Ecotoxicological effects of microplastics on biota: a review

Microplastic contamination in wild freshwater fish: Global trends, challenges and perspectives

Microplastics (MPs) are emerging contaminants of global concern with potential risks to wildlife and human health. This study reviewed the literature on MP contamination in wild freshwater fish, analyzing 144 articles published since 2016. Studies were conducted in 45 countries, mainly by China (8.97 %), Bangladesh and India (8.28 % each), and Indonesia (6.90 %). Cypriniformes were the most studied order (52.08 %), with rivers being the predominant sampling sites (57.64 %). Omnivorous fish (80.55 %) were the most studied, and MPs were found in the gastrointestinal tract (51.10 %), gills (19.38 %), and muscle (10.57 %). A total of 450 fish species were found to be contaminated by MPs, including 35 listed on the IUCN Red List: 2 critically endangered, 8 endangered, 12 vulnerable, and 13 near threatened. Although the representativeness of the data may be compromised by selective sampling, polymers such as PE and PP predominated, typically in the form of blue fibers ranging from 0.1 to 0.5 mm, indicating recurring contamination patterns in freshwater environments. Significant research gaps remain, including the need for standardized methods, broader inclusion of Neotropical fish species, investigation of biological responses, and studies on trophic transfer and biomagnification.

Adsorption kinetics of different mercury species on three kinds of micro-/nano-plastics in micro-polluted aquatic environments and their combined toxicity

The contamination of micro-plastics (MPs)/nano-plastics (NPs) in environment poses a global concern, necessitating a scientific evaluation of their potential risks to ecosystems and organisms. We herein investigated the adsorption kinetics of different mercury species including inorganic mercury (Hg2+), methylmercury (MeHg) and ethylmercury (EtHg) on three different MPs, such as polyethylene MPs (PE MPs), polypropylene MPs (PP MPs) and polystyrene MPs (PS MPs) in micro-polluted water in detail, and further evaluated the individual and combined cytotoxicity of polystyrene NPs (PS NPs)/polypropylene NPs (PP NPs) and different mercury species. The results indicated that EtHg undergoes demethylation partly to form Hg2+ during the adsorption process on PP MPs, and the adsorption kinetics of Hg2+, MeHg and EtHg on three MPs fitted with pseudo-first-order (PFO) model in initial stage and simultaneously fitted with pseudo-second-order (PSO) model during whole adsorption process. This suggested that adsorption of mercury species on three MPs we driven mainly by physical process in initial stage and by chemical process during whole absorption process. In natural micro-polluted water, the equilibrium adsorption capacities (Qe) of Hg2+ on three MPs (156.3-270.3 ng/g) are much higher than that of MeHg (5.562-78.13 ng/g) and EtHg (7.831-70.42 ng/g). Cytotoxicity experiments revealed that PP NPs and PS NPs themselves have little cytotoxicity, but the presence of them can enhance the cytotoxicity of mercury species, showing NPs size-depended and mercury species-depended synergistic toxic effect. The findings of this study provided valuable insights for scientifically evaluating the potential risk of MPs/NPs to ecosystems and organisms.

Microparticles introduced by the processing of traditional Chinese medicine Hirudo nipponica Whitman might pose threat to patients

Hirudo nipponica Whitman (HNW) is a traditional Chinese medicine (TCM) processed from leeches, commonly used for treating blood stasis syndrome, particularly in promoting blood circulation and alleviating blood stasis. This study aimed to examine microparticles (MPs) contamination of leeches and whether the production of MPs was related to processing. The results showed that the abundance of MPs in the whole, sectioned and powdery of HNW was 12.39, 13.93, 35.11 items/g, respectively. Fiber-like particles accounted for 90 % total. Transparent particles were the most abundant, followed by blue and black. Particles <1 mm were the most frequent. Notebly, 100 % cotton was the most detected material in the HNW, while rayon, cellulose and polyester accounted for 46 % of the total. The abundance of particles in powdery HNW increased significantly, with a higher percentage of <1 mm, similar type and colour to whole and sectioned HNW. It suggests that the large MPs may have been cut into smaller MPs during processing and bring more risk of MPs. It alerts us to the fact that pharmaceuticals and even commonly touched food products may pose a greater risk of MPs due to processing.

Presence of microplastics in Sciades herzbergii (Bloch, 1794) captured in harbor areas of the Amazon coast, Maranhão, Brazil

Microplastics (MPs) are plastic particles smaller than 5 mm and are pervasive in numerous marine environments. The aim of the present study was to determine the presence of MPs in the Pemecou sea catfish (Sciades herzbergii) collected in the harbor area of Coqueiros Strait on Maranhão Island in the city of São Luís, state of Maranhão, Brazil. Forty individuals were captured in the rainy and dry seasons. Gastrointestinal tissues were analyzed after digestion in 10 % potassium hydroxide, followed by filtration and analysis by optical microscopy. MPs were detected in 100 % of the individuals, the total amount found was 511 fibers, 353 fragments, and 12 pellets. The most prevalent concentrations were found in adult females, who had an average of 26.63 MPs per individual. These results are relevant for the environmental monitoring of the study area, especially in the context of contamination by MPs in port environments, with possible implications for human health and environmental conservation. ENVIRONMENTAL IMPLICATION: The present work evaluates the environmental quality of a significant port area on the Amazon coast in the State of Maranhão, where Sciades herzbergii specimens were analyzed to assess microplastic contamination levels. The study found substantial quantities of microplastic fibers in all specimens across multiple collection sites, with notable seasonal variations in fiber colors, suggesting diverse sources and dispersion mechanisms. The results indicate that S. herzbergii can serve as a bioindicator of microplastic pollution in the region, providing valuable information for monitoring the impact of marine debris in coastal environments.

Effects of microplastics on hatching success, ingestion, and gut retention in early developmental stages of golden trevally (Gnathanodon speciosus)

Microplastics (MPs) have emerged as a major environmental concern in marine ecosystems, ranking among the most significant contaminants. However, their effects on the early life stages of marine fish remain poorly understood. In this study, we examined the impact of fluorescent low-density polyethylene (LDPE) microspheres on the hatching success, mortality, ingestion, growth, and excretion in eggs, larvae, and juveniles of golden trevally (Gnathanodon speciosus). The results indicated that MP exposure did not significantly affect hatching rates, suggesting a negligible impact at this stage. Similarly, larval growth was not impacted when adequate food (S-type rotifers and copepod nauplii) was available. Despite low ingestion rates, larvae at 10 days post-hatch (dph) and 20 dph exhibited significantly increased mortality at the highest MP concentration (10×, 105 particles m-3), suggesting that factors other than intestinal blockage contributed to these effects. By 60 dph, juveniles were able to excrete ingested microspheres within 4 h. This study provides the first evidence of MP ingestion and its potential risks in the early developmental stages of a coral reef fish species. Our findings offer critical insights into the susceptibility of marine fish larvae and juveniles to MP pollution, emphasizing the need for further research on its ecological consequences.

Genome-wide identification of socs gene in rainbow trout (Oncorhynchus mykiss) and response to microplastic exposure

BACKGROUND

To investigate the response of the suppressor of the cytokine signaling (socs) gene family in rainbow trout following exposure to microplastics, this study conducted a bioinformatics analysis of the socs gene family using rainbow trout genome data, complemented by experiments involving microplastic exposure and gene expression detection.

METHODS AND RESULTS

The findings revealed that the rainbow trout SOCS gene family comprises 27 members, encoding proteins with lengths ranging from 110 to 837 amino acids. Analyses of motifs, domains, and gene structures indicate that members of this family are highly conserved. RNA sequencing data demonstrated that, following microplastic exposure, the expression levels of socs1, socs2, socs3, socs5, socs6, socs7, and cish in the liver, intestine, and brain tissues of rainbow trout underwent significant changes. Additionally, RT-qPCR results indicated that the expression levels of several socs genes were down-regulated, whereas socs1a, socs1b, socs7a1, socs7b1, and socs7b2 exhibited significant up-regulation. These genes may play crucial roles in the response to microplastic exposure in rainbow trout.

CONCLUSION

This study elucidates the involvement of the socs gene family members in the context of microplastic exposure, providing valuable insights into the underlying toxicological mechanisms and enhancing our understanding of the threats posed by plastic pollution to freshwater organisms.

