The global odyssey of plastic pollution

Microplastic contamination and ecological risk assessment in sediments and waters of ship-dismantling yards along the Bay of Bengal

This study investigated the extent of microplastic (MP) contamination in sediment and surface water from one of the largest shipbreaking yards along the Bay of Bengal coast. A total of 48 samples (24 each from sediment and water) were collected and analyzed to assess MP abundance, polymer characteristics, sources, and the associated potential ecological risks. MPs were extracted, identified using microscopy and FTIR spectroscopy, and classified by type, color, and polymer composition. MP concentrations averaged 73.54 ± 8.61 items/kg in sediment and 218.56 ± 19.12 items/m3 in water, with fibers being the dominant morphology (87.8-92.1 % in sediment, 91.5-100 % in water). Stations in close to intensive shipbreaking operations exhibited significantly higher abundances. Polymer characterization revealed PET as the dominant type, comprising 37.5 % in water and 25 % in sediment, followed by PS (25 % in both matrices) and PP (12.5 % in water and 25 % in sediment). Ecological risk assessments revealed moderate to considerable contamination levels. Pollution Load Index (PLI) values ranged from 1.02 to 1.433 in sediment and 1.02-1.68 in water. Polymeric Hazard Index (PHI) values reached maximum at 254.37 (sediment) and 265.68 (water), with corresponding Ecological Risk Index (ERI) values reaching 312.88 and 433.06, respectively. Stations S6 and S3, located near areas of intensive shipbreaking activity, exhibited the highest ecological risks. These findings emphasized the urgent need for regulatory intervention and improved waste management.

Multi-matrix approach to microplastic pollution in the bivalve Donax trunculus, sediment and water along the Mediterranean coasts

Plastic pollution is a widespread issue in marine ecosystems worldwide, and at the basin level, the Mediterranean represents one of the main hotspots for plastic debris. Here, we present MPs pollution levels in the bivalve Donax trunculus, commonly known as wedge clam, considering both young and adult individuals, as well as sediment and water matrices across a national scale, covering the Tyrrhenian, Ionian, and Adriatic coasts of Italy. The aim is to provide an overview of MPs pollution in coastal ecosystems and assess whether wedge clams can act as an early warning sentinel for sandy habitats. Results highlighted that the Adriatic and Ionian coasts exhibited higher MPs levels than the Tyrrhenian coast across all matrices, with MPs pollution predominantly consisting of blue acrylic fibers. D. trunculus proved to be an excellent sentinel for MPs pollution in sediment. The findings also revealed that young individuals had more MPs than adults, highlighting potentially severe harm to the growth of marine organisms. As a commercially valuable species, this study underscores the urgent need to further investigate this issue, especially given its critical implications for both marine ecosystem health and human well-being.

Correcting microplastic pollution and risk assessment in Chinese watersheds

Microplastics (MPs) are emerging pollutants that are attracting attention because of their potential threats posed and their widespread presence in the environment. MP pollution in Chinese watersheds requires assessment; however, existing risk models face data-scale biases. By compiling 2,474 samples from 165 articles, we constructed a national dataset on MPs and propose a novel framework that integrates rescaled MP concentrations with MP characteristics to recalibrate MP pollution and ecological risks. The results showed that MP concentrations show substantial variability across seven orders of magnitude, and corrected data offered a more accurate representation of environmental concentrations. MP shapes, polymers, and colors differed among river basins, and population density and precipitation were important drivers of variations in MP concentrations. MP shapes, colors, and sizes that were not previously considered are now included in the risk assessment of MPs. Furthermore, 50 % of the sampling sites were in the dangerous and extremely dangerous ecological risk classes. The concentrations measured at 16.98 % of the sampling sites exceeded the risk threshold, therefore posing ecological and toxicological risks. The assessment framework may provide overall insights into the differences in MP pollution in river basins.

Nano and Microplastics: Unveiling Their Profound Impact on Endocrine Health

Plastics are extensively used materials with a long environmental lifespan, posing significant risks to human health and the environment. Global plastic consumption has surged, with plastic waste expected to triple by 2060. The primary concern is the breakdown of plastics into nano and micro-sized particles, which can enter the body and have been detected in various organs and tissues.This review systematically examines the effects of micro and nanoplastics (MNPs) on the endocrine system using in vitro and in vivo experimental models. Following PRISMA guidelines, articles were sourced from databases like PubMed, Web of Science, and Scopus. After screening for relevance and removing duplicates and non-English articles, 103 articles focusing on the endocrine effects of MNPs were selected.MNPs can disrupt endocrine functions, altering reproductive hormones and gene expression patterns. In vivo exposure to MNPs increases inflammatory markers such as TNF-α, IL-6, IL-1β, and NF-κB, leading to apoptosis, inflammation, and oxidative stress. These disruptions impact the gonads, thyroid glands, and hormone secretion from the pituitary and hypothalamus. Most studies focus on terrestrial animals, with polystyrene being the most commonly used polymer.Future research should explore various plastic polymers, longer exposure durations, a broader range of concentrations, and human-level studies to better understand the toxicity of plastic particles. Reducing exposure to these pollutants requires legal changes, consumer behavior adjustments, and increased public awareness. Understanding the underlying processes can help propose methods to mitigate risks and protect human health.

Interactions of Micro- and Nanoplastics with Biomolecules: From Public Health to Protein Corona Effect and Beyond

Micro- and nanoplastics (M/NPs), as ubiquitous global environmental pollutants, have garnered increasing attention due to their pervasive presence. These particles can interact with biological molecules through various mechanisms, subsequently inducing potential toxic effects on living organisms. This review investigates the hazards of M/NPs and their interactions with biological membranes and proteins, focusing on their interaction mechanisms and potential effects on biomolecular structure and function. Specifically, we summarize the exposure pathways and potential harms of M/NPs, which can enter the human body through ingestion, inhalation, and skin contact, potentially causing toxicity, inflammation responses, oxidative stress, and endocrine disruption. Additionally, we highlight the interaction between M/NPs and biological membranes, which can induce structural changes, including membrane thickening, increased fluidity, and pore formation, thereby compromising membrane integrity and affecting cellular health. Besides, we emphasize the interaction between M/NPs and proteins, suggesting that protein structural changes and corona formation can influence oxidative stress responses and cytotoxicity, thereby impacting cellular functions and viability. Ultimately, suggestions and outlooks for further research are proposed. Overall, this review systematically summarizes current research on the interactions between M/NPs and biomolecules, including their mechanisms and biological effects, providing researchers with a comprehensive understanding of the field.

Understanding the contribution of plastic additive in microplastic toxicity from consumer products using fathead minnow (Pimephales promelas)

Microplastics are ubiquitous in the environment. Once in the environment, these particles are ingested by organisms. The ingestion of microplastics can lead to various adverse effects. Still, what is driving the toxicity of microplastics is not well understood. Microplastics are a diverse suite of contaminants composed of several shapes, polymers, and chemical additives. The chemical additives in plastics are not always considered in toxicity studies despite their widespread presence in plastic products. We exposed fathead minnows (Pimephales promelas) for 60 days to four treatments: polyethylene microplastics with chemical additives, polyethylene microplastics without chemical additives, chemical additive leachates, and a control (no plastic, no additives). The main objective of this experiment was to understand what is driving the toxicity: the plastic itself (particles), the chemical additives, or both. We took samples at 12, 30, and 60 days to measure the accumulation of plastic and their additives, as well as to look for adverse effects via gene expression and measurements of weight, length, and condition index. Fish exposed to plastic with or without additives had plastic in their gastro-intestinal tract. We did not observe accumulation of Bismuth, a pigment we targeted chemically in the polyethylene. We observed no significant differences in weight, length, or condition between treatments at 12, 30, and 60 days. We also observed no differences in survival. We observed a significant difference in the expression of the following genes among treatments: sod1, sod2, gstp1, and esr2b. Significant differences were generally due to a lower relative expression in fish exposed to the plastics with additives and the chemical additives alone. In conclusion, we observed effects at the molecular level that appeared to be driven by plastic additives. Future studies should continue to try to understand the effects of plastics driven by additives and consider them in risk assessment frameworks.

