Article

Export of Plastic Debris by Rivers into the Sea

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Abstract

A substantial fraction of marine plastic debris originates from land-based sources and rivers potentially act as a major transport pathway for all sizes of plastic debris. We analyzed a global compilation of data on plastic debris in the water column across a wide range of river sizes. Plastic debris loads, both microplastic (particles <5 mm) and macroplastic (particles >5 mm) are positively related to the mismanaged plastic waste (MMPW) generated in the river catchments. This relationship is nonlinear where large rivers with population-rich catchments delivering a disproportionately higher fraction of MMPW into the sea. The 10 top-ranked rivers transport 88–95% of the global load into the sea. Using MMPW as a predictor we calculate the global plastic debris inputs form rivers into the sea to range between 0.41 and 4 × 10⁶ t/y. Due to the limited amount of data high uncertainties were expected and ultimately confirmed. The empirical analysis to quantify plastic loads in rivers can be extended easily by additional potential predictors other than MMPW, for example, hydrological conditions.

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... It has been found to negatively impact ecosystems, increase flood risk by blocking hydraulic infrastructure, and cause damage to the human livelihoods in the vicinity of polluted rivers (Van Emmerik and Schwarz, 2020). In addition, plastic emissions from rivers into the sea are assumed to be a major component of marine plastic pollution (Lebreton et al., 2017;Schmidt et al., 2017). However, there is currently a stark mismatch between the amount of plastic estimated to enter the ocean (Jambeck et al., 2015;Lebreton et al., 2017;Schmidt et al., 2017) and the amount of plastic observed in the open ocean (Weiss et al., 2021). ...
... In addition, plastic emissions from rivers into the sea are assumed to be a major component of marine plastic pollution (Lebreton et al., 2017;Schmidt et al., 2017). However, there is currently a stark mismatch between the amount of plastic estimated to enter the ocean (Jambeck et al., 2015;Lebreton et al., 2017;Schmidt et al., 2017) and the amount of plastic observed in the open ocean (Weiss et al., 2021). Understanding the sources, sinks and transport mechanisms of plastic pollution is of key importance in both designing effective monitoring strategies (Vriend et al., 2020b), and developing pollution mitigation and cleanup campaigns (Lebreton et al., 2017). ...
... Castro-Jiménez et al., 2019), to regression models (e.g. Schmidt et al., 2017) and more complex probabilistic modelling approaches (Meijer et al., 2021). ...
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Plastic pollution in the natural environment is causing increasing concern at both the local and global scale. Understanding the dispersion of plastic through the environment is of key importance for the effective implementation of preventive measures and cleanup strategies. Over the past few years, various models have been developed to estimate the transport of plastics in rivers, using limited plastic observations in river systems. However, there is a large discrepancy between the amount of plastic being modelled to leave the river systems, and the amount of plastic that has been found in the seas and oceans. Here, we investigate one of the possible causes of this mismatch by performing an extensive uncertainty analysis of the riverine plastic export estimates. We examine the uncertainty from the homogenisation of observations, model parameter uncertainty, and underlying assumptions in models. To this end, we use the to-date most complete time-series of macroplastic observations (macroplastics have been found to contain most of the plastic mass transported by rivers), coming from three European rivers. The results show that model structure and parameter uncertainty causes up to four orders of magnitude, while the homogenisation of plastic observations introduces an additional three orders of magnitude uncertainty in the estimates. Additionally, most global models assume that variations in the plastic flux are primarily driven by river discharge. However, we show that correlations between river discharge (and other environmental drivers) and the plastic flux are never above 0.5, and strongly vary between catchments. Overall, we conclude that the yearly plastic load in rivers remains poorly constrained.
... Previous studies observed MPs in human bodies (Ragusa et al., 2021;Schwabl et al., 2019), suggesting detrimental impacts on human health (Metcalf et al., 2022;Wright and Kelly, 2017). Although oceanic environments have been widely surveyed (Isobe et al., 2015;Lusher, 2015), the precise mechanisms for MP inputs into the ocean remain unclear (Horton et al., 2017;Rochman, 2018;Schmidt et al., 2017). Notably, substantial fractions of plastic debris generated in river catchments are mismanaged (Nematollahi et al., 2022;Yang et al., 2022;Zhang et al., 2022) and subsequently enter river systems through runoff (Horton et al., 2017;Rochman, 2018;Schmidt et al., 2017); thus, rivers are commonly recognized as the primary pathways that transport MPs to the ocean (Lebreton et al., 2017;Meijer et al., 2021;Schmidt et al., 2017;Weiss et al., 2021;Zhao et al., 2019). ...
... Although oceanic environments have been widely surveyed (Isobe et al., 2015;Lusher, 2015), the precise mechanisms for MP inputs into the ocean remain unclear (Horton et al., 2017;Rochman, 2018;Schmidt et al., 2017). Notably, substantial fractions of plastic debris generated in river catchments are mismanaged (Nematollahi et al., 2022;Yang et al., 2022;Zhang et al., 2022) and subsequently enter river systems through runoff (Horton et al., 2017;Rochman, 2018;Schmidt et al., 2017); thus, rivers are commonly recognized as the primary pathways that transport MPs to the ocean (Lebreton et al., 2017;Meijer et al., 2021;Schmidt et al., 2017;Weiss et al., 2021;Zhao et al., 2019). ...
... Although oceanic environments have been widely surveyed (Isobe et al., 2015;Lusher, 2015), the precise mechanisms for MP inputs into the ocean remain unclear (Horton et al., 2017;Rochman, 2018;Schmidt et al., 2017). Notably, substantial fractions of plastic debris generated in river catchments are mismanaged (Nematollahi et al., 2022;Yang et al., 2022;Zhang et al., 2022) and subsequently enter river systems through runoff (Horton et al., 2017;Rochman, 2018;Schmidt et al., 2017); thus, rivers are commonly recognized as the primary pathways that transport MPs to the ocean (Lebreton et al., 2017;Meijer et al., 2021;Schmidt et al., 2017;Weiss et al., 2021;Zhao et al., 2019). ...
Article
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Microplastics (MPs), plastic particles <5 mm in diameter, have become an emerging ubiquitous concern for the environment. Rivers are the primary pathways that transport MPs from the land to the ocean; however, standardized methodologies for in-situ sampling in freshwater environments remain undefined. Notably, uncertainties in MP sampling methods lead to errors in estimating MP discharge through rivers. In the present study, the inter-sample variance of plankton net-obtained MP concentrations for two urban rivers in Japan was investigated. Numerical concentrations, expressed in particles·m⁻³, revealed that variance s2 was proportional to the mean m of replicated estimates of numerical concentrations. A derived statistical model suggested that river MPs disperse according to purely random processes; that is, Poisson point processes. Accordingly, a method was established to project the “precision,” the ratio of the standard error to m, of numerical concentrations based on the number of net sampling repetitions. It was found that the mean of two replicates maintained sufficient precision of <30% for conditions with high concentrations of ≥3 particles·m⁻³. Projected precisions under different levels of MP concentrations are also presented to help design future field campaigns.
... Diagnosing litter leakage to the environment is fundamental to establish prevention and mitigation measures to solve the problem. Given the well known impacts of plastic litter, leakage to the environment has been estimated worldwide by previous studies, seeking to understand what reaches the ocean Lebreton et al., 2017;Schmidt et al., 2017Schmidt et al., , 2018Lebreton and Andrady, 2019;Meijer et al., 2021). However, studies have provided country-level estimates using few parameters, such as population density, per capita income, and the estimated amount of poorly managed plastics, which, for middle-income countries like Brazil, considers only the amount of litter sent to open dumps plus a flat rate of littering Lebreton et al., 2017;Schmidt et al., 2017Schmidt et al., , 2018. ...
... Given the well known impacts of plastic litter, leakage to the environment has been estimated worldwide by previous studies, seeking to understand what reaches the ocean Lebreton et al., 2017;Schmidt et al., 2017Schmidt et al., , 2018Lebreton and Andrady, 2019;Meijer et al., 2021). However, studies have provided country-level estimates using few parameters, such as population density, per capita income, and the estimated amount of poorly managed plastics, which, for middle-income countries like Brazil, considers only the amount of litter sent to open dumps plus a flat rate of littering Lebreton et al., 2017;Schmidt et al., 2017Schmidt et al., , 2018. Previous studies have also used some outdated and inconsistent data -e.g., past estimates have used waste management information for Brazil, Chile, Colombia, Costa Rica, Peru, Paraguay, Uruguay, among others, that is over two decades old (The World Bank, 2012;PAHO, 2005). ...
... From the literature survey, we identified nine publications, by Jambeck et al. (2015), Hardesty et al. (2016), Lebreton et al. (2017), Schmidt et al. (2017Schmidt et al. ( , 2018, Lebreton and Andrady (2019), Liro et al. (2020), UNEP (2020), Meijer et al. (2021), and PEMALM (2021), considering their adherence to the theme. These publications comprise global and national estimates, as well as a concept paper for estimating plastic litter leakage into the environment, a public policy for monitoring and assessing marine litter in Brazil, and a guide for hotspotting plastic pollution along the value chain. ...
Article
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Litter pollution is a global concern, and identifying sources and pathways is crucial for proposing preventative actions. Existing models of plastic litter leakage to the environment have provided worldwide estimates at a country-based level, but only a few initiatives address subnational scales. Adding relevant parameters and improving models is needed to reduce the limitations of global estimates. However, availability of information, which varies among countries and is critical in the Global South, may preclude such improvements. To understand the potentialities and limitations of subnational estimates of plastic litter leakage to the environment, we reviewed the parameters used in the literature and addressed data usability, considering Brazil as a case study. We gathered data on parameters identified for all 5570 Brazilian municipalities and evaluated their usability considering reliability and temporal and geographic granularity. We identified 51 parameters that are either currently used in models or could improve estimates, including parameters regarding territory, population density, socioeconomic condition, and solid waste generation, composition, collection, and final destination, selective waste collection, recycling, and hydrology. Only 29.4% of parameters were linked to data sources with good or very good usability, while most of them presented average usability (45.1%) and 7.8% were not linked to any data source. This panorama of low data usability reveals uncertainties and explicit difficulties of estimating plastic litter leakage to the environment, including mobilization from the terrestrial environment to the ocean. The Brazilian scenario reflects current data availability conditions and the difficulties of countries in the Global South to robustly understand plastic litter leakage and face land-based sources of marine litter.
... To date, estimates of the global yearly MP inputs into the ocean vary from several thousand to a few million tons (Lebreton et al., 2017;Schmidt et al., 2017;van Wijnen et al., 2019;Weiss et al., 2021). The fate of floating MPs upon entering the surface ocean has been studied using Lagrangian models (Maximenko et al., 2012;Sebille et al., 2015), and results showed that they mostly accumulate in the subtropical gyres and along the coasts (Chenillat et al., 2021). ...
... Many factors may influence MP inputs from land to the ocean, and many uncertainties exist in both measurements and modeling of global MP inputs to the ocean. As a consequence, uncertainties in global MP inputs as well as in the global MP budget span several orders of magnitude (see Jambeck et al., 2015;Lebreton et al., 2017;Schmidt et al., 2017;Weiss et al., 2021) and may impact the estimates of MP distribution, residence time, and, consequently, zooplankton exposure. Moreover, a significant fraction of plastic waste found in the ocean may originate from sea-based sources (GESAMP, 2016) and aerosols have also recently been identified as a potential MP source to the ocean (Dris et al., 2018a;Liss, 2020;Brahney et al., 2021;Galgani et al., 2021). ...
