Emergence of microplastics in the aquatic ecosystem and their potential effects on health risks: The insights into Vietnam

Microplastic contamination in water, fish, and shrimp collected from the Nile River in Upper Egypt poses ecological and human health hazards

Microplastic (MP) pollution is a growing environmental concern, particularly in freshwater ecosystems. This study investigates MP contamination in the Nile River in Upper Egypt by analyzing water samples and two aquatic species, Gambusia sp. and Caridina nilotica. Samples were collected from three sites with varying anthropogenic influences, and MPs were characterized based on shape, size, color, and polymer composition using FTIR spectroscopy. Results revealed a high MP concentration in water (4.5 ± 2.1 particles/L), with significant spatial variation. The highest contamination was recorded in urban-influenced areas, highlighting domestic and industrial waste as key pollution sources. Fibers (75 %) were the most abundant MP type, followed by fragments (19 %), with polyethylene terephthalate (PET) being the dominant polymer (79 %). Both Gambusia sp. and C. nilotica exhibited MP ingestion, with higher loads detected in Gambusia sp. Feeding preferences were observed, with Gambusia sp. favoring fragments and C. nilotica preferring fibers. Risk assessments classified MP pollution as extremely high, with severe ecological risks (RI > 1200). Initial estimates of human exposure through water consumption suggested that adults may ingest 5,840-12,373 MP/kg body weight annually, while children may ingest 3,103-6,187 MP/kg body weight for the best- and worst-case exposure scenarios. These findings highlight significant MP contamination in the Nile, raising concerns about ecosystem and human health risks. Urgent mitigation strategies, including improved waste management and pollution control, are necessary to reduce MP exposure and protect aquatic biodiversity.

Risk assessment and contaminant characterization of PCBs, PAHs, and heavy metals in Pichavaram mangrove sediments, Tamil Nadu, India

The coastal region of Pichavaram, Tamil Nadu, India, is a critical ecological zone that supports diverse marine life and local livelihoods; however, it faces significant environmental challenges due to contamination from persistent toxic substances (PTSs) and heavy metals, which pose serious ecological and human health risks. In the present study, sediment samples collected from the mangrove environment were tested for polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and heavy metals. The results revealed elevated concentrations of ∑PCBs (6-124 ng/g) and ∑PAHs (3.19-37.8 ng/g), alongside heavy metals such as Pb (11-26 μg/g), Cd (0.3-0.87 μg/g), Cu (below detectable levels, bdl)-31 μg/g), Ni (bdl-119 μg/g), and Zn (27-109 μg/g), indicating significant environmental contamination. The total PCB concentrations surpassed the guideline values, indicating potential risks to aquatic life. Elevated naphthalene levels in Kodipallam suggest petrogenic inputs from oil spills and urban runoff. Carcinogenic PAHs, including benzo[a]pyrene, are found at high levels in industrial zones such as Killai, and pose moderate ecological risks. Heavy metals such as As (68-140 μg/g), Cr (25-120 μg/g), and Mn (94-471 μg/g) often exceeded the threshold effect levels (TEL) and probable effect levels (PEL), indicating significant ecological risks and potential human health impacts. Coastal sediment contamination, driven by discharges from chemical industries, oil refineries, metal manufacturing, and agricultural runoff, poses long-term risks to marine life and human health through the bioaccumulation of persistent pollutants in the food chain. This study provides crucial baseline data for future monitoring and emphasizes the need for stricter regulatory measures and pollution management strategies. Recommendations include regular sediment quality monitoring, public awareness campaigns on pollution sources, and sustainable practices to mitigate risks, thereby protecting the coastal environment and local communities.

Study on the toxic effect of seawater-aged microplastics on Philippine curtain clams

This study delved into the impact of aging on the properties of five common microplastic types, including polymethylmethacrylate (PMMA), polystyrene (PS), polyvinyl chloride (PVC), polyethylene (PE), and polypropylene (PP). The aging process significantly altered the particle size distribution: PS, PP, and PMMA underwent a contraction, with average sizes decreasing by 6.8%, 3.2%, and 1.7%, respectively, whereas PE and PVC experienced an expansion, with increases of 3.1% and 1.7%. Notably, aging generally increased the specific surface area of all microplastics by more than 20%, a change that could influence their environmental interactions. Scanning electron microscopy revealed marked surface cracks and depressions in aged PE and PVC, in contrast to minor surface alterations in PS and PMMA. Fourier transform infrared spectroscopy further indicated modifications in the characteristic peaks of aged PMMA, PP, and PE microplastics. Exposure experiments demonstrates that increasing microplastic concentrations from 100 mg/L to 5000 mg/L accelerated mortality rates in clams, with juveniles exhibiting slower mortality onset compared to adults. Prolonged exposure led to rising mortality rates across all groups, suggesting a cumulative toxic effect from long-term microplastic exposure. These findings underscore the environmental ecological risks associated with the altered physicochemical properties of aged microplastics, particularly for the Philippine clam. This study provides an essential insight for advancing our understanding of microplastic behavior and their ecological impacts, highlighting the need for further research to mitigate these environmental threats.

Plastic wastes for carbon-based materials: Investigations on recent applications towards environmentally sustainable, carbon dioxide capture and green energy

