Microplastics in bivalves cultured for human consumption

Microplastics in the sediments along the eastern Arabian Sea shelf: Distribution, governing factors and risk assessment

Despite the omnipresence of microplastics (MPs), the studies around the western continental shelf of Indian Ocean (Eastern Arabian Sea-EAS) are uncovered and understudied. Thus, the present study was focused to understand the spatial distribution, characterization and risk assessment of MPs in sediment across seven coastal transects (10 to 50 m) all along the EAS shelf. The highest MPs concentration (MPs/kg d.w.) was detected in the northern EAS (NEAS; 2260 ± 1050) followed by central (CEAS; 1550 ± 1012) and southern (SEAS; 1300 ± 513) shelves. Among all distinct locations, the highest concentration of MPs (2500 ± 1042) was detected in the north coastal sediments off Mumbai, followed by off Mangalore (1480 ± 1169) in the center and off Kochi (1350 ± 212) in the south. MPs were found in the form of fibres, fragments and films with a predominance of fibres (~70-80 %). Approximately 74.6 % of the total MPs were in the size range of 300 μm to 5 mm. The surface of detected MPs was rough, irregular, and mechanical weathering features such as pits, grooves also observed and spotted with bacterial community structures. Polypropylene (PP; 34 %), polyisoprene (PIP; 19 %), butyl rubber (18 %), and low-density polyethylene (LDPE; 13 %) were dominant polymers. The pollution load index highlighted minor risk while the polymer hazard index exhibited a hazard level of V. Litter discharge, fishing activities, and active marine navigation are among the many high-risk sources of plastic contamination in this region. Due to the prevailing winds, currents, low sea surface height, and high precipitation, the conditions in the EAS are favorable for the accumulation of both sea-based and land-based particles. Hence, this study provides novel insights into the potential risks posed by MP to the IO rim and associated marine ecosystem which will enhance our knowledge of the ecological implications and consequences of MP pollution, ultimately aiding in developing effective management and mitigation strategies.

Microplastics in Ecuador: A review of environmental and health-risk assessment challenges

Pollution from plastic debris and microplastics (MPs) is a worldwide issue. Classified as emerging contaminants, MPs have become widespread and have been found not only in terrestrial and aquatic ecosystems but also within the food chain, which affects both the environment and human health. Since the outbreak of COVID-19, the consumption of single-use plastics has drastically increased, intensifying mismanaged plastic waste in countries such as Ecuador. Therefore, the aim of this review is to 1) summarize the state of MP-related knowledge, focusing on studies conducted with environmental matrices, biota, and food, and 2) analyze the efforts by different national authorities and entities in Ecuador to control MP contamination. Results showed a limited number of studies have been done in Ecuador, which have mainly focused on the surface water of coastal areas, followed by studies on sediment and food. MPs were identified in all samples, indicating the lack of wastewater management policies, deficient management of solid wastes, and the contribution of anthropogenic activities such as artisanal fishing and aquaculture to water ecosystem pollution, which affects food webs. Moreover, studies have shown that food contamination can occur through atmospheric deposition of MPs; however, ingredients and inputs from food production, processing, and packaging, as well as food containers, contribute to MP occurrence in food. Further research is needed to develop more sensitive, precise, and reliable detection methods and assess MPs' impact on terrestrial and aquatic ecosystems, biota, and human health. In Ecuador specifically, implementing wastewater treatment plants in major cities, continuously monitoring MP coastal contamination, and establishing environmental and food safety regulations are crucial. Additionally, national authorities need to develop programs to raise public awareness of plastic use and its environmental effects, as well as MP exposure's effects on human health.

The first evidence of microplastic presence in the River Nile in Khartoum, Sudan: Using Nile Tilapia fish as a bio-indicator

The extent of microplastics in African freshwater systems remains less investigated. In Sudan, there is no single study reporting microplastics in water bodies. This scoping study aimed to investigate the presence and characteristics of microplastics (MPs) in Nile Tilapia fish from the River Nile in Khartoum, Sudan. The digestive tracts of the fish were digested using 10% potassium hydroxide, and microplastic particles were extracted by density separation using sodium iodide. 567 particles of different sizes (0.04-4.94 mm), shapes (fibers, fragments, films, foams, and pellets), and colours (mostly green, black, blue, and grey) were identified as microplastics. The average abundance of microplastics was 72.02 ± 62.06 particles/kg, and the average intensity was 18.90 ± 9.17 MPs/fish. Small-sized (<1 mm), fibrous-shaped, and coloured microplastics were most abundant in all samples, representing 56%, 85%, and 84%, respectively. Surface examination by SEM showed signs of fragmentation such as cracks, pits, and pores. Two polymer types (high-density polyethylene and polypropylene) were identified by Raman spectroscopy. The predominance of fibers and fragments (94.5%) over pellets (0.35%) and the apparent signs of fragmentation may indicate that MPs are mostly secondary MPs. Wastewater effluent, domestic discharge, and recreational activities are the potential sources. This scoping investigation provided the first data on microplastic presence in the River Nile in Khartoum, and it could be used to guide future studies to fill research gaps in the region.

The potential impacts of micro-and-nano plastics on various organ systems in humans

Humans are exposed to micro-and-nano plastics (MNPs) through various routes, but the adverse health effects of MNPs on different organ systems are not yet fully understood. This review aims to provide an overview of the potential impacts of MNPs on various organ systems and identify knowledge gaps in current research. The summarized results suggest that exposure to MNPs can lead to health effects through oxidative stress, inflammation, immune dysfunction, altered biochemical and energy metabolism, impaired cell proliferation, disrupted microbial metabolic pathways, abnormal organ development, and carcinogenicity. There is limited human data on the health effects of MNPs, despite evidence from animal and cellular studies. Most of the published research has focused on specific types of MNPs to assess their toxicity, while other types of plastic particles commonly found in the environment remain unstudied. Future studies should investigate MNPs exposure by considering realistic concentrations, dose-dependent effects, individual susceptibility, and confounding factors.

Stormwater outlets: A source of microplastics in coastal zones of Cape Town, South Africa

The runoff from stormwater outlets are potential sources of microplastics (MPs) in coastal zones. The characteristics and concentrations of MPs in coastal water, sediment and biota (mussels, whelks and sea urchins) were measured in summer (2020/2021) (dry season) and winter (2021) (wet season) from three sites (Camps Bay, Mouille Point and Three Anchor Bay) in Cape Town. MPs were characterised visually using a stereo microscope and chemically using spectroscopy. MP concentrations were higher in water and sediment during winter, and higher in biota in summer. Compared to control sites, MPs were higher at all impact sites sampled. MPs extracted were mainly black polyester (PEST) fibres, 1000 to 2000 μm in length averaging 0.15 MPs/L in water, 52.11 MPs/kg dry weight in sediment and 1.35 MPs/g soft tissue wet weight in biota. The results indicate that coastal stormwater systems are potential sources of MPs in the coastal environment of Cape Town.

Microplastics absent from reef fish in the Marshall Islands: Multistage screening methods reduced false positives

Island communities, like the Republic of the Marshall Islands (RMI), depend on marine resources for food and economics, so plastic ingestion by those resources is a concern. The gastrointestinal tracts of nine species of reef fish across five trophic groups (97 fish) were examined for plastics >1 mm. Over 2100 putative plastic particles from 72 fish were identified under light microscopy. Only 115 of these from 47 fish passed a plastic screening method using Fourier-transform infrared microspectroscopy (μFTIR) in reflectance mode. All of these were identified as natural materials in a final confirmatory analysis, attenuated total reflectance FTIR. The high false-positive rate of visual and μFTIR methods highlight the importance of using multiple polymer identification methods. Limited studies on ingested plastic in reef fish present challenging comparisons because of different methods used. No plastic >1 mm were found in the RMI reef fish, reassuring human consumers.

