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Plastic pollution in river environments has become an emerging global concern. However, the migration of plastic and changes in its properties between river compartments are less understood. This study demonstrates the plastic debris aging and the dynamics between floodplain, surface water, and sediment compartments of the Tuul River, Mongolia. Plastic occurrence is evaluated in terms of their abundance, size, shape, polymer type, and photodegradation in each compartment. Photodegradation stages were calculated using the carbonyl index (CI). Plastic abundance was 5.46 ± 3.53 items m−2 in the floodplain, 155 ± 100.7 items m−3 in the surface water, and 128.4 ± 76.3 items kg−1 in the sediment. Microplastics dominated in the size category in all compartments, while macro- and megaplastics were found only in the floodplain. Polyethylene and polypropylene dominated the surface water and sediment, while polystyrene was the predominant plastic in the floodplain. A positive correlation was found between the distributed polymer types in the surface water and sediment compartments. The similar composition in size and polymer type suggests vertical plastic migration from water to sediment. Although CI values showed that the plastic aging was significantly different between water and sediment (water, 0.61 ± 0.26, and sediment, 0.90 ± 0.68), the dominance of low-density plastics with high CI in the sediment suggests that the aged plastic density changed during the vertical transport in the river system. [ABSTRACT FROM AUTHOR]

Macroplastics are a global threat to the aquatic environment and will degrade into microplastics over time. Its presence in canal causes pollution and inhibits water flow, causing flooding in urban areas; therefore, it is essential to identify and monitor its presence. Addressing knowledge gaps is critical in determining solutions for mitigation purposes. In visual object detection studies, aerial mapping is developed with advanced technology, such as unmanned aerial vehicles (UAV). This research aims to conduct aerial mapping experiments to find the right formula or technical reference for detecting macroplastic waste objects floating on the surface of the canal, including flight altitude, exposure to sunlight, and the influence of season on object detection. Aerial mapping will be done in densely populated urban canals in Southeast Asia, Indonesia, and Makassar City. The aerial mapping survey method will be used, and then the data will be processed in the digitization process and object detection with GIS. The analysis kernel in GIS tools will be used to see the distribution density of macroplastics. The research results show that autoblock occurs at heights of 5m and 10m, but this autoblock can be minimized at a flight height of 15 m. Apart from that, height also affects flight duration. The lower flying height will result in better visual accuracy and better resolution. However, at a height of 15m, macroplastic objects were still detected on a moderate scale. This research successfully distinguished various plastic waste materials, the most found being the soft polyolefin category in plastic bags. Monitoring results detected 321 items of macroplastics in the dry season and 1,163 in the rainy season, or a threefold increase with conditions spread thinly in the dry season. In the rainy season, they gather densely on one side of the canal. [ABSTRACT FROM AUTHOR]

This study investigates plastic litter on two beaches in Malta, Golden Bay and Rivera Beach, with a focus on plastic abundance, characteristics, sources, and the influence of human activity on pollution levels. Conducted in March 2023 during the low-tourist season, 13 sediment samples were collected from a depth of 5 cm using a systematic square sampling method. Plastic litter was quantified and sorted by size, shape, color, and polymer type, and concentrations of potentially toxic elements (PTEs) were measured (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and Fe via ICP-OES). Golden Bay exhibited significantly higher plastic quantities (53.9 ± 4.3 n/m2) compared to Rivera Beach (29.7 ± 4.0 n/m2). Microplastics were dominant on both beaches, with Golden Bay showing a higher proportion (57.0%) than Rivera Beach (50.6%). The plastic litter predominantly consisted of PE (59.6–68.0%) and PP (29.6–38.8%). Golden Bay plastics had PTE concentrations up to 4.9 times higher than those in Rivera Beach, notably for Mn (309.0 μg/g vs. 63.1 μg/g). This research contributes valuable insights into the dynamics of plastic pollution in coastal environments, particularly in areas influenced by tourism. [ABSTRACT FROM AUTHOR]

The diet and feeding behavior of South Polar Skuas (Stercorarius maccormicki) are well studied within the species’ breeding range but are poorly understood on the Haswell Islands. The aim of this study was to determine how South Polar Skuas use available resources during the pre-breeding and breeding periods at the Haswell Archipelago (66°31′ S, 93°01′ E, Davis Sea, Southern Ocean) under conditions of prolonged human activity. I studied pellets, spontaneous regurgitation, and stomach contents of feathered birds to study the diet of skuas and used direct observations of their feeding behavior. South Polar Skuas at the Haswell Islands fed primarily on the Emperor Penguin (Aptenodytes forsteri) colony and on terrestrial resources in the Adélie Penguin (Pygoscelis adeliae) and fulmarine petrel colonies. The dominant prey of skuas were breeding Antarctic penguins. Emperor Penguins and Adélie Penguins make up the bulk of the skuas’ diet in the pre-breeding and breeding periods. Surface feeding at sea was observed in the post-breeding period. In recent decades, kitchen waste supported the skua population. Scavenging (placenta and feces of Weddell seals [Leptonychotes weddellii], frozen eggs, chicks and adults of breeding bird species, kitchen refuse) is the dominant strategy for obtaining food. Adélie Penguin eggs and chicks were the main food items of the South Polar Skuas in the Haswell Archipelago. Skua predation could potentially influence the breeding success of Adélie Penguins and fulmarine petrels, but the extent of the impact is unknown. The impact of the South Polar Skua on Emperor Penguins is negligible because skuas feed mainly on frozen chicks and eggs of the species.

Simple Summary: This work focuses on the diet and feeding ecology of the South Polar Skua, a large gull-like seabird that breeds around Antarctica and winters in the Indian Ocean and Northern Hemisphere. This study presents information from the Haswell Islands off the Antarctic coast in the Davis Sea, where skuas breed near colonies of other seabird species. The composition of the diet of South Polar Skuas included animal (vertebrate and invertebrate organisms), plant, mineral, and anthropogenic components. The diet during the pre-breeding and breeding periods was based on eggs and chicks found in Emperor and Adélie penguin colonies. During the post-breeding period, skuas have been observed feeding at sea. In general, they obtained food by scavenging, but they could also prey on the eggs and chicks of Adélie Penguins and other seabirds. In recent decades, kitchen waste became an additional food resource that supported the skua population. It was found that South Polar Skuas did not influence the breeding success of Emperor Penguins but could potentially influence the breeding success of Adélie Penguins and other seabirds. The diet and feeding behavior of South Polar Skuas (Stercorarius maccormicki) are well studied within the species' breeding range but are poorly understood on the Haswell Islands. The aim of this study was to determine how South Polar Skuas use available resources during the pre-breeding and breeding periods at the Haswell Archipelago (66°31′ S, 93°01′ E, Davis Sea, Southern Ocean) under conditions of prolonged human activity. I studied pellets, spontaneous regurgitation, and stomach contents of feathered birds to study the diet of skuas and used direct observations of their feeding behavior. South Polar Skuas at the Haswell Islands fed primarily on the Emperor Penguin (Aptenodytes forsteri) colony and on terrestrial resources in the Adélie Penguin (Pygoscelis adeliae) and fulmarine petrel colonies. The dominant prey of skuas were breeding Antarctic penguins. Emperor Penguins and Adélie Penguins make up the bulk of the skuas' diet in the pre-breeding and breeding periods. Surface feeding at sea was observed in the post-breeding period. In recent decades, kitchen waste supported the skua population. Scavenging (placenta and feces of Weddell seals [Leptonychotes weddellii], frozen eggs, chicks and adults of breeding bird species, kitchen refuse) is the dominant strategy for obtaining food. Adélie Penguin eggs and chicks were the main food items of the South Polar Skuas in the Haswell Archipelago. Skua predation could potentially influence the breeding success of Adélie Penguins and fulmarine petrels, but the extent of the impact is unknown. The impact of the South Polar Skua on Emperor Penguins is negligible because skuas feed mainly on frozen chicks and eggs of the species. [ABSTRACT FROM AUTHOR]

