Majority Of Microplastics Research Articles

Microplastics in an advanced wastewater treatment plant: sustained and robust removal rates unfazed by seasonal variations

Microplastics (MP), fragments of plastic generally defined as, less than 5 mm in size, originating from various urban sources, have become a significant environmental concern due to their widespread presence and potential impacts on ecosystems. This study investigates the efficiency of an advanced wastewater treatment plant discharging into the Mediterranean Sea in removing MPs from wastewater. The plant processes wastewater through a series of treatment stages, including screening, desanding, coagulation/flocculation, biological filtration, and sludge incineration. Samples were collected and analysed during three distinct campaigns (dry, rainy, and touristic seasons) to assess the plant’s performance under varying conditions. Using matrix-representative sampling methodologies and Focal Plane Array micro Fourier-Transform Infrared Spectroscopy (FPA-µFT-IR) for MP quantification, the study measured MP concentrations and removal rates. The treatment plant demonstrated high removal rates of microplastics across different periods. Using a mass balance approach, the removal efficiency during the dry sampling period was 99.85%. In the rainy campaign, the efficiency slightly decreased to 99.11% due to increased runoff, while during the touristic period, the efficiency peaked at 99.95%. Polyester was identified as the predominant polymer type. The primary treatment stages, particularly coagulation/flocculation and lamellar settling, are most effective in MP removal. The majority of MPs are retained in the sludge, which is subsequently incinerated, preventing environmental discharge. This research demonstrates that a WWTP employing advanced treatment processes is not a source of MP to the environment but rather a sink. Despite variations in influent MP concentrations across different seasons, the plant consistently maintained high removal rates, effectively mitigating MP pollution. In this study, sludge incineration further ensured that MPs were prevented from entering the environment.

Invisible threat to mesopelagic fish: Microplastics and artificial cellulose particles in bigfin lanternfish Symbolophorus californiensis from the Northwest Pacific Ocean

Lanternfishes play an important role in connecting epipelagic and mesopelagic ecosystems. Due to their global distribution, diel vertical migration, and low trophic position, they may be highly susceptible to the ingestion of microplastics (MPs) and artificial cellulose particles (ACs). However, the role of lanternfishes in these emergent pollution research remains underestimated. In this study, we compared the abundance and characteristics of MPs and ACs in the stomach and intestine of bigfin lanternfish (Symbolophorus californiensis) from the Northwest Pacific Ocean. The results showed no difference in the abundance and size of MPs between the stomach (0.28 ± 0.63 items/individual, 103.72–2946.58 μm) and intestine (0.32 ± 0.56 items/individual, 122.03–4398.17 μm). The majority of MPs were fibrous in shape, with blue and transparent being the predominant colors. Polyester (28.2 %) and polyethylene terephthalate (20.5 %) were the most common polymer types. ACs were also primary in the shape of fiber (93.2 %), with transparent being the predominant color. The abundance of ACs in the intestine (0.49 ± 0.83 items/individual) was significantly higher than that in the stomach (0.18 ± 0.43 items/individual), while similar particle sizes were observed. This study provides an important baseline on lanternfishes contamination by MPs and ACs. Understanding this impact of mesopelagic fish is crucial for enhancing our comprehension of the vertical transfer mechanism of these pollutants between epipelagic and mesopelagic ecosystems.

Quantifying microplastics in sediments of Jinzhou Bay, China: Characterization and ecological risk with a focus on small sizes

