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The accumulation of microplastics in various ecosystems has now been well documented and recent evidence suggests detrimental effects on various biological processes due to this pollution. Accumulation of microplastics in the natural environment is ultimately due to the chemical nature of widely used petroleum-based plastic polymers, which typically are inaccessible to biological processing. One way to mitigate this crisis is adoption of plastics that biodegrade if released into natural environments. In this work, we generated microplastic particles from a bio-based, biodegradable thermoplastic polyurethane (TPU-FC1) and demonstrated their rapid biodegradation via direct visualization and respirometry. Furthermore, we isolated multiple bacterial strains capable of using TPU-FC1 as a sole carbon source and characterized their depolymerization products. To visualize biodegradation of TPU materials as real-world products, we generated TPU-coated cotton fabric and an injection molded phone case and documented biodegradation by direct visualization and scanning electron microscopy (SEM), both of which indicated clear structural degradation of these materials and significant biofilm formation.

There have been major advances in the science to predict the likely environmental concentrations of nanomaterials, which is a key component of exposure and subsequent risk assessment. Considerable progress has been since the first Material Flow Analyses (MFAs) in 2008, which were based on very limited information, to more refined current tools that take into account engineered nanoparticle (ENP) size distribution, form, dynamic release, and better-informed release factors. These MFAs provide input for all environmental fate models (EFMs), that generate estimates of particle flows and concentrations in various environmental compartments. While MFA models provide valuable information on the magnitude of ENP release, they do not account for fate processes, such as homo- and heteroaggregation, transformations, dissolution, or corona formation. EFMs account for these processes in differing degrees. EFMs can be divided into multimedia compartment models (e.g., atmosphere, waterbodies and their sediments, soils in various landuses), of which there are currently a handful with varying degrees of complexity and process representation, and spatially-resolved watershed models which focus on the water and sediment compartments. Multimedia models have particular applications for considering predicted environmental concentrations (PECs) in particular regions, or for developing generic "fate factors" (i.e., overall persistence in a given compartment) for life-cycle assessment. Watershed models can track transport and eventual fate of emissions into a flowing river, from multiple sources along the waterway course, providing spatially and temporally resolved PECs. Both types of EFMs can be run with either continuous sources of emissions and environmental conditions, or with dynamic emissions (e.g., temporally varying for example as a new nanomaterial is introduced to the market, or with seasonal applications), to better understand the situations that may lead to peak PECs that are more likely to result in exceedance of a toxicological threshold. In addition, bioaccumulation models have been developed to predict the internal concentrations that may accumulate in exposed organisms, based on the PECs from EFMs. The main challenge for MFA and EFMs is a full validation against observed data. To date there have been no field studies that can provide the kind of dataset(s) needed for a true validation of the PECs. While EFMs have been evaluated against a few observations in a small number of locations, with results that indicate they are in the right order of magnitude, there is a great need for field data. Another major challenge is the input data for the MFAs, which depend on market data to estimate the production of ENPs. The current information has major gaps and large uncertainties. There is also a lack of robust analytical techniques for quantifying ENP properties in complex matrices; machine learning may be able to fill this gap. Nevertheless, there has been major progress in the tools for generating PECs. With the emergence of nano- and microplastics as a leading environmental concern, some EFMs have been adapted to these materials. However, caution is needed, since most nano- and microplastics are not engineered, therefore their characteristics are difficult to generalize, and there are new fate and transport processes to consider.

[Display omitted] • Larvae of Hermetia illucens regularly develop on PVC-MPs-supplemented diet. • PVC-MPs are ingested by the larvae and reduced in their size. • Midgut morphology is not affected by PVC-MPs in the larval diet. • PVC-MPs in the larval diet do not affect microbial alpha- and beta-diversity. • PVC-MPs selectively affect the abundances of gut bacterial and fungal taxa. In a world with a population exceeding 8 billion people and continuing to grow, pollution from food and plastic waste is causing long-term issues in ecosystems. Potential solutions may be found by exploiting insect-based bioconversion. In this context, we investigated the impact of polyvinyl chloride microparticles (PVC-MPs) on the development of Hermetia illucens (black soldier fly; BSF) and its midgut bacterial and fungal microbiota. The impact of PVC-MPs was evaluated feeding BSF larvae with a PVC-MPs-supplemented diet. The larvae exposed to different PVC-MPs concentrations (2.5%, 5%, 10% and 20% w/w) developed into adults with no significant increase in pupal mortality. Faster development and smaller pupae were observed when 20% PVC-MPs was provided. The BSF larvae ingest PVC-MPs, resulting in a reduction in MPs size. Larvae exposed to PVC-MPs did not exhibit differences in gut morphology. Regarding the impact of PVC-MPs on the structure of both bacterial and fungal communities, the overall alpha- and beta-diversity did not exhibit significant changes. However, the presence of PVC-MPs significantly affected the relative abundances of Enterobacteriaceae and Paenibacillaceae among the bacteria and of Dipodascaceae and Plectospharellaceae among the fungi (including yeast and filamentous life forms), suggesting that PVC-MP contamination has a taxa-dependent impact. These results indicate that BSF larvae can tolerate PVC-MPs in their diet, supporting the potential use of these insects in organic waste management, even in the presence of high levels of PVC-MP contamination. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) in the air are one of the major concerns due to their possible health risks. In addition, airborne microplastics act as a carrier for several toxic air pollutants and cause carcinogenic, mutagenic and teratogenic effects. Nylon 66 is one of the most abundant MPs in the microenvironments. In this study, we report an optimized method for the quantification of nylon 66 MPs present in the fine particulate matter (PM2.5) using high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The optimized method exhibited excellent linearity, recovery rates, intraday and interday precision and sensitivity. The optimized method was deployed to carry out a pilot study to measure the mass concentrations of nylon 66 microplastics present in the inhalable fraction of particulate matter collected in a shopping complex. The observed mass concentrations of nylon 66 MPs in this study are in the range from 0.30 ng m−3 to 4.37 ng m−3. This study demonstrates the presence of inhalable fraction of nylon 66 MPs in the indoor environment and their mass concentrations were determined using HPLC-MS/MS. [ABSTRACT FROM AUTHOR]

Microplastic pollution in water samples from Kartepe Avluburun and Gebze Denizli drinking water treatment plants in Kocaeli, Turkey, was investigated for the first time. In Kartepe Avluburun, the particle abundance in raw, treated, and tap water samples ranged from 1579 to 5283 (mean: 3117) particles per liter, 637.5 to 2274 (mean: 1317) particles per liter, and 758.5 to 2485 (mean: 1476.6) particles per liter, respectively; whereas these results for Gebze Denizli were 786.5–3388 (mean: 1882), 397.5–2226 (mean: 1028), and 470–2821 (mean: 1256.8). Similar microplastics removal efficiency was determined in both treatment plants at all seasons except spring. In fall season, a peak removal efficiency of 76.3% was achieved. The prevalent polymer types of microplastics in the raw water were polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, and polyamide. The most common microplastic sizes in the samples were between 1 and 20 μm (82%), the color was blue, and the shape was fragment type. [ABSTRACT FROM AUTHOR]

