Microplastics In Freshwaters Research Articles

Microplastic-contamination in the flesh and gastrointestinal tract of nile tilapia (Oreochromis niloticus) reared in floating net cages at lake Ranu Grati, Pasuruan, East Java, Indonesia

In recent years, microplastics (MPs) have emerged as a prominent environmental problem in waters and environments, including lake waters. Microplastics in freshwater, such as those in floating net cages (FNC), can be consumed by Nile tilapia (Oreochromis niloticus), one of the commercially available cultivated fish in Indonesia. This study aims to determine the prevalence of microplastics and compare their characteristics in the surface water, flesh, and gastrointestinal tract (GIT) of Nile Tilapia (O. niloticus) at Lake Ranu Grati, Pasuruan, East Java, Indonesia. Visual characteristics of MPs were observed using a stereo microscope, and polymers were analysed by ATR-FTIR (Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy). The abundance of MPs from water sample locations in Lake Ranu Grati reached 1116 MPs particles. In the water samples, the inner and outer sides of the FNC are dominated by the MPs with a size range of 251–500 µm and 1001-2000 µm in the milieu of Ranu Grati Lake. The most common MPs' types and colours are fibre and black, dominated by Polyethylene (PE). In 25 O. niloticus samples, 576 particles of MPs were found in the flesh and 724 particles in the gastrointestinal tract (GIT). This study found no significant variation in microplastic abundance between flesh and GIT samples (p>0.05; Mann-Whitney U test). Microplastics in Nile Tilapia flesh samples were dominated by blue fibres with a size range of 101–250 µm, and the polymer found was PA (polyamide). Meanwhile, in the GIT samples, microplastics were dominated by black fibre, with a size range of 251–500 µm, and the polymer found was PA (polyamide).

From Origins to Impacts: A Comprehensive Review of Microplastics in Freshwater Environments

Microplastics are plastic particles of dimensions less than 5mm, increasingly recognized as omnipresent contaminants in freshwater systems. These small particles are sourced from microbeads provided by personal care products, industrial abrasives, and other secondary sources formed by the degradation of larger plastic items. The microplastics are contaminated in freshwater environments through runoff, atmospheric deposition, and the discharge of water treatment processes. The presence of microplastics in freshwater has greater potential to cause harm to aquatic environments and human health. The primary objective of this paper is to identify the microplastic pollution in freshwater resources and classify the sources of this pollution in freshwater resources, including both primary and secondary microplastics, and to evaluate the ecological impact of microplastics and their potential health risks to humans through food chain transfer. This review synthesizes the most recent findings on sources, impacts, and potential mitigation measures of microplastic pollution in freshwater ecosystems to emphasize the attentive work needed urgently in our efforts to conquer the environmental challenge. The mitigation strategies in practice thus focus on policy implementation and correct technology in wastewater treatment, raising public awareness to minimize the use of plastics and encourage good waste management. However, studies with much detail are still required to develop systematic methodologies for microplastic analysis and go far enough to find long-term solutions

The revelry of plastic! Quali-quantitative variation of microplastics in freshwater before and after Carnival in south-eastern Brazil

Context Pollution by synthetic polymers is even more problematic to the environment when this material is fragmented into small portions, forming microplastics (MPs). Aims We analysed the influence of the Brazilian Carnival on the abundance and richness of MPs in the Paraíba do Sul River (PSR). Specific objectives included classifying MPs by shape, colour and polymer, and quantifying and comparing the abundance and richness of surface-water MPs before, during and after Carnival. Methods Samples were taken from the superficial layer of the water column in 2023, by using manta net. Key results In total, 843 MPs were identified in the surface water of PSR. Higher MP concentrations were observed after the Carnival event than in the other two periods. Blue and black fibres were the predominant MPs. Glitter and sequin occurred only during the Carnival and post-Carnival periods. Polyester, polyamide and polyethylene were the most abundant in all the periods. Conclusions Our findings strongly indicated that Carnival represents a potential short-term source of MP introduction into the PSR basin. Implications A significant 170% increase in MP abundance was observed 10 days after the Carnival, which is an event occurring across multiple locations in the PSR basin.