Microplastics in the insular marine environment of the Southwest Indian Ocean carry a microbiome including antimicrobial resistant (AMR) bacteria: A case study from Reunion Island

The increasing threats to ecosystems and humans from marine plastic pollution require a comprehensive assessment. We present a plastisphere case study from Reunion Island, a remote oceanic island located in the Southwest Indian Ocean, polluted by plastics. We characterized the plastic pollution on the island's coastal waters, described the associated microbiome, explored viable bacterial flora and the presence of antimicrobial resistant (AMR) bacteria. Reunion Island faces plastic pollution with up to 10,000 items/km2 in coastal water. These plastics host microbiomes dominated by Proteobacteria (80 %), including dominant genera such as Psychrobacter, Photobacterium, Pseudoalteromonas and Vibrio. Culturable microbiomes reach 107 CFU/g of microplastics, with dominance of Exiguobacterium and Pseudomonas. Plastics also carry AMR bacteria including β-lactam resistance. Thus, Southwest Indian Ocean islands are facing serious plastic pollution. This pollution requires vigilant monitoring as it harbors a plastisphere including AMR, that threatens pristine ecosystems and potentially human health through the marine food chain.

Plastic ingestion by three species of Scylla (Brachyura) from the coastal areas of Thailand

This study marked the first investigation into the presence of plastic particles in the stomachs of three mud crab species (Scylla olivacea, S. paramamosain and S. tranquebarica) collected across the Andaman Sea and the Gulf of Thailand. The highest number of plastic particles in the stomach of crab samples was polyethylene (PE) that contributed 88.5 %; while green was the predominant colour (60.3 %). Ingested particles recovered from the stomachs of crabs differed significantly between species and sites (p < 0.001). The average number of plastic particles per individual was 2.3 ± 8.6 in Scylla olivacea, 7.2 ± 16.9 in S. paramamosain, and 13.5 ± 48.9 in S. tranquebarica. Satun, revealed the highest number of plastic particles recovered from mud crabs, while the lowest number of plastic particles were from Pattani. To conclude, species of crab and site of collection plays a crucial factor in the propensity of plastic particles ingested by the genus Scylla mud crabs.

[Preparation of Degraded Microplastics That Imitate Surface Properties in the Environment]

Microplastics are small pieces of plastic that are less than 5 mm in length. These plastics have been detected in various environments, including the ocean, soil, and air. Their abundance have raised concerns regarding their potential effects on living organisms, including humans. The surface of microplastics degrades due to external factors such as ultraviolet rays and water waves in the environment. Therefore, assessing the biological impact of microplastics and considering their state of degradation is important. Among the physical properties of microplastics, we focused on the chemical degradation of microplastics. Specifically, we used vacuum ultraviolet (VUV) light to accelerate the degradation of polyethylene (PE) and prepared PE samples representing the degradation of PE to varying degrees. The surface properties of PE samples prepared using VUV were similar to those obtained from the environment. Cytotoxicity tests were then used to evaluate the effects of undegraded and degraded PE on cells. We found that the severity of cytotoxicity increased with the extent to which the PE would have been degraded, suggesting that the degree of degradation is strongly linked to the severity of the observed deleterious effects on living organisms. In conclusion, this finding contributes to our understanding of the effects of polyethylene microplastics on the human body.

Assessment of the estuarine shoreline microplastics and mesoplastics of the River Itchen, Southampton (UK) for contaminants and for their interaction with invertebrate fauna

The presence of shoreline microplastics (1-5 mm) and mesoplastics (5-25 mm) in estuarine ecosystems is ubiquitous, but there remains little data on their composition, contamination status and ecological impacts. Chessel Bay Nature Reserve, situated in the internationally protected Itchen Estuary in Southampton, UK, has serious issues with shoreline plastic accumulation. In evaluating potentially adverse ecological impacts, the influence of quantities of shoreline microplastic (mp) and mesoplastic (MeP) material and adsorbed contaminants (PAHs and trace metals) on the biometrics and population dynamics of the burrowing supralittoral amphipod, Orchestia gammarellus, was assessed in this study. mp/MeP concentrations were variable in surface (0-42%: 0-422,640 mg/kg dry sediment) and subsurface horizons (0.001-10%: 11-97,797 mg/kg dry sediment). Secondary microplastics accounted for 77% of the total microplastic load (dominated by fragments and foams), but also comprised 23% nurdles/pellets (primary microplastics). Sorption mechanisms between contaminants and natural sediments were proposed to be the main contributor to the retention of PAHs and trace metal contaminants and less so, by mp/MeP. O. gammarellus populations showed a positive correlation with microplastic concentrations (Spearman correlation, R = 0.665, p = 0.036). Some reported toxicological thresholds were exceeded in sediments, but no impacts related to chemical contaminant concentrations were demonstrated. This study highlights a protected site with the severe plastic contamination, and the difficulty in demonstrating in situ ecotoxicological impacts.

Exposure of Mytilus galloprovincialis to Microplastics: Accumulation, Depuration and Evaluation of the Expression Levels of a Selection of Molecular Biomarkers

Microplastic contamination is a growing marine environmental issue with possible consequences for seafood safety. Filter feeders are the target species for microplastic (MPs) pollution because they filter large quantities of seawater to feed. In the present study, an experimental contamination of Mytilus galloprovincialis was conducted using a mixture of the main types of MPs usually present in the seawater column (53% filaments, 30% fragments, 3% granules) in order to test the purification process as a potential method for removing these contaminants from bivalves intended for human consumption. A set of molecular biomarkers was also evaluated in order to detect any variations in the expression levels of some genes associated with biotransformation and detoxification, DNA repair, cellular response, and the immune system. Our results demonstrate that: (a) the purification process can significantly reduce MP contamination in M. galloprovincialis; (b) a differential expression level has been observed between mussels tested and in particular most of the differences were found in the gills, thus defining it as the target organ for the use of these biomarkers. Therefore, this study further suggests the potential use of molecular biomarkers as an innovative method, encouraging their use in next-generation marine monitoring programs.

Microbeads in personal care products sold in Pakistan: extraction, quantification, characterization, and buoyancy analysis

Microbeads used in personal care products (PCPs) as an exfoliating agent or as a sorbent phase for delivering active ingredients are the most common sources of microplastics. The release of these plastic microbeads into aquatic environments has raised significant concerns due to their direct availability for ingestion by organisms upon entering the recipient waters. In this study, twelve personal care products (PCPs; 5 face washes and 7 scrubs) were analyzed for microbead content, size, polymer type, and buoyant behavior. Among the face washes, the highest microbead content (i.e., 11 ± 1.2 mg/g) was found in Neutrogena (NS), while the lowest was found in Nivea (NI) with 0.33 ± 0 mg/g. In case of scrubs, Cool and Cool (CL) contained a higher concentration of microbeads (i.e., 57.08±14.15 mg/g) and a lower concentration was found in Yong Chin (YC) (i.e., 10.5±1.5 mg/g). The sizes of microbeads ranged from 3.14 ± 0 to 747 ± 313 μm, and most of the isolated microbeads showed negative buoyant behavior in both freshwater and seawater. The FTIR spectra showed that the microbeads were mainly composed of ethyl-vinyl acetate (66.66%), high-density polyethylene (16.66%), polyethylene terephthalate (8.3%), and nitrile (8.3%). The presence of plastic microbeads in PCPs highlights the need to regulate their use as an exfoliating agent and to raise public awareness to prevent the discharge of these persistent and potentially harmful elements into the environment.

