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Microplastic contamination in the San Francisco Bay, California, USA
... Asimismo, los microplásticos pueden ser fácilmente ingeridos por la fauna acuática debido a su alta biodisponibilidad y su tamaño (Lusher, 2015). La ingestión de microplásticos puede provocar diversas anomalías morfológicas en los peces, estrés oxidativo y fisiológico, reducción de las actividades enzimáticas, falsa satisfacción del hambre, baja tasa de crecimiento, complicaciones reproductivas (Sutton et al., 2016), así como obstrucciones internas y daños en el tracto digestivo (Baalkhuyur et al., 2018). Además, se ha registrado que la presencia de microplásticos en el tracto gastrointestinal puede generar efectos negativos asociados con los aditivos incorporados durante su fabricación o los contaminantes ambientales absorbidos por los plásticos en el transcurso del tiempo (Rochman et al., 2013). ...
... Por otra parte, el 70 % de las especies con microplásticos en su contenido estomacal es importante para la subsistencia de la población y del sector comercial, por lo que esta contaminación puede comprometer la sostenibilidad de los recursos pesqueros en el futuro (Dantas et al., 2020) debido a los daños morfológicos, anatómicos, fisiológicos e intestinales que provoca en los peces (Sutton et al., 2016). Además, es un riesgo potencial para la salud humana debido a la biomagnificación de estos microplásticos al absorber contaminantes orgánicos persistentes y transferirlos a través de la cadena trófica . ...
La familia de peces Sciaenidae es importante para el comercio y la soberanía alimentaria de los habitantes de la bahía de Tumaco, en el Pacífico colombiano. Sin embargo, hay pocos estudios sobre sus hábitos tróficos en esta bahía. En ese contexto, en este estudio nos propusimos determinar la ecología trófica y la ingesta incidental de microplásticos en peces Sciaenidae, así como su relación con la dinámica ambiental en la bahía de Tumaco. Para ello se hicieron cuatros muestreos (2020-2021) con artes de pesca artesanales (anzuelo, changa, transmallo) y se capturaron 467 individuos para examinar el contenido estomacal de los peces. Los ítems alimentarios fueron pesados y clasificados. Se estimó para cada especie la preferencia de presa, la similitud y diferencias espaciotemporales en las dietas y la asociación entre la dieta y los factores ambientales. Se encontró que los crustáceos representaron un ítem alimentario de consumo constante (92 %) y de gran importancia (80 %) para la mayoría de las especies. Además, los mayores consumos de crustáceos se presentaron en la zona externa del estuario, asociada a una mayor salinidad, oxígeno disuelto y transparencia, lo que determina mayor abundancia y riqueza de este recurso. Por otro lado, se detectó la ingesta incidental de microplásticos en 30 ejemplares, pertenecientes a 10 especies (70 % de ellas de interés comercial). Se concluyó que en la bahía de Tumaco se aprovechan los crustáceos, un recurso alimenticio común y abundante, y se evidenció la presencia de microplásticos en los peces.
... Lower abundances of MPs have been reported in the Gulf of Gabes (Zayen et al., 2020) and the San Francisco Bay (Sutton et al., 2016) compared to the findings of this study. Similarly, the study conducted on water sediment and fish in the Eastern Mediterranean reported lower values than those observed in this study (Guven et al., 2017). ...
... Consistent with our study, Erkan et al. (2021) also identified blue as the second dominant color after white. On the other hand, some studies did not provide specific information about the colors of the detected MPs (Suaria et al., 2016;Sutton et al., 2016;Adamopoulou et al., 2021;Kashiwabara et al., 2021). Detecting MP colors can be important for understanding their potential threat to marine species. ...
Microplastics (MPs) and their impacts have been extensively studied in the Mediterranean region. However, more research has yet to be conducted on assessing the extent of microplastic (MP) pollution in the eastern Aegean Sea, specifically in Izmir Bay. This study aims to evaluate the current state of MP pollution in surface water and sediment samples collected from Izmir Bay. Ten sampling stations were specifically selected, including locations near stream discharge points, maritime transportation piers, and port areas. Surface water samples were collected using a manta trawl net, while sediment samples were obtained using a Van Veen grab. The mean MP abundances in surface water ranged from 1,083,882 to 8,091,684 items/km 2. Fragment type MPs were dominant. In terms of size category, it was found that MP s of 500µm size were dominant. The dominant color of MPs was white. ATR-FTIR analyses revealed that polyethylene and polypropylene were the dominant polymer types. MP concentrations in sediment ranged from 2,125 to 4,925 items/ m 2 , with fiber-type MPs being the most abundant. Black-colored MPs were found to dominate in sediment samples. Overall, the MP levels in Izmir Bay were higher than previous studies findings. Therefore, it is crucial to conduct long-term monitoring studies to obtain more consistent and reliable data on MP pollution levels in Izmir Bay.
... MPs in soils can also inhibit root function and RuBisCO activity in plants which is the main photosynthetic enzyme for carbon fixation in the Calvin cycle, inhibit arsenic, copper, and cadmium detoxification, respiration, photosynthesis, and growth Zong et al., 2021). Kumar et al., 2022aKumar et al., , 2022bSutton et al., 2016). Various studies have showed that mangrove plants are significant players in trapping plastic or MP particles, however, the relationship between vegetation and MP pollution is poorly investigated (Nor and Obbard, 2014;Sutton et al., 2016;Zhao et al., 2018;Duan et al., 2020). ...
... Kumar et al., 2022aKumar et al., , 2022bSutton et al., 2016). Various studies have showed that mangrove plants are significant players in trapping plastic or MP particles, however, the relationship between vegetation and MP pollution is poorly investigated (Nor and Obbard, 2014;Sutton et al., 2016;Zhao et al., 2018;Duan et al., 2020). Vegetation height and density are known to affect MP distribution in the sediments, as high and dense mangrove seems to have greater abundance of MPs and vice-versa . ...
Microplastics (MPs) are a new and lesser-known pollutant that has intrigued the interest of scientists all over the world in recent decades. MP (<5mm in size) can enter marine environments such as mangrove forests in a variety of ways, interfering with the health of the environment and organisms. Mangroves are now getting increasingly exposed to microplastic contamination due to their proximity to human activities and their position as critical transitional zones between land and sea. The present study reviews the status of MPs contamination specifically in mangrove ecosystems situated in Asia. Different sources and characteristics of MPs, subsequent deposition of MPs in mangrove water and sediments, bioaccumulation in different organisms are discussed in this context. MP concentrations in sediments and organisms were higher in mangrove forests exposed to fishing, coastal tourism, urban, and industrial wastewater than in pristine areas. The distribution of MPs varies from organism to organism in mangrove ecosystems, and is significantly influenced by their morphometric characteristics, feeding habits, dwelling environment etc. Mangrove plants can accumulate microplastics in their roots, stem and leaves through absorption, adsorption and entrapment helping in reducing abundance of microplastic in the surrounding environment. Several bacterial and fungal species are reported from these mangrove ecosystems, which are capable of degrading MPs. The bioremediation potential of mangrove plants offers an innovative and sustainable approach to mitigate microplastic pollution. Diverse mechanisms of MP biodegradation by mangrove dwelling organisms are discussed in this context. Biotechnological applications can be utilized to explore the genetic potential of the floral and faunal species found in the Asian mangroves. Detailed studies are required to monitor, control, and evaluate MP pollution in sediments and various organisms in mangrove ecosystems in Asia as well as in other parts of the world.
... Aquatic organisms such as bivalves, mussels, zooplankton, shrimps, fishes, other invertebrates and vertebrates consume and uptake MPs as foods [19][20][21][22]. As a result, physical damage and health hazards, such as obstructing intestinal systems or gastrointestinal cuts, decreasing growth rate, blocked enzyme production, reproductive problems, pathological and oxidative stress are being observed in the aquatic species [23,24]. ...
... To calculate the number of MP particles, 100 gm of soil sample was examined from each sampling site. From the result and from Fig. 4, it is observed that MPs are in higher numbers in S1, S2, S8, S9, S10, S11, and S12 sites which are industrial regions and have the highest number in S1 (24). A total of 129 particles are found in these industrial areas which cover 85% of the total detected MPs in the entire study area. ...
Despite the high potential for microplastics (MPs) pollution in Bangladesh, the presence of MPs in the industrial region has largely been unexplored in Bangladesh. So, this study was conducted to determine whether MP pollution is prevalent in the industrial soil of Bangladesh and the extent of its toxicity. To examine MPs, a total of 12 soil samples were collected from the industrial region of Narayanganj, and a stereoscopic microscope was used to visually identify the MPs. Prior to that the technique of density separation and sieving was applied to extract MPs from those 12 soil samples. Among the twelve investigated samples, a total of 151 MPs (Mean: 12.6 ± 7.9 particles kg−1) were identified, which were mostly white and ranged in size from 0.5 to 1 mm. Different types of MPs according to their shapes such as fibers (60.3%), fragments (19.2%), films (10.6%), and foam (9.9%) have been detected. 7 MPs (Mean: 0.58 ± 0.79) have been found in 3 urban farmland sites, 15 MPs (Mean: 1.87 ± 1.81) in two near metropolitan areas, and 129 MPs (Mean: 4.6 ± 4.39) in 7 industrial locations. Five polymers were identified by μ-FTIR, among which Polyamide predominated, followed by Polypropylene. According to risk assessments, the region falls under hazard categories II and III, suggesting a moderate to high risk. This paper gives thorough information on the toxicity of MP in an industrial location; therefore, it may be useful in the development of effective methods to address environmental issues.
... Aquatic species either intentionally or unintentionally consume MPs, which then enter the food chain (Boerger et al., 2010;Davison and Asch, 2011;Watts et al., 2014;Hantoro et al., 2019;Qiao et al., 2019). Adverse impacts e.g., reduced growth, obstruct feeding tubes and appendages, impaired fertility, and oxidative stress of ingesting MPs by aquatic animals have already been reported in several studies (Fossi et al., 2016;Lusher et al., 2013;Sutton et al., 2016). However, the manufacturing of plastics worldwide is being increased dramatically for our daily use, reaching 390.7 million tonnes of plastic in 2021 (Plastics Europe, 2021; Ritchie and Roser, 2018) because of its cheaper production costs and durability (Devriese et al., 2015). ...
... Biology of Aquatic organisms can be changed by MPs in their tissues by preventing acetylcholinesterase (AChE) action in the fish brain (Ding et al., 2018). They may inhibit growth, obstruct feeding tubes and appendages, impair fertility, and cause oxidative stress (Fossi et al., 2016;Lusher et al., 2013;Sutton et al., 2016). Moreover, MPs can build up in mammals' liver, kidneys, and intestines from consumption of fish and crustaceans that contain MPs, which disrupts the metabolic process of lipid and energy (Deng et al., 2017). ...
Microplastics (MPs) have gained a serious attention as an emerging contaminant throughout the world because of their persistence and possible risks to aquatic ecosystems and human well-being. However, knowledge on MPs contamination from sub-tropical coastal systems is limited, and no study has been conducted on the MPs contamination in sediment from one of the highest sediment-laden estuaries, Meghna River, in the world. This is the first study to examine the quantity, morpho-chemical characteristics and contamination risk level of MPs from this large scale river. MPs were extracted from the sediment samples of 10 stations along the banks of the estuary by density separation, and then characterized using a stereomicroscope and Fourier Transform Infrared (FTIR) spectroscopy. The incidence of MPs varied from 12.5 to 55 item/kg dry sediment with an average of 28.67 ± 10.80 item/kg. The majority (78.5%) of the MPs were under 0.5 mm in size, with fibers being the most (74.1%) prevalent MPs type. Polypropylene (PP) was found to be the predominant polymer (53.4%), followed by polyethylene (PE, 20%), polystyrene (PS, 13.3%), and polyvinyl chloride (PVC, 13.3%). The highest occurrence of PP indicted the MPs in the estuary might be originated from clothing and dying industries, fishing nets, food packages, and pulp industries. The sampling stations were contaminated with MPs as shown by the contamination factor (CF) values and pollutant load index (PLI), both of which were >1. This study exposed new insights on the status of MPs in the sediments of the Meghna River, laying the groundwork for future research. The findings will contribute to estimate the global share of MPs to the marine environment.