Small-sized microplastics (MPs) pose greater ecological toxicity due to their larger surface area, which makes them more likely to act as carriers for other pollutants and to be ingested by aquatic organisms. However, traditional visual analysis often neglects small-sized MPs and their associated ecological risk. This study utilized Laser Direct Infrared (LDIR) spectroscopy and traditional visual analysis to examine MPs in 31 sediment samples from Jinzhou Bay, a typical semi-enclosed bay located at the economic center of Dalian, China. The results showed significant heterogeneity in MP distribution, with averages of 1192 and 2361 items/kg dry weight reported by visual analysis and LDIR spectroscopy, respectively. LDIR spectroscopy identified MPs as small as 10 μm, with the majority of MPs (89.21 %) within the 10–250 μm range, and a significant proportion (46.45 %) between 10 and 50 μm among them. However, visual analysis was limited to detecting MPs >50 μm, and significant portions were identified between 50 and 100 μm (49.36 %) and 100–250 μm (31.01 %), missing a substantial fraction of smaller MPs. The predominant polymers identified were polyamide (PA), polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and acrylonitrile butadiene styrene (ABS). LDIR spectroscopy demonstrated a strong positive correlation between MP abundance and clay content, a relationship not observed with traditional visual analysis. The Potential Ecological Risk Index (PERI) indicated that over 87 % of sites posed an extremely high risk according to LDIR spectroscopy, compared to 51 % by traditional visual analysis. These discrepancy underscores the underestimation of ecological risks by traditional methods, particularly for small-sized MPs. High-risk polymers such as polyvinyl chloride (PVC), ABS, and polyurethane (PUR) significantly influenced PERI values. These findings highlight the critical need for precise identification and thorough risk assessment of small-sized MPs in environmental studies and offer insights for understanding of MP vertical migration in aquatic environments, particularly in the context of co-settlement with sediments.

Spatial and temporal trends in microplastic pollution in the Eastern Oyster, Crassotrea virginica, in Tampa Bay, Florida

Microplastic pollution is an increasingly alarming concern with widespread global distribution in aquatic environments. Spatial and temporal differences in microplastic abundance were evaluated in the Eastern Oyster, Crassostrea virginica, at six sites within Tampa Bay. Oyster tissue was digested using 30 % hydrogen peroxide (H2O2) and microplastics were quantified using Nile Red stain and fluorescent particle excitement. A total of 3025 microplastics were found throughout six study sites over two seasons (winter 2021 and summer 2022) with varying site types. Microfragments (n=2867) made up the majority of microplastics, as compared to microfibers (n=158). Significant differences were observed among the sites studied, site type, and their location in the bay. Outflow and marina areas had significantly higher (p<0.01) amounts of microplastics compared to preserve areas, and the east bay had significantly higher (p<0.05) amounts than the west bay. Findings suggest microplastic contamination is associated with higher urbanization, proximity to drainage basins, and recreation.

The Duration of Dry Events Promotes PVC Film Fragmentation in Intermittent Rivers.

The majority of microplastics (MPs) found in the environment originate from plastic fragmentation occurring in the environment and are influenced by environmental factors such as UV irradiation and biotic interactions. However, the effects of river drying on plastic fragmentation remain unknown, despite the global prevalence of watercourses experiencing flow intermittence. This study investigates, through laboratory experiments, the coupled effects of drying duration and UV irradiation on PVC film fragmentation induced by artificial mechanical abrasion. This study shows that PVC film fragmentation increases with drying duration through an increase in the abundance and size of formed MPs as well as mass loss from the initial plastic item, with significant differences for drying durations >50% of the experiment duration. The average abundance of formed MPs in treatments exposed to severe drying duration was almost two times higher than in treatments nonexposed to drying. Based on these results, we developed as a proof of concept an Intermittence-Based Plastic Fragmentation Index that may provide insights into plastic fragmentation occurring in river catchments experiencing large hydrological variability. The present study suggests that flow intermittence occurring in rivers and streams can lead to increasing plastic fragmentation, unraveling new insights into plastic pollution in freshwater systems.