Impact of microplastics exposure on the reconfiguration of viral community structure and disruption of ecological functions in the digestive gland of Mytilus coruscus

Microplastics (MPs) pose ecological risks by serving as viral vectors and disrupting host microbiomes. This study investigated the impact of MPs on the digestive gland virome of Mytilus coruscus through an in situ exposure experiment on Xixuan Island, Zhoushan, China, using polyethylene MPs and metagenomic sequencing. MPs biofilms were dominated by lytic viruses (> 99 %) with low diversity (Shannon index = 4.10 ± 0.39), whereas digestive glands harbored a more diverse virome (Shannon index = 7.26 ± 1.26). MPs ingestion significantly reduced virome diversity and altered viral community composition. Functional analysis showed that MPs biofilms were enriched in genes related to genetic processing, carbohydrate metabolism and membrane biogenesis, while transcription- and replication-related genes declined (P < 0.05) in digestive glands post-ingestion. MPs biofilms carried abundant antibiotic resistance genes (ARGs) and virulence factors, selectively enriching multidrug resistance genes (efrA, patB) while reducing functional viral gene abundance. Metal (Zn, Hg, As) and biocide resistance genes were prevalent in MPs biofilms but declined post-ingestion. Additionally, MPs ingestion weakened microbial network stability, potentially impairing immune regulation and metabolic homeostasis. These findings underscore MPs' role in shaping viral communities and spreading resistance genes, heightening ecological risks in marine environments.

Innovative prototype for the mitigation of water pollution from microplastics to safeguard the environment and health

Microplastics (MPs) are ubiquitary environmental pollutants facilitated by anthropic activities as wastewaters (WWs) not properly treated or dispersed. Our study focused on the validation of an innovative prototype filter for its future applications in WWs Treatment Plants (WWTPs) to reduce the release of MPs in the environment. The aims of the study were: The WWTPs resulted in catching 85 % and 73 % of MPs >10 and MPs <10 μm, respectively; instead, the WWTPs-prototype treated outputs showed a further reduction of 99 % and 92 % of the uncaught MPs. The mussel haemolymphs analysis showed a decrease of 100 % and 95 %, respectively, for both MPs <10 and >10 μm in filtering treatment against the normal WWTPs outputs. We revealed longer LMS times in mussels exposed to prototype-filtered WWs (29-41 min) compared to the raw output of WWTPs (18-24 min). MF and q-PCR of all studied genes revealed a reduced genotoxicity in mussels exposed to prototype-treated WWs. Hence, the results demonstrated the prototype efficacy, and it will be tested in real WWTPs at a field scale in the next study.

Impacts of microplastics on reef-building corals: Disentangling the contribution of the chain scission products released by weathering

Microplastics (MPs) have recently been shown to impact the health of corals negatively. The primary effects are linked to the physical interaction of the particles with coral tissues, such as abrasion that causes wounds. Additionally, MPs can leach contaminants into the seawater, not only the formulation additives but also molecular fragments resulting from the photo-oxidative degradation of the plastic polymer. These contaminants may have further detrimental effects. Currently, the relative contributions of these factors and their potential synergistic actions are not well understood. To address this, we conducted tests on nubbins of the soft coral Pinnigorgia flava and we evaluated the toxicity of reference additive-free MPs (LDPE and PP, sized 125-250 μm) before and after photo-aging, of MPs collected from beaches, and of the corresponding leachates. By FTIR and SEM analysis, we highlighted similarities between photo-aged reference MPs and the beached MPs, both in terms of surface oxidation and structural defects. GC-MS and dissolved organic carbon (DOC) analysis indicated the release of a variety of molecular species from the photo-aged MPs not detected in the pristine counterpart (accounting for 0.6-2.1 % of the original mass), including short-chain poly-oxidized compounds. The exposure of nubbins to the reference MPs highlighted a significant mucus production with PP and LDPE at 1 mg/L. Leachates from the photo-aged PP induced significant polyp retraction at 10 mg/L, while the leachates from photo-aged LDPE induced significant polyp retraction in P.flava at the concentration of 1 mg/L. No significant stress responses were highlighted with the photo-aged MPs and the leachates from pristine MPs. Beached MPs induced significant responses with the lowest observed effect concentration (LOEC) at 0.1 mg/L. This effect was related to the occurrence of plastic additives not detected in the reference MPs. Overall, the results highlighted the importance of considering the contribution of the photo-degradation products released by MPs in ecotoxicological assessments.

Microplastics in marine systems: A review of sources and sinks, typical environmental behaviors, and biological effects

Marine microplastics (MPs), whether originating from household and industrial production or stemming from the degradation of larger plastic fragments, have currently attracted significant global attention among the scientific community. The transport and deposition of MPs, characterized by their small size and large quantity, under oceanic hydrodynamics result in the contamination of a wide range of areas. Furthermore, MPs are capable of carrying metals and organic pollutants that constitute composite pollutants. The additives it carries will gradually release harmful substances during the degradation process. Once ingested by aquatic organisms and amplified by the food chain, these pollutants can adversely affect the survival and growth of marine flora and fauna, ultimately posing potential threats to humans. In this review, the major sources and sinks of MPs are described, considering the pollution of marine ecosystems. Additionally, typical environmental behaviors of MPs including their migration and accumulation in the ocean, their combined ability with heavy metals and organic pollutants, their leaching of additives, and their abiotic and biotic degradation pathways are discussed. The adverse effects on marine organisms resulting from ingestion and translocation of MPs are also reviewed herein. Even though the number of studies on MPs-associated environmental impacts is increasing rapidly, this review underscores that there is a pressing necessity to achieve an integrated assessment of MPs' impacts on marine ecology in order to address existing and future knowledge gaps.

Microplastics in the European native oyster, Ostrea edulis, to monitoring pollution-related patterns in the Solent region (United Kingdom)

Microplastics (MPs) are the most abundant type of debris in the marine environment, creating a significant threat to aquatic ecosystems due to their persistence, ability to absorb organic pollutants and potential ingestion by marine fauna. Shellfish are particularly vulnerable to MPs accumulation as they filter large volumes of seawater, and they become an important route for human exposure to these particles. This study, the first to examine MPs in European flat oyster (Ostrea edulis) populations, aimed to quantify these particles in the gill and digestive tissues of oysters from the Solent region (southern England). Enzymatic digestion using Proteinase-K was used in this study and MPs were identified in every oyster sampled to determine whether differences in abundance, type and size of MPs exist between locations. Oysters near urban areas contained significantly more MPs than those near rural areas. Fibres were the most prevalent type of MPs, with sizes varying across locations. The study found no significant differences in MPs presence between gills and digestive tissues, and an inverse correlation between the size of MPs and oyster size. The presence of MPs in wild O. edulis could be an additional threat to the survival of an already threatened species and may pose health risks for predatory species and human consumers of seafood. The use of O. edulis as a biomonitoring species for marine MPs pollution could help determine the extent, distribution and sources of MPs, potentially informing management strategies to reduce pollution.

Mission Tara Microplastics: a holistic set of protocols and data resources for the field investigation of plastic pollution along the land-sea continuum in Europe

The Tara Microplastics mission was conducted for 7 months to investigate plastic pollution along nine major rivers in Europe-Thames, Elbe, Rhine, Seine, Loire, Garonne, Ebro, Rhone, and Tiber. An extensive suite of sampling protocols was applied at four to five sites on each river along a salinity gradient from the sea and the outer estuary to downstream and upstream of the first heavily populated city. Biophysicochemical parameters including salinity, temperature, irradiance, particulate matter, large and small microplastics (MPs) concentration and composition, prokaryote and microeukaryote richness, and diversity on MPs and in the surrounding waters were routinely measured onboard the French research vessel Tara or from a semi-rigid boat in shallow waters. In addition, macroplastic and microplastic concentrations and composition were determined on river banks and beaches. Finally, cages containing either pristine pieces of plastics in the form of films or granules, and others containing mussels were immersed at each sampling site, 1 month prior to sampling in order to study the metabolic activity of the plastisphere by meta-OMICS and to run toxicity tests and pollutants analyses. Here, we fully described the holistic set of protocols designed for the Mission Tara Microplastics and promoted standard procedures to achieve its ambitious goals: (1) compare traits of plastic pollution among European rivers, (2) provide a baseline of the state of plastic pollution in the Anthropocene, (3) predict their evolution in the frame of the current European initiatives, (4) shed light on the toxicological effects of plastic on aquatic life, (5) model the transport of microplastics from land towards the sea, and (6) investigate the potential impact of pathogen or invasive species rafting on drifting plastics from the land to the sea through riverine systems.