Free Radicals on Aging Microplastics Regulated the Prevalence of Antibiotic Resistance Genes in the Aquatic Environment: New Insight into the Effect of Microplastics on the Spreading of Biofilm Resistomes

The spread of antibiotic resistance genes (ARGs) by microplastics has received a great concern in coexisting "hotspots". Despite most microplastics suffering from natural aging, little is known about the effect of aging microplastics (A-MPs) on ARGs dissemination. Here, we demonstrated significant suppression of A-MPs on ARGs dissemination in natural rivers. Although ARGs and mobile genetic elements (MGEs) were effectively enriched on A-MPs, the relative abundance of ARGs and MGEs on A-MPs as well as in receiving water decreased by approximately 21.4% to 42.3% during a period of 30 days of dissemination. Further investigation revealed that •OH was consistently generated on A-MPs with a maximum value of 0.2 μmol/g. Importantly, scavenging of •OH significantly increased the relative abundance of ARGs and MGEs both on A-MPs and in receiving water 1.4-29.1 times, indicating the vital role of •OH in suppressing ARGs dissemination. Microbial analysis revealed that •OH inhibited the potential antibiotic-resistant bacteria in surface biofilms, such as Pseudomonas and Acinetobacter (with a decrease of 68.8% and 89.3%). These results demonstrated that •OH was extensively produced on A-MPs, which greatly reduced both the vertical and horizontal gene transfer of ARGs. This study provided new insights into the dissemination of ARGs through microplastics in natural systems.

Accumulation of benzotriazole UV-stabilizers in relation to ingested plastics and associated health metrics in Larus gulls feeding at a landfill in Atlantic Canada

Benzotriazole UV-Stabilizers (BZT-UVs), compounds added to plastics to reduce ultraviolet degradation, are considered contaminants of emerging concern given their environmental persistence and documented toxicity in humans and animals. UV328 is a BZT-UV that has been recently listed to Annex A of the Stockholm Convention; therefore, understanding species exposure is critical information to fulfill international and domestic regulatory obligations. We evaluated hepatic accumulation of 12 plastic additives (including nine BZT-UVs) in Larus gulls in Atlantic Canada. BZT-UV accumulation was assessed in relation to ingested plastics, hepatic heavy metal accumulation, and body condition. Ninety-six percent of gulls had at least one BZT-UV at detectable hepatic concentrations. The most frequently detected BZT-UVs were UVP (91.4 %) and UV328 (76 %), suggesting ubiquitous exposure across individuals. We demonstrated interspecific differences in the relationship between ingested plastics and accumulated contaminants, with a positive relationship detected between ingested plastics and both UVP and UV328 in American herring gulls (Larus argentatus smithsonianus), and a positive relationship between hepatic UV328 and Pb concentrations detected in great black-backed gulls (Larus marinus). We provide evidence that Larus gulls feeding at a coastal landfill are highly exposed to BZT-UVs, and that the relationship between ingested plastics and plastic-associated contaminants varies across sympatric species.

Leaf absorption contributes to accumulation of microplastics in plants

Plant absorption is important for the entry of many pollutants into food chains. Although terrestrial microplastics (MPs) can be absorbed by the roots1,2, their upward translocation is slow1. Meanwhile, atmospheric MPs are widely present3,4, but strong evidence on their direct absorption by plants is still lacking. Here, analyses using mass spectrometry detection show the widespread occurrence of polyethylene terephthalate (PET) and polystyrene (PS) polymers and oligomers in plant leaves, and identify that their levels increase with atmospheric concentrations and the leaf growth duration. The concentrations of PET and PS polymers can reach up to 104 ng per g dry weight in leaves at the high-pollution areas studied, such as the Dacron factory and a landfill site, and 102-103 ng per g dry weight of PET and PS can be detected in the open-air-grown leafy vegetables. Nano-sized PET and PS particles in the leaves were visually detected by hyperspectral imaging and atomic force microscopy-infrared spectroscopy. Absorption of the proactively exposed non-labelled, fluorescently labelled or europium-labelled plastic particles by maize (Zea mays L.) leaves through stomatal pathways, as well as their translocation to the vascular tissue through the apoplastic pathway, and accumulation in trichomes was identified using hyperspectral imaging, confocal microscopy and laser-ablation inductively coupled plasma mass spectrometry. Our results demonstrate that the absorption and accumulation of atmospheric MPs by plant leaves occur widely in the environment, and this should not be neglected when assessing the exposure of humans and other organisms to environmental MPs.

Evaluation of phenotypic and behavioral toxicity of micro- and nano-plastic polystyrene particles in larval zebrafish (Danio rerio)

Plastic particles have been found in all environments and it is necessary to understand the risks these particles pose in, and to, the environment. The objectives of this work were to understand the toxic effects of varying size and concentration of polystyrene (PS) micro- and nano-plastics in zebrafish embryos and their fate within the larvae. In this work, larval zebrafish (Danio rerio) were exposed to six sizes (0.05, 0.25, 0.53, 2.1, 6.02, and 10.2 µm diameter) and concentrations (0.0005 to 0.2 µg/µL) of PS micro/nanoplastics particles. The zebrafish embryo toxicity (ZET) and the general and behavioral toxicity (GBT) assays were used to determine particle toxicity in embryos. Behavioral analysis was performed and micro/nanoplastics uptake and organ distribution were assessed. Phenotypic and behavioral toxicity was observed in all exposures with the exception of 0.25 µm particle-exposed larvae. Significant phenotypic toxicity was seen at the highest tested exposure concentration, with some sizes showing potential recovery as time increased in the assay. Behavioral analysis demonstrated a decrease in baseline activity across all micro- and nano-plastic sizes. Significant increases in light-dark responses were recorded in ZET assays of smaller-sized particles and no significant effects were observed at larger sizes. Significant decreases in this response were reported in the GBT assays of all tested sizes with the exception of the 0.05-µm particles. These assays demonstrate the general, developmental, and neurotoxicity of micro/nanoplastics to a model organism, which can be used to infer individual and population-level effects of exposure.

Exploring the Essential Use Concept for Primary Microplastics Regulation in the EU

With the increasing prevalence of plastic pollution, including microplastics (MPs, particles <5 mm), the pursuit of safer and more sustainable alternatives gains increasing traction. While a substantial portion of MPs in the environment arises from the degradation of plastic litter and the wear of polymer-containing materials (secondary MPs), deliberate incorporation of MPs in certain products (primary MPs) also represents a considerable source, and targeted measures can be implemented to minimize human exposure and environmental releases. Improved policies for managing macroplastic waste help mitigate secondary MPs, but addressing primary MPs requires distinct strategies. Globally, various approaches, such as bans or restrictions on primary MPs, have been proposed, including the recent EU regulation under REACH, which groups intentionally added MPs together based on their diverse uses and properties. However, applying the Essential Use Concept (EUC) provides a more refined regulatory approach; balancing environmental health, technical feasibility, and innovation. This perspective explores the potential, challenges, and limitations of implementing the EUC for primary MPs. By examining four use cases─controlled-release medicines, agricultural seed coatings, personal care products, and artificial turf infill─we highlight how the EUC can prioritize essential and beneficial applications while phasing out nonessential uses.

Occurrence, sources, and ecological risk of microplastics in groundwater: Impacts by agricultural activities and atmospheric deposition

Although microplastic (MP) pollution in groundwater is a serious issue, its potential sources and environmental risks are poorly understood. This study identified the sources of MPs in groundwater from a megacity in China. It estimated the environmental risks of MPs using a combination of the pollution load index (PLI), the polymer hazard index (PHI), and the potential ecological risk index (PERI). The groundwater in Shanghai showed high MP abundances, ranging from 3 ± 3 particles/L to 99 ± 19 particles/L. A total of 43 polymer types were detected, of which polypropylene (PP) and polyethylene (PE) were the main polymer types. Groundwater in agricultural areas has the highest level of MP pollution, with >50 % of MPs being identified as PP. Plastic woven bags used in agricultural activities were the primary sources. Similar characteristics of MPs in groundwater from open wells and atmospheric deposition samples suggested that atmospheric deposition was a significant source of MPs in groundwater from open wells. Landfills and construction activities were also recognized as potential MP pollution sources in groundwater. Based on PLI, PHI and PERI analysis, the groundwater in Shanghai exhibited a high MP pollution load, a middle polymer hazard, and a high potential ecological risk level, respectively. The PERI analysis, a comprehensive assessment compared to the PLI and PHI analyses, indicated an overall high ecological risk of MPs in agricultural groundwater. This study advances the knowledge of MP sources and their ecological risks in groundwater, allowing for better MP pollution control in areas with high MP abundance and high risk levels.