... Aquatic organisms such as bivalves, mussels, zooplankton, shrimps, fishes, other invertebrates and vertebrates consume and uptake MPs as foods [19][20][21][22]. As a result, physical damage and health hazards, such as obstructing intestinal systems or gastrointestinal cuts, decreasing growth rate, blocked enzyme production, reproductive problems, pathological and oxidative stress are being observed in the aquatic species [23,24]. ...
... To calculate the number of MP particles, 100 gm of soil sample was examined from each sampling site. From the result and from Fig. 4, it is observed that MPs are in higher numbers in S1, S2, S8, S9, S10, S11, and S12 sites which are industrial regions and have the highest number in S1 (24). A total of 129 particles are found in these industrial areas which cover 85% of the total detected MPs in the entire study area. ...
... For instance, peristaltic pumps can be used to draw water samples, which are then filtered to capture MPs. Stainless steel screens or trawls may also be employed to collect MPs in water [25,66]. Additionally, biological and environmental samples are utilized to investigate MPs. ...
... Currently, there is no standard methodology. However, some of the techniques are outlined in Table 2. Visual inspection [14,66], spectroscopy [67,68], pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) [25], and scanning electron microscopy (SEM) [15] are the most frequent techniques used to detect MPs. Although a fast, inexpensive, and straightforward method, visual inspection has certain limitations, such as the inability to accurately differentiate MPs in the sample [70,77]. ...
Microplastics (MPs) are receiving increasing attention because of their potential harm to the environment and human health. This research aims to summarize the abundance, toxicological effects, and analysis methods of MPs, as well as present their current status and trends in scientific research. Bibliometric analysis confirmed a substantial rise in annual research papers on MPs, predominantly over the previous nine years. The central research areas relating to MPs include distribution, sources, toxic effects, analytical approaches, and adsorption of MPs with other pollutants. Airborne MPs are a primary source of microplastic pollution in remote areas. Humans may inhale and ingest MPs, leading to the accumulation of these particles in their bodies. Additionally, microplastics can have biological toxicity that poses a potential threat to human health. Standard procedures for sampling and both qualitative and quantitative analysis of microplastics in various environmental media must be established urgently to enable effective comparison of experimental conclusions.
... The hydrosphere is the primary sink for microplastics, where human activities such as tourism and wastewater treatment result in depositing microplastics in aquatic habitats [48]. For instance, seven million microplastic items are released every day into the aquatic habitat via wastewater treatment plant effluents [48,49]. Depending on the physical properties (e.g., shape and size), density, and chemical composition, microplastics can either accumulate in the hydrosphere (i.e., their immediate source of disposal) or travel to other remote environment areas such as glacial zones through various transport mechanisms [50,51,52]. ...
... The hydrosphere is the primary sink for microplastics, where human activities such as tourism and wastewater treatment result in depositing microplastics in aquatic habitats [48]. For instance, seven million microplastic items are released every day into the aquatic habitat via wastewater treatment plant effluents [48,49]. Depending on the physical properties (e.g., shape and size), density, and chemical composition, microplastics can either accumulate in the hydrosphere (i.e., their immediate source of disposal) or travel to other remote environment areas such as glacial zones through various transport mechanisms [50][51][52]. ...
Plastic litter is on the rise where plastic waste ends up in undesignated areas such as the coastal shorelines, where the plastic is exposed to environmental conditions. As a result, the degradation and decomposition of plastics occur, leading to the formation of smaller fragments of plastics, termed microplastics. Microplastics have recently been considered as an emerging class of contaminants due to their ecotoxicological impact on the aquatic environment as well as soil matrix. Microplastics are of a size less than 5 mm and are produced from either a primary source (such as plastic pellets, and beads in makeup products) or a secondary source (such as the wear and tear of normal-use plastics and washing of clothes and textiles). Microplastic pollution is spread across the hydrosphere, pedosphere, and atmosphere, and these environmental zones are being studied for microplastic accumulation individually. However, there exists a source–sink dynamic between these environmental compartments. This study reviews the available literature on microplastic research and discusses the current state of research on the fate and transport of microplastic in the hydrosphere, pedosphere, and atmosphere, explores the ecotoxicological impact of microplastics on aquatic and soil communities, and provides prospective future research directions and plastic waste management strategies to control microplastic pollution. While the fate of microplastics in the hydrosphere is well-documented and researched, studies on understanding the transport mechanism of microplastics in the pedosphere and atmosphere remain poorly understood.
... Information on the spatial-temporal distribution and abundance of microplastics is indispensable for developing management policies. Microplastics have been detected in coastal-marine waters worldwide (Chae et al., 2015;Cohen et al., 2019;Eriksen et al., 2018;Gray et al., 2018;Nakano et al., 2021;Sagawa et al., 2018;Sutton et al., 2016). Several reports have already been published regarding the concentration and distribution of plastic debris along with microplastics in the beach sediments (de Carvalho & Neto, 2016;Hidalgo-Ruz & Thiel, 2013;Ivar do Sul et al., 2009;Naji et al., 2019;Wessel et al., 2016). ...
... Kyeonggi coastal region, Korea; Delaware Bay, USA; Hiroshima Bay, Japan; San Francisco Bay, USA; and Tokyo Bay, Japan was found to be higher than the present findings as documented by Chae et al. (2015), Cohen et al. (2019), Sagawa et al. (2018), Sutton et al. (2016), andNakano et al. (2021), respectively. The abundance of microplastics in the surface water of the northern Bay of Bengal, Bangladesh, was lower than that reported in other bays due to its geographical features (Nakano et al., 2021). ...
Marine plastic debris is extensively documented as a worldwide ecological issue. This study elucidated the quantity and distribution of plastic items in surface water at Moheshkhali Channel, sandy beaches (Laboni beach and Crab beach), and salt beds at Moheshkhali Island from the Cox’s Bazar coast of the northern Bay of Bengal, Bangladesh in Asia. The mean concentrations of microplastics (< 5 mm) in surface water, beach sediments, and crude salt were recorded to be 0.021–0.023 items/m², 41.00–140.60 items/m², and 490–630 items/kg, respectively. However, the mean concentrations of mesoplastics (5–25 mm) in surface water, beach sediments, and crude salt were recorded to be 0.004–0.006 items/m², 14.00–43.20 items/m², and 5–9 items/kg, respectively. The abundance of plastics in surface water was higher in early summer than in winter. In the case of beach sediments and crude salt, plastics abundance was higher in late monsoon and early summer, respectively. Furthermore, numerous microplastics have been found in the crude salt of Cox’s Bazar coast, suggesting the possibility of ingesting such particles through food. Besides, six different types of plastics (fragment, film, fiber, foam, pellet, and microbead) were recorded, and positive correlations were found between mesoplastic and microplastic debris size classes. Fourier Transform Infrared spectroscopy was used to identify the plastic polymer types (> 300 μm items). Polyethylene (28–31%), polypropylene (25–28%), polystyrene (13–18%), and polyethylene terephthalate (12–15%) were the most common polymers in Cox’s Bazar Coast of the northern Bay of Bengal that may arise from coastal tourism activities and riverine inputs. Detailed and long-term investigations are necessary to comprehend, monitor, and avoid further plastic contamination in this coastal region.
... Microplastics (MPs) refer to plastic particles that are smaller than 5000 μm (Andrady 2011;Bridson et al. 2020;Fallon and Freeman 2021). These plastic particles can originate directly from manufacturing processes, such as purpose-built micro pellets used in cosmetics (primary MPs), or indirectly from larger pieces of plastic waste that have broken down over time (secondary MPs) (Sutton et al. 2016;Auta et al. 2017;Kokalj et al. 2021;Kiran et al. 2022). ...
... MP particles pose a risk to marine taxa as their small size makes them easily ingestible (Andrady 2011;Gago et al. 2016;Auta et al. 2017;Markic et al. 2018;Gambarini et al. 2021;Kurniawan et al. 2021). MPs can also bioaccumulate within organisms posing a threat to animal health (Fossi et al. 2016;Sutton et al. 2016;Auta et al. 2017;Webb et al. 2020). Although MPs and nanoplastics (NPs, <1 μm) are unable to be digested or absorbed themselves (Andrady 2017; Andrady and Rajapakse 2019), they can transport heavy metals, persistent organic pollutants (POPs), chemical additives such as plasticisers, and residual monomers (often from polystyrene), which can leech into organisms and may be toxic (Andrady 2011(Andrady , 2017Brennecke et al. 2016;Andrady and Rajapakse 2019;Fallon and Freeman 2021;Richardson et al. 2021). ...
Microplastic (MP) particles (<5000 µm) pose a risk to many marine organisms. Globally, sponges are important suspension-feeding organisms that may be particularly vulnerable to MPs since many of these particles fall within their food size range. However, there has been little research on spatial variation in MP abundance in sponges. Here we examined MP abundance and spatial variation in sponges from Aotearoa New Zealand (NZ). We aimed to confirm the presence of potential microplastics (PMPs) in samples from 45 sponge samples across six species and three sites in the Wellington Harbour. Samples were digested with bleach, filtered, and analysed using fluorescent microscopy to quantify and measure PMPs. PMPs were present in every sponge sample with abundances between 207 ± 131 and 1893 ± 396 PMP particles g⁻¹ (dry sponge weight). There were significant differences in PMP abundance between sites and between some species, but most of the variation was explained by site (40–53% vs. 4–24% of the variance). Our results suggest that PMP abundance in sponges is mainly explained by spatial variation in microplastic abundance rather than species identity.
... In Spain, Simon-Sánchez et al. (2019) found less than 4 items m − 3 even in urbanized areas and <2 items m − 3 in low-impacted areas. In the USA, the eight San Francisco Bay wastewater treatment plants discharged an average of 86 items m − 3 , and nine municipal wastewater treatment facilities in the Midwest and Northeast were found to discharge 50 items m − 3 (Sutton et al., 2016). Zhao et al. (2019) reviewed several studies in China, with overall mean abundances of microplastics in Changjiang Estuary and East China Sea found to be 157.2 ...
... The surface water also contained 1-4% films and 1-2% pellets. Fibers tend to predominate in most estuaries (Han et al., 2020;He et al., 2021;Pazos et al., 2021;Sutton et al., 2016;Teng et al., 2020;Xiong et al., 2019;Zhao et al., 2019Zhao et al., , 2015, however, some authors reported a majority of fragments (Lam et al., 2020;Polanco et al., 2020;Suteja et al., 2021). ...