... In spite of the recent interest of a wide scientific community for MP research, many questions regarding MP impacts on the ocean remain. These questions span a large range of scientific disciplines such as freshwater and hydrodynamical sciences quantifying MP fluxes from land (e.g., Lebreton et al., 2017;Schmidt et al., 2017;Lebreton and Andrady, 2019;Weiss et al., 2021), atmospheric sciences studying airborne MPs (e.g., Dris et al., 2018b;Evangeliou et al., 2020;Brahney et al., 2021), and physical and biogeochemical sciences quantifying the dynamics and impacts of MPs on ocean nutrient and planktonic cycles (e.g., Kvale et al., 2020). These questions should mobilize a large community of scientists combining methodologies such as experiments, in situ measurements, observations, and modeling in order to build a global understanding of the distribution and impacts of MPs on the ocean. ...
Article
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Microplastics (MPs) are ubiquitous contaminants in the ocean. Zooplankton is thus widely exposed to MP ingestion. Here, we use a global coupled physical–biogeochemical model enriched with a 3D representation of MPs to assess the global zooplankton exposure to MPs. As expected, our results indicate that water MP concentration is the highest in the surface layers of subtropical gyres and coastal areas close to major MP sources, which is mostly due to floating MPs, while neutral MPs contaminate the mesopelagic zone. Additionally, we showed that floating MPs may be also transported to the mesopelagic waters during the seasonal deepening of the mixed layer depth. We then estimate zooplankton exposure to MPs based on water MP concentrations, plankton biomass, and zooplankton grazing rate. Two main drivers lead to high zooplankton exposure to MPs: 1) high water MP contamination and 2) intense grazing activity. Seasonally, re-stratification of surface waters may lead to MP vertical concentration coinciding with planktonic blooms, thus increasing contamination risk.
... Globally, this model estimated the influx of plastic via rivers into the sea to be between 1.15 and 2.41 million tons per year. The second study attempted to find a relationship between plastic waste management and field measurements, estimating a yearly influx between 51,000 tons and 440,000 tons for macroplastics (Schmidt et al., 2017). The total influx of plastics was estimated to be between 1.72 million tons and 4.38 million tons worldwide. ...
... The model of Lebreton et al. (2017) predicts a contribution of the Scheldt River to the plastic influx into the North Sea between 4.2 and 23.3 tons per year, with a peak between January and March. The model of Schmidt et al. (2017) estimates the contribution of the Scheldt River to the macroplastic influx into the North Sea at around 1.46 tons per year. Furthermore, a recent study by Liu et al. (2022) indicated that microplastics in the size range of ≤50-5000 μm were found in all surface waters and sediments collected from 25 sampling sites upstream of Antwerp city and down to the estuary of the Scheldt River. ...
Article
The Sea Scheldt estuary has been suggested to be a significant pathway for transfer of plastic debris to the North Sea. We have studied 12,801 plastic items that were collected in the Sea Scheldt estuary (Belgium) during 3 sampling campaigns (in spring, summer, and autumn) using a technique called anchor netting. The investigation results indicated that the abundance of plastic debris in the Scheldt River was on average 1.6 × 10⁻³ items per m³ with an average weight of 0.38 × 10⁻³ g per m³. Foils were the most abundant form, accounting for >88 % of the samples, followed by fragments for 11 % of the samples and filaments, making up for <1 % of the plastic debris. FTIR spectroscopy of 7 % of the total number of plastic debris items collected in the Sea Scheldt estuary (n = 883) revealed that polypropylene (PP), polyethylene (PE), and polystyrene (PS) originating from disposable packaging materials were the most abundant types of polymers. A limited number of plastic debris items (n = 100) were selected for non-destructive screening of their mineral element composition using micro-X-ray fluorescence spectrometry (μXRF). The corresponding results revealed that S, Ca, Si, P, Al, and Fe were the predominant mineral elements. These elements originate from flame retardants, mineral fillers, and commonly used catalysts for plastic production. Finally, machine learning algorithms were deployed to test a new concept for forensic identification of the different plastic entities based on the most important elements present using a limited subset of PP (n = 36) and PE (n = 35) plastic entities.
... When high production rates and extensive usage of plastics exceed the capacity of the (local) waste management systems, when waste is leaking from dumps or open uncontrolled landfills, or when waste is littered, we refer to it as mismanaged plastic waste (MPW) (Geyer et al., 2017). Each year vast amounts of MPW with a land-based source enter the natural environment, where it is transported across terrestrial systems by aeolian and aquatic processes Schmidt et al., 2017;Barboza et al., 2019;van Emmerik et al., 2019;Materić et al., 2020). It is assumed that MPW generated on land is the main source of riverine and marine plastic pollution (Biermann et al., 2020;Lau et al., 2020;Wayman and Niemann, 2021). ...
... However, several studies suggest that a fraction of the MPW is retained in terrestrial and freshwater systems (Tramoy et al., 2020;van Emmerik et al., 2022). Plastic transport and emission models have been developed over the past years to make an estimate on the amount of MPW that is emitted to the oceans via river emissions Schmidt et al., 2017). These models use estimates of the MPW generation within a river basin and, combined with waste management, population and hydrological related variables, predict the fraction of MPW that is emitted to the ocean at the river mouth. ...
Article
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Land-based plastic waste is the major source for freshwater and marine plastic pollution. Yet, the transport pathways over land remain highly uncertain. Here, we introduce a new conceptual model to forecast plastic transport on land: the Plastic Pathfinder ; a numerical model that simulates the spatiotemporal distribution of macroplastic (>0.5 cm) at a river basin scale. The plastic transport driving forces are wind and surface runoff, while plastic transport is resisted by terrain surface friction. The terrain surface friction, a function of the slope and land use, is converted into thresholds that define the critical wind and surface runoff conditions required to mobilize and transport macroplastic waste. When the wind and/or surface runoff conditions exceed their respective thresholds, the model simulates the transport and (re)distribution of plastics, resulting in plastic accumulation hotspots maps and high probability transport route maps. The Plastic Pathfinder contributes to a better mechanistic understanding of plastic transport through terrestrial environments, and upon future calibration and validation, can serve as a practical tool to optimize plastic waste prevention, mitigation, and reduction strategies.
... Rivers are the main pathways for plastics from terrestrial sources to reach the sea (Lebreton et al. 2017;Zhang et al. 2017), especially through direct discharges (Bellasi et al. 2020). Estimates have indicated that between 0.4 and 0.265 × 10 6 Mg of plastic are introduced into the marine environment through rivers globally every year (Lebreton et al. 2017;Schmidt et al. 2017;Mei et al. 2020). A shorter distance to rivers has been considered one of the main predictors for the prevalence of land-based plastic in marine environments (Schuyler et al. 2021). ...
... Landfills and the margins of the river itself (floodplain) may be sources of MPs for the body of water. Plastic waste deposited along the margins can be introduced into the water column when the level of the water reaches it, which occurs during high-water season (Schmidt et al. 2017), after which the waste is carried to the ocean. Similarly, to the residence time of MPs on beaches (Kataoka et al. 2013;Kataoka and Hinata 2015), the time of debris in diffuse sources is an important parameter that influences the generation of plastic fragments in a watershed (Kataoka et al. 2019). ...
Article
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Plastic pollution can be even more problematic to the environment when this material is fragmented into small pieces forming microplastics (MPs). The objectives of the present study were to investigate the abundance, morphotypes, predominant polymers, and colour of MPs on surface waters, and compare the effect of the hydrologic cycle on the abundance and richness of MP categories along a stretch of the Paraíba do Sul River basin, the water system of which flows through the most populous area in Brazil. Samples were taken from the superficial layer of the water column in high-water and low-water periods 2021, using bottles and plankton net. In total, 15 categories of MP were determined and 290 plastic particles were collected in both periods. A greater abundance of MPs was found during the high-water period than in the low-water period, considering both sampling methods. The MPs in the surface waters of the Paraíba do Sul River are significantly influenced by the rainfall regime. In view of climate change, which encompasses an increase in the frequency and intensity of river floods, our results present significant implications for the management of MPs in riverine and marine systems, within the context of global climatic alterations.
... Much less plastic originates from the ocean, and comes from materials used in the fishing industry, such as fishing gear, rope, or synthetic packaging ( Li et al., 2016 ). Rivers also play a significant role in delivering plastic pollution into the marine environment, by catching variously sized pieces of mismanaged plastics from landbased sources in the catchment area, and transporting them to marine basins even over long distances ( Schmidt et al., 2017 ). Here, wastewater treatment plants can play a particular role, as each day they process large quantities of microplastics, e.g., released from clothes during washing (a single piece of clothing can shed > 1900 microplastic fibers during a single wash) ( Browne et al., 2011 ). ...
... Large micro-/macroplastics were defined as particles > 2 mm, but without an upper size limit. The lower size limit of 2 mm was used for example by Esiukova et al. (2021) to define large microplastics, while macroplastics are often defined as particles > 5 mm (e.g., Schmidt et al. (2017) ). At each site, three separate samples of large micro-/macroplastics were collected at three parts of the beach: driftline, the middle of the beach, and the forehead of the dunes ( Figure 2 ). ...
Article
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The subject of this study was microplastics (>32 µm), large micro-/macroplastics (>2 mm) and plastic litter (visible by naked eye) contamination on sandy beaches and in coastal waters along the Polish coast of the Baltic Sea. Microplastics were studied with particular attention, with simultaneous observations in the water and across the beach. Other data was intended to serve as a background and as possible sources of microplastics. Most of the microplastics found were fibers <1 mm long, with blue fibers dominating, followed by transparent, red and green ones, both in sand and water samples. The concentration of microplastics on the beach sand ranged from 118 to 1382 pieces kg⁻¹, while in coastal waters from 0.61 to 2.76 pieces dm⁻³. As for large micro-/macroplastics and plastic litter, there was no dominant litter along the coast. The amount of large micro-/macroplastics ranged from 2 to 124 pieces m⁻² (or from 0.13 to 44.30 g m⁻²). Regarding plastic litter, on average between 0.03 and 6.15 litter debris m⁻² were found (or from 0.007 to 4.600 g m⁻²). The study confirms that plastic pollution of the Polish coastal zone is a significant problem comparable with both the rest of the Baltic Sea and other seas and oceans. Similar color-based composition of microplastics among all studied sites suggests that they may have a common source, while the contamination of large micro-/macroplastics and plastic litter (both amount of particles and their composition) along the Polish coast is highly site-specific and may be influenced by various local factors.
... As pesquisas sobre a poluição por plástico ganhou grande atenção primeiramente nos ambientes marinhos, entretanto, estudos na última década apontam que estes materiais que chegam ao oceano, são transportados pelos ecossistemas de água doce (EERKES-MEDRANO;ALDRIDGE, 2015, LEBRETON et al, 2017KRAUTH;WAGNER, 2017) e mesmo com a necessidade de mais pesquisas abordando os efeitos que os plásticos podem ocasionar nos ecossistemas dulcícolas, já há evidências que eles são os mais suscetíveis aos danos, devido ao acumulo, e as consequências que este pode gerar para a biota (LI; LIU; CHEN, 2018). Os rios e riachos constituem os ecossistemas mais ameaçados do planeta, devido a uma gama de impactos, que além de desestabilizar seu funcionamento, comprometem a biodiversidade nele presente (FREDERICO, 2018). ...
