health risks using ModelRisk. Emissions during the synthesis of silver nanoparticles (AgNPs), gold nanoparticles (AuNPs), graphene 2D (G2D) nanomaterials, multiwalled carbon nanotubes (MWCNT) and the application of AuNPs on black carbon electrodes were monitored using a NanoScan SMPS Model 3910 and Optical Particle Sizer (OPS) Spectrometer Model 3330. The derived mass-based time-weighted average concentrations were reported for AgNPs and MWCNTs in comparison with occupational exposure limits (OELs). AgNP concentrations of 0.36 µg/m3 and 3.99 µg/m3 for the NanoScan SMPS and OPS, respectively, exceeded the OEL of 0.19 µg/m3, whereas MWCNT concentrations (0.261 µg/m3) remained below the OEL of 1 µg/m3. AuNP synthesis resulted in particle number concentrations exceeding the provisional nano reference value of 20,000 particles/cm3 for the OPS data (3.74 × 104 particles/cm3), whereas application of AuNPs on carbon black electrodes was below this limit. Although no OEL exists for graphene, risk estimates indicated potential adverse health effects like those observed for AgNPs, AuNPs, and MWCNTs. Measured exposure concentrations were applied in a human health risk assessment model, highlighting ENM concentration as a key determinant of risk. These findings emphasise the need for continuous monitoring, further risk assessment studies, and proactive risk management strategies.

Combined effects of nanomaterials and climate change on aquatic ecosystems: Toxicity, interactions, and regulatory challenges.

Heavy metals, plastic-derived chemicals, and pharmaceuticals remain toxic, harming humans and the environment. Traditional methods for removing pollutants are effective but tedious and not fully successful, and prominent alternative techniques are essential. Several investigations revealed that engineered nanomaterials, plants, and their derived phytochemicals control the fate of emerging contaminants by altering their properties (physical and chemical). Therefore, combining these methods could produce a tool for removing the contaminants. Phytocompounds like alkaloids, terpenoids, and tannins chelate, absorb, and detoxify the contaminants. This gives out phytochemicals that result in the synthesis of engineered nanomaterials (ENMs) through an eco-friendly way acting as stabilizers capping agents together with reducing agents hence producing a safer nanoformulation which in turn eases elimination of pollutants. In addition to the polymer, carbon nanomaterials, and metal oxide nanoparticles provide larger surface areas with catalytic, adsorptive, and degradable surfaces that can trap pollutants. Thus, plant-derived products mixed with ENMs will create a synergistic effect that increases the reactivity of nano-formulations and their capacities toward clearing environmental contaminants from soils, sediments, and water. Thus, knowledge about ENMs interactive behavior with plant-associated chemicals is crucial for synthesizing a potential bio-nano remediation method. The current paper provides an in-depth discussion of the combined mechanisms of medicinal plant compounds and nanomaterials that could facilitate pollution impact assessments in a sustainable, nature-based manner.

The global agricultural sector faces an unprecedented crisis characterized by stagnant crop yields, diminishing nutrient use efficiency (NUE), and ecological degradation caused by the over-application of conventional agrochemicals. To address these challenges, "Nano-agronomy" has emerged as a transformative discipline, offering precision-based solutions through the integration of engineered nanomaterials (ENMs). This review provides a comprehensive analysis of the molecular and physiological mechanisms governing the interaction between nanomaterials and plant systems. We examine the physicochemical properties of nanoparticles—such as surface-to-volume ratio, morphology, and zeta potential—and how these factors influence the "nano-bio" interface at both the soil and foliar levels. A critical focus is placed on the mechanistic pathways of uptake, including apoplastic and symplastic transport, and the systemic translocation of nanoparticles through the xylem-phloem vascular network. The review evaluates the deployment of stimuli-responsive nano-fertilizers and nano-pesticides that leverage pH, enzymatic, or moisture-triggered release to minimize environmental runoff and maximize bioavailability. Furthermore, we explore the cutting-edge integration of nanosensors and "Internet of Plants" (IoP) technologies for real-time monitoring of abiotic and biotic stresses. While nanotechnology offers a path toward a "Second Green Revolution" by enhancing photosynthetic efficiency and stress resilience, we also address the critical bottlenecks of phytotoxicity, trophic transfer risks, and the long-term impact on the soil microbiome. To ensure a balanced overview, it is essential to note that while these technologies show transformative potential, they are accompanied by significant limitations. Concerns regarding environmental persistence, bioaccumulation in edible tissues, and the disruption of beneficial mycorrhizal networks must be mitigated through "Safety-by-Design" strategies. Additionally, the field faces regulatory hurdles due to fragmented frameworks that often fail to account for nanomaterial transformations within complex agroecosystems. Addressing these ecological and regulatory challenges is indispensable for the responsible and sustainable integration of nanotechnology into global food systems.