Brazil is the fourth largest producer of plastic waste in the world, but studies on pollution of rivers and estuaries by microplastics are still scarce. This study is located in the state of Bahia (Northeast region) in ten estuarine environments around Todos dos Santos Bay (TDB), the largest Brazilian bay, where more than 3 million Brazilians live. The aim of the study was the evaluation of the input of microplastics into the TSB by river. Microplastic abundance, size, morphology and water quality were determined during three sampling campaigns. All river samples were highly polluted with microplastics (mostly <150 μm), up to 33,000 items m-3, exceeding values observed in most estuaries worldwide. The poor quality of the river water reflect the deficient treatment of domestic wastewater in the state of Bahia (49% are not treated), and in this study is shown a correlation with the abundance of microplastics, indicating their possible main source. Artisanal fishing can also contribute locally to this pollution. Morover, the results highlight the importance of sampling small microplastics (<100 μm) to avoid important underestimation of this pollution. Based on these data, the three major rivers would discharge 3.88 trillion items into the Bay each year, equivalent to 4.75 × 105 m2 of plastic. Further research in surface water systems is essential, given that the average wastewater treatment rates in the country and in the Northeast and North regions are only 43%, 32%, and 12%, respectively.
... The presence of fragments implied that secondary MPs were also a major source of MPs in urban runoff at the sampled sites (Piñon-Colin et al., 2020). These results show trends similar to those observed in other studies from the USA (Sutton et al., 2016), Italy (Vianello et al., 2013), Germany (Klein and Fischer, 2019), Japan (Tanaka and Takada, 2016) and China (Mao et al., 2020). ...
Microplastics (MPs) released from plastic products in daily life are present in the air and could be transported to freshwater environments along with rain. Recently, low-impact development (LID) facilities, such as permeable pavements, have been used to treat non-point source pollutants, including rainfall runoff. While runoff is treated by LID facilities, the periodic monitoring of MPs in rainfall and the efficiency of removal of MPs through LID facilities have rarely been investigated. Therefore, this case study focused on monitoring MPs in rainwater runoff and permeate from a permeable pavement in Busan, South Korea, thus evaluating the removal efficiency of MPs by a LID system. The initial rainfall runoff and permeate through the LID system were sampled, and the amounts, types, sizes, and shapes of MPs in the samples were analyzed using micro-Fourier Transform Infrared (FTIR) spectroscopy. The results showed that the distribution of MPs in the initial rainfall was affected by population in tested area. Polyethylene was the most common type of MPs in all the samples. Polyamide was only found in the LID samples because of the pollution caused by water flows and pavement materials. Fragment type MPs was most commonly observed and consisted of relatively small-sized (under 100 μm) particles. LID facilities were able to capture approximately 98% of MPs in the rainfall through a filtration process in the permeable pavement.
... Most of these organisms end up with MPs by preying upon them by mistake, accidental ingestion while filtering prey, deposit-feeding, or trophic transfer (GESAMP, 2016). That results in risks such as reduction in growth rate, reproductive dysfunction, false satisfaction, prohibited enzyme production, pathological and oxidative stress in exposed organisms (Mallik et al., 2021;Sutton et al., 2016;Fossi et al., 2016). ...
The study focuses on the abundance and characteristics of ubiquitous microplastic (MP) pollutants in different natural molluscan settling sites along the southwest coast of India. It assesses its bioavailability within the tissue of selected locally abundant edible bivalves and gastropods viz., Villorita cyprinoides, Paphia malabarica, Crassostrea madrasensis, Perna perna, and Babylonia spirata. The mean MP abundance was found to be 140.83±32.62 items/L in water, 270.56±102.48 items/kg in sediment and 15.33 ± 15.56 MP/g of the soft tissue of molluscan samples. Transparent and blue-coloured fibres of size >500 µm, primarily comprising polyethylene, polypropylene, polystyrene, low-density polyethylene, polyamide, polyester, polyvinyl chloride and polyethylene terephthalate, were the most dominant forms of MPs. Interestingly, except for Babylonia spirata, a negative correlation has been observed between MP abundance and different morphometric characteristics in all the studied species. Hence, pre-emptive measures are needed to reduce the MP load by employing effective bioremediations to ensure food safety.
... Their measurements show that the microplastic concentration in the Chesapeake Bay varied from ~5500 particles/km 2 to ~300,000 particles/ km 2 , which demonstrated positive correlations with population density and proportion of urban/suburban development within watersheds. Sutton et al. (2016) present the information on abundance, distribution, and composition of microplastics at nine sites in San Francisco Bay, California, USA. They found that with an average microplastic abundance of ~700,000 particles/km 2 , the surface water appears to have higher microplastic levels than other urban water bodies sampled in North America. ...
Microplastics pose a significant and growing threat to marine ecosystems and human health. Rivers serve as critical pathways for the entry of inland-produced microplastics into marine environments. In this paper, we developed a numerical modeling scheme using OpenFOAM to investigate the fate and transport of microplastics in a river system. Our simulation results show that microplastics undergo significant aggregation and breakage as they are transported downstream by river flows. This significantly alters the particle size distribution of microplastics. The aggregation-breakage process is mainly controlled by river hydrodynamics and pollution scale. Our findings suggest that a significant extent of particle aggregation occurs at an early stage of the release of microplastics in the river, while the aggregation-breakage process becomes limited as the microplastic plume is gradually dispersed and diluted downstream. Eddy diffusivity drives the dispersion of the microplastic plume in the river, and its spatial patterns affect the aggregation-breakage process.
... These MPs, along with other emerging contaminants, are recognized for their wide distribution and increasing accumulation rates in the marine biosphere (Andrady, 2011;Martín et al., 2022;Yin et al., 2019). The entry of MPs into water bodies occurs through various sources such as domestic waste, industrial effluents, sewage treatment plants, stormwater, and river transport, facilitated by surface runoff, wind currents, and improper disposal practices (Meijer et al., 2021;Sutton et al., 2016). Consequently, rivers play a significant role as the primary pathways for MPs to reach the oceans, making them a global concern (Lebreton et al., 2017;Meijer et al., 2021). ...
... Foram verificados 4 tipos diferentes de MPs (esferas, feixes de fibra, fibras e fragmentos), conforme a Figura 3. As fibras (56,86%) foram o tipo mais numeroso nas amostras, seguidas pelos fragmentos (25%). Este resultado é semelhante aos padrões relatados em muitos outros lugares, como nos Rios Elba e Reno, no Continente Europeu (Wagner et al., 2014); na Baía de São Francisco, nos Estados Unidos (Sutton et al., 2016); no Estuário de Tamar, no Reino Unido (Sadri & Thompson, 2014); no Estuário do Rio da Prata, na Argentina (Pazos et al., 2021) e no Estuário Amazônico, no Brasil (Novaes, 2018). As fibras são semelhantes a fios ou filamentos, sendo flexíveis, delgadas, com superfície lisa ou rugosa e extremidades bem definidas ou serrilhadas (Rochman et al., 2019). ...
Os microplásticos podem ser gerados por diversas atividades humanas e são encontrados em diferentes reservatórios ambientais, como os sedimentos fluviais. Considerando a rica biodiversidade da Amazônia e a intensa interferência antrópica na região, torna-se fundamental avaliar o estado dos seus recursos hídricos. Desse modo, o presente estudo teve como objetivo analisar a abundância, morfologia e cor dos microplásticos nos sedimentos do Rio Xingu, no Pará. A coleta de dados e análises foram realizadas em fevereiro de 2023. Os microplásticos foram coletados nos sedimentos do rio e extraídos a partir de princípios de densidade e flotação. Assim, foi detectada uma abundância média de 204±60 partículas/kg, com prevalência das fibras (56,86%) e dos fragmentos (25%), seguidos pelos feixes de fibra (10,78%) e esferas (7,35%). A maioria dos microplásticos encontrados era transparente (57,84%). Nossos resultados revelaram que a abundância de microplásticos no Rio Xingu é maior do que em sistemas dulcícolas localizados zonas agrícolas e de conservação, sendo comparável com aqueles inseridos em áreas urbanas e industriais. Desse modo, destaca-se a necessidade de ações políticas, sociais e ambientais para remediar a presença de microplásticos em sistemas fluviais amazônicos.
... The authors suggested that different physical properties of MP species could be explained by varying near-bottom current velocities in coastal areas (Zobkov and Esiukova, 2017). The findings of this study align with similar observations in the literature from various other studies (Matsuguma et al., 2017;Sutton et al., 2016;Yu et al., 2018;Phillips and Bonner, 2015;Wessel et al., 2016). ...
Microplastics (MPs) have become prevalent in various environmental compartments, including air, water, and soil, attracting attention as significant pollutant parameters. This study investigated the prevalence of MP pollution in surface sediments along Istanbul's Marmara Sea, encompassing the megacity and the Bosphorus. A comprehensive sampling approach was employed, covering 43 stations across four seasons and depths ranging from 5 to 70 m. The objective was to assess the impact of terrestrial, social, and industrial activities on MPs. The average concentrations varied per season, with fall, winter, spring, and summer values recorded as 2000 ± 4100, 1600 ± 3900, 4300 ± 12,000, and 9500 ± 20,300 particles/kg-DW. The study identified river stations in the Golden Horn and sea discharge locations as hotspots for high concentrations. Notably, the dominant shape shifted from fibers in fall, winter, and spring to fragments during summer, coinciding with mucilage occurrences. The study identified 11 different polymers, with polyethylene (44 %) and polypropylene (31 %) being the most common.
... The recent studies on MPs in stormwater hypothesize that stormwater runoff acts as a vector to transport land-based MPs to receiving waters (Grbić et al., 2020;Schernewski et al., 2021). It is estimated that 62 % of MPs in the Baltic Sea originate from stormwater (Schernewski et al., 2021), and few studies (Bailey et al., 2021;Sutton et al., 2016) reported higher concentrations of MPs in stormwater runoff as compared to wastewater treatment plant (WWTP) effluent. Few studies observed a significant increase in MP abundance in rivers (Hitchcock, 2020), estuaries (Hitchcock and Mitrovic, 2019;Yonkos et al., 2014), seawater (Gündogdu et al., 2018), and groundwater (Severini et al., 2022) after storm events. ...
Urban areas play a significant role in generating microplastics (MPs) through increased vehicular and human activities, making urban runoff a key source of MP pollution in receiving waterways. The composition of MPs is anticipated to vary with land use; hence, identifying the hotspots of contamination within urban areas is imperative for the targeted interventions to reduce MPs at their sources. This study collected one-liter stormwater runoffs from three different land uses as sheet flow during two storm events to quantify the MPs and identify the polymers transported from land-based sources. The analytical method included a combination of Fourier transform infrared spectrometer, Raman microscope, and Nile red staining techniques. This study analyzed the broad spectrum of MPs, i.e., 1 μm-5 mm, and tire wear and bitumen particles, considered the two major research gaps in stormwater studies. The MP concentrations were 67.7 ± 11.3 pL-1in commercial, 23 ± 10.3 pL-1 in residential, and 168.7 ± 37.1 pL-1in highways. The trend of MP concentrations followed an order of highway > commercial > residential with an exclusive presence of polymethylmethacrylate and ethylene-vinyl acetate in highways; cellophane, methylcellulose, polystyrene, polyamide, and polytetrafluorethylene in commercial; and high-density polyethylene in residential areas. The dominant MP morphology consisted of fragments, accounting for 89 % of the identified MPs, followed by 10 % fibers and 1 % films. This study observed a prevalence of MPs sizes <125 μm constituting 49 % of the total composition. These findings underscore the vital role of land use patterns in shaping MP abundance and reinforce the urgency of implementing effective management strategies to mitigate MP pollution in stormwater runoff.