Rampant industrialization has led to widespread reliance on hydrocarbon polymers for various commercial applications. While these synthetic polymers, commonly known as plastics, degrade in slowly in the environments, the toxic effects of their micro-sized particles remain underexplored. In this study, we synthesized polyisobutylene (PIB) microparticles in the lab and evaluated their toxicity and accumulation in a zebrafish model. Pristine and fluorescent PIB-microplastics (MPs), with particle sizes ranging from 2 to 10 μm, were synthesized using the solvent evaporation method. Fourier-transform infrared spectroscopy (FTIR) confirmed the stability of the suspensions. Zebrafish larvae exposed to various concentrations of PIB-MPs exhibited numerous morphological and molecular changes, including delayed hatching, impaired swimming behavior, increased reactive oxygen species levels, altered mRNA levels of genes encoding antioxidant proteins, and reduced survival rates. Dissections revealed PIB-MP accumulation in the guts of larvae and adult fish within 7–21 days, causing damage to the intestinal mucosa. These findings provide insights into how contaminants like PIB can induce pathophysiological defects in aquatic fauna and pose potential health hazards to humans. [ABSTRACT FROM AUTHOR]

In the last century, human activities were the primary cause of air, water, and soil contamination. However, in the twenty-first century, while pollutants like sulfur oxides (SOx) and nitrogen oxides (NOx) remain significant, microplastics (MPs) have emerged as a new global environmental concern. Microplastics are plastic fragments that are less than 5 mm in diameter. Their widespread distribution in aquatic and terrestrial ecosystems has adverse impacts on various ecological systems. The presence of MPs has been well documented in diverse matrices, such as table salt, drinking water, indoor and outdoor air, beer, cold drinks, aquatic organisms, plants, and earthworms. The potential adverse effects of MPs consumption have been reported in various organisms, including earthworms and aquatic fishes; however, their potential effects on human health through respiratory, dietary, and other exposures are still being elucidated. This review provides a comprehensive overview of the current knowledge on potential sources, quantities present in water, table salt, air, and possible routes in the human body through different trophic levels. Furthermore, this paper reviews insights into the movement and accumulation of MPs at different trophic levels (i.e., aquatic, and terrestrial organisms) and their impacts on the cycling of soil carbon and nutrients (nitrogen and phosphorus). Additionally, this review paper addresses the current trends in MPs research and proposes strategic management techniques to mitigate MPs pollution. [ABSTRACT FROM AUTHOR]

Microplastic degradation by bacteria can degrade low-density polyethylene (LDPE). This study aimed to analyze the potential of Ambon Bay bacteria for microplastic degradation, the condition of microplastics after degradation, and identification of the potential for microplastic degradation. The results of isolation revealed as many as 20 bacterial isolates, which correlated with physicochemical conditions in the waters of Ambon Bay. Nine of them could degrade microplastics as indicated by the presence of a clear zone, namely KA1, KA2, KA3, KA4, KA5, KA9, KA10, KS6, and KS8. They were checked for biofilm formation, microplastic hydrophobicity, and percentage of microplastic weight reduction. Four isolates with the highest percentage of microplastic weight reduction on day 40 were KA1, KA2, KA3, and KA10 at 36.19%, 10.16%, 28.39%, and 17.07%, respectively. The results of LDPE microplastic degradation showed differences using field emission scanning electron microscopy-energy dispersive spectroscopy (FESEM/EDS), attenuated total reflection-fourier transform infrared (ATRFTIR), and X-ray diffraction (XRD). The bacterial isolates identified were KA1 (Bacillus cereus), KA2 (Bacillus toyonesis), KA3 (Bacillus paramycoides), and KA10 (Escherichia coli). Indigenous bacteria from the waters of Ambon Bay have the potential to degrade LDPE microplastics, which causes structural changes, decreased crystallinity, weight, and C=C groups in microplastics after degradation, with bacterial isolate KA1 identified as Bacillus cereus showing the best potential with degradation of LDPE microplastics by 36.19%. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are ubiquitous in terrestrial and marine environments. This research work studied the occurrence, distribution of MPs and heavy metals associated with these MPs in soils of different land- use types viz. residential, commercial, and industrial areas. We identified 15 types of MP polymers, of which polypropylene (15.51%), polyethylene (12.28%), polyamide (9.57%) were dominant. MPs abundance ranged from 8.54 × 104 to 8.51 × 105 particles/kg of soil. Average abundance of MPs in the three fractions viz. < 1 mm, 1–2 mm, and 2–5 mm were 1.85 × 105, 1.31 × 105, and 697.5 particles/kg of soil, respectively. Among the three land use types, MPs abundance in < 1 mm and 1–2 mm soil fractions were significantly higher in residential areas than that in commercial and industrial areas, i.e. <1 mm: 3.4 × 105, 1.26 × 104 and 9.0 × 104, and 1–2 mm: 2.35 × 105, 8.36 × 104, and 7.50 × 104 particles/kg, respectively, for residential, commercial and industrial areas respectively. The average concentration of Cr, Fe, Mn, Cd, Co, Ni, Cu and Pb in soils were 31.79, 11047.29, 423.92, 0.05, 11.86, 17.53, 125.95 and 28.29 mg/kg, respectively, whereas that in MPs were 6.27, 2181.64, 277.36, 0.24, 6.43, 8.29, 47.05 and 9.24 mg/kg, respectively. Concentration of Cd sorbed on MPs was higher than those found in soils. Also, Pb and Cd in MPs were positively correlated to MPs abundance, indicating MPs can be vectors of heavy metals in soils. The synergistic effect of MPs and heavy metals might put soil organisms at risk. [ABSTRACT FROM AUTHOR]

Fucoxanthin (FX) is a natural pigment that is found in brown seaweeds, diatoms, and other marine organisms. FX helps to improve the soil's physical and chemical properties. FX has been shown to have a positive impact on plant growth. The widespread usage and production of microplastics (MPs) products has resulted in a surge of plastic waste in the natural environment, posing a growing threat to plant growth. This study investigated the effects of Polystyrene MPs (PS) and FX on soil pH, electrical conductivity (EC), organic matter ;(OM), and available nutrients and maize (Zea mays L.) growth in a calcareous soil. Results showed PS led to a decline in soil pH, which negatively impacted maize growth. Higher levels of PS led to lower root and shoot dry weight, chlorophyll content, leaf area, and plant height. Increasing FX levels in the soil led to an increase in available nutrients, while decreasing EC and had a positive effect on maize growth factors, particularly under non-stress conditions. The positive effects of FX may be due to its antioxidant properties, ability to enhance photosynthesis, aid in nutrient absorption, and activate growth-related genes. FX mitigated the negative effects of PS on plant growth. The study highlights the potential of FX as a soil amendment to promote plant growth and mitigate the effects of environmental stressors on agriculture. [ABSTRACT FROM AUTHOR]

