A local-to-global emissions inventory of macroplastic pollution

Non-essential use of benzotriazole ultraviolet stabilizers in single-use plastics manufactured in India: An avoidable class of plastic additives

Benzotriazole ultraviolet stabilizers (BUVs) are extensively utilized as additives in various polymeric formulations to protect against harmful UV radiation. Classified as persistent, mobile, and toxic additives, BUVs have attracted the attention of researchers and regulatory bodies worldwide. However, there is limited information on the BUVs content in different plastics. This study investigated the presence of six major BUVs in plastic debris collected from Indian water bodies. Based on the usage, plastic debris was categorized into food contact materials (FCMs), personal care products (PCPs), and household items. Plastic debris made of high-density polyethylene had the highest concentrations of UV-P, followed by UV-327, UV-326, and UV-328. UV-329 was the predominant UV stabilizer detected in the PCP sachet, while UV-320 was not detected in any of the plastic debris analyzed. Leaching experiments showed that plastic debris could serve as a mobile source of BUVs to the surrounding water and pose a low to moderate ecological risk (RQ ≥ 0.1) to planktons. The content of UV stabilizer was highest in FCMs (mean ± SD: 27787.98 ± 2304.14 ng/g), compared to PCPs (mean ± SD: 9115.49 ± 2891.18 ng/g) and household items (mean ± SD: 3215.03 ± 521.92 ng/g). The occurrence of BUVs in short-lived plastics such as FCMs, PCPs sachets and daily household items raises human health concerns, questioning the necessity of adding BUVs in these plastics.

Adsorption-desorption of propyrisulfuron in six typical agricultural soils of China: Kinetics, thermodynamics, influence of 38 environmental factors and its mechanisms

Propyrisulfuron, a novel sulfonylurea herbicide, effectively suppresses intracellular acetolactate synthase activity for weed control, but its adsorption behavior in the soil environment remains unclear. To assess potential agroecosystem risks, the adsorption-desorption behavior and mechanism of propyrisulfuron in six typical agricultural soils of China were investigated using a batch equilibrium method, Density Functional Theory (DFT), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy equipped with Energy Dispersive X-ray (SEM-EDX) techniques. It is indicated that the adsorption-desorption of propyrisulfuron in six soils reached equilibrium at 36 h under the optimum water-to-soil ratio (WSr) of 5:1. Adsorption kinetics followed the quasi-second-order kinetic model, while the Freundlich model best described the adsorption process at equilibrium. The adsorption and desorption were significantly and positively correlated with soil clay content, and 38 environmental factors had varying degrees of influence on its adsorption properties, especially those influenced by microplastics (MPs). Furthermore, the adsorption of propyrisulfuron in six soils was primarily a spontaneous, non-homogeneous, and non-ideal physical process, and special strong forces, such as hydrogen bonding might be involved. Consequently, due to its continuous application, potential persistent residues and pollution may occur in some soils. The investigations systematically reported the adsorption-desorption behavior of propyrisulfuron in various agricultural soils for the first time, providing scientific guidance for environmental risk assessment of groundwater pollution caused by its continuous application in agro-ecosystems.

Unveiling the risk of marine litter and derelict fishing gear in remote coral reefs of the Andaman and Nicobar Islands, North Indian Ocean

An increasing amount of plastic litter and derelict fishing gear in the global oceans poses significant threats to corals and reef-associated marine biota. In this context, an underwater marine litter survey was conducted along the fringing coral reefs in the Andaman and Nicobar Islands- a remote archipelago in the Bay of Bengal, Northern Indian Ocean. The result revealed entanglement and smothering of coral colonies by plastic and derelict fishing gear. The survey recorded an average litter density of 0.42 ± 0.08 items/m2 (range: 0.23 ± 0.02 to 0.71 ± 0.09) and a mean mass of 138.61 ± 42.15 g/m2 (range: 70.17 ± 7.74 to 303.4 ± 2.55). Plastic was the most dominant litter (60.82 %) recorded in the reef environment. Derelict fishing gear made of plastic comprised 33.65 % of the total litter. Plastic Abundance Index (PAI), Hazardous Item Index (HII), and Clean Environment Index (CEI) were used to assess the ecological impact of marine litter. These indices highlighted the significant risks posed by marine litter to the coral reef environment. The finding helps to strengthen the assessment of marine litter in remote islands and underscores the urgent need for improved waste management, stricter regulations on the disposal of fishing gear, and effective removal of derelict fishing gear from the coral reef environments. Present study offers actionable insights for policymakers and stakeholders to prioritize interventions for managing marine litter to safeguard vulnerable coral reef systems.