Background: This review reveals the role of linear economy prevalence and mismanagement practices in plastic pollution of aquatic and terrestrial environments and related knowledge gaps in Romania while outlining downstream and upstream solutions to reduce plastic pollution and adopt circular economy strategies. Thus, the major aim of this study is the investigation of the stage of scientific knowledge concerning all these demands in the Romanian context. Methodology: This work integrates two main approaches: (i) a bibliometric analysis fed by Web of Science and Scopus databases to reveal the current coverage of peer-reviewed literature related to plastic waste in Romania and (ii) a subject-based review to underline the main themes related to plastic waste management, plastic pollution, and mitigating options in Romania in line with circular economy principles. Results: Reducing plastic pollution requires scientific knowledge, multi-sectoral cooperation, and societal awareness. Following this, the topics of plastic waste and plastic pollution appeared to be under-investigated in the literature considering Romania as a case study and concentrated around the 2020 year, emphasizing, in this way, the trendiness of plastic waste concerns and their management in the current research landscape. Our analysis points out that: (i) Romania is facing massive plastic pollution requiring solid improvements in waste management performances; (ii) few peer-reviewed research studies are performed in Romania for both macro and microplastic concerns with unknown pollution levels in most of its geographical regions; (iii) the plastic waste management is still understudied here, while waste statistics are poorly available at local levels; (iv) the perspectives of circular economy transition are still limited, feeding the plastic pollution in the coming years. Conclusions: Several knowledge gaps are identified and must be covered by future research such as (i) adjusting mismanaged plastic waste levels to regional waste management performances and determining littering rates in urban and rural areas to improve the plastic pollution modeling inputs; (ii) examining plastic pollution associated with landfill sites and waste imports; (iii) assessing the sectoral contributions to macro and microplastic pollution of aquatic environments related to municipalities, tourist destinations, agriculture, etc.; (iv) determining retention levels of plastic in river basins and role of riparian vegetation; (v) analyzing microplastics presence in all types of freshwater environments and interlinkage between macroplastic fragmentation and microplastic; (vi) assessing the plastic loads of transboundary rivers related to mismanagement practices; (vii) determining concentrations of microplastics in air, soil, and other land use ecosystems. [ABSTRACT FROM AUTHOR]

Plastic pollution is an important emerging environmental problem with possible impacts on biodiversity and human health. Although the majority of the scholarly attention in this field has been directed to oceans, plastic pollution has not been fully elucidated in freshwater ecosystems. Hence, this study aimed at investigating the spatial distribution and macro- and meso-characteristics of sedimentary plastic waste items along the Zayandeh-Rud River course. 400 types of anthropogenic debris were collected from 21 sampling sites consisting of macroplastic 58.3% (233 items), mesoplastic 18% (72 items), and other waste 23.8% (94 items). Bags (polyethylene), food packs (mainly polypropylene and polystyrene), and bottles (polyethylene terephthalate) were the dominant plastics. The Clean-Coast index was used to determine the river's cleanliness, showing that most parts of the river are clean. The Clean-Coast Index revealed useful implications in evaluating the continuity and success of protective measures such as educational, media, and enforcement actions to reduce river pollution.

Plastic pollution in the hydrosphere ranks among the most pervasive environmental issues since the inception of the plastic industry and its widespread use in our daily lives. Nowadays, numerous countries worldwide suffer from this pollution not only along coastlines but also in deep-sea ecosystems. Our study carried out in the Gulf of Annaba aims to assess the prevalence and spatial distribution of plastic waste. Sampling was conducted at four coastal sites: El Battah, Seybousse, Rizzi Amor, and Ain Achir, both before and after the Covid-19 pandemic. The results reveal varying rates of macro and microplastic contamination, influenced by geographical differences, urban activities, and hydrodynamic factors. Moreover, the proportions of contamination depend on the types of waste. Furthermore, our study showed a clear divergence, particularly in two periods before and after the pandemic. Due to the lockdown, implemented in 2020, there was a marked decrease in the percentage of sediment plastic pollution, attributed to reduced human activity and partial cessation of industrial operations in these areas. [ABSTRACT FROM AUTHOR]

This study is the first report evaluating the microplastic (MP) and macroplastics capture potential of Pontederia crassipes. Total of 3691 (508 microplastic and 3183 macroplastic) particles were extracted from the roots of 12 examined specimens. Mean macroplastic abundance in the roots was found as 265±44 macroplastic/specimen. Majority of the extracted macroplastics were fragment in shape, blue in color. Mean microplastic abundance was found as 42±23 MPs/specimen. Majority of the extracted microplastics were fragment in shape, blue in color and less than 500 µm in size. Results of this preliminary study showed that this species have significant ability to adsorb micro and macroplastics by the roots which makes them perfect employees for integrated floating systems. [ABSTRACT FROM AUTHOR]

Anthropogenic litter (AL), or trash, in urban rivers is abundant, mobile, and shows a wide diversity of types (e.g., plastic, metal, textiles) and input pathways. Previous work suggests AL can be moved along with naturally occurring organic matter (e.g., sediment, leaf litter, and wood) according to particle properties and stream hydrology. Debris dams are key sites of organic matter retention in streams. AL likely accumulates in debris dams; however, measurements of AL dynamics in debris dams and non-debris dam habitats in urban streams are uncommon, as are measurements of AL composition within different zones of debris dam structure. We measured AL density as count (no./m2) and mass (g/m2) in paired debris dam and non-debris dam sites in urban streams in Baltimore, Maryland, USA and Chicago, Illinois, USA. Within debris dams, we recorded AL by 4 zones: 1) overhanging, 2) floating, 3) submerged, and 4) riparian. As expected, there was more AL within debris dams compared with non-debris dam habitats. Across all sites, most AL was composed of plastic materials, but we also noted distinctions in composition. Heavy items, such as ceramic materials, dominated non-debris dam sites, whereas expanded polystyrene and cigarette litter were more common in debris dams. Similarly, there was evidence of AL sorting within debris dams, with distinct composition between the floating (lightweight items) and submerged zones (heavy materials). AL composition in the riparian and overhanging zones showed no differences to one another or to the floating or submerged zones. Overall, AL had patchy distribution in streams and followed well-known processes that drive particle transport. Because debris dams are hot spots of biological activity, accumulation of AL within debris dams may facilitate interaction with stream biota. Improved understanding of the spatial distribution of AL within urban streams is valuable to improve models of AL density and movement at the watershed scale and to inform policies to prevent or remove AL from polluted sites. [ABSTRACT FROM AUTHOR]

The circular economy has been promoted as a solution to plastic pollution, but cities and communities bear the brunt of plastic pollution. The Circularity Assessment Protocol (CAP) is a systems method of collaborative and open data collection for communities to use for decision‐ and policy‐making. The CAP has been utilized in 51 cities in 14 countries and is illustrated here in Metro Manila. Results include identifying manufacturing and parent companies to bring to the table; documenting most (77%) products are in single‐use multi‐layer film packaging; a small, but growing formal refill and reuse system; 10% of to‐go food containers composed of paper‐based alternatives, and a snap‐shot leakage concentration of plastics to the environment that is 1.8%–2.7% of current waste generation. Community narratives emerged from a collaborative workshop and are threaded throughout opportunities identified by the CAP process to inform circularity, future actions, and policy, as a scalable way to create systems change for plastic pollution from the ground up. Plain Language Summary: The Circularity Assessment Protocol, or CAP, is a collaborative framework for communities to collect data on circular materials management, like plastic packaging or food waste. This framework is illustrated for plastic packaging with a local non‐governmental partner in Manila, Philippines. From this framework, local community members help to define opportunities to reduce plastic pollution. Key Points: A Circularity Assessment Protocol framework for cities was developed and applied to Metro ManilaA local trained community partner collected data working with researchers; community members identified opportunities to optimize circularityThis localized framework provides community‐level opportunities to change, and over multiple cities can create a larger systems change [ABSTRACT FROM AUTHOR]