Recent progress of microplastic toxicity on human exposure base on in vitro and in vivo studies

Microplastics are widely distributed in the environment, including the atmosphere, soil and water bodies. They have been found to have toxic effects on organisms. The impact on human health is also receiving considerable attention. Microplastics can be found in drinking water, food, air and plastic products, and they can enter human body through the pathways such as ingestion, inhalation, and skin contact. After exposure to microplastics, they can induce cellular toxicity and produce toxic effects on multiple organs and systems, including the digestive, respiratory, nervous, reproductive and cardiovascular systems. This paper presents a comprehensive review and analysis on the recent progress of human exposure studies, in vitro experiments, rodent experiments, and other model experiments in microplastic human toxicity research. It comprehensively analyzes the potential human toxic effects of microplastics, providing a theoretical basis for further research on microplastic human toxicity and its mechanisms. Furthermore, this paper highlights the knowledge gaps and provides the recommendations for future research on human toxicity of microplastics.

Microplastic induces mitochondrial pathway mediated cellular apoptosis in mussel (Mytilus galloprovincialis) via inhibition of the AKT and ERK signaling pathway

Microplastics (MPs) is an escalating aquatic environmental crisis that poses significant threats to marine organisms, especially mussels. Here, we compare the cumulative toxic effects of the two most abundant morphotypes of MPs in the environment, microspheres, and microfibers, on the gill and digestive gland (DG) of Mytilus galloprovincialis in a dose-dependent (1, 10, and 100 mg/L) and time-dependent (1, 4, 7, 14, 21 days exposure) manner. DNA fragmentation assessment through TUNEL assay revealed consistency in the pattern of morphological disturbance degree and cell apoptosis proportions indicated by histopathological analysis. Upon the acute phase of exposure (day 1-4), gill and DG treated with low MPs concentration exhibited preserved morphology and low proportion of TUNEL+ cells. At higher concentrations, spherical and fibrous MP-induced structural impairments and DNA breakage occurred at distinct levels. 100 mg/L microfibers was lethal to all mussels on day 21, indicating the higher toxicity of the fibrous particles. During the chronic phase, both morphological abnormalities degree and DNA fragmentation level increased over time and with increasing concentration, but the differentials between the spherical and fibrous group was gradually reduced, particularly diminished in 10 and 100 mg/L in the last 2 weeks. Furthermore, analysis of transcriptional activities of key genes for apoptosis of 100 mg/L-day 14 groups revealed the upregulation of both intrinsic and extrinsic apoptotic induction pathway and increment in gene transcripts involving genotoxic stress and energy metabolism according to MP morphotypes. Overall, microfibers exert higher genotoxic effects on mussel. In response, mussels trigger more intense apoptotic responses together with enhanced energy metabolism to tolerate the adverse effects in a way related to the accumulation of stimuli.

Forecasting global plastic production and microplastic emission using advanced optimised discrete grey model

Plastic pollution has become a prominent and pressing environmental concern within the realm of pollution. In recent times, microplastics have entered our ecosystem, especially in freshwater. In the contemporary global landscape, there exists a mounting apprehension surrounding the manifold environmental and public health issues that have emerged as a result of the substantial accumulation of microplastics. The objective of the current study is to employ an enhanced grey prediction model in order to forecast global plastic production and microplastic emissions. This study compared the accuracy level of the four grey prediction models, namely, EGM (1,1, α, θ), DGM (1,1), EGM (1,1), and DGM (1,1, α) models, to evaluate the accuracy levels. As per the estimation of the study, DGM (1,1, α) was found to be more suitable with higher accuracy levels to predict microplastic emission. The EGM (1,1, α, θ) model has slightly better accuracy than the DGM (1,1, α) model in predicting global plastic production. Various accuracy measurement tools (MAPE and RMSE) were used to determine the model's efficiency. There has been a gradual growth in both plastic production and microplastic emission. The current study using the DGM (1,1, α) model predicted that microplastic emission would be 1,084,018 by 2030. The present study aims to provide valuable insights for policymakers in formulating effective strategies to address the complex issues arising from the release of microplastics into the environment and the continuous production of plastic materials.

Co-exposure to cadmium and microplastics promotes liver fibrosis through the hemichannels -ATP-P2X7 pathway

Microplastics (MPs) and cadmium (Cd) are important environmental pollutants, that damage the liver. However, the effect and mechanism of combined Cd and MPs exposure on liver fibrosis are still largely unknown. In this study investigated, Cd + MPs exposure increased superoxide anion production and promoted extracellular ATP release compared with exposure to Cd or MPs individually. Cd + MPs increased inflammatory cell infiltration, activated the P2X7-NLRP3 signaling pathway, and promoted inflammatory factor release. Cd + MPs aggravated Cd- or MPs-induced liver fibrosis and induced liver inflammation. In AML12/HSC-T6 cell in vitro poisoning model, exposure of AML12 cells to Cd + MPs increased the opening of connexin hemichannels and promoted extracellular ATP release. Treatment of HSC-T6 cells with the supernatant of AML12 cells exposed to Cd + MPs significantly promoted HSC-T6 cell activation. Treatment of HSC-T6 cells with different concentrations of ATP produced similar results. TAT-Gap19TFA, an inhibitor of connexin hemichannels, significantly inhibited the ATP release and activation of Cd + MPs-treated HSC-T6 cells. Finally, the expression of the ATP receptor P2X7 was silenced in HSC-T6 cells, which significantly inhibited their activation. In conclusion, exposure to Cd + MPs promoted liver fibrosis through the ATP-P2X7 pathway and synergistically affected liver inflammation and fibrosis.

Review on impacts of micro- and nano-plastic on aquatic ecosystems and mitigation strategies

The rapid proliferation of microplastics (MPs) and nanoplastics (NPs) in our environment presents a formidable hazard to both biotic and abiotic components. These pollutants originate from various sources, including commercial production and the breakdown of larger plastic particles. Widespread contamination of the human body, agroecosystems, and animals occurs through ingestion, entry into the food chain, and inhalation. Consequently, the imperative to devise innovative methods for MPs and NPs remediation has become increasingly apparent. This review explores the current landscape of strategies proposed to mitigate the escalating threats associated with plastic waste. Among the array of methods in use, microbial remediation emerges as a promising avenue for the decomposition and reclamation of MPs and NPs. In response to the growing concern, numerous nations have already implemented or are in the process of adopting regulations to curtail MPs and NPs in aquatic habitats. This paper aims to address this gap by delving into the environmental fate, behaviour, transport, ecotoxicity, and management of MPs and NPs particles within the context of nanoscience, microbial ecology, and remediation technologies. Key findings of this review encompass the intricate interdependencies between MPs and NPs and their ecosystems. The ecological impact, from fate to ecotoxicity, is scrutinized in light of the burgeoning environmental imperative. As a result, this review not only provides an encompassing understanding of the ecological ramifications of MPs and NPs but also highlights the pressing need for further research, innovation, and informed interventions.

Quick and efficient microplastic isolation from fatty fish tissues by surfactant-enhanced alkaline digestion

For monitoring microplastic contamination in fish tissues, tissue digestion into filterable components prior to microplastic identification and quantification should be quick and efficient, providing satisfying microplastic recoveries of relevant particle sizes. Filtration with a small pore size, necessary to target small particles, is a challenge. Some proposed protocols take several days. To improve this, a combination of surfactants (Tween®-20 and Triton™ X-100) with potassium hydroxide (KOH) and pH neutralization was used. Fish bones were removed in tissue preparation prior to digestion. Recovery down to ca. 60-80 μm worked well for PA-66, PE, PET, PP, PS and PVC. In conclusion, we developed a comparatively swift digestion protocol, enabling filtration of 100 g samples with a pore size of 10 μm, for fish fillets with high (mackerel), intermediate (salmon, plaice) and low (cod) fat contents, fish liver, head kidney and oil samples, within 16-24 h.