Validating citizen science for community-driven microplastic monitoring and marine protection in Northeast Iceland's Hope Spot

Governments are increasingly monitoring meso- and microplastic (M/MP) pollution in surface waters to develop cost-effective solutions. While citizen science is widely used in programs like the EU's Marine Litter Watch and NOAA's sampling in the U.S., these efforts primarily focus on macro litter, leaving gaps in M/MP data, especially in under-sampled regions like Icelandic waters. This study addresses this gap through a citizen science initiative (2019-2023) that monitored M/MP pollution in the "Northeast Iceland Hope Spot." Fifty-eight trawl samples were collected from whale-watching and expedition vessels using a low-tech aquatic debris instrument (LADI) or a high-speed AVANI trawl. M/MP were present in 86 % of samples, with an average density of 0.02 ± 0.03 particles/m3. Concentrations varied significantly between sites (p = 0.005), peaking in Grímsey (0.070 ± 0.03 particles/m3), followed by Eyjafjörður (0.006 ± 0.04 particles/m3) and Skjálfandi Bay (0.004 ± 0.03 particles/m3). Mesoplastics comprised 44 % and microplastics 56 %, primarily polyethylene (47 %) and polypropylene (39 %)-common materials in fishing gear and household plastics. These findings suggest that local currents and fishing activities influence M/MP distribution. Comparison with previous studies validates the use of the presented citizen science methods for tracking floating M/MP in coastal waters and highlights their value in shaping marine conservation policies, particularly in vulnerable subarctic ecosystems.

Effects of polyamide microplastics with different particle sizes on the development of silkworm Bombyx mori (Lepidoptera: Bombycidae) and its progeny: A study based on the age-stage, two-sex life table

Influenced by human activities, microplastics (MPs) are widely distributed in terrestrial ecosystems. However, their ecotoxicity remains unclear. Therefore, we assessed the ecotoxicity of polyamide microplastics (PA-MPs) by investigating their toxic effects on the model insect, the silkworms Bombyx mori (Lepidoptera: Bombycidae). In this study, fifth-instar silkworm larvae were fed mulberry leaves treated with PA-MPs for 120 hours, but no changes in mortality rates were observed. However, the body weight, pupal weight, cocoon weight, egg laying amount, and cocoon shell weight in F0 generation silkworms were significantly reduced. This indicates that PA-MPs have sublethal effects on silkworms. To further investigate the effects of PA-MPs on the offspring of silkworms, we applied the age-stage, two-sex life table analysis. We found that in the PA-MPs treatment group, the duration of the larval and pupal stages of F1 generation silkworms was significantly prolonged, while the lifespan of the adults and total longevity were shortened. Meanwhile, the life history parameters (sxj, exj, lx, fxj, lxmx, and vxj values) and population parameters (R0, λ, r, and T) of F1 generation silkworms in the PA-MPs treatment group were also lower than control. This indicates that PA-MPs have transgenerational effects, affecting the growth, development, and reproduction of F1 generation silkworms. Our research findings demonstrate the sublethal and transgenerational effects of PA-MPs on silkworms, providing evidence for their ecotoxicity.

Hit the target: A new experimental method to select bioindicators of microplastic ingestion by marine fish

Implementing biomonitoring programs for assessing the impact of microplastic ingestion on marine organisms is a priority to verify the effectiveness of measures adopted by legislative frameworks to deal with plastic pollution. At the European level, the Marine Strategy Framework Directive mandates Member States to establish a unified monitoring approach. However, due to the vast range and differences in marine regions, the selection of bioindicators must be tailored locally. The present study proposes a bioindication score to rapidly assess the aptitude of different species in providing an adequate description of the bioavailability of microplastics. The bioindication score is validated through the analysis of eight fish species from the Central Tyrrhenian Sea, for which a set comprising two pelagic (Scomber colias and Trachurus trachurus) and two benthopelagic/demersal species (Pagellus acarne and Mullus barbatus) is identified as the best group to obtain ecologically relevant data on microplastic ingestion in the study area.

Efficient removal performance of polystyrene microplastics from strongly acidic solutions by two functionalized nanosized biochars derived from low-cost sustainable sources

Microplastic pollution in aquatic systems and other environments has garnered significant concern due to its persistence, widespread environmental migration, and detrimental impact on entire ecosystems. Such pollution type poses severe threats to human life quality, as well as flora and fauna. In response to this pressing global issue, the current research explores a simple, sustainable, and cost-effective solution by employing two newly modified nanobiochar materials with oxalic acid, for the adsorptive removing of polystyrene microplastics (PSMPs) from aquatic systems. The two nanobiochars were derived from sustainable and low-cost feedstocks, specifically pineapple and artichoke wastes via pyrolysis at 300 °C and 350 °C, yielding NBP and NBA, respectively. These were subsequently modified with oxalic acid (OA) to create OA@NBP and OA@NBA nanobiosorbents. The EDX analysis confirmed the primary elemental composition of carbon, oxygen, nitrogen, calcium, and magnesium. TEM analysis revealed distinct differences in particle size and morphology of OA@NBA which displayed small particles ranging from 9.81 to 16.15 nm, while OA@NBP exhibited larger particles with size ranging from 68.86 to 105.12 nm, highlighting their structural differences. OA@NBP and OA@NBA nanobiosorbents were evaluated in PSMPs removing from aquatic systems providing the optimum conditions 30-50 mg nanobiosorbent, 40 min time and pH 2.0. The adsorption and binding mechanisms were best fitted to pseudo-second-order kinetics and Langmuir-Freundlich models. Thermodynamic analysis revealed that the adsorption process was non-spontaneous and endothermic. The loaded PSMPs on OA@NBA and OA@NBP nanobiosorbents were successfully regenerated and successively used to remove PSMPs with 86.8 % and 89.5 %, respectively, after the first regeneration step. Additionally, the two nanobiosorbents demonstrated excellent PSMPs removal efficiencies in simulated seawater samples adjusted to pH 2.0, achieving removal rates of 93.4 % (OA@NBA) and 87.4 % (OA@NBP). Therefore, the characterized PSMPs removal performance at pH 2.0 can afford a good avenue for potential application of the two explored nanobiosorbents in effective removal of PSMPs pollutant from other acidic industrial wastewater matrices.

Microplastic exposure is associated with epigenomic effects in the model organism Pimephales promelas (fathead minnow)

Microplastics have evolutionary and ecological impacts across species, affecting organisms' development, reproduction, and behavior along with contributing to genotoxicity and stress. As plastic pollution is increasing and ubiquitous, gaining a better understanding of organismal responses to microplastics is necessary. Epigenetic processes such as DNA methylation are heritable forms of molecular regulation influenced by environmental conditions. Therefore, determining such epigenetic responses to microplastics will reveal potential chronic consequences of this environmental pollutant. We performed an experiment across two generations of fathead minnows (Pimephales promelas) to elucidate the transgenerational epigenetic effects of microplastic exposure. We exposed the first generation of fish to four different treatments of microplastics: two concentrations of each of pre-consumer polyethylene (PE) and PE collected from Lake Ontario. We then raised the first filial generation with no microplastic exposure. We used enzymatic methylation sequencing on adult liver tissue and homogenized larvae to evaluate DNA methylation differences among treatments, sexes, and generations. Our findings show the origin of the plastic had a larger effect in female minnows whereas the effect of concentration was stronger in the males. We also observed transgenerational effects, highlighting a mechanism in which parents can pass on the effects of microplastic exposure to their offspring. Many of the genes found within differentially methylated regions in our analyses are known to interact with estrogenic chemicals associated with plastic and are related to metabolism. This study highlights the persistent and potentially serious impacts of microplastic pollution on gene regulation in freshwater systems.

Revealing antagonistic interactions in the adverse effects of polystyrene and poly(methyl methacrylate) microplastics in bumblebees

Microplastics pose a significant ecological threat, yet their actual impact on terrestrial ecosystems and organisms remains poorly understood. This study investigates the effects of two common microplastics, poly(methyl methacrylate) (PMMA) and polystyrene (PS), on the pollinator Bombus terrestris, exploring their combined and sublethal effects at three different concentrations (0.5, 5 and 50 mg l-1). PMMA and PS single exposure reduced bee survival in a concentration-dependent manner, whereas combined exposure (MIX) had no significant effect. PS reduced bee sucrose responsiveness, PMMA had no significant effect and MIX enhanced it. Learning and memory tests showed impaired mid-term and early long-term memory in bees exposed to PMMA and PS, with concentration-dependent effects. Interestingly, MIX exposure had no effect on memory retention. Our findings emphasize the differential effects of individual microplastics on bumblebee behaviour, suggesting potential risks to pollinator survival, cognitive function and possibly overall colony health, but also unexpected antagonistic interactions between these pollutants. The PS-PMMA antagonistic interactions highlight a challenge in assessing the toxicity of microplastics. Combined effects may not mirror the individual toxicity of PS and PMMA, highlighting the need for a careful assessment of polymer interactions, especially in environments or organisms contaminated by different microplastics.