The rapid growth in plastic production, coupled with inadequate waste management, has led to a significant accumulation of plastic waste in different environments. This raises substantial concerns about long-term ecological impacts, including bioaccumulation in organisms and potential risks to human health. This review focuses on plastic waste-derived carbon materials (PWCMs) and their role in promoting sustainable, eco-friendly energy solutions. The novelty of the study examines the current progress in converting plastic waste into carbon-based materials, with a particular emphasis on recent applications in environmentally sustainable practices, carbon dioxide capture, and green energy solutions. The growing interest in carbon-based materials is due to their unique characteristics, including high specific surface area, porosity, electronic conductivity, stable structure, and versatile surface chemistry. The utilization of PWCMs and their composites has shown promise in absorbing a wide range of contaminants. For organic pollutants, this includes dyes such as methylene blue and pharmaceuticals like antibiotics, polycyclic aromatic hydrocarbons (PAHs), and other endocrine-disrupting chemicals (EDCs). For inorganic contaminants, PWCMs effectively target heavy metals, i.e., cadmium, lead, mercury, and arsenic, as well as anions like nitrate and phosphate. Converting waste plastics into carbonaceous adsorbents holds excellent potential for removing up to 99% of toxic metal elements from wastewater. Furthermore, carbon capture through PWCMs provides an environmentally friendly and practical approach to closing the carbon loop, advancing carbon neutrality, and fostering a more sustainable future. Repurposing waste plastic for hydrogen production has significant potential to contribute to decarbonization efforts and accelerate achieving sustainable development goals (SDGs). The findings also offer valuable insights into the advanced uses of PWCMs, encouraging future efforts in upcycling plastic waste for innovative and sustainable solutions. Yet, a comprehensive evaluation of PWCM applications and their limitations is needed to guide future research toward optimizing their synthesis for economic and environmental sustainability.

Spatial mapping and risk assessment of microplastic contamination in drinking water catchments from north of the Persian Gulf

Microplastics (MPs) are emerging contaminants in drinking water that raise global concerns due to their health risks and long-term environmental persistence. These tiny plastic particles can accumulate within human bodies and ecosystems, making it essential to understand their presence and behavior in water sources, especially in drinking water. In Khuzestan Province, which is of strategic importance in the Gulf region. This study assesses the concentration and types of MPs entering and leaving these 11 treatment plants. In untreated water, particle size analysis revealed that 50% of MPs were measured under 101 µm, with fibers being the most common type (47%), followed by fragments and pellets. Although treatment processes reduced overall MP concentrations, fibers remained the dominant residual type, making up 71% of the MPs in treated water. The main polymers identified were polyethylene (PE) and polypropylene (PP), with PE accounting for up to 75% of MPs in some areas. In terms of color, black/gray MPs were most prevalent (45%), followed by blue, red/pink, yellow/orange, and white/clear particles. While most treatment plants achieved significant reductions in MP levels, some were less effective, likely due to differences in treatment technologies. Notably, the S10 plant in Bandar Mahshahr had especially high inlet MP levels, possibly due to the region's high industrial and human activities. Estimated daily intake (EDI) for adults was approximately 0.00482 MPs per kg of body weight per day, with children having a higher intake of around 0.01866 MPs per kg per day. These findings highlight the need to enhance treatment technologies, control upstream MP sources, and establish routine monitoring to protect water quality in Khuzestan and the wider Gulf region.

A Review on Flame Retardants in Soils: Occurrence, Environmental Impact, Health Risks, Remediation Strategies, and Future Perspectives

As novel pollutants, flame retardants (FRs) are prone to accumulating in soil and might increase human health risks. It is advisable to emphasize the biomagnification of FRs within the terrestrial food chain, particularly concerning mammals occupying higher trophic levels. Exposure to soil particles laden with FRs may result in numerous health complications. These findings offer significant insights into FR pollutant profiles, tracing origins and recognizing health risks associated with soil samples. Reports have revealed that exposure to FRs can pose serious health risks, including neurodevelopmental impairments, endocrine system disruption, and an increased likelihood of cancer. Nanomaterials, with their high surface area and flexible properties, possess the ability to utilize light for catalytic reactions. This unique capability allows them to effectively degrade harmful contaminants, such as FRs, in soil. Additionally, biological degradation, driven by microorganisms, offers a sustainable method for breaking down these pollutants, providing an eco-friendly approach to soil remediation. These approaches, combined with optimum remediation strategies, hold great potential for effectively addressing soil contamination in the future. Further research should prioritize several key areas, including ecological behavior, contaminant monitoring, biological metabolomics, toxicity evaluation, and ecological impact assessment.

Screening method for differentiation of plastic and non-plastic microparticles contaminating store-bought rice

This article presents a simple and low-cost screening method based on optical microscopy and FT-IR spectroscopy for assessing microparticles found in rice. Five brands of rice packed in paper and foil bags from both the European Union (EU) and non-EU region were tested. Microparticles of various shapes have been found in the rice regardless of the packaging type and origin of the rice. The content of microparticles varies depending on the sample, from 2 to even 12 items per 1 g of rice. Overall, the abundance of microparticles is higher in the case of rice packed in foil bags. Not all identified microparticles are microplastics, but those that are microplastics cannot be directly linked to the composition of the rice package. For a cursory analysis aimed at distinguishing the infrared spectra of non-plastic microparticles (i.e. rice, paper or cellulose) from microplastics, it is sufficient only to analyse the absorption bands above 2800 cm-1.

Investigating macro marine litter and beach cleanliness along Southern Vietnam beaches

Plastic contamination is a major issue for marine ecosystems, with macro-litter posing a growing threat globally. This study assesses macro-marine litter on Vung Tau beaches, Southern Vietnam, providing baseline data for marine litter pollution and identifying critical action plans for plastic control. Survey results showed litter density ranging from 0.1768 to 0.4464 items m-2 across twelve sites. Using the Clean Coast Index (CCI), 16.7 % of beaches were rated as "Clean" and 83.3 % as "Moderate," while the Plastic Abundance Index (PAI) revealed 91.7 % of sites had "Moderate" plastic levels. Human activities, such as tourism and insufficient waste management, were key contributors. Addressing this issue requires raising awareness, promoting behavioural change and tourist perceptions, and enhancing waste management efforts. Prioritizing marine protection programs is crucial for effectively eliminating marine litter and plastic waste.

Modeling the spatiotemporal distribution, bioaccumulation, and ecological risk assessment of microplastics in aquatic ecosystems: A review

Microplastic (MP) pollution poses a significant threat to aquatic ecosystems. Numerical modeling has emerged as an effective tool for predicting the distribution, accumulation, and risk assessment of MPs in aquatic ecosystems. However, published work has not systematically assessed the strengths and weaknesses of various modeling approaches. Therefore, we conducted a thorough review of the main modeling approaches for MPs over the past six years. We classified the approaches into three categories as: spatial and temporal distribution, bioaccumulation, and systematic ecological risk assessment. The review analyzed application scenarios, modeling methods, and the advantages and disadvantages of models. The results indicate that the accurate simulation of MPs spatial and temporal distribution requires reasonable parameterization and comprehensive transport considerations. Meanwhile, it is important to focus on coupling process models with other types of models. To enhance risk assessment models, expanding the relevant evaluation indicators is essential.