Background This review reveals the role of linear economy prevalence and mismanagement practices in plastic pollution of aquatic and terrestrial environments and related knowledge gaps in Romania while outlining downstream and upstream solutions to reduce plastic pollution and adopt circular economy strategies. Thus, the major aim of this study is the investigation of the stage of scientific knowledge concerning all these demands in the Romanian context. Methodology This work integrates two main approaches: (i) a bibliometric analysis fed by Web of Science and Scopus databases to reveal the current coverage of peer-reviewed literature related to plastic waste in Romania and (ii) a subject-based review to underline the main themes related to plastic waste management, plastic pollution, and mitigating options in Romania in line with circular economy principles. Results Reducing plastic pollution requires scientific knowledge, multi-sectoral cooperation, and societal awareness. Following this, the topics of plastic waste and plastic pollution appeared to be under-investigated in the literature considering Romania as a case study and concentrated around the 2020 year, emphasizing, in this way, the trendiness of plastic waste concerns and their management in the current research landscape. Our analysis points out that: (i) Romania is facing massive plastic pollution requiring solid improvements in waste management performances; (ii) few peer-reviewed research studies are performed in Romania for both macro and microplastic concerns with unknown pollution levels in most of its geographical regions; (iii) the plastic waste management is still understudied here, while waste statistics are poorly available at local levels; (iv) the perspectives of circular economy transition are still limited, feeding the plastic pollution in the coming years. Conclusions Several knowledge gaps are identified and must be covered by future research such as (i) adjusting mismanaged plastic waste levels to regional waste management performances and determining littering rates in urban and rural areas to improve the plastic pollution modeling inputs; (ii) examining plastic pollution associated with landfill sites and waste imports; (iii) assessing the sectoral contributions to macro and microplastic pollution of aquatic environments related to municipalities, tourist destinations, agriculture, etc.; (iv) determining retention levels of plastic in river basins and role of riparian vegetation; (v) analyzing microplastics presence in all types of freshwater environments and interlinkage between macroplastic fragmentation and microplastic; (vi) assessing the plastic loads of transboundary rivers related to mismanagement practices; (vii) determining concentrations of microplastics in air, soil, and other land use ecosystems.

This study investigates plastic litter on two beaches in Malta, Golden Bay and Rivera Beach, with a focus on plastic abundance, characteristics, sources, and the influence of human activity on pollution levels. Conducted in March 2023 during the low-tourist season, 13 sediment samples were collected from a depth of 5 cm using a systematic square sampling method. Plastic litter was quantified and sorted by size, shape, color, and polymer type, and concentrations of potentially toxic elements (PTEs) were measured (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and Fe via ICP-OES). Golden Bay exhibited significantly higher plastic quantities (53.9 ± 4.3 n/m2) compared to Rivera Beach (29.7 ± 4.0 n/m2). Microplastics were dominant on both beaches, with Golden Bay showing a higher proportion (57.0%) than Rivera Beach (50.6%). The plastic litter predominantly consisted of PE (59.6–68.0%) and PP (29.6–38.8%). Golden Bay plastics had PTE concentrations up to 4.9 times higher than those in Rivera Beach, notably for Mn (309.0 μg/g vs. 63.1 μg/g). This research contributes valuable insights into the dynamics of plastic pollution in coastal environments, particularly in areas influenced by tourism.

Abstract Background Plastic greenhouse farming has become widespread worldwide because of its contributions to various agricultural production. However, it also generates plastic waste in large quantities and pollutes farmlands. Contrary to studies on microplastics, few studies have quantified macroplastic contamination in agricultural farmlands despite its contribution to the production of microplastics through fragmentation. Thus, there is a paucity of knowledge on the levels and characteristics of macroplastics in greenhouse environments. Thus, this study aimed to quantify and examine the macroplastic litter on soil surfaces under fallow greenhouse farmlands. Results The study was conducted at three sites in Southern Hungary, where the usage of plastic greenhouses is very common for cultivating vegetables. On the studied fallow plots, the overall mean abundance of macroplastics was 431 pieces/ha or 6 kg/ha. Most of the fragments had 0.5- to 5-cm sizes. The macroplastic fragmentation in the area was well detected and was an ongoing process. The dominant plastic types were polyethylene and polyvinyl chloride in the form of films and fragments. The results showed that agricultural litter comprised 90% of the total contamination, whereas nonagricultural litter (10%) due to illegal littering also appeared on the plots. Conclusions Given that macroplastics were found in the studied greenhouse farmlands, we recommend the following: (1) careful cleaning and disposal of plastics on greenhouse farmlands and (2) prevention of greenhouse farmland contamination by external and nonagricultural contaminants. Besides, further research is needed to elucidate the duration of macroplastic fragmentation to microplastic contaminants in greenhouse environments.

Abstract Non-Technical Summary Plastic harms ecosystem health and human livelihood on land, in rivers, and in the sea. To prevent and reduce plastic pollution, we must know how plastics move through the environment. Extreme events, such as floods, bring large amounts of plastic into rivers around the world. This article summarizes how different flood types (excessive rainfall, high river flow, or floods from the sea) flush or deposit plastic pollution, and how this impacts the environment. Furthermore, this paper also discusses how improved resilience to floods is important to prevent and reduce plastic pollution. Technical Summary Plastic pollution is ubiquitous in the environment and threatens terrestrial, freshwater, and marine ecosystems. Reducing plastic pollution requires a thorough understanding of its sources, sinks, abundance, and impact. The transport and retention dynamics of plastics are however complex, and assumed to be driven by natural factors, anthropogenic factors, and plastic item characteristics. Current literature shows diverging correlations between river discharge, wind speed, rainfall, and plastic transport. However, floods have been consistently demonstrated to impact plastic transport and dispersal. This paper presents a synthesis of the impact of floods on plastic pollution in the environment. For each specific flood type (fluvial, pluvial, coastal, and flash floods), we identified the driving transport mechanisms from the available literature. This paper introduces the plastic-flood nexus concept, which is the negative feedback loop between floods (mobilizing plastics), and plastic pollution (increasing flood risk through blockages). Moreover, the impact of flood-driven plastic transport was assessed, and it was argued that increasing flood resilience also reduces the impact of floods on plastic pollution. This paper provides a perspective on the importance of floods on global plastic pollution. Increasing flood resilience and breaking the plastic-flood nexus are crucial steps toward reducing environmental plastic pollution. Social Media Summary Floods have a large impact on plastic pollution transport, which can be reduced through improved flood resilience

The present study described the most recent findings concerning the abundance and distribution of plastic in water, sediment, and fauna in the Nile River of Upper Egypt as an interesting research point. The findings revealed that plastics were abundant in the water, sediments, fish, and crayfish throughout the sites. The Nagaa Hammadi site has the highest abundance of meso- and macroplastics in its water and sediment. African catfish had the highest abundance of meso- and macroplastics compared to the other species, while Nile tilapia had no meso- or macroplastics in its alimentary canal or gills in all sites. The Edfu site has the highest abundance of mesoplastics in the alimentary canals of African catfish, while the Nagaa Hammadi site has the highest abundance of mesoplastics in the gills, and macroplastics appeared only in the alimentary canal of African catfish from the El-wasta site. Only mesoplastics were found in the crayfish's alimentary canal, with the Nagaa Hammadi site having the highest abundance. No macroplastics were detected in the crayfish's gills or alimentary canal. Additionally, this work lets us understand how plastics behave in freshwater environments, and it is a step toward decision-makers taking appropriate measures to reduce their risk. [ABSTRACT FROM AUTHOR]