... As pesquisas sobre a poluição por plástico ganhou grande atenção primeiramente nos ambientes marinhos, entretanto, estudos na última década apontam que estes materiais que chegam ao oceano, são transportados pelos ecossistemas de água doce (EERKES-MEDRANO;ALDRIDGE, 2015, LEBRETON et al, 2017KRAUTH;WAGNER, 2017) e mesmo com a necessidade de mais pesquisas abordando os efeitos que os plásticos podem ocasionar nos ecossistemas dulcícolas, já há evidências que eles são os mais suscetíveis aos danos, devido ao acumulo, e as consequências que este pode gerar para a biota (LI; LIU; CHEN, 2018). Os rios e riachos constituem os ecossistemas mais ameaçados do planeta, devido a uma gama de impactos, que além de desestabilizar seu funcionamento, comprometem a biodiversidade nele presente (FREDERICO, 2018). ...
Chapter
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O consenso entre os cientistas de que o descarte incorreto dos plásticos acarreta diversos prejuízos aos ecossistemas aquáticos, impactando sua biodiversidade trouxe uma corrida a pesquisas para descrever e entender os processos e as consequências destes. O microplástico e nanoplástico chegam aos peixes por meio da respiração, ingestão direta, ou pela ingestão de zooplâncton e de outros organismos. Inicialmente, o foco das pesquisas abordava os ecossistemas marinhos, mas recentemente ampliaram-se as pesquisas com rios, riachos, lagos e reservatórios, já que o ponto inicial de grande parte desse resíduo antropogênico vem dos ecossistemas de água doce. Mesmo com o aumento recente das pesquisas nesses ambientes, o conhecimento sobre as consequências que acarretam ao ecossistema e a comunidade íctica ainda são incipientes. O presente capítulo teve como objetivo realizar uma revisão bibliográfica com foco nas pesquisas com microplásticos na ictiofauna de rios, lagos e riachos, ressaltando os tipos de ambientes mais estudados, as temáticas, os tipos de plásticos e principais impactos relatados. Para esta revisão foi considerado os artigos publicados no período entre em 2010 e 2021, utilizando os principais sistemas de busca voltados para pesquisa científica seguindo critérios pré-estabelecidos. De um total de 144 publicações, somente 16 artigos (11%) foram incluídos, já que atenderam aos critérios de inclusão da revisão, dentre os quais oito (5,5%) foram realizadas no Brasil, destes, 3 foram na Bacia Amazônica, 3 na Bacia do Paraná, 1 na Bacia do São Francisco e 1 na Bacia do Uruguai, compreendendo 4 estudos realizados em rios e 4 em riachos. A maioria dos estudos avaliou o trato gastrointestinal, havendo a necessidade de pesquisas voltadas para análise do arco branquial da ictiofauna. Além disso, deve ser ressaltado o pequeno número de publicações tanto em escala mundial como no Brasil, e a ausência de trabalhos nas Bacias do Parnaíba, Tocantins e Paraguai. Dada a crescente necessidade de fazer avaliações comparativas para identificar tendências regionais, nacionais e globais na distribuição de nano e microplásticos nos ecossistemas de água doce e na ictiofauna, isso se torna um grande desafio, pois, embora muitos estudos utilizem técnicas amplamente aceitas e semelhantes, ainda não existe um protocolo padronizado e as pesquisas são restritas a verificar a presença e não estabelece relações com as concentrações ou com os habitats mais susceptíveis, ou gradientes longitudinais ou verticais ao longo de rios e lagos.
... The United Nations has declared plastic pollution as one among the critically emerging environmental issues of our times [40]. The major share (nearly 80%) of plastic waste in the ocean is carried there by rivers [41,42]. Only 13% of studies focus on plastic pollution in the freshwater environment [43]. ...
... At the next level, van Wijnen et al. (2019) predicted that if the present scenario of plastic waste management practices (which are less efficient in the removal of MPs) continues then these plastic transport through rivers could increase 50% by the year 2050. Furthermore, Schmidt et al. (2017) also envisage, based on modelling that there may be a reduction of 45% plastic load to seas by rivers, if the transfer of this botched plastic discard is reduced by 50% in the top 10 polluted rivers. ...
Article
There is an emerging concern about the accumulation of MPs in aquatic ecosystems. In this context as compared to the study of marine environment the freshwater environment has not yet been explored. Microplastics have become an emerging hazard to the natural environment and humanity, which can now be frequently found in different aquatic bodies. Due to their pervasive occurrence in the environment, it can impose severely negative impacts on aquatic organisms. Microplastic particles can also associate with other pollutants like metals and different organic pollutants, which further increase their toxicity. Riverine systems are the most important transporters of these materials from terrestrial to marine environments. It is documented that amongst the rivers, Yangtze (China) contributes the highest plastic litter discharge followed by the Indian, Ganges to the marine environment. In India, scanty data are available on MPs contamination in freshwater environs and it was found that more weightage has been given to the marine environment of east and west coastal regions. Therefore, this paper aims at reviewing the existing as well as current research progress on the abundance, distribution, toxicity, and effects of MPs pollution in the riverine ecosystem in India.
... However, it is well recognized that the mass of plastics accumulated at the surface of oceanic subtropical gyres like the NPGP represents only a small fraction of the global plastic emissions into the marine environment. With recent studies estimating up to several million tonnes of mismanaged plastic waste entering the world's oceans from coastal cities 4 and rivers worlwide [5][6][7][8] every year, the larger part is believed to be predominantly accumulating on shorelines [9][10][11][12][13] or on the seabed in proximity to landmasses [14][15][16][17] . ...
Article
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The subtropical oceanic gyre in the North Pacific Ocean is currently covered with tens of thousands of tonnes of floating plastic debris, dispersed over millions of square kilometres. A large fraction is composed of fishing nets and ropes while the rest is mostly composed of hard plastic objects and fragments, sometimes carrying evidence on their origin. In 2019, an oceanographic mission conducted in the area, retrieved over 6000 hard plastic debris items > 5 cm. The debris was later sorted, counted, weighed, and analysed for evidence of origin and age. Our results, complemented with numerical model simulations and findings from a previous oceanographic mission, revealed that a majority of the floating material stems from fishing activities. While recent assessments for plastic inputs into the ocean point to coastal developing economies and rivers as major contributors into oceanic plastic pollution, here we show that most floating plastics in the North Pacific subtropical gyre can be traced back to five industrialised fishing nations, highlighting the important role the fishing industry plays in the solution to this global issue.
... When rivers flow through urban centers, effluents from plastic-related industries, and some other sewage spill into them, MPs waste in the aquatic ecosystem is highly tied to the terrestrial ecosystem (Wong et al., 2020). The quantity of plastic garbage produced in the upstream drainage basin has been proven to have a positive link with the plastic concentration found in the river (Lebreton et al., 2017;Schmidt et al., 2017). Plastic pollutants can be traced back to urban areas (Luo et al., 2019). ...
Article
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Microplastics (MPs), a small piece (<5mm) of plastic debris, are amongst the most serious threats to aquatic ecosystems. These are commonly found in aquatic environments due to the widespread use of plastic items. Plastic components are broken down from the large fragments into small fragments during the treatment procedure in treatment plants of wastewater, these plants can operate as the entry points for the MPs into the aquatic ecosystem; so it is necessary that MPs must be removed from the wastewater during the treatment process. However, there is not sufficient data available about MPs' impact on the ecological services cascade and how it is linked with the declining biodiversity. This review examines the outcomes of MPs in the aquatic environment, their role as carriers, and the possible influence of MPs on aquatic biota. In this review detailed overview of existing knowledge regarding MP aggregation in the aquatic ecosystem is provided.
... This is due to accidental losses during handling, transport and discharges of wastewater, either directly into the sea or indirectly when they are transported along with watercourses eventually flowing into the ocean [4,10,11]. Rivers represent one of the largest sources of plastic debris to the oceans-it is estimated that only 10 top-ranked catchments discharge between 88% and 94% of the total oceanic plastic load [12]. Furthermore, due to ineffective waste management, plastics accumulate in the environment and eventually give rise to secondary microplastics [13]. ...
Chapter
Widespread contamination with microplastics (< 5 mm, MPs) has become an emerging global problem. Airborne microplastics and synthetic fibres contaminate the air we breathe, but their concentrations are highly influenced by sampling and analytical methodologies. This chapter reviews current pre-treatment and characterization techniques applied to airborne MPs. Pre-treatment of samples removes unwanted materials and selects MPs, avoiding interference from organic and/or inorganic materials. Identification or characterization of plastics is mostly based on visual identification, followed by spectroscopy methods. Additionally, great care must be taken regarding the cross contamination of samples with deposited microplastics originating from the laboratory air. It is urgent to define a validated standard protocol, which will contribute to a better understanding of sources and concentrations of airborne microplastics in the environment.
... In addition to news about the impacts of plastic on the marine ecosystem, scientific estimations of plastic leakage into oceans have raised awareness. Jambeck et al. (2015) estimate 4.8¬ million-12.7 million tonnes of plastic are discharged into oceans annually, and other researchers also estimate leakage from rivers to oceans (Borrelle et al., 2020) and leakage to rivers, lakes and oceans (Lebreton et al., 2017;Schmidt et al., 2017;Meijer et al., 2021). For example, plastic leakage from ASEAN countries accounts for 56.8 percent of global leakage (Meijer et al., 2021), which means ASEAN is a major source of plastic leakage into oceans. ...
Technical Report
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Policy Brief of T20 Indonesia 2022 Task Force 3 Governing Climate Targets, Energy Transition, and Environmental Protection. https://www.t20indonesia.org/wp-content/uploads/2022/09/PB-12-Layouted.pdf
... Increasing unplanned urbanization, coupled with modern lifestyles is estimated to escalate the water demand to 55%-60% (IUCN, 2013) by 2050 for the 10 billion projected population. Wastewater from various sources has been reported to be contaminated by multiple pollutants such as nutrients (Van Puijenbroek et al., 2019), pathogens (Vermeulen et al., 2015;Hofstra and Vermeulen, 2016) from human excretion, plastics (Avio et al., 2017;Boucher and Friot, 2017;Lebreton et al., 2017;Schmidt et al., 2017;Siegfried et al., 2017), and chemicals from personal care products (Diamond and Cohen, 2018;Van Wijnen et al., 2019). Clean drinking water and sanitation are not available to billions of people, particularly in rural areas. ...
Article
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The increasing amount of sewage has become a serious concern globally, demanding sustainable solutions. The constructed wetland system (CWS) can be installed at the wastewater discharge site and properly screened bio-purifiers can be used for efficient wastewater treatment. Filter-feeding zooplankton have the potential to graze on bacteria and reduce biological oxygen demand. However, higher suspended particles choke the zooplankton filtering appendages. An integrated application of zooplankton and macrophytes can solve the problems by reducing contaminants and providing the surface area for zooplankton to take refuge. Using three different approaches: (a) screening of natural bio-purifiers through time series study, (b) assessment of sewage treatment potential of screened bio-purifiers in the CWS and, (c) evaluation of the growth potential of screened bio-purifiers in untreated wastewater, this study explored the combined use of macrophyte and zooplankton in the CWS. The 3-year time series study in the vicinity of the wastewater discharge area recorded the zooplankton, Brachionus angularis and Moina macrocopa as highly indicative zooplankton. The top two highly indicative macrophytes are Typha and Phragmites. Under laboratory conditions, the population growth rates of B. angularis and M. macrocopa were significantly higher in wastewater without any external nutrient source than those in control with algae as a food source. The integrated application of zooplankton (B. angularis and M. macrocopa) macrophytes (Typha and Phragmites) in CWS yielded upto 56% reduction in the total bacterial count and upto 92% reduction in BOD along with substantial increase in the DO level. The present results strongly suggested the use of CWS planted with macrophytes and inoculated by zooplankton. The usefulness of this system is further supported by the natural occurrence of selected species, as it is easy to maintain, has low installation cost, and excellent efficiency in treating wastewater. As both the zooplankton species are preferred live feed for rearing of fish larvae, the present results suggested the use of zooplankton and macrophytes for treatment of wastewater, reduction of sludge, and harvest of live feeds for the aquaculture industry to augment circularity and promote decentralized wastewater treatment.