Investigation of microplastic pollution index in the urban surface water: A case study in west Godavari district, Andhra Pradesh, India

Microplastics (MPs) are a growing environmental issue because of their widespread prevalence and their long-term effects on ecosystems and human health. Global studies have identified MPs in various aquatic environments, such as lake, rivers, estuaries, wastewater, and oceans. Although most MPs originate from urban surface water sources, the specific intensity, characteristics, and associated risk assessments remain unclear. This study focuses on west Godavari region of India, specifically analyzing MPs in surface water samples Godavari River and two water treatment plants (WTPs). A total of 330 MPs found in the surface water and 121 MPs in theWTP. In surface water, MPs were predominantly blue and transparent fibers, with the majority measuring less than 500 μm in size. Conversely, at the WTP, larger MPs, primarily in blue fiber form and exceeding 3000 μm, were observed. Additionally, μ-Raman spectroscopy analysis identified the presence of various polymers, including PP, PVC, PC, Nylon, and PET, among others. The risks associated with MPs, including their concentration and chemical composition, were assessed across all sample types using various indices such as Contamination Factor (CFi), Pollution Load Index (PLI), Polymer Risk Index (H), Potential Ecological Risk Index (RI), and Estimated Intake (EI) (daily, annually, and lifetime). The risk assessment revealed that the type of polymer poses a greater risk of MP pollution than the concentrations of MPs themselves. These findings provide critical insights into MP contamination patterns and risks, emphasizing the need for targeted mitigation strategies in this region.

Toxicological effects and potential reproductive risk of microplastic-induced molecular changes in protamine-like proteins and their DNA binding

Today, plastic pollution is a widespread problem in all ecosystems and has a particularly severe impact on marine ecosystems and external fertilisers such as the mussel Mytilus galloprovincialis. The present study aims to assess the toxicological reproductive health effects in this organism following exposure to two concentrations of polystyrene microplastics (PS-MPs) (0.5 and 1 μg/L), representative of conditions in the Mediterranean Sea. After exposure, the electrophoretic pattern of protamine-like (PL) proteins, the major basic protein component of Mytilus galloprovincialis sperm chromatin, was analysed. Compared to the unexposed condition, differences were observed by SDS-PAGE and an increased ability of PL to bind and protect DNA from oxidative damage was then measured, particularly for PL from mussels exposed to 1 μg/L PS-MPs. At this dose of PS-MPs, a reduced release of all PLs from the sperm nuclei was also observed, whereas the digestion by micrococcal nuclease did not show any significant differences between the exposed and the unexposed conditions. Finally, the possibility of poly(ADP)-ribosylation of the PLs was investigated. PL-II showed an increase in poly(ADP)-ribosylation after PS-MPs exposure, which may account for the difference in the ability of the PLs to bind DNA. In conclusion, while all the results might suggest a molecular mechanism of gametic plasticity occurring upon exposure of mussels to PS-MPs 1 μg/L, they also indicate that this dose of exposure could be extremely detrimental to the reproductive health of Mytilus galloprovincialis because it could prevent the release of basic nuclear proteins from the sperm DNA at fertilisation.

Amino modifications exacerbate the developmental abnormalities of polystyrene microplastics via mitochondria-mediated apoptosis pathway in zebrafish larvae

Microplastics (MPs) are ubiquitous in the environment and have been identified as a potential threat to ecosystems. However, the mechanisms of toxicity of modified MPs remain unknown. This study investigated the developmental toxicity of amino-modified polystyrene microplastics (PS-NH2) with environmentally relevant concentrations ranging from 0.1 to 100 μg/L in the early developmental stages of zebrafish. Adding amino functional groups resulted in significant alterations in the surface morphology and zeta potential of traditional polystyrene microplastics (PS-MPs). Zebrafish larvae exposed to PS-NH2 exhibited increased developmental toxicity compared to PS-MPs, as indicated by reduced body length, heart rate, and spontaneous movement. The expression of cat1, sod1, gstr1, nrf2a, nrf2b, and HO-1, as well as alterations in ROS, SOD, CAT, and MDA levels, all demonstrated oxidative damage caused by PS-NH2 exposure. Mitochondrial dysfunction was also induced, as evidenced by changes in the expression of cox4i1, ndufs1, and uqcrc1, as well as changes in the levels of ATP, cytochrome c, NAD, and NADH. Furthermore, PS-NH2 exposure disrupted apoptosis regulation, increasing apoptotic cells and caspase activity, along with changes in caspase-3 and bcl-2 expression. Molecular docking showed that PS-NH2 interacts with bcl-2 with high binding energy. This study contributes to understanding the toxic effects and mechanisms of charge-modified MPs in zebrafish.

Cigarette butts in Vietnam's marine environments: From pollution to solutions and prospects

Cigarette butts contain over 4000 toxic chemicals, including nicotine, tar, and heavy metals. More than 90 % of cigarettes sold today feature single-use plastic filters composed of cellulose acetate fibers and various additives. Cigarette butts are hazardous waste that pose significant risks to ecosystems and human health. Littered cigarette butts can act as an essential vehicle for toxic chemicals in the water environment. Cigarette butts contribute to gradual environmental degradation by releasing heavy metals such as lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu), vanadium (V), nickel (Ni), and arsenic (As). Recent reports highlight the alarming increase in cigarette butt pollution on beaches, emphasizing the significance of commercial cigarette filters as single-use plastics and the primary contributors to this environmental threat. Given their potential toxicity, the research community has increasingly focused on understanding the profound impact of cigarette butt pollution on freshwater bodies, marine ecosystems, and terrestrial environments. However, there remains a considerable gap in knowledge regarding the extent of cigarette butt pollution, especially on Vietnam's beaches. While cigarette butts are a pervasive form of litter globally, little is known about their environmental effects, accumulation patterns, potential toxicity, and impacts on the coastline of Vietnam. This underscores the need for an in-depth investigation into this issue, expressing disappointment over the limited research conducted in coastal areas thus far. This article advocates for active participation from the scientific community to bridge this gap, asserting that collaborative research efforts will bring attention to and address the critical issue of cigarette butt pollution in Vietnam's regions and potential harm to natural ecosystems. Furthermore, enhancing research efforts to understand and mitigate cigarette butt pollution on Vietnam's beaches is crucial for achieving sustainable development goals (SDGs).