This study examines microplastic contamination in river macroinvertebrates and fish within a rapidly urbanising tropical catchment, and provides data on the quantity of microplastics ingested by various taxonomic and functional feeding groups.We employed both a widely used low‐resolution visual inspection method, capable of identifying microplastics ranging from 0.1 to 5 mm, and a novel automated method specifically designed to identify smaller plastics in the nano size range, from 0.004 to 0.1 mm.Analysis using the low‐resolution method indicated that a significant portion of fish (95%) and macroinvertebrates (44%) contained larger microplastics. The composition of microplastic within the animals differed from that in river water and on the river bed: microplastics in the water and on the bed were predominantly fibres (98% and 92% respectively), whereas the animals exhibited a more even mix of fibres (c. 35%), fragments (c. 43%), and film (c. 22%).Microplastic loads in aquatic organisms correlated with feeding group and body size, although patterns were not always consistent. Larger individuals generally contained more microplastic, especially among macroinvertebrates, but this trend was not observed uniformly among fish species. Additionally, differences in body loads among macroinvertebrate taxa and feeding groups varied depending on whether loads were expressed per individual or per unit weight.Use of the high‐resolution enumeration method revealed a substantially higher microplastic count compared to the low‐resolution method, highlighting the potential underestimation of contamination levels by the latter. The study underscores the non‐random uptake of microplastics by aquatic biota, influenced by feeding mode, and stresses the necessity of high‐resolution sample processing for accurate quantification of contamination levels and risk assessment for smaller organisms. [ABSTRACT FROM AUTHOR]

Microplastics have become a ubiquitous contaminant, but their fate in food animals is largely unknown. In this study, [14C]-polystyrene microplastic (PS-MP) particles were orally dosed to lactating sheep to evaluate their absorption and disposition. Elimination of the [14C]-PS-MP was predominately through faeces with faecal radioactivity peaking at 24 h post-dosing but continuing to be present throughout the entire 72 h study period. Only a small fraction (≤ 1%) of the dosed [14C]-PS-MP was present in blood, milk, and urine. Pharmacokinetic analysis of blood plasma radioactivity, using non-compartment modeling, indicated rapid absorption (T1/2 0.4 to 3 h) with slow elimination (T1/2 37 to 48 h). Radioactivity in milk and urine had similar elimination patterns with radiocarbon activities peaking 24 h post-dosing with detectable elimination throughout the 72 h study period. No radioactivity was quantifiable in tissues at the 72 h withdrawal period. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are one of the major substantial pollutants in the environment and are stored in sediments worldwide, especially in marine environments. This study shed light on the abundance, distribution, sources and chemical composition of MPs present in the surface sediments collected from the shelf part of the southeast coast of India, Bay of Bengal. A total of twenty-seven surface sediment samples were collected to study MPs pollution. The abundance and morphological characteristics of MPs were determined by counting using an Olympus SXZ7 stereo microscope. Raman spectroscopy analysis was used to identify the polymer type of the MPs. The average abundance of MPs in the study area is 460±275 MPs/kg in dry sediment. Regarding colour, transparent particles were predominant (46.42%), followed by blue, green, brown, etc. With respect to particle shape and size, fibres and 500-µm sized MPs are abundant. Polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), high-density polyethylene (HDPE), low-density polyethylene (LDPE) and polystyrene (PS) are the polymer types characterised in the study area. The higher abundance of MPs in the study area can be attenuated to human interruptions, viz., tourism, fishing and inappropriate sewage disposal in the marine environment. In addition to this, population density also plays an important role in providing MPs to the marine environment. This study provides the most valuable data to extrapolate the research for mitigating MP pollution in oceans. It also informs mankind about their disastrous activities on the marine environment, which is expected to recuperate quickly and negatively impact human health and the functionality of the marine system. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) have distributed in agricultural soil. However, the effects of MPs on the growth of tobacco remain unclear. In this study, a pot experiment was conducted to evaluate the effects of linear low-density polyethylene (LLDPE) MPs at four different concentrations (0 mg·kg-1 as control, 10 mg·kg-1, 100 mg·kg-1, and 1000 mg·kg-1) on soil enzyme activity, physiological characteristics, and tobacco growth. The results showed that compared with the control, the treatments of 100 and 1000 mg·kg-1 significantly inhibited the activities of soil catalase (S-CAT) and soil sucrase (S-SC). Compared with the control, the 1000 mg·kg-1 treatment significantly altered root morphology, inhibited tobacco growth, and water content, resulting in a significant decrease in chlorophyll a content, catalase (CAT) and superoxide dismutase (SOD) activities in tobacco leaves, thereby incited a significant increase in malondialdehyde (MDA) content and peroxidase (POD) activity. Interestingly, the 10 mg·kg-1 treatment stimulated the activity of soil urease (S-UE) and root biomass. Overall, this study highlights the significant impact of MPs on soil enzymes, oxidative damage to tobacco, and inhibition of tobacco growth and development. It emphasizes the environmental risks of MPs pollution in soil, particularly for commercial crops like tobacco, and provides insights for controlling MPs abundance in the environment. Further research is needed to investigate the underlying mechanisms of MPs' effects on metabolism and genes in the soil-tobacco-microbial system. [ABSTRACT FROM AUTHOR]

Both microplastics and antibiotics are commonly found contaminants in aquatic ecosystems. Microplastics have the ability to absorb antibiotic pollutants in water, but the specific adsorption behavior and mechanism are not fully understood, particularly in relation to the impact of microplastics on toxicity in aquatic environments. We review the interaction, mechanism, and transport of microplastics and antibiotics in water environments, with a focus on the main physical characteristics and environmental factors affecting adsorption behavior in water. We also analyze the effects of microplastic carriers on antibiotic transport and long‐distance transport in the water environment. The toxic effects of microplastics combined with antibiotics on aquatic organisms are systematically explained, as well as the effect of the adsorption behavior of microplastics on the spread of antibiotic resistance genes. Finally, the scientific knowledge gap and future research directions related to the interactions between microplastics and antibiotics in the water environment are summarized to provide basic information for preventing and treating environmental risks. Environ Toxicol Chem 2024;43:1950–1961. © 2024 SETAC [ABSTRACT FROM AUTHOR]

We examined the distribution characteristics of atmospheric microplastics in typical desert agricultural regions, with a focus on the agricultural areas surrounding the Taklamakan Desert, Xinjiang, China. We collected samples of total suspended particulate matter (TSP), atmospheric deposition, and atmospheric dust using both active and passive collection methods. The chemical composition, particle size, shape, and color of atmospheric microplastics were examined using a stereomicroscope and a Fourier‐transform infrared spectrometer to analyze their characteristics. The results showed that the primary chemical compositions of microplastics included polypropylene (PP), polyethylene, polyethylene terephthalate, polymethylmethacrylate, and cellophane. Particle sizes were mainly within the range of 0 to 1000 μm. Fibrous microplastics constituted the majority of the TSP and atmospheric deposition, whereas film‐like microplastics constituted the largest proportion of atmospheric dustfall. The deposition flux of atmospheric microplastics in the first quarter was measured at 103.21 ± 22.12 particles/m2/day, which was lower than that observed in conventional agricultural areas. The abundance of microplastics in atmospheric dustfall was found to be 1.36 particles/g. The proportion of PP microplastics in atmospheric dustfall can be as high as 35%. Through a comparison of microplastic content in TSP during dust storms and under normal weather conditions, it was found that dust storms can lead to an increase in the abundance of microplastics within the atmospheric TSP. The present study provides a scientific basis for understanding the distribution of atmospheric microplastics in typical desert agricultural regions. Environ Toxicol Chem 2024;43:1982–1995. © 2024 SETAC. [ABSTRACT FROM AUTHOR]