... The impact of plastics in aquatic systems is increasingly assessed, but the focus has largely been on marine systems (Blettler et al., 2018). However, research on plastic in riverine systems is also important because of direct effects as well as its contribution to the pollution of the oceans, functioning as pathways for land-based plastics (OSPAR, 2017;Schmidt et al., 2017). Yet, detailed knowledge of transport processes of plastics in rivers is limited but see Tramoy et al. (2020) and Newbould et al., 2021. ...
Article
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Riverine systems are directly affected by plastic pollution and function as pathways for plastic transport to the sea. Plastic litter can enter the water by remobilization from the bed or from the riverbank, after which it can be transported with the flow. The process of remobilization is still poorly understood. To get a detailed understanding of the role rivers play in plastic transport and hence develop management measures to prevent or mitigate plastic transport it is vital to get a fundamental understanding of the factors contributing to remobilization of plastic on the riverbank. Therefore, we investigated how the wave action of inland navigation, one of the dominant actors in anthropogenic rivers, affects the remobilization of land-based plastics. Quantification of remobilization was performed along the riverbank of an intensely navigated river in the Netherlands (the river Waal) allowing for a real-world assessment of remobilization. Plastic pieces were placed at standardized distances from the average waterline to determine the plastic remobilization along the riverbank at different locations. Subsequently, wave actions of passing inland navigation was used to assess plastic remobilization. Inland navigation induced wave action was found to significantly cause remobilization of plastics present on the riverbank. The distance of the plastic object to the waterline combined with the wave height, riverbank slope and plastic size significantly affected remobilization probability. Overall, the remobilization effect was strongest on plastics present within ≤ 1.0 m from the waterline. With a wave height ≥ 0.5 m all plastics present up to 3.0 m from the waterline were remobilized and thereby potentially transported downstream through the river.
... Lebreton et al. (2017) estimated that 1.15 to 2.41 MMT of plastic waste enter the ocean every year from inland areas (>50 km upstream) via river transport. Another study on riverine plastic exports generated similar results, estimating that 0.47 to 2.75 MMT of plastic are deposited in the ocean from rivers every year (Schmidt et al., 2017). ...
Article
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Land-based sources of litter are increasingly recognized as significant contributors to marine debris, and rivers can carry debris to the coast from far-inland sources. In this paper, we demonstrate the important role inland cities can play in the marine debris crisis by reducing their own marine debris contributions. Given this role, we provide a framework for inland cities to prevent plastic pollution along with the lessons learned from introducing these strategies in Durham, North Carolina, a mid-sized, inland city that drains to the ocean through the Cape Fear and Neuse River watersheds. This framework guides city officials, resource managers, and community partners on how to characterize the plastic pollution problem in their city by collecting baseline data on plastic waste and litter. This framework also provides practical and equitable solutions for inland cities to address plastic pollution. We recommend that inland cities prioritize policy solutions that reduce waste at the source – to the extent that their state constitutions allow – and to also use authorities for stormwater controls to capture and remove debris as long as litter persists. Replicating this framework in other inland cities opens vast opportunities to manage and reduce marine debris from an often-overlooked source.
... Plastics can enter riverine systems through natural processes, for example wind and surface runoff, or via direct dumping of waste into the rivers themselves. Over 1,300 rivers are thought to make up over 80% of these inputs (Meijer et al., 2021), a significantly higher number than the previously reported 20 rivers accounting for 67% of the global total (Lebreton et al., 2017;Schmidt et al., 2018). Export of plastics from rivers (in particular estuaries and rivers with low freshwater discharge) will be temporally variable, due to the tidal ebb and flow causing bidirectional transport of plastic debris (van Emmerick et al., 2020). ...
Thesis
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Plastic pollution is ubiquitous within the marine environment, found on coastlines, at the sea surface, within the water column, on the seafloor, in deep-sea sediments, and in sea ice at both Poles. However, the transport pathways and processes that determine the three-dimensional distribution of plastics in the global ocean are still not yet fully understood. In this thesis, the three-dimensional distribution of plastics is investigated using an ocean general circulation model, in a range of different scenarios. Firstly, the distribution of positively, neutrally, and negatively buoyant plastics in the global ocean with no processes of removal is explored. This reveals that plastics of different densities inhabit different regions of the ocean: buoyant plastics reside at the sea surface in subtropical gyres, with model results suggesting the possibility of an unreported ‘garbage patch’ in the Gulf of Guinea; neutrally buoyant plastics are present throughout the whole of the water column; negatively buoyant plastics sink and settle coastally, but are also transported to abyssal plains and trenches. Secondly, the accumulation and transport of microplastics in sea ice, in both the Arctic and Southern oceans is investigated. Arctic sea ice is most susceptible to buoyant microplastic pollution, with a predicted distribution reflecting observations, whereas Southern Ocean sea ice is more susceptible to neutrally buoyant microplastics, although observational evidence is too limited to validate these results. Finally, building upon existing modelling research, the effects of biofouling on the vertical and horizontal distribution of a range of small microplastics, both with and without the effects of strong vertical mixing are considered. The impact of density changes caused by biofouling are size-dependent and independent of vertical mixing, with 10 μm microplastics most affected by biofouling in the model. However, this is a complex problem with many variables to consider and requires further, detailed research. While this thesis has shed light on some aspects of the subject of marine microplastics, there are still significant gaps in our knowledge of the global distribution and behaviour of marine plastics.
... However, plastic waste transforms into microplastics (MPs) over time in the environment and MPs are an emerging problem of concern because of their ubiquity, persistence and potential hazard to ecosystems and human health (de Souza Machado et al., 2018;Schmidt et al., 2020;Kim et al., 2022). It is estimated that there are about 4.85 trillion MP particles (<5 mm) in the oceans and this is increasing as rivers alone transfer 0.47-2.75 million tons of MPs to the marine ecosystems every year Lebreton et al., 2017;Schmidt et al., 2017). Even though rivers play a significant role in distributing MP pollution to marine environments (Jambeck et al., 2015;Lebreton et al., 2017), until recently little attention was given to rivers, although, this appears to be slowly changing (Lebreton et al., 2017). ...
... Besides the fluvial transport of plastic waste and MP, there is little known about MP in freshwater systems, compared to the knowledge about marine areas. Although about 80% of the plastic is estimated to derive from the terrestrial areas and rivers are dominant pathways for MP [1,10,14,20,21]. So far, most of the studies conducted in the freshwater environment have focused on the occurrence of plastic debris on the water surface, while sediments were hardly examined [22][23][24][25]. ...
Article
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The African continent is rarely the focus of microplastics research, although the ubiquity of microplastics in the environment is undisputed and still increasing. Due to the high production and use of plastic products and the partial lack of recycling systems in many parts of the African continent, it can be assumed that microplastic particles are already present in limnic and terrestrial ecosystems. Few studies, mainly from South Africa and the Northern African region, show a contamination with microplastics, especially in marine environments. This study aims to explore the presence and composition of microplastics in fluvial sediments of the major catchments in Namibia with a regional focus on the Iishana system in Northern Namibia, as one of the most densely populated areas in the country. In March 2019 and March 2021, at the end of the rainy seasons, sediments from the Iishana system and of the largest river catchments were sampled. Extraction was performed by density separation using the Microplastic Sediment Separator (MPSS) with the separation solution sodium chloride (density of 1.20 g/cm³). The particle size was determined by filtration and fractionation, and the polymer type by measurement with ATR-FTIR spectroscopy (minimum particle size 0.3 mm). Microplastics were found in the sediments of each river system, most of the particles in the Iishana system (average of 13.2 particles/kg dry weight). The perennial, the ephemeral rivers, and the Iishana system are similar concerning polymer type and particle size. Polyethylene and polypropylene were the dominant polymer types. Most of the particles were found in the size fractions 0.3 – 0.5 mm and 0.5 – 1.0 mm. The particles were found mainly as fragments and films, the majority transparent and brown.
... Although Smith & Smith (1998) described plastic debris as a growing threat, there has since been limited progress in understanding risks. Recent studies have identified the presence of plastics in dolphin habitats (Schmidt et al. 2017, Li et al. 2018, Rodrigues et al. 2019, Aliaga-Rossel & Guizada 2020. One study concluded that the risk of entanglement of Ganges river dolphins from ghost nets is high (Nelms et al. 2021a). ...
Article
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River cetaceans are particularly vulnerable to anthropogenic impacts due to their constrained ranges in freshwater systems of China, South Asia, and South America. We undertook an exhaustive review of 280 peer-reviewed papers and grey literature reports (1998−2020) to examine the current status of knowledge regarding these cetaceans and their conservation. We aimed to better understand the scale of threats they face, and to identify and propose priority future efforts to better conserve these species. We found that the species have been studied with varying frequency and that most of the research on threats has focused on habitat degradation and fragmentation (43%, mainly driven by dams and extractive activities such as sand mining and deforestation), and fishery interactions (39%, in the form of bycatch and direct take). These threats occur across all species, but more information is needed, primarily on quantifying the population impacts as a basis for designing mitigation measures. Other threats identified include pollution, vessel collisions, traditional use, and poorly managed tourism. Emerging methods such as environmental DNA and unmanned aerial vehicles are described for studying these species. Promising conservation interventions include cetacean-specific protected areas, natural ex situ protection, community-led conservation, and education programmes. However, transnational political will is required for a step change towards broad-scale protection in freshwater environments. In addition, we propose in creasing capacity building, developing management plans, working closely with fishing communities, enhancing public awareness, expanding regional collaborations, and diversifying funding.
Article
The quantification of macroplastic fluxes transferred by rivers toward the pelagic environment requires a better understanding of macrodebris transfer processes in estuarine environments. Following the strategy adopted in the Seine estuary, this study aims to characterize macroplastic trajectories in the Loire estuary. Between January 2020 and July 2021, 35 trajectories were monitored using plastic bottles equipped with GPS-trackers. With total travelled distances between 100 m and 103.6 km, trajectories show great spatiotemporal variability. The various forcing factors (macroplastic buoyancy, estuaries tidal and hydrometeorological conditions, geomorphology and vegetation) lead to chaotic trajectories, preventing accurate predictions in macroplastic transfer and storage/remobilization dynamics. In the Loire estuary like in the Seine one, no tracked bottle reached the Atlantic Ocean. It confirms that macrotidal estuaries under temperate climates constitute accumulation zones and slow pathways for macroplastics, but raises question on the real fluxes transferred from continental areas to oceans.
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At present, the distribution of plastic debris in the ocean water column remains largely unknown. Such information, however, is required to assess the exposure of marine organisms to plastic pollution as well as to calculate the ocean plastic mass balance. Here, we provide water column profiles (0–300 m water depth) of plastic (0.05–5 cm in size) concentration and key planktonic species from the eastern North Atlantic Ocean. The amount of plastic decreases rapidly in the upper few meters, from ~ 1 item/m ³ (~ 1000 µg/m ³ ) at the sea surface to values of ~ 0.001–0.01 items/m ³ (~ 0.1–10 µg/m ³ ) at 300 m depth. Ratios of plastic to plankton varied between ~ 10 –5 and 1 plastic particles per individual with highest ratios typically found in the surface waters. We further observed that pelagic ratios were generally higher in the water column below the subtropical gyre compared to those in more coastal ecosystems. Lastly, we show plastic to (non-gelatinous) plankton ratios could be as high as ~ 10 ² –10 ⁷ plastic particles per individual when considering reported concentrations of small microplastics < 100 μm. Plastic pollution in our oceans may therefore soon exceed estimated safe concentrations for many pelagic species.