Zooming in the plastisphere: the ecological interface for phytoplankton-plastic interactions in aquatic ecosystems

Phytoplankton is an essential resource in aquatic ecosystems, situated at the base of aquatic food webs. Plastic pollution can impact these organisms, potentially affecting the functioning of aquatic ecosystems. The interaction between plastics and phytoplankton is multifaceted: while microplastics can exert toxic effects on phytoplankton, plastics can also act as a substrate for colonisation. By reviewing the existing literature, this study aims to address pivotal questions concerning the intricate interplay among plastics and phytoplankton/phytobenthos and analyse impacts on fundamental ecosystem processes (e.g. primary production, nutrient cycling). This investigation spans both marine and freshwater ecosystems, examining diverse organisational levels from subcellular processes to entire ecosystems. The diverse chemical composition of plastics, along with their variable properties and role in forming the "plastisphere", underscores the complexity of their influences on aquatic environments. Morphological changes, alterations in metabolic processes, defence and stress responses, including homoaggregation and extracellular polysaccharide biosynthesis, represent adaptive strategies employed by phytoplankton to cope with plastic-induced stress. Plastics also serve as potential habitats for harmful algae and invasive species, thereby influencing biodiversity and environmental conditions. Processes affected by phytoplankton-plastic interaction can have cascading effects throughout the aquatic food web via altered bottom-up and top-down processes. This review emphasises that our understanding of how these multiple interactions compare in impact on natural processes is far from complete, and uncertainty persists regarding whether they drive significant alterations in ecological variables. A lack of comprehensive investigation poses a risk of overlooking fundamental aspects in addressing the environmental challenges associated with widespread plastic pollution.

Effects of Aging Biodegradable Agricultural Films on Soil Physicochemical Properties and Heavy Metal Speciation

Through soil incubation experiments, the effects of aged PBAT + PLA (polybutylene adipate terephthalate + polylactic acid) film fragments were analyzed. Surface characteristics and chemical structures of the films changed significantly after one (T2) and two years (T1) of aging compared to new films (T3). Both new and aged fragments reduced soil pH, altered enzyme activities, and influenced dissolved organic matter (DOM) fluorescence. Alkaline phosphatase activity declined by 33.2%, 23.8%, and 11.6% for T1, T2, and T3, respectively, while urease and sucrase activities increased in a time-dependent manner. The degree of soil humification rose by 66.4%, 60.4%, 49.3%, and 88.6% for T1, T2, T3, and T4, respectively, compared to the control (CK). Aged films exhibited stronger DOM fluorescence intensity than new films. Tessier extraction analysis revealed a decrease in exchangeable Cd by 22.9%, 13.1%, and 10.2% for T1, T2, and T3, respectively, while organically bound Cu increased. Correlation analysis indicated a significant positive relationship between soil humification and heavy metal bioavailability. These findings provide insight into the ecological effects of biodegradable agricultural films, offering a theoretical foundation for assessing their environmental risks and safety.

Biochar-mediated remediation of low-density polyethylene microplastic-polluted soil-plant systems: Role of phosphorus and protist community responses

While the prevalent utilization of plastic products has enabled social advancement, the concomitant microplastics (MPs) pollution presents a serious threat to environmental security and public health. Protists, as regulators of soil microorganisms, are also capable of responding most rapidly to changes in the soil environment. The amelioration mechanisms of biochar in the soil-plant systems polluted by low-density polyethylene microplastics (LDPE-MPs) and the response of protist communities in the soil-plant systems polluted by MPs remain unclear. In this field experiment, the same concentration of biochar (2 %) was applied to remediate different concentrations (1 % and 10 %) of LDPE-MPs pollution in cherry radish soil. The main results indicate that, when compared with the treatment of applying biochar to address high-level LDPE-MPs polluted soil (BP2), the remediation of low-level LDPE-MPs polluted soil by biochar (BP1) led to a 62.02 % reduction in soil available phosphorus. Meanwhile, the abundance of phoD and the activity of alkaline phosphatase increased by 127.75 % and 22.57 % respectively. Moreover, in contrast to BP2, the root biomass and phosphorus content of cherry radish in BP1 increased by 52.80 % and 42.86 % respectively. For protist communities, their structure, niche width, and assembly were altered. The interaction between biochar and LDPE-MPs influenced phosphorus cycling, and protists were closely associated with these processes. Therefore, soil phosphorus cycling indicators and protist community may be important indicators for biochar amelioration on soil MPs pollution. The study highlights the importance of considering these factors for better farmland management in the context of MPs pollution, which is significant for sustainable agriculture and environmental protection.

Thermoformed, thermostable, waterproof and mechanically robust cellulose-based bioplastics enabled by dynamically reversible thia-Michael reaction

Cellulose is a renewable biodegradable polymer derived from abundant natural resources. Substituting petroleum-based polymers with cellulose-based bioplastics is an effective way to alleviate environmental issues like resource depletion and white pollution. However, challenges such as poor thermostability, difficulty in thermoforming and water sensitivity seriously hinder the fabrication and use of cellulose-based bioplastics. Herein, a thermoformed, thermostable, waterproof and mechanically robust cellulose-based bioplastic (H-HEC) is fabricated by introducing thia-Michael-based reversible crosslinked structure into hydroxyethyl cellulose. This is the first instance of integrating thia-Michael-based crosslinked structure into cellulose derivatives. The resulting H-HEC can be thermoformed and remolded without adding any plasticizers. Besides, the obtained H-HEC exhibit excellent overall properties, such as a high thermal decomposition temperature of 366 °C, a high water contact angle of 108°, a high transmittance of 90 % and good mechanical properties. Additionally, H-HEC combines impressive transparency with effective UV-shielding properties. We envision that this work provides a novel method to prepare thermoformable cellulose-based bioplastics with good water resistance, thermostability, transparency and mechanical properties. The combined thermoformability and superior overall performances will promote the practical application of cellulose-based bioplastics and contribute to the replacement of petroleum-based polymer by cellulose-based bioplastics.

"Tire plastisphere" in aquatic ecosystems: Biofilms colonizing on tire particles exhibiting a distinct community structure and assembly compared to conventional plastisphere

Tire particles (TPs) significantly contribute to microplastics in aquatic ecosystems, which has recently attracted ecological concerns worldwide. Numerous studies have shown that biofilms on microplastics harbor unique species and harmful functions, but it remains unclear whether TPs could offer distinct niches for biofilms compared to conventional microplastics (CP). This study investigated the succession and assembly of biofilms on TPs compared with CP over 60 days. Our results showed the community structures of biofilms on TPs and CP were distinct. Intriguingly, a greater structural dissimilarity was observed between TPs-associated communities and natural biofilms compared to that between CP-associated communities and natural biofilms. This dissimilarity became more pronounced as biofilms progressed through succession. Furthermore, the bacterial community on the TPs exhibits a network of greater complexity, more stable structure, and higher activity than that on the CP, but the pattern was reversed in the eukaryotic community. Deterministic processes had a more critical impact on bacterial communities on TPs, whereas distinct stochastic processes controlled eukaryotic communities on TPs (dispersal limitation) and CP (undominated processes). Altogether, this study tentatively introduced the term "tire plastisphere" (i.e., TP-attached biofilms), emphasizing TPs could serve as more artificial microbial habitats and pose potential risks in disturbing aquatic ecology.

Heterogeneous seafloor deposition of heavy microplastics in the North Pacific estimated over 65 years

Marine plastic pollution has been a public concern for many decades; however, transport processes of heavy microplastics to the seafloor have long been overlooked given the difficulties in sampling and modeling. The distribution of heavy microplastic deposition on the seafloor in the North Pacific for 65 years since 1951, was estimated using a particle tracking model with 577,143,840 particles. The model revealed that 22 % of heavy microplastics were deposited over 100 km offshore from their release locations. Strong currents, including the Kuroshio Current and Equatorial Counter Current, advected the heavy microplastics offshore; however, the behaviors of different-sized microplastics with different sinking velocities made the seafloor deposition heterogeneous. The seafloor was separated into six (three) clusters based on the origins (composition of sinking velocity categories) of the deposited microplastics. Deposited microplastics showed a rapid increase since the 2000s even for the open ocean far from emission sources.