Contamination, morphological and chemical characterization, and hazard risk analyses of microplastics in drinking water sourced from groundwater in a developing nation

Groundwater (GW) plays a crucial role as the primary source of potable water in numerous developing nations. However, the increasing presence of microplastics (MPs) represents a concealed danger, threatening activities that guarantee safe drinking water in these countries. Despite this, there is limited awareness about the widespread existence of MPs in these regions of the world. In this study, we investigated the contamination levels, distribution, morphological characteristics, chemical composition, and associated public health risk of MPs in groundwater samples from six coastal districts of Bangladesh using stereomicroscopy and Fourier transform infrared spectroscopy (FTIR). MPs were prevalent at all sampling stations, with average concentrations of 24.63 ± 16.13 items/L and a range of 4–75 items/L. The majority of MPs (97.6%) were fibers, indicating a likely origin from fabric disintegration during drying, washing, discarded fishing nets, personal care items, and municipal waste. Smaller-sized MPs (&amp;lt;0.5 mm), transparent and violet-colored, were predominantly observed. Additionally, FTIR confirmed the presence of plastic polymers, including low-density polyethylene (LDPE), high-density polyethylene (HDPE), ethylene vinyl acetate (EVA), and polyethylene terephthalate (PETE). Despite the high visibility observed or focus given for PETE, PE was found to be abundant. These are thought to have come from runoff from agricultural fields, seeping from landfills where plastic trash is disposed of, synthetic fabrics, and inappropriate plastic product disposal. Estimated dietary intake was recorded as 1.85 particles/person/day (i.e., 675 particles/year), suggesting the possible health risk to consumers. Hazard analyses based on the polymeric risk score revealed diverse risks associated with polymer levels, with PETE indicating a medium risk and other polymers, e.g., HDPE, LDPE, and EVA at 39%, 31%, and 17%, respectively, showing a minor risk to human health from drinking water from the studied sources. This is the first study from the regions, and the findings will be valuable for identifying sources, implementing control measures, shaping policies, and safeguarding public health against plastic pollution.

Effect of particle density on microplastics transport in artificial and natural porous media

The occurrence and persistence of microplastics (MPs) in natural environments are of increasing concern. Along with this, the transport of MPs in sediments has been investigated mainly focusing on the effect of plastic size and shape, media size effect, and solution chemistry. Yet, the influence of particle density is only partially understood. Therefore, column experiments on the transport of variably buoyant MPs in saturated natural sediments and glass beads were conducted, and transport parameters were quantified using a two-site kinetic transport model with a depth-dependent blocking function (the amount of retained MPs does not decrease at a constant rate with increasing depth, the majority of MPs were retained near the column inlet). Neutral, sinking, and buoyant MPs within the same size range were selected, with stable water isotope applied as conservative tracer to explore water and MP movement in the tested sediments. The results showed that 95.5 ± 1.4% of sinking MPs remained in columns packed with gravel, followed by buoyant and neutral MPs, thus indicating that particle density does affect MP mobility. Similar recovered amounts of MPs were found in columns packed with glass beads, indicating that tested sediment types do not affect the deposition behavior of MPs. The breakthrough curves of MPs were accurately described by the selected model. However, the simulated retention profiles overestimated the observed MP amount in layers closest to the column inlet. The coupled experimental and modeled results suggest an enhanced retention of sinking MPs, while neutrally and buoyant MPs exhibit a higher mobility in comparison. Thus, neutral or buoyant MPs can potentially pose a higher contamination risk to subsurface porous media environments compared to sinking MPs. Discrepancies between observed and simulated retention profiles indicate that future model development is needed for advancing the MP deposition as affected by particle density.

A review on the presence of microplastics in environmental matrices within Southeast Asia: elucidating risk information through an analysis of microplastic characteristics such as size, shape, and type

Microplastics’ ecotoxicological potential in almost all ecosystems makes them a global environmental issue. This review evaluates Southeast Asian microplastic contamination data from 2013 to 2023. This evaluation examined 285 research publications from Scopus, Web of Science, and ScienceDirect, mostly on sediment and water matrices. Based on their size, shape, polymer type, and potential risks from polymer hazards in Southeast Asian countries, this analysis assesses microplastic pollution in biota, sediment, water, and other environmental matrices. The majority of microplastics in this region are small (46%) and large (32%). Within the biota matrix, small microplastics (SMP) and large microplastics (LMP) dominated. Fibers predominated in all matrices, particularly the biota matrix. Polyethylene emerged as the most abundant polymer type (22%), found in all four matrices. Despite being less abundant, polyurethane and polyamide have high hazard scores, raising ecological concerns due to their detrimental effects on environmental matrices. According to the analyzed data, Southeast Asian countries face significant risks due to high levels of microplastic contamination in water, sediments, biota, and other matrices. However, there are noticeable discrepancies in Southeast Asian data, indicating progress in microplastic research, with most data coming from Indonesia, Thailand, Malaysia, Vietnam, and the Philippines and little information in the literature regarding microplastic contamination from East Timor, Laos, Brunei, Myanmar, and Cambodia.