Microplastic accumulation in bivalves collected from different coastal areas of Vietnam and an assessment of potential risks

Microplastic (MP) pollution is an emerging problem in many areas around the world and in coastal areas of Vietnam, requiring more studies dedicated to the accumulation of this pollutant in the food chain as well as its potential risk to human health. This study investigated MP levels in tissues of five common bivalve species collected from aquaculture areas along the coast of Vietnam. MPs were found in all bivalve samples, with average values of 10.84 ± 2.61 items/individual or 2.40 ± 1.34 items/g wet weight. Impacts of feeding habits of bivalves showed influences on MP abundance in the samples. Fibers were the dominant shape of MPs recorded, most of which accumulated in the gills and digestive glands of all bivalve samples, with the majority falling within the size range of 300-2000 µm. MPs found in all studied species had relatively similar chemical compositions, mainly composed of polypropylene (PP) and polyethylene (PE). In this study, a diverse diet consisting of different bivalve species and detailed data on the consumption rate of these species were used to assess the human health risk of MPs dedicated to the coastal communities of Vietnam. The results suggested a significant part of MP uptake by human could be via bivalve consumption, in which removing viscera and proper depuration should be applied prior to eating, thereby reducing the risk.

Cellular and bioenergetic effects of polystyrene microplastic in function of cell type, differentiation status and post-exposure time

The ubiquity of microplastics (MPs) in food sources and personal care products increasingly raises concerns on human health. However, little is known about the duration of the effects of MPs and whether effects depend on cellular differentiation status. Herein, cellular and bioenergetic effects of MPs in different exposure scenarios on four types of human cell lines derived from lung (A549 and BEAS-2B), colon (Caco-2) and liver (HepG2) were investigated. These cell lines are models for the major exposure routes in the body (inhalation, ingestion and physiological transport through the liver by the portal vein). To this aim, different scenarios were implemented by exposing undifferentiated and differentiated cells to single dosing of 2-μm polystyrene (PS) (102-105 particles/mL) for 48 h and 12 days. The undifferentiated Caco-2 cells with short exposure (48 h) showed the highest uptake rate of PS yet without significant cellular and mitochondrial responses. The biological effects, with the exception of ROS production, were not influenced by differentiation states of A549 and Caco-2 cells although differentiated cells showed much weaker ability to internalize PS. However, PS had significantly long-term impacts on cellular and mitochondrial functions even after the initial exposure period. In particular, Caco-2 cells that were post-exposed for 12 days after single PS dosing suffered higher oxidative stress and exhibited mitochondrial dysfunction than that for short exposure. Correspondingly, we observed that PS particles still remained in cell membrane and even in nuclei with high retention rate by 14-d post exposure during which metabolism and exchange of internalization and release occurred in cells. This indicates PS could induce chronic stress and even harmful effects on human cells after single intake that persists for a long time. This study paves the way for assessing the influence of PS on human health at low particle concentrations and with multiple exposure scenarios.

Fabrication of Polypropylene Nanoplastics Via Thermal Oxidation Reaction for Human Cells Responsiveness Studies

With the current worldwide increasing use of plastics year by year, nanoplastics (NPs) have become a global threat to environmental and public health concerns. Among plastics, polypropylene (PP) is widely used in industrial and medical applications. Owing to the lack of validated detection methods and standard materials for PP NPs, understanding the impact of PP NPs on the environmental and biological systems is still limited. Here, isotactic polypropylene (iPP) was fabricated into oxidized polypropylene micro/nanoplastics (OPPs) via a thermal oxidation using hydrogen peroxide (H2O2) under various heating temperatures. The resulting OPPs were investigated in terms of the size distribution, surface chemistry, morphology, and thermal property as well as their concentration-dependent cytotoxicity to a human intestinal epithelial cell line (Caco-2), which could be a route to uptake NPs into the body through the food chain. The average diameters of the OPPs decrease with increasing reaction temperature. The OPPs obtained at 175 °C (OPP175) were spherical in shape and had a rough surface, with size distributions of approximately 0.14 ± 0.02 μm. A significant increase in the carbonyl content of the oxidized product was confirmed by Fourier transform infrared and X-ray photoelectron spectroscopy analyses. Caco-2 cells were exposed to OPP175 in a dose-dependent manner, and a significant loss of cell viability occurred at the concentration of 100 μg/mL. Thus, this study provides a fundamental approach for the fabrication of a model of NPs for the urgently demanded in vitro and in vivo studies to assess the potential impact of NPs on biological systems.

Anthropogenic Microparticles in Sea-Surface Microlayer in Osaka Bay, Japan

The abundance, distribution, and composition of microparticles (MPs) in the sea-surface microlayer (S-SML, less than 100 μm of sea surface in this experiment) and in bulk water (1 m under the sea surface) were investigated to evaluate the pollution level of MPs in Osaka Bay in Japan. Both seawater fractions were collected at eight sites including ship navigation routes, the coastal area, and the center of Osaka Bay for 2021-2023. MPs were filtered for four size ranges (10-53, 53-125, 125-500, and >500 μm) and then digested with H2O2. MPs' abundance was microscopically assessed; and polymer types of MPs were identified by a Fourier transform infrared spectrometer (FTIR). For the 22 collections performed along eight sites, the average MPs' abundance was 903 ± 921 items/kg for S-SML, while for the 25 collections performed along the same sites, the average MPs' abundance was 55.9 ± 40.4 items/kg for bulk water, respectively. MPs in both S-SML and bulk water exhibited their highest abundance along the navigation routes. The smallest MPs (10-53 μm) accounted for 81.2% and for 62.2% of all MPs in S-SML and in bulk water among all sites, respectively. Polymethyl methacrylate (PMMA) was the major type of MPs identified while minor ones were polyethylene, polyesters, polystyrene, polypropylene, polyvinyl chloride, polyamide, etc. PMMA comprised 95.1% of total MPs in S-SML and 45.6% of total MPs in bulk water. In addition, PMMA accounted for 96.6% in S-SML and 49.5% in bulk water for the smallest MP category (10-53 μm). It can be assumed that the MP sources were marine paints-primarily APPs (antifouling paint particles)-as well as land coatings. Sea pollution due to microparticles from ship vessels should be given proper attention.

Microplastics and biobased polymers to combat plastics waste

Microplastics (MPs) have become the major global concern due to their adverse effects on the environment, human health, and hygiene. These complex molecules have numerous toxic impacts on human well-being. This review focuses on the methods for chemically quantifying and identifying MPs in real-time samples, as well as the detrimental effects resulting from exposure to them. Biopolymers offer promising solutions for reducing the environmental impact caused by persistent plastic pollution. The review also examines the significant progress achieved in the preparation and modification of various biobased polymers, including polylactic acid (PLA), poly(ε-caprolactone) (PCL), lignin-based polymers, poly-3-hydroxybutyrate (PHB), and poly(hydroxyalkanoates) (PHA), which hold promise for addressing the challenges associated with unplanned plastic waste disposal.