Background: Plastic greenhouse farming has become widespread worldwide because of its contributions to various agricultural production. However, it also generates plastic waste in large quantities and pollutes farmlands. Contrary to studies on microplastics, few studies have quantified macroplastic contamination in agricultural farmlands despite its contribution to the production of microplastics through fragmentation. Thus, there is a paucity of knowledge on the levels and characteristics of macroplastics in greenhouse environments. Thus, this study aimed to quantify and examine the macroplastic litter on soil surfaces under fallow greenhouse farmlands. Results: The study was conducted at three sites in Southern Hungary, where the usage of plastic greenhouses is very common for cultivating vegetables. On the studied fallow plots, the overall mean abundance of macroplastics was 431 pieces/ha or 6 kg/ha. Most of the fragments had 0.5- to 5-cm sizes. The macroplastic fragmentation in the area was well detected and was an ongoing process. The dominant plastic types were polyethylene and polyvinyl chloride in the form of films and fragments. The results showed that agricultural litter comprised 90% of the total contamination, whereas nonagricultural litter (10%) due to illegal littering also appeared on the plots. Conclusions: Given that macroplastics were found in the studied greenhouse farmlands, we recommend the following: (1) careful cleaning and disposal of plastics on greenhouse farmlands and (2) prevention of greenhouse farmland contamination by external and nonagricultural contaminants. Besides, further research is needed to elucidate the duration of macroplastic fragmentation to microplastic contaminants in greenhouse environments. [ABSTRACT FROM AUTHOR]

Abstract Researchers are focused on the global issue of plastic contamination in agricultural soils because of the known effects of plastics on the soil ecosystem. Previous reviews did not pay attention to plastic sources, standardized extraction methods, soil characterization, and the abundance of plastics in agricultural soils. This study aims to review up-to-the-minute knowledge about plastic contamination studies, suggest the best method for microplastic studies, and propose future research areas. The research about plastic contamination in agricultural soils published from January 2018 to March 2022 was reviewed for this review article. Studies focusing on microplastics in soils other than agricultural soils were not considered in the present review. The data were acquired from several databases, namely Web of Science and Google Scholar. The keywords used to search these databases were "microplastics AND agricultural soils" and "macroplastics AND agricultural soils". Other literature sources were obtained from the reference lists of downloaded articles, and other pieces of literature that directly dealt with macroplastic and microplastic contamination in agricultural soils were obtained from relevant journals and books. Overall, 120 sources of literature, including 102 original research articles, 13 review articles, and five books, were selected, reviewed, and synthesized. As expected, agricultural soils, including arable lands, paddy lands, uplands, irrigation, and greenhouse soils, receive plastic contaminants. The contaminants of different sizes and forms are distributed spatially and temporally in the surface, subsurface, and profiles of the agricultural soils. Unlike previous studies that reported many studies on sewage sludge, the significant sources of plastic contamination in the agricultural soils included mulching, sludge and compost placement, and greenhouses abandonment. The distribution of plastic contamination studies in the agricultural lands is Asia: 60%; Europe: 29%; Africa: 4%; North America: 4%; Latin America: 3%; and Australia: 0%. After careful analysis of the methods used for the plastics contamination studies, the study concluded that floatations with low-density solutions such as distilled water and NaCl are efficient in separating light-density microplastics. In contrast, ZnCl and NaI are incredibly efficient in separating the heavy-density microplastics. Moreover, this review provides insight for future research in the field.

Accumulation of plastic litter in aquatic environments negatively impacts ecosystems and human livelihood. Urban areas are assumed to be the main source of plastic pollution in these environments because of high anthropogenic activity. Yet, the drivers of plastic emissions, abundance, and retention within these systems and subsequent transport to river systems are poorly understood. In this study, we demonstrate that urban water systems function as major contributors to river plastic pollution, and explore the potential driving factors contributing to the transport dynamics. Monthly visual counting of floating litter at six outlets of the Amsterdam water system results in an estimated 2.7 million items entering the closely connected IJ river annually, ranking it among the most polluting systems measured in the Netherlands and Europe. Subsequent analyses of environmental drivers (including rainfall, sunlight, wind speed, and tidal regimes) and litter flux showed very weak and insignificant correlations (r = - 0.19–0.16), implying additional investigation of potential drivers is required. High-frequency observations at various locations within the urban water system and advanced monitoring using novel technologies could be explored to harmonize and automate monitoring. Once litter type and abundance are well-defined with a clear origin, communication of the results with local communities and stakeholders could help co-develop solutions and stimulate behavioral change geared to reduce plastic pollution in urban environments. [ABSTRACT FROM AUTHOR]

Despite the substantial impact of rivers on the global marine litter problem, riverine litter has been accorded inadequate consideration. Therefore, our objective was to detect riverine litter by utilizing middle-scale multispectral satellite images and machine learning (ML), with the Tisza River (Hungary) as a study area. The Very High Resolution (VHR) images obtained from the Google Earth database were employed to recognize some riverine litter spots (a blend of anthropogenic and natural substances). These litter spots served as the basis for training and validating five supervised machine-learning algorithms based on Sentinel-2 images [Artificial Neural Network (ANN), Support Vector Classifier (SVC), Random Forest (RF), Naïve Bays (NB) and Decision Tree (DT)]. To evaluate the generalization capability of the developed models, they were tested on larger unseen data under varying hydrological conditions and with different litter sizes. Besides the best-performing model was used to investigate the spatio-temporal variations of riverine litter in the Middel Tisza. According to the results, almost all the developed models showed favorable metrics based on the validation dataset (e.g., F1-score; SVC: 0.94, ANN: 0.93, RF: 0.91, DT: 0.90, and NB: 0.83); however, during the testing process, they showed medium (e.g., F1-score; RF:0.69, SVC: 0.62; ANN: 0.62) to poor performance (e.g., F1-score; NB: 0.48; DT: 0.45). The capability of all models to detect litter was bounded to the pixel size of the Sentinel-2 images. Based on the spatio-temporal investigation, hydraulic structures (e.g., Kisköre Dam) are the greatest litter accumulation spots. Although the highest transport rate of litter occurs during floods, the largest litter spot area upstream of the Kisköre Dam was observed at low stages in summer. This study represents a preliminary step in the automatic detection of riverine litter; therefore, additional research incorporating a larger dataset with more representative small litter spots, as well as finer spatial resolution images is necessary. [ABSTRACT FROM AUTHOR]

In recent years, there is great concern about plastic pollution due to the identification of several environmental risks associated with microplastics (

In recent years, there is great concern about plastic pollution due to the identification of several environmental risks associated with microplastics (

Plastic waste has become a hot topic in sustainability and conservation, helped in part by popular documentaries which have highlighted the issue to the general public. Much of the current literature focuses on the effect of microplastics in the marine environment, with very little information on macroplastic interactions or the terrestrial environment. In this report, the management of digit constriction due to macroplastic debris in a Verreaux’s eagle owl (Bubo lacteus) is presented, and the role of zoos in decreasing littering behaviour both within the collection and in the wider global context is discussed.

Plastic pollution in rivers is of increased global concern. Rivers act both as pathways for land-based plastic waste into the ocean, and as plastic reservoirs for long-term retention. Reliable observations are key to designing, optimizing and evaluating strategies to prevent and reduce plastic pollution. Several measurement methods have been developed to quantify macroplastic (>0.5 cm) storage and transport in rivers, including visual counting from bridges, net sampling, and images-based techniques. Method harmonization is crucial to make sure data collected using different techniques remains consistent. In turn, this would allow for comparative analysis of plastic pollution within and between rivers. In this paper, we present a harmonization approach to estimate floating plastic item and mass transport from data collected using different methods. The approach allows estimating the same values based on different measurement methods and data collection protocols. We applied our approach to the Mekong-Tonlé Sap-Bassac river system around the city of Phnom Penh, Cambodia. We estimated the floating plastic item and mass transport in the wet and dry season by combining data from net sampling and visual counting. During the wet season, plastic transport in the Mekong increased with a factor of up to 170 (item transport) and 294 (mass transport) compared to the dry season. The river plastic mass balance around Phnom Penh changed considerably, which was mainly due to the flow reversal of Tonlé Sap river between the wet and dry season. Downstream of Phnom Penh, the total plastic transport was consistently higher than upstream, although less in the wet season (1.5–1.7 times) compared to the dry season (3.8–5.9 times), emphasizing the city’s role as entry point of plastic pollution into the Mekong. The largest sources of uncertainty are assumed to be caused by key differences between methods, including the size ranges, extrapolation from observation point to full river width, and the contribution of submerged plastic to the total transport. Future work should focus on including data from other methods than net sampling and visual counting, and reducing the uncertainties related to combining data from different methods. Our results show that river plastic transport dynamics are highly variable over time and space, especially around confluences, bifurcations and urban areas. With our paper we aim to contribute to further harmonization of river plastic monitoring.