Microplastics abundance in sea cucumber Holothuria scabra from Pulau Malawali, Sabah, Malaysia

The growing amount of plastic waste in the environment is a result of the increased use of plastics in numerous areas of our daily lives. These plastics are broken down into microplastics (MPs), which are 5 mm or smaller in size. Sea cucumbers are consumed as an exotic delicacy worldwide, however, it is suspected that they could ingest the microplastics due to their nature as filter feeder. In this study, we have identified the MPs presence in the intestines of sea cucumber Holothuria scabra. A total of 30 sea cucumber H. scabra were collected during low tide at a muddy sandy area at Pulau Malawali using bare hands. The gastrointestinal tracts of H. scabra were removed and digested in NaOH. MPs were identified using light microscope and categorized into shapes and colours. Micro-Fourier Transform-Infrared Spectroscopy (µFTIR) analysis was carried out to identify the types of polymers. The majority colours of MPs were black (69.84%) and blue (18.65%). Fibres (98.38%) made up the majority of MPs followed by fragments (1.37%) and films (0.25%). Ethylene Vinyl Acetate (EVA), Melamine-Formaldehyde (MF) and Rayon were among the polymers identified. In conclusion, MPs were found in the intestines of the sea cucumber H. scabra and this could be from the ingestion of polluted sea bed. The importance of studying the presence of these MPs in sea cucumber allows us to assess the impact of plastic pollution on marine animals and ecosystems and understand the potential risks to both sea cucumber and human as consumers.

Microplastics in indoor deposition samples in university classrooms

The pollution caused by microplastics (MPs) is a growing concern on a global scale, especially considering the significant proportion of time that individuals spend indoors. The contamination in question has the potential to directly impact the human population through exposure to indoor dust and air. This research undertook a comprehensive analysis of the indoor deposition of MPs in university classrooms, employing various investigative tools. The present study aimed to comprehensively analyze the physical and chemical properties of MPs found in university classrooms. Analyzing samples under a stereomicroscope, the predominant MPs were identified as fibers of varied colors, mainly attributed to clothing. Sizes of these MPs varied significantly across different classrooms, with a general average size range of 120–2222 µm. The observed morphological changes in MPs, including cracks and grooves, hint at potential degradation into nanosized plastics over time. This observation raises concerns about increased concentrations of nanoplastics in indoor environments. Using µRaman analysis, eleven types of MPs were identified, potentially originating from clothing, shoes, and stationery. The majority of MPs were polyamide 6, polypropylene, and polyamide 12. The scanning electron microscope and energy-dispersive X-ray spectroscopy (SEM–EDX) technique unveiled the elemental composition of the MPs, with carbon, fluorine, and oxygen being dominant. The findings align with past studies but highlight the need to understand MPs' structural components and any possible contaminants. Compared to existing literature, this study adopts a comprehensive methodological approach combining optical microscopy, µRaman, and SEM–EDX, enriching the knowledge on indoor MP deposition and aiding future research directions.

