Microplastics in water systems: A review of their impacts on the environment and their potential hazards

Validating citizen science for community-driven microplastic monitoring and marine protection in Northeast Iceland's Hope Spot

Governments are increasingly monitoring meso- and microplastic (M/MP) pollution in surface waters to develop cost-effective solutions. While citizen science is widely used in programs like the EU's Marine Litter Watch and NOAA's sampling in the U.S., these efforts primarily focus on macro litter, leaving gaps in M/MP data, especially in under-sampled regions like Icelandic waters. This study addresses this gap through a citizen science initiative (2019-2023) that monitored M/MP pollution in the "Northeast Iceland Hope Spot." Fifty-eight trawl samples were collected from whale-watching and expedition vessels using a low-tech aquatic debris instrument (LADI) or a high-speed AVANI trawl. M/MP were present in 86 % of samples, with an average density of 0.02 ± 0.03 particles/m3. Concentrations varied significantly between sites (p = 0.005), peaking in Grímsey (0.070 ± 0.03 particles/m3), followed by Eyjafjörður (0.006 ± 0.04 particles/m3) and Skjálfandi Bay (0.004 ± 0.03 particles/m3). Mesoplastics comprised 44 % and microplastics 56 %, primarily polyethylene (47 %) and polypropylene (39 %)-common materials in fishing gear and household plastics. These findings suggest that local currents and fishing activities influence M/MP distribution. Comparison with previous studies validates the use of the presented citizen science methods for tracking floating M/MP in coastal waters and highlights their value in shaping marine conservation policies, particularly in vulnerable subarctic ecosystems.

Microplastic footprints in sharks and rays: First assessment of microplastic pollution in two cartilaginous fishes, hardnose shark and whitespotted whipray

Microplastic (MP) pollution is an emerging environmental problem worldwide and has caused widespread concern both in terrestrial and aquatic ecosystems due to their potential impacts on the human health, and health of aquatic organisms and the environment. Little is known about the exposure of top marine predators to MP contamination (debris 0.1μm - <5mm, also called MPs). For the first time, MPs have been characterized in carnivore demersal elasmobranch specimens of hardnose shark Carcharhinus macloti, and the whitespotted whipray Maculabatis gerrardi. The specimens were from the Persian Gulf and Sea of Oman, and MPs were extracted from their intestines, gills, and skin. MPs were found in every sampled tissue examined: this is higher pollution than previously reported for elasmobranch. The total MPs for these organs were 12.6 MPs/g body mass of sharks, and 17.8 MPs/g in the whiprays on average. The most common MPs found were fibres (59%), and filaments (35%); pointing towards fishing gears and limited wastewater treatment. Fragments, films, and foams were <2.1 %; a less abundant problem. The most abundant MPs sampled were ∼0.5 mm ≤ L< 1 mm (when the limit of detection was 0.1 mm), and blue was the most common MP color hinting intake due to visual confusion. Polycarbonate and nylon were the most abundant polymers in the MPs recovered. The overall findings show that C. macloti and M. gerrardi are vulnerable to plastic and it reflects the critical state of their habitat.

Microplastics in marine fish: a mini-review on presence, classification, and impacts

Plastic production has experienced exponential growth in recent years due to its diverse industrial applications, low cost, and high availability, also causing issues, since plastic waste in aquatic ecosystems transforms into microplastics (MPs) through mechanical and weathering processes. Microplastics are distributed ubiquitously in water bodies, where they can be ingested by a wide aquatic organism range, including fish, which have been used as bioindicators to assess microplastic presence and toxicity. Research has revealed microplastic presence in various fish species worldwide; the most common characteristics are fibers and fragments of blue, black, and transparent colors, and polyethylene, terephthalate, polypropylene and cellophane chemical composition. Experimental studies under laboratory conditions have demonstrated microplastics impact on fish, showing physical, immunological, and hematological damage, and oxidative stress ultimately leading to organisms' death. However, laboratory results do not necessarily predict impacts on wild fish due to different conditions to which the organisms are exposed. Therefore, further research needs to simulate real scenarios faced by wild fish in the marine environment, providing greater certainty about microplastic impacts and negative effects.

Microplastic contamination in threatened wild felids of India: Understanding environmental uptake, feeding implications, and associated risks

While the presence of microplastics (MPs, <5 mm) in various aquatic organisms is well-documented, studies on the accumulation of MPs in terrestrial predators remain limited worldwide, including in India. This study aims to evaluate, for the first time, the occurrence of MPs in the scat of mid-sized felids-fishing cat and jungle cat-from their overlapping habitat in the Gangetic Estuary of India. The risk assessment of MPs and management recommendation for MP mitigation was also discussed in this context. Notably, our study is the first to report the presence of MPs and mesoplastics in fishing cat from India and jungle cat globally. The abundance of MPs was found to be higher in jungle cat (12.6 ± 1.93 MP/g d.w) compared to fishing cat (10.5 ± 2.12 MP/g d.w) in the Gangetic estuary. Furthermore, fiber-shaped (70.37%) and 1-5 mm-sized (47.73%) MPs predominated in both felid species, while fiber bundles were observed only in jungle cat. Red-colored MPs (27.62%) were predominantly found in fishing cat, whereas transparent MPs (33.33%) were more common in jungle cat. Scanning electron microscopy revealed possible environmental and digestive degradation marks on the MPs. A total of seven synthetic and one natural polymer were identified, with Ethylene Vinyl Alcohol (55.56%) being predominant in fishing cat and Polyethylene (33.33%) more common in jungle cat. Polymer risk assessment indicated that the MPs in fishing cat fall into the danger category, Group IV (PHI 100-1000), while jungle cat possess high threat under extreme danger category, Group V (PHI >1000). The observed MPs and mesoplastics in felids probably come from adjacent environmental uptake and/or accumulate through trophic transfer from prey items. The evidence of MPs in felids may pose a threat to the big cat-Royal Bengal tigers in the Sundarbans. Therefore, various landscape-based policy implementations are recommended to mitigate MP pollution.

Reefs of Brachidontes exustus and Petaloconchus spp. as traps and sink for microplastics in tropical coastal areas

Microplastics (MPs) are emerging contaminants in marine environments. This study quantified, chemically identified, and described MPs in reefs of Brachidontes exustus and Petaloconchus spp. on the tropical coast of Brazil. Samples were collected in reefs of northeastern Brazil in the dry (February) and rainy (July) seasons of 2023. MPs were classified (shape and color), measured, and counted. MPs were present in all samples. Most MPs were transparent fibers, with more particles in Brachidontes reefs and during the rainy season. MPs were mainly polystyrene, polypropylene, polyester, and polyamide. The characteristics of reefs and seasonal changes in rainfall are the main drivers of the accumulation of MPs, and the shape and chemical composition of particles reveal that their principal source is probably the textile and apparel industry. The trapping of MPs in Petaloconhus spp. and Brachidontes exustus reefs reveals that biogenic reefs may be a sink for microplastics in tropical coastal areas.

First Evidence of Microplastics Burden in Surface Waters of Budhabalanga Estuary, Chandipur, Eastern India: Potential Threat to Aquatic Ecosystem

Microplastic pollution has emerged as a new global concern because of its ubiquitous and persistent nature. Due to the rising use of plastics and discharge of plastic waste into coastal water bodies from point and non-point sources, the occurrence of microplastics along coastal ecosystems has become very prevalent. The current study is the first of its kind to evaluate the presence of microplastics in the surface water of river estuary along the coast of Odisha. Six GPS-fixed locations were used to collect the surface water samples from the Budhabalanga river estuary in Chandipur, Odisha, India. The samples were then subjected to further investigation to determine the types of microplastics present. The average microplastic abundance, according to our findings, ranged from 9.33 ± 2.11 items L-1 to 28.50 ± 2.77 items L-1. Microplastics come in a variety of colours and shapes, but the most prevalent kind is fibre-shaped and black in colour. The pollution load index of the sampling area was calculated to be 4.25 which is categorized under ecological risk level I. FE-SEM images clearly showed the topology of microplastics and ATR-FTIR analysis confirmed the presence of polyethylene, polypropylene, polyvinyl chloride (PVC), nylon, polycarbonate (PC), ethylene vinyl acetate (EVA) and polystyrene (PS) at sampling stations. Our investigation provides useful information that helps to reduce the ecological risk in habitats connected with contaminated sites, including both aquatic and terrestrial habitats.

