Microplastics as an emerging threat to terrestrial ecosystems

Study on the degradation efficiency and mechanism of polystyrene microplastics by five kinds of edible fungi

The harm caused by microplastics to the environment and human body has become a hot issue, and screening for microorganisms that potentially degrade microplastics is urgently needed. This study is the first to use Auricularia auricula, Pleurotus ostreatus, Ganoderma lucidum, Pleurotus pulmonarius and Pleurotus cornucopiae to degrade PS-MPs. After 50 d of degradation, the average degradation rate was approximately 7.494 %, with the highest degradation rate of Pleurotus ostreatus being 16.17 ± 8.87 %. In addition, the ability of five edible fungi to degrade PS-MPs was confirmed through characterization methods such as scanning electron microscopy and Fourier transform infrared spectroscopy. Finally, for the first time, through the transcriptome and proteome, the genes Cluster-409.10597, Cluster-409.502, and Cluster-409.6781, along with other genes involved in the degradation of PS-MPs in Pleurotus ostreatus, were identified as Extradiol ring-cleavage dioxygenases, Acyl transferase/acyl hydrolase/lysophospholipase, and other enzymes. Additionally, the Ascorbate and Peroxisomes metabolic pathways, which play a role in aldarate metabolism, were also identified. This study is the first multiomic joint analysis of the degradation mechanism of Pleurotus ostreatus, laying a theoretical foundation for a more comprehensive understanding of the degradation of PS-MPs by edible fungi and broadening the directions for the application of edible fungal resources as engineered fungi.

Dynamic responses of soil microbial communities to long-term co-contamination with PBAT and cadmium

The co-contamination of plastics and heavy metals poses novel challenges to agricultural soil ecosystems. However, research into the long-term effects of such co-contamination on soil microbial communities remains limited. This study, through a 540-day incubation experiment, investigated the impacts of poly(butylene adipate-co-terephthalate) (PBAT) and cadmium (Cd) co-contamination on the structure and function of soil microbial communities. The findings revealed that co-contamination significantly altered soil nitrate and ammonium nitrogen levels. Furthermore, the co-contamination continuously and significantly reduced bacterial diversity, producing a more pronounced negative impact compared to single pollution. Key microbial groups such as Proteobacteria, acting as core microorganisms, were significantly enriched under co-contamination conditions, with their relative abundance increasing significantly by 40.0 %. This indicates their potential role in plastic degradation and heavy metal resistance. In addition, the co-contamination also drove the shift of bacterial and fungal community assembly from deterministic processes to stochastic processes. These insights not only fill the research gap regarding the effects of long-term co-contamination on soil microorganisms but also provide a scientific foundation for the development of targeted soil management and remediation strategies, especially in regions where plastic and heavy metal pollution coexist.

Machine learning-driven analysis of soil microplastic distribution in the Bang Pakong Watershed, Thailand

Microplastics (MPs) have emerged as a pervasive environmental pollutant due to their persistence and global distribution. However, MPs relationships with covariables remain largely unexplored. This study investigates factors influencing MPs occurrence and distribution in the Bang Pakong Watershed, using 40 soil samples across various land-use types and assess machine learning for their spatial distribution. Samples were sorted into three sizes: 1.2 μm-500 μm, 500 μm-1 mm, and 1-2 mm and analyzed using zinc chloride (ZnCl2) density separation, hydrogen peroxide (H2O2) digestion, and Fourier transform infrared spectroscopy (FTIR) for polymer identification. Results reveal a significant MPs presence, averaging 1121 ± 2465.6 items/kg dry soil, with particles <0.5 mm (49 %), fragments (74.2 %), transparent (49 %), and polypropylene (PP) (52 %) predominating. Urban soils contained highest concentrations (67.6 %) at 2331 ± 4114 items/kg, followed by irrigation (555 ± 571), agricultural (552 ± 432), and forest soils (417 ± 365). Predictive modeling incorporated 14 variables, including soil properties and environmental factors. The Random Forest model (RF), optimized for complex non-linear relationships and high data variability, shows higher predictive accuracy (R2 = 0.82), with silt content and distance-to-river as key variables. Spatial distribution analysis, developed on model predictions and inverse distance weighting (IDW), demonstrates a concentration gradient increasing southwestward toward the Bang Pakong River. Flood susceptibility and drainage density analysis correlate with interpolation results, suggesting that these factors influence MPs transport and deposition processes. These results refine MPs management, emphasizing urbanization and hydrological factors as drivers for distribution, necessitating targeted mitigation in high-risk areas.

Potential impacts of polyethylene microplastics and heavy metals on Bidens pilosa L. growth: Shifts in root-associated endophyte microbial communities

This study investigates the impact of polyethylene (PE) microplastics of varying particle sizes and concentrations on the growth of Bidens pilosa L. and its root-associated microbial communities in cadmium (Cd) and lead (Pb) co-contaminated soil. PE microplastics had a significant impact on plant growth. Notably, at the P05-10 level, root length, root weight, and total biomass exhibited the greatest reductions by 48.9 %, 44.1 %, and 45.2 %, respectively. Furthermore, PE microplastics reduced photosynthetic pigment levels and promoted the accumulation of reactive oxygen species, as indicated by a 264.8 % and 57.2 % increase in H2O2 content in roots and leaves. High-throughput sequencing revealed substantial alterations in the composition of bacterial and fungal communities, with stress-resilient taxa such as Actinobacteria, Verrucomicrobiota, and Rhizophagus exhibiting increased relative abundance. Correlation analyses indicated that variations in soil pH and enzymatic activity influenced microbial community structure, which in turn affected plant physiological responses. Functional predictions using PICRUSt2 and BugBase suggested enhanced oxidative stress tolerance, increased secondary metabolite biosynthesis, and a higher prevalence of stress-resistant phenotypes under conditions of elevated PE concentrations and smaller particle sizes. Overall, this study provides novel insights into the potential effects of microplastics on Bidens pilosa L., particularly in its role as a hyperaccumulator, highlighting its capacity for heavy metal uptake under microplastic exposure.

Effects of microplastics on black soil health: A global meta-analysis

Microplastics (MPs) have garnered widespread attention as an emerging global contaminant. However, the impacts of MPs on black soil health remain unclear. A meta-analysis of 337 cases from 33 studies was conducted to elucidate the effects of MPs on black soil health. The analysis incorporated 35 indicators, including soil properties, soil enzymes, plant growth, soil animal health, and soil microbial diversity. We investigated the effects of MPs properties, such as particle type, size, concentration, and exposure duration, on soil health. Results showed that MPs led to notable increases in SOM, DOC, available nitrogen by 31.84 %, 14.35 %, and 12.45 %, respectively, while decreasing nitrate nitrogen by 12.89 %. In addition, MPs exposure enhanced soil urease activity by 11.24 % but reduced phosphatase activity by 6.62 %. MPs also diminished microbial alpha-diversity, caused oxidative damage in earthworms, and suppressed plant germination rates. Notably, smaller MPs, higher concentrations, longer exposure periods, and conventional MPs have more detrimental effects on soil health. By applying the entropy weight method combined with the analytical hierarchy process, we quantified the overall impact of MPs on black soil health as a 12.09 % decrease. Our findings underscore the risks of persistent MPs pollution to black soil health.

An integrated evaluation of potentially toxic elements and microplastics in the highland soils of the northeastern Qinghai-Tibetan Plateau

As gateways to the scenic Qinghai-Tibetan Plateau (QTP), some underexplored five grassland (GLs) and three farmland (FLs) soil locations of northeastern counties were investigated. Preliminary detection showed that in the grazing and agricultural soils, elemental concentrations (Fe>Zn>Cr>Cu>Pb>Co>As>Cd) were up to 37 and 10 mg/g, but within the China soil standards, except Cd, while microplastics (MPs) abundances were 200-3640 and 280-973 particles/kg, respectively. Polypropylene (PP: 40-55 %) dominated in GLs mostly as fragments, whereas polyethylene (PE: 72-92 %) in FLs as films. Adsorption results demonstrated that potentially toxic elements (PTEs)-MPs' interaction may chiefly depend on their types and speciation in soils, the physiochemical structure of MPs, and surrounding conditions. The integrated two-dimensional risk assessment categorized three of five GLs under Risk Level VI (high pollution), whereas one of three FLs displayed Risk Level III (moderate pollution). Correlation analysis revealed that altitude, organic matter, soil clay content, and precipitation significantly affected PTEs (p ≤ 0.01), whereas MPs were influenced by altitude, soil clay content, precipitation (p ≤ 0.001), and population density (p ≤ 0.05). Comparison with low-land soils globally designated QTP as a vulnerable region to MPs due to the expanding development. Overall, our study provides a data set to understand the pollution scenario of highlands for its targeted management.