Assessment of microplastic contamination in commercially available fishes

Plastics have widespread applications for human use, but their disposal poses a significant threat to living organisms and these plastics end up in the marine environment. They will be fragmented into small pieces as a result of ultraviolet exposure, climatic changes, and temperature changes; Microplastics (MPs) are plastics that are less than 5 mm in size. The level of MP (Microplastic) pollution in commercially harvested fish from different habitant in Vellore, India is currently unknown. Therefore, this study aimed to determine the presence and characteristics of ingested or inhaled MPs in marine and freshwater fishes highly consumed by the local population. Fish gills and gastrointestinal tracts were aseptically dissected and digested (30% hydrogen peroxide), then filtered and examined under a microscope for the presence of MPs. Further analysis was performed on the samples using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray (EDAX). Of the samples analysed, a total of 875 MPs were recovered from 32 fishes, with 478 from marine fishes and 397 from freshwater fishes. The most common colours of the MPs were blue and black, while stereo microscopy analysis revealed that the majority of MPs were fibers (91%), followed by fragments (8%) and a small number of films. The ATR-FTIR analysis identified polyvinyl alcohol (39.76%), polyethylene (16.51%), methylcellulose (12.84%) and styrene (9.07%), as the predominant types of MPs in the fish samples. This study highlights the significant impact of MP pollution on marine ecosystems. The research provides insight into the nature and extent of MPs in fish from both marine and freshwater habitats, with an aim for policies and interventions aimed to reduce plastic pollution in the locality.

Microplastics Isolated from Saltwater Clam Paratapes undulatus from Wet Market at Shah Alam, Selangor, Malaysia

Plastic waste has become a serious environmental threat because of large scale demand and poor disposal methods. Microplastics, defined defined as plastic waste with a diameter spanning from 5 mm to 1 μm, may easily enter the ocean and cumulatively ingested by marine life, which will eventually be consumed by humans. The goal of this study is to determine the types of microplastic that can be found in the saltwater clam Paratapes undulatus collected in Kuala Selangor, a fishery hub in Peninsular Malaysia. A total of 30 P. undulatus samples were collected and the soft tissue inside was dissected and digested using NaOH. The digestates were then vacuum-filtered to obtain the microplastics. Microplastics were identified based on their physical characteristics under microscopic examination (colour, shape and size). Fourier Transform Infrared Spectroscopy (FTIR) was used to determine the polymers based on the functional group of the plastics’ molecular structure. A total of 2,072 microplastic particles were isolated from all clam samples. In terms of colour and shape, the majority of microplastics were black (64.48 %) and in the form of fibres (97.2 %). Most of the microplastic particles had sizes ranging from 0.5 to 1 µm and 1 to 2 µm. Polystyrene (PS) and polymethyl methacrylate (PMMA) were two common polymers. This study indicates that clams harvested off the coast Kuala Selangor may be contaminated with microplastics from their habitat. More research is needed to assess the toxicity and potential threat of microplastics to human health when consuming seafood.

Distribution of microplastics in seafloor sediments and their differential assimilation in nearshore benthic molluscs along the south-west coast of India

Spatial and temporal distribution of microplastics (MPs) in the nearshore seafloor sediments along the Southwest coast of India and their patterns of accumulation in selected infaunal and epibenthic molluscs with diverse feeding strategies were investigated. Along the 300-km coastal stretch, which is one of the most productive and biodiversity rich regions of the eastern Arabian Sea, notable levels of MP contamination in both sediment (617.7 items/kg dry weight) and molluscs (5.39 items/g) was recorded. The concentration of MPs in sediments also varied seasonally, with a higher prevalence during the post-monsoon season. Among the four molluscan groups studied, the highest MP abundance was recorded among scavenging gastropod Pseudominolia biangulosa (9.13 items/g), followed by microcarnivore scaphopod Tesseracme quadrapicalis (5.96 items/g). In comparison, the suspension feeding bivalve, Anadara hankeyana and deposit feeding clam Jitlada philippinarum had lesser accumulation of MPs (2.98 items/g and 3.50 items/g respectively). The majority of MPs in sediments and within molluscs were less than 250 μm in size (89.14%) and were predominantly fibres and fragments. Chemical characterisation of MPs revealed eleven types of polymers dominated by polyethylene (PE) and polypropylene (PP). Present study identified positive correlations between ingested MP polymers and the feeding strategies of molluscs. Higher values for the ecological risk assessment indices (PHI, PLI and PERI) in most of the stations indicated the severity of plastic pollution in the region. Molluscs being a major contributor to the benthic food web is also a connecting link to higher trophic levels. Hence understanding the specificity in the MPs accumulation pattern within this group has far reaching significance in utilizing them as potential bioindicators for pollution studies in marine ecosystems.