Ethiopian agriculture is challenged by low soil fertility, erratic rainfall, and limited nutrient use efficiency of conventional fertilizers. A more innovative fertilization strategy is needed to enhance productivity while remaining environmentally sustainable. This article reviews recent advancements in nano fertilizers (NFs) and highlights their potential benefits for Ethiopian smallholder and commercial farming systems. Nano fertilizers can significantly contribute to sustainable farming in both field and greenhouse environments by improving nutrient use efficiency (NUE), particularly for staple crops like teff, maize, wheat, sorghum, and pulses. Unlike conventional synthetic fertilizers, which typically release nutrients rapidly within 4–10 days, NFs can provide a slow and steady nutrient supply over 40–50 days, either alone or in combination with organic amendments or inorganic inputs. In addition to enhancing nutrient availability, NFs strengthen crop tolerance to drought, heat, and soil stressors common across Ethiopian agro ecologies. Their precise nutrient delivery minimizes environmental losses, enhances crop growth, and reduces the ecological footprint of agricultural inputs. Engineered nanomaterials (ENMs) present opportunities to replace or reduce conventional fertilizers and pesticides, thereby decreasing soil and water contamination. Controlled release or slow-release nano nitrogen fertilizers, in particular, have shown promising results in improving yields while reducing agro?environmental constraints in Ethiopian contexts. Nano fertilizers - whether applied to the soil or foliage - represent one of the most promising engineered materials for future Ethiopian agriculture. This article highlights the potential of nano-enabled fertilizers (n NFs) as an innovative approach to improving NUE and reducing nutrient losses, thereby supporting sustainable agricultural intensification. It examines synthesis, mode of action, and various types of nano fertilizers, including those formulated with nanoparticles of essential macro- and micronutrients (such as N, P, K, Fe, and Mn). In these formulations, nutrients are either individually bonded or combined with nano-dimensional carriers to ensure regulated and efficient delivery to the plant rhizosphere.

Food science has seen a revolution because of nanotechnology, which uses materials at the nanoscale to improve quality, safety, and usefulness. With sizes ranging from 1 to 100 nm, nanoparticles (NPs) have special physical and chemical characteristics that set them apart from their bulk counterparts. These substances are used in packaging for antibacterial and preservation reasons, as well as in food systems to enhance texture, stability, colour, and nutrition delivery. However, there are serious safety and toxicological issues, frame work and risk Factors with the increasing use of engineered nanomaterials (ENMs) in food and feed items. Both inorganic (like silver, titanium dioxide, iron oxide, and zinc oxide) and organic (like lipid, protein, and carbohydrate- based nanoparticles) food-related nanoparticles are classified in this review, along with their fate and possible toxicity in the gastrointestinal tract (GIT). Organic nanoparticles are often less harmful because of enzymatic breakdown, whereas inorganic nanoparticles have demonstrated variable levels of accumulation and organ toxicity based on size, solubility, and reactivity. Limited and contradictory toxicological data highlight the urgent need for thorough long-term studies on nanoparticle exposure through diet, medicines, despite promised functional improvements. The fast-developing nano-enabled food technology and feed, it is crucial to comprehend the risk factors, the nanoparticles interact with biological systems in order to create appropriate regulatory frameworks and guarantee consumer safety.

Agroecosystems, which sustain global food production and economic stability, face increasing threats from emerging contaminants such as microplastics, Per- and polyfluoroalkyl substances (PFAS), pharmaceuticals, and engineered nanomaterials (ENMs). These pollutants persist in the environment, bioaccumulate in crops, and impose complex risks to soil health, biodiversity, and human well-being. Microplastics derived from agricultural plastics and sewage sludge disrupt soil structure and microbial communities, while PFAS migrate into groundwater and contaminate drinking water supplies. Pharmaceuticals introduced through wastewater irrigation and manure application accelerate antimicrobial resistance, and ENMs used in agrochemicals influence nutrient dynamics and soil chemistry. Despite growing recognition of these hazards, regulatory responses remain fragmented and current risk-assessment frameworks insufficient. This review synthesizes advanced detection tools-including CRISPR-based biosensors, machine-learning contamination mapping, and high-resolution spectroscopy-with sustainable remediation strategies such as phytoremediation, biochar amendments, and nano-enabled pollutant degradation. By comparing emerging contaminants with conventional pollutants, this work establishes their unique persistence, mobility, and policy challenges while linking their impacts to Sustainable Development Goals (SDGs) 2, 3, and 6. Importantly, the review emphasizes that long-term resilience of agroecosystems requires coordinated global policy alignment, integration of interdisciplinary monitoring systems, and stakeholder engagement to reduce contaminant loads. Future research should prioritize harmonized toxicity thresholds, long-term field experiments on contaminant-crop interactions, and scalable, low-cost detection platforms suitable for resource-limited regions. Together, these efforts will be essential for mitigating EC-related risks, strengthening food security, and safeguarding environmental and public health.

