To Örebro University

As the volume of plastic waste from electrical and electronic equipment (WEEE) continues to rise, a significant portion is disposed of in the environment, with only a small fraction being recycled. Both disposal and recycling pose unknown health risks that require immediate attention. Existing knowledge of WEEE plastic toxicity is limited and mostly relies on epidemiological data and association studies, with few insights into the underlying toxicity mechanisms. Therefore, this study aimed to perform comprehensive chemical screening and mechanistic toxicological assessment of WEEE plastic-associated chemicals. Chemical analysis, utilizing suspect screening based on high-resolution mass spectrometry, along with quantitative target chemical analysis, unveiled numerous hazardous compounds including polyaromatic compounds, organophosphate flame retardants, phthalates, benzotriazoles, etc. Toxicity endpoints included perturbation of morphological phenotypes using the Cell Painting approach, inflammatory response, oxidative stress, and endocrine disruption. Results demonstrated that WEEE plastic chemicals altered the phenotypes of the cytoskeleton, endoplasmic reticulum, and mitochondria in a dose-dependent manner. In addition, WEEE chemicals induced inflammatory responses in resting macrophages and altered inflammatory responses in lipopolysaccharide-primed macrophages. Furthermore, WEEE chemicals activated the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, indicating oxidative stress, and the aryl hydrocarbon receptor (AhR). Endocrine disruption was also observed through the activation of estrogenic receptor-α (ER-α) and the induction of anti-androgenic activity. The findings show that WEEE plastic-associated chemicals exert effects in multiple subcellular sites, via different receptors and mechanisms. Thus, an integrated approach employing both chemical and toxicological methods is essential for comprehensive assessment of the toxicity mechanisms and cumulative chemical burden of WEEE plastic-associated chemicals.

Existing research has proven difficult to understand the interplay between upstream signalinge vents during NLRP3 inflammasome activation. Additionally, events downstream of inflammasome complex formation such as cytokine release and pyroptosis can exhibit variation, further complicating matters. Cell Painting has emerged as a prominent tool for unbiased evaluation of the effect of perturbations on cell morphological phenotypes. Using this technique, phenotypic fingerprints can be generated that reveal connections between phenotypes and possible modes of action. To the best of our knowledge, this was the first study that utilized Cell Painting on human THP-1 macrophages to generate phenotypic fingerprints in response to different endogenous and exogenous NLRP3 inflammasome triggers, and to identify phenotypic features specific to NLRP3 inflammasome complex formation. Our results demonstrated that not only can Cell Painting generate morphological fingerprints that are NLRP3 trigger-specific, but it can identify cellular fingerprints associated with NLRP3 inflammasome activation.

The innate immune system is the first player involved in the recognition/interaction with nanomaterials. Still, it is not the only system involved. The co-evolution of the microbiota with the innate immune system built an interdependence regulating immune homeostasis that is poorly studied. Herein, the simultaneous interaction of iron-oxide nanoparticles (Fe-oxide NPs), immune cells, and the microbiota associated with the blood of the sea urchin Paracentrotus lividus was explored by using a microbiota/immune cell model in vitro-ex vivo and a battery of complementary tools, including Raman spectroscopy, 16S Next-Generation Sequencing, high-content imaging, NanoString nCounter. Our findings highlight the P. lividus immune cells and microbiota dynamics in response to Fe-oxide NPs, including i) morphological rearrangement and immune cell health status maintenance (intracellular trafficking increasing, no phenotypic alterations or caspase 3/7 activation), ii) transcriptomic reprogramming in immune cells (Smad6, Lmo2, Univin, suPaxB, Frizzled-7, Fgfr2, Gp96 upregulation), iii) immune signaling unchanged (e.g., P-p38 MAPK, P-ERK, TLR4, IL-6 protein level unchanged), iv) enrichment in extracellular vesicle released in the co-culture medium, and v) a shift in the composition of microbial groups mainly in favor of Gram-positive bacteria (e.g., Firmicutes, Actinobacteria),. Our findings suggest that Fe-oxide NPs induce a multilevel immune cell-microbiota response restoring homeostasis.