Tire and road wear particles (TRWP) contain complex mixtures of chemicals and release them to the environment, and potential toxic effects of these chemicals still need to be characterized. We used a standardized surrogate for TRWP, cryogenically milled tire tread (CMTT), to isolate and evaluate effects of tire‐associated chemicals. We examined organic chemical mixtures extracted and leached from CMTT for the toxicity endpoints genotoxicity, estrogenicity, and inhibition of bacterial luminescence. The bioassays were performed after chromatographic separation on high‐performance thin‐layer chromatography (HPTLC) plates. Extracts of CMTT were active in all three HPTLC bioassays with two estrogenic zones, two genotoxic zones, and two zones inhibiting bacterial luminescence. Extracts of CMTT artificially aged with thermooxidation were equally bioactive in each HPTLC bioassay. Two types of aqueous leachates of unaged CMTT, simulating either digestion by fish or contact with sediment and water, contained estrogenic chemicals and inhibitors of bacterial luminescence with similar profiles to those of CMTT extracts. Of 11 tested tire‐associated chemicals, two were estrogenic, three were genotoxic, and several inhibited bacterial luminescence. 1,3‐Diphenylguanidine, transformation products of N‐(1,3‐dimethylbutyl)‐N′‐phenyl‐p‐phenylenediamine, and benzothiazoles were especially implicated through comparison to HPTLC retention factors in the CMTT samples. Other bioactive bands in CMTT samples did not correspond to any target chemicals. Tire particles clearly contain and can leach complex mixtures of toxic chemicals to the environment. Although some known chemicals contribute to estrogenic, genotoxic, and antibacterial hazards, unidentified toxic chemicals are still present and deserve further investigation. Overall, our study expands the understanding of potential adverse effects from tire particles and helps improve the link between those effects and the responsible chemicals. Environ Toxicol Chem 2024;43:1962–1972. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Microplastics in the aquatic environment are susceptible to colonization by surrounding microorganisms, which form biofilms over the microplastic's surface. These biofilm‐laden microplastics can then interact with a diverse array of contaminants. In the present study, biofilms were grown on microplastics in a laboratory setting using Pseudomonas aeruginosa as a model biofilm‐forming bacterium for periods of 5 to 15 days. The sorption of three organic compounds representing different levels of hydrophobicity, namely methylene blue (MB), phenanthrol, and phenanthrene, was used to evaluate the effect of biofilm biomass on the adsorption of organic contaminants to microplastics. The sorption of MB and phenanthrol was found to increase with biofouling time, indicating affinity between these contaminants and the biofilm biomass on the particle. However, the presence of a biofilm did not influence the sorption of phenanthrene on the microplastics. These results suggest that the hydrophobicity of organic contaminants plays a major role in how biofouling of microplastics will influence contaminant sorption by microplastics. For some contaminants, biofilm can enhance the role of microplastics as contaminant vectors. These findings emphasize the need to understand the biomass load on environmental microplastics and the contaminants that associate with it for an accurate representation of the risk associated with microplastics in the environment. Environ Toxicol Chem 2024;43:1973–1981. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

There are major gaps in illustrating the risk to freshwater fish that are exposed to environmental microplastics (MPs), even though MPs in freshwater environments has drawn much concern. To explore the potentially negative effects of microplastics on freshwater fish, grass carp (averaging 9.215 ± 0.035g) were exposed to microplastics (32-40 μm in diameter) at two environmental concentrations (100 and 1000 μg/L) for 21 days, and evaluated for physio-biochemical performance, gut microbiome, and metabolome responses. After exposure, microplastics were detected in the intestine and within basal nuclei and goblet cells hyperplasia. Antioxidant enzyme activities (superoxide dismutase and catalase) also significantly decreased within the intestines (P < 0.05). Through 16S rRNA gene sequencing analysis, a decrease in diversity and richness was observed in the MPs-H and MPs-L groups. The abundance of opportunistic pathogens increased and beneficial bacteria decreased in both MP treatments. For example, Acinetobacter and Bosea proportions were higher in the MPs-L group, while Bacteroides and Shewanella increased in the MPs-H group. Furthermore, abundance of Lactobacillus decreased both in the MPs-H and MPs-L groups. Metabolomics analysis revealed primary bile acid biosynthesis metabolism upregulated in the MPs-L and purine metabolism downregulated in the MPs-H group. Additionally, an integration analysis of the gut microbiome and metabolomics identified significant associations between several bacteria taxa and metabolites related to intestinal repair. Taken together, these results highlighted the negative effects on intestinal morphology, oxidative stress, and microbiome and emphasized the relationship between microbiota and metabolites in response to microplastics, which could provide comprehensive insights into the potential risks of MPs on freshwater fish intestines. [ABSTRACT FROM AUTHOR]

Microplastics are widely distributed in deep oceans, with some of the highest concentrations reported in submarine canyons, which are thought to be closely related to turbidity currents. However, the turbidity current role in microplastic transport and deposition is poorly understood. Here, we present temporal variation in microplastic abundance and settling flux from sediment trap observations on the levee of Gaoping Canyon, offshore Taiwan, where turbidity currents occur frequently. The results showed that relatively high microplastic abundance and flux were consistent with the increases of near-bottom suspended sediment concentration caused by turbidity currents. The microplastics, dominated by polypropylene (59%) and polyethylene (21%), were probably derived from Taiwan coastal resuspension and river input and then transported into the submarine canyon by typhoon- or earthquake-triggered turbidity currents. During the turbidity currents, the average microplastic abundance and flux was 4137 particles per kilogram and 40.11 particles per square meter per day, respectively, showing an increase of 49% and 270%, respectively, compared to non–turbidity current periods. The total microplastic flux during the turbidity currents accounted for ∼76% of annual flux. Our study highlights turbidity currents to be the major hydrodynamic process in regulating microplastic transport and settling in a submarine canyon. [ABSTRACT FROM AUTHOR]

The continuously increasing accumulation of microplastics in the environment, such as polystyrene (PS), has posed an ecological and health threat. However, the information and biodegradation capability of plastics, including polystyrene, was still in the infancy stage in Indonesia. This study explored the potential of microbial consortia from Jakarta Bay to degrade polystyrene microplastics. The consortia were obtained from plastic waste with biofilms on their surfaces, collected from three stations in Jakarta Bay. The research enriched the biofilm's consortia using 1/10 Zobell marine broth media supplemented with 0.1% PS microplastics. Using enriched cultures, biodegradation tests were performed in a mineral salt medium with 0.2% PS microplastics as a sole carbon source for 60 days at 27°C, 120 rpm. Microbial consortia from Jakarta Bay showed an ability to perform polystyrene biodegradation. The calculated weight loss of the microplastics after 60 days of incubation was between 4% and 6.4%. The biodegradation of PS microplastics by the microbial consortium was also indicated by FTIR spectra, which showed changes in functional group transmittances and were confirmed by SEM data showing holes formation on PS surfaces. The results provide a baseline study for further research development in Indonesia's polystyrene biodegradation technology and management. [ABSTRACT FROM AUTHOR]