Distribution and characteristics of Microplastics in leachate and underneath soil of two informal landfills

Microplastics (MPs), an emerging pollutant, have garnered global attention as significant environmental concerns. Landfills are the major sources of MPs. However, research on the distribution and characteristics of MPs in leachate and underneath soil of informal landfills remains limited. This study investigated the abundance, polymer type, size, and morphology of MPs in 6 leachate samples and 18 underneath soil samples at different depths from two informal landfills. The ranges of MPs abundance in leachate and underneath soil from landfills were 4,010-33,213 items/Land 592-870 to 47,819 items/kg, related to the landfilled waste composition. MPs size between 20 and 100 µm accounted for the highest proportion (70 %). The fragmentation coefficient α in the underneath soil was higher than that in the leachate, indicating smaller MPs were more likely to migrate into underneath soil after filtration. The fibrous MPs proportion was below 22 %, while the fragmented MPs was more than 78 %. Large fibrous MPs were detected in the underneath soil in landfill A. Polyethylene Terephthalate (PET), Polyurethane (PU) and Polystyrene (PS) were the predominant MPs polymers types in leachate and underneath soil. Polypropylene (PP) was primarily concentrated in the upper and middle underneath soil layers, and Polyurethane (PU) was predominantly in the middle and lower layers. Principal component analysis (PCA) results indicated that geographical factors significantly influenced the distribution and characteristics of MPs. This study revealed the distribution of MPs in leachate and underneath soil at different depths, providing a valuable reference for the risk assessment of MPs pollution.

Advanced Characterization of Industrial Smoke: Particle Composition and Size Analysis with Single Particle Aerosol Mass Spectrometry and Optimized Machine Learning

With the acceleration of industrialization, industrial smoke particles containing complex chemical compositions and varying particle sizes pose a serious threat to the environment and human health. As a powerful tool for aerosol measurement, mass spectrometry can effectively analyze particulate matter. However, due to the high dimensionality and complexity of mass spectrometry data, research on the relationship between particle size and composition remains very limited. To address this gap, this study innovatively combines single particle aerosol mass spectrometry (SPAMS) with optimized machine learning, achieving for the first time the precise prediction of smoke particle size based on mass spectrometry data. Nonlinear dimensionality reduction of mass spectrometry data was performed using kernel principal component analysis (KPCA) to extract key features. Combined with random forest (RF) for prediction, the R2 of the test set reached 0.843 after optimization. Additionally, to address the issue of imbalanced sample distribution, a systematic stratified random sampling algorithm (SSRSA) was developed, significantly enhancing the model's generalization ability and stability during training and testing. This study also simulated a soldering scenario to analyze lead (Pb) isotope abundances and particle size distributions in smoke at different soldering temperatures. Results indicate a significant correlation between the abundance of lead isotopes and the soldering temperature. Additionally, as the soldering temperature increases, the proportion of smaller sized particles increases noticeably. This research provides an innovative approach for precise analysis of industrial smoke particle composition and size, offering critical scientific insights for health risk assessment and the development of pollution control strategies.

Microplastics/nanoplastics contribute to aging and age-related diseases: Mitochondrial dysfunction as a crucial role

The pervasive utilization of plastic products has led to a significant escalation in plastic waste accumulation. Concurrently, the implications of emerging pollutants such as microplastics (MPs) and nanoplastics (NPs) on human health are increasingly being acknowledged. Recent research has demonstrated that MPs/NPs may contribute to the onset of human aging and age-related diseases. Additionally, MPs/NPs have the potential to induce mitochondrial damage, resulting in mitochondrial dysfunction. Mitochondrial dysfunction is widely recognized as a hallmark of aging; thus, it is necessary to elucidate the relationship between them. In this article, we first elucidate the distribution of MPs/NPs in various environmental media, their pathways into the human body, and their subsequent distribution within human tissues and organs. Subsequently, we examine the interplay between MPs/NPs, mitochondrial dysfunction, and the aging process. We aspire that this article will enhance awareness regarding the toxicity of MPs/NPs while also offering a theoretical framework to support the development of improved regulatory policies in the future.