The spatial distribution and physico-chemical characteristic of microplastics in the sediment and cockle (Anadara granosa) from the coastal waters of East Java, Indonesia, and the health hazards associated with cockle consumption

This study evaluated microplastic (MP) abundances and physico-chemical characteristics in sediments and Anadara granosa along the East Java coast and their health implications. Fibers (74 %) dominated sediment MPs at south coast, while fragments (49–61 %) dominated north coast. Fiber (43–52 %) is the predominant MP in cockle tissues in all locations. Most MP in sediments (31–47 %) and cockle tissues (41–49 %) is black. The majority of microplastics (100–1500 μm) are found in sediment (73–90 %), and cockles (77–79 %). Very weak correlations found between the amount of MP and the length of the cockle shell. However, Spearman correlation shows that as the amount of MP in sediment increases, so does the amount of MP in cockle tissue. Each year, individuals of varying ages consume an average of 20,800 to 156,000 MP items. Cockles contain plasticizer components and microplastic polymers which are classified from II to V regarding of hazard levels, with V being the most hazardous.

Microplastic transport and deposition in a beach-dune system (Saunton Sands-Braunton Burrows, southwest England)

Although microplastics (MPs) are ubiquitous contaminants that have been extensively studied in the marine setting, there remain gaps in our understanding of their transport and fate in the coastal zone. In this study, MPs isolated from surface sediments sampled from a large beach-dune complex in southwest England have been quantified and characterised. Concentrations above a detectable size limit of 30 to 50 μm ranged from about 40 to 560 MP kg−1 dry weight but, despite local sources of plastics such as an estuary and seasonal tourism, there were no significant differences in median concentrations between different orthogonal foreshore transects and the dunes or according to zonal location on the beach. The majority of MPs were black and blue fibres of <1 mm in length that were constructed of polymers of density > 1 g cm−3 (e.g., rayon, polyester, acrylic). A significant correlation was found between MP concentration and the proportion of very fine sand (100 to 250 μm) but relationships with other granulometric or compositional markers of sediment (e.g., volume-weighted mean diameter, circularity, calcium content) were not evident. An association of MP concentration with very fine sand was attributed to similar particle depositional characteristics and the entrapment of fibres within small interstitial spaces. Overall, the observations reflect the wavelaid and windlaid deposition of MPs from a diffuse, offshore source, and, despite their role as accumulators of particles from the foreshore, dunes do not appear to act as a landward barrier of MPs.

Characterization of microplastics in digestive tract of commercial fish species from the Oman Sea

Microplastics (MPs) content of the digestive tract of two commercial fish from the northern shores of the Oman Sea were investigated. The MPs were characterized by optical microscopy, fluorescent microscopy, and SEM-EDX for their number, shape, size, and color. Polymer composition was analyzes using micro-Raman spectroscopy (RMS). MPs were recovered in all fish samples (100 %), with an average of 43.16 ± 8.23 items/individual in Otolithes ruber, and 29.9 ± 2.73 items/individual in Acanthopagrus latus. The predominant shape of MPs in both fishes was fiber (46 %) with black, transparent, and white colors. The majority of MPs were <1000 μm (75 %), and half of the MPs were smaller than 300 μm in size. Their synthetic nature was confirmed by Nile Red staining and determination of the elemental composition of selected items. Polypropylene (PP) and polyethylene (PE) were the dominant plastic polymers in the fish digestive tracts. This study reveals abundance distribution of MPs in digestive tract of commercial marine fish. High number of ingested MPs can alarm the accumulation of MPs in the northern of Oman Sea ecosystem with anthropogenic activities and raises issues in public health.

Microplastics in Different Tissues of a Commonly Consumed Fish, Scomberomorus guttatus, from a Large Subtropical Estuary: Accumulation, Characterization, and Contamination Assessment.