Carrier effects of face mask-derived microplastics on metal ions: Enhanced adsorption by photoaging combined with biofilms, exemplified with Pb(Ⅱ)

Face masks have emerged as a significant source of microplastics (MPs) under the influence of biotic and abiotic interactions. However, the combined effects of abiotic photoaging and biofilm-loading on mask-derived MPs as carriers of metal ions are not clear. We investigated the Pb(Ⅱ) adsorption onto polypropylene (PP) and polyurethane (PU) mask-derived MPs treated by photoaging, biofilm-loading, and both combinations, evaluating the composite risks. PU mask-derived MPs (1.157.47 mg/g) exhibited greater Pb(Ⅱ) adsorption capacity than PP mask-derived MPs (0.842.08 mg/g) because of the presence of intrinsic carbonyl functional groups. Photoaging (30.5%, 88.4%), biofilm-loading (110.7%, 87.1%), and both combinations (146.7%, 547.0%) of PP and PU masks enhanced Pb(Ⅱ) adsorption compared to virgin mask-derived MPs due to the increase of oxygen-containing functional groups. High-throughput sequencing indicated that the structural morphology and chemical composition of masks significantly affected the microbial community. Adsorption mechanisms involved electrostatic force and surface complexation. A combination of photoaging and biofilms increased the ecological risk index of mask-derived MPs in freshwater, showing the risk level to be high (PP mask) and very high (PU mask). This research highlights the crucial role of photoaging combined with biofilms in controlling metal ion adsorption onto mask-derived MPs, thereby increasing the composite risks.

Origin and Effects of Microplastics on Soil Health, Microbial Community and Plants

Microplastics are a growing threat to entire ecosystems, their presence in soil and water ecosystems has received a lot of attention lately. The detection, occurrence, characterization, and toxicology of microplastics in freshwater and marine ecosystems have been the subject of recent research; yet, compared to aquatic environments, our knowledge of the ecological impacts of microplastics in soil ecosystems is relatively restricted. To address the potential ecological and human health risks caused by microplastics in soil, we have compiled literature here that studies the sources, migration of microplastics in soil, negative impacts on soil health and function, trophic transfer in food chains, and the corresponding adverse effects on soil organisms. This paper aims to fill in information gaps, clarify the ecological impacts of microplastic pollution in soil, and suggest future research directions related to microplastic pollution and the ensuing soil ecotoxicity. To lessen the dangers associated with microplastic contamination, this review also focuses on controlling the amount of microplastics in soil and developing management and remediation strategies.

Changes in characteristics and risk of freshwater microplastics under global warming

Microplastics present a significant threat to freshwater ecosystems. However, the impact of global warming on their characteristics and associated risks remains uncertain. This study collected 2793 sample sites from literature and datasets to create a new risk assessment and rank methodology, known as the Multi-characteristics Potential Ecological Risk Index (MPERI), which incorporates various microplastic characteristics, such as concentration, size distribution, color, shape, and polymer diversity. Using regression random forest models (RRF), this study predicted that a 10 °C increase would raise microplastic concentration from 12,465.34 ± 68,603.87 to 13,387.17 ± 60,692.96 particles/m3. The percentage of small-size microplastics initially decreased (from 69.10 % to 68.72 %) and then increased (from 68.72 % to 68.78 %), while the diversity of color, shape, and polymer decreased by 0.29 %, 3.24 %, and 0.17 %, respectively. Furthermore, global warming could increase the rank of microplastic risks from high (405.25 ± 528.9) to dangerous (535.37 ± 582.03) based on the MPERI method. Most countries would experience an increase in risk values, with Indonesia and Vietnam transitioning from low to medium risk, and China and Malaysia transitioning from high to dangerous risk. The feature importance assessment of the RRF model indicated that concentration was the most influential variable in determining the change in risk values. While other microplastic characteristics had a lesser impact compared to concentration, they still influenced the risk ranking. This study highlights the role of global warming in shaping microplastic risks.