Article
Microplastics (<5 mm) are an emerging pollutant which have received increasing concern in recent years. Microplastics pose a serious hazard and potential risk to the environment due to their migration, transformation, adsorption and degradation properties. The effects of different types of microplastics on the elemental cycles (carbon, nitrogen and phosphorus cycles) in ecosystems were comprehensively summarized. The impacts of microplastics on the element cycle occur mainly in the soil environment and to less extent in other environments. Microplastics affect carbon sources, carbon dioxide (CO2) emissions, and carbon conversion processes, mainly by affecting plant and animal activities, changing gene abundance, enzyme activity, and microbial community composition. Microplastics can affect nitrogen sources, nitrogen fixation, ammonification, nitrification and denitrification processes by changing gene abundance, enzyme activity and microbial community composition. Microplastics can also influence phosphorus content and phosphorus conversion processes by stimulating enzyme activity and changing the composition of microbial communities. Future research needs to analyze the coupling of multiple microplastics and influencing factors on elemental cycling processes. This work provides a better view of the impacts of microplastics on element cycles and the interaction between microplastics and organisms.
Thesis
D’après la littérature scientifique, les plastiques présents en mer libèrent des micro et nano-plastiques ainsi des substances chimiques, potentiellement transférées ou bioaccumulées dans les organismes marins, ce qui constitue une source potentielle de préoccupation. Par ailleurs, l’aquaculture marine utilise de nombreux équipements en plastique, devant être recyclés en fin de vie (cf. Directive (UE) 2019/904). Dans ce contexte, tout nouvel équipement en plastique conçu pour l’aquaculture doit être éco-conçu et s’inscrire dans une économie circulaire. Le présent travail propose une méthodologie d’éco-conception, systémique et pilotée par l’usage, développée pour maîtriser l’innocuité, la durabilité et la recyclabilité des matériaux polymères utilisés en aquaculture, et comprenant 4 étapes : 1- une évaluation scientifique des risques liés à l’usage du matériau, 2- l’identification des points de contrôle de ces risques, 3- le développement d’actions préventives, 4- la définition de procédures de vérification de leur maîtrise, incluant la réalisation d’analyses biométriques et chimiques dans le cadre d’une expérimentation in situ.
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Plastic pollution in the ocean primarily originates from the land-derived mismanaged plastic waste that is transported by rivers. This study aimed to estimate the plastic litter generation in the surface water in Jakarta and Indonesia. A field survey was conducted at six riverine sampling points (upstream to downstream) and three holding facilities of the litter in Jakarta during the rainy season. The Jakarta Open Data database was used to estimate the tonnage of plastic litter. By mass, plastic comprised approximately 74 % of the anthropogenic litter in rivers and 87 % in holding facilities. The riverine plastic proportion slightly increased downstream. Approximately 9.9 g/person/day of plastic litter was discharged into Jakarta's surface water during rainy season and recovered by floating booms. To reduce plastic pollution and its severe impacts on aquatic ecosystems and human health, further field investigation is necessary to design an effective clean-up system and litter-prevention strategy.
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The study focuses on analyzing the presence and quantity of microplastics near an unscientific solid waste dumping site located at Kochi city in India and thereby assessing the contribution of massive open dumping towards microplastic pollution in the river. Two sets of sampling with three sediment samples from nearby Kadambrayar river and five topsoil samples from various parts of the Brahmapuram waste dumping yard were carried out during January – February 2019. The samples were analyzed as per the US National Oceanic and Atmospheric Administration (US NOAA) protocol. ATR-FTIR and DSC analysis based characterization indicated that polyethylene dominated the micro plastics followed by polypropylene and polystyrene. The size distribution of particles showed that comparatively larger particles of size range between 2.36 − 4.75 mm were present in the topsoil than that in river sediments which had more number of particles in size range below 2.36 mm. The study confirmed the presence of an average of 100 microplastic pieces per 100 gram of sediments of Kadambrayar river bordering the waste dumping yard at Brahmapuram. The topsoil of Brahmapuram waste dumping yard was found to contain 178 pieces of microplastics per 100 gm of soil. Microplastics are found to be high in the river stretch near the open dumping site which has a significant role in the pollution, causing a major threat to the entire ecosystem.
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Botswana is concerned about the continuously escalating failure rate of children in basic education [grades 1–12], despite the introduction of technology in some schools. The efforts made have no significant change in the performance of children in schools. Basarwa and Bakgalagadi children l¦ive in abject poverty and rely solely on government’s handouts such as food baskets. Inequality and extreme poverty are prevalent in both rural and urban areas. The Basarwa and Bakgalagadi in the Kgalagadi desert have no opportunities for employment or resources they can utilize to change their economic status. The Kgalagadi areas are rich in wildlife, but there is no economic gain from the available natural resources and most of their basic needs are provided for by the government. The culture of the Basarwa is unique in that they speak various indigenous languages and are a very closely-knit ethnic group. Some children leave boarding schools to return home to their parents because they miss their families, and this affects their performance. Most of the Basarwa and Bakgalagadi parents are illiterate and do not value education. Factors leading to poor performance have been established. This study utilized qualitative research methods in one Basarwa settlement area as a case study to establish why Basarwa children failed to complete their education.
Article
Weiss et al. (Reports, 2 July 2021, p. 107) incorrectly conclude that the residence time for floating microplastic stock at the ocean surface is ~2.4 years. We contend that this conclusion is fundamentally flawed, because the residence time is obtained through dividing a published oceanic stock of plastic debris by a doubtable river microplastic flux estimated by the authors.
Article
Traditionally, toxicity of microplastics is ascribed to the chemicals adsorbed on them. However, microplastics can also interact with biomolecules, such as secretory proteins from aquatic organisms, and form protein-coated microplastics corona complex with unknown toxic effects. Here, we investigated the toxic effects of polystyrene microplastics (PS) and bovine serum albumin (BSA) coated PS corona complex (PS + BSA) on adult zebrafish (Danio rerio) intestines. The food intake ratio, accumulation and distribution of microplastics, histopathological changes, and molecular effects related to the antioxidant system in the intestine were studied. For the first time, we observed that PS + BSA aggregated on the inner surface of the zebrafish intestine, whereas PS dispersed. The aggregation of PS + BSA resulted in increased microplastics accumulation and longer residence time in the zebrafish intestine, which inhibited food intake and generated reactive oxygen species (ROS) in the intestine. Furthermore, the functions of the Keap1-Nrf2-ARE antioxidant signaling pathway and the activation of antioxidant enzymes were significantly affected by PS + BSA after a 21-day exposure. Ultimately, a higher accumulation of ROS and stronger inhibition of antioxidants led to more severe intestinal injury. These results suggest that the increased toxicity of protein-coated microplastics corona complex may be affected by oxidative damage and can result in the inhibition of digestion due to their aggregation and longer residence time in the intestine. Therefore, the ecological risk of microplastics may be underestimated owing to the interactive mechanisms of microplastics and protein coronas.
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Although the discovery of plastic in the last century has brought enormous benefits to daily activities, it must be said that its use produces countless environmental problems that are difficult to solve. The indiscriminate use and the increase in industrial production of cleaning, cosmetic, packaging, fertilizer, automotive, construction and pharmaceutical products have introduced tons of plastics and microplastics into the environment. The latter are of greatest concern due to their size and their omnipresence in the various environmental sectors. Today, they represent a contaminant of increasing ecotoxicological interest especially in aquatic environments due to their high stability and diffusion. In this regard, this critical review aims to describe the different sources of microplastics, emphasizing their effects in aquatic ecosystems and the danger to the health of living beings, while examining, at the same time, those few modelling studies conducted to estimate the future impact of plastic towards the marine ecosystem. Furthermore, this review summarizes the latest scientific advances related to removal techniques, evaluating their advantages and disadvantages. The final purpose is to highlight the great environmental problem that we are going to face in the coming decades, and the need to develop appropriate strategies to invert the current scenario as well as better performing removal techniques to minimize the environmental impacts of microplastics.
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This chapter presents information on how plastic pollutants are transported in and by the lithosphere, hydrosphere, biosphere, and atmosphere to reach stratospheric heights and abyssal depths and from trophic coasts to remote polar regions. Only recently, studies on the mechanisms and modes of transport of plastics have gained momentum, and the available results indicate that plastics behave similarly to other types of sediments, and their transport is also governed by physical, chemical, and biological processes. Transportation of plastic pollutants in the natural environment is affected by all the natural agents such as gravitational, glacial, aeolian, fluvial processes and coastal and deep marine waves and currents that are energized by intrinsic and extrinsic factors. Superimposed on these are the interferences from anthropogenic activities.KeywordsModeMechanismPathwayEnvironmental distributionSorbentSorbateSourceProvenanceSupraglacial debrisAbyssal depthPolar regionSubaerial transportBuoyancySurface transportSnowingRainingSurface runoffOceanic currentGeostrophic circulationAgents of transport
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Microplastics (MPs) and nanoplastics (NPs) are becoming a worldwide concern. The ubiquitous dispersion of MPs/NPs in both terrestrial and aquatic environments is growing because of increase in the production and use of plastics globally. Freshwater systems such as lakes and rivers facilitate the transport of plastic particles from urban to marine environments. The presence and potential ecotoxicological effects of MPs in freshwater systems are not clearly understood. The co-occurrence of MPs/NPs with other biological and chemical contaminants such as pathogenic microorganism or heavy metals adds higher complexity to this rapidly growing pollution. Tracking and identification of the fate of plastic debris in freshwater is critical to development of mitigation strategies. In this chapter, the occurrence and sources of MPs/NPs in freshwater ecosystems are summarized. Mass flow, global river, and spatiotemporally explicit models are discussed. These can complement the information on tracking and fate of these particles and help understand these systems better. In addition, interactions of plastic particles with the microbial communities affecting the biofilm formation and biodegradation process are reviewed. As the water cycle is site specific, interconnected, and its components have similar dynamic environment, presenting global freshwater-specific information is challenging. We tried our best to highlight the important role of freshwater system with regards to MP/NP pollution.
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China is one of the largest waste importers and producers in the world, with land-based discharges mainly from domestic sewage and industrial wastes being the main source of marine debris (MD) including three distributional types as stranding on the beach (BMD), floating on the water surface (FMD), and submerging into sediments (SMD). Fishery-related activities are also one of the main sources of marine debris: intensive aquaculture, fishing, and related household activities. Marine debris, showing different ways of leaching, degradation and fragmentation, can be ingested, incorporated and accumulated by marine organisms through the food chain, and ultimately pose risks to the ecological environment, economic benefits and human health. Comprehensive countermeasures, from awareness to practices and from the government to the public, are now being implemented in China and have achieved remarkable results especially in domestic waste incineration, but greater commitment and stronger execution are urgently required.