Nanoplastic exposure weakens immunocompetence in the burrowing tarantula (Chilobrachys guangxiensis) following pathogen-associated molecular pattern challenges

Nanoplastics (NPs) have emerged as critical environmental contaminants, with growing concerns regarding their potential harm to organisms. Despite this, knowledge remains limited on whether NP exposure diminishes the capacity of organisms to respond to additional environmental stressors. In this study, we evaluated immune function in a burrowing tarantula, Chilobrachys guangxiensis, following NP exposure and subsequent challenges with lipopolysaccharide (LPS) and β-1,3-glucan. The total hemocyte count (THC) and hemolymph encapsulation rate were assessed to determine immune disruption. In addition, transcriptomic analyses were conducted to elucidate the mechanisms involved after both primary and secondary exposures. Results indicated that prolonged NP exposure did not cause significant changes in immunocompetence in C. guangxiensis. However, upon secondary exposure to LPS or β-1,3-glucan, individuals pre-exposed to NPs displayed significant changes in THC and impaired encapsulation capacity. Gene expression profiling based on quantitative real-time PCR revealed that LPS and β-1,3-glucan elicited varying immune responses and distinct gene expression profiles in NP-exposed C. guangxiensis. These findings suggest that NP exposure weakens immunocompetence in C. guangxiensis. This study provides comprehensive insights into the immune responses triggered by different pathogen-associated molecular patterns in NP-exposed C. guangxiensis, offering a novel perspective on the complex immunotoxicological effects of NP pollution.

Microplastics accumulate in all major organs of the mediterranean loggerhead sea turtle (Caretta caretta)

Microplastics (MPs) are a pervasive marine environmental pollutant, posing a serious threat to marine ecosystems and organisms at all trophic levels. Plastic ingestion is well documented in marine turtles, and loggerhead sea turtles (Caretta caretta) have been identified as an indicator species to monitor MP pollution globally. Our understanding of the translocation and bioaccumulation potential of MPs beyond the gastrointestinal tract is, however, limited. Here we demonstrate that MP translocation occurs in these marine reptiles and present a comprehensive analysis of MP accumulation in body tissues of 10 stranded Mediterranean loggerhead turtles including the kidney, liver, spleen, heart, skeletal muscle, subcutaneous fat, stomach, intestine, and reproductive organs. Foreign microparticles were identified in 98.8 % of all samples (∼70 % being MPs) and were significantly concentrated in the reproductive organs followed by the heart. Raman spectroscopy revealed that polypropylene, cotton fibres, and polyethylene were the most common microparticle types, and optical photothermal infrared (O-PTIR) spectroscopy provided direct visualisation of cotton microfibres embedded in loggerhead heart tissue. Future studies should determine the biological impact of MP bioaccumulation in sea turtle organs, to fully appreciate the impacts of these anthropogenic pollutants on protected and vulnerable populations worldwide.

Exploring the toxicology, socio-ecological impacts and biodegradation of microplastics in Africa: Potentials for resource conservation

Achieving upcycling and circularity in the microplastic economy predominantly depends on collecting and sorting plastic waste from the source to the end-user for resource conservation. Microplastics, whether from packaging or non-packaging materials, pose a significant environmental challenge as they are often not prioritized for collection or recycling initiatives. The presence of additives impedes the quality of plastic recyclates and the persistence of microplastics as shredded resultants remain a threat to the aquatic and terrestrial ecosystem and its biodiversity. Despite the increasing global research on microplastics, the success of plastic and microplastic waste management in Africa is yet to be fully attained. Considering the improper disposal, limited recycling and upcycling intervention, lack of policy, and strict laws against plastic waste management defaulters, the ecosystems in Africa remain immensely impacted by several socio-ecological factors leading to the loss of aquatic organisms through reducing fertility and increasing stress. As a ripple consequence, the disruption of economic activities, toxic effects on animal/human health, and climate crisis are among their impact. This review therefore provides comprehensive detail of microplastic production and challenges in Africa, the toxicology concerns, socio-ecological issues associated with microplastic waste management, and insight into approaches to mitigate plastic pollution through recycling, upcycling, bioprocessing and their biodegradation with social insects and microorganisms which may form the basis for adoption by policymakers and researchers, thereby minimizing the consequences of plastic pollution in Africa.

Polymer waste and pollution in oral healthcare clinics: a systematic review

BACKGROUND

Modern oral healthcare extensively uses polymer items and devices derived from various monomeric compounds. These materials are essential for personal protective equipment, infection barriers, packaging, and intraoral devices. The COVID-19 pandemic has led to an increased reliance on single-use polymer items, causing supply chain disruptions and higher costs. This systematic review explores the extent of polymer waste and pollution generated in oral healthcare clinics.

MATERIALS AND METHODS

A systematic review protocol was registered with PROSPERO and was formatted according to PRISMA guidelines and SWiM recommendations. Eligibility criteria included studies that provided quantified estimates of polymer waste or pollution in air or wastewater from oral healthcare clinics. Comprehensive electronic searches were conducted across several bibliometric databases, followed by data extraction and risk of bias assessments performed by two independent reviewers.

RESULTS

A total of thirty studies were included in the review. Sixteen papers reported on waste audits that detailed polymer waste data, while eight studies focused on pollution caused by polymer nano- and microparticles in clinical settings. Additionally, six experimental studies investigated potential leakage of monomeric eluates or polymer particles from landfill waste. There was significant variation in the amount of polymer waste generated per patient, ranging from 81 to 384 g per operatory room per day. On-site sampling revealed the presence of polymer nano- and microparticles in the clinic air, which was influenced by dental procedures and the equipment used.

CONCLUSIONS

This review highlights critical knowledge gaps about polymer waste and pollution in oral healthcare clinics. The variability of study designs limited the feasibility of meta-analysis. Current evidence indicates substantial polymer waste generation, particularly from single-use items, as well as potential environmental impacts from monomeric eluates and polymer microparticles. Future research should focus on sustainable polymer waste management solutions to reduce environmental pollution in oral healthcare settings.

Spatiotemporal evolution of small microplastics in agricultural soils from long-term pig manure application

Long-term application of organic fertilizers serves as a nutrient source in agriculture, yet the contamination of these materials with small microplastics (sMPs, 20-500 μm) remains poorly understood. Research on the accumulation and morphological transformation of sMPs in soils under extended fertilization regimes is currently scarce. This study employed Laser Direct Infrared (LDIR) Spectroscopy to quantify and characterize sMPs in soils subjected to four fertilization regimes: no fertilizer (CK), pig manure (M), nitrogen-phosphorus-potassium (NPK) fertilizer, and a combination of NPK and pig manure (MNPK). Temporal and spatial dynamics of sMPs were assessed across treatments with prolonged organic input. A progressive increase in both the abundance and type of sMPs was detected in pig manure, reaching 21,376 ± 1008 items kg-1 in 2023-an increase of 180 % compared to 1979.The initial soil sMPs concentrations in 1979 were approximately 3000 items kg-1; after 44 years, levels in M and MNPK treatments reached 7183 ± 568 items kg-1 and 5557 ± 329 items kg-1, respectively. Soils receiving pig manure consistently exhibited higher sMPs concentrations than untreated controls. The relatively elevated levels of sMPs suggest in-situ degradation of larger MPs. Except in the CK treatment, sMPs abundance increased with soil depth. Across all fertilization types, particles within the 30-100 μm range comprised over 46 % of total sMPs, indicating a consistent size distribution. The polymer types and composition in pig manure-amended soils mirrored those identified in the manure itself. These results demonstrate that long-term pig manure application markedly elevates soil sMPs concentrations, increasing the potential for sMPs contamination in agricultural systems.