Biophysics-guided uncertainty-aware deep learning uncovers high-affinity plastic-binding peptides

Plastic pollution, particularly microplastics (MPs), poses a significant global threat to ecosystems and human health, necessitating innovative remediation strategies. Biocompatible and biodegradable plastic-binding peptides (PBPs) offer a potential solution through targeted adsorption and subsequent MP detection or removal from the environment. A challenge in discovering plastic-binding peptides is the vast combinatorial space of possible peptides (i.e., over 1015 for 12-mer peptides), which far exceeds the sample sizes typically reachable by experiments or biophysics-based computational methods. One step towards addressing this issue is to train deep learning models on experimental or biophysical datasets, permitting faster and cheaper evaluations of peptides. However, deep learning predictions are not always accurate, which could waste time and money due to synthesizing and evaluating false positives. Here, we resolve this issue by combining biophysical modeling data from Peptide Binder Design (PepBD) algorithm, the predictive power and uncertainty quantification of evidential deep learning, and metaheuristic search methods to identify high-affinity PBPs for several common plastics. Molecular dynamics simulations show that the discovered PBPs have greater median adsorption free energies for polyethylene (5%), polypropylene (18%), and polystyrene (34%) relative to PBPs previously designed by PepBD. The impact of including uncertainty quantification in peptide design is demonstrated by the increasing improvement in the median adsorption free energy with decreasing uncertainty. This robust framework accelerates peptide discovery, paving the way for effective, bio-inspired solutions to MP remediation.

A preliminary assessment of microplastics in the waters and sediments of the second-largest freshwater lagoon in India

Pulicat is India's second-largest freshwater lagoon having unique biological ecosystem and economical importance. The lagoon systems are highly polluted by the microplastics (MP) due to anthropogenic activity and microplastics are highly emerging kind of contaminant in the environment. Samples were collected from a part of the lagoon near the mouth region. Morphological identification of microplastics with microscope and polymer identification using ATR-FTIR and Micro-Raman spectroscopy was carried out. From the result, average abundance of the MP particles in surface water ranges 3.12 ± 1.53 particles per 1000 l and 701 ± 198 particles per kg for sediments, respectively. Microplastics < 1 mm (1-1000 microns) are dominant in size. Fibres, fragments and films were most occupied in physical form, respectively, in microplastic samples and polypropylene (PP) and polyethylene (PE) were the predominant polymer types composited in MP particles. This study concludes that Pulicat lagoon is significantly polluted by microplastic, which is mostly contributed by fishing and mismanagement of plastic wastes.

Enhancing the aging of polystyrene microplastics through a flow-through electrochemical membrane system: Mechanism of confinement effect

Microplastics (MPs) are emerging pollutants in aquatic environments that pose serious health risks, and traditional wastewater treatments are ineffective at removing them. In this study, a flow-through electrochemical membrane (F-T) system was developed to simultaneously separate and age polystyrene microplastics (PS-MPs) in water. Under membrane pressure, PS-MPs were tightly pressed onto the surface of membrane electrode, forming a confinement space. The confinement effect overcomes the short lifetime of free radicals and accelerates the aging process of PS-MPs. This study identified the optimal conditions for aging PS-MPs in the F-T system, characterized the material properties before and after aging, and analyzed the degradation intermediates. After 8 h of treatment, the oxygen-to-carbon ratio (O/C) of the PS-MPs following the F-T system was 2.00 times greater than that following the traditional flow-by (F-B) system. In addition, the unit energy consumption (kW·h/g) for the aging of PS-MPs in the F-T system was 645.19 kW·h/g, which was 3.70 times lower than the F-B system. Free radicals, especially O2•- and •OH, played a major role in PS-MPs aging. Free radicals attack the main chain of PS-MPs, leading to subsequent chain breakage, hydrogen abstraction, and rearrangement reactions. After aging in the F-T system, the crystallinity, molecular weight, and zeta potential of the PS-MPs significantly decreased. In addition, carbon-centered environmental persistent free radicals formed on the surface of the PS-MPs. This study presents an energy-efficient method for the remediation of MPs in water and suggests that the aging efficiency can be increased through confinement.

Concentrations and human health risks attributed to potentially toxic elements (PTEs) in water resources in China: Systematic review and meta-analysis

Long-term exposure to potentially toxic elements (PTEs) increases carcinogenic and non-carcinogenic risks in the exposed population. The current study was conducted with the aims of meta-analysis concentrations of PTEs including Arsenic (As), Cadmium (Cd), Lead (Pb), Mercury (Hg), Nickel (Ni) and Copper (Cu) in the water resources and human health risk assessment for adult males and female consumers in China. Search was performed in international databases including Web of Science, Scopus, PubMed, Embase and Google Scholar (gery literature) from January 1, 2005 to April 1, 2024. The concentration of PTEs was meta-analyzed using random effects model in water resources (surface water and groundwater) and location of study (urban and rural locations) subgroups. Human health risk assessment due to PTEs in water from ingestion and dermal contact pathways was estimated using target hazard quintet (THQ) and carcinogenic (CR) in adult males and female consumers in China. One hundred and twenty-six papers with 237 data-reports (n = 13,083) were included in this study. The rank order of PTEs based on pooled concentration was As (12.6530 µg/l) > Cu (11.1810 µg/l)> Ni (2.4950 µg/l) > Pb (2.0660 µg/l) > Cd (0.5370 µg/l) > Hg (0.3600 µg/l). The rank order of PTEs based on percentage studies higher than standard limits was As (28.37 %) > Pb (16.67 %) > Hg (11.86 %) > Ni (9.91 %) > Cd (7.48 %) > Cu (2.38 %). The pooled concentration of Pb, Ni, Hg and Cu in surface water resources was higher than groundwater but concentration of As and Cd in groundwater water was higher than surface water. The rank order of PTEs based on percentage studies with the high non-carcinogenic risk (THQ ≥ 1) for male was As (30.49 %) > Cd (8.09 %)> Hg (6.90 %) > Ni (3.60 %)> Cu (3.39 %) > Pb (2.50 %) and for female, As (29.78 %) > Cd (8.09 %)> Hg (6.90 %) > Cu (3.39 %) > Ni (2.70 %)> Pb (1.25 %). The rank order of PTEs based on percentage studies with high carcinogenic risk (TCR ≥ 1E-4) for male was As (60.28 %) > Cd (33.33 %) and for female, As (56.73 %) > Cd (29.93 %). Therefore, to reduce the carcinogenic and non-carcinogenic risks of PTEs especially As, continuous monitoring and control release of As into water resources through novel approaches is recommended.

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.

From plankton to fish: The multifaceted threat of microplastics in freshwater environments

The detrimental impact of emerging pollutants, specifically microplastics (MPs), on the ecological environment are receiving increasing attention. Freshwater ecosystems serve as both repositories for terrestrial microplastic (MP) sources and conduits for their subsequent entry into marine environments. Consequently, it is imperative to rigorously investigate the toxicological effects of MPs on freshwater ecosystems. This article provides a comprehensive analysis of the ecological toxicity effects of MP pollution, both in isolation and in combination with other pollutants, on freshwater aquatic organisms, including plankton, benthic organisms, and fish. The review elucidates potential mechanisms underlying these effects, which encompass oxidative stress, metabolic disorders, immune and inflammatory responses, dysbiosis of the gut microbiota, DNA damage, and cell apoptosis. This paper advocates for the integrated application of multi-omics technologies to investigate the molecular mechanisms underlying the toxicity of MPs to freshwater aquatic organisms from interdisciplinary and multifaceted perspectives. Additionally, it emphasizes the importance of enhancing research on the compounded pollution effects arising from various pollution modes, particularly in conjunction with other pollutants. This study aims to establish a foundation for assessing the ecological risks posed by MPs in freshwater ecosystem and offers valuable insights for the protection of aquatic biodiversity and ecosystem stability.