Recent scientific investigations have highlighted concerning levels of microplastic contamination in marine ecosystems, posing significant risks to marine organisms and human populations. This study aimed to assess the prevalence of microplastics in water, sediment, and tissues of commercially important fish species along the Malabar coast in Northwest Kerala, India. Using Fourier transform infrared spectroscopy (FTIR), six predominant polymer types were identified, including HDPE, PET, and nylon. The investigation revealed notable abundances of transparent microplastic particles, measuring <1 mm in diameter, particularly in gastrointestinal and gill tissues, with gastrointestinal tissues exhibiting the highest concentration of microplastics. A diverse array of morphotypes, including fragments (48.08%), fibers (28.84%), filaments (19.23%), and granules (3.85%), were observed within the coastal zone. The study implicates various sources of contamination, such as direct discharges, runoff, and inadequate wastewater management practices, contributing to the substantial presence of microplastics in coastal environments. In light of these findings, the study emphasizes the urgent need for the implementation of effective regulatory measures to mitigate plastic pollution in marine ecosystems. These results underscore the critical importance of proactive intervention to safeguard the health of marine ecosystems and human populations in coastal regions. [ABSTRACT FROM AUTHOR]

Plastic‐containing waste generated from industrial and household activities is usually discharged into rivers. Pekalongan Regency has several rivers that flow into the Java Sea, one of which is the Sengkarang River. Microplastic is a serious pollutant that has prompted enhanced research and experimentation. This study aims to determine the concentration and distribution of microplastics in water and sediment at the mouth of the Sengkarang River, Pekalongan. A total of 10 water samples and five sediment samples were collected from the river body to the deep water area around the Sengkarang River. Modeling of microplastic distribution is made using hydrodynamic modeling and particle tracking models using two‐dimensional mathematical model. The results showed that the abundance of microplastics ranged from 131 to 360 particle/m3 in water samples and 552.5–972.5 particle/kg in sediment samples. The most common types of microplastics found were fibers and fragments. The greatest abundance and distribution of microplastics are found in coastal areas in water samples and mangrove areas in sediment samples. The distribution of microplastics is influenced by tidal currents, wind directions, and also river water discharge. [ABSTRACT FROM AUTHOR]

Ditch irrigation is an important route that potentially discharges microplastics (MPs) into environment. Samiran ditch irrigation is the largest urban irrigation in Pamekasan City, Indonesia. Water and sediment samples were collected in Samiran ditch irrigation to identify MPs including their color, shape, size, and number of MPs. From all sampling locations, MPs were found in both the water and sediments of the Samiran ditch irrigation with sizes ranging from 0.1 mm to 2.9 mm. The abundance of MPs in water ranged from 0.5 to 0.9 items/L, while MPs in sediments 0.14 to 0.23 items/g with colors of black, blue, and yellow. The polymer types of polyethyleneimine (PEI) and polypropylene (PP) were found both in surface water and sediment sample. MPs such as fragments, filament, fiber, and pellet were found in Samiran ditch irrigation with fiber was dominant found in the surface water (40%) and fragment was dominant in sediment (25%). [ABSTRACT FROM AUTHOR]

In the realm of the global economy, agriculture holds a prominent status, acting as a vital source of employment and revenue for nations. Despite its crucial role, the agricultural sector contends with recurrent annual losses attributable to market fluctuations. One noteworthy contributor to the decline in agricultural productivity is the adverse impact of microplastics (MPs). This study aims to estimate the production losses suffered by key crops—rice, wheat, maize, tomato, and peas—due to MPs, along with the resulting economic consequences arising from the direct damage inflicted by MPs. To assess production losses caused by MPs, secondary data from diverse sources were employed for five plant varieties. The economic losses resulting from MPs were calculated for the period spanning 2017–2023, with cumulative data aggregated from all states. The study's findings indicate that the presence of MPs corresponds to an annual global output decline ranging from 0.4% to 34.7%. This decline translates to a reduction of approximately 0.01 million to 66.97 million tons per year in the production of food, fiber, and biofuels. The aggregate yearly economic losses are estimated at around USD 46.5 billion. These findings carry substantial implications for governmental policy in the agricultural domain, underscoring the necessity for current statistics on global losses incurred due to MPs. Moreover, they emphasize the importance of implementing a systematic surveillance system to monitor such losses effectively. [ABSTRACT FROM AUTHOR]

The dawn of mass plastic production in the early 20th century has accelerated the penetration of microplastics into the environment, making them known to be an insidious threat to diverse ecosystems. The current scenario for microplastics is dire, as they pervade living organisms and disrupt vital functions while also affecting the environment by altering soil quality. They pose an inherent risk to human health, making their elimination a multifaceted challenge. Due to factors such as small size, low biodegradability, and ubiquity, microplastics are particularly challenging to detect, and methods for their elimination from terrestrial and marine environments are an ever‐evolving field of research. The detection of such microplastics has necessitated the use of various biotechnological techniques to monitor microplastic pollution. The control of microplastic pollution in natural ecosystems can be met by replacing mass‐produced single‐use plastics with viable bio‐based alternatives. The main objectives of this review are to discuss how microplastic pollution is currently monitored, assessed, and controlled using satellite‐generated imagery complemented with a range of biotechnological and bioremedial techniques. This review also traces the development of a range of bio‐based plastic alternatives that are observed to potentially replace single‐use plastics. Further discussion on the various challenges and prospects for the mitigation of microplastics will also be conducted, stressing the importance of future research. [ABSTRACT FROM AUTHOR]

Although microplastics (MPs) in solid organic waste have been intensively studied, the presence of MPs in organic fertilizer and their potential as new emerging pollution to environment because of their use in agriculture has not been explained completely. Therefore, the identification and quantification of MPs in commercially available compost is important. This study aimed to estimate the quantity of MPs in commercial composts. The characteristics of MPs (shape, color, size, and type of polymers) were identified. This study found that MPs in commercial compost samples were found, reaching up to 160 particles/200 g of compost with various colors (blue, black, red, yellow, and white). The identified MPs had various sizes (0.1–1 mm) and shapes (81.8% fragment, 16.2% fiber, and 2% filament). The findings of this study are very important and significant to inform community and policymakers regarding the presence of MPs in commercial compost, hence, their intensive use in agriculture must be controlled and careful. [ABSTRACT FROM AUTHOR]

The present study investigated the effect of polypropylene (PP) microplastics on the growth performance, hematological profile and oxidative stress responses in the liver and brain tissues of Oreochromis niloticus juvenile. The microplastic exposure was done by offering microplastic‐incorporated feed to the fish. The feed was prepared by mixing microplastics and the feed in three different ratios; Low (1.5 g/kg), Medium (3.0 g/kg), High (4.5 g/kg), and a control with no plastics in it. The trial was done for 7 weeks. A significant impact on the growth performance of the fish was observed in terms of body weight gain, specific growth rate, metabolic growth rate, protein efficiency ratio and energy retention. All the treatments had a significant difference in growth parameters compared to the control. The results of the hematological profile confirmed erythropoietic impairment in the fishes due to high microplastic exposure which led to an anemic condition in the fishes and mortality in the early juvenile stage. The antioxidant enzyme analysis also shows significant oxidative stress induced in liver and brain tissues in a dose‐dependent manner. Exposure to PP microplastics significantly affected the growth, health and metabolism of O. niloticus. Further studies on genetic and cellular levels should be done to elucidate the wide‐ranging effects of MPs on fish species. [ABSTRACT FROM AUTHOR]