Risk assessments of microplastic exposure in bivalves living in the coral reefs of Vietnam

This study aimed to assess the presence of microplastics in bottom sediment and bivalve species, including Pinna bicolor, Atrina vexillum, Saccostrea sp., and Pinctada margaritifera, living in coral reefs on Vietnam's Southern coastal. The average microplastic abundance were 0.45 ± 0.13 items/g of wet soft tissue weight or 5.60 ± 1.49 items/individual in bivalve samples and 294 ± 43 items/kg dry weight of sediment samples. The fragment shape, size smaller than 100 μm, and polyethylene, polyamide, cellophane and polyethylene terephthalate were identified as the predominant constituents of the microplastics. The pollution load and potential ecological risk index of microplastics were at a minor level, whereas the polymer hazard index was at a high level. Overall, this study provides a basis for assessing the risks posed by microplastics in the marine ecosystems of Vietnam.

Seasonal change in fate and transport of plastics from Red River to the coast of Vietnam

A Lagrangian-particle tracking model, Delft3D-PART, combined with hydrodynamics models are used to investigate the fate and transport of buoyant plastics from Ba Lat river mouth in Red River Delta, northern Vietnam. It was found that during the dry season (Dec-Feb), 23 % (26.43 ton) of the plastics reached the shoreline while 76.1 % (68.3 ton) moved towards the coast further south of Red River Delta. During the wet season (Jun-Aug), 42 % (56.3 ton) were transported offshore away from the coast and 20 % (26.43 ton) distributed along the shore. The two bays adjacent to the river mouth are major hotspots with the intensity skewed towards the upwind side relative to the seasonal monsoon. This phenomenon is exacerbated by storm events which reverse the typical transport and lead to formation of hotspots at the upwind side of the plastic source. Guidance of model results for targeted cleanup operations is discussed.

Micro/nano plastics in the urinary system: Pathways, mechanisms, and health risks

Micro/Nano plastics (MNPs) pollutants are widespread in the environment, raising significant concerns about their biosafety. Emerging studies indicate that the urinary system is a primary accumulation site for MNPs, leading to severe tissue and functional damage. This review aims to summarize recent research on the potential hazards that MNPs may pose to the urinary system, highlighting the mechanisms of toxicity and the current state of knowledge. Studies have shown that MNPs enter the human body through drinking water, the food chain, inhalation, and skin contact. They may penetrate the bloodstream via the digestive, respiratory, and skin systems, subsequently dispersing to various organs, including the urinary system. The potential accumulation of MNPs in the urinary system might induce cellular oxidative stress, inflammation, apoptosis, autophagy, the "intestine-kidney axis", and other possible toxic mechanisms. These processes could disrupt kidney metabolic functions and promote tissue fibrosis, thereby potentially increasing the risk of urinary system diseases. Despite ongoing research, the understanding of MNPs' impact on the urinary system remains limited. Therefore, this review provides a comprehensive overview of MNPs' potential toxicity mechanisms in the urinary system, highlights key challenges, and outlines future research directions. It offers a theoretical basis for the development of effective protective measures and policies.

Prevention policies for the marine ecological environment in the South China Sea as a consequence of excessive plastic compound use in Vietnam

Vietnam suffers from a distressing predicament: It ranks among the most heavily contaminated nations on earth. Its coastal and marine domains are plagued by an excess of plastic waste. Vietnam has consistently discharged a substantial amount of waste into the oceans, ranging from 0.28 to 0.73 million metric tons annually. Numerous areas have emerged as focal points of plastic pollution throughout its extensive seashore and marine areas. The escalating presence of marine litter poses an increasingly grave threat to the intricate equilibrium of Vietnam's marine ecosystems. This comprehensive policy study reveals that the mounting problem of ocean plastic pollution, characterized by the abundance of floating plastic debris, imperils both plant and animal life, placing various marine species such as seabirds, fish, turtles, and cetaceans at risk. The consumption of minuscule plastic particles and the harmful impact of chemical pollutants from plastic waste in the ocean not only endangers the vitality of marine life but also poses a substantial hazard to human well-being because plastic waste infiltrates the food chain. This research reveals that, despite the existence of numerous laws and policies-including the Law on Environmental Protection 2020, the Marine Plastic Waste Management Initiative for the Fisheries Sector 2020-2030, and the National Action Plan for Management of Marine Plastic Litter-a significant amount of plastic waste is infiltrating the river network and eventually infiltrating oceans as a result of improper monitoring and ineffective enforcement of these legislations. Relying primarily on existing data released by the government and other sources and a wide range of gray literature retrieved from reputable databases, this study aims to evaluate the role of Vietnam's legal framework for combating the critical issue of marine plastic pollution in the South China Sea. Integr Environ Assess Manag 2024;20:2088-2106. © 2024 SETAC.

Review on personal protective equipment: Emerging concerns in micro(nano)plastic pollution and strategies for addressing environmental challenges

The COVID-19 pandemic was caused by the SARS-CoV-2 virus, marking one of the most catastrophic global health crises of the 21st century. Throughout this period, widespread use and improper disposal of personal protective equipment (PPE) emerged as a pressing environmental issue, significantly impacting various life forms. During the COVID-19 pandemic, there was a high rate of PEP disposal. An alarming 1.6 × 106 tons of plastic waste each day has been generated since the onset of the outbreak, predominantly from the inadequate disposal of PPE. The mismanagement and subsequent degradation of discarded PPE significantly contribute to increased non-biodegradable micro(nano)plastic (MNP) waste. This pollution has had profound adverse effects on terrestrial, marine, and aquatic ecosystems, which have been extensively of concern recently. Accumulated MNPs within aquatic organisms could serve as a potential route for human exposure when consuming seafood. This review presents a novel aspect concerning the pollution caused by MNPs, particularly remarking on their role during the pandemic and their detrimental effects on human health. These microplastic particles, through the process of fragmentation, transform into nanoparticles, persisting in the environment and posing potential hazards. The prevalence of MNP from PPE, notably masks, raises concerns about their plausible health risks, warranting global attention and comprehensive exploration. Conducting a comprehensive evaluation of the long-term effects of these processes and implementing effective management strategies is essential.