Plastics have brought many benefits to society, but their mismanagement has turned them into a serious environmental problem. Today, the effects of plastic waste on wildlife are becoming increasingly evident. Since studies on plastic pollution have focused on species in marine ecosystems, here we review current knowledge on interactions between terrestrial mammals and plastic waste in the countries of the Americas, which is a global hotspot of mammalian biodiversity and in turn has, among its member countries, nations with high per capita generations of plastic waste globally. We identified 46 scientific articles documenting plastic ingestion in 37 species and four species that used plastic waste for nest or burrow construction. Of the 46 investigations, seven focused on plastic contamination, while the others reported on the presence of plastics in wildlife, even though this was not the primary focus of the research. However, these publications lack analytical methods commonly used in plastic studies, and only one study applied a standardized methodology for plastic detection. Therefore, in general, plastic pollution research on terrestrial mammals is limited. We extend several recommendations such as designing methodologies that are adapted to terrestrial mammals for the identification of plastics in fecal matter or gastrointestinal contents, carrying out species-specific analyzes on the impacts of plastics in nests or burrows, and giving further attention to this understudied issue and taxa. [ABSTRACT FROM AUTHOR]

The climbing perch Anabas testudineus is widespread in the inland waters of Vietnam and according to its ecology could have contact with floating plastic waste. Fragments of expanded polystyrene (EPS) are detected in the fresh waters of Vietnam in Khanh Hoa, Lam Dong, and Phu Yen provinces. Our study focused on estimating the probability of ingestion of EPS pellets (size 2.5–3.5 mm) by adult climbing perch. In the experiments, 3 types of treatment pellets were offered to fish: 24 feed pellets (Fps), 24 expanded polystyrene pellets (Pps), and 12 feed and 12 expanded polystyrene pellets (FPps). Fish grasping time of the first pellet was independent in all treatment types. The grasping time of the 12th pellet was insignificant in Fps (63 s) and Pps (75 s). Climbing perch grasped and ingested the 24th Fp significantly (p = 0.02) earlier (143 s), than they grasped the 24th Pp (817 s). Fish with FPp treatment grasped feed along with EPS pellets, but grasping the 12th Fp was significantly (p = 0.02) earlier (49 s) than the 12th Pp (193 s). By the end of the tests, the fish had ingested all feed pellets. We discovered that climbing perch grasped Pps and kept them in the oral cavity, but rejected them in 100% of the cases. This result provided evidence that climbing perch have an effective defense mechanism for avoiding ingestion of expanded polystyrene pellets with a size of 2.5–3.5 mm. [ABSTRACT FROM AUTHOR]

Researchers are focused on the global issue of plastic contamination in agricultural soils because of the known effects of plastics on the soil ecosystem. Previous reviews did not pay attention to plastic sources, standardized extraction methods, soil characterization, and the abundance of plastics in agricultural soils. This study aims to review up-to-the-minute knowledge about plastic contamination studies, suggest the best method for microplastic studies, and propose future research areas. The research about plastic contamination in agricultural soils published from January 2018 to March 2022 was reviewed for this review article. Studies focusing on microplastics in soils other than agricultural soils were not considered in the present review. The data were acquired from several databases, namely Web of Science and Google Scholar. The keywords used to search these databases were "microplastics AND agricultural soils" and "macroplastics AND agricultural soils". Other literature sources were obtained from the reference lists of downloaded articles, and other pieces of literature that directly dealt with macroplastic and microplastic contamination in agricultural soils were obtained from relevant journals and books. Overall, 120 sources of literature, including 102 original research articles, 13 review articles, and five books, were selected, reviewed, and synthesized. As expected, agricultural soils, including arable lands, paddy lands, uplands, irrigation, and greenhouse soils, receive plastic contaminants. The contaminants of different sizes and forms are distributed spatially and temporally in the surface, subsurface, and profiles of the agricultural soils. Unlike previous studies that reported many studies on sewage sludge, the significant sources of plastic contamination in the agricultural soils included mulching, sludge and compost placement, and greenhouses abandonment. The distribution of plastic contamination studies in the agricultural lands is Asia: 60%; Europe: 29%; Africa: 4%; North America: 4%; Latin America: 3%; and Australia: 0%. After careful analysis of the methods used for the plastics contamination studies, the study concluded that floatations with low-density solutions such as distilled water and NaCl are efficient in separating light-density microplastics. In contrast, ZnCl and NaI are incredibly efficient in separating the heavy-density microplastics. Moreover, this review provides insight for future research in the field. [ABSTRACT FROM AUTHOR]

Macrolitter, especially macroplastics, (> 0.5 cm) negatively impact freshwater ecosystems, where they can be retained along lake shores, riverbanks, floodplains or bed sediments. Long-term and large-scale assessments of macrolitter on riverbanks and lake shores provide an understanding of litter abundance, composition, and origin in freshwater systems. Combining macrolitter quantification with hydrometeorological variables allows further study of leakage, transport, and accumulation characteristics. Several studies have explored the role of hydrometeorological factors in influencing macrolitter distribution and found that river discharge, runoff, and wind only partially explains its distribution. Other factors, such as land-use features, have not yet been thoroughly investigated. In this study, we provide a country-scale assessment of land-use influence on macrolitter abundance in freshwater systems. We analyzed the composition of the most commonly found macrolitter items (referred to as 'top items', n = 42,565) sampled across lake shores and riverbanks in Switzerland between April 2020 and May 2021. We explored the relationship between eleven land-use features and macrolitter abundance at survey locations (n = 143). The land-use features included buildings, city centers, public infrastructure, recreational areas, forests, marshlands, vineyards, orchards, other land, and rivers and canals. The majority of top items are significantly and positively correlated with land-use features related to urban coverage, notably roads and buildings. Over 60% of top items were found to be correlated with either roads or buildings. Notably, tobacco, food and beverage-related products, as well as packaging and sanitary products, showed strong associations with these urban land-use features. Other types of items, however, did not exhibit a relationship with land-use features, such as industry and construction-related items. Ultimately, this highlights the need to combine measures at the local and regional/national scales for effective litter reduction. [Display omitted] • 60% of macrolitter items at freshwater shores correlate with roads or buildings. • Industry and construction items show insignificant correlations with local land use. • Results suggest combining local and regional/national litter reduction measures. [ABSTRACT FROM AUTHOR]

The research on the impact of plastic pollution on biodiversity has primarily focused on aquatic ecosystems, especially marine ones. Therefore, it is vital to assess how plastic pollution affects other environments and organisms, including terrestrial invertebrates. These organisms are widely recognized for their susceptibility to environmental changes and pollution. The objectives of this study were i) to investigate the potential influence (positive or negative) of macroplastic debris (MaP) on invertebrates inhabiting riverine sandy environments, ii) the potential occurrence of the microplastic (MP) adherence phenomenon on the invertebrate's body by entanglement on the body's setae or electrostatic effect (i.e., bioadhesion), and iii) the effects of removal of debris on the colonized diversity. By performing a mesocosm experiment, emulating a "small-scale dump" (also called micro-waste sites), we found that terrestrial invertebrates show a preference for colonizing areas rich in MaP, resulting in higher species richness in these areas (39 taxa in areas containing plastic debris vs. 21 taxa in areas free of plastics). This preference is likely due to the provision of shade, protection, and distinct micro-habitats offered by MaP. Regarding MP, we observed a significant number of invertebrates with MPs attached to their bodies (4.3 ± 0.8 MPs attached per individual), mainly wolf spiders (Lycosidae) and ground beetles (Carabidae), suggesting potential negative ecological implications that are discussed herein. [Display omitted] • Terrestrial invertebrates showed greater diversity in areas affected by plastics. • Small-scale dumps can serve as refuges and feeding grounds for invertebrates. • Invertebrates exhibited bioadhesion of microplastics on their bodies. [ABSTRACT FROM AUTHOR]