Mangroves are one of the most productive and diverse ecosystems offering a range of ecosystem services. Human interventions deteriorate mangrove ecosystems by converting them into a sink for all kinds of waste, including plastics and microplastics. Microplastics are potentially hazardous materials to ecosystems and human health due to their size, bioavailability, and potential for transmission of toxins and pathogens which necessitates their degradation. A significant strategy for microplastic degradation is by utilizing an indigenous microbial consortium. The current manuscript is a comprehensive review analysis of microplastic contamination in mangrove ecosystems and the possible degradation method by microorganisms. A thorough analysis of articles was done using different search engines and keywords. The result of the analysis showed that most of the literature dealt with isolation, separation, identification, and quantification of microplastics, techniques for identification of microplastics, an overview of microplastic biodegradation, and a few research articles focused on microbial degradation of microplastics. Although numerous articles were published, an all-inclusive manuscript considering various facets of microplastic pollution and microbial degradation possibilities was not seen. The exploration of the literature revealed significant gaps in microplastic research which can be relied upon for future study. [ABSTRACT FROM AUTHOR]

Heavy metals (HMs) and microplastics (MPs) are toxic environmental pollutants that severely risk ecosystems and living organisms. The interactions of these pollutants in the aquatic environment can impact their bioavailability, toxicity, and bioaccumulation potential in organisms. Various factors, including temperature, pH, salinity, polymer type, particle size and microbial abundance, influence these interactions and are likely to increase their influence on aquatic biota and human beings. MPs have been recognized as heavy metal transporters in aquatic environments that exhibit various harmful effects. However, MP interactions with heavy metals are poorly understood. Hence, it is important to understand the detailed mechanism, mainly absorption vs ingestion, MPs degradation with metal fate and combined effects on living organisms. To tackle and reduce the harmful effects on biodiversity, it is essential to comprehend the underlying mechanisms (e.g. adsorption, desorption, bio-uptake, and synergistic effects). Also, more research is required to comprehend the intricate connections between MPs and HMs in an array of environmental situations, which could lead to innovative solutions for mitigating their detrimental environmental consequences. This review paper discusses microplastic's prevalence, concentration, adsorption, and dissociation characteristics concerning HMs in aquatic ecosystems that must be understood to reduce their deleterious effects on aquatic biodiversity. Understanding these complex interactions between MPs and HMs is critical to assessing the ecotoxic effects and preventing environmental pollution. This review paper also underscores the nature of environmental pollutants, including the interaction mechanisms of MPs and HMs, emphasizing the importance of multifaceted approaches that need to be adapted to mitigate their combined effects. [ABSTRACT FROM AUTHOR]

Plastic waste in marine waters will undergo a degradation process that breaks down large plastic pieces into smaller particles called microplastics. The abundance of microplastics, caused by their small size (<5mm) can be easily indirectly consumed by aquatic animals. Anadara granosa is one of the bivalves that is quite vulnerable to microplastic contamination because it has the nature of a filter feeder which means it can sift particles and organic matter around it. The purpose of this study was to determine the characteristics, abundance, and types of microplastic polymers in blood clams (A. granosa). The results of microplastic observations made on 60 blood clams were 153 microplastic particles identified from 47 individuals (78%) of contaminated blood clams with an average microplastic abundance of 0.591 ± 0.083 item/gr. Fiber-type microplastics are the most dominant form found and blue is the most dominant color found in the sample. Based on the average abundance of microplastics in Anadara granosa in the coastal area of Palopo City, it is lower than several studies that have been conducted previously. Fourier Transform-Infra Red was conducted to determine the type of polymer in microplastics. Three types of polymers were found in the Anadara granosa samples polyethylene terephthalate (PET), polystyrene, and polyester. The three types of polymers have effects on human health such as respiratory problems, skin irritation, and genotoxicity. Action is needed to prevent microplastic pollution in Palopo City's rivers before microplastic pollution becomes more severe in the future. [ABSTRACT FROM AUTHOR]

Anthropogenic environmental pollution is a major development challenge in Ugandan rivers and lakes, the key drivers being industrialization, agriculture, and urbanization. The aim of the study was to assess the potential of heavy metal and microplastic contamination in River Mpanga, Fort Portal, Uganda. Triplicate water and sediment samples were collected from three sampling sites, preserved, and analyzed at the Chemistry Department, Makerere University for heavy metals, while microplastics analysis was conducted at NaFIRRI, Jinja. Sediment heavy metal contamination was assessed from the geoaccumulation index, while microplastic characterization and quantification were determined from stereomicroscopy and morphological features. Arsenic was the most prevalent metal with a mean concentration of 13.2 ppm thus higher than permissible maximum limits of WHO. The mean concentrations (ppm) of copper, lead, and cadmium were 0.01, 0.01, and 0.001 respectively, and below the permissible maximum. Sediment samples revealed very strong arsenic contamination, strong contamination for copper, moderate to strong contamination for lead, and a potential lack of contamination for cadmium. The higher concentrations of the heavy metals in the sediments compared to water could be attributed to bioaccumulation, as evidenced by the high geoaccumulation values. Microplastics occurred throughout the river and included fragments, filaments, film, pellets, form, and fibers. The presence of heavy metals and microplastics was attributed to anthropogenic activities within the river vicinity, which discharged heavy metal-laden waste into River Mpanga. High arsenic concentrations and sediment accumulation of contaminants pose serious potential public health threats to the local communities. [ABSTRACT FROM AUTHOR]

Background: Transport, accumulation, and degradation of microplastics (MiPs) in the aquatic environment represent a significant concern to the researchers and policy-makers, due to the detrimental impact on biota and human health through food ingestion. Although consistent investigations and research data are available worldwide, comparing the results is still challenging due to the need for more regulations regarding the sampling methods, analysis, and results reporting. The European regulatory efforts include studies on the MiPs transport in the western basin of the Danube River developed with active nets-based multipoint sampling methods from suspended sediments and proposed for standardization. In this context, the present study aimed to address for the first time the transport of MiPs in the Romanian sector of the Danube, starting after entering the country (Moldova Veche) and before the formation of the Danube Delta (Isaccea). Results: The multipoint nets sampling procedure facilitated the collection of suspended sediments in the water columns as deep as 0.0–0.6 and 3.0–3.6 m depths and near riverbed sediments (autumn 2022 sampling) during an extensive spatio-temporal study from spring 2022 until spring 2023. The estimate of the maximum annual transport of 46–51 and 93–100 t·y−1 for MiPs and total (micro–meso–macroplastics) MPs at Moldova Veche was based on 135 collected and processed samples using 2021 water flow data. Polyethylene (58–69%) and polypropylene (21–33%) were the main polymer components in the separated fragments, foils, microfibers, and different colors spheroids of MiPs (< 5 mm), and the foils and fibers of meso–macroplastics (5–100 mm). Advanced investigations highlighted various microstructural degradations of the plastic fragments at the micro- and nanoscale and attached minerals (clays) and heavy metals. Conclusion: This paper presents the first comprehensive data set for microplastic annual transport in the "Low Danube", filling the need for a complete transport assessment in one of the most significant European rivers. 4–5 times lower values were measured before the entrance to the Danube Delta than those from Moldova Veche. The investigations should continue, including flooding events, and the sampling points should be expanded to deeper water column layers during all the campaigns for further validation. Highlights: The first comprehensive data set for microplastic transport in the Romanian Danube. Polyethylene and polypropylene are the main polymer components of the separated plastics. Maximum annual transport of 46-51 and 93-100 t·y-1 for MiPs and total plastics, respectively. 4-5 times lower transport values near the entrance to the Danube Delta than close to country entering. The investigations should continue for further validation. [ABSTRACT FROM AUTHOR]