The impact of polyvinyl chloride microplastics on carbon and nitrogen cycling in peat-forming environments: relevance of the filler additive calcium carbonate (CaCO3)

Peat-forming wetlands (PFW) are crucial in the global C-cycle, yet they are increasingly threatened by various anthropogenic pressures, including microplastic (MP) pollution. We investigate the impacts of polyvinyl chloride (PVC) and its additive, calcium carbonate (CaCO3) on organic matter (OM) degradation in PFW. We conducted two experiments: first, by mixing peat soil with increasing concentrations of crushed sanitary PVC-MP (0.3 %, 3 %, and 30 %) and second, by assessing the role of CaCO₃ in modulating these impacts. Our findings revealed significant alterations in peat chemical properties largely mediated by CaCO3 (i.e. increased pH, and Ca2+, Mg2+, K+ concentrations). PVC-MP increased carbon dioxide (CO2) and methane (CH4) production, as well as dissolved organic carbon release. CaCO3 may have enhanced CO2 release through its dissolution and contributed to CH4 production as a C source for a more diverse and active methanogenic community (higher mcrA gene abundance). Shifts in microbial community composition (e.g. reduction of Acidobacteriae and increase in active fermenters, such as Clostridia) and metabolism (higher lignin-like compounds degradation and P-uptake activity but lower activity of labile-C degrading enzymes) also contributed in the C-cycle alterations. PVC-MP enhanced denitrification (narG gene abundance) but reduced relative proportion of the ammonia-oxidizing archaea Nitrososphaeria, leading to inhibition of nitrification. The effects of PVC-MP were concentration-dependent, with CaCO₃ strongly influencing on the C cycle, while its impact on the N cycle was only partial, suggesting potential effect of other additives, such as plasticisers. Overall, our results highlight a significant disruption of microbial processes due to MP pollution, leading to increased greenhouse gas emissions and significant implications on the role of PFW as global C-sinks.

Polyvinyl Chloride and Polypropylene Microplastics Impact Soil Total Antioxidant Capacity and Exoenzyme Secretions

Microplastics (MPs), notably polyvinyl chloride (PVC) and polypropylene (PP), are major pollutants in terrestrial and aquatic ecosystems. PVC and PP are the most used polymers for manufacturing plastic goods and therefore constitute bulk of plastic debris which are the major sources of MPs. This study examines the impact of PVC and PP MPs on soil total antioxidant capacity (TAC) and microbial exoenzyme activities. A 0.25% (w/w) MP addition significantly reduced soil TAC and the activities of amylase, invertase, and dehydrogenase over 72 h, while cellulase activity increased. The effects varied by MP type, with molecular docking revealing stronger MP binding affinities to exoenzymes for PP than PVC, particularly with cellulase. The findings indicate MPs reduce soil antioxidants and most exoenzyme activities, except for cellulase.

Biodegradation of Poly(Styrene-Alt-Maleic Anhydride) in Soil and Its Toxic Effects on the Environment

In recent years, synthetic polymers have become integral to modern society, but their improper disposal has led to significant environmental challenges. Therefore, it is of great significance to investigate the environmental impact of polymer waste. Herein, we conducted comprehensive research on the biodegradability of poly(styrene-alt-maleic anhydride) (PSM) when exposed to soil and microbes, as well as its toxic effects on soybean seedlings and Eisenia fetida. The biodegradation process of PSM was thoroughly evaluated using respirometry tests, Fourier transform infrared spectroscopy, gel permeation chromatography, weight loss analysis, and bacterial reproduction tests. After 90 days of incubation in soil, the mineralization ratio of PSM reached 15%, and the weight-average molecular weight gradually decreased from 28.0 to 14.5 kg/mol in the first 14 days. Additionally, PSM experienced a 50% degradation by Pseudomonas aeruginosa after 30 days. In terms of phytotoxicity, PSM showed slight effects on the morphology of soybean seedlings while inducing oxidative stress in roots. The toxic effects of PSM on Eisenia fetida were investigated using both filter paper and soil contact methods. The filter paper contact test showed that the LC50 value was above 1000.0 μg/cm2 at 48 h, while the soil contact test indicated an LC50 value of 93.34 g/kg at 7 days. In conclusion, PSM demonstrates excellent biodegradability and low biotoxicity, suggesting great potential for emerging environmental applications.

Microscopic anthropogenic waste ingestion by small terrestrial European passerines: evidence from finch and tit families

Microscopic anthropogenic waste (MAW) has become a major environmental concern worldwide. Our study aimed to assess the accumulation of MAW in the gastrointestinal tracts of nine common European passerine species from finch (Fringillidae) and tit (Paridae) families, and evaluate their suitability for environmental monitoring. We searched for MAW in the birds' stomachs and intestines and identified suspected particles using Raman microspectroscopy. In total, we found 57 MAW particles in 31 out of 149 analyzed individuals, 7 of which were microplastics (polyethylene, polyethylene terephthalate, polystyrene), 1 was identified as carbon nanotube, while 49 were cellulosic-based (cotton, cellulose, rayon, viscose). The generalized linear mixed models identified bird family and time in season as significant predictors of MAW ingestion. Finches ingested more MAW than tits, and higher ingestion rates were observed during the non-breeding period. Other predictors, including bird sex, age, gastrointestinal tract section, and site, showed varying but non-significant effects. As predicted, the studied species exhibited a lower ingestion rate of MAW compared to terrestrial birds studied so far, possibly due to their diet and feeding behavior. Given that these species are prey for many avian and non-avian predators, they may contribute to the transfer of MAW to higher trophic levels.

PLA Block Polymers: Versatile Materials for a Sustainable Future

Block polymers present an almost endless realm of possibilities to develop functional materials for myriad applications. The established self-assembly of block polymers allows researchers to access properties that are inaccessible in homopolymers. However, there is a need to develop more sustainable options than the current commodity block polymers. Derived from renewable resources and industrially compostable, poly(lactide) (PLA) is at the forefront of technological advancements in sustainable block polymers. Its material properties including high stiffness, relatively high glass transition temperature, and semicrystallinity in isotactic versions lend themselves to many applications, and its ease of synthesis provides a well-established platform for developing high-performance materials. This Perspective highlights recent advancements associated with PLA-containing block polymers, including their syntheses, mesostructural considerations, and mechanical properties, from resilient elastomers to tough plastics. We also give our perspective on the subfield of PLA block polymers, our outlook on the future, and our assessment of exciting developments yet to come.

Tracking the source of microplastics in soil-an exploratory case study in peach orchards from east-central Portugal

In the last 20 years, world plastic production has increased rapidly, reaching 4.00 × 1011 kg in 2022. However, less than 10% was recycled. Moreover, most conventional plastics are persistent and, therefore, remain in the environment long after their release. Although most studies on microplastic contamination focus on a single environmental compartment, an integrated and multicompartment approach is highly recommended considering the multitude of interactions between those compartments. This study addresses this knowledge gap, investigating the presence and potential sources of microplastics (MP) in agricultural soils under typical conditions of the Mediterranean region, characterised by dry summers and relatively moist and mild winters (Csa according to the Köppen-Geiger classification). For this, 19 orchards from east-central Portugal were used as case study sites, and a total of 111 samples were analysed. Soil content in MP was assessed in 3 soil layers (0-5, 5-15 and 15-25 cm). To quantify potential sources to soil, information from farmers was used, and samples from irrigation water, atmospheric deposition and manure were analysed. Optical assessment with the assistance of a stereomicroscope was used for MP quantification. The 0-5 cm soil layer showed a lower content (average of 2.2 particles·g-1) and higher particle sizes (average of 168 µm) than deeper soil layers. The identified sources contributed with 1.02 × 105 particles·m-2·year-1. Irrigation water was the main source, representing 55.9% of the aforementioned input rate encountered for the 3 identified MP sources. Additional knowledge is needed regarding the possible variation in MP content throughout the year and between years and the polymer identification, not only in samples collected from soil but also from its main contamination sources. Furthermore, this study should be extended to other crops and regions as part of broader soil health monitoring.

Effects of polylactic acid microplastics on dissolved organic matter across soil types: Insights into molecular composition

Increasing evidence has highlighted the effects of biodegradable microplastics (MPs) on soil organic matter (SOM), but the role of soil type and incubation time remains unclear. This study investigated the effects of polylactic acid microplastics (PLA-MPs) on the amount and molecular composition of dissolved organic matter (DOM) across three paddy soil types (Ferralsol, Alfisol, and Mollisol) and incubation times, revealing soil-specific patterns in DOM transformation: PLA-MPs reduced DOM content in Ferralsol and Alfisol by 29.3-68.2 mg/kg and 27.3-30.9 mg/kg, respectively, but initially increased it in Mollisol (30 d: 220.9 mg/kg; 60 d: 622.0 mg/kg). Molecular analyses revealed a decrease in DOM component diversity at both 30 and 180 d, potentially due to PLA-MPs stimulating microbial activity and accelerating native SOM decomposition. PLA-MPs promoted the formation of CHO (containing carbon (C), hydrogen (H), and oxygen (O)) compounds, whereas microbes selectively decomposed CHONS (containing C, H, O, nitrogen (N), and sulfur (S)) compounds to meet C and N demands, particularly in Ferralsol and Alfisol. This study enhances the understanding of biodegradable MPs' impact on SOM, emphasizing the role of soil properties.