Plastics in dermatology: A review and solutions

Hazards to human and planetary health are present at every stage of the plastic life cycle, yet plastic production is projected to triple by 2060. This review focuses on three key areas: the life cycle of plastic, the impact of microplastics and their associated chemicals, along with recommendations to reduce plastic use. In dermatology, micro- and nanoplastics are especially problematic as they are present in over 90% of personal care products. They have been detected in utero, absorbed through the skin and found in the lungs and gastrointestinal tract. Numerous in vitro and animal studies have substantiated the negative impact of micro- and nanoplastics but gaps remain with regards to their effect on human health. In spite of this limitation, we review the evidence to date and offer evidence-based recommendations which can reduce plastic production, enhance health outcomes and promote environmental justice.

Aquatic microplastics research in the ASEAN region: Analysis of challenges and priorities

Research on microplastics must be harmonized. Therefore, we thoroughly evaluated in the Association of Southeast Asian Nations (ASEAN) region, addressing challenges and priorities in protocol harmonization and microplastics research promotion. Of the 615 papers searched by the Web of Science, 164 were used for this systematic review. The number of ASEAN research articles has increased over time. Examination of research protocols in various sampling environments revealed several challenges: 1) Disparities in access to sampling locations affect the research extent; 2) Outdated protocols and limited access to technologies such as FTIR (Fourier-transform infrared) spectroscopy result in less harmonized and potentially lower-quality data; and 3) Insufficiently detailed methods and QA/QC information hampers comparability. We offer procedure updates to overcome these limitations and cover environmental microplastic study gaps. Other countries in the Global South may encounter similar challenges, making this review a valuable contribution to advancing global microplastics research and fostering international collaboration.

Emission characteristics analysis on microplastics by inorganic sludge discharged from recycling processes of agricultural waste vinyl in Korea

Globally, various policies are being implemented to phase out plastic, and South Korea has set targets to reduce waste and increase recycling rates by 2030. Concerns about managing microplastic pollution are growing. Most advanced research has primarily focused on aquatic ecosystems. This has left a gap in data on residues in sludge generated from agricultural waste recycling processes. Therefore, environmental analysis (leaching tests, heavy metal and microplastics content, etc.) was carried out using the inorganic sludge discharged from the agricultural waste recycling process to establish national data for various environmental analyses in this study. Specifically, inorganic sludge was selected as a sample from the agricultural waste recycling process since it would be recycled as a filling or covering material in agricultural soil. Therefore, this study analyzed and assessed the content of harmful substances and microplastics in the inorganic sludge generated from agricultural waste recycling processes. As a result, it was revealed the detection of unregulated items such as Al (leaching: 1.54 mg/L, content: 23,870 mg/kg), Fe (leaching: 0.48 mg/L, content: 27,453 mg/kg), and Mn (leaching: 0.06 mg/L, content: 649 mg/kg). Among regulated items, Cu (35.96 mg/kg), Ni (8.77 mg/kg), Pb (6.47 mg/kg), and Zn (178.39 mg/kg) were detected within the legal concentration limits. As for microplastics, the number (1814 particles) and mass (446.54 μg/g) were detected. However, the impact of microplastics is not identified clearly yet. Therefore, if the study results and subsequent accumulation of data by expanding the research target waste can be utilized, it is expected that this could serve as fundamental data for establishing policies or legislation for microplastic management systems.

Microplastic abundance in the surface water of tropical estuarine fronts

Estuarine fronts are formed due to sharp density discontinuities resulting from the convergence of different water masses. This study, conducted in May and August of 2022 during the southwest monsoon season, focuses on assessing the role of estuarine fronts at Kuala Terengganu estuary in the accumulation of microplastics in surface seawater. The Terengganu River basin area covers approximately 4600 km2 and consists of two main tributaries that drain into the Kuala Terengganu estuary. Microplastic samples were collected from three areas, the plume, front, and shelf, utilizing two methods: manta net (> 350 µm) and bucket-water sampling (> 20 µm). Results indicate that the estuarine front consistently exhibited higher microplastic concentrations than the plume and shelf regions throughout the study period, with bucket-water sampling contributing significantly to the abundance. Specifically, peak concentrations occurred during the ebb tide at the frontal region in both months, reaching 5761.703 particles m-3 and 12,687.437 particles m-3, respectively. The microplastics, predominantly transparent fibers smaller than 1000 µm, mostly showed signs of oxidative and mechanical weathering through SEM-EDS analysis, providing insights into their fate in estuarine surface waters. FTIR spectroscopy revealed polypropylene, polyethylene, and polyamide as the dominant polymers. These findings establish a baseline for microplastic abundance at the estuarine front of the Kuala Terengganu estuary and may inform future strategies for mitigating and recovering microplastic contamination in aquatic environments.

More than just sweet: current insights into microplastics in honey products and a case study of Melipona quadrifasciata honey

Honey, traditionally known as a pure and natural substance, has become an unexpected reservoir for microplastic contamination. This study consisted of an experimental investigation to assess the occurrence of microplastics in honey produced by Melipona quadrifasciata, a native bee species in Brazil. Our investigation covers eight areas (one sample per area), including built and vegetated areas located in São Paulo city, Brazil, to understand the distribution of microplastics in these environments. Honey samples (10 mL) were collected using a syringe and sent to the laboratory for further analysis. Microplastics extracted from honey samples were characterized under a stereomicroscope to determine their size, color, and morphology. Also, the polymer type was determined by FTIR analysis. All honey samples (100%) showed microplastics. The predominant particles displayed a fiber shape with a size below 299 μm and a transparent color and were primarily composed of polypropylene. Their concentrations ranged from 0.1 to 2.6 particles per mL of honey, raising concerns about their potential impact on bee populations and human consumers. This study underscores the need for further research on the sources and implications of microplastic contamination in Melipona quadrifasciata honey, shedding light on the broader issue of environmental plastic pollution and its impact on pollinators.

The crucial factor for microplastics removal in large-scale subsurface-flow constructed wetlands

Constructed wetlands (CWs) are an effective method for removing microplastics (MPs). Nevertheless, the understanding of the impact of various parameters on MPs removal within CWs remains incomplete. Through field investigations of large-scale CWs and the application of machine learning methods with an interpretable attribution technique (the Shapley Additive Explanation), we investigated the critical factors influencing MPs removal within CWs. The MPs abundance in the influent and the inlet of Z-CW (400.1 ± 20.8 items/L and 699.6 ± 50.6 items/kg) was significantly higher compared to that in M-CW (138.8 ± 20.5 items/L and 166.5 ± 36.8 items/kg), with no significant difference observed in the effluent. The primary characteristic of MPs is their fibrous and transparent appearance. The MPs removal range from 87.9% to 95.5 %, influenced by the types and characteristics of MPs, physical and chemical parameters, biofilms, and different processes. Among these factors, dissolved organic carbon with high humic content, aromaticity, and carboxyl abundance may serve as a crucial factor in MPs removal. The results of this study highlight the significance of physical and chemical parameters for the MPs removal in CWs, providing the necessary theoretical data for the construction of future large-scale engineering applications.