Microplastics (MPs) ingestion by fish signifies a worldwide threat to human health but limited research has examined their existence within the consumable portions (muscle) of fish. Thus, this study was undertaken to unveil the prevalence, characterization, and contamination extent of MPs across various body tissues, including the muscle of the king mackerel (S. guttatus) from the lower Meghna estuary in Bangladesh-a pioneering investigation in this region. In our analysis, we identified a total of 487 MPs, with an average abundance of 48.7 ± 20.3 MPs/individual. These MPs were distributed across different tissues, with respective concentrations of 0.84 ± 0.45 items/g in the digestive tract, 2.56 ± 0.73 items/g in the gills, and 0.3 ± 1.72 items/g in the muscle tissue. The observed variations among these tissue types were statistically significant (p < 0.05). Moreover, a significant positive correlation indicated that fish with higher weight had higher MPs in their gills and DT (digestive tract). The majority were <0.5 mm in size (97.74%) and exhibited a fiber-like shape (97.74%), with a notable prevalence of transparent (25.87%) and a pink coloration (27.92%). Remarkably, the majority of MPs were discovered within the size range of <0.5-1 mm (100%), particularly in the muscle tissue, signifying a substantial transfer of MPs into the human diet. Besides, we discovered only three polymer types of microplastics which could be attributed to the extensive use of food packaging, plastic containers, wrapping plastics, residential garbage, and plastic pipes that end up in the aquatic environment via river discharges. The contamination factor (CF) values of fish muscle (5.75) and the digestive tract (5.50) indicated that these fish organs were considerably contaminated (3 < CF < 6) with MPs. The pollution index of MPs (PLI > 1) indicated a high contamination level for MPs pollution of S. guttatus in the lower Meghna River estuary.

Microplastics in commercial fish digestive tracts from freshwater habitats in Northern Thailand

Microplastics (MPs) contamination in fish species was one of the emerging environmental issues as a result of the widespread presence of plastic pollution in the environment. The presence of MPs in Thailand's freshwater was scant, and in contrast to other countries, little was known about the presence of this contaminant in freshwater fish. Hence, the purpose of this study was to examine the abundance, characteristics, and variation of MPs in various Thai commercial freshwater fish species. In order to compare the differences in MP ingestion rates across different feeding zones, 166 fish representing 24 species from various feeding zones were collected. MPs were found in the gastrointestinal tracts (GIT) of all fish samples tested, which was a substantially larger number than previously reported in other locations. Of all the fish species, Anabas testudineus, Labeo rohita, and Oreochromis mossambicus had the highest concentration of MPs (34.90 ± 21.43, 34.50 ± 7.78, 34.10 ± 11.15 items/individuals). Microscopical examinations showed that the majority of MPs were fiber-shaped and blue in color. Fourier transform infrared analysis (FTIR) showed that the polymers found in fish GIT were polyethylene, polypropylene, polyethylene terephthalate, polyvinyl acetate, poly (methyl vinyl ether), poly (methyl vinyl ether), polybutadiene, poly (ethylene-co-propylene), poly (ethylene glycol) tetrahydrofurfuryl ether, poly (methyl phenyl siloxane), poly (styrene-co-divinylbenzene), and polyvinylidene fluoride. The results of this study demonstrate that demersal fish had a higher concentration of MPs than benthopelagic and pelagic fish, indicating that plastic ingestion in fish may be related to the feeding habitat. However, it was not discovered that differences in the fish's body weight and length affected the MPs' ingestion. Our findings will help people in Thailand understand which freshwater fish and fish from which feeding zones are more contaminated with MPs for human consumption.