... Plastics that enter seas and oceans are converted to macroplastics, mesoplastics, and microplastics following chemical and biological reactions, including solar degradation, biodegradation, etc. (Jambeck et al., 2015). Due to the small size (1 µm to 5 mm) and global occurrence in coastal-marine waters (Alimba and Faggio, 2019;Amelia et al., 2021;Fatema et al., 2023;González-Ortegón et al., 2022;Napper et al., 2021;Sutton et al., 2016), microplastic (MP) are readily available to different aquatic biota in all water columns (Foekema et al., 2013;Mathalon and Hill, 2014). ...
Fish inhabiting various trophic levels are affected differently as the presence of microplastic (MP) in the water column and their ingestion by fish varies. Walking catfish (Clarias batrachus) inhabits the bottom of the water bodies. To understand the effects of MP, we exposed C. batrachus to two types of MP - polyethylene terephthalate (PET) and low-density polyethylene (LDPE) for 60 days. After exposure, hematological indices, mainly red blood cells and hemoglobin levels decreased, and white blood cells increased significantly compared to the control group (p<0.05). A significant increase in the levels of blood urea and glucose was observed, and serum glutamic pyruvate transaminase and serum glutamyl oxaloacetic transaminase activity remained elevated (p<0.05). Histopathological examination of the liver, kidney, intestine, and gills showed morphological alterations. Moreover, MP exposure caused growth retardation (p<0.05) in C. batrachus. Widespread pollution of water bodies by MP may impose serious ecological risks to bottom-feeding fish in Bangladesh.
... Plastics and MPs enter freshwater systems from various pathways, such as wind advection, stormwater runoff and illegal plastic waste dump, among others, and they can be transported across environmental compartments with different residence times at each one (Sutton et al., 2016;Wagner and Lambert, 2018). Rivers, typically transport MPs from land-based sources to estuaries and the open ocean (Luo et al., 2019). ...
This study identified and quantified microplastics in the Bay of Asunción, Paraguay, and its main tributaries. Surface water samples were sieved in duplicate at six locations using stainless-steel sieves (0.3-4.75 mm range), digested employing the Fenton's reaction (Fe-catalysed H2O2 digestion), and floated using NaCl and NaI. Particles were inspected using a microscope and characterized by IR spectrometry. Microplastics were found in all samples; more abundant (p < 0.05) in water from the bay (13.2 ± 13.4 items·m-3) than from the tributaries (1.0 ± 0.5 items·m-3). Most microplastics were common polymers and their abundance was in the order polypropylene > high-density polyethylene > low-density polyethylene, transparent and white. The results were similar to other regional studies and suggested that their main source was single-use packaging, disposed inadequately due to poor garbage collection.
... MPs are ingested by different aquatic organisms inadvertently or wrongly as food particles and pose a serious risk to their health. The effect of consumption of MPs may include reduced growth rates, decreased reproductive ability, ulcers, abrasions, and oxidative stress to the aquatic organisms(Fossi et al., 2016;Sutton et al., 2016), asphyxiation, and restricted movements (Alimba and Faggio, 2019). ...
... MPs are tiny plastic particles with size less than 5 mm in diameter [2,3]. MPs have been detected in almost all the ecosystems including marine [4], freshwater [5,6], lakes [7], atmosphere [8,9] and in soil [10,11]. They are formed from a wide range of sources such as polymer manufacturing, synthetic fibres from clothing and textile industry, processing industries, cosmetics, and personal care products and due to breakdown of larger plastic products [12]. ...
Microplastics (MPs) are tiny pieces of plastic smaller than 5mm that have raised concerns to aquatic organisms and human health due to their ubiquitous presence. Wastewater Treatment Plants (WWTPs) are a significant point source for aquatic MPs pollution, as millions of MPs with different characteristics reach WWTPs through the Sewage. Even though, WWTPs are not specifically designed to remove MPs, researchers report that more than 90% of MPs can be removed in WWTPs. However, given the huge volumes of effluent discharge into natural aquatic bodies, even small concentrations of MPs in the effluent would be significant. A typical WWTP consists of three key stages: primary, secondary and tertiary. Removal of MPs in these stages is reviewed. In addition, plastics can adsorb toxic chemical and biological pollutants on its surface and can lead to spread of toxic pollutants in the environment. Therefore, in this review we aim to provide comprehensive knowledge about the sources of MPs in wastewater, their fate and removal in WWTPs, their interactions with different chemical and biological pollutants, and their effects on environment. In addition, it also highlights the different methodologies used for sampling, sample preparation and physical and chemical identification of MPs found in the WWTPs.
... The majority of MPs are found in bivalves, zooplankton, mussels, fish, shrimp, oysters, copepods, lugworms, and whales (Lusher et al. 2017). Some of the consequences of ingestion of these microscopic plastics are pathological stress, false satiation, reproductive difficulties, restricted enzyme production, lowered growth rate, and oxidative stress in organisms (Sutton et al. 2016). ...
Plastic marine debris is a common source of pollution. Recent research has shown that plastic debris has a negative impact on marine organisms and the environment. For the first time, we investigated the presence of microplastics (MPs) in the Nigerian Lagos Lagoon ecosystem water, sediment, and the most important fish species (Hepsetus odoe, Chrysichthys nigrodigitatus, Oreochromis niloticus, and Lachnolaimus maximus). MPs were found in water, sediment, and three carnivorous fish species (H. odoe, C. nigrodigitatus, and L. maximus), except for herbivorous O. niloticus, raising concerns about the health of the Nigerian Lagos Lagoon ecosystem and the human food chain. Across the lagoon, fibres were more concentrated in the water, while fragments predominated in the sediment. Plastic debris from recreational, industrial, and domestic wastes contributed significantly to this contamination. Given the potential dangers of MPs to human health, it is critical to protect the ecosystem and its inhabitants in the Lagoon from plastic pollution. Our findings highlight the need for urgent measures to protect Nigeria's fragile coastal and marine ecosystems.
... Though only <5% of MPs entering the WWTPs are present in the effluent, it is a significant source of contamination considering the huge volumes of effluents that are released daily into water bodies [19,20,81]. For example, the primary source of MP contamination in the US is from WWTP effluents causing a release of over 4 million MPs per facility per day [15,60,[82][83][84][85][86][87][88][89]. On the other hand, the sludge that captures 90% of MPs present in the influent is another major source of MP contamination when used for agricultural purposes. ...
Since the 1950s, plastic production has skyrocketed. Various environmental and human activities are leading to the formation and accumulation of microplastics (MPs) in aquatic and terrestrial ecosystems, causing detrimental effects on water, soil, plants, and living creatures. Wastewater treatment plants (WWTPs) are one of the primary MP management centers meant to check their entry into the natural systems. However, there are considerable limitations in effectively capturing, detecting, and characterizing these MPs in the inlet and outlet of WWTPs leading to “unaccounted MPs” that are eventually discharged into our ecosystems. In order to assess the holistic picture of the MPs’ distribution in the ecosystems, prevent the release of these omitted MPs into the environment, and formulate regulatory policies, it is vital to develop protocols that can be standardized across the globe to accurately detect and account for MPs in different sample types. This review will cover the details of current WWTP adoption procedures for MP management. Specifically, the following aspects are discussed: (i) several processes involved in the workflow of estimating MPs in the outlet of WWTPs; (ii) key limitations or challenges in each process that would increase the uncertainty in accurately estimating MPs; (iii) favorable recommendations that would lead to the standardization of protocols in the workflow and facilitate more accurate analysis of MPs; (iv) research opportunities to tackle the problem of ‘missing MPs’; and (v) future research directions for the efficient management of MPs. Considering the burgeoning research interest in the area of MPs, this work would help early scientists in understanding the current status in the field of MP analysis in the outlet of WWTPs.
... Microplastics have been reported in mangrove sediments e.g., in a study by Nor and Obbard (2014). Mangrove biota such as planktonic organisms, crustaceans, larval stages of commercial species, filter feeders such as mussels and seabirds are amply exposed to buoyant microplastics (Boerger et al., 2010;Fendall and Sewell, 2009), and their ingestion have been reported to cause pathological stress, false satiation, reproductive complications, endocrine disruption, hormonal imbalance, blocked enzyme production, reduced growth rate, and oxidative stress (Auta et al., 2017;Sutton et al., 2016;Fossi et al., 2016). ...
Marine sediments have been demonstrated to be a long-term sinks for microplastics and their
contamination in mangrove sediment are of no exception with relatively scarce information available
globally. This work aimed to determine the prevalence of microplastics in two natural mangrove forests
of a small island developing state, Mauritius, with emphasis on the proximity of human settlement and
anthropogenic activities. Sediments were collected in triplicates monthly from October to December
2018 at Ferney (remote site) and Mahebourg (populated site) in three tidal zones: seaward (Z1), middle
(Z2) and landward zone (Z3). Microplastics retrieved were classified in terms of shape and size classes.
Results showed the presence of microplastics in all sediment samples with average abundance of
107.4 ± 76.42 particles kg−1 at Ferney and 140.2 ± 85.38 particles kg−1 at Mahebourg. Average
microplastics abundance was highest in the ZI and Z3 tidal zones and least in Z2 at Ferney and
Mahebourg respectively. Majority of microplastics recovered were in the size class 800–1000 μm and
1000–2000 μm, and in the fragment and film shape that may be derived from the fragmentation of
larger plastic debris. This study is an important baseline for mangrove protection as it provides a better
understanding of microplastics pollution status and information for future planning of management
strategies on a local and regional scale.
... Marine and freshwater microplastics (MPs) have been the focus of previous studies. MPs have been detected in rivers, estuaries, and inshore and pelagic waters [1][2][3][4], including polar seawaters [5,6], posing a non-negligible ecological threat to aquatic plants and animals [7][8][9]. The COVID-19 pandemic in recent years has increased the use of personal protective plastic products, resulting in the production of plastics, such as face masks that are carelessly discarded in the environment, which has contributed to MP pollution [10]. ...
Microplastics are ubiquitously in various environments from the equator to the poles. Coastal agglomerations act as both a source and sink connecting the global microplastic cycles of oceans and continents. While the problem of microplastics is particularly severe and complex in the coastal zones, where both inland and marine pollution are concentrated, the present study aimed to provide hot topics and trends of coastal urban microplastic studies and to review the researches on microplastic pollution in the atmosphere and water bodies in coastal agglomerations in terms of characteristics, behavior, and health threat of microplastics. The results of the bibliometric analysis showed an increase in the annual output of microplastic research. Research hot topics and clusters were analyzed using the VOSviewer. Characteristics of microplastics varied in abundance, size, and polymer type in different environments and countries. Furthermore, coastal cities are taken as a system to sort out the input, output, and internal transmission pathways of microplastics. The health threat of microplastics to urban residents was briefly reviewed and the exposure and health risks of microplastics to infants and young children were of particular concern. Detailed and comprehensive studies on intervention and reduction in the transmission of microplastics between the atmosphere and water bodies, whether microplastics are harmful to infants and young children, and measures to reduce the risk of microplastic exposure are needed.
... Due to their buoyancy and low degradation rates, plastics in the environment are able to travel large distances, far from their source (Lohmann, 2017), being recorded across wide-ranging marine environments. For instance, an average microplastic abundance of 700,000 item km − 2 was registered at San Francisco Bay, in the USA (Sutton et al., 2016). Other studies from the South Pacific subtropical gyre report densities around 43,157 item km − 2 (Eriksen et al., 2013) and later, Hendrickson et al. (2018) reported an occurrence of microplastics at around 37,000 item km − 2 . ...