Microplastics and heavy metal contamination along a land-use gradient in a Himalayan foothill river: Prevalence and controlling factors

The co-occurrence of microplastics (MPs) and heavy metals in aquatic systems has raised significant concerns, yet their relationship in freshwater ecosystems remains poorly understood. This study aims to evaluate the prevalence of MPs and factors controlling their distribution in both water and sediment in the Markanda River, Northwest India. MPs were extracted from sediment and water samples using density separation and classified through fluorescence microscopy and Raman spectroscopy. Metal concentrations in river water samples were analyzed using ICP-MS, and their correlation with MP abundance was explored. The results indicated the widespread occurrence of MP pollution across the Markanda River basin, with particle concentrations ranging from 10 to 530 particles L-1 in surface water and 1330-4330 particles kg-1 dry weight (dw) in sediment samples. The variability in MP abundance at sampling sites along the Markanda River courses results from factors such as the proximity of industrial establishments and human habitation, while the influence of grain size on MP distribution appears to be limited. Pellets (88.5 %) and fragments (8.5 %) were the most abundant types of MPs, with polyethylene (45.45 %) and polystyrene (30.9 %) being the dominant forms in water samples. The ICP-MS analysis of heavy metals in water samples indicated elevated levels of As (1.67 to 32.31 ppb) in downstream areas of the river system, influenced by human activities. While metals exhibited correlation with each other, there was a weak association, except for As, with the levels of MPs in the Markanda River. The SEM-EDX analyses to characterize chemical elements absorbed onto the surface of MP showed distinct variations in upstream and downstream sites, with the presence of elements such as Mn, Ni, Cr, Zn, As, Se, and Cu found in downstream areas. We conclude that MPs contaminated with heavy metals potentially threaten the ecological security of freshwater aquatic systems and highlight the importance of management action to reduce plastic pollution worldwide.

Microplastic pollution in surface sediments of Coromandel coastline, South-East Coast, India: Diversity index, carbonyl index, pollution load index, risk fraction and MPs inventory

The investigation along the Coromandel coastline of South-east India focused on assessing microplastics abundance using Simpson's diversity index (DIMP), Degradation-carbonyl index (DgCIMP), Pollution load index (PLIMP) and Ecological risk fraction (RfMP). These indices evaluated the dissemination and transportation of MPs across a 1076 km stretch divided into five zones from Chennai to Kanyakumari. During the wet season, average microplastics abundance (101 ± 36.6 items/kg dw) was lower compared to the dry season (143 ± 56.2 items/kg dw). Notably, 54% and 45% of microplastics were found in the 0.1-0.5 mm size range, with 45% and 64% being colored microplastics, and 80% and 71% being fibers during the wet and dry seasons respectively. Micro-Fourier-transform infrared spectroscopy (μFTIR) analysis showed rayon (34%) and PE (64%) dominance in ports and estuaries during both seasons. Kottaipattinam Port exhibited higher diversity indices (DIMPsh=0.56,DIMPsz=0.66,DIMPco=0.50andDIMPpo=0.65) compared to other zones, with an overall diversity index IDIMP of 0.57. Notably, among the DgCIMP values (n = 96), only 12 fell within the moderate photo-chemical oxidation range (0.16-0.35), while the majority (n = 60) surpassed 0.35 indicating higher oxidation levels, with some (n = 24) exceeding 0.50, signifying extreme oxidation. PLIMP revealed that 42% of sampling stations had very low to negligible MP contamination levels in ports and estuaries. However, ecological risk fraction RfMP values ranged from 10.2 to 13,670, with 27% of values exceeding 1500, indicating higher coastal ecological risk in 13 sampling stations.

Combined exposure of PS-MPs with NaF induces Sertoli cell death and dysfunction via ferroptosis and apoptosis

The individual toxicity of sodium fluoride (NaF) and microplastics (MPs) has been extensively documented. Owing to their high specific surface area, widespread presence and durability, MPs can adsorb a broad spectrum of environmental contaminants into the organism. However, the combined toxicity of NaF and MPs has not been investigated. This study aimed to assess the effects of combined exposure to NaF and MPs on the function of testicular Sertoli cells (SCs) in male mice, and to investigate the underlying molecular mechanisms. The study revealed that combined exposure to NaF and MPs resulted in a decrease in the negative surface charge of MPs, along with an increase in the number of MPs entering the SCs. Through in vivo observation of the testicular pathological structure, spermatogenesis, and cell apoptosis in 180-day-old male mice, we discovered that combined exposure to NaF (80 mg/L) and MPs (10 mg/L) heightened reproductive toxicity compared to the individual exposure groups. This was evidenced by testicular structural defects, impaired spermatogenesis, and increased testicular cell apoptosis. Our in vitro studies showed that NaF (21 μg/mL) and MPs (100 μg/mL) synergistically induced SCs apoptosis and ferroptosis, leading to a reduction in SCs number and dysfunction. This ultimately resulted in structural and functional damage to the testes. Our findings demonstrate, for the first time, the synergistic effects of NaF and MPs on reproductive toxicity in mammals. These insights may provide valuable contributions to co-toxicity studies involving MPs and other environmental pollutants.