Plastics and other polymer-based compounds are inevitable in our day-to-day life starting from packaging to consumer goods. Awareness about recycling plastics is all known; however, it is not sufficient to contain their negative effects on the environment and health. Disintegration products of plastic called micro- and nano-plastics (M/NPs) are increasingly found in food and environmental samples, which are considered to be an invisible threat with greater impact. Yet, there are no comprehensive regulations to monitor the M/NPs in food and water samples. Considering their harmful effects, there is a need for appropriate detection techniques to effectively identify and quantify the M/NPs in food and environment. Conventional techniques such as the Fourier transform infrared spectroscopy, Raman spectroscopy and scanning electron microscopy are expensive, require lab and labor, and are not suitable for on-field real-time monitoring. Optical detection techniques using various probes and sensors have been extensively used in the fields of bioimaging, biosensing, molecular fingerprinting etc. Recent research suggests that these probes and sensors are effective in detecting and quantifying the M/NPs. In this regard, the distinctive features of visual, colorimetric and plasmonic detection techniques have proved their high-end applicability. Most of these detectors are based on the principles of fluorescence, localized surface plasmon resonance, colorimetry, surface-enhanced Raman spectroscopy and speckle pattern analysis. This review discusses the recent advancements in the field of optical detection for M/NPs, summarizing its advantages, salient features, drawbacks, and ideas for future research. [ABSTRACT FROM AUTHOR]

Among aquatic organisms, filter feeders are particularly exposed to the ingestion of microplastics (MPs) and nanoplastics (NPs). The present study investigates the effect of environmental microplastics (ENV MPs) and nanoplastics (ENV NPs) generated from macro-sized plastic debris collected in the Garonne River (France), and polystyrene NPs (PS NPs) on the freshwater bivalve Corbicula fluminea. Organisms were exposed to plastic particles at three concentrations: 0.008, 10, and 100 μg L−1 for 21 days. Gene expression measurements were conducted in gills and visceral mass at 7 and 21 days to assess the effects of plastic particles on different functions. Our results revealed: (i) an up-regulation of genes, mainly involved in endocytosis, oxidative stress, immunity, apoptosis, and neurotoxicity, at 7 days of exposure for almost all environmental plastic particles and at 21 days of exposure for PS NPs in the gills, (ii) PS NPs at the three concentrations tested and ENV MPs at 0.008 μg L−1 induced strong down-regulation of genes involved in detoxication, oxidative stress, immunity, apoptosis, and neurotoxicity at 7 days of exposure in the visceral mass whereas ENV MPs at 10 and 100 μg L−1 and all ENV NPs induced less pronounced effects, (iii) overall, PS NPs and ENV MPs 0.008 μg L−1 did not trigger the same effects as ENV MPs 10 and 100 μg L−1 and all ENV NPs, either in the gills or the visceral mass at 7 and 21 days of exposure. This study highlighted the need to use MPs and NPs sampled in the environment for future studies as their properties induce different effects at the molecular level to living organisms. [ABSTRACT FROM AUTHOR]

Plastic recycling facilities (PRF) are one of microplastic sources that may release into the environment. This study aims to identify the abundance and characteristics of microplastics potentially released from a PRF in Indonesia. Analysis of raw materials in the influent of the wastewater treatment plant (WWTP) showed a microplastic abundance of 485 particles/L. The dominant type of microplastic was the 2.5 μm - 5 mm size of fragmented highdensity polyethylene (HDPE). In the effluent of floating clarifier 3, the microplastic abundance detected was 98 particles/L, with low-density polyethylene (LDPE) as the dominant fragmented plastic ranging from 1.2-2.5 μm. Meanwhile, in the WWTP sludge, microplastics were identified with an abundance of 364.81 particles/kg. The microplastics found in the sludge were predominantly in the fragment form, composed of HDPE, with sizes ranging from 0.2-2.5 µm. This information is crucial for understanding the extent to which PRFs contribute to microplastic pollution in the environment. These findings emphasize the importance of implementing more effective wastewater management technologies in PRFs to reduce the release of microplastics into the environment. [ABSTRACT FROM AUTHOR]

Plastic particles are considered a concerning issue on a global scale. This research aimed to examine the existence and features of microplastics (MPs) as well as evaluate the removal efficiency (RE%) of household water filter systems (HWFS). The research was conducted in 12 areas distributed across Mosul City. Various techniques, including Fourier transform spectroscopy (FTIR), stereomicroscopy, and scanning electron microscopy (SEM), were employed to accurately detect the presence of microplastics, analyze morphological properties, such as color, shape, and size, and determine the polymer types. The research findings showed that the efficiency of HWFS ranged from 93% to 30%, affected by several factors, including filter age and the number of its stages. Fibers and fragments were the most commonly encountered shapes of MPs accounting for about 94% of the examined instances. Around 52% of the total was characterized by a transparent color. An estimated 35% of MPs sizes were smaller than 10 µm. Out of all considered polymer types, polyvinyl chloride (PVC) represented the highest percentage, around 58%. Moreover, PVC was found to have a higher risk index compared to other types of polymers. [ABSTRACT FROM AUTHOR]

Plastic, which has become an indispensable part of our daily life due to its wide range of uses, is produced worldwide by millions of tons, and most of it accumulates in the ecosystem. Microplastics (MPs), which emerge as a result of their decomposition over time, are found almost everywhere we live. Some foods can also have high MP concentrations. Fish and shellfish living in the sea and oceans appear to be one of the most important ways of MPs uptake through the food chain. At the same time, table salt and drinking water pose a threat to food safety in terms of the presence of MPs. Unfortunately, increased exposure to MPs can also bring health problems. For example, respiratory diseases, reproductive problems, change of microbiota, neurotoxicity, and even cancer are just a few of them. Therefore, this danger should be recognized and necessary precautions should be taken. Even small steps are needed in this area. It is extremely important for people to increase their awareness of this issue and for countries to prevent this threat with various policies. This review was written to explain how MPs threaten food safety and human health. Transmission routes of microplastics and possible health risks (Created with BioRender.com) [ABSTRACT FROM AUTHOR]

The current study evaluates the abundance and characteristics (shape, color and chemical composition) of microplastics (MPs) of the Tijuana River Basin, a binational river system shared by Mexico and the USA and located in the northwest corner of Mexico. The investigation was conducted on microplastics in the riverbed and river shoreline of 11 sites along the main tributaries of the Tijuana River. The median abundance of riverbed and river shoreline sediments was 118 and 183 MPs kg−1, respectively. The dominant shape found was fiber (65%) followed by fragments (19%) and films (10%); the predominant identified polymers were PP polypropylene (46%), PE polyethylene (34.3%) and PS polystyrene (11.4), with lower numbers of polyacrylic, polyamide (PA) and polyethylene terephthalate (PET). Eleven colors were recorded, the most abundant being black (43.7%) and transparent (22.6%). Wastewater treatment plant (WWTP) discharges, littering and inappropriate or insufficient solid waste management are the main sources of MPs. The results highlighted the widespread distribution of MPs in the Tijuana River Basin sediment. [ABSTRACT FROM AUTHOR]