Morphometric characteristics and spatiotemporal heterogeneity of microplastics on the north-east coast of India

The study analysed microplastics (MPs) in surface waters along the north-east coast of India and focused on the spatiotemporal distribution and morphometric characteristics of 800 particles for environmental insights. The MPs were consistently present in all water masses, with an average abundance of 0.67 ± 0.66 particles/m3 during the monsoon and 0.12 ± 0.08 particles/m3 post-monsoon. Fragments and fibers were dominant in both seasons, comprising over 83 % and 12 %, respectively. In terms of colours, blue was significantly dominant during the post-monsoon (H, χ2 (5) = 15.38, p < 0.01); however, such variation was absent during the monsoon. Spatially, significant variance in abundance (F4, 34 = 8.542; p < 0.01) and across colours and forms during the monsoon was correlated with land-based inputs from the Hooghly River. FTIR analysis revealed ten polymer types, predominantly polyethylene (44 %). SEM observations indicated that 80 % of particles exhibited polymer ageing from oxidative weathering. The size distribution of MPs varied notably, with a higher proportion of < 0.3 mm (16.7 %) during the monsoon, possibly due to increased particle disintegration. The study noted MPs had low to moderate circularity, with increased irregularity during the monsoon due to heavy precipitation and river flushing. An initial risk assessment of MP pollution in surface waters on the north-east coast revealed a low-risk state. Acrylonitrile butadiene styrene (ABS) was identified as the most hazardous MP polymer. A wide range of toxic trace elements were found in MPs in these waters. The findings from the study deepen our knowledge of MPs and their fate in the pelagic zone, which supports the development of science-based policies that effectively reduce MP pollution.

Improving properties of chitosan/polyvinyl alcohol films using cashew nut testa extract: potential applications in food packaging

Cashew nut testa, a by-product of cashew nut processing, is abundant in phenolic compounds and exhibits strong antioxidant properties, making it a potential additive for enhancing the antioxidant properties of biodegradable films used in food packaging. This study explores the fabrication of biodegradable chitosan/polyvinyl alcohol films incorporating varying concentrations of cashew nut testa extract (CNTE; 0, 1, 2 and 3% v/v) and evaluates their physical, structural, mechanical, optical and antioxidant properties. The results demonstrate that increasing extract concentration generally increased the thickness, tensile strength, Young's modulus, thermal stability and antioxidant capacity of the films, while reducing the moisture content, swelling degree, elongation at break, and light transmittance. Specifically, the film with 3% extract showed approximately 11% lower moisture content and 31% lower swelling degree compared with the plain film. It also displayed the highest tensile strength and Young's modulus at 28.63 and 147.35 MPa, respectively. Microstructural analysis revealed that the incorporation of CNTE resulted in a smoother and slightly denser film structure. Antioxidant activity, determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay, was not detected in the plain film but increased with increasing extract concentration. The film with 3% CNTE exhibited the highest antioxidant activity of 58.93 µmol Trolox equivalents (TE) g-1 film. This study highlights the potential of CNTE as an effective edible additive for developing antioxidant and ultraviolet barrier films with improved mechanical strength and water resistance for food packaging applications.

Microplastics: The imperative influencer in blueprint of blue economy

The burgeoning issue of microplastic pollution in marine ecosystems has emerged as a significant concern, presently multifaceted difficulty to the sustainability and prosperity of the blue economy. This review examines the intricate link between microplastics (MPs) and the blue economy (BE), exploring how microplastics infiltrate marine environments, their persistence, and their impacts on economic activities reliant on healthy oceans in a global scenario. Diminished seafood quality and quantity, degraded coastal aesthetics affecting tourism revenues, and increased operational costs due to fouling and contamination are among the economic repercussions identified. Additionally, the review discusses the potential long-term consequences on human health and food security, emphasizing the urgency for proactive mitigation measures and policy interventions in the global scenario. The study highlights the interconnectedness of the blue economy and environmental health, prompting a comprehensive strategy to mitigate microplastic pollution. It calls for collaborative efforts among stakeholders, including policymakers, industries, academia, and civil society, to develop innovative strategies for combating microplastic pollution and promoting sustainable blue economic practices. In conclusion, the review stresses the pressing need for concerted action to address microplastic threats to the blue economy, recommending science-based policies, technological innovations, and public awareness campaigns to protect marine ecosystems and ensure the resilience and prosperity of ocean-dependent economic activities.

Microplastics in aquaculture environments: Current occurrence, adverse effects, ecological risk, and nature-based mitigation solutions

Microplastics pose detrimental effects on the environment, aquatic products, and human health. This comprehensive analysis highlights the repercussions of microplastic contamination within aquaculture. Microplastics in aquaculture are primarily from land-based plastic waste, tourism-related disposal, shipping activities, fisheries/aquaculture, and atmospheric deposition. In aquaculture environments, microplastics have the potential to discharge harmful additives, attract pollutants, degrade the aquaculture setting, and induce toxicological effects. These particles pose ecological risks and can impact human health. Assessing the destiny of microplastics in aquaculture ecosystems is crucial to determining the role of aquaculture in contributing to microplastic contamination within the watershed. It particularly emphasizes the ecological consequences for aquaculture species and the subsequent health threats for humans. The review strongly supports strict regulations to control and limit microplastic presence within aquaculture ecosystems. Clear regulations are essential for reducing microplastics in aquaculture, thereby ensuring food safety. A novel nature-based solution is proposed using methods like microplastic biofilters, biodegradation, and wetlands. These innovations can be conducted in aquatic ecosystems to serve as microplastic biofilters, effectively eliminating waterborne microplastics. In the future, however, it is crucial to develop additional emergency treatment measures to avoid the potential negative impacts of microplastics on both aquaculture and human health.

Unraveling microplastic pollution patterns in sediments of a river system: The combined impacts of seasonal changes and waterway differences

Microplastic (MP) distribution in river sediment, influenced by water regimes and pollution sources, remains understudied in the current literature. This study examines the combined impacts of seasonal variation and waterway differences on MP concentration in the sediment of the Saigon River and its tributaries, while identifying potential sources. Paired sediment samples were collected from eleven sites along the river and its tributaries during rainy and dry seasons. MPs from these 44 samples were separated, quantified, and characterized for a comprehensive assessment. The results revealed that MP concentrations in sediments ranged from 140 to 1200 items kg-1, with predominant characteristics of fiber particles, white color, and particle sizes ranging from 200 to 500 μm. During the rainy season, MP concentrations were similar between the river (584 items kg-1) and tributaries (553 items kg-1), while during the dry season, tributaries exhibited statistically higher MP concentrations (737 items kg-1) than the river (351 items kg-1). Notably, the river, despite being farther from the sources, had a higher proportion of smaller MPs (<200 μm), while larger particles (>200 μm) were more prevalent in tributaries. These discrepancies are attributed to the combined impacts of water flow patterns and pollution sources, derived from residential, industrial, and agricultural activities. In brief, MP pollution in the river and tributary sediments is influenced by the interplay of seasonal variation and waterway characteristics, determined by water flow patterns and pollution sources. These findings emphasize the need for specific management strategies that account for spatial and temporal variations in MP distribution.

The biochemical mechanisms of plastic biodegradation

Since the invention of the first synthetic plastic, an estimated 12 billion metric tons of plastics have been manufactured, 70% of which was produced in the last 20 years. Plastic waste is placing new selective pressures on humans and the organisms we depend on, yet it also places new pressures on microorganisms as they compete to exploit this new and growing source of carbon. The limited efficacy of traditional recycling methods on plastic waste, which can leach into the environment at low purity and concentration, indicates the utility of this evolving metabolic activity. This review will categorize and discuss the probable metabolic routes for each industrially relevant plastic, rank the most effective biodegraders for each plastic by harmonizing and reinterpreting prior literature, and explain the experimental techniques most often used in plastic biodegradation research, thus providing a comprehensive resource for researchers investigating and engineering plastic biodegradation.