The presence of plastic debris along shorelines is a widespread problem, and plastic debris can interact directly with marine wildlife. In northeast Brazil, the Antillean manatees are the most common marine mammals and use estuarine waters mainly as their home range. We aimed to investigate the characteristics of plastic debris on the estuarine-oceanic continuum and the accumulation density of plastic on beaches. The density of plastic debris on beaches located in transitional areas was 7–10-fold greater than that on beaches in estuarine and oceanic areas. Fragments were considered the most abundant form of plastic debris on all the beaches. Our findings could lead to improved pollution management in this marine protected area, principally due to the risks of remobilizing small plastic particles through tides and wind effects that scatter them in resting and feeding manatees areas. • Fragments were the most abundant form of plastic debris in the beaches. • The most common color of the plastics was white. • Macro- and mesoplastics were found widely present on all the beaches. • Sand spits provided a barrier to the transport of plastic debris. [ABSTRACT FROM AUTHOR]

This work describes for the first time the presence of pyroplastics in the Canary Islands (Spain). A total of 300 pyroplastics, identified between 2021 and 2024 in three beaches of the island of Tenerife, present mainly grey and dark colors, a mean weight of 6.8 ± 13.4 g and mean dimensions of 34.2 ± 17.0 mm (X), 24.5 ± 12.2 mm (Y) and 14.4 ± 6.4 (Z). A wide variety of encapsulated and semi-encapsulated materials were also found in the pyroplastics matrix, such as rocks, wood, charcoal and unmelted plastic inclusions. Fourier-transform infrared spectroscopy analysis revealed that polyethylene and polypropylene were the main types of plastic found, 61.3 % and 33.6 %, respectively. However, an important number of pyroplastics composed of more than one polymer were also found, coexisting even mixtures of polyester and polyethylene or polyethylene and styrene-ethylene-butylene-styrene in the same matrix. X-ray fluorescence spectroscopy analysis revealed the presence of a wide range of elements, being remarkable the high concentration of some heavy metals such as Pb and Cr, registering mean concentration values of 205.3 ± 6.3 mg·kg−1 and 51.1 ± 8.9 mg·kg−1, respectively. A good correlation was also found for these two metals in a total of 22 pyroplastics, which could be indicative of the presence of PbCrO 4 as additive, widely used in the plastic industry for its bright yellow color, but currently regulated and restricted due to its harmful effects on human and environment health. Also noteworthy is the large variety of remains of marine organisms identified attached to the surface of the pyroplastics, such as algae, bryozoans, arthropods and molluscs, among others, which could indicate that these formations may act as a transport vector for such marine organisms. [Display omitted] • Pyroplastic pollution (n = 300) was first reported on the Canary Islands (Spain). • An important number of pyroplastics composed of more than one polymer were found. • Pyroplastics contained encapsulated and semi-encapsulated materials. • A positive correlation between Pb and Cr concentrations was found. • Pyroplastics are acting as a substrate of different marine organisms. [ABSTRACT FROM AUTHOR]

Expanded polystyrene (EPS), commonly known as Styrofoam, is a foam plastic material regularly found in the marine environment. The objective of this study is to investigate the frequency of EPS among all plastic waste on beaches and in marine surface waters in order to evaluate its spatial variability. On average, 23.0% and 17.2% of plastics on beaches and in marine surface waters are composed of EPS, respectively. In Asia, 40.4% and 31.0% of plastic on beaches and in marine surface waters are EPS, significantly higher than the rest of the world where EPS only accounts for 17.3% and 6.5% on beaches and in water. Higher EPS proportions are observed in Asia for both macro- and microplastics. Among the seven sub-regions identified outside of Asia, the Mediterranean and Black Sea sub-region has the highest EPS proportion in beach while the Indian Ocean sub-region has the highest EPS proportion in water. A comparison between macro- and microplastic from selected studies suggests that the rate of fragmentation may be higher on beaches than in marine waters. We have highlighted fishery activity, tropical cyclones, and open dumping as major factors contributing to the high proportion of EPS in the Asian region. Finally, we evaluated EPS bans in different parts of the world and concluded that while bans may be effective in reducing EPS input into the marine environment, other factors should be considered when implementing these policies.

Plastic pollution in rivers threatens ecosystems, increases flood risk due to its accumulations at hydraulic structures and its final emissions into the ocean threaten aquatic life, especially and probably most in coastal urbanized areas. Previous work suggests that plastic pollution in these urban rivers is influenced by hydrometeorological and anthropogenic factors. However, the transport dynamics of the plastics in such rivers are non-linear and complex and remain largely unresolved. Here, we show that tidal dynamics can be the main driver of plastic transport closest to the river mouth. Outside the tidal zone, rainfall and river discharge were identified to be more important drivers. We monitored plastic transport in the Odaw river, Ghana during the dry season. The Odaw drains the densely populated city of Accra and discharges into the Gulf of Guinea. Data were collected between March and May 2021 (dry season), using visual counting at four bridges along the river, of which two were located within the tidal zone. We explored the correlations between river plastic transport, and rainfall, tidal dynamics, and river discharge. Finally, we estimated the total plastic mass transport by using item-to-mass conversion data from previously published literature. We observed a peak in plastic transport at the upstream bridge within the tidal zone after an increase in rainfall (7.3 times larger). We found a gradient of the hydrometeorological factors driving plastic transport. Closer to the river mouth, tidal dynamics were more strongly correlated with plastic transport than upstream. The daily mass transport was estimated to be between 1.4–3.8 × 102 kg/d, which is lower than previous model estimates. These results add to the evidence of inconsistent correlations between plastic transport and hydrometeorological variables. Long-term monitoring data is required to further investigate this. The results also support the hypothesis that tidal dynamics are a crucial factor in controlling the emissions of plastics from rivers into the ocean. The findings provide a baseline for the Odaw river during the dry season and allow for comparison with the wet season. The approach adopted here also serves as a blueprint for similar urban river systems, regionally and globally.

Microfibers are small (<5 mm) fibers made of synthetic materials that are ubiquitous in the environment. The purpose of this observational study was to quantify the number of microfibers in marine sediments and determine which locations have the highest risk for this type of pollution. Sediment samples were taken from three locations in Southern California (Sycamore Watershed, Ventura State Beach Jetty, and Newport Beach Harbor) to determine which had the highest number of microfibers. It was hypothesized that microfibers would be found at each sample site and that the most microfibers would be found at Sycamore Watershed due to its proximity to a wastewater discharge point. The microfibers were separated from the sediment through a process of stratification and filtration and analyzed by a one-way ANOVA and Tukey s test. Per sample, there was an average of 111.5 (±99.3, n=14) microfibers found per sample at Sycamore Watershed, 59 (±17.4, n=18) at Newport Beach Harbor, and 53 (±14.4, n=18) at Ventura State Beach Jetty. A total of 3,590 microfibers were found from all three sample sites. Analysis revealed that Sycamore Watershed had significantly more microfibers than any other site (p<.05). It is likely that Sycamore Watershed had the most microfibers because of its proximity to a sewage-sludge disposal site that contains the polluted water from our washing machines. In conclusion, microfibers are polluting the sediments in harbors, open coastlines, and watersheds in California, negatively affecting the ecosystems in these areas. [ABSTRACT FROM AUTHOR]

Greenhouse plastic contaminations in agricultural soils were studied to quantify and examine the macroplastic and microplastic contaminants on the soil surface, soil profile, and groundwater under greenhouse farmland. Random sampling was used to select three areas in a greenhouse farm where macroplastic and microplastic data were collected. Four composite samples were collected from shallow (0-20 cm) and deep (20-40 cm) soils for each sampling point, respectively. Three soil profiles were dug, and samples were collected at intervals of 20 cm. Groundwater samples were also collected from the same profiles at a depth of 100 cm. Microplastics were extracted using predigestion of organic matter with 30% H2O2 and density separation with ZnCl2. The total mass of macroplastics in the greenhouse farmland was 6.4 kg ha-1. Polyethylene and polyvinyl chloride were the dominant plastic structures, and the dominant sizes were 1-5 and 0.5-1.0 cm, respectively. Overall, the average abundance of microplastics in the greenhouse soil was 225 ± 61.69 pieces/kg, and the dominant size structure was 2-3 mm. The average microplastic concentrations at depths of 0-20 and 20-40 cm were 300 ± 93 and 150.0 ± 76.3 pieces/kg, respectively. The average microplastic concentration in the groundwater was 2.3 pieces/l, and fibers were the dominant plastic structure. Given that microplastics were found in greenhouse soil, soil profiles, and groundwater, we recommend the careful cleaning and disposal of plastics on greenhouse farmland and further research to shed light on the level of microplastic contamination in the soil profiles and groundwater. [ABSTRACT FROM AUTHOR]