Microplastic Pollution in the Gastrointestinal Tract and Gills of Some Teleost and Sturgeon Fish from the Caspian Sea, Northern Iran

The increasing microplastic pollution in the marine environment has raised global concern. The main risk of microplastics in aquatic ecosystem is their bioaccumulation in aquatic organisms. A few studies have reported microplastic pollution in the digestive system of Caspian Sea fish species, but there is no research on sturgeon species, nor on fish gills. We investigated the occurrence of microplastics in the gastrointestinal tract (GIT) and gills of 62 specimens belonging to four species including three teleosts (Cyprinus carpio, Rutilus kutum, and Chelon aurata) and one sturgeon (Acipenser persicus, a valuable endangered species) from the Caspian Sea between January and March 2022. Fish tissues were removed, exposed for 24 h to 10% KOH, and then dried on filter paper. Particles were observed under a stereomicroscope and analyzed by Raman microspectrometry, scanning electron microscopy, and energy-dispersive spectroscopy. A total of 91 microplastics were detected in the GIT (average of 1.46 ± 1.17 items/individual) and 63 microplastics in the gills (average of 1.01 ± 0.62 items/individual). A significant correlation was not found between the number of microplastics found in both tissues and fish body length, body weight, GIT weight, and gill weight (p > 0.05), except between microplastics isolated from gills and gill weight in C. carpio (rs  = 0.707, p = 0.022). The abundance of microplastics in fish followed the order of A. persicus > C. aurata > R. kutum > C. carpio. The microplastics were in the size range of 45 to 5000 µm, with particles of 300 to 1000 µm being the most prevalent; 74.68% of the particles were shaped like fibers, 30.53% were red, and 70.6% were composed of nylon polymer. Environ Toxicol Chem 2023;42:2453-2465. © 2023 SETAC.

Exposure sources and pathways of micro- and nanoplastics in the environment, with emphasis on potential effects in humans: A systematic review

Microplastics (MPs) are emerging pollutants that are ubiquitous in the environment, and may be a potential threat to human health. This review describes the MP exposure sources and pathways through drinking water, food intake, and air inhalation. The unregulated discharge of MPs in water sources and the absence of required MP filter technology in water treatment plants are important routes of MP exposure through drinking water. The presence of MPs in food may lead to the accumulation of MPs in the body. Exposure to MPs can occur through airborne fallout and dust inhalation in both indoor and outdoor environments. This review summarizes the MP exposure sources and possible pathways in the human body, and illustrates that the intake of drinking water, food consumption, and air inhalation should be assessed in during routine activities. Integr Environ Assess Manag 2023;19:1422-1432. © 2023 SETAC.

Micro(nano)plastics in commercial foods: A review of their characterization and potential hazards to human health

Micro (nano)plastics (MNPs) are pollutants of worldwide concern for their ubiquitous environmental presence and associated impacts. The higher consumption of MNPs contaminated commercial food can cause potential adverse human health effects. This review highlights the evidence of MNPs in commercial food items and summarizes different sampling, extraction, and digestion techniques for the isolation of MNPs, such as oxidizing digestion, enzymatic digestion, alkaline digestion and acidic digestion. Various methods for the characterization and quantification of microplastics (MPs) are also compared, including μ-Raman spectroscopy, μ-Fourier transform infrared spectroscopy (FTIR), thermal analysis and Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). Finally, we share our concerns about the risks of MNPs to human health through the consumption of commercial seafood. The knowledge of the potential human health impacts at a subcellular or molecular level of consuming mariculture products contaminated with MNPs is still limited. Moreover, MNPs are somewhat limited, hard to measure, and still contentious. Due to the nutritional significance of fish consumption, the risk of exposure to MNPs and the associated health effects are of the utmost importance.

Assessing micro and nanoplastics toxicity using rodent models: Investigating potential mitochondrial implications

Mitochondria's role as a central hub in cellular metabolism and signaling cascades is well established in the scientific community, being a classic marker of organisms' response to toxicant exposure. Nonetheless, little is known concerning the effects of emerging contaminants, such as microplastics, on mitochondrial metabolism. Micro- and nanoplastics present one of the major problems faced by modern societies. What was once an environmental problem is now recognized as an one-health issue, but little is known concerning microplastic impact on human health. Indeed, only recently, human exposure to microplastics was acknowledged by the World Health Organization, resulting in a growing interest in this research topic. Nonetheless, the mechanisms behind micro- and nanoplastics toxicity are yet to be understood. Animal models, nowadays, are the most appropriate approach to uncovering this knowledge gap. In the present review article, we explore investigations from the last two years using rodent models and reach to find the molecular mechanism behind micro- and nanoplastics toxicity and if mitochondria can act as a target. Although no research article has addressed the effects of mitochondria yet, reports have highlighted molecular and biochemical alterations that could be linked to mitochondrial function. Furthermore, certain studies described the effects of disruptions in mitochondrial metabolism, such as oxidative stress. Micro- and nanoplastics may, directly and indirectly, affect this vital organelle. Investigations concerning this topic should be encouraged once they can bring us closer to understanding the mechanisms underlying these particles' harmful effects on human health.

Microparticles in marine mussels at regional and localized scales across the Salish Sea, Washington

Microparticles (MP; particles <5 mm) are ubiquitous in marine environments. Understanding MP concentrations at different spatial scales in the Salish Sea, Washington, USA, can provide insight into how ecologically and economically important species may be affected. We collected mussels across the Salish Sea at regional and localized scales, chemically processed tissue to assess MP contamination, and used visual and chemical analyses for particle identification. Throughout the Salish Sea, mussel MP concentrations averaged 0.75 ± 0.09 MP g-1 wet tissue. At a regional scale, we identified slight differences in concentrations and morphotypes of MP while at a localized scale these metrics were not significant and did not differ from controls. In a subset of particles, 20 % were identified as synthetic materials, which include polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), and nylon. Differences in MP sources, heterogeneous transport of MP, and distinct shellfish feeding mechanisms may contribute to plastic contamination patterns in the Salish Sea.

Metabolomics reveals that PS-NPs promote lung injury by regulating prostaglandin B1 through the cGAS-STING pathway

Nanoplastics have been widely studied as environmental pollutants, which can accumulate in the human body through the food chain or direct contact. Research has shown that nanoplastics can affect the immune system and mitochondrial function, but the underlying mechanisms are unclear. Lungs and macrophages have important immune and metabolic functions. This study explored the effects of 100 nm PS-NPs on innate immunity, mitochondrial function, and cellular metabolism-related pathways in lung (BEAS-2B) cells and macrophages (RAW264.7). The results had shown that PS-NPs exposure caused a decrease in mitochondrial membrane potential, intracellular ROS accumulation, and Ca2+ overload, and activated the cGAS-STING signaling pathway related to innate immunity. These changes had been observed at concentrations of PS-NPs as low as 60 μg/mL, which might have been comparable to environmental levels. Non-target metabolomics and Western Blotting results confirmed that PS-NPs regulated prostaglandin B1 and other metabolites to cause cell damage through the cGAS-STING pathway. Supplementation of prostaglandin B1 alleviated the immune activation and metabolic disturbance caused by PS-NPs exposure. This study identified PS-NPs-induced innate immune activation, mitochondrial dysfunction, and metabolic toxicity pathways, providing new insights into the potential for adverse outcomes of NPs in human life.

Microplastics in lentic environments: implications for Indian ecosystems

The paper focused on occurrence, characterization, and analytical methods of microplastic (MP) pollution in the lentic environment mainly for the Indian scenario. To understand the flow of MP from plastic waste, a material flow diagram was developed using STAN, assigning the transfer coefficients based on existing scientific literature and primary survey from local recycling facilities and industries. The quantity, morphology, and polymers of MP in the water and sediments of the lentic environment were compared for various states from 2011 to 2022. The reasons for the geographical heterogeneity in microplastics may be the migratory routes of MPs in the ecosystems like commercial uses and wastewater characteristics which possibly discharged in lentic system. Factors like particle density, water surface area, water surface depth, wind speed and direction, and water flow size mainly affect MP concentrations in the lentic water body, and mainly PHI and PLI are keys to MP risk analysis. The surface characteristics of MPs reveal that it absorbs many toxic contaminants including heavy metals. The impacts of MP on ecosystem and human health were also discussed. The impacts of socioeconomic conditions on MP concentrations for different states in India were also added. Proposed methods for plastic waste generation control also included which will help for developing policy in future to prevent MP pollution in lentic environments and also motivate future researchers to establish new standardized methods of MP analysis.