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Large‐scale production and use of plastics began around 1950, and since then they have become increasingly ubiquitous materials due to their combination of useful properties, including cost‐effectiveness, low density, ease of processing, water‐resistance, and durability. Microplastics in environmental samples are frequently categorized in terms of their chemical identity, color, and morphology. Despite improvements in recycling technology, the plastics economy is largely linear; some plastics are unsuitable for recycling, many plastic items are improperly disposed of by users, either as litter or into incorrect waste streams, and potentially recyclable plastic waste is sent to landfill or discharged to rivers and oceans on enormous scales. water treatment plants are significant point sources of microplastic contamination into the aquatic environment, deriving from sources including fibers and fragments of artificial textiles in washing machine run‐off, and particles from tire wear and other plastic fragments on urban surfaces.
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Micro‐ and nanoplatics have been already reported to be potential carcinogenic/mutagenic substances that might cause DNA damage, leading to carcinogenesis. Thus, the effects of micro‐ and nanoplastics exposure on human health are currently being investigated extensively to establish clear relationships between those substances and health consequences. So far, it has been observed that there exists a definite correlation between exposure to micro‐ and nanoplastic particles and the onset of several cancers. Therefore, we have conducted research using PubMed, Web of Science, and Scopus databases, searching for all the research papers devoted to cancers that could be potentially related to the subject of exposure to nano‐ and microplastics. Ultimately, in this paper, we have discussed several cancers, including hepatocellular carcinoma, pancreatic cancer, pancreatic ductal adenocarcinoma, biliary tract cancer, and some endocrinerelated cancers.
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From the environmental perspective, efficient plastic utilization and its recyclability become significant issues that need to be resolved for deploying urban and sustainable technologies. It is estimated that approximately 400 million tons of plastic are produced each year for different applications. This number will be doubled by 2050, which is a serious problem. The primary issue that arises in a recycling process is associated with optimum supply chain management. The comprehensive and transparent supply chain methodologies will help stockholders to make conclusive policies and precise strategies. Transparency in supply chain management assists in captivating planning, pricing, purchasing, and inventory management decisions. Environmental sustainability requires recycling, which should have innovative concepts like Artificial Intelligence (AI) and Block‐chain Technology. Manual methods of sorting and segregating the waste have outdated and not much efficient. The inclusion of AI and Blockchain Technology brought a revolution by increasing the efficiency and accuracy of the recycling process. This critical review focused on recycling plastics and plastic waste using AI and Blockchain Technology. Various plastic regulation policies and AI utilization for plastic recycling are discussed. An overview of the blockchain and its classification for waste management or plastic recycling has been discussed. The utilization of Blockchain Technology for a plastic circular economy, its types, and critical benefits has also been systematically demonstrated.
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Many studies focus on the transport of plastic from rivers to oceans while little attention was paid to the plastic transport in the upper reaches of rivers. Transport process of plastic from upstream to downstream in the whole river basin scale is still poorly understood. In this work, five sections in the upper reaches of the Yangtze River were investigated to characterize the features of plastic transport. Plastic abundance and flux were 293 to 156,667 n/m³ and 1.2 to 34,711 g/s, respectively. Plastic flux peaked at or right after the first flood peak in most sections, but plastic abundance was the highest in the normal or low water period. The first flood peak caused a temporary rise of plastic flux that last a short duration. Transport of plastic was not limited to water surface, and the Three Gorges Dam showed a peak elimination effect on plastic transport. Annual discharge of plastic was 1392 to 9532 tons and 6.2 × 10¹⁴ to 175 × 10¹⁴ particles at different sections. An increasing trend was observed for both plastic mass and quantity going downstream. Results showed that river plastic flux is highly variable and influenced by the dam, which should be considered in future to develop better monitoring strategies and to further improve the model.
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Diverse litter studies on Colombia's Central Caribbean Coast have presented the Microplastic issues regarding typology, magnitudes, and distribution. No studies have examined MPs' presence and abundances in relation to sediment grain size and the sediments statistical parameters (mean, median, sorting, skewness, kurtosis). This work attempts to fill this information gap in a study of 15 sampling sites along Colombia's Central Caribbean Coast. Sediment samples were collected and analysed to determine sediment granulometric properties, in association with the presence, magnitudes, shapes, and impact of MPs, and their possible relationships. Within the study area, grain size distribution was similar between surveyed sites, with a dominance of three textural groups: sands, slightly gravelly sands, and slightly gravelly muddy sands. In terms of size-sorting categories, the percentages were moderately well sorted (60 %), moderately sorted (20 %), well sorted (13 %), and very well sorted (7 %). Microplastic abundances (densities) ranged from 160 to 1120 MPs/kg, similar to other global beaches. Microplastic fibers were the dominant typology at 86.8 % of the combined beaches total. Multiple linear regression analysis suggested that approximately 30 % of the MPs' presence could be related to changes in the five sediment statistics used in this work, being the most important statistical parameter sorting with 11 % (r2 = 0.27 - F-Statistic = 0.67). To manage the MP issue, reducing the current elevated plastic inputs into the environment is necessary/mandatory. Approaches to reach this goal must be focused on the entire plastic life cycle (extraction, design, production, use, disposal, recovery, recycling).
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This chapter introduces the readers to the origin, production statistics, and growth history of plastics as environmental menace that has outgrown its utilitarian value. Plastics are in use in almost every sphere of human habitat that in turn has driven their demand, leading to exponential growth in production, a dominant quantity of which end up as a modern environmental menace. Plastics are fabricated from polymer chains produced from monomers such as fossil fuels or biomass. Though the first synthesis of plastic was made in the year 1869, it was not until the discovery of nylon in the year 1935 that man-made polymer production skyrocketed. From 2 million metric tons (MMT) of production during the 1950s, the production of plastics was increasing steadily at a rate of 8% per year, and it is set to cross 450 MMT in the year 2030. Approximately 6300 MMT of plastic wastes has accumulated in the environment during the past 65 years. About 5700 MMT of which were produced as single-use plastics, and most of which may not be recycled. Current understanding is that plastic, in any form, found in the environment is purely anthropogenic. Not surprisingly, as a result, each member of the human species is exposed to 2.93 × 1010 microplastic particles/year.KeywordsPlasticHabitatPolymerMonomerBiomassFossil fuelPolyvinylchloridePolystyrenePolyethyleneNylonInsulationThermal resistanceElectrical insulationCorrosion resistivity
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Plastics in the marine environment have become a major concern because of their persistence at sea, and adverse consequences to marine life and potentially human health. Implementing mitigation strategies requires an understanding and quantification of marine plastic sources, taking spatial and temporal variability into account. Here we present a global model of plastic inputs from rivers into oceans based on waste management, population density and hydrological information. Our model is calibrated against measurements available in the literature. We estimate that between 1.15 and 2.41 million tonnes of plastic waste currently enters the ocean every year from rivers, with over 74% of emissions occurring between May and October. The top 20 polluting rivers, mostly located in Asia, account for 67% of the global total. The findings of this study provide baseline data for ocean plastic mass balance exercises, and assist in prioritizing future plastic debris monitoring and mitigation strategies.
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The ecological dynamics of microplastic (<5 mm) are well documented in marine ecosystems, but the sources, abundance, and ecological role of microplastic in rivers are unknown and likely to be substantial. Microplastic fibers (e.g., synthetic fabrics) and pellets (e.g., abrasives in personal care products) are abundant in wastewater treatment plant (WWTP) effluent, and can serve as a point source of microplastic in rivers. The buoyancy, hydrophobic surface, and long transport distance of microplastic make it a novel substrate for the selection and dispersal of unique microbial assemblages. We measured microplastic concentration and bacterial assemblage composition on microplastic and natural surfaces upstream and downstream of WWTP effluent sites at nine rivers in Illinois, United States. Microplastic concentration was higher downstream of WWTP effluent outfall sites in all but two rivers. Pellets, fibers, and fragments were the dominant microplastic types, and polymers were identified as polypropylene, polyethylene, and polystyrene. Mean microplastic flux was 1,338,757 pieces per day, although the flux was highly variable among nine sites (min = 15,520 per day, max = 4,721,709 per day). High-throughput sequencing of 16S rRNA genes showed bacterial assemblage composition was significantly different among microplastic, seston, and water column substrates. Microplastic bacterial assemblages had lower taxon richness, diversity, and evenness than those on other substrates, and microplastic selected for taxa that may degrade plastic polymers (e.g., Pseudomonas) and those representing common human intestinal pathogens (e.g., Arcobacter). Effluent from WWTPs in rivers is an important component of the global plastic “life cycle,” and microplastic serves as a novel substrate that selects and transports distinct bacterial assemblages in urban rivers. Rates of microplastic deposition, consumption by stream biota, and the metabolic capacity of microplastic biofilms in rivers are unknown and merit further research.
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Plastic debris is a growing contaminant of concern in freshwater environments, yet sources, transport, and fate remain unclear. This study characterized the quantity and morphology of floating micro- and macroplastics in 29 Great Lakes tributaries in six states under different land covers, wastewater effluent contributions, population densities, and hydrologic conditions. Tributaries were sampled three or four times each using a 333 μm mesh neuston net. Plastic particles were sorted by size, counted, and categorized as fibers/lines, pellets/beads, foams, films, and fragments. Plastics were found in all 107 samples, with a maximum concentration of 32 particles/m(3) and a median of 1.9 particles/m(3). Ninety-eight percent of sampled plastic particles were less than 4.75 mm in diameter and therefore considered microplastics. Fragments, films, foams, and pellets/beads were positively correlated with urban-related watershed attributes and were found at greater concentrations during runoff-event conditions. Fibers, the most frequently detected particle type, were not associated with urban-related watershed attributes, wastewater effluent contribution, or hydrologic condition. Results from this study add to the body of information currently available on microplastics in different environmental compartments, including unique contributions to quantify their occurrence and variability in rivers with a wide variety of different land-use characteristics while highlighting differences between surface samples from rivers compared with lakes.
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Microplastics result from fragmentation of plastic debris or are released to the environment as preproduction pellets or components of consumer and industrial products. In the oceans, they contribute to the 'great garbage patches'. They are ingested by many organisms, from protozoa to baleen whales, and pose a threat to the aquatic fauna. Although as much as 80% of marine debris originates from land, little attention was given to the role of rivers as debris pathways to the sea. Worldwide, not a single great river has yet been studied for the surface microplastics load over its length. We report the abundance and composition of microplastics at the surface of the Rhine, one of the largest European rivers. Measurements were made at 11 locations over a stretch of 820 km. Microplastics were found in all samples, with 892,777 particles km(-2) on average. In the Rhine-Ruhr metropolitan area, a peak concentration of 3.9 million particles km(-2) was measured. Microplastics concentrations were diverse along and across the river, reflecting various sources and sinks such as waste water treatment plants, tributaries and weirs. Measures should be implemented to avoid and reduce the pollution with anthropogenic litter in aquatic ecosystems.
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Microplastic debris floating at the ocean surface can harm marine life. Understanding the severity of this harm requires knowledge of plastic abundance and distributions. Dozens of expeditions measuring microplastics have been carried out since the 1970s, but they have primarily focused on the North Atlantic and North Pacific accumulation zones, with much sparser coverage elsewhere. Here, we use the largest dataset of microplastic measurements assembled to date to assess the confidence we can have in global estimates of microplastic abundance and mass. We use a rigorous statistical framework to standardize a global dataset of plastic marine debris measured using surface-trawling plankton nets and coupled this with three different ocean circulation models to spatially interpolate the observations. Our estimates show that the accumulated number of microplastic particles in 2014 ranges from 15 to 51 trillion particles, weighing between 93 and 236 thousand metric tons, which is only approximately 1% of global plastic waste estimated to enter the ocean in the year 2010. These estimates are larger than previous global estimates, but vary widely because the scarcity of data in most of the world ocean, differences in model formulations, and fundamental knowledge gaps in the sources, transformations and fates of microplastics in the ocean.