Are microplastics a new cardiac threat? A pilot study with wild fish from the North East Atlantic Ocean

Global environmental contamination by microplastics (MPs) is a growing problem with potential One Health impacts. The presence of MPs in vital organs, such as the heart, is of particular concern, but the knowledge is still limited. The goal of the present pilot study was to investigate the potential presence of MPs in the heart of wild specimens of three commercial fish species (Merluccius merluccius, Sardina pilchardus, and Trisopterus luscus) from the North East Atlantic Ocean. Heart samples from 154 fish were analysed for MP content (one heart sample per fish). A total of 44 MPs were recovered from heart samples from the three species. MPs had varied chemical composition (5 polymers), shapes (4) and colours (5). Differences in the profile of the MPs among species was observed (p ≤ 0.05). Thirty fish (19%) had MPs in their hearts, with a total mean (±SD) concentration of 0.286 ± 0.644 MPs/fish. S. pilchardus had the highest heart contamination (p ≤ 0.05). There were no significant (p > 0.05) differences between M. merluccius and T. luscus. These findings in fish with different biological and ecological traits together with literature data suggest that heart contamination likely is a disseminated phenomenon. Therefore, further research on the presence of MPs in the cardiovascular system and its potential health effects is very much needed.

Evidence of Oxidative Stress as a Mechanism of Pharmaceutical-Induced Toxicity in Amphibians

Amphibians, which are essential components of ecosystems, are susceptible to pharmaceutical contamination, a phenomenon of increasing concern owing to the widespread consumption and detection of pharmaceutical compounds in environmental matrices. This review investigates oxidative stress (OS) as the primary mechanism of drug toxicity in these organisms. The evidence gathered reveals that various pharmaceuticals, from antibiotics to anesthetics, induce OS by altering biomarkers of oxidative damage and antioxidant defense. These findings underscore the deleterious effects of pharmaceuticals on amphibian health and development and emphasize the necessity of incorporating OS biomarkers into ecotoxicological risk assessments. Although further studies on diverse amphibian species, drug mixtures, and field studies are required, OS biomarkers offer valuable tools for identifying sublethal risks. Furthermore, the development of more refined OS biomarkers will facilitate the early detection of adverse effects, which are crucial for protecting amphibians and their ecosystems. Ultimately, this review calls for continued research and mitigation strategies to safeguard biodiversity from pharmaceutical contamination.

Characterization of microplastics in soil, leachate and groundwater at a municipal landfill in Rayong Province, Thailand

Recent years have witnessed a dramatic increase in global plastic production, leading to heightened concerns over microplastics (MPs) contamination as a significant environmental challenge. MP particles are ubiquitously distributed across both continental and marine ecosystems. Given the paucity of research on MPs in Thailand, particularly regarding MPs contamination in terrestrial environments, this study focused on investigating the distribution and characteristics of MPs in a landfill area. We collected 15 soil samples, 2 leachate samples, and 7 groundwater samples from both inside and outside a municipal landfill situated in the urbanized coastal region of Rayong Province. Our findings revealed variability in MPs concentration across different sample types. In soil, the MP count ranged from 240 to 26,100 pieces per kg of dry soil, 58.71 % of all sample sizes are lower than 0.5 mm. Similarly, the size found in the leachate sample, and the average MP in the leachate samples was 139 pieces per liter of MPs. The groundwater samples showed a fluctuation in MPs count from 18 to 94 pieces per liter, and the size of MPs ranged mostly from 0.5 to 1 mm. The predominant forms of MPs identified were sheets, followed by fragments, fibers, and granules. According to μ-FTIR analysis, the majority of the MPs were composed of polyethylene and polypropylene, commonly used in plastic packaging and ropes. The observed high concentrations and extensive distribution of MP contamination underscore the urgency for further studies and effective management strategies to mitigate the adverse impacts of this pollution on various organisms and ecosystems.

Insight into the fate of bioplastic and similar plant-based material debris in aquatic environments via continuous monitoring of their leachate composition - Release of carbon, metals, and additives

Currently, the environmental problems associated with plastic production and waste, such as the consequences of worldwide pollution of natural waters with microplastics, have led to the seeking of alternative materials that can at least partially replace conventional petroleum-based plastics. Substitute materials include bioplastics and similar plant-based materials or their composites. However, their fate when disposed of in unintended environments (e.g., water bodies) remains largely unknown, while such information is highly desirable prior to massive expansion of exploiting such materials. This study aims to contribute filling this knowledge gap. Specifically, 19 different types of bioplastic and similar plant-based material debris (corresponding to the size of microplastics) were kept in long-term contact with water to mimic their behaviour as water pollutants, and the leachates were continuously analysed. Eighteen of the 19 investigated materials released significant amounts of dissolved organic carbon-up to 34.0 mg per g of debris after 12 weeks of leaching. Each leachate also contained one or more of the following elements: Al, B, Ba, Ca, Fe, K, Mg, Mn, N, Na, P, Si, Ti, and Zn. Non-targeted analysis aimed at providing more specific insight into the leachate composition tentatively revealed 91 individual chemicals, mostly fatty acids and other carboxylic acids, phthalates, terephthalates, adipates, phenols, amides, alcohols, or organophosphates. Based on the compound characteristics, they might be additives, non-intentionally added substances, as well as their degradation products. In general, the current results imply that bioplastics and similar plant-based materials should be considered complex materials that undergo industrial processing and comprise additives rather than harmless natural matter. Additionally, various compounds can release from the bioplastic and similar plant-based material debris when deposited in water. It might have consequences on the fluxes of carbon, metals and specific organic contaminants, and it resembles some properties of conventional petroleum-based microplastics.

Microplastics in commercial bivalves from coastal areas of Thailand and health risk associated with microplastics in ingested bivalves

Microplastics (MPs) contamination in marine organisms is a significant threat to seafood consumers worldwide. This study is the first to investigate the abundance of MPs in the commercial bivalves from six sites along Thailand's coastline, the daily exposure of bivalve consumers to MPs, and potential associated health risks. The microplastic occurrence varied from 69 % to 93 % in four bivalve species while the average abundance of MPs was 1.87 ± 0.86 items/individual or 0.46 ± 0.43 items/g ww. Benthic bivalves (cockles and clams) contained more MPs than their pelagic counterparts (mussels and oysters). Small blue microfibers (<500 μm) were the most abundant. The most common polymers were natural based polymers (cotton and rayon) and polyethylene terephthalate (PET). The daily microplastic exposure for consumers was 0.52 items/person. Although the risk of microplastic contamination is low, we recommend investigation into the transfer of MPs within the food web, notably as it may pose significant human health concerns.

The potential influence of microplastics on the microbiome and disease susceptibility in sea turtles

Microplastics (MPs) are particles with sizes of ≤5 mm formed when plastic materials break down. These contaminants are often found in marine environments, making it easy for sea turtles to ingest them and for their microbiome to be exposed. MPs can disrupt microbiome balance, leading to dysbiosis and making organisms more susceptible to diseases. Owing to the significance of these processes, it is crucial to dedicate research to studying the metabolic and genetic analysis of the gut microbiome in sea turtles. The objective of this study was to describe the effects of exposure to MPs on the gut microbiome of sea turtles, based on current knowledge. This review also aimed to explore the potential link between MP exposure and disease susceptibility in these animals. We show that the metabolites produced by the gut microbiome, such as short-chain fatty acids (SCFAs), polyamines, and polysaccharide A, can regulate the expression of host genes. Regulation occurs through various mechanisms, including histone acetylation, DNA methylation, and the modulation of cytokine gene expression. These processes are essential for preserving the integrity of the gut mucosa and enhancing the functionality of immune cells. Exposure to MPs disrupts the gut microbiome and alters gene expression, leading to immune system disturbances in sea turtles. This vulnerability makes turtles more susceptible to opportunistic microorganisms such as chelonid alphaherpesvirus 5 (ChAHV5), which is linked to the development of fibropapillomatosis (FP). Additionally, targeted dietary interventions or the use of live microorganisms such as probiotics can help restore microbial biodiversity and recover lost metabolic pathways. The goal of these interventions is to restore the functionality of the immune system in sea turtles undergoing rehabilitation at specialized centers. The gut microbiome plays a crucial role in sea turtle health, sparking discussions and investigations that can potentially lead to promising treatments for these animals.