Mangroves are recognized as a sink for plastic and other anthropogenic marine debris (AMD). The accumulation rates of AMD within these ecosystems, however, have not yet been assessed anywhere in the world. Here, we investigated the standing stock and accumulation rate of AMD at four of the most polluted mangroves in Hong Kong over one year, focussing on its ecological impact on the diversity and abundance of vegetation and benthic macrofauna. Plastics accounted for ~80 % of the recorded AMD. The AMD accumulated at an average rate of 0.025 ± 0.141 items m -2 . d -1 across all study sites. Mangroves on the east coast presented the highest rate (0.071 ± 0.246 items m -2 . d -1 ), while those on the west had the lowest (0.001 ± 0.005 items m -2 . d -1 ). The accumulation rate of debris varied significantly across zones (landward vs seaward), months, and sites, with landward zones generally serving as sinks for debris items. Mangrove sapling density also varied significantly among sites, species, and zones. A significant positive relationship between the surface area covered by debris and mangrove sapling density was observed. No significant effect on the diversity of macrobenthic crabs and gastropods was observed, which may reflect the resilience of the ecosystem's faunal components., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Anthropogenic litter is omnipresent in terrestrial and freshwater systems, and can have major economic and ecological impacts. Monitoring and modeling of anthropogenic litter comes with large uncertainties due to the wide variety of litter characteristics, including size, mass, and item type. It is unclear as to what the effect of sample set size is on the reliability and representativeness of litter item statistics. Reliable item statistics are needed to (1) improve monitoring strategies, (2) parameterize litter in transport models, and (3) convert litter counts to mass for stock and flux calculations. In this paper, we quantify sample set size requirement for riverbank litter characterization, using a database of more than 14,000 macrolitter items (>0.5 cm), sampled for 1 year at eight riverbank locations along the Dutch Rhine, IJssel, and Meuse rivers. We use this database to perform a Monte Carlo based bootstrap analysis on the item statistics, to determine the relation between sample size and variability in the mean and median values. Based on this, we present sample set size requirements, corresponding to selected uncertainty and confidence levels. Optima between sampling effort and information gain is suggested (depending on the acceptable uncertainty level), which is a function of litter type heterogeneity. We found that the heterogeneity of the characteristics of litter items varies between different litter categories, and demonstrate that the minimum required sample set size depends on the heterogeneity of the litter category. This implies that more items of heterogeneous litter categories need to be sampled than of heterogeneous item categories to reach the same uncertainty level in item statistics. For example, to describe the mean mass the heterogeneous category soft fragments (>2.5 cm) with 90% confidence, 990 items were needed, while only 39 items were needed for the uniform category metal bottle caps. Finally, we use the heterogeneity within litter categories to assess the sample size requirements for each river system. All data collected for this study are freely available, and may form the basis of an open access global database which can be used by scientists, practitioners, and policymakers to improve future monitoring strategies and modeling efforts.

In recent years, citizen science has proven to be an effective means of monitoring plastic litter, bring potential benefits to professional researchers and authorities, and create awareness on plastic pollution at a society level. This paper aims to review the advances of employing the citizen science approach for plastic litter evaluation and explore the research contributions of these initiatives and their impact at the society and environmental levels. A systematic search was undertaken using the main scientific paper databases and back-referencing from reviewed papers over a period of 10 years. Out of 221 papers found, only 94 papers that discussed plastic litter/waste and citizen science remained in the analysis. Geographically, 66% of the studies were concentrated in the Northern Hemisphere (mostly in USA). The majority were related to clean-up activities that analysed litter density, types, and potential sources. The results showed that citizens can provide data over large geographical regions and can be essential to researchers and authorities in implementing litter management policies. Citizen science programs are effective in creating awareness and increasing education regarding plastic litter pollution and impact. However, it is not clear if they can enhance behavioural changes after participation in field survey programs. [ABSTRACT FROM AUTHOR]

Plastic waste has become a hot topic in sustainability and conservation, helped in part by popular documentaries which have highlighted the issue to the general public. Much of the current literature focuses on the effect of microplastics in the marine environment, with very little information on macroplastic interactions or the terrestrial environment. In this report, the management of digit constriction due to macroplastic debris in a Verreaux's eagle owl (Bubo lacteus) is presented, and the role of zoos in decreasing littering behaviour both within the collection and in the wider global context is discussed. [ABSTRACT FROM AUTHOR]

Literature review identified seven principal pathways of plastic debris entry into river systems: waste water treatment plants; combined sewer overflows; on-site wastewater treatment systems; road and rail transport systems; agriculture; industrial sources; and diffuse litter. A further category of 'microplastics' reflects their multiple potential sources, including microplastic breakdown within rivers. Regulatory and management bodies necessarily make operational decisions based on resource limitations and significant uncertainty due to sparse or missing data, requiring a substantial degree of inference. To support this need, we develop a rapid, desk-based approach based on risk criteria to 'fingerprint' likely pathways of plastic pollution based on catchment characteristics. Characteristics of the River Wye system in the UK are reviewed identifying a risk-based 'fingerprint' of potential pathways of plastic entry or accumulation of plastic debris, represented graphically as a colour-coded 'traffic lights' classification. This 'fingerprinting' approach is based on desk-based inference from published materials as a rapid and resource-efficient alternative to intensive data collection, supporting prioritization of further investigation or response measures. We recommend replication of this 'fingerprinting' approach in other river catchments to support operational management of plastic pollution. Where feasible, it may also be down-scaled where sub-catchment or major river reach properties differ significantly. HIGHLIGHTS Unique catchment characteristics influence likely sources of plastics in rivers Seven potential plastic sources were identified, with a residual microplastics category Literature, interviews and surveys can rapidly 'fingerprint' likely plastic sources Fingerprinting can prioritize management and investigations in specific catchments [ABSTRACT FROM AUTHOR]

Plastic pollution in aquatic ecosystems is a growing threat to ecosystem health and human livelihood. Recent studies show that the majority of environmental plastics accumulate within river systems for years, decades and potentially even longer. Long‐term and system‐scale observations are key to improve the understanding of transport and retention dynamics, to identify sources and sinks, and to assess potential risks. The goal of this study was to quantify and explain the variation in floating plastic transport in the Rhine‐Meuse delta, using a novel 1‐year observational data set. We found a strong positive correlations between floating plastic transport and discharge. During peak discharge events, plastic transport was found up to six times higher than under normal conditions. Plastic transport varied up to a factor four along the Rhine and Meuse rivers, which is hypothesized to be related to the complex river network, locations of urban areas, and tidal dynamics. Altogether, our findings demonstrate the important role of hydrology as driving force of plastic transport dynamics. Our study emphasizes the need for exploring other factors that may explain the spatiotemporal variation in floating plastic transport. The world's most polluted rivers are connected to the ocean through complex deltas. Providing reliable observations and data‐driven insights in the transport and dynamics are key to optimize plastic pollution prevention and reduction strategies. With our paper we aim to contribute to both advancing the fundamental understanding of plastic transport dynamics, and the establishment of long‐term and harmonized data collection at the river basin scale. Plain Language Summary: Plastic pollution in rivers and oceans harms ecosystems and human livelihoods. Especially large plastic items (>0.5 cm) can be mistaken for food by animals, damage ships, and block waterways. Knowing how much plastic is floating through rivers is important for policy‐makers to reduce plastic pollution in the environment. In our study, we measured floating plastic pollution in the Rhine and the Meuse, two large European rivers that flow into the ocean in the Netherlands. From January to December 2021, a team of students and volunteers counted plastic items floating in the rivers from bridges. We found that more plastic was counted when the river flow was higher. The highest amount of plastic was measured during two flood events, when parts of the land next to the rivers were flooded. We think that more plastic leaks into the river when streets, riverbanks, and floodplains are under water. We hope that our study can help to better predict how much plastic flows through other big rivers around the world. Only when we know how big the plastic problem is, we can successfully solve it. Key Points: Plastic pollution is a global environmental challenge, but poorly understood and quantified due to a lack of reliable observationsRiver plastic transport increases significantly during discharge during peak eventsHydrology plays a crucial role in the transport and retention dynamics, and the spatiotemporal variation of floating plastic transport [ABSTRACT FROM AUTHOR]