Bibliometrics and visualization analysis of microplastics research in water from 2011 to 2023

Microplastics in water have emerged as a significant public concern in recent years due to their potential adverse impacts on both human and animal health. This study conducts an analysis of articles published in key journals indexed in the Web of Science from 2011 to 2023, employing CiteSpace and VOSviewer for data extraction and visualization. The results elucidate a marked increase in both the number of publications and citations since 2018. Initially, the United Kingdom was at the forefront of research output in this domain, with a publication proportion of 16.59% from 2011 to 2017 and 4.37% from 2018 to 2023. However, the proportion of publications in China has increased from 10.31 to 40.45%. Notably, the Marine Pollution Bulletin has not only been an early contributor to this field but also holds the record for the highest number of published articles. Keyword analysis indicates research trends and hotspots. Recent investigations on microplastic removal techniques have predominantly centered on adsorption. Moreover, studies focusing on microplastics in surface water have also garnered considerable attention. This study offers a comprehensive review of existing research and provides guidance for future directions in microplastic research.

Unveiling the duality of cement and concrete addressing microplastic pollution: a review

Microplastic pollution has emerged as a global environmental concern, with diverse consequences for ecosystems and human health. While the focus has primarily been on the sources and impacts of microplastics, this review paper explores the roles of cement and concrete in potentially mitigating microplastic pollution and addressing their negative impacts with the focus of 165 relevant publications. Cementitious materials, widely used in construction, have unique properties that greatly increase the formation and transport of microplastics in the environment, and affect circular economy practice. This paper gathers all the information we already know about how cement, concrete, and microplastics interact with each other. It also presents the potential opportunities and challenges of using these materials to deal with microplastic pollution, entailing the advancement of porous concrete as a filtering system, exploration of concrete wetting phenomena based on concrete's surface chemistry and characteristics, proper urban water management systems for concrete green spaces, assessment of innovative technologies with concrete for microplastic mitigation, and the formation of standards and guidelines such as precise Life Cycle Assessment (LCA) tools, environmental product declaration (EPD), policy for urban planning, and green finance paradigms.

Impact of microplastics on microbial diversity and pathogen distribution in aquaculture ecosystems: A seasonal analysis

Microplastics, as a prominent emerging pollutant in marine environments, pose a serious threat to the stability of marine ecosystems due to their resistance to biodegradation. MPs act as substrates for biofouling and potentially promote the spread of harmful microorganisms. Research indicates that human activities exacerbate MPs pollution in aquaculture environments, significantly increasing their abundance. This study focused on the aquaculture environment of the large yellow croaker (Larimichthys crocea), one of the most extensively farmed fish species in coastal regions. We conducted a comprehensive analysis of microbial diversity on the biofilms covering MPs and in the surrounding aquaculture water, with a focus on the distribution of pathogens on MPs. Furthermore, this study investigated the impact of seasonal variations on the microbial communities within these biofilms. Sequencing analysis revealed that the α-diversity of microbial communities on MPs was lower than that in aquaculture water during winter but higher in summer, indicating a seasonal shift in microbial community structure. PICRUSt predictions suggested that microbes on MPs possess unique metabolic pathways. Co-occurrence network analysis demonstrated that during summer, the microbial communities on MPs revealed increased connectivity and functional modularity, whereas microbial communities in aquaculture water showed stronger interactions in winter. Additionally, several potential pathogens, including Vibrio and Pseudomonas, were detected in the MPs biofilms. These findings underscore the ways in which MPs influence the microbial community structure in aquaculture environments, increasing health risks to the ecosystem. This research offers significant insights into the ecological impacts of MPs pollution on microbial communities in aquaculture ecosystems.

The influence of road vehicle tyre wear on microplastics in a high-traffic university for sustainable transportation

Road-associated microplastics, originating from tire wear and fragmented litter, are significant contributors to microplastic pollution. This study examines the characteristics of these particles within a university, focusing on their size, shape, color, and polymer composition. Suspended microplastics were collected using portable active samplers for PM10 and results have shown that PM10 concentrations peaked on Thursdays and declined, reaching their lowest levels on Sundays, with overall weekend measurements indicating reduced concentrations compared to weekdays. Importantly, the presence of microplastics correlated with increased PM10 levels. These findings highlighted a dominance of irregularly fragmented black microplastics, primarily composed of polyethylene, polypropylene, and polybutadiene, influenced mainly by vehicular movement. Additionally, metal contaminants such as aluminum, iron, and zinc were identified through SEM-EDX analysis of selected microplastics, particularly concentrated at the university's main entrance, the area with the highest traffic. This research enhances understanding of atmospheric microplastic pollution in university environments with heavy vehicle traffic and supports efforts to promote sustainable transportation and climate-friendly initiatives.

Microplastic changes during the development of cervical cancer and its effects on the metabolomic profiles of cancer tissues

Recent studies have detected microplastics (MPs) in reproductive organs and found that they exert toxic effects on the reproductive system. However, the exact mechanism of action remains unclear. This study evaluates changes in MP levels in patients with cervical cancer as the disease progresses and uses untargeted metabolomics to assess the impact of MP exposure on the metabolomic profiles of cervical invasive cancer tissues. A total of 12 MP types were identified in 101 MP particles, with an average abundance of 2.24 ± 1.61 MP particles/g. Of these, polyethylene (PE, 26.73 %) and polypropylene (PP, 19.80 %) were the most frequently detected. Also, some MPs were observed to have sizes smaller than 20 µm. Notably, MP exposure levels increase as cervical cancer progresses (p < 0.05). Metabolomics analysis revealed that, among the 33 biologically significant metabolites screened, D-Mannose and cis,cis-muconic acid showed the most significant differences. Additionally, the aminosugar and nucleotide sugar metabolism pathways were the most significantly enriched in this experiment, potentially acting as pathways through which MPs may contribute to the pathogenesis of cervical cancer. The metabolites and pathways identified in this study may offer new insights and opportunities for disease research in patients with cervical cancer.

Do microplastics dramatically shape the homogeneity of protozoan colonization in marine environments?

The impacts of microplastics (MPs) on the marine ecosystem have remained the focus of global attention. The microbial colonization plays an important role in driving the functional process of entire marine ecosystems, during which protozoa employ primary contributors for transferring the energy flow from the low to high trophic levels. To investigate the effects of MPs on microbial colonization, the protozoan assemblages were used as test organisms and exposed to a gradient of MP concentrations. With the increase of MP stress, the homogeneity of the test organisms was significantly altered: (1) the α- and γ-diversity indices decreased; (2) both univariate β-diversity and multivariate dispersions in species composition with weighted relative abundance increased; and (3) the traditional β-diversity showed a close linear relationship with multivariate dispersions in both the species composition and weighted relative abundance. Therefore, the results suggest that microplastics may dramatically impact the homogeneity of protozoan colonization in marine ecosystems.

Impact of microplastics exposure on liver health: A comprehensive meta-analysis

Microplastics (MPs) are significant concerns affecting liver health. This is the first comprehensive meta-analysis, evaluating the impact of MPs on liver functions across various animal models, including mice, fish, crabs, and shrimp. Five databases, including PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, and Web of Science, were used to select eligible studies. In all, 70 studies out of 1872 publications were included in the analysis, the impact of MPs on liver enzymes, oxidative stress markers, and inflammatory cytokines were evaluated. Our results revealed significant increases in liver enzymes ALT and AST, oxidative stress markers MDA, and pro-inflammatory cytokines IL-6 and TNF-α, along with a notable reduction in antioxidative enzymes like SOD, CAT, GSH, and GPx. These findings suggest that MPs exposure significantly disrupts liver function by inducing oxidative stress and inflammation. The results underscore the urgent need for targeted environmental policies and further research.

Towards harmonized ecotoxicological effect assessment of micro- and nanoplastics in aquatic systems

Micro- and nanoplastics are globally important environmental pollutants. Although research in this field is continuously improving, there are a number of uncertainties, inconsistencies and methodological challenges in the effect assessment of micro- and nanoparticles in freshwater systems. The current understanding of adverse effects is partly biased by the use of non-relevant particle types, unsuitable test setups and environmentally unrealistic dose metrics, which does not take into account realistic processes in particle uptake and consequent effects. Here we summarize the current state of the art by compiling the most recent research with the aim to highlight research gaps and further necessary steps towards more harmonized testing systems. In particular, ecotoxicological scenarios need to mirror environmentally realistic particle diversity and bioavailability. Harmonized test setups should include different uptake pathways, exposures and comparisons with natural reference particles. Effect assessments need to differentiate direct physical particle effects, such as lesions and toxicity caused by the polymer, from indirect effects, such as alterations of ambient environmental conditions by leaching, change of turbidity, food dilution and organisms' behavior. Implementation of these suggestions can contribute to harmonization and more effective, evidence-based assessments of the ecotoxicological effects of micro- and nanoplastics.