Health Implications of Widespread Micro- and Nanoplastic Exposure: Environmental Prevalence, Mechanisms, and Biological Impact on Humans

The increasing awareness of the potential health risks associated with microplastics' (MPs) and nanoplastics' (NPs) presence in the environment has led to a significant rise in research focused on these particles over the past few years. This review focuses on the research on MPs'/NPs' presence and spread, pathways of exposure, toxicological effects on human health and legal framework related to MP/NP challenges. Several research projects have aimed to assess their potential harm to human health, focusing on different systems and organs. After exposure (independent of the pathway), these hazards reach the blood stream and concentrate in different organs. Further, they are responsible for harmful changes, having an immediate effect (pain, inflammation, or hormone imbalance) or lead to a long-term disease (e.g., infertility, chronic obstructive pulmonary disease, or cancer). Toxicological effects have been noticed at high concentrations of MPs, specifically polystyrene, the most widespread typical MP, but only short-term effects have been mostly studied. Significant quantities of consumed MPs have been discovered to have diverse detrimental effects, posing a threat to human welfare. The exact concentrations of microplastics that are inhaled and swallowed and then build up in the human body are still not known. Further investigation is necessary to evaluate the impact of MP/NP contamination at minimal concentrations and for prolonged durations.

Innovative biomaterials for food packaging: Unlocking the potential of polyhydroxyalkanoate (PHA) biopolymers

Polyhydroxyalkanoate (PHA) biopolyesters show a good balance between sustainability and performance, making them a competitive alternative to conventional plastics for ecofriendly food packaging. With an emphasis on developments over the last decade (2014-2024), this review examines the revolutionary potential of PHAs as a sustainable food packaging material option. It also delves into the current state of commercial development, competitiveness, and the carbon footprint associated with PHA-based products. First, a critical examination of the challenges experienced by PHAs in terms of food packaging requirements is undertaken, followed by an assessment of contemporary strategies addressing permeability, mechanical properties, and processing considerations. The various PHA packaging end-of-life options, including a comprehensive overview of the environmental impact and potential solutions will also be discussed. Finally, conclusions and future perspectives are elucidated with a view of prospecting PHAs as future green materials, with a blend of performance and sustainability of food packaging solutions.

Elaborating more realistic model microplastics by simulating polypropylene's environmental ageing

In this work, we propose a new protocol for producing model microplastics from an industrial polymer and compare it to a conventional method, cryomilling. Polypropylene industrial pellets were chosen due to their widespread production and frequent presence in the environment, making them a notable source of microplastics. Both protocols start with aging under Ultra-Violet light of the pellets but differ in the subsequent mechanical stress applied-strong vs. soft-to break down the photodegraded pellets into microplastics. All generated particles were fully characterized in terms of size, shape, oxidation rate, and stability in aqueous media. Microplastics produced via cryomilling exhibited significant size and oxidation heterogeneity and tended to aggregate in water. Although the new protocol involving soft mechanical stress required a longer preparation time, it simulated more accurately the environmental degradation of raw plastic. This method successfully produced oxidized microplastics with a controlled size distribution centered around 50 µm which remained stable in water without stabilizers.

Embracing Nature's Clockwork: Crafting Plastics for Degradation in Plant Agricultural Systems

In the 21st century, global agriculture confronts the urgent challenge of increasing food production by 70% by 2050 while simultaneously addressing environmental and health concerns. Plastics, integral to agricultural innovation, present sustainability challenges due to their non-biodegradable nature and contribution to pollution. This perspective examines the transition to bioplastics, emphasizing their bio-based origin and their crucial characteristic of being readily biodegradable in the soil. Key bioplastics such as poly(lactic acid) (PLA), polyhydroxyalkanoates (PHAs), and biomass-derived polymers are discussed, particularly regarding the microplastic generation in soil resulting from their use in specific applications like mulch films, delivery systems, and soil conditioners. Embracing bioplastics signifies a significant step forward in achieving sustainable agriculture and addressing plastic waste. However, it is highlighted that while some bioplastics can be recovered and recycled, special applications where the plastic is in intimate contact with soil pose challenges for recovery. In these cases, that represent more than the 50% of plastics used in agriculture, meticulous design for biodegradation in soil synchronized with agricultural cycles is necessary. This approach ensures minimal environmental impact and promotes a circular approach to plastic use in agriculture.

Concentration, characterization, and risk assessment of microplastics in two main rivers in Birnin Kebbi, Nigeria

Background: Dukku and Kalgo rivers in Kebbi, Nigeria, provide essential ecosystem services such as drinking and domestic water, fishing, and farming. However, the safety of these rivers in terms of microplastic pollution has not been investigated. This study aimed to characterize and determine the concentration and associated risks of microplastics in both rivers. Methods: Microplastics were extracted from water samples through filtration and analyzed using spectroscopy and microscopy. Results: Significant concentrations of microplastics were detected in both rivers. Dukku River samples showed concentrations ranging from 125.00 to 160.30 particles/liter, while Kalgo River ranged from 119.30 to 134.70 particles/liter. Both rivers predominantly contained microplastic fibers and fragments, with fibers comprising the highest percentages (61% in the Dukku River and 56% in the Kalgo River). Microplastics in Kalgo River were predominantly sized between 0 and 100 µm, whereas in Dukku River, sizes ranged from 500 to 1000 µm. Polyamide was the dominant polymer, constituting 50% in the Dukku River and 42.50% in the Kalgo River, followed by polyethylene (34% in the Kalgo River and 25.60% in Dukku River), and polyvinyl alcohol (24.40% in Dukku River and 23.50% in Kalgo River). The predominant risk level posed by these polymers was level III (moderate risk), although polyamide posed a level IV risk (high risk). The pollution load index (PLI) for both rivers exceeded one, indicating a high risk. Conclusion: Microplastic pollution in these rivers poses ecological and health risks. Identifying and mitigating sources of microplastic entry into the rivers is crucial to reducing exposure levels.

Microplastics in marine ecosystems: A comprehensive review of biological and ecological implications and its mitigation approach using nanotechnology for the sustainable environment

Microplastic contamination has rapidly become a serious environmental issue, threatening marine ecosystems and human health. This review aims to not only understand the distribution, impacts, and transfer mechanisms of microplastic contamination but also to explore potential solutions for mitigating its widespread impact. This review encompasses the categorisation, origins, and worldwide prevalence of microplastics and methodically navigates the complicated structure of microplastics. Understanding the sources of minute plastic particles infiltrating water bodies worldwide is critical for successful removal. The presence and accumulation of microplastics has far reaching negative impacts on various marine creatures, eventually extending its implications to human health. Microplastics are known to affect the metabolic activities and the survival of microbial communities, phytoplankton, zooplankton, and fauna present in marine environments. Moreover, these microplastics cause developmental abnormalities, endocrine disruption, and several metabolic disorders in humans. These microplastics accumulates in aquatic environments through trophic transfer mechanisms and biomagnification, thereby disrupting the delicate balance of these ecosystems. The review also addresses the tactics for minimising the widespread impact of microplastics by suggesting practical alternatives. These include increasing public awareness, fostering international cooperation, developing novel cleanup solutions, and encouraging the use of environment-friendly materials. In conclusion, this review examines the sources and prevalence of microplastic contamination in marine environment, its impacts on living organisms and ecosystems. It also proposes various sustainable strategies to mitigate the problem of microplastics pollution. Also, the current challenges associated with the mitigation of these pollutants have been discussed and addressing these challenges require immediate and collective action for restoring the balance in marine ecosystems.