Metallic engineered nanomaterials (ENMs) have enormous technological potential and are increasingly applied across different fields and products. However, substances (including ENMs) can be detrimental to the environment and human health, thus requiring systematic testing to uncover potential hazardous effects (in compliance with REACH). Although hazard testing traditionally involves the use of animal experiments, recent years have seen a shift towards in silico modeling. High-quality data is required for in silico modeling, which is frequently not readily available for ENMs. Vast amounts of data have been published in literature but they are unstructured and scattered across numerous sources. To mitigate the limitations in data availability, we have compiled and created a nanotoxicity dataset based on published literature. The compiled dataset focuses mainly on acute in vivo endpoints conducted in a laboratory setting using metallic nanomaterials. The data extracted from literature include material information, physico-chemical properties, experimental conditions, endpoint information, and literary meta-data. The dataset presented here is useful for meta-analysis or in silico modeling purposes.

Evaluation of sources of variability in a nitric oxide screening assay for engineered nanomaterials.

Species traits differ between organisms and result in variable sensitivity towards contaminants. Body size is regarded as a "master trait" as it correlates and scales with several internal processes within organisms such as their metabolic rate. Smaller-sized species typically have higher metabolic and uptake rates and thus tend to be more sensitive to contaminants. While the correlation between body size and toxicity has been investigated previously, this is in its infancy for engineered nanomaterials (ENMs). This study investigates size-dependent scaling relationships between different species groups and the toxicity of metallic ENMs. Nano-QSARs were used to generate data that mimic controlled laboratory experiments, which are subsequently fitted to statistical models. Results indicated that the toxicity of ENMs scales linearly with body size, whereby smaller-sized species (crustaceans and phytoplankton) were generally more sensitive. Size-dependent scaling relationships have the potential to enable informed extrapolation across species when toxicity data are limited. This can assist in prioritizing the generation of experimental data, potentially reducing the necessity for further animal testing.

The growing complexity of wastewater pollution caused by rapid industrialization, urbanization, and emerging contaminants has exposed the limitations of conventional treatment technologies. This review explores the transformative role of engineered nanomaterials (ENMs) in addressing these challenges through advanced adsorption, photocatalysis, and disinfection mechanisms. Various nanomaterials—including carbon nanotubes, titanium dioxide, metal oxides, nano-clays, and hybrid nanocomposites—have demonstrated significant potential in removing heavy metals, dyes, pesticides, and microbial contaminants from wastewater. The study also discusses green synthesis approaches that promote environmentally benign nanomaterial production and the integration of nanotechnology with biological systems for enhanced pollutant degradation. Such nano-bioremediation techniques leverage the synergistic effects of nanoparticles and microorganisms to achieve higher treatment efficiency and resource recovery. However, despite their promising capabilities, concerns regarding nanotoxicity, bioaccumulation, and environmental persistence pose critical challenges to large-scale implementation. The paper underscores the need for standardized assessment frameworks, sustainable synthesis strategies, and risk mitigation measures to ensure that nanotechnology advances wastewater remediation without compromising ecological and human health.

The rapid advancement and integration of engineered nanomaterials (ENMs) into consumer products, industrial processes, biomedical applications, and environmental technologies have revolutionized multiple sectors. However, their increased production and environmental release raise critical concerns about unintended interactions with microbial ecosystems. ENMs, including metal-based nanoparticles (silver, titanium dioxide, zinc oxide) and carbon nanomaterials (graphene, carbon nanotubes), possess unique physicochemical properties such as high surface area-to-volume ratios, tunable reactivity, and antimicrobial potential that allow them to interact directly with microbial cells or indirectly influence their habitats. This review critically examines the emerging evidence on ENM–microbiome interactions across human, aquatic, terrestrial, and agricultural systems. In human-associated microbiomes, especially the gut, ENMs can induce dysbiosis by disrupting microbial diversity, altering metabolite production (e.g., short-chain fatty acids), and impairing gut barrier integrity, contributing to inflammation and metabolic disorders. In environmental settings, ENMs influence key microbial functions like nitrogen fixation, organic matter decomposition, and biogeochemical cycling, potentially undermining ecosystem stability and agricultural productivity. Moreover, ENMs are increasingly implicated in accelerating antimicrobial resistance by promoting horizontal gene transfer and enriching resistance genes in microbial communities. The review highlights methodological advances such as high-throughput sequencing, meta-omics approaches, in vitro colon simulators, and in vivo models that have enhanced the assessment of ENM-induced microbiome alterations. Despite these advances, significant gaps remain in understanding long-term and low-dose effects, dose–response relationships, and ecological thresholds. Addressing these gaps through multidisciplinary research and regulatory frameworks is essential for ensuring the safe and sustainable deployment of nanotechnologies in a microbiome-sensitive world.