Tiny and Everywhere: Microplastic Density and Distribution in Sediments along the West Coast of Lombok Island, Indonesia

Microplastics have recently received high global attention, as their widespread presence can potentially cause physical and toxicological risks to organisms. The west coast of Lombok Island in Indonesia has a high potential for microplastic accumulation; even so, its presence in this area was not well studied. Therefore, this study aimed to describe the distribution and density of microplastics within the sediments on the west coast of Lombok. Microplastic sampling had been carried out in the northern, middle, and southern portions of the west coast of Lombok based on distinct geographical and vegetational characteristics. Sediment samples were taken within the HTL (High Tide Line) zone based on the excavation depths categories, i.e. A (0–2cm), B (2–4 cm), C (4–6 cm), D (6–8 cm), and D (8–10 cm). The sediment samples were filtered using an aluminum sieve with a mesh size of 4.75 mm, targeting microplastic pieces below that size. A total of 16,685 microplastic debris were found distributed horizontally and vertically throughout the station. There was a significant difference in the microplastic density distributed between stations [F(10,22) = 6.96, p &lt; 0.001] and between sediment depths [F(10,44) = 9.07,p &lt; 0.001]. The order of average microplastic concentration was southern &gt; northern &gt; middle stations group. The highest microplastic number recorded in SMP11 (southern station, open bay, high anthropogenic activity, with river and primary mangrove vegetation) was as many as 2,361 (density, D = 125,920.00 ± 204.33 items/m3), whereas SMP01 (northern station, open bay, low anthropogenic activity, and with river and secondary mangrove vegetation) had the lowest microplastic number of 678 (D = 36,160.00 ± 72.82 items/m3). In general, the majority of microplastics (45.76%) were distributed on the sediment surface (A–B), where there was a repeating pattern in the difference of microplastic density fluctuations of about 3% at every 4cm of sediment depth (B–C and D–E), which is thought to be driven by daily tidal fluctuation.There was no clear pattern that indicated whether the specific type of shoreline or the presence of rivers and mangroves had an influence on the level of microplastic accumulation. However,the southern stations group had a considerably higher average of microplastic accumulation.We suspect that the geographical position towards the main ocean current contributes greatly to the microplastic accumulation at the site.

Microplastics in water, sediments and macroinvertebrates in a small river of NW Spain

Microplastics (MPs; plastic particles &lt; 5 mm in size) are very common nowadays and ubiquitous in the environment and can cause harm to aquatic organisms. Around 300 million metric tonnes of plastic are manufactured each year and they are regularly mismanaged. Therefore, MPs are frequently found in the environment. Anthropogenic activity in urban areas is considered one of the major sources of MPs. In view of this, we hypothesized, that MPs are present in all areas of rivers, even in riverheads. We analyzed macroinvertebrates in an urban river for MPs and discuss their potential environmental impact. We collected water samples from the centre of the river and filtered the water. Additionally, we collected sediment samples from the the bottom (S1 and S2, both samples collected specifically for sediments analysis) and from the benthic sediment (S3, sample collected for macroinvertebrates identification) from which macroinvertebrates were sampled for MP analysis and for taxonomic identification in order to estimate the water quality of the river, following the protocol for calculating the IBMWP (MAGRAMA, 2011). Sampling took place in the Gafos River (NW Spain) during summer 2020 at three different sampling sites at the head of the river called upstream (G1), in the middle part of the river and upstream of a town (G2) and in the downstream area before the river mouth in the Atlantic Ocean (G3). Different microplastic fibres and particles were found in all water samples (G1, G2 and G3) and in some of the sediment samples. Analysis of the different types of microplastics was carried out by Fourier-transform infrared spectroscopy in attenuated total reflectance mode (ATR- FTIR). The majority of microplastics in water, sediment and biota consisted of polyvinyl chloride (PVC) and polyethylene terephthalate (PET) and the abundances of MPs were very similar. We found more MP particles in biota and water (35 pieces in each compartment) than in sediments (28). Microplastics were found in the cases of Trichoptera families like Lepidostomatidae and Limnephilidae, and inside the body of some Odonata families such as Gomphidae. This confirms the presence of MPs in aquatic organisms and in habitats of an urban river in Spain. Since MPs have been found in freshwater habitats globally, future studies should analyse which macroinvertebrates could be used as MP bioindicators.