Unveiling the mechanism of micro-and-nano plastic phytotoxicity on terrestrial plants: A comprehensive review of omics approaches

Micro-and-nano plastics (MNPs) are pervasive in terrestrial ecosystems and represent an increasing threat to plant health; however, the mechanisms underlying their phytotoxicity remain inadequately understood. MNPs can infiltrate plants through roots or leaves, causing a range of toxic effects, including inhibiting water and nutrient uptake, reducing seed germination rates, and impeding photosynthesis, resulting in oxidative damage within the plant system. The effects of MNPs are complex and influenced by various factors including size, shape, functional groups, and concentration. Recent advancements in omics technologies such as proteomics, metabolomics, transcriptomics, and microbiomics, coupled with emerging technologies like 4D omics, phenomics, spatial transcriptomics, and single-cell omics, offer unprecedented insight into the physiological, molecular, and cellular responses of terrestrial plants to MNPs exposure. This literature review synthesizes current findings regarding MNPs-induced phytotoxicity, emphasizing alterations in gene expression, protein synthesis, metabolic pathways, and physiological disruptions as revealed through omics analyses. We summarize how MNPs interact with plant cellular structures, disrupt metabolic processes, and induce oxidative stress, ultimately affecting plant growth and productivity. Furthermore, we have identified critical knowledge gaps and proposed future research directions, highlighting the necessity for integrative omics studies to elucidate the complex pathways of MNPs toxicity in terrestrial plants. In conclusion, this review underscores the potential of omics approaches to elucidate the mechanisms of MNPs-phytotoxicity and to develop strategies for mitigating the environmental impact of MNPs on plant health.

Impacts of wind forcing on microplastics kinematic in a sensitive water area

Microplastics (MPs) have been found in different environmental department globally, and the threat to organisms posed by MPs is also widely recognized. Kinematic characteristics of low-density fiber MPs in Poyang Lake under different due-south wind were calculated by combining hydrodynamic model with particle tracking model in this study. Poyang Lake is divided into north lake and south lake for study based on its topographic and hydrodynamic characteristics, and the results are as follows: the critical wind speeds causing vertical mixing of MPs in the water column ranges from 6 to 9 m·s-1 in the north lake, while it is >9 m·s-1 in the south lake, and the MPs beaching rate decreases by 7.08 %/(m·s-1) as the due-south wind speed increases. The MPs speed is mainly affected by surface current, while the direction of the velocity is more affected by wind. The MPs velocity in the south lake is only 27.10 % of that in the north lake, and the direction is more dispersed, so the due-south wind concentrates the direction of MPs velocity more to the north in the south lake. The northern wards movement of MPs resulted in a noticeable decrease in FS in the south lake, with FS decreasing by 0.10 for every 1 m·s-1 increase in wind speed, and therefore, the due-south wind reduces the ecological risk posed by MPs through reducing the range of movement and retention time. However, since the FS in the north lake has been close to the minimum value of 1, the reduction of the FS is not significant, and the wind reduces the risk mainly by shortening the retention time of the MPs. Therefore, the ecological risk caused by MPs in Poyang Lake under no or weak wind conditions should be taken into consideration.

Microplastic contamination in Chinese topsoil from 1980 to 2050

China's soil is experiencing significant microplastic contamination. We developed a machine-learning model to assess microplastic pollution from 1980 to 2050. Our results showed that the average abundance of microplastics in topsoil increased from 45 items per kilogram of soil in 1980 to 1156 items by 2018, primarily due to industrial growth (39 %), agricultural film usage (30 %), tire wear (17 %), and domestic waste (14 %). During the same period, microplastic levels in cropland rose from 98 to 2401 items per kilogram of soil, and exposure levels for the Chinese population increased from 808 to 3168 items per kilogram. By 2050, a reduction in the use of agricultural films is expected to decrease cropland contamination by half. However, overall levels are anticipated to remain steady due to other persistent sources, indicating a continued spread of microplastics into subterranean environments, water bodies, and human systems. This study highlights China's microplastic challenges and suggests potential global trends, emphasizing the need for increased awareness and intervention worldwide.

Meta-analysis shows that microplastics affect ecosystem services in terrestrial environments

To date, the understanding of the risks and impacts of microplastics (MPs) on terrestrial ecosystems remains limited, primarily due to most studies focusing on single ecosystem service. This study addressed this gap by conducting an integrative meta-analysis of 128 studies to explore the multifaceted impacts of MPs on various ecosystem services, including plant productivity, soil carbon (C) sequestration, microbial biodiversity, soil fertility, microbial biomass, and enzyme activity. We found that MPs reduced plant productivity service by 14.5 %, microbial biodiversity service by 3.4 %, and soil fertility service by 8.2 %, while soil C sequestration service increased by 12.2 %. No significant effects were observed on microbial biomass and enzyme activity services. Additionally, MPs of different types and shapes influenced the ecosystem services differently, with fiber, fragment, and round-shaped MPs decreasing the plant productivity service by 22.0 %, 14.6 %, and 12.7 %, respectively. Correlation analysis revealed intricate relationships between MPs properties and the ecosystem services. Our findings also revealed complex interdependencies among the ecosystem services induced by MPs application. We observed that the plant productivity service was negatively correlated with the soil C sequestration service, but positively correlated with microbial biodiversity, microbial biomass, and enzyme activity services. Together, our study emphasized the need for targeted research to develop mitigation strategies addressing the multifaceted effects of MPs to terrestrial ecosystems.

Sandstorms contribute to the atmospheric microplastic pollution: Transport and accumulation from degraded lands to a megacity

Surface dust from degraded lands is a major global aerosol source, mobilized by meteorological events like sandstorms. Microplastics (MPs) in dust can be enriched in the atmosphere and transported over long distances to sensitive regions during sandstorms. This study was conducted in a megacity frequently impacted by sandstorms in spring, exploring the influx, characteristics, enrichment mechanism, and transport pathway of sandstorm-derived MPs. The deposition rate of these MPs reached 1823.65 ± 892.53 items·m-2·d-1, predominantly consisting of low-density polymers and those mainly used in synthetic fiber, with an average size of 60.75 µm. Compared to MPs in annual atmospheric deposition, these MPs were smaller and contained a higher proportion of potentially harmful polymers. These factors could increase exposure risks for residents from sandstorm-derived MPs, along with distinct meteorological and ecological effects. Backward trajectory analysis suggested the observed sandstorms originated from the Mongolian Plateau, over 1000 km away. Comparisons of MPs from surface-collected dust on the Mongolian Plateau with sandstorms-delivered MPs revealed the transport was determined by MP shape, size, and density. This study highlights the critical role of sandstorms in the MP atmospheric cycling, emphasizing the extensive impacts of MPs and the need for coordinated mitigation efforts across regions.

Airborne micro- and nanoplastics: emerging causes of respiratory diseases

Airborne micro- and nanoplastics (AMNPs) are ubiquitously present in human living environments and pose significant threats to respiratory health. Currently, much research has been conducted on the relationship between micro- and nanoplastics (MNPs) and cardiovascular and gastrointestinal diseases, yet there is a clear lack of understanding regarding the link between AMNPs and respiratory diseases. Therefore, it is imperative to explore the relationship between the two. Recent extensive studies by numerous scholars on the characteristics of AMNPs and their relationship with respiratory diseases have robustly demonstrated that AMNPs from various sources significantly influence the onset and progression of respiratory conditions. Thus, investigating the intrinsic mechanisms involved and finding necessary preventive and therapeutic measures are crucial. In this review, we primarily describe the fundamental characteristics of AMNPs, their impact on the respiratory system, and the intrinsic toxic mechanisms that facilitate disease development. It is hoped that this article will provide new insights for further research and contribute to the advancement of human health.