Unseen riverine risk: Spatio-temporal shifts of microplastic pollution and its bioavailability in freshwater fish within the Ikopa River urban system

Growing concern over microplastic pollution, driven by their widespread accumulation in the environment, stresses the need for comprehensive assessments. This study investigates the spatial and temporal distribution of microplastics in the Ikopa River (Antananarivo - Madagascar), which flows through a densely populated area, and examines their correlation with contamination levels in local fish species. By analyzing upstream and downstream stations across wet and dry seasons, only a notable increase in microplastic concentration downstream during the wet season was observed, ranging from 138.6 ± 9.0 to 222.0 ± 24.5 particles m-3, with polyethylene-co-vinyl acetate being the predominant polymer at 62.3 ± 5.13% of the total sampled polymers. This distribution underlines the impact of urban activities on pollution levels. Fish species, gambusia and Nile tilapia, were assessed for microplastic occurrence in gills and gastrointestinal tracts. Higher contamination rates were found in gambusia, enlightening the influence of feeding behaviour and fish habitat on microplastics contamination. Ingestion of microplastics directly from the water column was evident in both species, with the detection of high-density plastics such as polytetrafluoroethylene and polyvinyl chloride suggesting likely sediment contamination. This research highlights the widespread contamination of aquatic environments and its direct impact on local wildlife, pointing to a clear requirement for effective pollution management strategies.

Exposure to polyethylene microplastics exacerbate inflammatory bowel disease tightly associated with intestinal gut microflora

Polyethylene microplastics (PE MPs) have sparked widespread concern about their possible health implications because of their abundance, pervasiveness in the environment and in our daily life. Multiple investigations have shown that a high dosage of PE MPs may adversely impact gastrointestinal health. In tandem with the rising prevalence of Inflammatory bowel disease (IBD) in recent decades, global plastic manufacturing has risen to more than 300 million tons per year, resulting in a build-up of plastic by-products such as PE MPs in our surroundings. We have explored current advancements in the effect PE MPs on IBD in this review. Furthermore, we compared and summarized the detrimental roles of PE MPs in gut microbiota of different organisms viz., earthworms, super worm's larvae, yellow mealworms, brine shrimp, spring tails, tilapia, gilt-head bream, crucian carp, zebrafish, juvenile yellow perch, European sea bass, c57BL/6 mice and human. According to this review, PE MPs played a significant role in decreasing the diversity of gut microbiota of above-mentioned species which leads to the development of IBD and causes severe intestinal inflammation. Finally, we pinpoint significant scientific gaps, such as the movement of such hazardous PE MPs and the accompanying microbial ecosystems and propose prospective research directions.

Microplastics as a Threat to Aquatic Ecosystems and Human Health

The threat posed by microplastics has become one of the world's most serious problems. Recent reports indicate that the presence of microplastics has been documented not only in coastal areas and beaches, but also in water reservoirs, from which they enter the bodies of aquatic animals and humans. Microplastics can also bioaccumulate contaminants that lead to serious damage to aquatic ecosystems. The lack of comprehensive data makes it challenging to ascertain the potential consequences of acute and chronic exposure, particularly for future generations. It is crucial to acknowledge that there is still a substantial need for rapid and effective techniques to identify microplastic particles for precise evaluation. Additionally, implementing legal regulations, limiting plastic production, and developing biodegradation methods are promising solutions, the implementation of which could limit the spread of toxic microplastics.

Micro(nano)plastics from synthetic oligomers persisting in Mediterranean seawater: Comprehensive NMR analysis, concerns and origins

The presence in seawater of low-molecular-weight polyethylene (PE) and polydimethylsiloxane (PDMS), synthetic polymers with high chemical resistance, has been demonstrated in this study for the first time by developing a novel methodology for their recovery and quantification from surface seawater. These synthetic polymer debris (SPD) with very low molecular weights and sizes in the nano- and micro-metre range have escaped conventional analytical methods. SPD have been easily recovered from water samples (2 L) through filtration with a nitrocellulose membrane filter with a pore size of 0.45 μm. Dissolving the filter in acetone allowed the isolation of the particulates by centrifugation followed by drying. The isolated SPD were analysed by 1H nuclear magnetic resonance spectroscopy (1H NMR), identifying PE and PDMS. These polymers are thus persisting on seawater because of their low density and the ponderal concentrations were quantified in mg/m3. This method was used in an actual case study in which 120 surface seawater samples were collected during two sampling campaigns in the Mediterranean Sea (from the Gulf of Salerno to the Gulf of Policastro in South Italy). The developed analytical protocol allowed achieving unprecedented simplicity, rapidity and sensitivity. The 1H and 13C NMR structural analysis of the PE debris indicates the presence of oxidised polymer chains with very low molecular weights. Additionally, the origin of those low molecular weight polymers was investigated by analysing influents and effluents from a wastewater treatment plant (WWTP) in Salerno as a hot spot for the release of SPD: the analysis indicates the presence of low molecular weight polymers compatible with wax-PE, widely used for coating applications, food industry, cosmetics and detergents. Moreover, the origin of PDMS debris found in surface seawater can be ascribed to silicone-based antifoamers and emulsifiers.

Surface enhanced raman spectroscopy based sensitive and onsite detection of microplastics in water utilizing silver nanoparticles and nanodendrites

Plastics, of the order of microns in size, being not visible to the naked eye, are one of the significant contributors to pollution in the environment. Thus, the detection of micron-sized plastics (microplastics (MPs)) is crucial because of its hazardous toxic effects on our surroundings. In this work, we have proposed a quick and on-site detection of MPs, such as, polyvinyl chloride (PVC), polyvinyl alcohol (PVA) and polystyrene (PS) at ultra trace level using surface-enhanced Raman spectroscopy (SERS). To detect and analyse the spectra, two different nanostructures, such as, spherical shaped Ag nanoparticles (NPs), and shape anisotropic Ag nano-dendrites (NDs) were utilised to acquire the SERS spectra. A comprehensive analysis was further performed to check and investigate the amount of enhancements due to the mentioned nanostructures. We observed the Ag NDs exhibited amplified signal intensity compared to the Ag NPs due to the shape anisotropy leading to the surface charge confinement effect to create highly dense hotspots. However, the spherical shaped polystyrene beads of micron size exhibited better enhancement in Raman signal intensity when mixed with Ag NPs due to increased surface adsorption with the NPs. Therefore, the comparative study emphasizes the ability of using solution-based nanostructure as SERS for the onsite detection of microplastics having diverge size range at low concentration.

Occurrence and abundance of microplastics in surface water of Songkhla Lagoon

Background

Microplastic (MP) pollution is now a global critical issue and has been the subject of considerable worry for multiple various types of habitats, notably in lagoons which are coastal areas connected to the ocean. MPs are of concern, particularly because floating MP in surface water can be ingested by a number of marine organisms. There are several lagoons along Southeast Asia's coastline, but Songkhla Lagoon is Thailand's only exit with a rich biodiversity. To date, there has been little research undertaken on MP in this lagoon, so there is a pressing need to learn more about the presence of MP in the lagoon's water.

Methods

We investigate MPs in the surface water of Songkhla Lagoon, Thailand. Sampling took place at ten stations in the lagoon during the wet season in December 2022 and the dry season in February 2023. Samples were digested with hydrogen peroxide to remove organic matter followed by density separation using saturated sodium chloride. MPs were visually examined under a stereo microscope to describe and determine the shape, size, and color. Polymer type was identified using a micro Fourier transform infrared (FTIR) spectrometer. Moreover, the in-situ of water quality of the surface water was measured using a multi-parameter probe. A Mann-Whitney U test was performed to investigate the variations in MP levels and water quality parameters between the wet and dry seasons. Correlation analysis (Spearman rho) was used to determine the significance of correlations between MP and water quality (p < 0.05).

Results

MPs were detected at all ten of the sites sampled. The most abundant MPs were small size class (<500 µm, primarily consisting of fibers). Five types of polymers were seen in surface water, including polyethylene terephthalate, rayon, polypropylene, polyester, and poly (ethylene:propylene). Rayon and polyester were the dominant polymers. Additionally, the most dominant color of MPs in the wet and dry season was black and blue, respectively. The mean contents of MPs in the wet and dry season were 0.43 ± 0.18 and 0.34 ± 0.08 items/L, respectively. The Mann-Whitney U test suggested a significant difference between water quality in the wet and dry seasons (p < 0.05). Correlation analysis (Spearman rho) indicated a negative significant difference relationship between the MPs and the values of total dissolved solid (TDS) in the wet season (r = -0.821, p = <0.05), revealing that the large amounts of MPs may possibly be dispersed within surface water bodies with low TDS concentrations. Based on the overall findings, MP pollution in the surface water of the lagoon is not found to be influenced by the seasonal context. Rivers flowing into the lagoon, especially the U-Taphao River, may be a principal pathway contributing to increased MP pollution loading in the lagoon. The results can be used as baseline data to undertake further research work relevant to sources, fates, distribution, and impacts of MPs in other coastal lagoons.