Journey of micronanoplastics with blood components

The entry of micro- and nanoplastics (MNPs) into the human body is inevitable. They enter blood circulation through ingestion, inhalation, and dermal contact by crossing the gut-lung-skin barrier (the epithelium of the digestive tract, the respiratory tract, and the cutaneous layer). There are many reports on their toxicities to organs and tissues. This paper presents the first thorough assessment of MNP-driven bloodstream toxicity and the mechanism of toxicity from the viewpoint of both MNP and environmental co-pollutant complexes. Toxic impacts include plasma protein denaturation, hemolysis, reduced immunity, thrombosis, blood coagulation, and vascular endothelial damage, among others, which can lead to life-threatening diseases. Protein corona formation, oxidative stress, cytokine alterations, inflammation, and cyto- and genotoxicity are the key mechanisms involved in toxicity. MNPs change the secondary structure of plasma proteins, thereby preventing their transport functions (for nutrients, drugs, oxygen, etc.). MNPs inhibit erythropoiesis by influencing hematopoietic stem cell proliferation and differentiation. They cause red blood cell and platelet aggregation, as well as increased adherence to endothelial cells, which can lead to thrombosis and cardiovascular disease. White blood cells and immune cells phagocytose MNPs, provoking inflammation. However, research gaps still exist, including gaps regarding the combined toxicity of MNPs and co-pollutants, toxicological studies in human models, advanced methodologies for toxicity analysis, bioaccumulation studies, inflammation and immunological responses, dose-response relationships of MNPs, and the effect of different physiochemical characteristics of MNPs. Furthermore, most studies have analyzed toxicity using prepared MNPs; hence, studies must be undertaken using true-to-life MNPs to determine the real-world scenario. Additionally, nanoplastics may further degrade into monomers, whose toxic effects have not yet been explored. The research gaps highlighted in this review will inspire future studies on the toxicity of MNPs in the vascular/circulatory systems utilizing in vivo models to enable more reliable health risk assessment.

Modified polyamide fibers with low surface friction coefficient to reduce microplastics emission during domestic laundry

The widespread presence of microplastics has become a serious threat to humans and ecological environments because they carry many pollutants and can be easily ingested by aquatic organisms. Fibrous microplastics (FMPs) released from synthetic fiber garments during domestic laundry are a major source of contamination. Herein, we report a facile FMPs mitigation strategy for polyamide 6 (PA6) fibers by incorporating environmentally friendly polydimethylsiloxane (PDMS) during melt spinning. The obtained PA6/PDMS fibers showed a lower friction coefficient than the pure PA6 fibers. Surface morphology, tribology, and washing characterizations verified that a 60% reduction in FMPs shedding was achieved by reducing the friction. In addition, the low-surface-friction PA6/PDMS fabrics with high hydrophobicity exhibited improved waterproof and anti-stain behaviors. It is important to note that none of the essential properties, such as surface structure, dyeing and printing of the fabrics were compromised after PDMS blending. This study provides a green and scalable route for mitigating laundry microfibers using a fiber domain design.

Approach to an answer to "How dangerous microplastics are to the human body": A systematic review of the quantification of MPs and simultaneously exposed chemicals

This review aims to facilitate future research on microplastics (MPs) in the environment using systematic and analytical protocols, ultimately contributing to assessment of the risk to human health due to continuous daily exposure to MPs. Despite extensive studies on MP abundance in environment, identification, and treatment, their negative effects on human health remain unknown due to the lack of proof from clinical studies and limited technology on the MP identification. To assess the risk of MPs to human health, the first step is to estimate MP intake via ingestion, inhalation, and dermal contact under standardized exposure conditions in daily life. Furthermore, rather than focusing on the sole MPs, migrating chemicals from plastic products should be quantified and their health risk be assessed concurrently with MP release. The critical factors influencing MP release and simultaneously exposed chemicals (SECs) must be investigated using a standardized identification method. This review summarises release sources, factors, and possible routes of MPs from the environment to the human body, and the quantification methods used in risk assessment. We also discussed the issues encountered in MP release and SEC migration. Consequently, this review provides directions for future MP studies that can answer questions about MP toxicity to human health.

Microplastics in marine-derived traditional Chinese medicine, potential threat to patients

Microplastics (MPs) contamination is widely found in marine organisms. Marine traditional Chinese medicines (MTCM) are derived from marine organisms, but there are no relevant reports on detecting MPs in MTCM. This study selected samples of MTCM from two representative pharmaceutical companies, Brand F and Brand Z, including mother-of-pearl, stone cassia, seaweed, pumice, oyster, kombu, calcined Concha Arcae, cuttlebone, and clam shell to detect and analyze the presence of MPs. The abundance, type, color, size, and composition of MPs were investigated. Varying degrees of MPs contamination was present in all MTCM. The abundance of MPs in different MTCM ranged from 0.07 to 9.53 items/g. Their type, color, and size are similar, mainly fiber, transparent and size <2 mm. The composition of MPs is primarily made of cotton, cellulose and rayon. This study contributes to the first record of MPs in MTCM. Our results show that microplastic pollution is common in MTCM, which may cause potential risk to patients consuming MTCM.

Microplastics in stomach contents of juvenile Patagonian blennies (Eleginops maclovinus)

Microplastics are one of the major environmental issues that need to be addressed because they are starting to impact food chains and are also affecting human populations. The size, colour, form, and abundance of microplastics in young blennies of the species Eleginops maclovinus were examined in the current study. While the stomach contents of 70 % of the studied individuals contained microplastics, 95 % of them included fibres. Individual size and the largest particle size that can be eaten, which ranges between 0.09 and 1.5 mm present no statistical correlation. The quantity of particles taken in by each individual does not change with size. The most present microfibers colours were blue and red. Sampled fibres were analysed with FT-IR and no natural fibres were detected, proving the synthetic origin of the detected particles. These findings suggest that protected coastlines create conditions that favour the encounter of microplastics increasing local wildlife exposure to microplastics, raising the danger of their ingestion with potential physiological, ecological, economical and human health consequences.

Earthworm activity effectively mitigated the negative impact of microplastics on maize growth

Microplastic pollution can have detrimental effects on soil environments and inhibit crop growth. Earthworms, known as soil engineers, promote crop growth, but their role and impact on the amelioration of microplastic-polluted soil is not yet clear. In this study, we investigated the impact and pathways of earthworm activity on microplastic-contaminated soil by introducing varying densities (without earthworm:0, low-density: 1, medium-density: 2, high-density: 5 ind column-1) of earthworms (epi-endogeic) into soil contaminated with two types of microplastics: polyethylene and polyvinyl chloride. Our results showed that earthworms all survived in soil polluted with two types of microplastics. Meanwhile, earthworm activity increased nutrient content and enzyme activity by 0.2-36.1% and 2.9-34.3%, respectively, and significantly increased soil microbial biomass and community diversity index. Earthworm activity also decreased antioxidant enzyme activity and promoted maize plant growth, including agronomic traits such as plant height, biomass, root length, and root surface area. Furthermore, the nutrient content of maize organs increased by 1.1-29.7%. Partial least squares models confirmed that earthworm activity alleviated the stress effect of microplastic pollution on plant growth by improving soil structure, fertility, and microbial abundance and diversity. The greatest effect on maize growth was observed with the improvement of soil physical-chemical properties. Our results suggest that medium densities of earthworms have the greatest soil improvement effect and provide an important basis for bioremediation of farmland contaminated by microplastics and promoting green and efficient development in agriculture.