Environmental fate of microplastics in high-altitude basins: the insights into the Yarlung Tsangpo River Basin

Microplastics (MPs) have been found in remote high-altitude areas, but the main source and migration process remained unclear. This work explored the characteristics and potential sources of MPs in the Yarlung Tsangpo River Basin. The average abundances of MPs in water, sediment, and soil samples were 728.26 ± 100.53 items/m3, 43.16 ± 5.82 items/kg, and 61.92 ± 4.29 items/kg, respectively, with polypropylene and polyethylene as the main polymers. The conditional fragmentation model revealed that the major source of MPs lower than 4000 m was human activities, while that of higher than 4500 m was atmospheric deposition. Community analysis was further conducted to explore the migration process and key points of MPs among different compartments in the basin. It was found that Lhasa (3600 m) and Shigatse (4100 m) were vital sources of MPs inputs in the midstream and downstream, respectively. This work would provide new insights into the fate of MPs in high-altitude areas.

Assessment of microplastic presence in coastal environments and organisms of Da Nang, Vietnam

This study investigates the presence of microplastics (MPs) in seawater, sediments, and organisms along the coastal areas of Da Nang, Vietnam. The results obtained revealed MP concentrations ranging from 111 to 304 MPs/L in seawater and 2267 to 4600 MPs/kg in sediment. In organisms such as oysters, mussels, crabs, snails, and fish, MP levels ranged from 1.8 to 17.3 MPs/g (wet weight). Fiber MPs were found to be predominant across seawater, sediment, and organisms. The study identified eight, ten, and eleven types of MPs in seawater, sediment, and organisms, respectively, with Nylon, Polytetrafluoroethylene (PTFE), and Ethylene vinyl alcohol (EVOH) being the most prevalent. Notably, MP concentrations were significantly higher in benthic organisms such as oysters, mussels, and crabs compared to fish (t-test, p < 0.05), suggesting habitat dependency. Similar concentrations, shapes, and types of MPs in seawater, sediments, and organisms demonstrate a tendency for MP accumulation in aquatic organisms within the marine environment.

Unveiling microplastics pollution in a subtropical rural recreational lake: A novel insight

While global attention has been primarily focused on the occurrence and persistence of microplastics (MP) in urban lakes, relatively little attention has been paid to the problem of MP pollution in rural recreational lakes. This pioneering study aims to shed light on MP size, composition, abundance, spatial distribution, and contributing factors in a rural recreational lake, 'Nikli Lake' in Kishoreganj, Bangladesh. Using density separation, MPs were extracted from 30 water and 30 sediment samples taken from ten different locations in the lake. Subsequent characterization was carried out using a combination of techniques, including a stereomicroscope, Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FE-SEM). The results showed a significant prevalence of MPs in all samples, with an average amount of 109.667 ± 10.892 pieces/kg3 (dw) in the sediment and 98.167 ± 12.849 pieces/m3 in the water. Small MPs (<0.5 mm), fragments and transparent colored particles formed the majority, accounting for 80.2%, 64.5% and 55.3% in water and 78.9%, 66.4% and 64.3% in sediment, respectively. In line with global trends, polypropylene (PP) (53%) and polyethylene (PE) (43%) emerged as the predominant polymers within the MPs. MP contents in water and sediment showed positive correlations with outflow, while they correlated negatively with inflow and lake depth (p > 0.05). Local activities such as the discharge of domestic sewage, fishing waste and agricultural runoff significantly influence the distribution of polypropylene. Assessment of pollution factor, pollution risk index and pollution load index values at the sampling sites confirmed the presence of MPs, with values above 1. This study is a baseline database that provides a comprehensive understanding of MP pollution in the freshwater ecosystem of Bangladesh, particularly in a rural recreational lake. A crucial next step is to explore ecotoxicological mechanisms, legislative measures and future research challenges triggered by MP pollution.

Sustainable struggling: decoding microplastic released from bioplastics-a critical review

This comprehensive review delves into the complex issue of plastic pollution, focusing on the emergence of biodegradable plastics (BDPs) as a potential alternative to traditional plastics. While BDPs seem promising, recent findings reveal that a large number of BDPs do not fully degrade in certain natural conditions, and they often break down into microplastics (MPs) even faster than conventional plastics. Surprisingly, research suggests that biodegradable microplastics (BDMPs) could have more significant and long-lasting effects than petroleum-based MPs in certain environments. Thus, it is crucial to carefully assess the ecological consequences of BDPs before widely adopting them commercially. This review thoroughly examines the formation of MPs from prominent BDPs, their impacts on the environment, and adsorption capacities. Additionally, it explores how BDMPs affect different species, such as plants and animals within a particular ecosystem. Overall, these discussions highlight potential ecological threats posed by BDMPs and emphasize the need for further scientific investigation before considering BDPs as a perfect solution to plastic pollution.

Activated carbon and their nanocomposites derived from vegetable and fruit residues for water treatment

Water pollution remains a pressing environmental issue, with diverse pollutants such as heavy metals, pharmaceuticals, dyes, and aromatic hydrocarbon compounds posing a significant threat to clean water access. Historically, biomass-derived activated carbons (ACs) have served as effective adsorbents for water treatment, owing to their inherent porosity and expansive surface area. Nanocomposites have emerged as a means to enhance the absorption properties of ACs, surpassing conventional AC performance. Biomass-based activated carbon nanocomposites (ACNCs) hold promise due to their high surface area and cost-effectiveness. This review explores recent advancements in biomass-based ACNCs, emphasizing their remarkable adsorption efficiencies and paving the way for future research in developing efficient and affordable ACNCs. Leveraging real-time communication for ACNC applications presents a viable approach to addressing cost concerns.

Effects of lakeshore landcover types and environmental factors on microplastic distribution in lakes on the Inner Mongolia Plateau, China

Microplastic pollution in freshwater environments has received increasing attention. However, limited research on the occurrence and distribution of microplastics in plateau lakes. This study investigated the microplastic characteristics and influencing factors in lakes with different land cover types on the Inner Mongolia Plateau. Results showed that microplastic abundance ranged from 0.5 to 12.6 items/L in water and 50-325 items/kg in sediments. Microplastics in water were predominantly polypropylene (50.5%), fragments (40.5%), and 50-200 µm (66.7%). High-density (27.9%), fibrous (69.3%), and large-sized microplastics (47.7%) were retained primarily in lake sediments. The highest microplastic abundance in water was found in cropland lakes and grassland lakes, while that in sediments was in descending order of desert lakes > cropland lakes > grassland lakes > forest-grassland lakes. Differences among lake types suggest that agriculture, tourism, and atmospheric transport may be critical microplastic sources. Microplastic distribution was positively correlated with farmland and artificial surface coverage, showing that land cover types related to human activities could exacerbate microplastic pollution in lakes. Redundancy analysis showed that ammonia nitrogen and pH were the key physicochemical factors affecting microplastic distribution in lakes, indicating the potential sources of microplastics in lakes and the uniqueness of microplastic occurrence characteristics in desert saline-alkaline lakes, respectively.