Microplastics in the surface waters of the northern South China Sea: Interannual variation and potential ecological risks

Microplastic pollution in marine environments has become a global concern due to its potential ecological risks. However, long-term data on microplastic distribution are scare, hindering the assessment of the ecological threats. This study monitored microplastics pollution in the surface water of the northern South China Sea from 2019 to 2023. The average abundance of microplastics exhibited an increasing trend from 2019 to 2021 and a subsequent decrease from 2021 to 2023 in both the Pearl River Estuary and Zhanjiang offshore waters. Conversely, a steady annual decrease was observed in the surface waters of Beibu Gulf from 2020 to 2023. The spatial variability of microplastic hotspot across different years and regions. Microplastics predominantly ranged from 1 to 2 mm in size, with fragments and fibers being the most common shapes and transparent and white colors being the most prevalent. The primary chemical components of microplastics were polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). No significant inter-annual differences were observed in the physicochemical characteristics of microplastics. The pollution load index (PLI) indicated medium to low levels of microplastic pollution, with the potential ecological risk index (PERI) suggesting a low level of ecological risk, implying a minimal threat to the marine ecosystem. This study first revealed the annual variations in microplastic pollution and their potential ecological risks in the northern South China Sea, providing crucial data support for the future management and control of marine microplastic pollution.

Unveiling the impact of biodegradable polylactic acid microplastics on meadow soil health

Soil microplastics (MPs) pollution has garnered considerable attention in recent years. The use of biodegradable plastics for mulching has led to significant quantities of plastic entering agro-ecosystems. However, the effects of biodegradable polylactic acid (PLA) plastics on meadow soils remain underexplored. This study investigates the impacts of PLA-MPs of varying particle sizes and concentrations on soil physicochemical properties, enzyme activities, and microbial communities through a 60-day incubation experiment. PLA-MPs increased the pH, soil organic matter, total nitrogen (TN) and available potassium (AK) content, as well as enhanced the activities of superoxide dismutase (S-SOD), peroxidase (S-POD), soil catalase (S-CAT), β-glucosidase (S-β-GC) and urease (S-UE) activities. Conversely, a decrease in alkaline phosphatase (S-ALP) activity was observed. The influence of PLA-MPs on soil physicochemical properties was more pronounced with larger particle sizes, whereas smaller particles had a greater effect on enzyme activities. Additionally, PLA-MPs led to an increase in the abundance of Acidobacteriota, Chloroflexi, and Gemmatimonadota, while the abundance of Proteobacteria, Actinobacteriota, and Patescibacteria declined. Mantel test analysis showed that changes in microbial community composition affected soil properties such as pH, AK, S-UE and S-β-GC. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2) analysis demonstrated that PLA-MPs modify bacterial metabolic pathways. Our results suggest that particle size and concentration of PLA-MPs differentially affect soil nutrients and microbial community structure and function, with more significant effects observed at larger particle sizes and higher concentrations.

In vitro and in vivo effects of commercial and environmental microplastics on Unio delicatus

Microplastics (MPs) are ubiquitous pollutants in freshwater environments. In this study, freshwater mussels, Unio delicatus, were exposed to both environmental MPs (e-MP) and commercial MPs (c-MP) that include green fluorescent MP (gf-MP), polyethylene (c-PE) and polystyrene (c-PS) at environmental concentrations (5 mg/L and 50 mg/L) over duration of 7 and 30 days. According to in vivo experiment results, both e-MPs and c-MPs induced significant changes in the total hemocyte counts of mussels (p < 0.05). Exposure to high concentrations of e-MPs and c-MPs for 7 days led to decreased cellular glutathione levels in the mussels, while exposure to low concentrations of e-MPs and c-PS for 7 days resulted in increased advanced oxidation protein products (AOPP). Mussels exposed to high concentrations of e-MPs for 30 days exhibited decreases in both glutathione levels and AOPP values. Although no damage was observed in tissues other than gills and digestive gland, histopathological alterations were observed in these tissues following exposure to 50 mg/L c-MPs. Additionally, MPs were observed in the intestine tissues. In vitro experiments using the MTT assay showed no significant difference in cell viability between the MP-exposed group and the control group at tested concentrations, with no observed dose-response relationship (p > 0.05). Nevertheless, certain cells exhibited signs of cell death, such as disrupted cellular structures, condensed nuclei, and loss of cellular integrity. These observations were consistent with mechanical compression, indicating that physical contact with MPs may result in cell damage or death. These findings demonstrate that environmentally relevant concentrations of MPs have toxic effects on freshwater mussels and multiple parameters provide valuable insight for the evaluation of health risks of organisms.

OCTN1 (SLC22A4) as a Target of Heavy Metals: Its Possible Role in Microplastic Threats

Microplastics represent a threat due to their ability to enter the food chain, with harmful consequences for living organisms. The riskiness of these particles is also linked to the release of other contaminants, such as heavy metals. Solute Carriers (SLCs) represent eminent examples of first-level targets of heavy metals due to their localization on the cell surface. Putative targets of heavy metals are the organic cation transporters that form a sub-clade of the SLC22 family. Besides the physiological role in the absorption/release of endogenous organic cations, these transporters are crucial in drug disposition and their interaction with xenobiotics. In this work, the human SLC22A4, commonly known as OCTN1, was used as a benchmark to test interactions with heavy metals released by microplastics, exploiting the proteoliposome tool. The potency of metals to interfere with the OCTN1 function has been evaluated by measuring IC50 values calculated in the micromolar range. The molecular mechanism of interaction has been defined using site-directed mutagenesis and computational analyses. Finally, some chemical and physiological thiol-reacting compounds show the capacity to rescue the metal-inhibited OCTN1 function. The conclusions drawn on OCTN1 can be extended to other members of the SLC22 family and orthologous transporters in fish.

Microplastics in soil: A comprehensive review of occurrence, sources, fate, analytical techniques and potential impacts

Through their accumulation in soils, microplastics have recently become a matter of concern. The aim of this review is to assemble and investigate the recent studies about microplastics in soil by focusing on their sources, occurrence, fate in soil, and analytical methods. The objective is also to clarify and elucidate their potential impacts on soil fauna, plants and microorganisms. In this paper, articles reporting the quantity of microplastics and their characteristics in soil at 62 sites situated across 17 countries were reviewed. The land type, microplastic abundances, types and sizes were compared. We summarized and discussed the sampling and analytical methods used and the variation of microplastic concentration according to their sources. The data showed that microplastic in soil from available global studies ranged from 0 to 3573×103 particles kg-1, with major dominance of polyethylene, polystyrene and polypropylene found in 50, 37 and 32 studies, respectively. The data analysis showed the high migration of small particles, spherical shape with high polymer density in the major studies. We also described the mechanisms controlling the vertical transport of microplastics: agricultural activity (plowing: at a depth between 10 cm (very shallow plowing) and 40 cm (deeper soil tillage)), bioturbation by soil organisms and plants, and leaching that can lead to the contamination of the groundwater. This review elucidated the behavior and fate of microplastics within the soil, serving as a reference for upcoming studies aimed at devising solutions to mitigate the toxicity associated with microplastics in soil.

The role of marine bacteria in modulating the environmental impact of heavy metals, microplastics, and pesticides: a comprehensive review

Bacteria assume a pivotal role in mitigating environmental issues associated with heavy metals, microplastics, and pesticides. Within the domain of heavy metals, bacteria exhibit a wide range of processes for bioremediation, encompassing biosorption, bioaccumulation, and biotransformation. Toxigenic metal ions can be effectively sequestered, transformed, and immobilized, hence reducing their adverse environmental effects. Furthermore, bacteria are increasingly recognized as significant contributors to the process of biodegradation of microplastics, which are becoming increasingly prevalent as contaminants in marine environments. These microbial communities play a crucial role in the colonization, depolymerization, and assimilation processes of microplastic polymers, hence contributing to their eventual mineralization. In the realm of pesticides, bacteria play a significant role in the advancement of environmentally sustainable biopesticides and the biodegradation of synthetic pesticides, thereby mitigating their environmentally persistent nature and associated detrimental effects. Gaining a comprehensive understanding of the intricate dynamics between bacteria and anthropogenic contaminants is of paramount importance in the pursuit of technologically advanced and environmentally sustainable management approaches.

Understanding the Occurrence and Fate of Atmospheric Microplastics and Their Potential Risks to Human Health: Protocol for a Cross-Sectional Analysis

BACKGROUND

Plastic pollution has reached an alarming magnitude, defining the contemporary era as the "Plastic Age." Uncontrolled plastic production and inadequate recycling processes have led to widespread contamination of the environment with micro and nanoplastics.