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The quantity and composition of litter at riversides and in the surface waters, as well as the occurrence of illegal dumping sites, were studied along four rivers in Chile. Data generated by volunteers were compared to the results from a professional survey, using an identical protocol. Litter was found in considerable quantities at the riversides and in the surface waters at all the sites investigated. A generalized linear mixed model analysis showed that the recorded litter densities did not differ between volunteers and professionals, even after controlling for river, site, or distance between sampling locations, demonstrating that the volunteers successfully applied the sampling protocol. Differences occurred with respect to litter composition, which is most likely due to difficulties in the classification of litter items and particles and to the underestimation of litter present in surface water samples. Even though this study was only conducted at a small number of rivers and sites, a comparatively consistent pattern of direct and intentional litter deposition at riversides was recorded, highlighting that river basins require more protection. The results also show that the citizen science approach can be a suitable means for more extensive litter surveys at riversides and in other natural environments.
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Plastic pollution is ubiquitous throughout the marine environment, yet estimates of the global abundance and weight of floating plastics have lacked data, particularly from the Southern Hemisphere and remote regions. Here we report an estimate of the total number of plastic particles and their weight floating in the world’s oceans from 24 expeditions (2007–2013) across all five sub-tropical gyres, costal Australia, Bay of Bengal and the Mediterranean Sea conducting surface net tows (N5680) and visual survey transects of large plastic debris (N5891). Using an oceanographic model of floating debris dispersal calibrated by our data, and correcting for wind-driven vertical mixing, we estimate a minimum of 5.25 trillion particles weighing 268,940 tons. When comparing between four size classes, two microplastic ,4.75 mm and meso- and macroplastic .4.75 mm, a tremendous loss of microplastics is observed from the sea surface compared to expected rates of fragmentation, suggesting there are mechanisms at play that remove ,4.75 mm plastic particles from the ocean surface.
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Background: While the use of plastic materials has generated huge societal benefits, the ‘plastic age’ comes with downsides: One issue of emerging concern is the accumulation of plastics in the aquatic environment. Here, so-called microplastics (MP), fragments smaller than 5 mm, are of special concern because they can be ingested throughout the food web more readily than larger particles. Focusing on freshwater MP, we briefly review the state of the science to identify gaps of knowledge and deduce research needs. State of the science: Environmental scientists started investigating marine (micro)plastics in the early 2000s. Today, a wealth of studies demonstrates that MP have ubiquitously permeated the marine ecosystem, including the polar regions and the deep sea. MP ingestion has been documented for an increasing number of marine species. However, to date, only few studies investigate their biological effects. The majority of marine plastics are considered to originate from land-based sources, including surface waters. Although they may be important transport pathways of MP, data from freshwater ecosystems is scarce. So far, only few studies provide evidence for the presence of MP in rivers and lakes. Data on MP uptake by freshwater invertebrates and fish is very limited. Knowledge gaps: While the research on marine MP is more advanced, there are immense gaps of knowledge regarding freshwater MP. Data on their abundance is fragmentary for large and absent for small surface waters.Likewise, relevant sources and the environmental fate remain to be investigated. Data on the biological effects of MP in freshwater species is completely lacking. The accumulation of other freshwater contaminants on MP is of special interest because ingestion might increase the chemical exposure. Again, data is unavailable on this important issue. Conclusions: MP represent freshwater contaminants of emerging concern. However, to assess the environmental risk associated with MP, comprehensive data on their abundance, fate, sources, and biological effects in freshwater ecosystems are needed. Establishing such data critically depends on a collaborative effort by environmental scientists from diverse disciplines (chemistry, hydrology, ecotoxicology, etc.) and, unsurprisingly, on the allocation of sufficient public funding.
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There is a rising concern regarding the accumulation of floating plastic debris in the open ocean. However, the magnitude and the fate of this pollution are still open questions. Using data from the Malaspina 2010 circumnavigation, regional surveys, and previously published reports, we show a worldwide distribution of plastic on the surface of the open ocean, mostly accumulating in the convergence zones of each of the five subtropical gyres with comparable density. However, the global load of plastic on the open ocean surface was estimated to be on the order of tens of thousands of tons, far less than expected. Our observations of the size distribution of floating plastic debris point at important size-selective sinks removing millimeter-sized fragments of floating plastic on a large scale. This sink may involve a combination of fast nano-fragmentation of the microplastic into particles of microns or smaller, their transference to the ocean interior by food webs and ballasting processes, and processes yet to be discovered. Resolving the fate of the missing plastic debris is of fundamental importance to determine the nature and significance of the impacts of plastic pollution in the ocean.
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Accumulation of anthropogenic litter (i.e. garbage; AL) and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1) quantify AL density in urban freshwaters, 2) compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3) characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP) and community respiration (CR), and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond), but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves) had lower GPP than hard substrates (glass, plastic, aluminum and tiles). In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across multiple ecosystem types, and will benefit management and reduction of global AL accumulations.
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Previous studies on plastic pollution of aquatic ecosystems focused on the world's oceans. Large rivers as major pathways for land-based plastic litter, has received less attention so far. Here we report on plastic quantities in the Austrian Danube. A two year survey (2010, 2012) using stationary driftnets detected mean plastic abundance (n = 17,349; mean ± S.D: 316.8 ± 4664.6 items per 1000 m(-3)) and mass (4.8 ± 24.2 g per 1000 m(-3)) in the river to be higher than those of drifting larval fish (n = 24,049; 275.3 ± 745.0 individuals. 1000 m(-3) and 3.2 ± 8.6 g 1000 m(-3)). Industrial raw material (pellets, flakes and spherules) accounted for substantial parts (79.4%) of the plastic debris. The plastic input via the Danube into the Black Sea was estimated to 4.2 t per day.
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Small plastic detritus, termed 'microplastics', are a widespread and ubiquitous contaminant of marine ecosystems across the globe. Ingestion of microplastics by marine biota, including mussels, worms, fish and seabirds, has been widely reported, but despite their vital ecological role in marine food-webs, the impact of microplastics on zooplankton remains under-researched. Here, we show that microplastics are ingested by, and may impact upon, zooplankton. We used bio-imaging techniques to document ingestion, egestion and adherence of microplastics in a range of zooplankton common to the northeast Atlantic, and employed feeding rate studies to determine the impact of plastic detritus on algal ingestion rates in copepods. Using fluorescence and coherent anti-Stokes Raman scattering (CARS) microscopy we identified that thirteen zooplankton taxa had the capacity to ingest 1.7 - 30.6 µm polystyrene beads, with uptake varying by taxa, life-stage and bead-size. Post-ingestion, copepods egested faecal pellets laden with microplastics. We further observed microplastics adhered to the external carapace and appendages of exposed zooplankton. Exposure of the copepod Centropages typicus to natural assemblages of algae with and without microplastics showed that 7.3 µm microplastics (>4000 ml-1) significantly decreased algal feeding. Our findings imply that marine microplastic debris can negatively impact upon zooplankton function and health.
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Much of the debris in the near-surface ocean collects in so-called garbage patches where, due to convergence of the surface flow, the debris is trapped for decades to millennia. Until now, studies modelling the pathways of surface marine debris have not included release from coasts or factored in the possibilities that release concentrations vary with region or that pathways may include seasonal cycles. Here, we use observational data from the Global Drifter Program in a particle-trajectory tracer approach that includes the seasonal cycle to study the fate of marine debris in the open ocean from coastal regions around the world on interannual to centennial timescales. We find that six major garbage patches emerge, one in each of the five subtropical basins and one previously unreported patch in the Barents Sea. The evolution of each of the six patches is markedly different. With the exception of the North Pacific, all patches are much more dispersive than expected from linear ocean circulation theory, suggesting that on centennial timescales the different basins are much better connected than previously thought and that inter-ocean exchanges play a large role in the spreading of marine debris. This study suggests that, over multi-millennial timescales, a significant amount of the debris released outside of the North Atlantic will eventually end up in the North Pacific patch, the main attractor of global marine debris.
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Plastic marine pollution is a major environmental concern, yet a quantitative description of the scope of this problem in the open ocean is lacking. Here, we present a time series of plastic content at the surface of the western North Atlantic Ocean and Caribbean Sea from 1986 to 2008. More than 60% of 6136 surface plankton net tows collected buoyant plastic pieces, typically millimeters in size. The highest concentration of plastic debris was observed in subtropical latitudes and associated with the observed large-scale convergence in surface currents predicted by Ekman dynamics. Despite a rapid increase in plastic production and disposal during this time period, no trend in plastic concentration was observed in the region of highest accumulation.
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For a large set of major world rivers we established the empirical relations existing betwin the observed organic carbon fluxes and the climatic, biologic, and geomorphologic paterns characterizing the river basins.These characteristics where extracting from various ecological databases. The corresponding carbon fluxes were taken from the literature. Dissolved organic carbon fluxes are mainly related to drainage intensity, basin slope, and the amount of carbon stored in soils. Particulate organic carbon fluxes are calculated as a function of sediment fluxes, which depend principally upon drainage intensy, rainfall intensity, and basin slope. Although the drainage intensity is mainly related to the amount of precipitation and to mean temperature in the basin, slope is also retained as one of controlling factors. Our empirical models result in a total organic carbon flux to the oceans of about 0.38 Gt per year globally. About 0.21 Gt carbon (Gt C)enter the oceans in dissolved from and about 0.17 Gt C in particulate form. we further regionalize fluxes with respect to major climates, different continents, and different ocean basins. About 45% of the organic carbon is discharged from tropical wet regions. the major part of the dissolved organic carbon is discharged into the Atlantic Ocean, while the bulk of the particulate organic carbon is discharged into the Indian and Pacific Oceans.
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Millions of metric tons of plastic are produced annually. Countless large items of plastic debris are accumulating in marine habitats worldwide and may persist for centuries ([ 1 ][1]–[ 4 ][2]). Here we show that microscopic plastic fragments and fibers ([Fig. 1A][3]) are also widespread in the
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With humans having an increasing impact on the planet, the interactions between the nitrogen cycle, the carbon cycle and climate are expected to become an increasingly important determinant of the Earth system.
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Microplastics have been considered as an emerging pollutant in the aquatic environment. However, research about microplastic pollution in inland freshwaters of China is insufficient. The present study investigated the levels of microplastics in surface water of 20 urban lakes and urban reaches of the Hanjiang River and Yangtze River of Wuhan, the largest city in central China. Microplastic concentrations ranged from 1660.0±639.1 to 8925±1591n/m³ for the studied waters, with the highest concentration found in Bei Lake. Microplastic abundance in lakes varied markedly in space, and negatively correlated with the distance from the city center (p <0.001), which confirmed the important role of anthropogenic factors in microplastic distribution. Urban reaches of the Hanjiang River and Yangtze River were found to have relatively lower levels of microplastics than most of the studied lakes. The major type of microplastics among the studied waters was colored plastic, with fiber being the most frequent shape. More than 80% of microplastics in number had a size of <2mm. Polyethylene terephthalate and polypropylene were the dominant polymer-types of microplastics analyzed. This study provided important reference for better understanding microplastic levels in inland freshwaters.