Marine plastic exposure triggers rapid recruitment of plastic-degrading bacteria and accelerates polymer-specific transformations

Plastic pollution in marine ecosystems is a growing concern, yet the degradation behavior of different plastic types and their interactions with microbial communities remain poorly understood. This study investigated the degradation kinetics and microbial colonization of four widely used plastic materials, surgical masks (most made of PP), PET bottles, PS foam, and PP cups, over 40 days of seawater exposure in the Central Atlantic of Morocco. Mass loss measurement revealed distinct degradation patterns, with PS foam showing the highest mass loss (13 %), followed by PET bottles (5 %), likely due to environmental stressors that promote mechanical fragmentation. Surgical masks and PP cups exhibited minimal degradation, retaining nearly all their original mass, as well as limited extent of biodegradation. Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD) analyses showed the formation of oxidative functional groups on PP cups and significant structural changes in PS foam and PET, particularly in their crystalline structures, correlating with their higher mass reduction rates. SEM/EDX biofilm imaging confirmed extensive microbial colonization, particularly on PS and PET surfaces. Using 16S rRNA metabarcoding, we identified a striking enrichment of Exiguobacterium, followed by Pseudomonas, Acinetobacter and Bacillus genera, containing reported plastic degrading strains, which were strongly correlated with the accelerated breakdown of plastics. However, its role in accelerating plastic breakdown in this study remains unclear and may warrant further investigation. Co-occurrence network analysis revealed a progressive shift in microbial community structure, evolving from highly interconnected networks at day 0 to more specialized, modular clusters by day 40, dominated by Proteobacteria and Firmicutes. Atomic Absorption Spectrometry (AAS) demonstrated significant heavy metal accumulation on plastic surfaces, potentially influencing microbial colonization and activity. While the observed fragmentation of PS foam and PET highlights the susceptibility of certain plastics to environmental stressors, this study also positions microbial colonization as a potential contributor to plastic surface changes, providing novel insights into the interplay between microbial communities and plastic degradation in marine environments.

Novel insights related to soil microplastic abundance and vegetable microplastic contamination

Despite evidence of the uptake of soil microplastics (MPs) by crops, there is a paucity of knowledge regarding the contamination of vegetables in real-world environments with microplastics. This study establishes a correlation between the presence of microplastics in farmland and the concentration of microplastics in crops. The soil samples were found to contain Polyethylene (PE), polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC). The proportions of PE and PP in the soil were considerable, with values ranging from 35 % to 70.6 % and 19.3 % to 50 %, respectively. The levels of PVC, PS and Polymethyl methacrylate (PMMA) in vegetables ranged from 3.64 to 17.37 μg g-1, 0.67 to 2.45 μg g-1 and 0.02 to 0.27 μg g-1, with Chinese cabbage exhibiting the highest concentration at 19.84 μg g-1. The highest level of PMMA was found in eggplant at 0.27 μg g-1. Vegetables sampled, including aubergine, lettuce and Chinese cabbage, contained more than two types of plastic. A correlation coefficient of 0.579 was observed between microplastics in vegetables and soil. This study provides insight into the contamination of environmental soils and different types of vegetables, and the data serve as a reference point for future studies.

Accessing a Carboxyl-Anhydride Molecular Switch-Mediated Recyclable PECT Through Upcycling End-of-Use PET

Poly(ethylene terephthalate) (PET), with an annual production of exceeding 70 million tons, is mainly utilized in disposable fields and subsequently contribute to severe environmental pollution. Conventional chemical recycling, which typically involves depolymerizing polymer into monomers, is limited due to the intricate recycling process, excess using unrecyclable solvents and low polymer conversion. Inspired by protein's molecular switches, we propose a novel polymer-to-polymer recycling strategy based on polycondensation principles upcycling waste PET to high-value recyclable poly(ethylene-co-1,4-cyclohexanedimethanol terephthalate) derivatives containing molecular switches. Upon deactivating the molecular switch, an acidification reaction occurs within the system, leading to a rapid and controllable reduction in molecular weight due to the imbalance of reactive group. Conversely, activating the molecular switch triggers a ring-closing reaction that detaches acid anhydrides, bringing about equal molar ratio of groups and thereby facilitating an increase in molecular weight. By simply incorporating a molecular switch into condensation products based on melt polycondensation, closed-loop recycling capability is achieved without necessitating excessive organic solvents or complex depolymerization processes. The present study not only presents a novel pathway for end-of-use PET upcycling but also introduces an innovative concept of molecular switching for the closed-loop recyclability of condensation polymers, thereby demonstrating significant potential for large-scale implementation.