We report the occurrence of plastics and associated persistent organic pollutants (POPs) in surface waters from Northern Chilean Patagonia. A total of 200 particles were found during the conducted survey. The highest number of particles found was 0.6 item m − 3. We found that 53 % of the collected particles corresponded to plastic, with an average of 0.19 ± 0.18 item m − 3. Microplastics (68 %) were the dominant size found in the area, followed by macroplastics (18 %) and mesoplastics (14 %). Most plastic particles were white (55 %) while others were <10 % each. Black and light blue represented 9 %; red, dark blue, and other colors 7 %; and green 6 %. Fragments were the most frequent shape of plastic debris (38 %), followed by Styrofoam (30 %) and fiber (27 %). Higher PBDE levels were found in the central zone, and those were higher than DDT, PeCB, HCB, and PCB levels. This study is the first report on POP occurrence in marine plastic debris from Chiloé Sea in the Northern Chilean Patagonia.
Urban wastewater treatment plants (WWTPs) are major contributors of microplastics (MPs) in the environment, despite achieving relatively high removal percentages. This study conducted a comprehensive assessment of the abundance and characteristics of MPs in wastewater and sludge at various treatment stages at Gebze WWTP located in the Marmara Sea, for the first time. The influent exhibited an average MPs concentration of 70.1 ± 28.6 MPs/L. After undergoing the fine screen and grit chamber units, the MPs concentration significantly reduced to 19.7 ± 3.6 MPs/L, indicating an impressive removal rate of 71.8%. Upon completion of the secondary treatment, the effluent contained 7.1 ± 1.7 MPs/L, resulting in an overall MP removal of 89.9–91.0%. The findings indicated that fibers constituted the predominant particle shape, followed by fragments. Fibers were effectively removed through primary treatment (71.8%), while fragments were efficiently removed during secondary treatment (81.1%). The analysis of sludge samples from the aeration basin and sludge thickening tank revealed higher concentrations, with 14.3 and 25 folds increase compared to the influent, respectively indicating the accumulation of MPs in sludge. Despite the treatment process, it is noteworthy that the effluent still exhibited a significant abundance of fibers. Micro-Raman analysis identified polyethylene and polypropylene as the main polymer types present. Although the WWTP demonstrated a high overall removal rate, an estimated 1022.4 × 106 ± 244.8 × 106 MPs/d were still being discharged with the effluent into the Marmara Sea. Recognizing the potential impact of MPs on marine organisms, measures, such as introduction of tertiary treatment processes, were taken to mitigate this issue.
Stormwater is considered a pathway of microplastics to surface water systems, but the magnitude of microplastic pollution in stormwater and the efficacy of existing stormwater treatment methods are unknown. One potential solution for minimizing microplastics in surface waters is leveraging green infrastructure, such as green roofs, bioswales, and bioretention cells, which can be optimized for the removal of conventional and emerging contaminants. The goals of this study were to (1) establish baseline types and quantities of anthropogenic microparticles, including microplastics, found in stormwater, and (2) evaluate bioretention as a possible solution for reducing microplastics in stormwater. To understand baseline conditions, samples were taken from five different catch basins in North Portland, Oregon, USA, during four storm events and analyzed to quantify and characterize microparticles between 106 µm and 5 mm. A baseline concentration of 4.5 ± 2.2 (range 1.1–9.7) particles/L was found, with no observed differences in concentrations between sampling locations or storm events. Most identified microparticles were fibers (66%), and approximately 47% of the particles were cotton, followed by polyester/blend (33%) and nylon (9%). Microparticle concentrations were correlated with the concentration of total suspended solids and the number of pieces of litter collected during a litter survey. To determine the efficiency of bioretention systems for microplastic removal, laboratory bioretention columns were constructed and filled with three different geomedia (a City of Portland standard mix, a proprietary mix, and layered sand and compost). A total of nine columns (three replicates of each geomedia) were tested with stormwater collected from a catch basin in Portland that was spiked with synthetic microplastics (106–5,000 µm). A removal efficiency of 99.8% was observed across all bioretention columns, regardless of the media type. Results indicate green stormwater infrastructure, such as bioretention, may be an effective tool for reducing observed microplastic transport from urban runoff to receiving water bodies.
To reduce microplastic (MP) discharge into the aquatic environment, it is necessary to properly identify its sources and amounts. Here, specific MP sources, i.e., personal care products (PCPs), fibers from clothes, and tire-wear particles (TWPs) were focused, and MP generations from these sources in the Tokyo Bay watershed, Japan, were estimated based on statistical data on production and reported emission factors of the MP sources and executing considering uncertainty on the data. Potential annual MP emission into Tokyo Bay was estimated to be 10.2 ± 1.6, 38 ± 22, and 1500-1800 tons for PCPs, fibers, and TWPs, respectively. Emissions into Tokyo Bay by assuming MP density and diameter was estimated. For fiber, the fraction to potential emission was estimated at 1.0-2.8 %. This study contributes to determining potential discharge pathways. This will assist in the application of appropriate measures to reduce MP discharge into water bodies.
Microplastics are emerging pollutants that are ubiquitous in a wide range of environments, yet the accumulation of microplastics in wastewater treatment plants is of particular importance because wastewater treatment plants pour their effluents in ecosystems. Here we review microplastics in wastewater treatment plants with emphasis on the sources of microplastics, analytical methods, and removal methods. Sources of primary microplastic in wastewater are from microbeads in personal care products, plastic pellets, and scrubbers used in industry. Secondary microplastics are derived from laundering, tire and road particles, and leachate from landfills. There are various methods for microplastic sampling and identification, yet these methods are not standardized yet. In a conventional wastewater treatment plant, the highest reduction of microplastics occurs during primary treatment during the skimming and settling stage. Microplastics are further removed during sedimentation in secondary treatment. Wastewater treatment plants equipped with membrane bioreactor systems in a tertiary treatment achieved the highest microplastic removal efficiency up to 99.9%. Despite high removal efficiency and low concentration of microplastic in the effluent, a wastewater treatment plant still releases a considerable number of microplastics daily due to the large volume of treated wastewater.KeywordsMicroplasticsWastewater treatment plantsSampling and identificationOccurrenceRemoval efficiency
Coastal wetlands are recognized as carbon sinks that play an important role in mitigating global climate change because of the strong carbon uptake by vegetation and high carbon sequestration in the soil. Over the last few decades, plastic waste pollution in coastal zones has become increasingly serious owing to high-intensity anthropogenic activities. However, the influence of plastic waste (including foam waste) accumulation in coastal wetlands on carbon flux remains unclear. In the Yangtze Estuary, we investigated the variabilities of vegetation growth, carbon dioxide (CO2) and methane (CH4) fluxes, and soil properties in a clean Phragmites australis marsh and mudflat and a plastic-polluted marsh during summer and autumn. The clean marsh showed a strong CO2 uptake capacity (a carbon sink), and the clean mudflat showed a weak CO2 sink during the measurement period. However, polluted marshes are a significant source of CO2 emissions. Regardless of the season, the gross primary production and vegetation biomass of the polluted marshes were on average 9.5 and 1.1 times lower than those in the clean marshes, respectively. Ecosystem respiration and CH4 emissions in polluted marshes were significantly higher than those in clean marshes and mudflats. Generally, the soil bulk density and salinity in polluted marshes were lower, whereas the median particle size was higher at the polluted sites than at the clean sites. Increased soil porosity and decreased salinity may favor CO2 and CH4 emissions through gas diffusion pathways and microbiological behavior. Moreover, the concentrations of heavy metals in the soil of plastic-polluted marshes were 1.24-1.49 times higher than those in the clean marshes, which probably limited vegetation growth and CO2 uptake. Our study highlights the adverse effects of plastic pollution on the carbon sink functions of coastal ecosystems, which should receive global attention in coastal environmental management.
The pollution of microplastics (MPs) is a worldwide major concern, as they have become a major part of our food chain. MPs enter our ecosystem via different pathways, including anthropogenic activities and improper disposal of plastics. The aim of this article is to review the current scientific literature related to MPs and how they affect different life forms on earth. Briefly, MPs induced negative effects on humans are primarily linked with the oxidative stress and disruption in immunity. MPs not only affect the soil chemical and physical properties such as reduction in soil health and productivity but also impose harmful effects on soil microorganisms. Moreover, MP-induced plant growth reduction results from three complementary mechanisms: (i) reduction in root and shoot growth, (ii) reduction in photosynthesis accompanied by higher reactive oxygen species (ROS) production, and (iii) reduction in nutrient uptake via altered root growth. Given the negative effects of MPs on different life forms, it is important to remove or remediate them. We have discussed different MP removal methods including coagulation, membrane filtration technology, biochar, and biological degradation of MPs in soil and wastewater effluents. The use of ozone as ultrafiltration technique has also been shown as the most promising technique for MP removal. Finally, some future research recommendations are also put forward at the end to further enhance our understanding of the MPs induced negative effects on different life forms.
Graphical abstract
The flowchart shows the interaction of MPs from water contaminated with MPs with different parts of the ecosystem and final interaction with human health
The ubiquitous presence of microplastics (MPs) in natural water bodies reflects the global issue regarding these micropollutants. The main problem of MPs lies on the difficulty of removing these particles from water during wastewater and drinking water treatments. The release of MPs to the environment in treated wastewater contributed to the dispersion of these micropollutants, which enhances the harmful effect of MPs on fauna and flora. In addition, their presence in tap water entails a potential risk to human health since MPs can be directly consumed. The first step is being able to quantify and characterise these microparticles accurately. In this work, a comprehensive analysis on the presence of MPs in wastewater, drinking water and tap water has been conducted with emphasis on sampling methods, pre-treatment, MP size and analytical methods. Based on literature data, a standard experimental procedure has been proposed with the objective of recommending a methodology that allows the homogenisation of MP analysis in water samples. Finally, reported MP concentrations for influents and effluents of drinking and wastewater treatment plants and tap water have been analysed, in terms of abundance, ranges and average values, and a tentative classification of different waters based on their MP concentrations is proposed.
Microplastics determined in surface water trawls from coastal waters around Plymouth, southwest England, ranged from 1.3 to 3.4 n m-3, with a decrease evident from the lower estuaries of the Tamar and Plym to areas in Plymouth Sound more remote from urbanisation. Microplastics were dominated by fibres of rayon and polypropylene and fragments of polyester and epoxy resins, with fragment concentration demonstrating a significant and positive linear relationship with concentration of floating and suspended matter retrieved by the trawls. Observations are attributed to the suspension of land-based (e.g., treated municipal waste) sources of textile fibres, and the flotation of land-based and in situ emissions of paints and resins from boating and shipping activities. The implied decoupling of microplastic transport based on shape and origin merits further investigation while the more general determination of floating and suspended matter concentration in microplastic studies is recommended.
Microplastics are regarded as emergent contaminants posing a serious threat to the marine ecosystem. It is time-consuming and labor-intensive to determine the number of microplastics in different seas using traditional sampling and detection methods. Machine learning can provide a promising tool for prediction, but there is a lack of research on this. To screen high-performance models for the prediction of microplastic abundance in the marine surface water and explore the influencing factors, three ensemble learning models, random forest (RF), gradient boosted decision tree (GBDT), and extreme gradient boosting (XGBoost), were developed and compared. A total of 1169 samples were collected, and multi-classification prediction models were constructed with 16 features of the data as inputs and six classes of microplastic abundance intervals as outputs. Our results show that the XGBoost model has the best performance of prediction, with a total accuracy rate of 0.719 and an ROC AUC (Receiver Operating Characteristic curve, Area Under Curve) value of 0.914. The distance between the sampling point and the coast (DIS), seawater phosphate (PHOS), and seawater temperature (TEMP) have negative effects on the abundance of microplastics in surface seawater, while the influence of wind stress (WS), human development index (HDI), and sampling latitude (LAT) have positive effects. This work not only predicts the abundance of microplastics in different seas but also offers a framework for the use of machine learning in the study of marine microplastics.