Health benefits and health risks of contaminated fish consumption: Current research outputs, research approaches, and perspectives

Background

Fish contains high-quality omega-3 fatty acids, protein, vitamins, and minerals and due to this it is termed as an essential component of a balanced diet. But there have been concerns raised about the risks of consuming fish that is contaminated with toxins such as methylmercury, polychlorinated biphenyls (PCBs), dioxins, pesticides, and plastic waste. Consumption of contaminated fish containing these pollutants is raising global mortality and morbidity rates.

Scope and approaches

The review examines the current research outputs on the health benefits and potential health risks of fish consumption. The review also discusses various approaches to mitigating the health problems caused by fish consumption, highlights the roles of balancing the risks and benefits when consuming fish.

Key findings and conclusion

Different findings indicated that contaminants cause cancer, kidney failure, adverse neurological effect, cardiovascular diseases, and so on to vulnerable groups such as pregnant, child breast-feeding and children. In conclusion, there is a need to get more tangible evidence about the advantages and disadvantages of fish consumption to safeguard the wellbeing of the society.

A comparative study of in vivo toxicity in zebrafish embryos synthesized CuO nanoparticles characterized from Salacia reticulata

The Salacia reticulata, a medicinal woody climbing shrub, was utilized for our study, the green synthesis of CuO nanoparticles, which were analyzed through SEM, EDX, FTIR, XRD, and UV‒Vis spectroscopy. This study assessed the toxicity to zebrafish embryos and explored the antibacterial, cytotoxic, antidiabetic, and anti-inflammatory properties of the synthesized nanoparticles. In results, the UV absorption of the CuO NPs showed that the intensity of nanoparticle green colloidal suspension changed from blue to green, which also confirmed that the spectrum of the green CuO NPs changed from colorless to black. in FT-IR and XRD spectral analysis to identify functional groups and determine the particle size of CuO NPs prepared by green and chemical methods. Its showed that CuO NPs (green) had a size of approximately 42.2 nm, while CuO NPs (chemical) had a size of approximately 84 nm. The morphology of these NPs was analyzed using SEM-EDX. Compared with their chemically prepared counterparts, the green-synthesized CuO nanoparticles demonstrated superior dispersion. Additionally, both green and chemical CuO nanoparticles at a concentration of 200 µL/mL caused developmental anomalies and increased mortality in zebrafish embryos and larvae. The green and chemical CuO NPs inhibited α-glucosidase enzyme activity at concentrations between 10 and 50 µL/mL, with IC50 values of 22 µL/mL and 26 µL/mL, respectively. The extract exhibited anti-inflammatory activity, with IC50 values of 274 and 109 µL/mL. The authors concluded that this green nanoparticle method has potential as a more eco-friendly and cost-effective alternative to traditional synthetic methods. NPs are widely used in human contact fields (medicine and agriculture), hence synthesis methods that do not involve toxic substances are becoming increasingly important.

Tricks and tracks of prevalence, occurrences, treatment technologies, and challenges of mixtures of emerging contaminants in the environment: With special emphasis on microplastic

This paper aims to emphasize the occurrence of various emerging contaminant (EC) mixtures in natural ecosystems and highlights the primary concern arising from the unregulated release into soil and water, along with their impacts on human health. Emerging contaminant mixtures, including pharmaceuticals, personal care products, dioxins, polychlorinated biphenyls, pesticides, antibiotics, biocides, surfactants, phthalates, enteric viruses, and microplastics (MPs), are considered toxic contaminants with grave implications. MPs play a crucial role in transporting pollutants to aquatic and terrestrial ecosystems as they interact with the various components of the soil and water environments. This review summarizes that major emerging contaminants (ECs), like trimethoprim, diclofenac, sulfamethoxazole, and 17α-Ethinylestradiol, pose serious threats to public health and contribute to antimicrobial resistance. In addressing human health concerns and remediation techniques, this review critically evaluates conventional methods for removing ECs from complex matrices. The diverse physiochemical properties of surrounding environments facilitate the partitioning of ECs into sediments and other organic phases, resulting in carcinogenic, teratogenic, and estrogenic effects through active catalytic interactions and mechanisms mediated by aryl hydrocarbon receptors. The proactive toxicity of ECs mixture complexation and, in part, the yet-to-be-identified environmental mixtures of ECs represent a blind spot in current literature, necessitating conceptual frameworks for assessing the toxicity and risks with individual components and mixtures. Lastly, this review concludes with an in-depth exploration of future scopes, knowledge gaps, and challenges, emphasizing the need for a concerted effort in managing ECs and other organic pollutants.

Severe microplastic pollution risks in urban freshwater system post-landfill fire: A case study from Brahmapuram, India

To investigate the escalating issue of microplastic (MP), pollution in urban water bodies, this study focuses on the aftermath of the Brahmapuram landfill fire in Kochi, India, analyzing its impact on MP concentrations in nearby freshwater system. The study conducted sampling sessions at the landfill site immediately before and after the fire. Post-fire, findings demonstrated a substantial increase in MP concentrations in surface waters, with levels rising from an average 25793.33 to 44863.33 particles/m³, featuring a notable presence of larger, predominantly black MPs. Sediment samples showed no significant change in MP count, but there was a significant increase in mass concentration. SEM/EDS analysis revealed changes in surface morphology and elemental composition, suggesting thermal degradation. Risk assessment using the Microplastic Pollution Index (MPI) and Risk Quotient (RQ) methods indicated heightened MP pollution risk in surface water post-fire. Hierarchical cluster analysis revealed the landfill's proximity as a significant factor influencing MP characteristics in the aquatic system. The study highlights the escalated challenge of MP pollution in urban water bodies following environmental disasters like landfill fires, underscoring the urgent need for policy and environmental management strategies.

Synthesis and Isolation of Phenol- and Thiol-Derived Epicatechin Adducts Prepared from Avocado Peel Procyanidins Using Centrifugal Partition Chromatography and the Evaluation of Their Antimicrobial and Antioxidant Activity

Polyphenols from agro-food waste represent a valuable source of bioactive molecules that can be recovered to be used for their functional properties. Another option is to use them as starting material to generate molecules with new and better properties through semi-synthesis. A proanthocyanidin-rich (PACs) extract from avocado peels was used to prepare several semi-synthetic derivatives of epicatechin by acid cleavage in the presence of phenol and thiol nucleophiles. The adducts formed by this reaction were successfully purified using one-step centrifugal partition chromatography (CPC) and identified by chromatographic and spectroscopic methods. The nine derivatives showed a concentration-dependent free radical scavenging activity in the DPPH assay. All compounds were also tested against a panel of pathogenic bacterial strains formed by Listeria monocytogenes (ATCC 7644 and 19115), Staphylococcus aureus (ATCC 9144), Escherichia coli (ATCC 11775 and 25922), and Salmonella enterica (ATCC 13076). In addition, adducts were tested against two no-pathogenic strains, Limosilactobacillus fermentum UCO-979C and Lacticaseibacillus rhamnosus UCO-25A. Overall, thiol-derived adducts displayed antimicrobial properties and, in some specific cases, inhibited biofilm formation, particularly in Listeria monocytogenes (ATCC 7644). Interestingly, phenolic adducts were inactive against all the strains and could not inhibit its biofilm formation. Moreover, depending on the structure, in specific cases, biofilm formation was strongly promoted. These findings contribute to demonstrating that CPC is a powerful tool to isolate new semi-synthetic molecules using avocado peels as starting material for PACc extraction. These compounds represent new lead molecules with antioxidant and antimicrobial activity.