Transport of reduced PBAT microplastics in saturated porous media: Synergistic effects of enhanced surface energy and roughness

Microplastic (MP) pollution presents significant global environmental challenges, exacerbated by reduction aging processes in anoxic environments, thereby increasing environmental risks and potential threats to human health. However, the mechanisms underlying the transport of reduced MPs remain poorly understood. In this study, laboratory-scale column experiments were conducted to investigate the transport behavior of polybutylene adipate terephthalate (PBAT), a common biodegradable MPs, and its reduced products obtained through the aging process mediated by two typical reducing agents, NaBH4 and Na2S, under varying conditions (ionic strength (IS), divalent cations, and low molecular weight organic acids (LMWOAs)). The results indicated that reduction aging improved the hydrophilicity of PBAT by increasing the surface roughness (roughness factor increased from 1.300 to 1.642) and surface energy (from 51.80 to 107.03 mN m-1), thereby increasing the mobility of reduced PBAT (with recovery rate increased from 53.77 % to 63.18 %). Increased IS decreased the mobility of reduced PBAT by decreasing the surface negative charge density. Divalent cations inhibited the mobility of both pristine and reduced PBAT in porous media, with pristine PBAT, containing more oxygen functional groups, exhibiting stronger inhibition. Furthermore, LMWOAs promoted the retention of reduced PBAT in porous media, which was dependent on the type of LMWOAs. This study revealed the alterations in MPs properties caused by reduction aging and their effects on transport mechanisms, offering new insights into the transport behavior and environmental risks of reduced MPs.

Soft-Rigid Construction of Mechanically Robust, Thermally Stable, and Self-Healing Polyimine Networks with Strongly Recyclable Adhesion

Reversible and recyclable thermosets have garnered increasing attention for their smart functionality and sustainability. However, they still face challenges in balancing comprehensive performance and dynamic features. Herein, silicon (Si)─oxygen (O) and imidazole units covalent bonds are coupled to generate a new class of bio-polyimines (Bio-Si-PABZs), to endow them with high performance and excellent reprocessing capability and acid-degradability. By tailoring the molar content of diamines, this Bio-Si-PABZs displayed both a markedly high glass transition temperature (162 °C) and a high char yield at 800 °C in an oxygen atmosphere (73.1%). These Bio-Si-PABZs with their favorable properties outperformed various previously reported polyimines and competed effectively with commercial fossil-based polycarbonate. Moreover, the scratch (≈10 µm) on the surface of samples can be self-healing within only 2 min, and an effective "Bird Nest"-to-"Torch" recycling can also be achieved through free amines solution. Most importantly, a bio-based siloxane adhesive derived from the intermediate Bio-Si-PABZ-1 by acidic degradation demonstrated broad and robust adhesion in various substrates, with values reaching up to ≈3.5 MPa. For the first time, this study lays the scientific groundwork for designing robust and recyclable polyimine thermosets with Si─O and imidazole units, as well as converting plastic wastes into thermal-reversibility and renewable adhesives.

Unscrambling why plastics aren't detectable in chicken eggs

Several food groups have been reported to contain varying concentrations of plastics. This study was designed to quantitatively investigate for the first time in Australia the presence of plastics in store-bought chicken eggs. Three commonly consumed brands of free-range, free-range organic, barn-laid and backyard (home-laid) chicken egg samples were analyzed for seven common polymers (i.e., polypropylene, polyethylene, polyvinyl chloride, polyethylene terephthalate, polystyrene, poly-(methylmethacrylate) and polycarbonate). Samples were extracted by enzyme digestion and pressurized liquid extraction, followed by quantitative analysis through double-shot microfurnace pyrolysis coupled to gas chromatography-mass spectrometry. No plastics were detected at concentrations > limit of detection (LOD) (from 0.04 μg/g for PS to 0.22 μg/g for PVC) in the egg samples analyzed, regardless of brand and category, suggesting limited exposure of Australians to plastics from consuming eggs This study provides valuable baseline data and underscores the importance of continued monitoring to ensure the safety and integrity of food supplies in the face of rising environmental plastic pollution.

Microplastics at an environmentally relevant dose enhance mercury toxicity in a marine copepod under multigenerational exposure: Multi-omics perspective

Here, we subjected the marine copepod Tigriopus japonicus to environmentally-relevant concentrations of microplastics (MPs) and mercury (Hg) for three generations (F0-F2) to investigate their physiological and molecular responses. Hg accumulation and phenotypic traits were measured in each generation, with multi-omics analysis conducted in F2. The results showed that MPs insignificantly impacted the copepod's development and reproduction, however, which were significantly compromised by Hg exposure. Interestingly, MPs significantly increased Hg accumulation and consequently aggravated this metal toxicity in T. japonicus, demonstrating their carrier role. Multi-omics analysis indicated that Hg pollution produced numerous toxic events, e.g., induction of apoptosis, damage to cell/organ morphogenesis, and disordered energy metabolism, ultimately resulting in retarded development and decreased fecundity. Importantly, MPs enhanced Hg toxicity mainly via increased oxidative apoptosis, compromised cell/organ morphogenesis, and energy depletion. Additionally, phosphoproteomic analysis revealed extensive regulation of the above processes, and also impaired neuron activity under combined MPs and Hg exposure. These alterations adversely affected development and reproduction of T. japonicus. Overall, our findings should offer novel molecular insights into the response of T. japonicus to long-term exposure to MPs and Hg, with a particular emphasis on the carrier role of MPs on Hg toxicity.

Estimating fossil carbon contributions from chemicals and microplastics in Sweden's urban wastewater systems: A model-based approach

The importance of including fossil carbon in greenhouse gas emission assessments from wastewater treatment plants (WWTPs) is highlighted in the 2019 Intergovernmental Panel for Climate Change (IPCC) guidelines revision and underpinned by an increasing number of experimental studies. The present study introduces a model-based approach to estimate fossil carbon flows within Sweden's urban wastewater system, employing data on chemical and polymeric material flows as a starting point. Our findings show that fossil carbon constitutes approximately 12-17 % of the total carbon emissions to sewer systems. This result aligns with experimental data, which shows fossil carbon contributions to WWTP influents ranging from 4 to 28 %. Our analysis further indicates that microplastics contribute about 13 % of the fossil carbon influx to Swedish WWTPs, while organic chemicals account for the remaining 83 %.

Topic modeling discovers trending topics in global research on the ecosystem impacts of microplastics

The ecological threats of microplastics (MPs) have sparked research worldwide. However, changes in the topics of MP research over time and space have not been evaluated quantitatively, making it difficult to identify the next frontiers. Here, we apply topic modeling to assess global spatiotemporal dynamics of MP research. We identified nine leading topics in current MP research. Over time, MP research topics have switched from aquatic to terrestrial ecosystems, from distribution to fate, from ingestion to toxicology, and from physiological toxicity to cytotoxicity and genotoxicity. In most of the nine leading topics, a disproportionate amount of independent and collaborative research activity was conducted in and between a few developed countries which is detrimental to understanding the environmental fates of MPs in a global context. This review recognizes the urgent need for more attention to emerging topics in MP research, particularly in regions that are heavily impacted but currently overlooked.

Biodegradation of low-density polyethylene by mixed fungi composed of Alternaria sp. and Trametes sp. isolated from landfill sites

With the development of industry and modern manufacturing, nondegradable low-density polyethylene (LDPE) has been widely used, posing a rising environmental hazard to natural ecosystems and public health. In this study, we isolated a series of LDPE-degrading fungi from landfill sites and carried out LDPE degradation experiments by combining highly efficient degrading fungi in pairs. The results showed that the mixed microorganisms composed of Alternaria sp. CPEF-1 and Trametes sp. PE2F-4 (H-3 group) had a greater degradation effect on heat-treated LDPE (T-LDPE). After 30 days of inoculation with combination strain H-3, the weight loss rate of the T-LDPE film was approximately 154% higher than that of the untreated LDPE (U-LDPE) film, and the weight loss rate reached 0.66 ± 0.06%. Environmental scanning electron microscopy (ESEM) and Fourier transform infrared spectroscopy (FTIR) were used to further investigate the biodegradation impacts of T-LDPE, including the changes on the surface and depolymerization of the LDPE films during the fungal degradation process. Our findings revealed that the combined fungal treatment is more effective at degrading T-LDPE than the single strain treatment, and it is expected that properly altering the composition of the microbial community can help lessen the detrimental impact of plastics on the environment.