Adsorption characteristics of ciprofloxacin hydrochloride on polystyrene microplastics in freshwater.

In order to reveal the adsorption mechanism of microplastics (MPs) on antibiotics, polystyrene (PS) was chosen as a typical microplastic, Fenton and high-temperature aging methods were used to obtain aged MPs particles. The adsorption behavior and mechanism of ciprofloxacin hydrochloride (CIP) on PS before and after aging were studied by batch adsorption experiments, and other influencing environmental conditions were evaluated concurrently. The results showed that the adsorption of CIP on PS was an exothermic reaction, the pseudo-second-order model and Freundlich isothermal models could fit the adsorption of CIP on PS. Aging treatment enhanced the adsorption capacity of PS to CIP, and Fenton aging for 7days had the best effect. The highest adsorption was observed when the solution pH was 6. The adsorption capacity of microplastics gradually decreased with increasing ionic strength and the concentration of fulvic acid, while the aging microplastics changed little with the concentration of fulvic acid. The presence of both Cu (II) and CIP inhibits the adsorption of each other on microplastics. Based on the above findings, the adsorption of CIP on PS is dominated by physical adsorption, and electrostatic interactions and hydrogen bonding interactions are also important mechanisms for the adsorption of CIP on microplastics.

Morphological and Chemical Characteristics of Microplastics in Surface Water of the Vaal River, South Africa

Microplastics research in South Africa has focused on marine and coastal areas, with limited studies reporting microplastics in freshwaters. To address this gap, we conducted this study to investigate the presence, abundance, physical characteristics, and chemical composition of microplastics in the surface water of the Vaal River, one of the most important freshwater systems in South Africa. Twenty-two surface water samples were collected along 60 km of the middle part of the river using a 55 μm plankton net. Samples were treated by acid digestion, and MPs were separated by density separation. Physical identification was performed using a Nikon stereomicroscope, and chemical composition was identified using Raman spectroscopy. MPs were observed in all samples with 0.13 to 2.52 particles/m3 concentrations. Microplastics ranged in size from 0.06 – 4.95 mm, with more than 89% less than 2 mm, and 81% were fragments (39%) and fibers (42%). Microplastics were observed in numerous colours, of which green, black, and blue were the most dominant, representing 22%, 19%, and 18%, respectively. Chemical analysis revealed the polymer types as high-density polyethylene (HDPE), polypropylene (PP), and low-density polyethylene (LDPE). In addition, two colourants, pigment yellow 83 and carbon black, were detected. This study provides new data on microplastic occurrence and characteristics in the Vaal River system and offers a baseline for future monitoring. Our findings confirm that the Vaal River is under a real threat of microplastic contamination, which could impact its role as a significant freshwater system in South Africa.Highlights• Microplastics were prevalent in the surface water of the Vaal River.• Fibrous, small-sized, and coloured microplastics were most abundant.• Polymers were identified as HDPE, LDPE, and PP.

Current patterns and trends of microplastic pollution in the marine environment: A bibliometric analysis.