Integrating engineered nanomaterials into sustainable plant disease management: Evaluating efficacy, driving factors, and mechanistic understandings.

Generating appropriate ecological risk assessments to support the rapid growth of nanotechnology requires a comprehensive understanding of the potential effects of engineered nanomaterials (ENMs), both toxic and beneficial, and accurate predictions of their environmental concentrations. While significant data exists for widely used nanomaterials, there remains a critical knowledge gap regarding the environmental and biological impacts of emerging ENMs, including graphene oxide, nanodiamonds, carbon nanotubes, and less common metal and metal oxides. This review aims to synthesize current knowledge on the ecological risks of emerging ENMs in aquatic environments. The concentrations are likely to be below common toxicological endpoints. In addition, for some of them there is the potential for hormesis: a beneficial dose that promotes growth of the organisms. Novel approaches, such as the "omics," can elucidate these effects. The review identifies key knowledge gaps, such as the necessity for better information on the effects of nanomaterial mixtures and the potential effects of organisms on the fate of ENMs, as well as for better models for estimating biomagnification. While the integration of artificial intelligence will serve to close these knowledge gaps, more standardized toxicity testing protocols are required to expand the number of studies that can be used to train machine learning models.

Engineered nanomaterials (ENMs) exhibit novel properties that offer significant benefits across various industrial sectors and are increasingly present in consumer products worldwide. However, safety assessments have predominantly focused on specific regions, such as the European Union (EU), leaving potential human and environmental risks in other areas insufficiently understood. The absence of a globally harmonized regulatory framework further complicates risk management, due to data variability, uncertainty, and the complexity of ENMs. In response, some countries have developed diverse tools and methodologies to address these regulatory challenges. This article presents an overview of current safety assessment methodologies and reviews international regulatory approaches for ENMs. It also proposes general recommendations for initiating a regulatory framework in Mexico, informed by existing scholarly insights. The aim is to support the development of locally relevant strategies that align with international best practices.

The proliferating incorporation of engineered nanomaterials (ENMs) in everyday consumer products, such as sunscreen, poses concerns about the dermal exposure effects of these ENMs. Well-characterized ENMs, titanium dioxide and zinc oxide, are utilized as models to understand ENM interactions with skin cells and their influence on wound closure. The ENMs, at relevant exposure doses, have been demonstrated to promote the wound closure process in both in vitro and ex vivo skin explant models. Mechanistic studies reveal that the wound closure process is modulated by intracellular ROS production, with the involvement of autophagy, JNK, and ERK signaling pathways, to promote ENM-induced focal adhesion turnover, microtubule remodeling, and cell migration.

Quercetin-conjugated gold-decorated simonkolleite nanohybrids: Insights into oxidative stress and antibacterial activity.

Amyloid-β (Aβ) fibrillation is a spontaneous, thermodynamic process governed by nucleation and elongation. While many studies have explored the ability of engineered nanomaterials (ENMs) to modulate Aβ fibrillation, such as inhibitors, promoters, and dual-modulators, the key physicochemical property of ENMs that determines this behavior remains unclear. In this study, we developed a comprehensive library of ENMs with well-controlled physicochemical properties, including surface charges, morphologies, and hydrophilicity, to systematically investigate their effects on Aβ40 fibrillation. We identified hydrophilicity as the primary determinant of ENM-mediated modulation, rather than surface charge or morphology. Thioflavin T (ThT) kinetics assays indicated that hydrophilic ENMs exhibited bidirectional modulation, both promoting and inhibiting fibrillation depending on concentration. This bidirectional effect results from a competition between accelerated nucleation and decelerated elongation. While hydrophobic ENMs exhibited only unidirectional inhibition from the initial nucleation phase, two-dimensional-NMR (2D-NMR) mechanism studies indicated that this difference resulted from specific interactions with Aβ40 residues. Hydrophilic ENMs targeted hydrophilic residues involved in elongation, including Arginine R5, Glycine G9, G25, G33, G37, and G38, Lysine K28, and Alanine A30, while hydrophobic ENMs bound to hydrophobic residues critical for nucleation, such as I31. These findings provide mechanistic insight into NP-peptide interactions and lay a foundation for the rational design of nanomaterials to modulate amyloid fibrillation.