Investigation of microplastic pollution index in the urban surface water: A case study in west Godavari district, Andhra Pradesh, India

Microplastics (MPs) are a growing environmental issue because of their widespread prevalence and their long-term effects on ecosystems and human health. Global studies have identified MPs in various aquatic environments, such as lake, rivers, estuaries, wastewater, and oceans. Although most MPs originate from urban surface water sources, the specific intensity, characteristics, and associated risk assessments remain unclear. This study focuses on west Godavari region of India, specifically analyzing MPs in surface water samples Godavari River and two water treatment plants (WTPs). A total of 330 MPs found in the surface water and 121 MPs in theWTP. In surface water, MPs were predominantly blue and transparent fibers, with the majority measuring less than 500 μm in size. Conversely, at the WTP, larger MPs, primarily in blue fiber form and exceeding 3000 μm, were observed. Additionally, μ-Raman spectroscopy analysis identified the presence of various polymers, including PP, PVC, PC, Nylon, and PET, among others. The risks associated with MPs, including their concentration and chemical composition, were assessed across all sample types using various indices such as Contamination Factor (CFi), Pollution Load Index (PLI), Polymer Risk Index (H), Potential Ecological Risk Index (RI), and Estimated Intake (EI) (daily, annually, and lifetime). The risk assessment revealed that the type of polymer poses a greater risk of MP pollution than the concentrations of MPs themselves. These findings provide critical insights into MP contamination patterns and risks, emphasizing the need for targeted mitigation strategies in this region.

Burnt Plastic (Pyroplastic) from the M/V X-Press Pearl Ship Fire and Plastic Spill Contain Compounds That Activate Endocrine and Metabolism-Related Human and Fish Transcription Factors

In May 2021, the M/V X-Press Pearl ship fire disaster led to the largest maritime spill of resin pellets (nurdles) and burnt plastic (pyroplastic). Field samples collected from beaches in Sri Lanka nearest to the ship comprised nurdles and pieces of pyroplastic. Three years later, the toxicity of the spilled material remains unresolved. To begin understanding its potential toxicity, solvent extracts of the nurdles and pyroplastic were screened for their bioactivity by several Attagene FACTORIAL bioassays (TF, NR, and AquaTox), which measured the activity of a combined 70 human transcription factor response elements and nuclear receptors and 6 to 7 nuclear receptors for each of three phylogenetically distinct fish species. Extracts of the pyroplastics robustly activated end points for the human aryl hydrocarbon receptor (AhR), estrogen receptor (ER), pregnane X receptor (PXR), peroxisome proliferator-activated receptor (PPAR), retinoid X receptor (RXR), and oxidative stress (NRF2) and had the potential for activation of several others. The bioactivity profile of the pyroplastics was most similar (similarity score = 0.96) to that of probable human carcinogens benzo[b]fluoranthene and benzo[k]fluoranthene despite the extracts being a complex mixture of thousands of compounds. The activity diminished only slightly for extracts of pyroplastic collected eight months after the spill. The AquaTox FACTORIAL bioassay measured the activation of ERα, ERβ, androgen receptor (AR), PPARα, PPARγ, and RXRβ for human, zebrafish (Danio rerio), Japanese medaka (Oryzias latipes), and rainbow trout (Oncorhynchus mykiss), revealing species-specific sensitivities to the chemicals associated with the pyroplastics. These findings provide needed information to guide long-term monitoring efforts, make hazard assessments of the spilled material, and direct further research on pyroplastic, an emerging global contaminant.

Inventories of plastic pollution sources, flows and hotspots as a baseline for national action plans: The experience of Mexico

This article explores the development of Mexico's National Inventory of Plastic Pollution Sources (NIPPS), designed to establish a baseline for the country's National Action Plan. The study employed a multifaceted approach, combining material flow analysis tools, literature reviews, and stakeholder workshops. This methodology successfully identified critical leakage points within the waste management system, such as deficiencies in collection and the prevalence of uncontrolled disposal sites. It also recognized priority geographic regions and fostered engagement with relevant stakeholders. However, a comprehensive assessment was hampered by data limitations, including a lack of information on waste composition, inconsistent recycling data, and the use of varied methodologies in field studies of plastic pollution. By highlighting the strengths and limitations of the process, this article underscores the critical role of standardized data collection and analysis in creating robust national plastic pollution inventories. Such inventories serve as a cornerstone for effective National Action Plans and contribute significantly to broader efforts tackling the global plastic pollution crisis. The valuable lessons from Mexico's experience offer insights for other countries facing similar challenges.