Synthetic phenolic antioxidant contamination in farmland soils induced by mulching films: Distribution and transformation pathways

The occurrence and distribution of synthetic phenolic antioxidants (SPAs) originating from mulch film in farmland soils, along with their transformation characteristics and pathways, remain largely unknown. This study is the first to investigate nineteen SPAs and four transformation products (TPs) in farmland soils across China. In film-mulching soils, concentrations of SPAs (median, range: 83.6 ng/g, 20.6-863 ng/g) and TPs (46.4 ng/g, 8.36-489 ng/g) were found significantly higher than in nonfilm-mulching soils, suggesting that mulch film is an important SPA source in farmlands. The ecological risk posed by SPAs was considerable, with estimated risk quotients (RQs) reaching up to 14.7. Furthermore, a laboratory soil incubation experiment was conducted on pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate) (Ir1010), a typical SPA with high estimated ecological risk (RQs up to 3.01). The half-life of Ir1010 in unsterilized soil was 6.73 days, much shorter than in sterilized soils, suggesting that soil microbes effectively promoted its transformation rate. Importantly, ten TPs of Ir1010 were identified in soil through nontargeted screening using high-resolution mass spectrometry, indicating aromatic epoxidation, hydroxylation, and hydrolysis as transformation pathways. This study firstly reveals the occurrence SPAs and TPs in farmland soils and suggests their transformation mechanism, highlighting the complex risks posed by these emerging agricultural contaminants.

Ecological risk assessment and ingestion of microplastics in edible finfish and shellfish species collected from tropical mangrove forest, Southeastern India

In the Pichavaram mangroves in Southeast India, this study examines the seasonal trends and consumption of microplastic (MPs) by several fish and shellfish species. Four different seasons viz. summer, pre-monsoon, monsoon, and post-monsoon were used to gather the fish and shellfish samples from Pichavaram Mangrove Forest. The results of the present investigation revealed that MP abundance was higher during the monsoon (45 %), suggesting seasonal runoff and increased plastic pollution during heavy rains as key contributors. We observed microplastics in Liza tade (mullet), with 13.33 MPs/individuals in the summer, 0.77 MPs/individuals in the pre-monsoon, 6.3 MPs/individuals in the monsoon, and 2.67 MPs/individuals in the post-monsoon. A significant proportion (32 %) of MPs were smaller than 1 mm. The fibres were predominated with blue (40 %) and red (13 %). The polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) were the primary polymers, according to μ-Raman spectroscopy. The fish species Liza tade and Etroplus suratensis showed the highest levels of contamination, while the shellfish species Portunus sanguinolentus and Scylla serrata did the same. Comparative global analyses reveal that mangrove ecosystems across different regions exhibit the presence of similar polymer types, but microplastic sources vary greatly from place to place. This work highlights the pervasive nature of MPs, their complex seasonal behavior, and their ecological implications, advocating for targeted mitigation strategies to address MP pollution and its potential risks to marine life and ecosystems.

Mapping marine debris hotspots on Boa Vista Island, Cabo Verde

Coastal ecosystems are under increasing threat, with the accumulation of marine debris-particularly plastics-posing significant ecological risks. Oceanic islands are especially vulnerable due to ocean currents depositing marine debris on their exposed shores. This study presents the first assessment of marine debris accumulation on sandy beaches of Boa Vista Island, Cabo Verde. Using a combination of drone-based aerial imagery and sand sampling, we quantified micro-, meso-, and macro-debris densities across 29 beaches. North- and east-facing beaches of the island showed the highest accumulation of marine debris (>85 % plastics), driven by ocean currents. Mean drone-based densities varied between 5 and 2371 macro-debris items per 100 m of beach length, totalling 23,085 items. As for sand samples, mean densities ranged from 0 to 1639 items/m2, totalling 4272 large microplastics, 1221 mesoplastics and 350 macroplastics. The easternmost beach, Ponta de Roque, alone accounted for 31 % of the total debris recorded across all locations, with sand samples averaging 1639 items/m2 (1453 microplastics larger than 1 mm), and drone-based surveys averaging 68 macro-debris items/100 m2. Fishing-related items comprised ∼24 % of drone-surveyed debris, suggesting input from the Northwest African coast. Plastic fragments predominated, with significant correlations between drone-surveyed macro-plastics and sand-sampled large microplastic densities. Drone surveys effectively identified marine debris hotspots, aligning with ground-based data. This study provides important baseline data for long-term monitoring in the archipelago and offers a transferable methodology for assessing plastic pollution in other island systems.

Degradation and habitat-dependent colonization of plastics in Caribbean coastal waters and sediments by bacterial communities

This study investigates microbial colonization of plastics in Caribbean coastal waters. We deployed five polymer types, on set with a mild UV-pretreatment and one set without UV-pretreatment, for 4.5 months in the water column and sediment at two locations, and analyzed the epiplastic biofilms with 16S rRNA gene sequencing. While a significant influence of location and habitat was apparent, we could not detect notable effects related to polymer type or UV-pretreatment on microbial community composition. Nevertheless, potential plastic and hydrocarbon degraders constituted up to 43 % of sequences from epiplastic biofilms, suggesting an affinity for plastic. Indeed, utilizing 13C-labeled PE and PP, we determined incorporation of plastic-derived carbon into microbial biomass. We measured isotopically labeled fatty acids in incubations with 13C labeled plastics in both water column and sediments, whether virgin or pre-weathered with UV light. The apparent biodegradation of plastic in benthic habitats challenges the perception of marine sediments as a final sink for polyolefins.

Aging of textile-based microfibers in both air and water environments

Textile-based microfibers (MFs) are a predominant source of global microplastics (MPs) pollution. Yet, less is known about the aging of textile-based MFs. This study explored the aging behavior of textile-based polyethylene terephthalate (PET) MFs with white (without pigment) and black (with carbon black as pigment) colors in both air and water environments. Ultraviolet (UV) and plasma aging were carried out to simulate the short- and long-term aging of MFs. Results indicated that white MFs exhibited more pronounced surface changes, formed more -OH bonds, and showed a higher increase in the oxygen-to-carbon(O/C) ratio than black MFs in both air and water environments. For example, in the air environment, the percentage increase of O/C for white MFs was 24.43 %, compared to 16.4 % for black MFs during plasma aging process. Further investigations were conducted to elucidate the mechanisms driving higher degree of aging of white MFs. It was verified that the carbon black in the black MFs could enhance their tensile strength and hardness, thereby countering the aging process. Furthermore, excitation-emission-matrix (EEM) analysis of dissolved organic matter (DOM) released from MFs, combined with the detection of reactive oxygen species (ROS) generated by MFs in the water environment, confirmed that carbon black functioned as an effective anti-aging additive. Its protective role, attributed to UV and plasma shielding and reactive radical-trapping mechanisms, led to higher aging degree in white MFs compared to black MFs. These findings provide insights into predicting the aging behaviors of textile-based MFs with different colors in air and water environments.

Effects of microplastic concentration, composition, and size on Escherichia coli biofilm-associated antimicrobial resistance

Microplastics (MPs) have emerged as a significant environmental pollutant with profound implications for public health, particularly as substrates to facilitate bacterial antimicrobial resistance (AMR). Recently, studies have shown that MPs may accommodate biofilm communities, chemical contaminants, and genetic material containing AMR genes. This study investigated the effects of MP concentration, composition, and size on the development of multidrug resistance in Escherichia coli. Specifically, we exposed E. coli to varying concentrations of different MP types, including polyethylene, polystyrene, and polypropylene, across a range of sizes (3-10, 10-50, and 500 µm). Results indicated that the biofilm cells attached to MPs had elevated multidrug resistance (in E. coli. Notably, MPs exhibited a higher propensity for facilitating biofilm and resistance than control substrates such as glass, likely due to their hydrophobicity, greater adsorption capacities, and surface chemistries. Notably, we found that the bacteria passaged with MPs formed stronger biofilms once the MPs were removed, which was associated with changes in motility. Thus, MPs select cells that are better at forming biofilms, which can lead to biofilm-associated AMR and recalcitrant infections in the environment and healthcare setting. Our study highlights the importance of developing effective strategies to address the challenges posed by MPs.