Microplastics are pervasive in the natural environment and pose a growing concern for global health. Plastic waste in marine environments has emerged as a global issue, threatening not only marine biota but also human health due to its implications for the food chain. This study aims to discern the patterns and trends of research, specifically on Marine Microplastic Pollution (MMP), based on a bibliometric analysis of scientific publications from 2011 to 2022. The methodology utilized in this study comprises three stages: (a) creating a bibliographical dataset from Scopus by Elsevier and the Web of Science Core Collection by Clarivate Analytics, (b) analyzing current research (trends and patterns) using bibliometric analysis through Biblioshiny tool, and (c) examining themes and subthemes in MMP research (wastewater treatment, plastic ingestion, the Mediterranean Sea, microplastics pollution, microplastics in freshwater, microplastic ingestion, plastic pollution, and microplastic pollution in the marine environment). The findings reveal that during the studied period, the number of MMP publications amounted to 1377 articles, with an average citation per publication of 59.23 and a total citation count of 81,553. The most cited article was published in 2011, and since then, the number of publications on this topic has been increasing steadily. The author count stood at 5478, with 22 trending topics identified from the 1377 published titles. Between 2019 and 2022, the countries contributing most to the publication of MMP articles were China, the United States of America (USA), and the United Kingdom (UK). However, a noticeable shift in the origin of author countries was observed in the 2019-2022 timeframe, transitioning from a dominance by the USA and the UK to a predominance by China. In 2019, there was a substantial increase in the volume of publications addressing the topic of microplastics. The results show that the most prevalent themes and subthemes pertained to MMP in the Mediterranean Sea. The journals with the highest number of MMP articles published were the Marine Pollution Bulletin (253 articles) and Science of the Total Environment (190 articles). The analysis concludes that research on MMP remains prominent and appears to be increasing each year.

Assessment of Biofilm Growth on Microplastics in Freshwaters Using a Passive Flow-Through System.

Biofilms that colonize on the surface of microplastics (MPs) in freshwaters may pose a potential health risk. This study examined factors that influence MP-associated biofilm growth, including polymer type, degree of weathering, and source water quality. Weathered MPs produced in-lab were employed in biofilm trials conducted on site using a passive flow-through system with raw water at drinking water treatment facility intakes. Adenosine triphosphate (ATP) was used to quantify biofilm abundance; biofilm composition was assessed via metagenomic sequencing. Biofilm growth was observed on all polymer types examined and most prevalent on polyvinyl chloride (PVC), where ATP levels were 6 to 12 times higher when compared to other polymers. Pathogen-containing species including Salmonella enterica and Escherichia coli were present on all polymers with relative abundance up to 13.7%. S. enterica was selectively enriched on weathered MPs in specific water matrices. These findings support the need to research the potential accumulation of pathogenic organisms on microplastic surfaces.

Microplastic-specific biofilm growth determines the vertical transport of plastics in freshwater

Understanding the sinking behavior of microplastics in freshwater is essential for assessing their environmental impact, guiding research efforts, and formulating effective policies to mitigate plastic pollution. Sinking behavior is a complex process driven by plastic density, environmental factors and particle characteristics. Moreover, the growth of biological entities on the plastic surface can affect the total density of the microplastics and thus influence the sinking behavior. Yet, our understanding of these processes in freshwater is still limited. Our research thus focused on studying biofilm growth on microplastics in freshwater. Therefore, we evaluated biofilm growth on five different polymer types (both microplastic particles and plates) which were incubated in freshwater for 63 days in a controlled laboratory setting. Biofilm growth (mass-based) was used to compare biofilm growth between polymer types, surface roughness and study the changes over time. Understanding the temporal aspect of biofilm growth enabled us to refine calculations on the predicted effect of biofilm growth on the settling behavior in freshwater. The results showed that biofilm formation is polymer-specific but also affected by surface roughness, with a rougher surface promoting biofilm growth. For PET and PS, biofilm tended to grow exponentially during 63 days of incubation. Based on our calculations, biofilm growth did affect the sinking behavior differently based on the polymer type, size and density. Rivers can function as sinks for some particles such as large PET particles. Nevertheless, for others, the likelihood of settling within river systems appears limited, thereby increasing the probability of their transit to estuarine or oceanic environments under hydrometeorological influences. While the complexity of biofilm dynamics on plastic surfaces is not fully understood, our findings help to elucidate the effect of biofilms on the vertical behavior of microplastics in freshwater systems hereby offering knowledge to interpret observed patterns in environmental plastic concentrations.