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Riverine transport to the marine environment is an important pathway for microplastic. However, information on fate and transport of nano- and microplastic in freshwater systems is lacking. Here we present scenario studies on the fate and transport of nano-to millimetre sized spherical particles like microbeads (100 nm–10 mm) with a state of the art spatiotemporally resolved hydrological model. The model accounts for advective transport, homo- and heteroaggregation, sedimentation-resuspension, polymer degradation, presence of biofilm and burial. Literature data were used to parameterize the model and additionally the attachment efficiency for heteroaggregation was determined experimentally. The attachment efficiency ranged from 0.004 to 0.2 for 70 nm and 1050 nm polystyrene particles aggregating with kaolin or bentonite clays in natural freshwater. Modeled effects of polymer density (1–1.5 kg/L) and biofilm formation were not large, due to the fact that variations in polymer density are largely overwhelmed by excess mass of suspended solids that form heteroaggregates with microplastic. Particle size had a dramatic effect on the modeled fate and retention of microplastic and on the positioning of the accumulation hot spots in the sediment along the river. Remarkably, retention was lowest (18–25%) for intermediate sized particles of about 5 μm, which implies that the smaller submicron particles as well as larger micro- and millimetre sized plastic are preferentially retained. Our results suggest that river hydrodynamics affect microplastic size distributions with profound implications for emissions to marine systems.
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The global estimation of microplastic afloat in the ocean is only approximately 1% of global plastic inputs. This reflects fundamental knowledge gaps in the transformation, fragmentation and fates of microplastics in the ocean. In order to better understand microplastic fragmentation we proceeded to a thorough physicochemical characterization of samples collected from the North Artlantic sub-tropical gyre during the sea campaign Expedition 7th Continent in May 2014. The results were confronted with a mathematical approach. The introduction of mass distribution in opposition to the size distribution commonly proposed in this area clarify the fragmentation pattern. The mathematical analysis of the mass distribution points out a lack of mass for debris lighter than 1 mg, which corresponds to a size of 2 mm. Characterization by means of microscopy, microtomography and infrared microscopy gives a better understanding of the behavior of microplastic at sea. Flat pieces of debris (5-2 mm), referred to as parallelepipeds, float with one face preferentially exposed to the sun. This face is more photodegraded and biofilm also develops preferentially on it. Smaller debris, with a cubic shape (below 2 mm), seems to roll at sea. All faces are evenly photodegraded and they are less colonized. The breakpoint in the mathematical model and the experimental observation around 2 to 1 mm leads to the conclusion that there is a discontinuity in the rate of fragmentation: we hypothesized that the smaller microplastics, the cubic ones mostly, are fragmented much faster than the parallelepipeds.
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Marine microplastic (,5 mm) water pollution has met growing public and scientific interest in the last few years. The situation in freshwater environments remains largely unknown, although it appears that they play an important role as part of the origin of marine pollution. Apart from the physical impacts on biota, chemical effects are to be expected as well, especially with smaller particles. This study aims at assessing plastic abundance in Lakes Geneva, Constance, Neuchaˆtel, Maggiore, Zurich and Brienz, and identifying the nature of the particles, potential ingestion by birds and fishes, and the associated pollutants. Lake surface transects and a few rivers were sampled using a floating manta net, and beach sediments were analysed. Plastics were sorted by type (fragments, pellets, cosmetic beads, lines, fibres, films, foams) and composition (polypropylene, polyethylene, polystyrene, etc.); fish and water birds were dissected to assess their potential exposure, and analyses were conducted on the hydrophobic micropollutants adsorbed to the microplastics as well as some potentially toxic additives they contained. Evidence of this pollution is shown for all lakes, microplastics of all types and diverse composition having been found in all samples. Birds and fish are prone to microplastic ingestion, and all the tested chemicals (both adsorbed micropollutants and contained additives) were found above the detection limit, and often the quantification limit. The sources and their respective contribution need to be confirmed and quantified, and the ecotoxicological effects need further investigation. Other questions remain open, including the transport and fate of plastic particles in the environment.
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Anthropogenic debris contaminates marine habitats globally, leading to several perceived ecological impacts. Here, we critically and systematically review the literature regarding impacts of debris from several scientific fields to understand the weight of evidence regarding the ecological impacts of marine debris. We quantified perceived and demonstrated impacts across several levels of biological organization that make up the ecosystem and found 366 perceived threats of debris across all levels. Two hundred and ninety-six of these perceived threats were tested, 83% of which were demonstrated. The majority (82%) of demonstrated impacts were due to plastic, relative to other materials (e.g., metals, glass) and largely (89%) at suborganismal levels (e.g., molecular, cellular, tissue). The remaining impacts, demonstrated at higher levels of organization (i.e., death to individual organisms, changes in assemblages), were largely due to plastic marine debris (>1 mm; e.g., rope, straws, and fragments). Thus, we show evidence of ecological impacts from marine debris, but conclude that the quantity and quality of research requires improvement to allow the risk of ecological impacts of marine debris to be determined with precision. Still, our systematic review suggests that sufficient evidence exists for decision makers to begin to mitigate problematic plastic debris now, to avoid risk of irreversible harm.
Article
Environmental context Plastics production has increased considerably in recent years, leading to pollution by plastics, including microplastics (comprising particles smaller than 5mm). This work addresses the issue of microplastics from urban sources and in receiving waters in Greater Paris. Microplastics were found in all urban compartments investigated, namely atmospheric fallout, waste- and treated water, and surface water. Abstract This study investigates the microplastic contamination of both urban compartments (wastewater and total atmospheric fallout) and surface water in a continental environment. These first investigations on an urban environment confirm the presence of microplastics in sewage, fresh water and total atmospheric fallout and provide knowledge on the type and size distribution of microplastics in the 100-5000-μm range. For the first time, the presence of microplastics, mostly fibres, is highlighted in total atmospheric fallout (29-280particlesm-2day-1). High levels of fibres were found in wastewater (260-320×103particlesm-3). In treated effluent, the contamination significantly decreased to 14-50×103particlesm-3. In the River Seine, two sampling devices were used to collect both large and small microplastic particles: (i) a plankton net (80-μm mesh), and (ii) a manta trawl (330-μm mesh). Sampling with the plankton net showed a predominance of fibres, with concentrations ranging from 3 to 108particlesm-3. A greater diversity of both microplastic shapes and types was found during manta trawl sampling but at much lower concentrations (0.28-0.47particlesm-3). This combined approach could be relevant and implemented in future studies to provide an accurate overview of microplastic distribution in freshwater.
Article
Plastic debris is one of the most significant organic pollutants in the aquatic environment. Due to properties such as buoyancy and extreme durability, synthetic polymers are present in rivers, lakes and oceans and accumulate in sediments all over the world. However, freshwater sediments have attracted less attention than the investigation of sediments in marine ecosystems. For this reason, river shore sediments of the rivers Rhine and Main in the Rhine-Main area in Germany were analyzed. The sample locations comprised shore sediment of a large European river (Rhine) and a river characterized by industrial influence (Main) in areas with varying population sizes as well as sites in proximity to nature reserves. All sediments analyzed contained microplastic particles (<5mm) with mass fractions of up to 1 g kg-1 or 4000 particles kg-1 respectively. Analysis of the plastics by infrared spectroscopy showed a high abundance of polyethylene, polypropylene and polystyrene, which covered over 75% of all polymer types identified in the sediment. Short distance transport of plastic particles from the tributary to the main stream could be confirmed by the identification of pellets, which were separated from shore sediment samples of both rivers. This systematic study shows the emerging pollution of inland river sediments with microplastics and, as a consequence thereof, underlines the importance of rivers as transport vectors of microplastics into the ocean.
Article
Plastic contamination is an increasing environmental problem in marine systems where it has spread globally to even the most remote habitats. Plastic pieces in smaller size scales, microplastics (particles <5mm), have reached high densities (e.g., 100 000 items per m3) in waters and sediments, and are interacting with organisms and the environment in a variety of ways. Early investigations of freshwater systems suggest microplastic presence and interactions are equally as far reaching as are being observed in marine systems. Microplastics are being detected in freshwaters of Europe, North America, and Asia, and the first organismal studies are finding that freshwater fauna across a range of feeding guilds ingest microplastics.
Article
Plastic debris in the marine environment is widely documented, but the quantity of plastic entering the ocean from waste generated on land is unknown. By linking worldwide data on solid waste, population density, and economic status, we estimated the mass of land-based plastic waste entering the ocean. We calculate that 275 million metric tons (MT) of plastic waste was generated in 192 coastal countries in 2010, with 4.8 to 12.7 million MT entering the ocean. Population size and the quality of waste management systems largely determine which countries contribute the greatest mass of uncaptured waste available to become plastic marine debris. Without waste management infrastructure improvements, the cumulative quantity of plastic waste available to enter the ocean from land is predicted to increase by an order of magnitude by 2025. Copyright © 2015, American Association for the Advancement of Science.
Article
Recent research has documented microplastic particles (< 5 mm in diameter) in ocean habitats worldwide and in the Laurentian Great Lakes. Microplastic interacts with biota in these habitats, including microorganisms, raising concerns about its ecological effects. Rivers may transport microplastic to marine habitats and the Great Lakes, but data on microplastic in rivers is limited. In a highly urbanized river in Chicago, Illinois, USA, we measured concentrations of microplastic that met or exceeded those measured in oceans and the Great Lakes, and we demonstrated that wastewater treatment plant effluent was a point source of microplastic. Results from high-throughput sequencing showed that bacterial assemblages colonizing microplastic within the river were less diverse and were significantly different in taxonomic composition compared to those from the water column and suspended organic matter. Several taxa that include plastic decomposing organisms and pathogens were more abundant on microplastic. These results demonstrate that microplastic in rivers are a distinct microbial habitat and may be a novel vector for the downstream transport of unique bacterial assemblages. In addition, this study suggests that urban rivers are an overlooked and potentially significant component of the global microplastic life cycle.
Book
Rivers provide the primary link between land and sea. Utilizing the world’s largest database, this book presents a detailed analysis and synthesis of the processes affecting fluvial discharge of water, sediment and dissolved solids. The ways in which climatic variation, episodic events, and anthropogenic activities — past, present and future — affect the quantity and quality of river discharge are discussed in the final two chapters. The book contains 26 tables and more than 165 figures — many in full color — including global and regional maps. The book’s extensive appendix presents the 1534-river database as a series of 44 tables and 132 maps that provide quantitative data regarding the discharge of water, sediment and dissolved solids. The complete database is also presented within a GIS-based package available online at www.cambridge.org/milliman. River Discharge to the Coastal Ocean provides an invaluable resource for researchers, professionals and graduate students in hydrology, oceanography, geology, geomorphology and environmental policy.
Article
Estimation of sediment and nutrient loads is of crucial interest for a good assessment of water pollution. This paper proposes an overview of existing estimation methods and a framework to select the most suited one given available streamflow and concentration data. Correlations between contaminant concentration and streamflow should first be checked to generate missing concentration values by regression. However, correlations are not always strong, in which case the ratio estimator method is more appropriate. Given a 6-year data set (1989–1995) from the Beaurivage River (Québec, Canada) with, at best, a weekly sampling, the ratio estimator method was selected to estimate annual and seasonal loads of sediments and nutrients (N and P). Results show relatively steady annual loads (on average 8.1 and 1.1 kg ha yr K1 for total dissolved N and total P, respectively) and a low erosion rate (0.23 t ha yr K1). The results also confirm that nutrient and sediment transport via runoff is essentially a springtime process in this region, and they indicate that dissolved P represents the bulk of the total P load, most likely due to artificial subsurface drainage systems in the watershed. These results are compared to the results obtained by using averaging methods and to several other sources of information from literature, confirming the order of magnitude but highlighting some remaining uncertainties. Finally, some research avenues are proposed to improve the proposed framework and to investigate other estimation methods adapted to data characteristics. q 2006 Elsevier B.V. All rights reserved.