Microplastic in mangroves: A worldwide review of contamination in biotic and abiotic matrices

This review presents the spatial distribution (where) and the methods applied (how) in assessing Microplastics (MPs) contamination in sediments, water, and organisms in mangrove areas. We analyzed 53 articles on MPs in Asia, America, and Africa and produced by 359 authors, although very localized, lacking wide-scale coverage of mangrove coasts around the world. The results showed that most of studies provided MP's bulk characteristics (type, size, color, form), along with global gross reserves of MPs in the mangrove compartments. Investigations in mangrove areas are still relatively limited. Therefore, for future research, it is relevant to enhance spatial and temporal sampling of MP contamination and to establish standardized protocols to enable effective comparisons between mangrove areas, rivers, beaches, and coastal seas. In addition, it is crucial to investigate the role of MPs as carriers or vectors of other pollutants.

Anthropogenic particles in the muscle, gill, and gastrointestinal tract of marine fish sold for human consumption

Contamination of marine fish with the widespread distribution of anthropogenic particles (APs) becomes increasingly severe, however, related research on the assessment of the occurrence of APs in the edible tissue of commercial fish is scarce. The objective of this study was to evaluate the features of APs pollution based on seven species of commercial marine fish (n = 12 per species) and investigate the accumulation of APs in different tissues of fish namely gill and gastrointestinal tract (GIT), and muscle. The results show that a total of 62 APs were detected in 33 out of 84 (39.3%) fresh fish samples using a micro-Raman spectrometer which in particular is characterized by a blue color, shape-like fiber, and size smaller than 0.5 mm. Among them, 47 (75.8%) particles were identified as pigments such as indigo, chrome yellow-orange, disperse yellow, and pigment black. The other 11 (17.7%) particles were plastic including polypropylene (PP), polyethylene terephthalate (PET), and polyacrylonitrile (PAN). And the rest 4 (6.5%) particles were anthropogenic cellulose fibers. Muscle tissue from six species of fish was detected to contain a total of 15 APs. Based on the total mean of APs found in fish muscle (0.018 AP items/g tissue) and on the consumption of fish in Malaysia (59 kg/capita/year), the estimated human intake of APs through fish consumption was 1062 AP items/year/capita. Considering that food consumption is an important route of human exposure to APs, it is suggested to add APs testing into the guidelines of food safety management systems and adopt mitigation measures to reduce the APs pollution in food.

Response of moulting genes and gut microbiome to nano-plastics and copper in juvenile horseshoe crab Tachypleus tridentatus

Nanoplastics (NPs) and heavy metals are typical marine pollutants, affecting the gut microbiota composition and molting rate of marine organisms. Currently, there is a lack of research on the toxicological effects of combined exposure to horseshoe crabs. In this study, we investigated the effects of NPs and copper on the expression of molt-related genes and gut microbiome in juvenile tri-spine horseshoe crabs Tachypleus tridentatus by exposing them to NPs (100 nm, 104 particles L-1) and/or Cu2+ (10 μgL-1) in seawater for 21 days. Compared with the control group, the relative mRNA expression of ecdysone receptor (EcR), retinoid x receptor (RXR), calmodulin-A-like isoform X1 (CaM X1), and heat shock 70 kDa protein (Hsp70) were significantly increased under the combined stress of NPs and Cu2+. There were no significant differences in the diversity and abundance indices of the gut microbial population of horseshoe crabs between the NPs and/or Cu2+ groups and the control group. According to linear discriminant analysis, Oleobacillus was the most abundant microorganism in the NPs and Cu2+ stress groups. These results indicate that exposure to either NPs stress alone or combined NPs and Cu2+ stress can promote the expression levels of juvenile molting genes. NPs exposure has a greater impact on the gut microbial community structure of juvenile horseshoe crabs compared to Cu2+ exposure. This study is helpful for predicting the growth and development of horseshoe crabs under complex environmental pollution.

From oceans to dinner plates: The impact of microplastics on human health

Microplastics, measuring less than 5 mm in diameter, are now found in various environmental media, including soil, water, and air, and have infiltrated the food chain, ultimately becoming a part of the human diet. This study offers a comprehensive examination of the intricate nexus between microplastics and human health, thereby contributing to the existing knowledge on the subject. Sources of microplastics, including microfibers from textiles, personal care products, and wastewater treatment plants, among others, were assessed. The study meticulously examined the diverse routes of microplastic exposure-ingestion, inhalation, and dermal contact-offering insights into the associated health risks. Notably, ingestion of microplastics has been linked to gastrointestinal disturbances, endocrine disruption, and the potential transmission of pathogenic bacteria. Inhalation of airborne microplastics emerges as a critical concern, with possible implications for respiratory and cardiovascular health. Dermal contact, although less explored, raises the prospect of skin irritation and allergic reactions. The impacts of COVID-19 on microplastic pollution were also highlighted. Throughout the manuscript, the need for a deeper mechanistic understanding of microplastic interactions with human systems is emphasized, underscoring the urgency for further research and public awareness.

Effects of virgin and BaP-adsorbed microplastics ingestion by Manila clams (Ruditapes philippinarum)

Numerous microplastic-related studies have investigated the impact of plastic materials on the marine food chain. In this study, Manila clams were exposed to microplastic (MP) of various polymer types, shapes, and concentrations to determine the ingestion selectivity and adverse effects caused. Benzo[a]pyrene was introduced as the second stressor to investigate the role of MP as a vector of contaminant. The result of a 2-day acute exposure showed that clams are more likely to ingest those in sphere shapes due to their similarity to microalgae. The feeding rate continuously declined when clams were exposed to at least 2to/L particles. Additionally, co-exposure of MP and B[a]P resulted in higher DNA fragmentation but lower catalase activity compared to single exposure to MP. Our study revealed that the uptake of MP by clams is not only determined by its shape and concentration but also by the presence of existing contaminants.

Nanoplastics released from daily used silicone and latex products during mechanical breakdown

Waste of polymer products, especially plastics, in nature has become a problem that caught the awareness of the general public during the last decade. The macro- and micro polymers in nature will be broken down by naturally occurring events such as mechanical wear and ultra-violet (UV) radiation which will result in the generation of polymeric particles in the nano-size range. We have recently shown that polystyrene and high-density polyethylene macroplastic can be broken down into nano-sized particles by applying mechanical force from an immersion blender. In this article, we show that particles in the nano-size range are released from silicone and latex pacifiers after the same treatment. Additionally, boiling the pacifiers prior to the mechanical breakdown process results in an increased number of particles released from the silicone but not the latex pacifier. Particles from the latex pacifier are acutely toxic to the freshwater filter feeding zooplankter Daphnia magna.

A Hidden Pathway for Human Exposure to Micro- and Nanoplastics-The Mechanical Fragmentation of Plastic Products during Daily Use

In numerous environmental compartments around the world, the existence of micro- and nanoplastics (MNPs) in the environment has been verified. A growing number of studies have looked at the interaction between MNPs and human activities due to the risks they may pose to humans. Exposure pathways are key factors in measuring MNPs risks. However, current research largely ignores the contribution of mechanical fragmentation pathways to MNPs exposure during the daily use of plastic products. Our critical review demonstrated the research gap between MNP fragmentation and risk assessments via a network analysis. The release of fragmented MNPs and their properties were also described at various scales, with emphasis on environmental stressors and mechanical fragmentation. In the scenarios of daily use, plastic products such as food packaging and clothing provide acute pathways of MNPs exposure. The release tendency of those products (up to 102 mg MNPs) are several orders of magnitude higher than MNPs abundances in natural compartments. Despite the limited evidence available, waste recycling, landfill and municipal activities represented long-term pathways for MNPs fragmentation and point sources of MNPs pollution in environmental media. Assessing the health effects of the fragmentation process, unfortunately, is further hampered by the current absence of human exposure impact assessments for secondary MNPs. We proposed that future studies should integrate aging evaluation into risk assessment frameworks and establish early warning signs of MNPs released from plastic products.