OBJECTIVE

The study aims to assess the environmental and human health consequences of exposure to microplastic particles (MPs) and their additives among plastic recycling workers in Dhaka. Specifically, it focuses on mapping the management pathways of plastic waste from collection to disposal, analyzing the types of MPs in the environment, and assessing the potential health impacts on plastic recycling workers.

METHODS

A cross-sectional exploratory study design was used, consisting of exposed and nonexposed groups in plastic recycling sites in Dhaka, Bangladesh. The study will establish possible associations between different health consequences and microplastic particle exposure with a systematic approach involving plastic recycling hot spot detection, management pathway mapping, and detecting the presence of environmental MP. MPs and heavy metals will be detected from environmental samples using fluorescence microscopy, Fourier-transform infrared spectroscopy, and inductively coupled plasma mass spectrometry. Human exposure will be assessed by detecting the metabolites of bisphenol and phthalates from urine samples using liquid chromatography-tandem mass spectrometry and thoroughly evaluating endocrine, reproductive, respiratory, and renal functions. The sample size was derived from the mean concentrations of urinary bisphenol and phthalates metabolites, requiring the participation of 168 respondents. A 1:1 exposure to nonexposed stratification would be sufficient to meet our study objectives, considering the conventional level of power and confidence interval. This study protocol (PR#22111) has received approval from the Research Review Committee and Ethical Review Committee of the icddr,b.

RESULTS

The project was funded in August 2022. We started collecting environmental samples in January 2023 and completed participant enrollment, exposure survey, and biological sample collection by December 2023. We enrolled 84 adult plastic recycling workers with at least 5 years of exposure history and 84 nonexposed participants who were not involved with plastic recycling activities. Data analysis is currently underway, and the first results are expected to be submitted for publication in November 2024.

CONCLUSIONS

The findings would provide valuable insights into the adverse impacts of microplastic pollution on both the environment and human health, aiding in better understanding the extent of the issue.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/60289.

Oxidative Stress in Mussel Mytilus trossulus Induced by Different-Sized Plastics

Polyethylene and polystyrene are massively used around the world in various applications and are the most abundant plastic waste. Once in the marine environment, under the influence of physical and chemical factors, plastic products degrade, changing from the size category of macroplastics to microplastics. In order to study the effect of plastic on marine organisms, we modeled the conditions of environmental pollution with different-sized plastic-polystyrene microparticles of 0.9 µm and macro-sized polyethylene fragments of 10 cm-and compared their effect on biochemical parameters in the tissues of the bivalve mollusk Mytilus trossulus. Using biomarkers, it was found that regardless of the size and type of polymer, polystyrene microparticles and polyethylene macrofragments induced the development of oxidative stress in mussels. A significant decrease in the level of lysosomal stability in mussel hemocytes was observed. Increases in the level of DNA damage and the concentration of malonic dialdehyde in the cells of gills and the digestive gland were also shown. The level of total antiradical activity in cells varied and had a tissue-specific character. It was shown that both ingested polystyrene particles and leachable chemical compounds from polyethylene are toxic for mussels.

Potential ecological risk assessment of microplastics in environmental compartments in Mexico: A meta-analysis

Microplastic (MP) environmental contamination has been widely studied in Mexico. However, the evaluation of the associated risk to MPs in environmental compartments is scarce. Therefore, this study addresses this issue using diverse indicators such as the Pollution Load Index (PLI), the Polymer Risk Index (PRI), and the Potential Ecological Risk Index (PERI). The results of a meta-analysis revealed high MP contamination levels in most of the studied compartments, which included marine and estuarine waters, beach sand, freshwater, sediments, and biota. Regarding the risk assessment indicators, PLIs indicated low (56%), dangerous (22%), moderate (12%), and high (10%) levels across compartments. Meanwhile, PRIs displayed concerning values, with 36%, 35%, 20%, and 9% exhibiting dangerous, high, moderate, and low levels, respectively. Thus, high PRI values emphasized the significant rise in MP pollution, largely attributed to high-hazard polymer compositions. Otherwise, PERIs showed low (56%), very dangerous (29%), moderate (6%), high (5%), and dangerous (4%) levels. Thus, the ecological risk in Mexico is widespread and mainly linked to MP abundance, polymer type, environmental matrix, and characteristics of organisms. This study represents the first attempt at MP ecological risk assessment in Mexico, providing crucial insights for developing mitigation strategies to address concerns about MP contamination.

Environmental Contaminants in Fish Products: Food Safety Issues and Remediation Strategies

The intentional or accidental presence of environmental contaminants, such as persistent organic pollutants, metals, and microplastics, can harm the aquatic ecosystem and their living organisms, as well as consumers of seafood. This study provides an overview of marine pollution caused by various chemicals and their toxicity to both the environment and humans. In addition to regulatory limits established for some contaminants, monitoring and management policies should mandate activities such as bioremediation and the use of carbon-based composite photocatalysts to reduce or eliminate these compounds.

Fibrous microplastics in the environment: Sources, occurrence, impacts, and mitigation strategies

Fibrous microplastics (FMPs), a unique class of microplastics, are increasingly recognized as a significant environmental threat due to their ubiquitous presence and potential risks to ecological and human health. This review provides a comprehensive overview of FMPs, including their sources, prevalence in various environmental media, and potential impacts. FMPs, which can be found in over 90 % of certain environmental samples, originate from a diverse range of sources, including synthetic textiles, landfill waste, industrial emissions, and atmospheric deposition. These persistent pollutants pose a threat to both terrestrial and marine ecosystems. Their insidious presence can lead to ingestion by organisms, potentially disrupting ecosystems and posing risks to human health. Addressing the challenge of FMPs requires a multi-faceted approach. Reducing the production and use of synthetic fibers, implementing effective waste management practices, and developing new technologies to remove FMPs from wastewater and the broader environment are all crucial components of the solution. However, further research is essential to fully understand the long-term implications of FMPs on ecosystems and human health, laying the foundation for the development of robust and effective mitigation strategies.

Polystyrene Microplastics Induce Injury to the Vascular Endothelial Through NLRP3-Mediated Pyroptosis

The health risks associated with microplastics have attracted widespread attention. Polystyrene microplastics (PS-MPs) can induce damage to cardiac tissue, while pyroptosis-mediated injury to the vascular endothelial plays a vital role in the pathogenesis of cardiovascular diseases. The study intended to explore the role and mechanism of NLR family pyrin domain containing 3 (NLRP3) mediated pyroptosis in PS-MPs causing the injury of vascular endothelial cells. In vivo, Wistar rats were exposed to 0.5, 5, and 50 mg/kg/d 0.5 μm PS-MPs. In vitro, the human vascular endothelial cells (HUVECs) were used for mechanistic studies. siRNA was used for silencing the NILRP3 gene. H&E staining and flow cytometry were performed to examine the vascular injury and cell membrane damage. The oxidative stress was detected by flow cytometry, immunofluorescence, and corresponding kits. ELISA were used to measure the levels of inflammatory factors. Real-time PCR and western blot were used to measure the expression of pyroptosis signaling pathway. In rats, PS-MPs could cause vascular damage, oxidative stress, and inflammatory response, and activated the pyroptosis signaling pathway. HUVECs exposure to PS-MPs, the vitality decreased in a dose-dependent manner, ROS and MDA were significantly increased while SOD was decreased. PS-MPs induced the onset of pyroptosis signaling pathway in HUVECs. Cell membrane damage and the levels of IL-Iβ and IL-18 in HUVECs significantly increased, those are symbols for the development of pyroptosis. Inhibition of NLRP3-mediated pyroptosis effectively protected HUVECs from PS-MPs-induced damage. Pyroptosis played a vital role in controlling the vascular endothelial injury caused by PS-MPs.

Microplastics predominantly affect gut microbiota by altering community structure rather than richness and diversity: A meta-analysis of aquatic animals

The impacts of microplastics on the gut microbiota, a crucial component of the health of aquatic animals, remain inadequately understood. This phylogenetically controlled meta-analysis aims to identify general patterns of microplastic effects on the alpha diversity (richness and Shannon index), beta diversity, and community structure of gut microbiota in aquatic animals. Data from 63 peer-reviewed articles on the Web of Science were synthesized, encompassing 424 observations across 31 aquatic species. The analysis showed that microplastics significantly altered the community structure of gut microbiota, with between-group distances being 87.75% higher than within-group distances. This effect was significant even at environmentally relevant concentrations (≤1 mg L-1). However, their effects on richness, Shannon index, and beta diversity (community variation) were found to be insignificant. The study also indicated that the effects of microplastics were primarily dependent on their concentration and size, while the phylogeny of tested species explained limited heterogeneity. Furthermore, variations in gut microbiota alpha diversity, beta diversity, and community structure were correlated with changes in antioxidant enzyme activities from the liver and hepatopancreas. This implies that gut microbiota attributes of aquatic animals may provide insights into host antioxidant levels. In summary, this study illuminates the impacts of microplastics on the gut microbiota of aquatic animals and examines the implications of these effects for host health. It emphasizes that microplastics mainly alter the community structure of gut microbiota rather than significantly affecting richness and diversity.