Column-based removal of high concentration microplastics in synthetic wastewater using granular activated carbon

ABSTRACTMicroplastic (MP) is an emerging contaminant of concern due to its abundance in the environment. Wastewater treatment plant (WWTP) can be considered as one of the main sources of microplastics in freshwater due to its inefficiency in the complete removal of small MPs. In this study, a column-based MP removal which could serve as a tertiary treatment in WWTPs is evaluated using granular activated carbon (GAC) as adsorbent/filter media, eliminating clogging problems commonly caused by powder form activated carbon (PAC). The GAC is characterized via N2 adsorption–desorption isotherm, field emission scanning electron microscopy, and contact angle measurement to determine the influence of its properties on MP removal efficiency. MPs (40–48 μm) removal up to 95.5% was observed with 0.2 g/L MP, which is the lowest concentration tested in this work, but still higher than commonly used MP concentration in other studies. The performance is reduced with further increase in MP concentration (up to 1.0 g/L), but increasing the GAC bed length from 7.5 to 17.5 cm could lead to better removal efficiencies. MP particles are immobilized by the GAC predominantly by filtration process by being entangled with small GAC particles/chips or stuck between the GAC particles. MPs are insignificantly removed by adsorption process through entrapment in GAC porous structure or attachment onto the GAC surface.

Meta-analysis of the hazards of microplastics in freshwaters using species sensitivity distributions

The environmental hazards of microplastics have raised concerns about their potential ecological risks. However, our understanding of the true risks may be limited because most laboratory studies used pristine microplastics. Here, we analyzed the available literature about ecotoxicological effects of microplastics, including weathered microplastics in particular, on freshwater biota and performed probabilistic species sensitivity distributions. The predicted no-effect concentrations for pristine microplastics were lower than those for weathered microplastics, both in mass concentration (6.1 and 4.8 × 102 μg/L) and number concentration (2.6 × 104 and 2.0 × 106 part/m3). In addition, the toxicological studies on microplastics contains often inconsistent and inconclusive information due to the complexity of the microplastics and the employed exposure conditions. The available data for Daphnia magna and Danio rerio was analyzed in detail to understand the effects of microplastic size, shape and polymer type on their ecotoxicity. Microplastic size was the biggest driving factor, followed by shape and polymer type. There was a tendency for increasing toxicity with smaller size, however, a high variability of effect data was observed for small microplastics. This study provided further insights into the effect thresholds for ecological risk assessment of microplastics and the effects of microplastic characteristics on toxicity.

Adsorption/desorption of mercury (II) by artificially weathered microplastics: Kinetics, isotherms, and influencing factors

While both mercury (Hg) and microplastics (MPs) are well-studied global pollutants, comparatively little is known about the interactions between them and the mobilization of Hg from MPs into organisms. We examined the affinity of Hg(II) to artificially weathered MPs, including polyamide (w-PA), polyethylene (w-PE), polyethylene terephthalate (w-PET), polyester fibers (w-PEST), polyvinyl chloride (w-PVC), and polylactic acid (w-PLA), along with crumb rubber (CR) and PE collected from a wastewater treatment plant (WWTP-PE). WWTP-PE, CR, and w-PEST had particularly high Hg(II) affinities, which can be attributed to electrostatic interaction and pore filling. The adsorption followed a pseudo-second-order kinetic process and fitted the Freundlich model, suggesting multi-step (mass transfer and intraparticle diffusion) and heterogeneous adsorptions. Hydrochemical conditions (pH, dissolved organic matter (DOM), salinity and co-existent metal ions) all impacted Hg-MP behavior. Changes in Hg speciation and MP surface properties contributed to the different Hg(II) adsorption capacities for the MPs. Weathering of MPs generally increased the adsorption of Hg(II) onto MPs, but CR, PET and PEST did not follow this trend. Less than 3% of adsorbed Hg(II) was mobilized from the MPs in freshwater, but that increased up to 73% under simulated avian digestive conditions, suggesting increased bioavailability of Hg(II) from ingested MPs. Overall, weathered MPs adsorb and retain Hg(II) under environmentally relevant conditions but desorb much of it in simulated avian digestion fluid, suggesting that birds that ingest MPs may have increased Hg(II) exposure.