Abstract Plastic pollution in aquatic ecosystems is a growing threat to ecosystem health and human livelihood. Recent studies show that the majority of environmental plastics accumulate within river systems for years, decades and potentially even longer. Long‐term and system‐scale observations are key to improve the understanding of transport and retention dynamics, to identify sources and sinks, and to assess potential risks. The goal of this study was to quantify and explain the variation in floating plastic transport in the Rhine‐Meuse delta, using a novel 1‐year observational data set. We found a strong positive correlations between floating plastic transport and discharge. During peak discharge events, plastic transport was found up to six times higher than under normal conditions. Plastic transport varied up to a factor four along the Rhine and Meuse rivers, which is hypothesized to be related to the complex river network, locations of urban areas, and tidal dynamics. Altogether, our findings demonstrate the important role of hydrology as driving force of plastic transport dynamics. Our study emphasizes the need for exploring other factors that may explain the spatiotemporal variation in floating plastic transport. The world's most polluted rivers are connected to the ocean through complex deltas. Providing reliable observations and data‐driven insights in the transport and dynamics are key to optimize plastic pollution prevention and reduction strategies. With our paper we aim to contribute to both advancing the fundamental understanding of plastic transport dynamics, and the establishment of long‐term and harmonized data collection at the river basin scale.

Microplastic (MP) pollution has been widely reported across water matrices including in estuaries, which are important for the understanding of oceanic MPs. Estuaries can greatly alter the fate, transport, size distribution, and abundance of plastic pollution. The aim of this study was to quantify and characterize MP pollution in the Delaware Bay estuary USA, including the size distribution. Samples (N = 31) were collected from the mouth of the Delaware River to the coastal ocean including multiple frontal zones across two sampling campaigns (2019 and 2022). MP were extracted from the collected particles using wet peroxide oxidation and density separation with saturated sodium chloride. Particles collected on 500 μm mesh sieves were analyzed via Fourier transform infrared (FTIR) spectroscopy. Across all samples, 324 of the 1015 particles analyzed were MP, and 11 macroplastics were observed. MP concentrations ranged from below detection to 4.12 MP/m3 (mean 0.34 ± 0.80 MP/m3). No significant differences were observed between sampling sites; nonetheless, the two highest MP concentrations were observed when sampling along frontal zones with visible debris including macroplastics. Polyethylene (53%) and polypropylene (43%) were the most abundant polymers observed. The majority of the non-plastic particles were classified as particulate natural organic matter (82% of non-plastics). Particles from samples collected during 2022 (N = 864) also had color, morphology, and two size dimensions recorded. MP particle size was significantly associated with sampling site, with the coastal ocean sampling site generally having the smallest MPs. A correlation between total post-extraction particles and total plastic particles was observed. Aspect ratios for the plastics ranged from one to 40.7, with larger ratios for fibers, with a mean (±standard deviation) of 3.39 ± 4.72 (unitless). These aspect ratios can be used to select shape factors used to estimate the total volume of MP in the studied size range. Overall, these results can help inform fate, transport, and risk assessments related to estuarine plastic pollution. [Display omitted] • Polyethylene and polypropylene were most prevalent MP in the Delaware Bay estuary. • Peak plastic concentrations were observed in frontal zones. • Microplastic particle size varied by sampling site, sometimes by polymer type. [ABSTRACT FROM AUTHOR]

Quantifying microplastics (MPs) in marine environments is challenging due to the complexities of differentiation from other materials. This study aims to distinguish petro-sourced plastic microfilaments from organic ones in environmental samples using scanning electron microscope coupled with energy dispersive X-ray (SEM-EDX) analysis. Therefore, 38 particles resembling MPs (PRMPs) from sediments and organisms in Madagascar were analyzed. MPs identification thresholds were determined from SEM-EDX analysis of macroplastics and seaweed, the primary sources of microfilaments. SEM-EDX results of the 38 PRMPs were compared with identification/misidentification made by five MPs observation experts. Results indicated that a carbon/oxygen (C/O) ratio >1 distinguished macroplastics and MPs from other sources (seaweed and organic microfilaments). SEM-EDX analysis identified 81.58% of PRMPs as MPs. The average error made by one observer was 36.32%. These findings highlight the need for a method to assess identification error in MPs quantification and recommend SEM-EDX analysis of microfilaments to gauge observer error. • SEM-EDX reveals atomic differences between organic and petro-sourced microfilaments. • Higher C and O content in macroplastics but biofouling alters these ratios. • C/O ratios facilitate the distinction between plastic microfilaments and organic ones. • Visual identification differs from SEM-EDX, indicating microplastic underestimation. • Petro-sourced microfilaments predominate, highlighting marine pollution in Madagascar. [ABSTRACT FROM AUTHOR]

A growing evidence base has shown that plastics are widely distributed in soils and could have negative effects on soil functions. However, within international standards for soil description, plastics are handled so far as one part of humanmade artefacts. With the ongoing plastic crisis, such a simple classification may no longer be sufficient to provide a satisfactory description of plastics in soils. Based on the latest research on plastics in soils, these foreign components can no longer be understood as relevant only for soils in urban, industrial, traffic, mining and military areas. This perspective therefore aims to suggest a possible approach towards a future and more comprehensive description of plastics in soil characterization. Based on the existing definitions within the international soil description standards, a description concept and a corresponding field guide are proposed. The proposed approach comprises a recent definition of plastics and guidelines for the description of visible plastic residues in soils during field work. Classification approaches are developed for plastics abundance and distribution as well as plastic characteristics. Furthermore, pitfalls during the description, as well as during the extraction of plastics from soils in the field, and further limitations are discussed. Basic soil description during soil surveys or soil mapping, are a strong tool of soil science to derive environmental data sets. The perspective and the field guide presented in this paper are intended to change this circumstance and enable soil scientists to describe plastic residues in soils simple, comparable and adapted to existing standards in future. [ABSTRACT FROM AUTHOR]

The Philippines is the world's third major contributor to global marine plastic pollution and the biggest polluter of riverine plastics into the sea. Several rivers in Philippines including those in Palawan, the country's Last Frontier, are assumed to be the main pathways of land-based plastic waste into the ocean. However, variations, model estimations and plastic litter's composition among rivers remains uncertain due to lack of fild data. In this regard, the quantity, temporal variations and composition of plastic flux were studied in Pulot River and its tributary in Sofronio Española, Palawan. This aims to collect fild data on floating macroplastics and its composition, as well as to determine the effect of flow velocity to plastic flux. Plastic flux was measured at three different locations along Pulot River, two hourly measurements during two different time of the day was made. The results showed significant difference on the amount of plastic flux during the morning and afternoon measurements. On the other hand, plastic flux during the weekends and weekdays measurements showed no significant difference. Instantaneous plastic flux and flow velocity showed significant positive correlation at all locations for all periods of measurements except the Pulot River Bridge during morning. Predominant plastic types are food packaging, plastic bottles, and toiletries. Multilayers and mixed plastics under the "Other" category were the most abundant plastic polymer classifid. These results provide new insights on variations and prevalence of plastic flux in Pulot River which may benefit future long-term monitoring efforts and plastics pollution mitigation strategies. [ABSTRACT FROM AUTHOR]