Insights into the seasonal variation, distribution, composition and dynamics of microplastics in the Ganga River ecosystem of Varanasi City, Uttar Pradesh, India

The current study explores the seasonal dynamics of microplastic (MP) pollution in the Ganga River of Varanasi City, Uttar Pradesh, India, focusing on water and sediment samples collected during pre-monsoon and post-monsoon periods. The analysis shows significant variations in MP occurrence, shape dynamics, color distribution, and size composition across diverse sampling sites. During the pre-monsoon season, MP concentrations ranged from 17 to 36 particles/L in water samples and 160 to 312 particles/kg in sediment, indicating a moderate to high level of contamination. Post-monsoon sampling showed higher MP concentrations at most sites, indicating the influence of seasonal hydrological changes on MP distribution. Shifts in MP shape dynamics were observed between seasons, with films, foams, fragments, and filaments showing variable distributions. Similarly, color variations in MPs exhibited site-specific patterns, with white, brown, blue, and other colors being predominant. These findings highlight the diverse sources and compositions of MPs in the river ecosystem, highlighting the complexity of MP pollution dynamics. Polymer-type distributions further elucidated the composition of MPs, with notable contributions from polyethylene terephthalate, rayon, polyester, and polyvinyl chloride. PCA analysis revealed significant shifts in particle size and shape distribution between pre-monsoon and post-monsoon periods in both water and sediment samples, with post-monsoon samples showing an increase in larger particles and filaments. These changes highlighted key factors driving the variance in microplastic contamination across different sites. The prevalence of these polymers features diverse sources of MP pollution, including textiles, packaging materials, and industrial waste. Ongoing monitoring and research are crucial to understanding its sources, distribution, and impact on river ecosystems, essential for protecting aquatic biodiversity and human health.

Micro(nano)plastic and Related Chemicals: Emerging Contaminants in Environment, Food and Health Impacts

Microplastic pollution is a problem of increasing concern in food, and while food safety issues around the world are serious, an increasing number of food safety issues related to microplastics have become the focus of people's attention. The presence of microplastics in food is a worldwide problem, and they are present in all kinds of foods, foods of both animal and plant origin, food additives, drinks, plastic food packaging, and agricultural practices. This can cause problems for both humans and the environment. Microplastics have already been detected in human blood, heart, placenta, and breastmilk, but their effects in humans are not well understood. Studies with mammals and human cells or organoids have given perspective about the potential impact of micro(nano)plastics on human health, which affect the lungs, kidneys, heart, neurological system, and DNA. Additionally, as plastics often contain additives or other substances, the potentially harmful effects of exposure to these substances must also be carefully studied before any conclusions can be drawn. The study of microplastics is very complex as there are many factors to account for, such as differences in particle sizes, constituents, shapes, additives, contaminants, concentrations, etc. This review summarizes the more recent research on the presence of microplastic and other plastic-related chemical pollutants in food and their potential impacts on human health.

Microplastic pollution and nutrient enrichment shift the diet of freshwater macroinvertebrates

Microplastic pollution poses a global threat to freshwater ecosystems, with laboratory experiments indicating potential toxic impacts through chemical toxicity, physical abrasion, and false satiation. Bioplastics have emerged as a potential greener alternative to traditional oil-based plastics. Yet, their environmental effects remain unclear, particularly at scales relevant to the natural environment. Additionally, the interactive impacts of microplastics with other environmental stressors, such as nutrient enrichment, are poorly understood and rarely studied. Under natural conditions organisms might be able to mitigate the toxic effects of microplastics by shifting their diet, but this ability may be compromised by other stressors. This study combines an outdoor mesocosm experiment and stable isotope analysis to determine changes in the trophic niches of three freshwater invertebrate species exposed to conventional (HDPE) and bio-based biodegradable (PLA) microplastics at two concentrations, both independently and combined with nutrient enrichment. Exposure to microplastics altered the isotopic niches of two of the invertebrate species, with nutrient enrichment mediating this effect. Moreover, the effects of microplastics were consistent regardless of their type or concentration. Under enriched conditions, two of the species exposed to microplastics shifted to a specialised diet compared with controls, whereas little difference was observed between the isotopic niches of those exposed to microplastic and controls under ambient nutrient conditions. Additionally, PLA was estimated to support 24 % of the diet of one species, highlighting the potential assimilation of bioplastics by biota and possible implications. Overall, these findings suggest that the toxic effects of microplastics suggested from laboratory studies might not manifest under real-world conditions. However, this study does demonstrate that subtle sublethal effects occur even at environmentally realistic microplastic concentrations. The crucial role of nutrient enrichment in mediating microplastic effects underscores the importance of considering microplastic pollution in the context of other environmental stressors.

The particle effect: comparative toxicity of chlorpyrifos in combination with microplastics and phytoplankton particles in mussel

Lately, the role of microplastics (MP) as vectors for dissolved contaminants and as vehicle for their transfer to aquatic organisms has received attention. Similarly to MP, other inorganic and organic particles may act as passive samplers. However, limited comparative knowledge exists at this respect. In the present study we have comparatively investigated the risk for mussel of MP and the pesticide chlorpyrifos (CPF) alone and in combination with MP and phytoplankton particles of microalgae (MP-CPF and MA-CPF, respectively). We selected MP and microalgae of similar size to expose mussel to the same volume of particles (≈1.5 mm3L-1 ≈ equivalent to 1.5 mg MP L-1) and the same concentration of contaminant (CPF, 7.6 μg L-1). MP were virgin HDPE microparticles (≤10 μm) while the microalgae species was Isochrisis galbana (4-8 μm). Mussels were exposed for 21 days to MP, CPF, MP-CPF and MA-CPF. Then, a suite of neurotoxicity, oxidative stress and oxidative damage biomarkers were measured in samples collected at day 7 and 21. Additionally, these biochemical markers were assessed in an integrated manner with others measured at physiological, immune and cell component level in the same organisms, previously published. Overall, MP did not elicit significant alterations on the majority of parameters measured. In contrast, mussels exposed to CPF, MA-CPF and MP-CPF showed evidence of neurotoxicity and oxidant imbalance at day 7, added to a detrimental physiological condition and immune imbalance at day 21. At the latter time MP-CPF mussels showed greater alterations than CPF or MA-CPF mussels. This suggested a synergistic toxicity of MP combined with CPF greater than that produced by the contaminants alone (MP or CPF) or by MA combined with CPF.

Plastic pollution in agricultural landscapes: an overlooked threat to pollination, biocontrol and food security

Ecosystem services such as pollination and biocontrol may be severely affected by emerging nano/micro-plastics (NMP) pollution. Here, we synthesize the little-known effects of NMP on pollinators and biocontrol agents on the organismal, farm and landscape scale. Ingested NMP trigger organismal changes from gene expression, organ damage to behavior modifications. At the farm and landscape level, NMP will likely amplify synergistic effects with other threats such as pathogens, and may alter floral resource distributions in high NMP concentration areas. Understanding exposure pathways of NMP on pollinators and biocontrol agents is critical to evaluate future risks for agricultural ecosystems and food security.

Perspectives on the Toxic Effects of Micro- and Nanoplastics on the Environment: A Bibliometric Analysis of the 2014 to 2023 Period

Over the past decade, micro- and nanoplastics (MNPs) have garnered significant attention due to their frequent detection in and potential toxic effects on the environment and organisms, making them a serious threat to human health. To comprehensively understand the research on MNPs' toxicity, we employed the R language-based Bibliometrix toolkit (version 4.3.0), VOSviewer (version 1.6.11) and CiteSpace (version 6.3.R1) to perform statistical and visual analyses of 3541 articles pertaining to MNPs' toxicity between 2014 and 2023, which were retrieved from the Web of Science Core Collection (WOSCC) database. The analysis revealed that research related to MNPs' toxicity has experienced a rapid increase in recent years. China's particularly prominent influence in the field of MNPs' toxicity is evidenced by its academic exchanges and the establishment of a mature cooperation system with other countries (regions), such as the USA and Germany. Studies related to MNPs' toxicity are primarily published in leading journals, including the Science of the Total Environment, Environmental Pollution, and the Journal of Hazardous Materials. The Chinese Academy of Sciences was identified as the leading institution in terms of research on MNPs' toxicity, contributing 203 papers to the total number of studies published. Keyword co-occurrence and burst analyses indicated that the current research on MNPs' toxicity mainly focuses on the toxic effects of MNPs on aquatic organisms, the combined toxicity of MNPs and other contaminants, and the toxic effects and mechanisms of MNPs. Future research should integrate computational toxicology and toxicomics to enhance our understanding of MNPs' toxicity mechanisms and assess the potential health risks posed by atmospheric MNPs.