IMPORTANCE

Antimicrobial resistance (AMR) is one of the world's most pressing global health crises. With the pipeline of antibiotics running dry, it is imperative that mitigation strategies understand the mechanisms that drive the genesis of AMR. One emerging dimension of AMR is the environment. This study highlights the relationship between a widespread environmental pollutant, microplastics (MPs), and the rise of drug-resistant bacteria. While it is known that MPs facilitate resistance through several modes (biofilm formation, plastic adsorption rates, etc.), this study fills the knowledge gap on how different types of MPs are contributing to AMR.

Microplastics in the Amur tiger's habitat: Occurrence, characteristics, and risk assessment

Microplastics (MPs) are emerging environmental pollutants that pose a significant threat to wildlife within forest ecosystems. However, the quantity and types of MPs in wildlife forest habitats remain unclear. This study is the first to assess the distribution of MPs in the Amur tiger habitat of northeast China. Our results showed that MPs were detected in soil, water, atmosphere, forage plants, and ungulate and top predator feces within the forest ecosystem, respectively. The average diameter of all detected MPs was 44.99 ± 34.80μm. The predominant polymers found in the samples were polyamide, polyvinyl chloride, and polyurethane. Certain sample types shared similar MP polymer type distributions, indicating potential links in their sources and transfer pathways. Consequently, these findings provide some new insights on the new pollution problem in Amur tiger forest habitats and prompt us to consider how to control and manage the MPs pollution sources in the tiger conservation.

Widespread microplastic and nanoplastic contamination in the intestines of birds: A case study from Chengdu, China

Widespread pollution of microplastics (MPs) and nanoplastics (NPs) poses significant threats to organisms and human health. However, the extent of MPs and NPs contamination and their ecological risks to wildlife remain underexplored. In this study, we used Laser Direct Infrared (LDIR) spectroscopy to identify and characterize MPs in the intestinal contents of 49 bird species, and Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS) to identify NPs in the intestinal contents of five species. LDIR analysis indicated that chlorinated polyethylene (CPE) and polyvinyl chloride (PVC) were the most prevalent plastics among 32 identified types. MP particle sizes below 100 μm were most abundant, and MPs were predominantly in the form of fragments or pellets. We also found that birds with narrower dietary niche breadth had more MPs. Herbivorous and carnivorous birds had higher MP abundance than omnivorous species, which suggests the capacity of MP accumulation across diet categories. The Polymer Hazard Index (PHI) for MPs revealed that most species sampled were classified at hazard levels III or IV. Py-GC/MS identified four types of NPs in bird intestines, including nylon 66 (PA66), PVC, polyethylene (PE), and polypropylene (PP). This study advances our knowledge of plastic pollution ingested by terrestrial organisms and the risks associated with increased plastic pollution in the environment.

Tiny pollutants, big consequences: investigating the influence of nano- and microplastics on soil properties and plant health with mitigation strategies

The impact of nanoplastics (NPs) and microplastics (MPs) on ecosystems and human health has recently emerged as a significant challenge within the United Nations Agenda 2030, drawing global attention. This paper provides a critical analysis of the influence of plastic particles on plants and soils, with the majority of data collected from recent studies, primarily over the past five years. The absorption and translocation mechanisms of NPs/MPs in plants are first described, followed by an explanation of their effects-especially particles like PE, PS, PVC, PLA, and PES, as well as those contaminated with heavy metals-on plant growth, physiology, germination, oxidative stress, and nutrient uptake. The study also links the characteristics of plastics (size, shape, concentration, type, degradability) to changes in the physical, chemical, and microbial properties of soils. Various mitigation strategies, including physical, chemical, and biological processes, are explored to understand how they address these changes. However, further research, including both laboratory and field investigations, is urgently needed to address knowledge gaps, particularly regarding the long-term effects of MPs, their underlying mechanisms, ecotoxicological impacts, and the complex interactions between MPs and soil properties. This research is crucial for advancing sustainability from various perspectives and should contribute significantly toward achieving sustainable development goals (SDGs).

A high resolution gridded dataset for takeaway packaging waste in China

The rapid growth of the takeaway industry has generated considerable takeaway packaging waste (TPW). Current research focuses on the environmental impacts from takeaway packaging at the regional or city level, which may offer limited implications for localized targeted policymaking. In this study, a high-resolution gridded dataset is provided for annual estimates of TPW in China at a grid resolution of 1 km × 1 km. Seven takeaway packaging categories and their usage probabilities are considered in the estimation, and the results are spatially distributed at the grid scale based on the geographic scope of takeaway delivery. The dataset reveals that a total of 366.66 kt of TPW were generated in China in 2018. The top 10% of grids with the highest TPW generation accounted for 64% of the national TPW. The TPW hotspots are typically located in commercial and residential areas. This dataset could promote effective management of TPW, and support strategies to reduce municipal solid waste in line with the "Zero-waste City" program.

Invisible threats in soil: Microplastic pollution and its effects on soil health and plant growth

Microplastics (MPs) are a significant environmental contaminant that increasingly threaten soil health and crop productivity in agricultural systems. This review explores the origins, migration patterns, and ecological impacts of MPs within soil environments, specifically examining their influence on soil structure, microbial communities, and nutrient cycles essential for plant growth. Despite the progress in understanding Microplastic (MP) pollution, gaps remain in assessing the long-term implications on soil stability, microbial biodiversity, and crop yield. Through bibliometric and synthesis analyses of recent studies, this paper identifies how MPs disrupt soil physical and chemical processes, alter microbial dynamics, and interfere with carbon and nitrogen cycles, resulting in reduced soil fertility and compromised crop health. Key findings reveal that MPs can infiltrate plant root systems, impair water and nutrient uptake, and even accumulate in plant tissues, causing oxidative stress, cellular dysfunction, and yield reduction. This work emphasizes the urgent need for refined environmental risk assessments and sustainable agricultural practices to mitigate MP pollution. This comprehensive synthesis offers a foundational perspective to guide future research and policy efforts in addressing MPs' environmental and agricultural impacts.

Biodegradable microplastics affect tomato (Solanum lycopersicum L.) growth by interfering rhizosphere key phylotypes

Biodegradable microplastics (BMPs), which form as biodegradable plastics degrade in agricultural settings, may influence plant growth and soil health. This study investigates the effects of BMPs on tomato growth and the microbial mechanisms involved. A greenhouse experiment applied BMPs-polyhydroxyalkanoate (PHA), polylactic acid (PLA), poly(butylene succinate-co-butylene adipate) (PBSA), and poly(butylene-adipate-co-terephthalate) (PBAT)-to tomato plants. The study analyzed their effects on plant growth, soil properties, and rhizosphere microbial communities. BMP treatments significantly reduced tomato biomass, height, and chlorophyll content compared to the control. PLA0.1 decreased the chlorophyll a/b ratio, while PLA1 increased it. Elemental analysis showed PLA1 increased phosphorus, calcium, and potassium in leaves, whereas all BMPs reduced nitrogen levels. BMPs also altered soil nitrogen and DOC levels, significantly shifting rhizosphere microbial communities, with a notable increase in Betaproteobacteria abundance. Ecological network analysis revealed that BMPs disrupted key microbial modules linked to plant growth. Beneficial modules positively associated with biomass and nutrient uptake were reduced under BMP treatments, whereas harmful microbial taxa in module 3, associated to poor plant health, were promoted. These shifts suggest that BMPs disrupt microbial ecological relationships critical for optimal plant growth. The findings highlight the potential negative impacts of BMPs on tomato growth through changes in microbial dynamics and soil properties.

Extraction and characterization of microplastics in biomined good earth fractions: assessment of urban and suburban landfill sites, India

The sustainability of biomined landfill sites mainly depends on the profitable valorisation of landfill mined wastes based on the physical and chemical properties of the materials. This study focuses on the extraction, concentration, and characterization of microplastics (MPs) as an emergent pollutant in biomined good earth fractions derived from five landfill sites in West Bengal, India: Baruipur, Dhapa, Madhyamgram, Chandannagar, and Howrah. The concentration of MPs in these samples ranged from 11,500 ± 707.1 to 34,500 ± 7778.2 particles/kg having average sizes 1000-2000 µm. Morphological analysis revealed that fragments, films, and fibers are the common MP types across all samples, with sky, black, and red being the predominant colours. µFTIR analysis identified HDPE and LDPE as the primary polymers in the good earth materials derived from all landfill sites, followed by PP, Cellophane, PVC, PS, EPM, EPS, and PET. Pollution Load Index (PLI), Polymer Hazard Index (PHI) and Potential Ecological Risk Index (PERI) were used to assess the risk of good earth materials. PLI values indicated relatively low pollution load, while elevated PHI values exceeding 1000 were noted in Howrah, Dhapa, and Chandannagar due to the presence of PVC. The study suggests the need for standardized methods to extract and quantify MPs in good earth products from landfill sites and the development of protocols or guidelines for the application of good earth in sustainable development projects.