Increased ingestion and toxicity of polyamide microplastics in Nile tilapia with increase of salinity

Microplastics pollution and salinity intrusion in freshwater ecosystem is one of the worldwide climate change consequences those have negative impacts on the physiology of aquatic organisms. Hence, a 15-day experiment was carried out where Nile tilapia (Oreochromis niloticus) was exposed to different salinity gradients i.e. 0 ‰, 3 ‰, 6 ‰, 9 ‰, and 12 ‰ alone and along with 10 mg/L polyamide microplastics (PA-MP) in order to measure its effects on the hematology, gill, and intestinal morphology. The results exhibited that all the fish treated with PA-MP ingested microplastics and the quantity of accumulation was significantly greater in higher salinity gradients (9 ‰ and 12 ‰). In addition, the PA-MP treated fish showed increased glucose level and at the same time reduced hemoglobin concentration with the increase of salinity. The percentages of abnormalities in erythrocytes both cellular (twin, teardrop and spindle shaped) and nuclear (notched nuclei, nuclear bridge and karyopyknosis) significantly enhanced with PA-MP exposure again in higher salinity treatments (9 ‰ and 12 ‰). The principal component analysis (PCA) exhibited that the addition of 10 mg/L PA-MP negatively affected the hematology of Nile tilapia than that of salinity treatments alone. Besides, the exposure of PA-MP in 9 ‰ and 12 ‰ salinity gradients escalated the severity of histological damages in gills and intestine. Overall, this experiment affirms that the increase of salinity enhanced the microplastics ingestion and toxicity in Nile tilapia, therefore, PA-MP possibly is addressed as additional physiological stressors along with increased salinity gradients in environment.

Ceratophyllum demersum alleviates microplastics uptake and physiological stress responses in aquatic organisms, an overlooked ability

It has been demonstrated that microplastics (MPs) may be inadvertently ingested by aquatic animals, causing harm to their physiological functions and potentially entering the food chain, thereby posing risks to human food safety. To achieve an environmentally friendly and efficient reduction of MPs in freshwater environments, this experiment investigates the depuration effect of C. demersum on MPs using three common aquatic animals: Macrobrachium nipponense, Corbicula fluminea, and Bellamya aeruginosa as research subjects. The amounts of MPs, digestive enzyme activity, oxidative stress index, and energy metabolism enzyme activity in the digestive and non-digestive systems of three aquatic animals were measured on exposure days 1, 3, and 7 and on depuration days 1 and 3. The results indicated that the depuration effect of C. demersum and the species interaction were significant for the whole individual. Concerning digestive tissue, C. demersum was the most effective in purifying B. aeruginosa. When subjected to short-term exposure to MPs, C. demersum displayed a superior depuration effect. Among non-digestive tissues, C. demersum exhibited the earliest purifying effect on C. fluminea. Additionally, C. demersum alleviated physiological responses caused by MPs. In conclusion, this study underscores C. demersum as a promising new method for removing MPs from aquatic organisms.

Biochar immobilized hydrolase degrades PET microplastics and alleviates the disturbance of soil microbial function via modulating nitrogen and phosphorus cycles

Microplastics (MPs) pose an emerging threat to soil ecological function, yet effective solutions remain limited. This study introduces a novel approach using magnetic biochar immobilized PET hydrolase (MB-LCC-FDS) to degrade soil polyethylene terephthalate microplastics (PET-MPs). MB-LCC-FDS exhibited a 1.68-fold increase in relative activity in aquatic solutions and maintained 58.5 % residual activity after five consecutive cycles. Soil microcosm experiment amended with MB-LCC-FDS observed a 29.6 % weight loss of PET-MPs, converting PET into mono(2-hydroxyethyl) terephthalate (MHET). The generated MHET can subsequently be metabolized by soil microbiota to release terephthalic acid. The introduction of MB-LCC-FDS shifted the functional composition of soil microbiota, increasing the relative abundances of Microbacteriaceae and Skermanella while reducing Arthobacter and Vicinamibacteraceae. Metagenomic analysis revealed that MB-LCC-FDS enhanced nitrogen fixation, P-uptake and transport, and organic-P mineralization in PET-MPs contaminated soil, while weakening the denitrification and nitrification. Structural equation model indicated that changes in soil total carbon and Simpson index, induced by MB-LCC-FDS, were the driving factors for soil carbon and nitrogen transformation. Overall, this study highlights the synergistic role of magnetic biochar-immobilized PET hydrolase and soil microbiota in degrading soil PET-MPs, and enhances our understanding of the microbiome and functional gene responses to PET-MPs and MB-LCC-FDS in soil systems.

Environmental fate of microplastics in high-altitude basins: the insights into the Yarlung Tsangpo River Basin

Microplastics (MPs) have been found in remote high-altitude areas, but the main source and migration process remained unclear. This work explored the characteristics and potential sources of MPs in the Yarlung Tsangpo River Basin. The average abundances of MPs in water, sediment, and soil samples were 728.26 ± 100.53 items/m3, 43.16 ± 5.82 items/kg, and 61.92 ± 4.29 items/kg, respectively, with polypropylene and polyethylene as the main polymers. The conditional fragmentation model revealed that the major source of MPs lower than 4000 m was human activities, while that of higher than 4500 m was atmospheric deposition. Community analysis was further conducted to explore the migration process and key points of MPs among different compartments in the basin. It was found that Lhasa (3600 m) and Shigatse (4100 m) were vital sources of MPs inputs in the midstream and downstream, respectively. This work would provide new insights into the fate of MPs in high-altitude areas.

Plastic pollution affects ecosystem processes including community structure and functional traits in large rivers

Plastics in aquatic ecosystems rapidly undergo biofouling, giving rise to a new ecosystem on their surface, the 'plastisphere.' Few studies quantify the impact of plastics and their associated community on ecosystem traits from biodiversity and functional traits to metabolic function. It has been suspected that impacts on ecosystems may depend on its state but comparative studies of ecosystem responses are rare in the published literature. We quantified algal biomass, bacterial and algal biodiversity (16S and 18S rRNA), and metabolic traits of the community growing on the surface of different plastic polymers incubated within rivers of the Lower Mekong Basin. The rivers selected have different ecological characteristics but are similar regarding their high degree of plastic pollution. We examined the effects of plastics colonized with biofilms on ecosystem production, community dark respiration, and the epiplastic community's capability to influence nitrogen, phosphorus, organic carbon, and oxygen in water. Finally, we present conceptual models to guide our understanding of plastic pollution within freshwaters. Our findings showed limited microalgal biomass and bacterial dominance, with potential pathogens present. The location significantly influenced community composition, highlighting the role of environmental conditions in shaping community development. When assessing the effects on ecosystem productivity, our experiments showed that biofouled plastics led to a significant drop in oxygen concentration within river water, leading to hypoxic/anoxic conditions with subsequent profound impacts on system metabolism and the capability of influencing biogeochemical cycles. Scaling our findings revealed that plastic pollution may exert a more substantial and ecosystem-altering impact than initially assumed, particularly in areas with poorly managed plastic waste. These results highlighted that the plastisphere functions as a habitat for biologically active organisms which play a pivotal role in essential ecosystem processes. This warrants dedicated attention and investigation, particularly in sensitive ecosystems like the Mekong River, which supports a rich biodiversity and the livelihoods of 65 million people.

The environmental effects of microplastics and microplastic derived dissolved organic matter in aquatic environments: A review

Currently, microplastics (MPs) have ubiquitously distributed in different aquatic environments. Due to the unique physicochemical properties, MPs exhibit a variety of environmental effects with the coexisted contaminants. MPs can not only alter the migration of contaminants via vector effect, but also affect the transformation process and fate of contaminants via environmental persistent free radicals (EPFRs). The aging processes may enhance the interaction between MPs and co-existed contaminants. Thus, it is of great significance to review the aging mechanism of MPs and the influence of coexisted substances, the formation mechanism of EPFRs, environmental effects of MPs and relevant mechanism. Moreover, microplastic-derived dissolved organic matter (MP-DOM) may also influence the elemental biogeochemical cycles and the relevant environmental processes. However, the environmental implications of MP-DOM are rarely outlined. Finally, the knowledge gaps on environmental effects of MPs were proposed.

Significant regional disparities in riverine microplastics

Research on riverine microplastics has gradually increased, highlighting an area for further exploration: the lack of extensive, large-scale regional variations analysis due to methodological and spatiotemporal limitations. Herein, we constructed and applied a comprehensive framework for synthesizing and analyzing literature data on riverine microplastics to enable comparative research on the regional variations on a large scale. Research results showed that in 76 rivers primarily located in Asia, Europe, and North America, the microplastic abundance of surface water in Asian rivers was three times higher than that in Euro-America rivers, while sediment in Euro-American rivers was five times more microplastics than Asia rivers, indicating significant regional variations (p < 0.001). Additionally, based on the income levels of countries, rivers in lower-middle and upper-middle income countries had significantly (p < 0.001) higher abundance of microplastics in surface water compared to high-income countries, while the opposite was true for sediment. This phenomenon was preliminarily attributed to varying levels of urbanization across countries. Our proposed framework for synthesizing and analyzing microplastic literature data provides a holistic understanding of microplastic disparities in the environment, and can facilitate broader discussions on management and mitigation strategies.