Assessment of meso- and microplastics distribution in coastal sediments and waters at the middle estuary of the Rio De La Plata, Argentina (SW Atlantic Ocean)

Estuarine coastal water and sediments collected from multiple locations within the middle Río de la Plata (RDLP) estuary were analyzed in order to identify the presence of microplastics (MPs, <5 mm) and mesoplastics (MePs, 5-25 mm) in one of the most significant estuaries in the Southwestern Atlantic. The present study represents one of the first researches to survey MPs and MePs contamination in key stations at RDLP estuary. Average concentrations of 14.17 ± 5.50 MPs/L and 10.00 MePs/L were detected in water samples, while 547.83 ± 620.06 MPs/kg (dry weight) and 74.23 ± 47.29 MePs/kg d.w. were recorded in sediments. The greatest abundances were observed in the more anthropized areas, near urban settlements. Fibers were the most conspicuous plastic items in water and sediments, followed by fragments. On the other hand, surface sediments, and 50 cm and 100 cm-depth sediments also presented MPs and MePs indicating they could serve as a stratigraphic indicator for recently formed sediments. The main polymer type identified were acrylic fibers, followed by polypropylene (PP) and polyethylene terephthalate (PET). Besides, SEM-EDX detected the presence of Si, Fe, Ti, Al and Cl onto the plastics' surface. These elements may serve as additives to enhance the plastics' properties, such as in the case of Ti, or they could originate from the environment, like biogenic Si or Fe, and Al possibly as a component of the suspended particles or sediments adhered to the micro or meso plastics. Finally, the results of the present study showed that MPs and MePs are commonly found in waters and also tend to be trapped in sediments of the RDLP estuary supporting the assertion that these areas play a substantial role in influencing the transport, dispersion, and buildup of MPs in estuarine regions.

Insight into microplastics in the aquatic ecosystem: Properties, sources, threats and mitigation strategies

Globally recognized as emergent contaminants, microplastics (MPs) are prevalent in aquaculture habitats and subject to intense management. Aquaculture systems are at risk of microplastic contamination due to various channels, which worsens the worldwide microplastic pollution problem. Organic contaminants in the environment can be absorbed by and interact with microplastic, increasing their toxicity and making treatment more challenging. There are two primary sources of microplastics: (1) the direct release of primary microplastics and (2) the fragmentation of plastic materials resulting in secondary microplastics. Freshwater, atmospheric and marine environments are also responsible for the successful migration of microplastics. Until now, microplastic pollution and its effects on aquaculture habitats remain insufficient. This article aims to provide a comprehensive review of the impact of microplastics on aquatic ecosystems. It highlights the sources and distribution of microplastics, their physical and chemical properties, and the potential ecological consequences they pose to marine and freshwater environments. The paper also examines the current scientific knowledge on the mechanisms by which microplastics affect aquatic organisms and ecosystems. By synthesizing existing research, this review underscores the urgent need for effective mitigation strategies and further investigation to safeguard the health and sustainability of aquatic ecosystems.

Evaluation of microplastic bioaccumulation capacity of mussel (Perna viridis) and surrounding environment in the North coast of Vietnam

This study aimed to identify the presence of microplastics in green mussels (Perna viridis), surface seawater, and beach sediment on the North Coast of Vietnam. The average concentration of MPs in mussels was 3.67 ± 1.20 MPs/g wet weight and 25.05 ± 5.36 MPs/individual. Regarding surface seawater and beach sediments, the MPs concentration was found at 88.00 ± 30.88 MPs/L and 4800 ± 1776 MPs/kg dry weight, respectively. The dominant microplastics shape was fragment with the fractions ranging from 69.86 to 82.41 %. In addition, the size distribution of MPs was mostly in the range of smaller than 50 μm and 1-150 μm (34.17 % and 45.62 % in mussels; 29.65 % and 43.20 % in surface seawater and 40.22 % and 39.40 % in beach sediment, respectively). Polyethylene terephthalate was the major polymer types 49.93-58.44 % of the detected MPs. The risk assessment results based on the polymer types indicated a warning level in several sites.

The path of microplastics through the rare biodiversity estuary region of the northern Bay of Bengal

Due to its harmful effects on ecosystems and human health, microplastic (MP) pollution has become a significant environmental problem on a global scale. Although MPs' pollution path and toxic effects on marine habitats have been examined worldwide, the studies are limited to the rare biodiversity estuary region of Hatiya Island from the northern Bay of Bengal. This study aimed to investigate the MP pollution path and its influencing factors in estuarine sediments and water in rare biodiversity Hatiya Island in the northern Bay of Bengal. Sixty water and sediment samples were collected from 10 sampling sites on the Island and analyzed for MPs. The abundance of MPs in sediment ranged from 67 to 143 pieces/kg, while the abundance in water ranged from 24.34 to 59 pieces/m3. The average concentrations of MPs in sediment and water were 110.90 ± 20.62 pieces/kg and 38.77 ± 10.09 pieces/m3, respectively. Most identified MPs from sediment samples were transparent (51%), while about 54.1% of the identified MPs from water samples were colored. The fragment was the most common form of MP in both compartments, with a value of 64.6% in sediment samples and 60.6% in water samples. In sediment and water samples, almost 74% and 80% of MP were <0.5 mm, respectively. Polypropylene (PP) was the most abundant polymer type, accounting for 51% of all identified polymers. The contamination factor, pollution load index, polymer risk score, and pollution risk score values indicated that the study area was moderately polluted with MPs. The spatial distribution patterns and hotspots of MPs echoed profound human pathways. Based on the results, sustainable management strategies and intervention measures were proposed to reduce the pollution level in the ecologically diverse area. This study provides important insights into evaluating estuary ecosystem susceptibility and mitigation policies against persistent MP issues.