Detection of microplastics in the feline placenta and fetus

The present study aimed to detect microplastics in feline placentas and fetuses in the early stage of pregnancy. For this study, 8 pregnant queens were evaluated. A standardized protocol for the digestion of biological matter was used, as well as a plastic-free approach for sample collection and manipulation. Microplastics were investigated by means of Raman spectroscopy, with the aim of identifying their composition. Four of eight animals were contaminated, with a total of 19 microplastics detected in both fetal and placental samples. Specifically, fetuses from cats 4 and 7 were contaminated, as were the placentas from cats 5, 6, and 7. This work demonstrates that microplastics can accumulate in feline placentas even at the early stage of pregnancy. Moreover, preliminary results of the presence of microplastics in feline fetuses are shown, suggesting that microplastics can cross the placental barrier.

Exposure to mm-scale microplastic particles does not cause weight loss in two earthworm species belonging to different ecological groups

The aim of this study was to estimate the effect of relatively large (1-5 mm) fragments of high-density polyethylene films on two widespread earthworm species belonging to different ecological groups-endogeic Aporrectodea caliginosa and epigeic Lumbricus rubellus. In a microcosm experiment lasting 8 weeks, we tested the food dilution hypothesis, which suggests that the adverse effect of microplastic on earthworms is caused by the dilution of food by plastic, which has zero energetic value. Both earthworm species ingested plastic particles, and both species were seemingly limited by the availability of food. In particular, the addition of food substrate (aspen litter) to the soil had a significant positive effect on the weight of A. caliginosa. In contrast to our expectations, microplastic at relatively high concentrations (0.3% and 2.3% w/w in the soil for A. caliginosa, and 33% and 48% w/w in the litter for L. rubellus) had no significant effect on earthworm biomass. This suggests that the food dilution effect is not likely to be the main mechanism of the adverse effect of microplastic on earthworms. Our work adds to the growing evidence that in many cases microplastic does not harm soil animals.

Microplastic exposure reduces seed germination in a coastal plant

Plastic contamination presents major environmental threats through its degradation into micro-sized particles that are harmful to a variety of organisms, including plants. Among terrestrial habitats, coastal dunes are likely some of the most plastic-polluted, but very few studies thus far have examined microplastic effects on wild plants native to this habitat. Moreover, current research on microplastics has limited environmental relevancy due to the common use of homogenously shaped un-weathered microplastics in exceeding concentrations. Our research examined the effects of microplastics from biodegradable and non-biodegradable origin, in their pristine (raw) and weathered form, at a concentration of 106 particles per ml, on the native coastal plant Cutandia maritima. We first synthesized engineered microplastics of high environmental relevancy from bulk plastic products. Then, we exposed C. maritima plants to the microplastics in the soil. While no effect was found on the plants following chronic exposure to all microplastic types, weathered plastic reduced seed germination after exposure of the mother plants, suggesting epigenetic modifications might have an effect at the embryo stage. In contrast, direct exposure of microplastics, specifically polylactic acid, facilitated seeds germination. Our results highlight the importance of studying the effects of microplastic on seed germination and raise the ongoing ecological consequences of environmental microplastic coastal contamination, which should be taken into account in regulatory and environmental assessments.

Effects of long-term wastewater irrigation on microplastics pollution in agricultural soil

Microplastic (MP) pollution in agroecosystems is a growing concern with unknown consequences for sustainable agricultural activities. Few studies have revealed MPs in soil as a result of wastewater irrigation, despite the increasing application of wastewater irrigation and inadequacy of conventional wastewater treatment plants in removing microplastics (MPs). In this study, the effect of treated wastewater (TWW) irrigation on MPs accumulation in agricultural soils of Konya City (in Türkiye) and the potential risks on agricultural ecosystem were investigated. For this purpose, 202 soil samples taken from 90 TWW irrigated lands and 11 non-agricultural control lands, at depths of 0-10 cm and 10-20 cm, were analyzed for color, shape, and polymer type. The risk level of MPs pollution was determined by the pollution factor (CF), pollution load index (PLI), and polymer risk index (H). The relationship between some physico-chemical properties of the soil and MPs pollution level was also analyzed. The findings of this study revealed a significant difference (P < 0.0001) in the MP count in the TWW irrigated soils, and control soils. While the average numbers of MPs for control soils were 169 ± 46.8 MPs/kg (100-220 MPs/kg) and 140 ± 44.7 MPs/kg (80-240 MPs/kg) for the 0-10 cm and 10-20 cm soil depths, respectively; 329 ± 139.5 MPs/kg (100-840 MPs/kg) and 295 ± 115.4 MPs/kg (80-660 MPs/kg) were identified for TWW irrigated soil samples taken from the same soil depths. Fiber, film, and fragment type MPs were found to be dominant polymer types in TWW irrigated soil, with 56%, 23%, and 16%, respectively. Transparent colored MPs were predominant. MP decreased from 0-10 cm to 10-20 cm depths. Most of the samples were significantly contaminated with MPs (3 ≤ CF < 6), categorized in hazard category class I (PLI < 10). The findings of this study indicate that TWW irrigation increases the accumulation of MPs in agricultural soils, which poses a higher risk to more fertile soils with higher organic matter, total nitrogen, and available phosphorus content. Hazard index assessments reveal that the soils of Konya, often referred to as the "granary of Türkiye," are at risk of MPs contamination. The findings showed that MPs, a neglected type of pollution for soil, will become an even more important problem with increasing wastewater irrigation.

Microplastic-Induced Alterations in Soil Aggregate-Associated Carbon Stabilization Pathways: Evidence from δ13C Signature Analysis

Microplastics (MPs) are known to affect soil carbon stability in a numerous ways. However, the mechanisms by which they alter the carbon stability within soil aggregates remain unclear . Herein, a one-year field experiment was conducted in an arid agricultural region employing stable isotope techniques to evaluate the soil organic carbon flow in the presence of both persistent (PE, PVC) and biodegradable (PLA, PHA) MPs. PE and PVC reduced the stability of soil aggregates, while PLA and PHA maintained it. Additionally, organic carbon content increased in microaggregates but decreased in small macroaggregates for PE and PVC treatments. By contrast, treatment with PLA and PHA enhanced organic carbon content across aggregates. The δ13C values of PE- and PVC-treated aggregates ranged from -25.34 to -20.85‰, while those of PLA and PHA ranged from -16.29 to -9.26‰. Notably, MPs altered the direction of carbon flow between aggregates, reduced carbon flux, and accelerated carbon emissions. RFP and PLS-PM analyses revealed that persistent MPs affected carbon flow primarily via abiotic factors, whereas biodegradable MPs influenced it via biotic factors. These findings provide insights into the mechanisms by which MPs impact aggregate-associated carbon, highlighting their effects on soil ecosystem services.

Environmental Concentrations of Polystyrene Nanoplastics Induce Low-Dose Tamoxifen Toxicity Through Oxidative Stress in Caenorhabditis elegans

In recent years, significant focus has been placed on the negative impacts of nanoplastics on living organisms. However, nanoplastics at environmental concentrations may interact with drugs, leading to more severe side effects in organisms. This study used Caenorhabditis elegans (C. elegans) to investigate how environmental levels (μg/L) of polystyrene nanoparticles (PS-NPs) influence tamoxifen toxicity and its mechanisms. Combined exposure to tamoxifen and PS-NPs significantly impaired locomotion, pumping, brood size, growth, and induced oxidative stress in both parents and offspring compared to single exposures. DAF-2 mutations conferred resistance, while DAF-16 mutations increased susceptibility. The combined exposure promoted DAF-16::GFP nuclear translocation and decreased SOD-3::GFP and HSP-16.2::GFP fluorescence, indicating toxicity through the DAF-2/DAF-16 IIS pathway. Bacterial metabolism was also linked to the toxic effects, feeding C. elegans metabolically inactivated OP50 significantly reduced the toxicity associated with the combined exposure of PS-NPs and tamoxifen. Additionally, dietary N-acetyl-L-cysteine significantly improved resistance to combined PS-NP and tamoxifen exposure. In summary, this study highlights how long-term exposure to environmental nanoplastic levels can enhance drug side effects, providing new insights into nanoplastics' role in drug interactions.