Persistent Luminescence Nanoplatform for Autofluorescence-Free Tracking of Submicrometer Plastic Particles in Plant

The uptake of plastic particles by plants and their transport through the food chain make great risks to biota and human health. Therefore, it is important to trace plastic particles in the plant. Traditional fluorescence imaging in plants usually suffers significant autofluorescence background. Here, we report a persistent luminescence nanoplatform for autofluorescence-free imaging and quantitation of submicrometer plastic particles in plant. The nanoplatform was fabricated by doping persistent luminescence nanoparticles (PLNPs) onto polystyrene (PS) nanoparticles. Cr3+-doped zinc gallate PLNP was employed as the dopant for autofluorescence-free imaging due to its persistent luminescence nature. In addition, the Ga element in PLNP was used as a proxy to quantify the PS in the plant by inductively coupled plasma mass spectrometry (ICP-MS). Thus, the developed nanoplatform allows not only dual-mode autofluorescence-free imaging (persistent luminescence and laser-ablation ICP-MS) but also ICP-MS quantitation for tracking PS in plant. Application of this nanoplatform in a typical plant model Arabidopsis thaliana revealed that PS mainly distributed in the root (>99.45%) and translocated very limited (<0.55%) to the shoot. The developed nanoplatform has great potential for quantitative tracing of submicrometer plastic particles to investigate the environmental process and impact of plastic particles.

Microplastic accumulation in groundwater: Data-scaled insights and future research

Given that microplastics (MPs) in groundwater have been concerned for risks to humans and ecosystems with increased publications, a Contrasting Analysis of Scales (CAS) approach is developed by this study to synthesize all existing data into a hierarchical understanding of MP accumulation in groundwater. Within the full data of 386 compiled samples, the median abundance of MPs in Open Groundwater (OG) and Closed Groundwater (CG) were 4.4 and 2.5 items/L respectively, with OG exhibiting a greater diversity of MP colors and larger particle sizes. The different pathways of MP entry (i.e., surface runoff and rock interstices) into OG and CG led to this difference. At the regional scale, median MP abundance in nature reserves and landfills were 17.5 and 13.4 items/L, respectively, all the sampling points showed high pollution load risk. MPs in agricultural areas exhibited a high coefficient of variation (716.7%), and a median abundance of 1.0 items/L. Anthropogenic activities at the regional scale are the drivers behind the differentiation in the morphological characteristics of MPs, where groundwater in residential areas with highly toxic polymers (e.g., polyvinylchloride) deserves prolonged attention. At the local scale, the transport of MPs is controlled by groundwater flow paths, with a higher abundance of MP particles downstream than upstream, and MPs with regular surfaces and lower resistance (e.g., pellets) are more likely to be transported over long distances. From the data-scaled insight this study provides on the accumulation of MPs, future research should be directed towards network-based observation for groundwater-rich regions covered with landfills, residences, and agricultural land.

An Integrative Chemical Recycling Approach for Catalytic Oxidation of Epoxy Resin and in situ Separation of Degraded Products

Although many approaches have been proposed to recycling waste epoxy resin (EP), the separation of mixed degraded products remains a challenge due to their similar structures. To address this, we present a catalytic oxidation strategy that enables mild degradation of EP and in situ separation of degraded products through supramolecular interactions. The oxidative degradation relies on FeIV=O radicals with strong oxidizing properties, which are generated from the electron transfer of FeCl2 with reaction reagents. As the FeIV=O radicals attacked the C-N bonds of EP, EP was broken into fragments rich in active functional groups. Meanwhile, the FeIV=O radicals were reduced to iron ions that can coordinate with the carboxyl groups on the fragments. As a result, the degraded products with different carboxyl content can be effortlessly separated into liquid and solid phase by coordinating with the catalyst. The success of this work lays the foundation for high-value application of degraded products and provides new design ideas for recycling waste plastics with complex compositions.

Aging increases the particulate- and leachate-induced toxicity of tire wear particles to microalgae

The toxic effects of tire wear particles (TWPs) on organisms have attracted widespread concerns over the past decade. However, the underlying toxicity mechanism of TWPs, especially aged TWPs to marine microalgae remains poorly understood. This study investigated the physiological and metabolic responses of Phaeodactylum tricornutum to different concentrations of TWPs (Experiment 1), virgin and differently aged TWPs (Experiment 2) as well as their leachates and leached particles (Experiment 3). Results demonstrated that TWPs promoted the growth of microalgae at low concentrations (0.6 and 3 mg L-1) and inhibited their growth at high concentrations (15 and 75 mg L-1). Moreover, aged TWPs induced more profound physiological effects on microalgae than virgin TWPs, including inhibiting microalgae growth, decreasing the content of Chla, promoting photosynthetic efficiency, and causing oxidative damage to algal cells. Untargeted metabolomics analysis confirmed that aged TWPs induced more pronounced metabolic changes than virgin TWPs. This study represented the first to demonstrate that both particulate- and leachate-induced toxicity of TWPs was increased after aging processes, which was confirmed by the changes in the surface morphology of TWPs and enhanced release of additives. Through the significant correlations between the additives and the microalgal metabolites, key additives responsible for the shift of microalgal metabolites were identified. These results broaden the understanding of the toxicity mechanism of aged TWPs to microalgae at the physiological and metabolic levels and appeal for considering the effects of long-term aging on TWP toxicity in risk assessment of TWPs.

Upcycling of polyethylene to gasoline through a self-supplied hydrogen strategy in a layered self-pillared zeolite

Conversion of plastic wastes to valuable carbon resources without using noble metal catalysts or external hydrogen remains a challenging task. Here we report a layered self-pillared zeolite that enables the conversion of polyethylene to gasoline with a remarkable selectivity of 99% and yields of >80% in 4 h at 240 °C. The liquid product is primarily composed of branched alkanes (selectivity of 72%), affording a high research octane number of 88.0 that is comparable to commercial gasoline (86.6). In situ inelastic neutron scattering, small-angle neutron scattering, solid-state nuclear magnetic resonance, X-ray absorption spectroscopy and isotope-labelling experiments reveal that the activation of polyethylene is promoted by the open framework tri-coordinated Al sites of the zeolite, followed by β-scission and isomerization on Brönsted acids sites, accompanied by hydride transfer over open framework tri-coordinated Al sites through a self-supplied hydrogen pathway to yield selectivity to branched alkanes. This study shows the potential of layered zeolite materials in enabling the upcycling of plastic wastes.

Degradation of microplastic in water by advanced oxidation processes

Plastic products have gained global popularity due to their lightweight, excellent ductility, high durability, and portability. However, out of the 8.3 billion tons of plastic waste generated by human activities, 80% of plastic waste is discarded due to improper disposal, and then transformed into microplastic pollution under the combined influence of environmental factors and microorganisms. In this comprehensive study, we present a thorough review of recent advancements in research on the source, distribution, and effect of microplastics. More importantly, we conducted deep research on the catalytic degradation technologies of microplastics in water, including advanced oxidation and photocatalytic technologies, and elaborated on the mechanisms of microplastics degradation in water. Besides, various strategies for mitigating microplastic pollution in aquatic ecosystems are discussed, ranging from policy interventions, the initiative for plastic recycling, the development of efficient catalytic materials, and the integration of multiple technological approaches. This review serves as a valuable resource for addressing the challenge of removing microplastic contaminants from water bodies, offering insights into effective and sustainable solutions.