A comprehensive review of micro- and nano-plastics in the atmosphere: Occurrence, fate, toxicity, and strategies for risk reduction

Micro- and nano-plastics (MNPs) have received considerable attention over the past 10 years due to their environmental prevalence and potential toxic effects. With the increase in global plastic production and disposal, MNP pollution has become a topic of emerging concern. In this review, we describe MNPs in the atmospheric environment, and potential toxicological effects of exposure to MNPs. Studies have reported the occurrence of MNPs in outdoor and indoor air at concentrations ranging from 0.0065 items m-3 to 1583 items m-3. Findings have identified plastic fragments, fibers, and films in sizes predominantly <1000 μm with polyamide (PA), polyester (PES), polyethylene terephthalate (PET), polypropylene (PP), rayon, polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC), polyacrylonitrile (PAN), and ethyl vinyl acetate (EVA) as the major compounds. Exposure through indoor air and dust is an important pathway for humans. Airborne MNPs pose health risks to plants, animals, and humans. Atmospheric MNPs can enter organism bodies via inhalation and subsequent deposition in the lungs, which triggers inflammation and other adverse health effects. MNPs could be eliminated through source reduction, policy/regulation, environmental awareness and education, biodegradable materials, bioremediation, and efficient air-filtration systems. To achieve a sustainable society, it is crucial to implement effective strategies for reducing the usage of single-use plastics (SUPs). Further, governments play a pivotal role in addressing the pressing issue of MNPs pollution and must establish viable solutions to tackle this significant challenge.

Implications of solid waste dumps on the microplastic abundance in groundwater in Kollam, India

Water pollution caused by microplastics has garnered increasing attention in recent years due to its potential ecological and human health risks. However, there are very limited studies and a general lack of consensus regarding the presence and negative impacts of microplastics in groundwater. Due to their small size, microplastics can easily be transported at surface as well as subsurface levels, potentially reaching the groundwater table and contaminating the groundwater system This contamination is expected to occur more rapidly in landfill areas and other locations where plastic waste is dumped. In this study, we examined well water samples collected from areas near various dumping sites to assess the abundance and characteristics of microplastics. An average of 12 items/L of microplastics were found in groundwater wells near eight dumping sites in Kollam Corporation. The predominant shape of microplastics in the groundwater samples was fibres, followed by flakes, with black being the predominant colour. The areal extent of solid waste dumping was observed to have an influence on the abundance of microplastics. Additionally, the pH of groundwater near heavy dumping sites was found to be in the acidic range, indicating the intrusion of leachate from dumps into groundwater. The study revealed that the leachate from solid waste dumps is the primary source of microplastics in groundwater. Furthermore, a risk assessment of the microplastic pollution was carried out using an index namely Microplastic Pollution Index and the areas of high risks were identified. The locations having heavy solid waste dumping and those near coastal areas were observed to be at high risk, thereby indicating that both the leachate from dumps and sea water intrusion can cause higher microplastic pollution risk in the groundwater system. The findings of this study are expected to support managers in formulating and implementing effective solid waste management plans to mitigate microplastic pollution in the groundwater system.

Microplastic contamination in bathing areas in the Central Amazon, Itacoatiara, Brazil

Due to the visible abundance of plastic improperly disposed of in the environment, the number of investigations has increased worldwide in different water bodies and biota. Despite this, studies of contamination by microplastics in freshwater environments in the Amazon are scarce. This study investigated microplastic contamination in sediment samples of bathing areas in the Central Amazon, in Itacoatiara, Amazonas, Brazil. A total of 202 microplastic particles were recorded in the five investigated areas that are used for recreation. These results indicate no significant difference in the number of microplastic particles among the establishments; however, the size of the microplastic particles differed significantly between the establishments. Both blue and red microplastic particles were recorded, with blue particles being the most abundant. The microplastic particles were in the form of fibers and fragments. The number of microplastic particles was significantly different between the areas within and adjacent to the bathing areas, though the size of the microplastic particles was not significantly different in the areas within and adjacent to the bathing areas. There was no significant correlation in the establishments in regard to their frequency of use and contamination (number of microplastic particles). This is the first study that indicates the anthropogenic impacts associated with microplastic contamination in recreation areas within the Amazon Forest, an area considered by the world to be of vital importance for conservation. The results of this study indicate that microplastics are present in these bathing areas of the Central Amazon and that contamination in areas used for recreation may be significantly higher than in areas not used for this purpose.

Sources, Degradation, Ingestion and Effects of Microplastics on Humans: A Review

Celluloid, the predecessor to plastic, was synthesized in 1869, and due to technological advancements, plastic products appear to be ubiquitous in daily life. The massive production, rampant usage, and inadequate disposal of plastic products have led to severe environmental pollution. Consequently, reducing the employment of plastic has emerged as a pressing concern for governments globally. This review explores microplastics, including their origins, absorption, and harmful effects on the environment and humans. Several methods exist for breaking down plastics, including thermal, mechanical, light, catalytic, and biological processes. Despite these methods, microplastics (MPs, between 1 and 5 mm in size) continue to be produced during degradation. Acknowledging the significant threat that MPs pose to the environment and human health is imperative. This form of pollution is pervasive in the air and food and infiltrates our bodies through ingestion, inhalation, or skin contact. It is essential to assess the potential hazards that MPs can introduce. There is evidence suggesting that MPs may have negative impacts on different areas of human health. These include the respiratory, gastrointestinal, immune, nervous, and reproductive systems, the liver and organs, the skin, and even the placenta and placental barrier. It is encouraging to see that most of the countries have taken steps to regulate plastic particles. These measures aim to reduce plastic usage, which is essential today. At the same time, this review summarizes the degradation mechanism of plastics, their impact on human health, and plastic reduction policies worldwide. It provides valuable information for future research on MPs and regulatory development.