Microplastics caused embryonic growth retardation and placental dysfunction in pregnant mice by activating GRP78/IRE1α/JNK axis induced apoptosis and endoplasmic reticulum stress

Microplastics (MPs), a brand-new class of worldwide environmental pollutant, have received a lot of attention. MPs are consumed by both humans and animals through water, food chain and other ways, which may cause potential health risks. However, the effects of MPs on embryonic development, especially placental function, and its related mechanisms still need to be further studied. We investigated the impact on fetal development and placental physiological function of pregnant mice by consecutive gavages of MPs at 0, 25, 50, 100 mg/kg body weight during gestational days (GDs 0-14). The results showed that continuous exposure to high concentrations of MP significantly reduced daily weight gain and impaired reproductive performance of pregnant mice. In addition, MPs could significantly induce oxidative stress and placental dysfunction in pregnant mice. On the other hand, MPs exposure significantly decreased placental barrier function and induced placental inflammation. Specifically, MPs treatment significantly reduced the expression of tight junction proteins in placentas, accompanied by inflammatory cell infiltration and increased mRNA levels of pro-inflammatory cytokines and chemokines in placentas. Finally, we found that MPs induced placental apoptosis and endoplasmic reticulum (ER) stress through the GRP78/IRE1α/JNK axis, leading to placental dysfunction and decreased reproductive performance in pregnant mice. We revealed for the first time that the effects of MPs on placental dysfunction in pregnant animals. Blocking the targets of MPs mediated ER stress will provide potential therapeutic ideas for the toxic effects of MPs on maternal pregnancy.

Preparation of Block Copolymer-Stabilized Microspheres from Commercial Plastics and Their Use as Microplastic Proxies in Degradation Studies

This study presents a novel one-pot procedure for preparing sub-10 μm poly(ethylene glycol) (MPEG)-stabilized glycol-modified poly(ethylene terephthalate), poly(ethylene terephthalate) (PET), poly(lactic acid) (PLA), polycarbonate, and polycaprolactone (PCL) particles from commercial plastics. The prepared particles can be dried and directly resuspended in water, making them easy to handle and relevant mimics of microplastics. In addition, the method was extended to the preparation of unstabilized PET particles and somewhat larger polyethylene (PE)-based particles. Selected stabilized microparticles were subjected to aerobic biodegradation studies and compared with nonstabilized PET particles. All of the particles exhibited some degradation. For PLA and PET particles, the degradation corresponded well to the amount of surface-stabilizing MPEG groups or known impurities, confirming that these polymers do not degrade under the applied conditions but that the stabilizing groups do. PCL particles degraded relatively rapidly, which is consistent with the literature data and their relatively small size. PE-based particles degraded more than expected if only degradation of the stabilizing groups was taken into account, indicating that the surface chemistry of these particles plays a role in bulk degradation.

The problem of anthropogenic microfibres in karst systems: Assessment of water and submerged sediments

A new worrying micropollutant threathens natural environments: the microfibres (MFs). Natural, regenerated and synthetic MFs have been detected in different environments, as well as in organisms. While synthetic MFs are generally detected in microplastic analyses, natural and regenerated MFs are not taken into account, or are wrongly considered plastics. They are generally considered biodegradable even if their degradation processes in ecosystems are poorly known. Their potential faster degradation could release toxic compounds, and their characteristics could led to a long-term accumulation in the environment. Understanding their dangerousness and the possible impact they could have on ecosystems is fundamental for environment conservation. We collected and investigated water and submerged sediment samples in different caves and springs of the Classical Karst Region (NE Italy), rich in protected habitats and species. MFs were analysed via microscopy and spectroscopy. MFs were found in all samples, highlighting pollution in surface and subterranean habitats of the karst system. MF concentration was higher in submerged sediments respect to waters, highlighting an accumulation of MFs over time. Big microfibres were less abundant, and MF amount increased with the decrease in the considered size. More than 80% of fibres were fluorescent under UV light. Fluorescent MFs were especially transparent, while non-fluorescent ones were mainly black and blue. Most MFs were cellulosic, and synthetic MFs represent only 15-22%, highlighting a significant gap between the MF composition detected in natural environments and the global production of synthetic textiles in recent times. Synthetic MFs were more abundant in waters. Our results improve the knowledge on micropollutants in karst environments, laying the foundations for future research. MF pollution monitoring in karst areas must become a priority for species protection, habitat conservation, and waters management, improving analyses on a larger number of aquatic environments, taking into account the ecological connections between surface and subterranean habitats.

Assessing the ecological consequences of biodegradable plastics: Acute, chronic and multigenerational impacts of poly-3-hydroxybutyrate microplastics on freshwater invertebrate Daphnia magna

Microplastics, pervasive contaminants in freshwater ecosystems, have raised ecological concerns. Efforts are underway to substitute conventional plastics with biodegradable alternatives that should be more easily decomposed in the environment. However, the biodegradation of these alternatives depends on specific conditions such as temperature, humidity, pH, and microorganisms, which are not always met. Consequently, these biodegradable alternatives can also fragment and generate microplastics, which can be ingested and affect biota. In this study, we investigated the acute, chronic, and multigenerational effects of two fractions (particles <63 μm and particles <125 μm) of biodegradable poly-3-hydroxybutyrate (P3HB) at varying concentrations on the inhibition, mortality, reproduction activity, and growth of the freshwater invertebrate Daphnia magna. No acute effects were observed for either size fraction. However, during chronic and multigenerational experiments, an increase in the concentration of P3HB microplastics corresponded with increased mortality, reduced reproductive activity, and slower growth among the mother organisms. Given the important role of D. magna in the food chain, these findings suggest that biodegradable microplastics may indeed negatively affect freshwater ecosystems.

Assessing Aquatic Baseline Toxicity of Plastic-Associated Chemicals: Development and Validation of the Target Plastic Model

We developed a Target Plastic Model (TPM) to estimate the critical plastic burden of organic toxicants in five types of plastics, namely, polydimethylsiloxane (PDMS), polyoxymethylene (POM), polyacrylate (PA), low-density polyethylene (LDPE), and polyurethane ester (PU), following the Target Lipid Model (TLM) framework. By substituting the lipid-water partition coefficient in the TLM with plastic-water partition coefficients to create TPM, we demonstrated that the biomimetic nature of these plastic phases allows for the calculation of critical plastic burdens of toxicants, similar to the notion of critical lipid burdens in TLM. Following this approach, the critical plastic burdens of baseline (n = 115), less-inert (n = 73), and reactive (n = 75) toxicants ranged from 0.17 to 51.33, 0.04 to 26.62, and 1.00 × 10-6 to 6.78 × 10-4 mmol/kg of plastic, respectively. Our study showed that PDMS, PA, POM, PE, and PU are similar to biomembranes in mimicking the passive exchange of chemicals with the water phase. Using the TPM, median lethal concentration (LC50) values for fish exposed to baseline toxicants were predicted, and the results agreed with experimental values, with RMSE ranging from 0.311 to 0.538 log unit. Similarly, for the same data set of baseline toxicants, other widely used models, including the TLM (RMSE: 0.32-0.34), ECOSAR (RMSE: 0.35), and the Abraham Solvation Model (ASM; RMSE: 0.31), demonstrated comparable agreement between experimental and predicted values. For less inert chemicals, predictions were within a factor of 5 of experimental values. Comparatively, ASM and ECOSAR showed predictions within a factor of 2 and 3, respectively. The TLM based on phospholipid had predictions within a factor of 3 and octanol within a factor of 4, indicating that the TPM's performance for less inert chemicals is comparable to these established models. Unlike these methods, the TPM requires only the knowledge of plastic bound concentration for a given plastic phase to calculate baseline toxic units, bypassing the need for extensive LC50 and plastic-water partition coefficient data, which are often limited for emerging chemicals. Taken together, the TPM can provide valuable insights into the toxicities of chemicals associated with environmental plastic phases, assisting in selecting the best polymeric phase for passive sampling and designing better passive dosing techniques for toxicity experiments.