Increased industrial and agricultural activity has led to the contamination of the earth's soil and groundwater resources with hazardous chemicals. The presence of heavy metals, dyes, fluorides, dissolved solids, and many other pollutants used in industry and agriculture are responsible for hazardous levels of water pollution. The removal of these pollutants in water resources is challenging. Bioremediation is a new technique that employs living organisms, usually bacteria and fungi, to remove pollutants from soil and water, preferably in situ. This approach is more cost-effective than traditional techniques, such as incineration of soils and carbon filtration of water. It requires understanding how organisms consume and transform polluting chemicals, survive in polluted environments, and how they should be employed in the field. Bioremediation for Environmental Pollutants discusses the latest research in green chemistry and practices and principles involved in quality improvement of water by remediation. It covers different aspects of environmental problems and their remedies with up-to-date developments in the field of bioremediation of industrial/environmental pollutants. Volume 1 focuses on the bioremediation of heavy metals, pesticides, textile dyes removal, petroleum hydrocarbon, microplastics and plastics.
Urban drainage system is an important channel for terrigenous microplastics (<5 mm in size) to migrate to urban water bodies, especially the input load caused by overflow pollution in wet weather. Investigating how they transport and discharge is essential to better understand the occurrence and variability of microplastics in different water ecosystems. This study evaluated the abundance and distribution characteristics of microplastics in the drainage systems of typical coastal cities in China. The impacts of meteorological conditions and land use were explored. In particular, the prominent contribution of drainage sewer overflow pollution during storm events were investigated. The results showed that the microplastics abundance in daily sewage discharge from different drainage plots ranged between 13.6 and 30.8 items/L, with fibers as the dominant type of microplastics. Sewer overflow discharge can greatly aggravate microplastic abundance to 83.1 ± 40.2 items/L. Road runoff and sewer sediment scouring were the main pollution sources. Systematic estimates based on detailed data showed that the average microplastics emitted per capita per day in household wastewater was 3461.5 items. A quantitative estimation method was proposed to show that the annual emissions load of microplastics via urban drainage system in this research area was 5.83×1010 items/km2, of which the proportion of emissions in wet weather accounted for about 60%. This research provides the first full-process of assessment and source apportionment of the microplastic distribution characteristics in old drainage system. The occurrence of storm events is an important marker of increased microplastic abundance in urban rivers, with a view to urgent need for interception of surface runoff and purification of sewer overflow pollution.
Lake basins in Latin America face challenges in water resource management
and natural resource conservation due to changes in land use, climate variability, and governance process deficiencies. In the basins of the Escaba reservoir, Northern Argentina, droughts and floods events, decreased riparian
forest quality, and algal blooms have impacted the regulation of the ecosystem
services and socioeconomic development. To map governance, we consider the pillars of institutions and policies of the Integrated Lake Basin Management (ILBM) framework proposed by the International Lake Environment Committee. First, we quantify the institutional interaction percentage using the spatial boundaries of each institution and a spatial overlapping with geographic information systems. We measure institutions at the three levels of public administration (national, provincial and municipal) responsible for managing and administering regional water resources. Second, we compile and spatialize the most frequent water-related socio-environmental problems. Finally, we assess each hierarchical level's governance challenges and
opportunities according to the territorial scope.
The results find 21 institutions in the area. The Escaba reservoir zone has
the highest percentage of institutional interaction (91.6%) and the highest
number of problems at the same point, demonstrating a robust institutional structure; however, community participation in decision-making is needed to reinforce the pillars. Mapping governance using the spatial institution environmental problem relationships facilitates the visualization of possible
management opportunities, identifying the institutional synergies needed
to promote the ILBM framework in the basin.
The extensive use of plastics leads to the release and diffusion of microplastics. Household plastic products occupy a large part and are closely related to daily life. Due to the small size and complex composition of microplastics, it is challenging to identify and quantify microplastics. Therefore,a multi-model machine learning approach was developed for classification of household microplastics based on Raman spectroscopy. In this study, Raman spectroscopy and machine learning algorithm are combined to realize the accurate identification of seven standard microplastic samples, real microplastics samples and real microplastic samples post-exposure to environmental stresses. Four single-model machine learning methods were used in this study, including Support vector machine (SVM), K-nearest neighbor (KNN), Linear discriminant analysis (LDA), and Multi-layer perceptron (MLP) model. The principal components analysis (PCA) was utilized before SVM, KNN and LDA. The classification effect of four models on standard plastic samples is over 88%, and reliefF algorithm was used to distinguish HDPE and LDPE samples. A multi-model is proposed based on four single models including PCA-LDA, PCA-KNN and MLP. The recognition accuracy of multi-model for standard microplastic samples, real microplastic samples and microplastic samples post-exposure to environmental stresses is over 98%. Our study demonstrates that the multi-model coupled with Raman spectroscopy is a valuable tool for microplastic classification.
Municipal wastewater treatment plants act as a sink, but also are a source of microplastics in the environment. A conventional wastewater lagoon system and an activated sludge (AS)-lagoon system in Victoria (Australia) were investigated through a two-year sampling program to understand the fate and transport of MP in such treatment processes. The abundance (>25 μm) and characteristics (size, shape, and colour) of the microplastics present in the various wastewater streams were determined. The mean values of MP in the influent of the two plants were 55.3 ± 38.4 and 42.5 ± 20.1 MP/L, respectively. The dominant MP size of influent and final effluent was <500 μm, with 25-200 μm accounting for >65 % of the total MP; synthetic fibres were the dominant MP in all wastewater streams. Influent MP concentration was significantly higher in summer than in other seasons for both systems, which was related to the lower plant inflow due to less stormwater entering the sewer during summer. The promising MP removal capability of the lagoon system (97 %) was attributed to its lengthy wastewater detention time (total HRT >250 days, including the storage lagoons) that would allow effective separation of MP from the water column via various physical and biological pathways. For the AS-lagoon system, the high MP reduction efficiency (98.4 %) was attributed to the post-secondary treatment of the wastewater with the lagoon system, in which MP was further removed during the month-long detention in the lagoons. The results indicated the potential of such low-energy and low-cost wastewater treatment systems for MP control.
Purpose Soil represents a key reservoir for microplastics (MPs) in the terrestrial environment. Unfortunately, scientific endeavors on MP pollution in rural soils of coastal cities appear to be inadequate. The interconnection between rural soil MPs and potentially hazardous metals (PHMs) is underexplored. This work investigated the combined pollution of MPs and 8 PHMs (As, Cd, Cr, Cu, Zn, Pb, Hg, and Ni) in the rural soils of Xiamen, a typical coastal city in China.
Materials and methods Sixteen sites were selected based on different administrative areas and representative land use types in Xiamen for surface soil sampling. MP selection and identification were performed using a stereo light microscope and Senterra II Compact Raman Microscope. MPs were analyzed for elemental composition using scanning electron microscopy with energy dispersive X-ray spectroscopy. Soil properties and PHMs concentrations were measured using the relevant industrial and national standards.
Results and discussion The abundance of MPs ranged from 15 to 2222 items kg–1 with an average of 229 ± 523 items kg–1, suggesting that the rural soils have been widely disturbed by MP contamination. The dominant shape, color, and size of MPs were fragments (55.3%) and fibers (35.8%), transparent (59.3%) and white (17.7%), and <1 mm (64.4%), respectively. Polypropylene (67.6%) was the main polymer type, followed by polystyrene (11.0%) and polyester (9.4%). The abundance of MPs (except for the most contaminated S13) was not highly associated with PHMs contents in rural soil. The energy dispersive X-ray spectra manifested irregular distribution of Zn and Pb on the MP surfaces at site S13.
Conclusion MP pollution was widespread in rural soils in Xiamen. MPs served as the potential vector that transmitted PHMs to soils at high levels of PHMs. The rural soil MPs in Xiamen may be originated from agricultural, industrial, and human activities. This study provides insights into combined contamination of MPs and PHMs in rural soils in Xiamen, which will help formulate effective pollution abatement measures.
Microplastics (MPs) are ubiquitous, persistent pollutants reported in abundance in all environments and biota. The main objective of this review is to identify the sources, distribution, and concentration of MPs in all aquatic environments and biota in the Indian region. On sources of the Web of Science (WoS), 45 papers on MPs were published in total between 2013 and 2020. To define the concentration of MPs in different aquatic environments, 3096 items/kg in marine sediments, 106 items/kg in biota, 59 items/L in seawater, 175 items/kg in sea salt, 33.9 items/L in lake water, 336 items/kg in lake sediments, 288 pieces/m3 in river water, and 328 items/kg in river sediments were investigated in previous studies. Consequently, we studied the distribution and occurrence of pollution from MPs in coastal and freshwater environments such as rivers, lakes, and biota. Therefore, we propose extending studies in all the above areas, knowing that there are many unique aquatic habitats and species that are yet unexplored. For future research, we suggest new methods for sampling MPs in all marine ecosystems and biota. Assessing research in each of these ways will allow for suggesting a MP threshold level and devising control
initiatives to minimize plastic consumption and its eventual hazard to the aquatic ecosystem. Moreover, enforcing strict laws, enhancing legal initiatives, well-planned comprehensive waste management policies, and spontaneous public engagement is essential to create awareness of marine plastic pollution and reduce the adverse effects of land-based plastics. Marine sediments have a higher concentration of MPs than sea salt, biota, or seawater. Researchers should assess the findings in these ways to reduce plastic consumption and the threat it poses to the marine ecosystem.
Urban stormwater runoff is an important pathway for the introduction of microplastics and other anthropogenic pollutants into aquatic environments. Highly variable concentrations of microplastics have been reported globally in runoff, but knowledge of key factors within urban environments contributing to this variability remains limited. Furthermore, few studies to date have quantitatively assessed the release of microplastics to receiving waters via runoff. The objectives of this study were to assess the influence of different catchment characteristics on the type and amount of microplastics in runoff and to provide an estimate of the quantity of microplastics discharged during rain events. Stormwater samples were collected during both dry periods (baseflow) and rain events from 15 locations throughout the city of Calgary, Canada’s fourth largest city. These catchments ranged in size and contained different types of predominant land use. Microplastics were found in all samples, with total concentrations ranging from 0.7 to 200.4 pcs/L (mean = 31.9 pcs/L). Fibers were the most prevalent morphology identified (47.7 ± 33.0%), and the greatest percentage of microplastics were found in the 125–250 µm size range (26.6 ± 22.9%) followed by the 37–125 µm size range (24.0 ± 22.3%). Particles were predominantly black (33.5 ± 33.8%), transparent (22.6 ± 31.3%), or blue (16.0 ± 21.6%). Total concentrations, dominant morphologies, and size distributions of microplastics differed between rain events and baseflow, with smaller particles and higher concentrations being found during rain events. Concentrations did not differ significantly amongst catchments with different land use types, but concentrations were positively correlated with maximum runoff flow rate, catchment size, and the percentage of impervious surface area within a catchment. Combining microplastic concentrations with hydrograph data collected during rain events, we estimated that individual outfalls discharged between 1.9 million to 9.6 billion microplastics to receiving waters per rain event. These results provide further evidence that urban stormwater runoff is a significant pathway for the introduction of microplastics into aquatic environments and suggests that mitigation strategies for microplastic pollution should focus on larger urbanized catchments.