Informing the Exposure Landscape: The Fate of Microplastics in a Large Pelagic In-Lake Mesocosm Experiment

Understanding microplastic exposure and effects is critical to understanding risk. Here, we used large, in-lake closed-bottom mesocosms to investigate exposure and effects on pelagic freshwater ecosystems. This article provides details about the experimental design and results on the transport of microplastics and exposure to pelagic organisms. Our experiment included three polymers of microplastics (PE, PS, and PET) ranging in density and size. Nominal concentrations ranged from 0 to 29,240 microplastics per liter on a log scale. Mesocosms enclosed natural microbial, phytoplankton, and zooplankton communities and yellow perch (Perca flavescens). We quantified and characterized microplastics in the water column and in components of the food web (biofilm on the walls, zooplankton, and fish). The microplastics in the water stratified vertically according to size and density. After 10 weeks, about 1% of the microplastics added were in the water column, 0.4% attached to biofilm on the walls, 0.01% within zooplankton, and 0.0001% in fish. Visual observations suggest the remaining >98% were in a surface slick and on the bottom. Our study suggests organisms that feed at the surface and in the benthos are likely most at risk, and demonstrates the value of measuring exposure and transport to inform experimental designs and achieve target concentrations in different matrices within toxicity tests.

ROS-dependent degeneration of human neurons induced by environmentally relevant levels of micro- and nanoplastics of diverse shapes and forms

Our study explores the pressing issue of micro- and nanoplastics (MNPs) inhalation and their subsequent penetration into the brain, highlighting a significant environmental health concern. We demonstrate that MNPs can indeed penetrate murine brain, warranting further investigation into their neurotoxic effects in humans. We then proceed to test the impact of MNPs at environmentally relevant concentrations, with focusing on variations in size and shape. Our findings reveal that these MNPs induce oxidative stress, cytotoxicity, and neurodegeneration in human neurons, with cortical neurons being more susceptible than nociceptors. Furthermore, we examine the role of biofilms on MNPs, demonstrating that MNPs can serve as a vehicle for pathogenic biofilms that significantly exacerbate these neurotoxic effects. This sequence of investigations reveals that minimal MNPs accumulation can cause oxidative stress and neurodegeneration in human neurons, significantly risking brain health and highlights the need to understand the neurological consequences of inhaling MNPs. Overall, our developed in vitro testing battery has significance in elucidating the effects of environmental factors and their associated pathological mechanisms in human neurons.

Size dependent ingestion and effects of microplastics on survivability, hematology and intestinal histopathology of juvenile striped catfish (Pangasianodon hypophthalmus)

Microplastic pollution is drastically increasing in aquatic ecosystems and it is assumed that different sizes of microplastics have diverse impacts on the physiology of aquatic organisms. Therefore, this study was intended to examine the ingestion and size specific effects of polyamide microplastic (PA-MP) on different physiological aspects such as growth, feed utilization, survivability, blood parameters and intestinal histopathology of juvenile striped catfish (Pangasianodon hypophthalmus). In a 28-day exposure, the fish were fed with different sized PA-MP with a concentration of 500 mg per kg of feed in order to simulate highly microplastic contaminated environment. Three different treatments were set for this experiment i.e. T1, 25-50 μm (smaller microplastic); T2, 300 μm-2 mm (larger microplastic); T3, (mixed) including a control (C); each had three replicates. The highest ingestion was recorded in the gastrointestinal tract (GIT) of fish exposed to smaller PA-MP treatments (T1 followed by T3). The results also showed compromised weight gain (WG; g), specific growth rate (SGR; %/day) and feed conversion ratio (FCR) with the exposure of PA-MP. Besides, survivability significantly reduced among treatments with the ingestion of smaller sized microplastic and found lowest in T1 (65.0 ± 5.0). In addition, the presence of PA-MP in feed negatively affected the concentration of hemoglobin and blood glucose. Similarly, smaller PA-MP caused most erythrocytic cellular and nuclear abnormalities; found highest in T1 that significantly different from other treatments (p < 0.05). Various histopathological deformities were observed in fish fed with PA-MP incorporated feed. The principal component analysis (PCA) showed that the toxicity and stress imparted by smaller PA-MP affected the survivability and blood parameters where larger PA-MP caused mild to severe abnormalities. Based on eigenvector values, the major abnormalities in intestine included occurrence of epithelium columnar degeneration (ECD: 0.402; PC1), hyperplasia of internal mucosa (HISM: 0.411; PC1), beheading of villi (BV: 0.323; PC1), atrophy of mucosa (AM: 0.322; PC1), tiny vacuoles in apical villi (TV: 0.438. PC2), crypt degeneration (CD: 0.375: PC2) and atrophy of goblet cell (AGC: 0.375; PC2). Therefore, it has been speculated that the size based PA-MP ingestion in the GIT interfered with the digestion and absorption as well as caused deformities that reflected negatively in survivability and hemato-biochemical parameters of juvenile striped catfish.

Paper-based material with hydrophobic and antimicrobial properties: Advanced packaging materials for food applications

The environmental challenges posed by plastic pollution have prompted the exploration of eco-friendly alternatives to disposable plastic packaging and utensils. Paper-based materials, derived from renewable resources such as wood pulp, non-wood pulp (bamboo pulp, straw pulp, reed pulp, etc.), and recycled paper fibers, are distinguished by their recyclability and biodegradability, making them promising substitutes in the field of plastic food packaging. Despite their merits, challenges like porosity, hydrophilicity, limited barrier properties, and a lack of functionality have restricted their packaging potential. To address these constraints, researchers have introduced antimicrobial agents, hydrophobic substances, and other functional components to improve both physical and functional properties. This enhancement has resulted in notable improvements in food preservation outcomes in real-world scenarios. This paper offers a comprehensive review of recent progress in hydrophobic antimicrobial paper-based materials. In addition to outlining the characteristics and functions of commonly used antimicrobial substances in food packaging, it consolidates the current research landscape and preparation techniques for hydrophobic paper. Furthermore, the paper explores the practical applications of hydrophobic antimicrobial paper-based materials in agricultural produce, meat, and seafood, as well as ready-to-eat food packaging. Finally, challenges in production, application, and recycling processes are outlined to ensure safety and efficacy, and prospects for the future development of antimicrobial hydrophobic paper-based materials are discussed. Overall, the emergence of hydrophobic antimicrobial paper-based materials stands out as a robust alternative to plastic food packaging, offering a compelling solution with superior food preservation capabilities. In the future, paper-based materials with antimicrobial and hydrophobic functionalities are expected to further enhance food safety as promising packaging materials.

Closed-loop recycling of sulfur-rich polymers with tunable properties spanning thermoplastics, elastomers, and vitrimers

The development of closed-loop recycling polymers that exhibit excellent performance is of great significance. Sulfur-rich polymers possessing excellent optical, thermal, and mechanical properties are promising candidates for chemical recycling but lack efficient synthetic strategies for achieving diverse structures. Herein, we report a universal synthetic strategy for producing polytrithiocarbonates, a class of sulfur-rich polymers, via the polycondensation of dithiols and dimethyl trithiocarbonate. This strategy has excellent compatibility with a wide range of monomers, including aliphatic, heteroatomic, and aromatic dithiols enabling the synthesis of polytrithiocarbonates with diverse structures. The present synthesis strategy offers a versatile platform for the construction of thermoplastics, elastomers, and vitrimers. Notably, these polytrithiocarbonates can be easily depolymerized via solvolysis into the corresponding monomers, which can be repolymerized to virgin polymers without changing the material properties.

Biodegradable Mineral Plastics

Mineral plastics are a promising class of bio-inspired materials that offer exceptional properties, like self-heal ability, stretchability in the hydrogel state, and high hardness, toughness, transparency, and non-flammability in the dry state along with reversible transformation into the hydrogel by addition of water. This enables easy reshape-ability and recycling like the solubility in mild acids to subsequently form mineral plastics again by base addition. However, current mineral plastics rely on petrochemistry, are hardly biodegradable, and thus persistent in nature. This work presents the next generation of mineral plastics, which are bio-based and biodegradable, making them a promising, new class of polymers for the development of environmentally friendly materials. Physically cross-linked (poly)glutamic-acid (PGlu)-based mineral plastics are synthesized using various alcohol-water mixtures, metal ion ratios and molecular weights. The rheological properties are easily adjusted using these parameters. The general procedure involves addition of equimolar solution of CaCl2 to PGlu in equal volumes followed by addition of iPrOH (iPrOH:H2O = 1:1) under vigorous stirring conditions. The ready biodegradability of PGlu/CaFe mineral plastic is confirmed in this study where the elements N, Ca, and Fe present in it tend to act as additional nutrients, supporting the growth of microorganisms and consequently, promoting the biodegradation process.