Adsorption of Per- and Polyfluoroalkyl Substances (PFAS) and Microcystins by Virgin and Weathered Microplastics in Freshwater Matrices.

Microplastics and per- and polyfluoroalkyl substances (PFAS) both represent persistent groups of environmental contaminants that have been associated with human health risks. Microcystin toxins are produced and stored in the cells of cyanobacteria and may be released into sources of drinking water. Recent concerns have emerged regarding the ability of microplastics to adsorb a range of organic contaminants, including PFAS and microcystins. This study examined the adsorption of two long-chain and two short-chain PFAS, as well as two common microcystins, by both virgin and weathered microplastics in freshwater. Natural weathering of microplastic surfaces may decrease adsorption by introducing hydrophilic oxygen-containing functional groups. Up to 50% adsorption of perfluorooctanesulfonic acid (PFOS) was observed for virgin PVC compared to 38% for weathered PVC. In contrast, adsorption capacities for microcystins by virgin LDPE were approximately 5.0 µg/g whereas no adsorption was observed following weathering. These results suggest that adsorption is driven by specific polymer types and dominated by hydrophobic interactions. This is the first known study to quantify PFAS and microcystins adsorption when considering environmentally relevant concentrations as well as weathered microplastics.

Evaluation of vertical distribution characteristics of microplastics under 20μm in lake and river waters in South Korea.

Following the alarming reports of microplastic pollution in the marine environment, increased attention has been given to microplastics in other environmental media. Despite the attention, there is limited research available on the depth-distribution of microplastics in freshwater. Specifically, in the case of water sources used for drinking or tap, the height of intake facilities varies, and it is highly likely that there is a correlation between the vertical distribution of microplastics and these water intake structures. Further, because the size of microplastics varies widely in the environment, the commonly used sampling devices are not suitable for selectively extracting microplastics without causing cross-contamination. Thus, we developed a suitable device for microplastics of size 5-20µm and studied microplastic distribution in freshwater at various depths by considering various types of microplastics and aqueous systems. Lake and river, two major water sources, were selected for the study of microplastics distribution in water system. The microplastic distribution characteristics in both water systems showed that polypropylene and polyethylene were the most abundant across all depths because of their production volume. Plastic types with higher density were found only at the lower layers, and polystyrene was found in the upper layers because of the environmental effects on its buoyancy caused pore diameter and surface area. The lake and river had higher microplastic distribution in the lower layer and upper layer, respectively. This was because the flow rate in river was higher than that of lake. The higher flow rate reduced the settling velocity in river. Thus, hydrodynamic stability influences the vertical distribution and concentrations of microplastics in the water systems. These results are expected to be used for understanding the behavioral characteristics of microplastics in water systems and to manage water sources.

Modeling the effect of fish migration on the horizontal distribution of microplastics in freshwater and ecological risks in the food web: Influence of habitat

Microplastics (MPs < 5 mm) pollution is a widespread phenomenon in freshwater ecosystems. While the role of physiochemical factors in the migration and distribution of MPs is understood, the impact of biological migration remains less clear. The influence of nekton migration determined by habitat suitability on the distribution of MPs and the consequent ecological risks to the regional food web is investigated in the freshwater environment by using Baiyangdian Lake (China) as a case study. The key findings reveal that fish migration significantly alters the horizontal distribution of MPs in the water environment, with a higher degree of fish aggregation in high suitability habitats leading to an increased presence of MPs due to their ingestion and excretion behaviors. In both high and low suitability habitats, MPs are found to bioconcentrate in fish, suggesting a significant risk to aquatic ecosystems. Despite the lack of evidence supporting MPs biomagnification, the results indicate that MPs are more likely to be biomagnified within the food web of high suitability habitats due to the enhanced foraging capabilities of aquatic organisms. These findings highlight the critical need to consider biological factors, such as nekton migration, in understanding and addressing MPs pollution in freshwater ecosystems.