Chromium (cr) toxicity, even at low concentrations, poses a significant health threat to various environmental species. Cr is found in the environment in two oxidation states that differ in their bioavailability and toxicity. While cr(iii) is essential for glucose metabolism, the oxyanion chromate cr(vi) is mostly of anthropogenic origin, toxic, and carcinogenic. The sources of cr in the environment are multiple, including geochemical processes, disposal of industrial waste, and industrial wastewater. Cr pollution may consequently impact the health of numerous plant and animal species. Despite that, the number of published studies on cr toxicity across environmental species remained mainly unchanged over the past two decades. The presence of cr in the environment affects several plant physiological processes, including germination or photosynthesis, and consequently impacts growth, and lowers agricultural production and quality. Recent research has also reported the toxic effects of cr in different aquatic and terrestrial organisms. whereas some species showed sensitivity, others exhibited tolerance. Hence, this review discusses the understanding of the ecotoxicological effect of cr on different plant and animal groups and serves as a concise source of consolidated information and a valuable reference for researchers and policymakers in an understanding of cr toxicity. Future directions should focus on expanding research efforts to understand the mechanisms underlying species-specific responses to cr pollution.

Metal additive manufacturing (AM) is gaining traction but raises worker health concerns due to micron-sized powders, including fine inhalable particles. This study explored particle and surface characteristics, electrochemical properties, metal release in artificial lysosomal fluid (ALF), and potential toxicity of virgin and sieved virgin Fe-based powders, stainless steel (316L), Fe, and two tooling steels. Virgin particles ranged in size from 1 to 100μm, while sieved particles were within the respirable size range (<5–10μm). Surface oxide composition differed from bulk composition. The Fe powder showed low corrosion resistance and high metal release due to a lack of protective surface oxide. Sieved particles of 316L, Fe, and one tooling steel released more metals into ALF than virgin particles, with the opposite was observed for the other tooling steel. Sieved particles had no notable impact on cell viability or micronuclei formation in human bronchial epithelial cells. Inflammatory response in human macrophages was generally low, except for the Fe powder and one tooling steel, which induced increased interleukin-8 (IL-8/CXCL-8) and monocyte chemoattractant protein-1 (MCP-1/CCL-2) secretion. This study underscores distinctions between virgin and sieved Fe-based powders and suggests relatively low acute toxicity.

Tire wear particles (TWP) stand out as a major contributor to microplastic pollution, yet their environmental impact remains inadequately understood. This study delves into the cocktail effects of TWP leachates, employing molecular, cellular, and organismal assessments on diverse biological models. Extracted in artificial seawater and analyzed for metals and organic compounds, TWP leachates revealed the presence of polyaromatic hydrocarbons and 4-tert-octylphenol. Exposure to TWP leachates (1.5 to 1000 mg peq L-1) inhibited algae growth and induced zebrafish embryotoxicity, pigment alterations, and behavioral changes. Cell painting uncovered pro-apoptotic changes, while mechanism-specific gene-reporter assays highlighted endocrine-disrupting potential, particularly antiandrogenic effects. Although heavy metals like zinc have been suggested as major players in TWP leachate toxicity, this study emphasizes water-leachable organic compounds as the primary causative agents of observed acute toxicity. The findings underscore the need to reduce TWP pollution in aquatic systems and enhance regulations governing highly toxic tire additives.

This study presents a comprehensive chemical and toxicological screening of chemicals extracted from WEEE (waste from electrical and electronic equipment) plastics. Chemical identification was conducted through suspect and target screening methods, revealing a diverse array of hazardous compounds including polycyclic aromatic compounds (PACs), organophosphate flame retardants (OPFRs), phthalates, benzotriazoles, and others. Toxicological endpoints included cell morphological phenotypes, inflammatory response, aryl hydrocarbon receptor (AhR) activation, activation of estrogenic receptor, and anti-androgenic activity. Results demonstrated that WEEE plastic chemicals significantly altered cell morphological phenotypes, particularly affecting the cytoskeleton, endoplasmic reticulum (ER), and mitochondrial measures. Moreover, WEEE chemicals induced inflammatory responses in resting human macrophages and altered ongoing inflammatory responses in lipopolysaccharide (LPS)-primed macrophages. Furthermore, WEEE chemicals exhibited potent AhR agonistic activity, activated estrogen receptor-α (ERα), and inhibited androgen receptor (AR) activation. The findings suggest that WEEE plastic chemicals exert their effects through multiple modes of action, targeting various subcellular sites. Thus, a combined approach utilizing non-target and target screening tools is essential for comprehensively assessing the toxic effects and health hazards associated with WEEE plastic chemicals.