Microplastic (MP) pollution is an ongoing problem in coastal systems, where wastewater treatment plants (WWTPs) deposit particles daily. This study examined MP characteristics at WWTP outflow and control sites in St. Andrew Bay in Northwestern Florida, USA. WWTP sites contained mostly polypropylene fragments (180.1 μm avg. size), while reference sites contained polypropylene fragments, and polyethylene and polyester fibers (315.3 μm avg. size). MP sizes were strongly linked to distance from the nearest WWTP, while shape and polymer compositions were more closely related to dissolved oxygen concentrations and distance to the nearest water input source. The prevalence of polypropylene fragments at WWTP sites suggests that extreme weather events during the study flushed land-based debris into the system, where it was buried in the sediments. Increased abundances of polyester and polyethylene terephthalate in the winter at WWTP sites are indicative of the role that laundering synthetic textiles plays in coastal MP pollution.
Municipal wastewater effluent has been proposed as one pathway for microplastics to enter the aquatic environment. Here we present a broad study of municipal wastewater treatment plant effluent as a pathway for microplastic pollution to enter receiving waters. A total of 90 samples were analyzed from 17 different facilities across the United States. Averaging all facilities and sampling dates, 0.05 ± 0.024 microparticles were found per liter of effluent. Though a small value on a per liter basis, even minor municipal wastewater treatment facilities process millions of liters of wastewater each day, yielding daily discharges that ranged from ∼50,000 up to nearly 15 million particles. Averaging across the 17 facilities tested, our results indicate that wastewater treatment facilities are releasing over 4 million microparticles per facility per day. Fibers and fragments were found to be the most common type of particle within the effluent; however, some fibers may be derived from non-plastic sources. Considerable inter- and intra-facility variation in discharge concentrations, as well as the relative proportions of particle types, was observed. Statistical analysis suggested facilities serving larger populations discharged more particles. Results did not suggest tertiary filtration treatments were an effective means of reducing discharge. Assuming that fragments and pellets found in the effluent arise from the 'microbeads' found in many cosmetics and personal care products, it is estimated that between 3 and 23 billion (with an average of 13 billion) of these microplastic particles are being released into US waterways every day via municipal wastewater. This estimate can be used to evaluate the contribution of microbeads to microplastic pollution relative to other sources (e.g., plastic litter and debris) and pathways (e.g., stormwater) of discharge.
The accumulation of litter in marine and coastal environments is a major threat to marine life. Data on marine litter in the gastrointestinal tract of stranded loggerhead turtles, Caretta caretta, found along the Portuguese continental coastwas presented. Out of the 95 analysed loggerheads, litter was present in 56 individuals (59.0%) and most had less than 10 litter items (76.8%) and less than 5 g (dm) (96.8%). Plastic was the main litter category (frequency of occurrence = 56.8%), while sheet (45.3%) was the most relevant plastic sub-category. There was no influence of loggerhead stranding season, cause of stranding or size on the amount of litter ingested (mean number and dry mass of litter items per turtle). The high ingested litter occurrence frequency in this study supports the use of the loggerhead turtle as a suitable tool to monitor marine litter trends, as required by the European Marine Strategy Framework Directive.
Municipal wastewater treatment plants (WWTPs) are frequently suspected as significant point sources or conduits of microplastics to the environment. To directly investigate these suspicions, effluent discharges from seven tertiary plants and one secondary plant in Southern California were studied. The study also looked at influent loads, particle size/type, conveyance, and removal at these wastewater treatment facilities. Over 0.189 million liters of effluent at each of the seven tertiary plants were filtered using an assembled stack of sieves with mesh sizes between 400 and 45 μm. Additionally, the surface of 28.4 million liters of final effluent at three tertiary plants was skimmed using a 125 μm filtering assembly. The results suggest that tertiary effluent is not a significant source of microplastics and that these plastic pollutants are effectively removed during the skimming and settling treatment processes. However, at a downstream secondary plant, an average of one micro-particle in every 1.14 thousand liters of final effluent was counted. The majority of microplastics identified in this study had a profile (color, shape, and size) similar to the blue polyethylene particles present in toothpaste formulations. Existing treatment processes were determined to be very effective for removal of microplastic contaminants entering typical municipal WWTPs.
The ubiquity of anthropogenic debris in hundreds of species of wildlife and the toxicity of chemicals associated with it has begun to raise concerns regarding the presence of anthropogenic debris in seafood. We assessed the presence of anthropogenic debris in fishes and shellfish on sale for human consumption. We sampled from markets in Makassar, Indonesia, and from California, USA. All fish and shellfish were identified to species where possible. Anthropogenic debris was extracted from the digestive tracts of fish and whole shellfish using a 10% KOH solution and quantified under a dissecting microscope. In Indonesia, anthropogenic debris was found in 28% of individual fish and in 55% of all species. Similarly, in the USA, anthropogenic debris was found in 25% of individual fish and in 67% of all species. Anthropogenic debris was also found in 33% of individual shellfish sampled. All of the anthropogenic debris recovered from fish in Indonesia was plastic, whereas anthropogenic debris recovered from fish in the USA was primarily fibers. Variations in debris types likely reflect different sources and waste management strategies between countries. We report some of the first findings of plastic debris in fishes directly sold for human consumption raising concerns regarding human health.
Dead leaves of the Neptune grass, Posidonia oceanica (L.) Delile, in the Mediterranean coastal zone, are colonized by an abundant " detritivorous " invertebrate community that is heavily predated by fishes. This community was sampled in August 2011, November 2011, and March 2012 at two different sites in the Calvi Bay (Corsica). Ingested artificial fibers (AFs) of various sizes and colors were found in 27.6% of the digestive tracts of the nine dominant species regardless of their trophic level or taxon. No seasonal, spatial, size, or species-specific significant differences were revealed; suggesting that invertebrates ingest AFs at constant rates. Results showed that, in the gut contents of invertebrates, varying by trophic level, and across trophic levels, the overall ingestion of AFs was low (approximately 1 fiber per organism). Raman spectroscopy revealed that the ingested AFs were composed of viscose, an artificial, cellulose-based polymer. Most of these AFs also appeared to have been colored by industrial dyes. Two dyes were identified: Direct Blue 22 and Direct Red 28. The latter is known for being carcinogenic for vertebrates, potentially causing environmental problems for the P. oceanica litter community. Techniques such as Raman spectroscopy are necessary to investigate the particles composition, instead of relying on fragment size or color to identify the particles ingested by animals.
Fulmars are effective biological indicators of the abundance of floating plastic marine debris. Long-term data reveal high plastic abundance in the southern North Sea, gradually decreasing to the north at increasing distance from population centres, with lowest levels in high-arctic waters. Since the 1980s, pre-production plastic pellets in North Sea fulmars have decreased by ∼75%, while user plastics varied without a strong overall change. Similar trends were found in net-collected floating plastic debris in the North Atlantic subtropical gyre, with a ∼75% decrease in plastic pellets and no obvious trend in user plastic. The decreases in pellets suggest that changes in litter input are rapidly visible in the environment not only close to presumed sources, but also far from land. Floating plastic debris is rapidly "lost" from the ocean surface to other as-yet undetermined sinks in the marine environment.
Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
Although widely detected in marine ecosystems, microplastic pollution has only recently been documented in freshwater environments, almost exclusively in surface waters. Here, we report microplastics (polyethylene microbeads, 0.40–2.16 mm diameter) in the sediments of the St. Lawrence River. We sampled ten freshwater sites along a 320-km section from Lake St. Francis to Québec City, by passing sediment collected from a benthic grab through a 500μm sieve. Microbeads were discovered throughout this section and their abundances varied by four orders of magnitude across sites. Median and mean (±1 S.E.) densities across sites were 52 microbeads m**-2 and 13 832 (± 13677) microbeads m**-2, respectively. The highest site density was 1.4 × 10**5 microbeads m**-2 (or 10**3 microbeads L**-1), which is similar in magnitude to microplastic concentrations found in the most contaminated marine sediments. Mean diameter of microbeads was smaller at sites receiving municipal or industrial effluent (0.70 ± 0.01 mm) than at non-effluent sites (0.98 ± 0.01 mm), perhaps suggesting differential origins. Given the prevalence and locally high densities of microplastics in St. Lawrence River sediments, their ingestion by benthivorous fishes and macroinvertebrates warrants investigation.
Suspended microplastic and black carbon (BC) particles were determined in surface waters of the Jade system, southern North Sea, including freshwater sources. On average, 64 ± 194 granular particles, 88 ± 82 fibres and 30 ± 41 BC particles/L were recorded. Maximum numbers reached 1,770/L for granules, 650/L for fibres and 330/L for black carbon particles. The distribution along a transect from the inner to the outer part of the Jade system indicates granular particles to be dominant in the inner part, while fibres occur more prominently in the outer part. The distribution of BC particles was more uniform. All freshwater sources including sewage treatment plant effluents discharged microplastics, while BC was encountered only at two of nine discharge points.
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.
This review of 68 studies compares the methodologies used for the identification and quantification of microplastics from the marine environment. Three main sampling strategies were identified: selective, volume-reduced, and bulk sampling. Most sediment samples came from sandy beaches at the high tide line, and most seawater samples were taken at the sea surface using neuston nets. Four steps were distinguished during sample processing: density separation, filtration, sieving, and visual sorting of microplastics. Visual sorting was one of the most commonly used methods for the identification of microplastics (using type, shape, degradation stage, and color as criteria). Chemical and physical characteristics (e.g., specific density) were also used. The most reliable method to identify the chemical composition of microplastics is by infrared spectroscopy. Most studies reported that plastic fragments were polyethylene and polypropylene polymers. Units commonly used for abundance estimates are "items per m(2)" for sediment and sea surface studies and "items per m(3)" for water column studies. Mesh size of sieves and filters used during sampling or sample processing influence abundance estimates. Most studies reported two main size ranges of microplastics: (i) 500 μm-5 mm, which are retained by a 500 μm sieve/net, and (ii) 1-500 μm, or fractions thereof that are retained on filters. We recommend that future programs of monitoring continue to distinguish these size fractions, but we suggest standardized sampling procedures which allow the spatiotemporal comparison of microplastic abundance across marine environments.
Plastics have transformed everyday life; usage is increasing and annual production is likely to exceed 300 million tonnes by 2010. In this concluding paper to the Theme Issue on Plastics, the Environment and Human Health, we synthesize current understanding of the benefits and concerns surrounding the use of plastics and look to future priorities, challenges and opportunities. It is evident that plastics bring many societal benefits and offer future technological and medical advances. However, concerns about usage and disposal are diverse and include accumulation of waste in landfills and in natural habitats, physical problems for wildlife resulting from ingestion or entanglement in plastic, the leaching of chemicals from plastic products and the potential for plastics to transfer chemicals to wildlife and humans. However, perhaps the most important overriding concern, which is implicit throughout this volume, is that our current usage is not sustainable. Around 4 per cent of world oil production is used as a feedstock to make plastics and a similar amount is used as energy in the process. Yet over a third of current production is used to make items of packaging, which are then rapidly discarded. Given our declining reserves of fossil fuels, and finite capacity for disposal of waste to landfill, this linear use of hydrocarbons, via packaging and other short-lived applications of plastic, is simply not sustainable. There are solutions, including material reduction, design for end-of-life recyclability, increased recycling capacity, development of bio-based feedstocks, strategies to reduce littering, the application of green chemistry life-cycle analyses and revised risk assessment approaches. Such measures will be most effective through the combined actions of the public, industry, scientists and policymakers. There is some urgency, as the quantity of plastics produced in the first 10 years of the current century is likely to approach the quantity produced in the entire century that preceded.