Driving factors and sources of microplastics in soils in the Yellow River source area

Microplastics (MPs) are widespread in various environments worldwide, they pose a serious threat to ecosystems. As a typical remote area, the Qinghai-Tibetan Plateau (QTP) has a sophisticated road system. However, the contributions of anthropogenic and natural factors to MP accumulation in remote plateau regions remain unclear. Here, we investigated the distribution, driving factors, and main sources of MPs in the source area of Yellow River on the QTP. MPs in soil showed an average abundance of (75.39 ± 49.16) items/kg, which was approximately 1-103 lower than that in the lower sections of Yellow River. Film, transparent color, and polyethylene were the common shapes, colors, and polymers, respectively. Under different land uses, MP abundance was remarkably higher in nonagricultural soils than in farmland. The influencing factors, source analysis on the basis of MP characteristics, and statistical analysis (redundancy analysis and structural equation modeling) showed that MP abundance was influenced by nonagricultural activities (tourism, traffic, and grazing). Utilizing the conditional fragmentation model, we further revealed that MP abundance in the upstream and downstream regions was related to roadside dust (traffic) and atmospheric dust. It was associated with human activities, including plastic packaging waste from tourism and herdsmen, in the midstream region. Moreover, MPs in farmland were related to local sources (fertilizers). These results provide valuable information on MP distribution in headstream areas and thus contribute to controlling potential MP pollution on the QTP.

Effects of naturally aged microplastics on arsenic and cadmium accumulation in lettuce: Insights into rhizosphere microecology

Naturally aged microplastics (NAMPs) are commonly found in farmland soils contaminated with heavy metals (HMs), such as arsenic (As) and cadmium (Cd); yet their combined effects on soil-plant ecosystems remain poorly understood. In this study, we investigated the toxic effects of NAMPs and As-Cd on lettuce, considering the influence of earthworm activity, and examined changes in As-Cd bioavailability in the rhizosphere. Four experimental systems were established: soil-only, soil-lettuce, soil-earthworms, and soil-lettuce-earthworms systems, with four NAMPs concentrations (0, 0.1, 0.5, 1 %). Our results showed that exposure to 0.1 % NAMPs reduced As accumulation in lettuce shoots (0.17-0.25 mg kg-1) and roots (1.13-1.72 mg kg-1), while increasing biomass and enhancing root growth by alleviating toxicity. In contrast, the combined stress of higher NAMPs concentration (0.5 %/1 %) and As-Cd caused a 28.4-58.4 % reduction in root activity, which stimulated low-molecular-weight organic acid (LMWOA) secretion in the rhizosphere, increasing the bioavailability of As and Cd and enhancing their absorption by lettuce. Partial least squares path modeling (PLS-PM) revealed that co-exposure altered LMWOA content, soil enzyme activity, and microbial community stability in the rhizosphere, ultimately influencing the bioavailability and uptake of As and Cd by lettuce.

Smallest microplastics intensify maize yield decline, soil processes and consequent global warming potential

Microplastic pollution seriously affects global agroecosystems, strongly influencing soil processes and crop growth. Microplastics impact could be size-dependent, yet relevant field experiments are scarce. We conducted a field experiment in a soil-maize agroecosystem to assess interactions between microplastic types and sizes. Microplastics were added to soils used for maize cultivation: either polyethylene or polystyrene, of 75, 150, or 300 µm size. Overall, we found that microplastic contamination led to increased soil carbon, nitrogen and biogeochemical cycling. Polyethylene contamination was generally more detrimental than polystyrene. Smallest polyethylene microplastics (75 µm) were associated with two-fold raised CO2 and N2O emissions - hypothetically via raised microbial metabolic rates. Increased net greenhouse gases emissions were calculated to raise soil global warming potential of soils. We infer that MPs-associated emissions arose from altered soil processes. Polyethylene of 75 µm size caused the greatest reduction in soil carbon and nitrogen pools (1-1.5 %), with lesser impacts of larger microplastics. These smallest polyethylene microplastics caused the greatest declines in maize productivity (∼ 2-fold), but had no significant impact on harvest index. Scanning electron microscopy indicated that microplastics were taken up by the roots of maize plants, then also translocated to stems and leaves. These results raise serious concerns for the impact of microplastics pollution on future soil bio-geochemical cycling, food security and climate change. As microplastics will progressively degrade to smaller sizes, the environmental and agricultural impacts of current microplastics contamination of soils could increase over time; exacerbating potential planetary boundary threats.

Investigating the distribution of microplastics in soils from e-waste dismantling sites and their adsorption of heavy metals

Microplastics are characterized by strong hydrophobicity, large specific surface area. In addition to the pollutant they contain, the heavy metals adsorbed on the surface of microplastics can migrate or be transformed with them into the environmental medium, which is potentially harmful to humans. The distribution characteristics of microplastics in contaminated soil at the e-waste dismantling site were studied. The study investigated the adsorption characteristics of polyvinyl chloride (PVC), polypropylene (PP) and acrylonitrile-butadiene-styrene (ABS) on copper (Cu), zinc (Zn) and lead (Pb). It analysed the influence of various factors on the adsorption process of heavy metals, the adsorption law of microplastics on some of the heavy metals in the environment, and the risk of heavy metal release from microplastics to soil. The results showed that ABS and PP were the main microplastics in the contaminated soil. Among them, black, white and transparent microplastics accounted for 89.91%. The shape of microplastics is mainly granular, and microplastics with a particle size of 1-2 mm accounted for the largest proportion. Further studies showed that plastic particles made of ABS, PP and PVC also have the adsorption capacity for different types of heavy metals in soil, and the trends of adsorption capacity are: PP>PVC>ABS. When PP does not reach adsorption equilibrium in the adsorption process, the smaller the particle size and the more added amount, the greater the adsorption capacity. This is because the smaller the particle size of the microplastic is, the more adsorption points it can provide, increasing its ability to adsorb heavy metal ions.

Deep learning-driven behavioral analysis reveals adaptive responses in Drosophila offspring after long-term parental microplastic exposure

Microplastics are widely distributed in the environment and pose potential hazards to organisms. However, our understanding of the transgenerational effects of microplastics on terrestrial organisms remains limited. In this study, we focused on the model organism Drosophila melanogaster. We exposed parental flies to polystyrene microplastics (PS-MPs) continuously and collected offspring larvae at different time points (day 2, day 8, day 14). We then employed deep learning techniques to track and analyze the behavior of the offspring larvae to assess the transgenerational effects of PS-MPs on fruit flies. First, we observed a decline in the mobility of offspring larvae as parental flies aged under non-PS-MP exposure conditions. Second, acute exposure of parental flies to PS-MPs did not result in significant transgenerational effects, but after long-term exposure, offspring larvae showed increased crawling speed and decreased crawling angular velocity, indicating enhanced locomotor ability compared to the control group. This suggests that long-term exposure of parental flies to PS-MPs may help offspring adapt to new environments. Our findings not only support the hypothesis of adaptive parental effects, where parents facing environmental pressure challenges may foster offspring better adapted to the environment, but also provide new insights into the transgenerational effects of PS-MPs on terrestrial organisms.

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.

Nanoplastics: Immune Impact, Detection, and Internalization after Human Blood Exposure by Single-Cell Mass Cytometry

The increasing exposure to nanoplastics (NPs) raises significant concerns for human health, primarily due to their potential bioaccumulative properties. While NPs have recently been detected in human blood, their interactions with specific immune cell subtypes and their impact on immune regulation remain unclear. In this proof-of-concept study, model palladium-doped polystyrene NPs (PS-Pd NPs) are utilized to enable single-cell mass cytometry (CyTOF) detection. The size-dependent impact of carboxylate polystyrene NPs (50-200 nm) is investigated across 15 primary immune cell subpopulations using CyTOF. By taking advantage of Pd-doping for detecting PS-Pd NPs, this work evaluates their impact on human immune-cells at the single-cell level following blood exposure. This work traces PS-Pd NPs in 37 primary immune-cell subpopulations from human blood, quantifying the palladium atom count per cell by CyTOF while simultaneously assessing the impact of PS-Pd NPs on cell viability, functionality, and uptake. These results demonstrate that NPs can interact with, interfere with, and translocate into several immune cell subpopulations after exposure. In vivo distribution experiments in mice further confirmed their accumulation in immune cells within the liver, blood, and spleen, particularly in monocytes, macrophages, and dendritic cells. These findings provide valuable insights into the impact of NPs on human health.