Due to their exceptional properties and cost effectiveness, polyamides or nylons have emerged as widely used materials, revolutionizing diverse industries, including industrial 3D printing or additive manufacturing (AM). Powder-based AM technologies employ tonnes of polyamide microplastics to produce complex components every year. However, the lack of comprehensive toxicity assessment of particulate polyamides and polyamide-associated chemicals, especially in the light of the global microplastics crisis, calls for urgent action. This study investigated the physicochemical properties of polyamide-12 microplastics used in AM, and assessed a number of toxicity endpoints focusing on inflammation, immunometabolism, genotoxicity, aryl hydrocarbon receptor (AhR) activation, endocrine disruption, and cell morphology. Specifically, microplastics examination by means of field emission scanning electron microscopy revealed that work flow reuse of material created a fraction of smaller particles with an average size of 1-5 µm, a size range readily available for uptake by human cells. Moreover, chemical analysis by means of gas chromatography high-resolution mass spectrometry detected several polyamide-associated chemicals including starting material, plasticizer, thermal stabilizer/antioxidant, and migrating slip additive. Even if polyamide particles and chemicals did not induce an acute inflammatory response, repeated and prolonged exposure of human primary macrophages disclosed a steady increase in the levels of proinflammatory chemokine Interleukin-8 (IL-8/CXCL-8). Moreover, targeted metabolomics disclosed that polyamide particles modulated the kynurenine pathway and some of its key metabolites. The p53-responsive luciferase reporter gene assay showed that particles per se were able to activate p53, being indicative of a genotoxic stress. Polyamide-associated chemicals triggered moderate activation of AhR and elicited anti-androgenic activity. Finally, a high-throughput and non-targeted morphological profiling by Cell Painting assay outlined major sites of bioactivity of polyamide-associated chemicals and indicated putative mechanisms of toxicity in the cells. These findings reveal that the increasing use of polyamide microplastics may pose a potential health risk for the exposed individuals, and it merits more attention.

PFAS are ubiquitous industrial chemicals with known adverse health effects, particularly on the liver. The liver, being a vital metabolic organ, is susceptible to PFAS-induced metabolic dysregulation, leading to conditions such as hepatotoxicity and metabolic disturbances. In this study, we investigated the phenotypic and metabolic responses of PFAS exposure using two hepatocyte models, HepG2 (male cell line) and HepaRG (female cell line), aiming to define phenotypic alterations, and metabolic disturbances at the metabolite and pathway levels. The PFAS mixture composition was selected based on epidemiological data, covering a broad concentration spectrum observed in diverse human populations. Phenotypic profiling by Cell Painting assay disclosed predominant effects of PFAS exposure on mitochondrial structure and function in both cell models as well as effects on F-actin, Golgi apparatus, and plasma membrane-associated measures. We employed comprehensive metabolic characterization using liquid chromatography combined with high-resolution mass spectrometry (LC-HRMS). We observed dose-dependent changes in the metabolic profiles, particularly in lipid, steroid, amino acid and sugar and carbohydrate metabolism in both cells as well as in cell media, with HepaRG cell line showing a stronger metabolic response. In cells, most of the bile acids, acylcarnitines and free fatty acids showed downregulation, while medium-chain fatty acids and carnosine were upregulated, while the cell media showed different response especially in relation to the bile acids in HepaRG cell media. Importantly, we observed also nonmonotonic response for several phenotypic features and metabolites. On the pathway level, PFAS exposure was also associated with pathways indicating oxidative stress and inflammatory responses. Taken together, our findings on PFAS-induced phenotypic and metabolic disruptions in hepatocytes shed light on potential mechanisms contributing to the broader comprehension of PFAS-related health risks.