Plastics debris is accumulating in the environment and is fragmenting into smaller pieces; as it does, the potential for ingestion by animals increases. The consequences of macroplastic debris for wildlife are well documented, however the impacts of microplastic (< 1 mm) are poorly understood. The mussel, Mytilus edulis, was used to investigate ingestion, translocation, and accumulation of this debris. Initial experiments showed that upon ingestion, microplastic accumulated in the gut. Mussels were subsequently exposed to treatments containing seawater and microplastic (3.0 or 9.6 microm). After transfer to clean conditions, microplastic was tracked in the hemolymph. Particles translocated from the gut to the circulatory system within 3 days and persisted for over 48 days. Abundance of microplastic was greatest after 12 days and declined thereafter. Smaller particles were more abundant than larger particles and our data indicate as plastic fragments into smaller particles, the potential for accumulation in the tissues of an organism increases. The short-term pulse exposure used here did not result in significant biological effects. However, plastics are exceedingly durable and so further work using a wider range of organisms, polymers, and periods of exposure will be required to establish the biological consequences of this debris.
Yes, we are eating plastic-ingesting fish. A baseline assessment of plastic pellet ingestion by two species of important edible fish caught along the eastern coast of Brazil is described. The rate of plastic ingestion by king mackerel (Scomberomorus cavalla) was quite high (62.5%), followed by the Brazilian sharpnose shark (Rhizoprionodon lalandii, 33%). From 2 to 6 plastic resin pellets were encountered in the stomachs of each fish, with sizes of from 1 to 5 mm, and with colors ranging from clear to white and yellowish. Ecological and health-related implications are discussed and the potential for transferring these materials through the food-chain are addressed. Further research will be needed of other species harvested for human consumption.
Microplastics, degraded and weathered polymer-based particles, and manufactured products ranging between 50 and 5000 μm in size, are found within marine, freshwater, and estuarine environments. While numerous peer-reviewed papers have quantified the ingestion of microplastics by marine vertebrates, relatively few studies have focused on microplastic ingestion by freshwater organisms. This study documents microplastic and manufactured fiber ingestion by bluegill (Lepomis macrochirus) and longear (Lepomis megalotis) sunfish (Centrarchidae) from the Brazos River Basin, between Lake Whitney and Marlin, Texas, USA. Fourteen sample sites were studied and categorized into urban, downstream, and upstream areas. A total of 436 sunfish were collected, and 196 (45%) stomachs contained microplastics. Four percent (4%) of items sampled were debris on the macro size scale (i.e. >5 mm) and consisted of masses of plastic, metal, Styrofoam, or fishing material, while 96% of items sampled were in the form of microplastic threads. Fish length was statistically correlated to the number of microplastics detected (p = 0.019). Fish collected from urban sites displayed the highest mean number of microplastics ingested, followed by downstream and upstream sites. Microplastics were associated with the ingestion of other debris items (e.g. sand and wood) and correlated to the ingestion of fish eggs, earthworms, and mollusks, suggesting that sunfish incidentally ingest microplastics during their normal feeding methods. The high frequency of microplastic ingestion suggest that further research is needed to determine the residence time of microplastics within the stomach and gut, potential for food web transfer, and adverse effects on wildlife and ecosystemic health.
Yes, we are eating plastic-ingesting fish. A baseline assessment of plastic pellet ingestion by two species of important edible fish caught along the eastern coast of Brazil is described. The rate of plastic ingestion by king mackerel (Scomberomorus cavalla) was quite high (62.5%), followed by the Brazilian sharpnose shark (Rhizoprionodon lalandii, 33%). From 2 to 6 plastic resin pellets were encountered in the stomachs of each fish, with sizes of from 1 to 5 mm, and with colors ranging from clear to white and yellowish. Ecological and health-related implications are discussed and the potential for transferring these materials through the food-chain are addressed. Further research will be needed of other species harvested for human consumption.
Plastic is a common item in marine environments. Studies assessing seabird ingestion of plastics have focused on species that ingest plastics mistaken for prey items. Few studies have examined a scavenger and predatory species that are likely to ingest plastics indirectly through their prey items, such as the great skua (Stercorarius skua). We examined 1034 regurgitated pellets from a great skua colony in the Faroe Islands for plastics and found approximately 6% contained plastics. Pellets containing remains of Northern fulmars (Fulmarus glacialis) had the highest prevalence of plastic. Our findings support previous work showing that Northern fulmars have higher loads of plastics than other sympatric species. This study demonstrates that marine plastic debris is transferred from surface feeding seabird species to predatory great skuas. Examination of plastic ingestion in species that do not ingest plastics directly can provide insights into how plastic particles transfer vertically within the food web.
Dead leaves of the Neptune grass, Posidonia oceanica (L.) Delile, in the Mediterranean coastal zone, are colonized by an abundant " detritivorous " invertebrate community that is heavily predated by fishes. This community was sampled in August 2011, November 2011, and March 2012 at two different sites in the Calvi Bay (Corsica). Ingested artificial fibers (AFs) of various sizes and colors were found in 27.6% of the digestive tracts of the nine dominant species regardless of their trophic level or taxon. No seasonal, spatial, size, or species-specific significant differences were revealed; suggesting that invertebrates ingest AFs at constant rates. Results showed that, in the gut contents of invertebrates, varying by trophic level, and across trophic levels, the overall ingestion of AFs was low (approximately 1 fiber per organism). Raman spectroscopy revealed that the ingested AFs were composed of viscose, an artificial, cellulose-based polymer. Most of these AFs also appeared to have been colored by industrial dyes. Two dyes were identified: Direct Blue 22 and Direct Red 28. The latter is known for being carcinogenic for vertebrates, potentially causing environmental problems for the P. oceanica litter community. Techniques such as Raman spectroscopy are necessary to investigate the particles composition, instead of relying on fragment size or color to identify the particles ingested by animals.
This study assessed the capability of Crangon crangon (L.), an ecologically and commercially important crustacean, of consuming plastics as an opportunistic feeder. We therefore determined the microplastic content of shrimp in shallow water habitats of the Channel area and Southern part of the North Sea. Synthetic fibers ranging from 200 µm up to 1000 µm size were detected in 63 % of the assessed shrimp and an average value of 0.68 ± 0.55 microplastics/ g w. w. (1.23 ± 0.99 microplastics/ shrimp) was obtained for shrimp in the sampled area. The assessment revealed no spatial patterns in plastic ingestion, but temporal differences were reported. The microplastic uptake was significantly higher in October compared to March. The results suggest that microplastics > 20 µm are not able to translocate into the tissues.
This study assessed the capability of Crangon crangon (L.), an ecologically and commercially important crustacean, of consuming plastics as an opportunistic feeder. We therefore determined the microplastic content of shrimp in shallow water habitats of the Channel area and Southern part of the North Sea. Synthetic fibers ranging from 200 μm up to 1000 μm size were detected in 63% of the assessed shrimp and an average value of 0.68 ± 0.55 microplastics/g w. w. (1.23 ± 0.99 microplastics/shrimp) was obtained for shrimp in the sampled area. The assessment revealed no spatial patterns in plastic ingestion, but temporal differences were reported. The microplastic uptake was significantly higher in October compared to March. The results suggest that microplastics >20 μm are not able to translocate into the tissues.
This study focuses, for the first time, on the presence of plastic debris in the stomach contents of large pelagic fish (Xiphias gladius, Thunnus thynnus and Thunnus alalunga) caught in the Mediterranean Sea between 2012 and 2013. Results highlighted the ingestion of plastics in the 18.2% of samples. The plastics ingested were microplastics (<5mm), mesoplastics (5-25mm) and macroplastics (>25mm). These preliminary results represent an important initial phase in exploring two main ecotoxicological aspects: (a) the assessment of the presence and impact of plastic debris on these large pelagic fish, and (b) the potential effects related to the transfer of contaminants on human health.
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Plastics can be found in food packaging, shopping bags, and household items, such as toothbrushes and pens, and facial cleansers. Due to the high disposability and low recovery of discharged materials, plastics materials have become debris accumulating in the environment. Microplastics have a dimension <5 mm and possess physico-chemical properties (e.g., size, density, color and chemical composition) that are key contributors to their bioavailability to organisms. This review addresses the analytical approaches to characterization and quantification of microplastics in the environment and discusses recent studies on their occurrence, fate, and behavior. This critical overview includes a general assessment of sampling and sample handling, and compares methods for morphological and physical classification, and methodologies for chemical characterization and quantification of the microplastics. Finally, this review addresses the advantages and the disadvantages of these techniques, and comments on future applications and potential research interest within this field.
Once believed to degrade into simple compounds, increasing evidence suggests plastics entering the environment are mechanically, photochemically and/or biologically degraded to the extent that they become imperceptible to the naked eye yet are not significantly reduced in total mass. Thus, more and smaller plastics particles, termed microplastics, reside in the environment and are now a contaminant category of concern. The current study tested the hypotheses that microplastics concentration would be higher in proximity to urban sources, and vary temporally in response to weather phenomena such as storm events. Triplicate surface water samples were collected approximately monthly between July and December 2011 from four estuarine tributaries within the Chesapeake Bay, USA using a manta net to capture appropriately sized microplastics (operationally defined as 0.3‒5.0 mm). Selected sites have watersheds with broadly divergent land use characteristics (e.g., proportion urban/suburban, agricultural and/or forested) and wide ranging population densities. Microplastics were found in all but one of 60 samples with concentrations ranging over three orders of magnitude (<1.0 to > 560 g/km(2)). Concentrations demonstrated statistically significant positive correlations with population density and proportion of urban/suburban development within watersheds. Greatest microplastics concentrations also occurred at three of four sites shortly after major rain events.
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.
Neuston samples were collected at 21 stations during an ∼700 nautical mile (∼1300 km) expedition in July 2012 in the Laurentian Great Lakes of the United States using a 333 μm mesh manta trawl and analyzed for plastic debris. Although the average abundance was approximately 43,000 microplastic particles/km2, station 20, downstream from two major cities, contained over 466,000 particles/km2, greater than all other stations combined. SEM analysis determined nearly 20% of particles less than 1 mm, which were initially identified as microplastic by visual observation, were aluminum silicate from coal ash. Many microplastic particles were multi-colored spheres, which were compared to, and are suspected to be, microbeads from consumer products containing microplastic particles of similar size, shape, texture and composition. The presence of microplastics and coal ash in these surface samples, which were most abundant where lake currents converge, are likely from nearby urban effluent and coal burning power plants.
Plastics pollution in the ocean is an area of growing concern, with research efforts focusing on both the macroplastic (>5 mm) and microplastic (<5 mm) fractions. In the 1990s it was recognized that a minor source of microplastic pollution was derived from liquid hand-cleansers that would have been rarely used by the average consumer. In 2009, however, the average consumer is likely to be using microplastic-containing products on a daily basis, as the majority of facial cleansers now contain polyethylene microplastics which are not captured by wastewater plants and will enter the oceans. Four microplastic-containing facial cleansers available in New Zealand supermarkets were used to quantify the size of the polythelene fragments. Three-quarters of the brands had a modal size of <100 microns and could be immediately ingested by planktonic organisms at the base of the food chain. Over time the microplastics will be subject to UV-degradation and absorb hydrophobic materials such as PCBs, making them smaller and more toxic in the long-term. Marine scientists need to educate the public to the dangers of using products that pose an immediate and long-term threat to the health of the oceans and the food we eat.