Microplastic abundance, distribution, and diversity in water and sediments along a subtropical river system.

Microplastic pollution in aquatic environments has been a ubiquitous concern in recent years, owing to their rapid production combined with poor waste management practices. However, information on freshwater microplastics in the Global South is still scarce, despite growing research on freshwater microplastics in recent years, particularly within the Global North. To help address this knowledge gap, we studied water and sediment microplastic dynamics along a subtropical river system, i.e. Crocodile River around the Nelspruit City area (South Africa), across three different seasons (i.e. cool-dry, hot-dry, hot-wet) using a combination of diversity indices and multivariate analyses. Microplastics were more abundant during the cool-dry season in the surface water samples (mean 1058 particles m-3) and high during the hot-dry season (mean 568 particles kg-1 dwt) in the sediment samples. The hot-wet season had a low particle density in both surface water (mean 625 particles m-3) and sediments (mean 86 particles kg-1 dwt) samples. Microplastic shapes were dominated by fibres and fragments, with the colour scheme dominated by transparent, blue, and black. The abundance of microplastics was positively correlated with pH and resistivity, and negatively with river flow. Wastewater was attributed as a primary source of microplastics, particularly because of the observed dominant fibre microplastics, usually released during laundry. Our results suggest that Crocodile River and its tributaries are temporary sinks of microplastics during periods of low rainfall. Implications of this pollution are far-reaching, including effects on residents who are dependent on the Crocodile River as a source of drinking water and aquatic biota which may be exposed to these pollutants.

Microplastics in Tai lake food web: Trophic transfer and human health risk assessment

Although microplastics (MPs) in marine organisms have been widely studied, the toxicity of MPs in freshwaters and human health is still a global challenge. To fill this gap, we implemented an Ecopath and food web accumulation model to simulate the Tai Lake ecosystem, a region dependent on the tourism and seafood industries. Our results suggested the accumulation of MPs throughout the food web and ultimately reach organisms at high trophic levels, including human-being, who consume MPs through seafood. The adults were prone to consume more MPs than adolescents and children. Unlike clams, fish biota magnification factors indicated that MPs accumulation between specific predator-prey interactions is not expected. The abundance of MPs within clams reveals a potential risk of MPs entering the food web. To better understand the MPs transfer, we recommend paying greater attention to species-specific mechanisms and the resources they rely on.

Occurrence of Microplastics in Kemena River and Niah River of Sarawak, Malaysia

Microplastics in freshwater have been identified as a significant contributor to plastic pollution in marine environments. However, the effect of urbanization on the quantity and spatial dispersion of microplastics in freshwater ecosystems of Sarawak and Malaysia remains unclear. The primary objectives of this study are to investigate the quantity and distribution of microplastics in water and riverbank sediments, as well as to analyze the properties of microplastic particles in the Kemena and Niah rivers. The selection of these rivers was based on the presence of commercial, residential, and industrial areas along their lengths. A total of 24 water and soil sediment samples were collected from three different sites along the Kemena and Niah rivers. The concentration of microplastics in water samples ranged from 60 to 128 items per liter, while sediment samples ranged from 46 to 76 items per liter. The sediment samples also contained microplastics ranging from 21 to 40 and 45 to 125 items per kilogram. Microplastics were observed in various forms, including fibers, films, foam, and fragments, in both water and soil sediment samples. The majority of microplastics were between 0.1 and 1 mm in size, with blue being the most common color observed in river water and transparent in sediment samples. The ATR-FTIR spectrum analysis indicated the presence of four distinct polymers: polyethylene (PE), polystyrene (PS), polycarbonate (PC), and polyethylene terephthalate (PET). This study provides valuable information on the abundance, distribution, chemical composition, and physical properties of microplastics in the Kemena and Niah rivers.