Biotechnology for the degradation and upcycling of traditional plastics

Traditional plastics, predominantly derived from petrochemicals, are extensively utilized in modern industry and daily life. However, inadequate management and disposal practices have resulted in widespread environmental contamination, with polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, and polystyrene being the most prevalent pollutants. Biological methods for plastic degradation have garnered significant attention due to their cost-effectiveness and potential for resource recovery, positioning them as promising strategies for sustainable plastic waste management. While polyethylene terephthalate, characterized by its relatively less stable C-O bonds, has been extensively studied and demonstrates significant potential for biodegradation. In contrast, the biodegradation of other plastics remains a significant challenge due to the inherent stability of their C-C backbone structures. This review comprehensively examines the state-of-the-art biotechnology for treating these traditional plastics, focusing on: (1) the roles of specific microorganisms and enzymes, their taxonomic classifications, and the metabolic pathways involved in plastic biodegradation; and (2) a proposed two-stage hybrid approach integrating physicochemical and biological processes to enhance the biodegradation or upcycling of these traditional plastics. Additionally, the review highlights the critical role of multi-omics approaches and tailored strategies in enhancing the efficiency of plastic biodegradation while examining the impact of plastic molecular structures and additives on their degradation potential. It also addresses key challenges and delineates future research directions to foster the development of innovative biological methods for the effective and sustainable management of plastic waste.

Pathways to reduce global plastic waste mismanagement and greenhouse gas emissions by 2050

Plastic production and plastic pollution have a negative effect on our environment, environmental justice, and climate change. Using detailed global and regional plastics datasets coupled with socioeconomic data, we employ machine learning to predict that, without intervention, annual mismanaged plastic waste will nearly double to 121 million metric tonnes (Mt) [100 to 139 Mt 95% confidence interval] by 2050. Annual greenhouse gas emissions from the plastic system are projected to grow by 37% to 3.35 billion tonnes CO2 equivalent (3.09 to 3.54) over the same period. The United Nations plastic pollution treaty presents an opportunity to reshape these outcomes. We simulate eight candidate treaty policies and find that just four could together reduce mismanaged plastic waste by 91% (86 to 98%) and gross plastic-related greenhouse gas emissions by one-third.

Global patterns of lake microplastic pollution: Insights from regional human development levels

Microplastics have emerged as a pervasive pollutant across various environmental media. Nevertheless, our understanding of their occurrence, sources, and drivers in global lakes still needs to be completed due to limited data. This study compiled data from 117 studies (2016-May 2024) on microplastic contamination in lake surface water and sediment, encompassing surface water samples in 351 lakes and lake sediment samples in 200 lakes across 43 countries. Using meta-analysis and statistical methods, the study reveals significant regional variability in microplastic pollution, with concentrations ranging from 0.09 to 130,000 items/m3 in surface water and from 5.41 to 18,100 items/kg in sediment. Most microplastics were under 1 mm in particle size, accounting for approximately 79 % of lake surface water and 76 % of sediment. Transparent and blue microplastics were the most common, constituting 34 % and 21 % of lake surface water and 28 % and 18 % of sediment, respectively. Fibers were the dominant shape, representing 47 % of lake surface water and 48 % of sediment. The primary identified polymer types were polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). Countries like India, Pakistan, and China had higher contamination levels. Positive correlations were found between microplastic abundance in surface water and factors like human footprint index (r = 0.29, p < 0.01), precipitation (r = 0.21, p < 0.05), and net surface solar radiation (r = 0.43, p < 0.001). In contrast, negative correlations were observed with the human development index (r = -0.61, p < 0.01) and wind speed (r = -0.42, p < 0.001). In sediment, microplastics abundance correlated positively with the human footprint index (r = 0.45, p < 0.001). This study underscores the variability in microplastic pollution in global lakes and the role of human activities and environmental factors, offering a valuable reference for future research.