Impact of high-density polyethylene (HDPE) microparticles on soil physical-chemical properties, CO2 emissions, and microbial community in a two-year field trial

Contamination by microplastics (MPs) is a serious problem affecting both aquatic and terrestrial ecosystems, but despite the large number of papers published in recent years, the impact of microplastics (MPs) on soil is still debated. This work aims to evaluate the effects of different amounts (0, 1, 2 % v/v) of high-density polyethylene (HDPE) microparticles (1-0.25 mm in size) on soil properties over time. Specifically, in a field plot experiment lasting about 2 years, treated and control soils were periodically sampled and analysed for their physical (aggregate stability and distribution), chemical (total N, soluble C and N, available P), and soil biochemical (basal respiration, microbial biomass C, enzyme activities, and fatty acid methyl ester - EL-FAME) properties. In addition, CO2 fluxes from soil to atmosphere were measured throughout the experiment. The physical and chemical parameters of the treated soils did not differ significantly from the control soil, whereas specific changes occurred in the biochemical characteristics during the experiment, particularly in the soil treated with the higher dose of MPs. In the early period (21 to 46 days after the treatment), some changes in the microbial community structure were observed for the soil treated with 2 % MPs, suggesting the occurrence of stress conditions for the microbial biomass, likely due to nutrient limitation. After 166 g from the start of the experiment, the 2 % MPs-treated soil showed, other than a lower CO2 flux than the control soil, a reduction of basal respiration together with an increase in actinomycetes and total fungi (both saprophytes and AMF). There was also an increase in C-related enzyme activities one year after treatment with MPs. These latter results suggest that the soil microbial community may be adapting to the new conditions and available energy substrates, which may also indicate the onset of HDPE degradation processes.

Toxicological complexity of microplastics in terrestrial ecosystems

Microplastics (MPs), defined as plastic debris, smaller than <5 mm, are viewed as persistent contaminants that significantly modify terrestrial ecosystems and biodiversity by altering soil microbiota, structure, and functions. This paper summarizes MPs' interactions with various pollutants, including heavy metals and pesticides, also addressing socio-economic impacts, such as reduced agricultural yields and threats to regional fisheries. The study emphasizes the need for an on the basis of waste management model to mitigate these effects, advocating for collaborative efforts among stakeholders. Also, interdisciplinary studies incorporating material sciences, ecology, and environmental policy are essential to confront the challenges of MPs to ecological services. Additionally, the review highlights how MPs can serve as vectors for toxins to damage soil health and species survival. The overview underscores a complex interplay between environmental and socio-economic systems, addressing the urgency of harnessing MPs pollution and protecting ecosystem integrity and sustainability.

Exposure to Polystyrene Microplastic Differentially Affects the Colon and Liver in Adult Male Mice

Microplastics (MPs) have emerged as novel environmental pollutant. Their ubiquity in natural environments and the global dissemination of plastic particles through food and drink have led to the oral ingestion of these particles by all kinds of living organism. In this investigation, male mice were subjected to exposure to 2 μm virgin PS-MPs for 6 weeks. To accomplish this, 36 adult male NMRI mice were gavaged with PS-MPs at concentrations of 0.01, 0.1, and 1 mg/kg body weight. A control group was also accounted for, which received 0.1 mL of distilled water. The results show that the activity of antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) decreased, while the level of malondialdehyde increased in colon and liver. Additionally, findings showed that PS-MPs can disrupt the integrity of the intestinal barrier and inhibit the secretion of intestinal mucus in mice, disrupt mucin secretion, and cause changes in the tissue structure of the colon and liver. Further information regarding the toxicity of MPs in a terrestrial organism was obtained through this study, which assist in the evaluation of the potential health hazards that PS-MPs may pose to living organisms.

Plastics aplenty in paddy lands: incidence of microplastics in Indian rice fields and ecotoxicity on paddy field phytoplankton

Occurrence of microplastics (MP) in natural paddy fields and its impact are less studied. This study reports the abundance of MP in two paddy fields of Kerala, India, cultivating rice crops, 'Pokkali' and 'Uma' crops, which are vital to Kerala's food security and climate resilience. Fourier transform infrared spectroscopy (FTIR) analyses confirmed the presence of polyethylene (PE) and polypropylene (PP) fragments as major MP in the surface water of paddy fields during vegetative (transplantation) and ripening (near harvesting) phases. MP density in the vegetative phase of 'Pokkali' (1370 ± 468.51 fragments/m3) and 'Uma' (1110 ± 304.96 fragments/m3) was thrice more than the ripening phase concentrations (400 ± 196.85 and 370 ± 57.00 fragments/m3, respectively). Subsequently, ecotoxicity of MP and plastic leachates (PL) on phytoplankton that are naturally found in rice fields was examined. Microalga, Chlorococcum sp., and cyanobacterium, Synechococcus sp., were grown in modified BG11 and BG11 media, respectively, and tested with paddy field concentrations for PE-MP and PE-PL. MP bestowed a significant hormetic effect on the specific growth rate of the microalga (121% of the control) whereas the cyanobacterial growth was negatively impacted (70% of the control). Both phytoplankton exhibited a similar response when exposed to PL, but results were neither dose-dependent nor significant. Further, increased catalase activity and compromised superoxide dismutase machinery in the cyanobacterium corroborated the toxic impact on growth (p ≤ 0.05), which indicates reactive oxygen species (ROS) generation in MP-treated groups. ROS generation indicates oxidative stress following MP exposure in the studied phytoplankton perhaps through surface contact or by leaching of toxic intermediates into the medium. The distinctive responses of paddy field phytoplankton to MP and PL stress suggest that MP pollution may enrich certain resilient species over others leading to a possible change in phytoplankton community structure. Pollution load indices suggest that even environmental concentrations of MP and PL may affect the rice productivity as paddy field phytoplankton play a significant role in sustaining and enhancing crop health. Therefore, the presence of MP at alarming concentrations in the paddy fields signifies the emergence of a global environmental and food security concern.

Microplastic effects on soil nitrogen cycling enzymes: A global meta-analysis of environmental and edaphic factors

Microplastic accumulation in soil ecosystems poses significant environmental concerns, potentially impacting nitrogen cycling processes and ecosystem health. This meta-analysis of 147 studies (1138 data points) assessed the impact of microplastics (MPs) on soil nitrogen-acquisition enzymes. We found that MPs exposure significantly increased soil urease (UE) and leucine aminopeptidase activities by 7.6 % and 8.0 %, respectively, while N-acetyl-β-D-glucosaminidase activity was not significantly affected. Biodegradable MPs showed more pronounced effects compared to conventional MPs. Enzyme activities were influenced by MPs properties (e.g., polymer type, size, concentration), experimental conditions (e.g., field or laboratory setting, temperature, nitrogen fertilization), and soil properties (e.g., clay content, pH, organic carbon, total nitrogen). For instance, acidic soils enhanced UE activity, while neutral soils reduced it. These findings emphasize the complex interactions between MPs and soil ecosystems, highlighting the need for context-specific environmental management strategies and policy-making approaches to mitigate the impacts of MPs pollution on soil health.

Pollution risk assessment in sub-basins of an open dump using drones and geographic information systems

The sustainable management of municipal solid waste (MSW) presents a pressing global challenge. This study introduces an innovative methodology for analysing open dumps in Tucumán, Argentina, using unmanned aerial vehicles (UAVs) and DroneDeploy software for data collection, coupled with QGIS for estimating contamination risk at the sub-basin level. By integrating satellite imagery, ground surveys, high-resolution UAV imagery and a multi-criteria decision analysis within geographic information system, we provide a comprehensive overview of dumpsite conditions at one open dump. Commercial drone flights facilitate the rapid and cost-effective creation of digital elevation models and digital terrain models, along with orthomosaic imagery, from which waste footprints are delineated using artificial intelligence to enhance the understanding of geospatial issues. Approaching data layers, such as leachate pools, riverbanks and solar radiation, supports informed decision-making in MSW management through a replicable methodology. Field validation and the inclusion of subsurface and groundwater processes are recommended for future research to improve accuracy and maximize socio-ecological benefits.