Microplastics, a Global Issue: Human Exposure through Environmental and Dietary Sources

Plastic production has grown dramatically over the years. Microplastics (MPs) are formed from the fragmentation of larger plastic debris by combining chemical, physical, and biological processes and can degrade further to form nanoplastics (NPs). Because of their size, MPs and NPs are bioavailable to many organisms and can reach humans through transport along the food chain. In addition to the risk from ingesting MPs themselves, there are risks associated with the substances they carry, such as pesticides, pathogenic microorganisms, and heavy metals, and with the additives added to plastics to improve their characteristics. In addition, bioaccumulation and biomagnification can cause a cumulative exposure effect for organisms at the top of the food chain and humans. Despite the growing scientific interest in this emerging contaminant, the potential adverse effects remain unclear. The aim of this review is to summarize the characteristics (size, shape, color, and properties) of MPs in the environment, the primary sources, and the transport pathways in various environmental compartments, and to shed more light on the ecological impact of MPs and the potential health effects on organisms and humans by identifying human exposure pathways.

Microplastics in the Lung Tissues Associated with Blood Test Index

Microplastics (MPs) have received a lot of attention and have been detected in multiple environmental matrices as a new environmental hazard, but studies on human internal exposure to MPs are limited. Here, we collected lung tissue samples from 12 nonsmoking patients to evaluate the characteristics of MPs in human lung tissues using an Agilent 8700 laser infrared imaging spectrometer and scanning electron microscopy. We detected 108 MPs covering 12 types in the lung tissue samples, with a median concentration of 2.19 particles/g. Most of the MPs (88.89%) were sized between 20 to 100 μm. Polypropylene accounts for 34.26% of the MPs in the lung tissues, followed by polyethylene terephthalate (21.30%) and polystyrene (8.33%). Compared with males and those living far from a major road (≥300 m), females and those living near the main road (<300 m) had higher levels of MPs in lung tissues, which positively correlated with platelet (PLT), thrombocytocrit, fibrinogen (FIB), and negatively related with direct bilirubin (DB). These findings help confirm the presence in the respiratory system and suggest the potential sources and health effects of inhaled MPs.

Global hotspots and trends in interactions of microplastics and heavy metals: a bibliometric analysis and literature review

Microplastics (MPs) are identified as emerging contaminants; however, their interactions with heavy metals in the environment have not been well elucidated. Here, the research progress, hotspots, and trends in the interactions of MPs and heavy metals were analyzed at a global scale using a bibliometric analysis combined with a literature review. We comprehensively searched the Web of Science Core Collection database from 2008 to July 5, 2022. A total of 552 articles published in 124 journals were selected, which came from 70 countries and 841 institutions. The most contributing journals, countries, institutions, and authors were identified. Visualization methods were used to identify high co-citation references and hot keywords in the 552 articles. Evolutionary and cluster analyses of hot keywords suggested several research hotspots in the co-contamination of MPs and heavy metals, including their toxicity and bioaccumulation, the adsorption and desorption behaviors, the environmental pollution and risk assessment, and their detection and characterization. Based on the current research status, several directions of priority are recommended to understand the interactions between MPs and heavy metals and their potential risks. This article can help recognize the current research status and future directions in this field.

The extent of microplastic pollution along the eastern coast of India: Focussing on marine waters, beach sand, and fish

In this study, for the first time, we evaluated microplastic contamination in water, beach sand, and fish samples collected from the seven most famous and crowded beaches of the eastern coast of India, which cover around 1200 km. The average number of microplastics found was 80 ± 33 microplastics/m3 and 4 ± 2 microplastics/kg dry weight with a numerical abundance of polyethylene and polystyrene for water and sand samples, respectively. The polymer hazard index score, which represents the severity of the microplastics scenario in the studied locations, depicts that this coastline falls under hazard levels IV and V (most hazardous) for water and sand samples, respectively. The study revealed that approximately 30 % of the commercially important fishes collected from the locations contained microplastics with polyethylene terephthalate and polypropylene being the most abundant types. Rastrelliger kanagurta and Sardinella gibbosa were identified as the most polluted species.

The impact of microplastics on bivalve mollusks: A bibliometric and scientific review

Bivalves are important members of the ecosystem and their populations are declining globally, making them a concern for their role in ecosystem services and the fishing industry. Bivalves are excellent bioindicators of MPs pollution due to their widespread distribution, filtering capabilities, and close association with human health. Microplastics (MPs) have direct and indirect impacts on bivalves, affecting their physiology, habitat structure, food sources, and persistence of organic pollutants. This review provides an extensive overview of the impact of MPs on bivalves, covering various aspects such as their economic significance, ecological roles, and importance in biomonitoring environmental quality. The article presents the current state of knowledge on the sources and pathways of MPs in aquatic environments and their effects on bivalves. The mechanisms underlying the effects of MPs on bivalves, including ingestion, filtration activity, feeding inhibition, accumulation, bioaccumulation, and reproduction, are also discussed. Additionally, a bibliometric analysis of research on MPs in bivalves is presented, highlighting the number of papers, geographical distribution, and keyword clusters relating to MPs. Finally, the review emphasizes the importance of ongoing research and the development of mitigation strategies to reduce the negative effects of MPs pollution on bivalves and their habitats in oceans and coastal waters.

Do loggerhead sea turtle (Caretta caretta) gut contents reflect the types, colors and sources of plastic pollution in the Southwest Indian Ocean?

We analyzed plastic debris ingested by loggerheads from bycatch between 2007 and 2021 in the Southwest Indian Ocean (SWIO). We also analyzed plastic debris accumulated on beaches of the east coast of Madagascar as a proxy for ocean plastics to compare the characteristics of beached plastics and plastic ingested by turtles. We conducted a "brand audit" of the plastics to determine their country of origin. An oceanic circulation model was used to identify the most likely sources of plastics in the SWIO. In total, 202 of the 266 loggerheads analyzed had ingested plastics. Plastics categorized as "hard" and "white" were equally dominant in loggerheads and on beaches, suggesting no diet selectivity. Both the brand audit and circulation modeling demonstrated that Southeast Asia is the main source of plastic pollution in the region. This study demonstrates that loggerheads can be used as bioindicators of plastic pollution in the SWIO.

Internal Defense System of Mytilus galloprovincialis (Lamarck, 1819): Ecological Role of Hemocytes as Biomarkers for Thiacloprid and Benzo[a]Pyrene Pollution

The introduction of pollutants, such as thiacloprid and benzo[a]pyrene (B[a]P), into the waters of urbanized coastal and estuarine areas through fossil fuel spills, domestic and industrial waste discharges, atmospheric inputs, and continental runoff poses a major threat to the fauna and flora of the aquatic environment and can have a significant impact on the internal defense system of invertebrates such as mussels. Using monoclonal and polyclonal anti-Toll-like receptor 2 (TLR2) and anti-inducible nitric oxide synthetase (iNOS) antibodies for the first time, this work aims to examine hemocytes in the mantle and gills of M. galloprovincialis as biomarkers of thiacloprid and B[a]P pollution and analyze their potential synergistic effect. To pursue this objective, samples were exposed to the pollutants, both individually and simultaneously. Subsequently, oxidative stress biomarkers were evaluated by enzymatic analysis, while tissue changes and the number of hemocytes in the different contaminated groups were assessed via histomorphological and immunohistochemical analyses. Our findings revealed that in comparison to a single exposure, the two pollutants together significantly elevated oxidative stress. Moreover, our data may potentially enhance knowledge on how TLR2 and iNOS work as part of the internal defense system of bivalves. This would help in creating new technologies and strategies, such as biosensors, that are more suitable for managing water pollution, and garnering new details on the condition of the marine ecosystem.