Atmospheric microplastics are important contributors to environmental contamination in aquatic and terrestrial systems and pose potential ecological risks. However, studies on atmospheric microplastics are still limited in urban regions of the Tibetan Plateau, a sentinel region for climate and environmental change under a warming climate. In this study, the occurrence and potential ecological risk of atmospheric microplastics were investigated in samples of suspended atmospheric microplastics collected in Lhasa city during the Tibetan New Year in February 2023. The results show that the average abundance of atmospheric microplastics in Lhasa was 7.15 ± 2.46 MPs m−3. The sizes of the detected microplastics ranged from 20.34 to 297.18 μm, approximately 87% of which were smaller than 100 μm. Fragmented microplastics (95.76%) were the dominant shape, followed by fibres (3.75%) and pellets (0.49%). The primary polymer chemical components identified were polyamide (68.73%) and polystyrene (16.61%). The analysis of meteorological data and the backwards trajectory model indicated the air mass in Lhasa mainly controlled by westwards, and the atmospheric microplastics mainly originated from long-distance atmospheric transport. The potential ecological risk index assessment revealed that the atmospheric microplastic pollution in Lhasa was relatively low. This study provides valuable insights and a scientific foundation for future research on the prevention and control of atmospheric microplastic pollution in Lhasa and other ecologically sensitive cities. [ABSTRACT FROM AUTHOR]

AbstractPolyethylene (PE) is one of the most widely used plastics in the world. Its degradation leads to the production of small particles including microplastics and nanoplastics (NPs). Plastic particles’ presence poses a health risk. The aim of this work was to investigate the toxicity of two model surfactant-free PE NPs prepared by polymerization of ethylene from cationic and anionic water-soluble initiators on human cell lines Caco-2 and HT29-MTX. After physicochemical characterization, their acute and subacute toxicity profile, including cytotoxicity, oxidative stress, and genotoxicity, was evaluated on both cell lines. Results showed a size increase of PE NPs in culture medium. Zeta potential values close to −10 mV were no longer dependent on the initiator charge after adsorption of serum components in culture medium. However, the cellular toxicity of the cationic and anionic PE NPs was very different. A time-and-concentration dependent cytotoxic, oxidative, and genotoxic effects on Caco-2 cells were only observed for PE NPs prepared with cationic initiators. No toxicity was observed on HT29-MTX, likely due to the protective mucus layer. Genotoxicity correlated with oxidative stress of some PE NPs on Caco-2 cells was observed from a concentration of 0.1 mg.mL−1 after 48-h exposure. [ABSTRACT FROM AUTHOR]

Background: Microplastics (MPs) has been rapidly increasing and interacting with wildlife. As the highest altitudes inhabited non-human primate, Yunnan snubnosed monkey (Rhinopithecus bieti) have been proven to be an umbrella and flagship species to indicate ecosystem changes and help develop environmental management strategies. In this study, we aimed to investigate the behavioral and ecological reasons for the types, content and differences of MPs in the feces of R. bieti, and explored the effects of MPs on gut microbiome of R. bieti. Methods: We used the Agilent 8700 LDIR to identify the abundance and size distribution of MPs in fecal samples, and then analyzed the causes of differences in MPs content by combining data from different populations (wild group, provisioned wild group) and dominance hierarchy. At the same times, the relationships were investigated between gut microbiome diversity and MPs content. Results: We first demonstrate MPs ingestion by R. bieti, which highlights the potential impacts of MPs pollution in such high-altitude, inaccessible protected areas. A total of 36 types of MPs were detected, with an average of 75.263 ± 58.141MPs/g. Food provisioning and tourism significantly increased the content of MPs in the feces of R. bieti, but tourism alone did not significantly increase the content of MPs as food provisioning. At the same time, the study found that there was no significant difference in the content of MPs between different sex groups, however, the feces MPs content of adult R. bieti was significantly lower than that of juvenile, and the social dominance hierarchies among OMUs was positively correlated with the exposure of MPs. The current level of MPs pollution did not cause gut microbiome dysbiosis of R. bieti. Conclusion: Our study proved from behavioral and ecological perspectives that the R. bieti exposure to MPs was related to provisioned food, and was closely related to dominance hierarchy and age. From the perspective of intestinal microbiology, it was proved that the current intake of MPs did not cause gut microbiome dysbiosis of R. bieti. Our study provided scientific basis for formulating effective protection measures and promoting the effective protection of rare and endangered animals. [ABSTRACT FROM AUTHOR]

Microplastics and nanoplastics (MNPs) are present in urban dust and the aquatic environments of industrialized cities. MNPs in the human body accumulate in the lymphoid follicles, Peyer’s patches of the gastrointestinal tract, and pulmonary vascular endothelial cells, which slowly result in toxicity. Since previous studies introduced curcumin as a natural protective agent against environmental toxins, we reviewed preclinical studies that had used curcumin to protect organs or cells from toxicity secondary to exposure to MNPs. It was found that exposure to MNPs resulted in osteolysis, immunotoxicity, thyroid disturbances, nephrotoxicity, neurotoxicity, hepatotoxicity, pulmonary toxicity, gastrointestinal toxicity, cardiovascular toxicity, and especially endocrine, and reproductive toxicity. Nevertheless, except for one study reviewed, curcumin restored all oxidative and histopathological damages induced by MNPs to normal due to curcumin’s inherent antioxidant, antiapoptotic, anti-inflammatory, and anti-proliferative properties. [ABSTRACT FROM AUTHOR]

Microplastic pollution in the marine environment is of concern, with evidence of harmful effects onmarine biota and ecosystems. There is still a knowledge gap of the mass of plastics supplied to the ocean and plastics observed in the ocean, indicating a missing sink. Therefore, baseline and monitoring data are needed to inform policy and regulatory measures. The goal of this study was to collect harmonised data of microplastics from the surface of the ocean using the Neuston Microplastic Catamaran. This study shows that the surface water of the coastal ocean in the North Sea holds/sustains high concentrations of microplastic, which exceed previously recorded measurements from the North-East Atlantic and Scottish Waters, indicating that the total stock of plastics might be much higher than previously determined. Microplastics were detected in all samples with concentrations ranging from 857 to 25,462 items km-2. The majority of microplastics analysed were fragments of polyethylene, polypropylene, and polystyrene in the size range of 1,000--5,000 µm. Mesoplastics (>5,000 µm) mainly in the form of filaments were found with concentrations ranging from 0 to 2,139 items km-2, and macroplastics (>5,000 µm) in the form of fragments and filaments were also found with concentrations ranging from 0 to 1,078 items km-2. These fragments and filaments likely originate from the break-up of common macrolitter items in the environment, such as plastic bags, bottles, and fishing gears, which are commonly comprised of similar polymers to those found in the present study. Our findings demonstrate that litters of all size classes are abundant in surface water, highlighting that it is a key compartment for the transport of marine litter and should be monitored to better our understanding of the fate and danger of plastic contamination in our ocean. [ABSTRACT FROM AUTHOR]