Effect of microplastics in water and aquatic systems

Polyethylene terephthalate waste derived nanomaterials (WDNMs) and its utilization in electrochemical devices

Plastics are a vital component of our daily lives in the contemporary globalization period; they are present in all facets of modern life. Because the bulk of synthetic plastics utilized in the market are non-biodegradable by nature, the issues associated with their contamination are unavoidable in an era dominated by polymers. Polyethylene terephthalate (PET), which is extensively used in industries such as automotive, packaging, textile, food, and beverages production represents a major share of these non-biodegradable polymer productions. Given its extensive application across various sectors, PET usage results in a considerable amount of post-consumer waste, majority of which require disposal after a certain period. However, the recycling of polymeric waste materials has emerged as a prominent topic in research, driven by growing environmental consciousness. Numerous studies indicate that products derived from polymeric waste can be converted into a new polymeric resource in diverse sectors, including organic coatings and regenerative medicine. This review aims to consolidate significant scientific literatures on the recycling PET waste for electrochemical device applications. It also highlights the current challenges in scaling up these processes for industrial application.

Microplastics in rocky shore mollusks of different feeding habits: An assessment of sentinel performance

Microplastics (MPs) accumulation in rocky shore organisms has limited knowledge. This study investigated MPs accumulation in filter-feeding oysters, herbivorous limpets and carnivorous snails to assess their performance as sentinel species in the MPs trophic transfer. The samples were obtained along a contamination gradient in the Santos Estuarine System, Brazil. All three studied species showed MPs concentrations related to the contamination gradient, being the oysters the species that showed the highest levels, followed by limpets and snails (average of less and most contaminated sites of 1.06-8.90, 2.28-5.69 and 0.44-2.10 MP g-1, respectively), suggesting that MPs ingestion rates are linked to feeding habits. MPs were mainly polystyrene and polyacetal. The polymer types did not vary among sites nor species. Despite minor differences in percentages and diversity of size, shape, and color classes, the analyzed species were equally able to demonstrate dominance of small, fiber, transparent, black and blue MPs. Thus, oysters, limpets, and snails are proposed as sentinels of MPs in monitoring assessments.

A realistic combined exposure scenario: effect of microplastics and atrazine on Piaractus mesopotamicus

Microplastics, considered emerging environmental contaminants resulting from plastic degradation, are discovered in diverse aquatic ecosystems and can be unintentionally ingested by fish. Therefore, it is essential to characterize their interaction with other contaminants, such as agrochemicals, in aquatic environments. This study aimed to assess histological, enzymatic, and genotoxic biomarkers in juvenile pacú (Piaractus mesopotamicus) exposed to polyethylene (PE) microplastic particles and the herbicide atrazine, individually or combined, for 15 days. Four treatments were used: a negative control (CON), PE in the fish diet (0.1% w/w, FPE), atrazine through water (100 μg L-1, ATZ), and the mixture (ATZ+FPE). Results confirmed histological alterations in gills (edema and lamellar fusion) and liver (necrotic areas and congestion) of fish exposed to ATZ and ATZ+FPE. The number of goblet cells increased in the posterior intestine of fish under ATZ+FPE compared to CON and FPE. Enzyme activities (CAT, GST, AChE, and BChE) significantly increased in ATZ+FPE compared to CON. However, no genotoxic effect was demonstrated. These findings provide insights into the complex impacts of simultaneous exposure to atrazine and microplastics, emphasizing the need for continued research to guide effective environmental management strategies against these contaminants that represent a risk to aquatic organisms.

Microplastic pollution in high-altitude Nainital lake, Uttarakhand, India

Microplastics (MPs) contamination has been reported in all environmental compartments, but very limited information is available at higher-altitude lakes. Nainital Lake, located at a high altitude in the Indian Himalayas, has various ecosystem services and is the major source of water for Nainital town, but the MP abundance is still unknown. This study presents the first evidence of the abundance and distribution of MP in Nainital Lake. Surface water and sediment samples were analysed from 16 different sites in and around the catchment area of Nainital Lake. The MP were observed in all the samples, and their abundance in surface water was 8.6-56.0 particles L-1 in the lake and 2.4-88.0 particles L-1 in hotspot sites. In the surface sediment, MP abundance ranged from 0.4-10.6 particles g-1, while in the hotspot sediment, the mean abundance was 0.6 ± 0.5 particles g-1. Fibers were the dominant MP, while 0.02-1 mm were the predominant size of MP particles. The results of chemical characterization showed the presence of six polymers, among which high-density polyethylene was the most abundant. The Polymer Hazard Index assessment classified the identified polymers as low-to high-risk categories, with a higher abundance of low- (polypropylene) and medium- (polyethylene)-risk polymers. Tourist activities and run-off catchments can be considered the major sources of MP, which can affect the ecosystem. Minimal concentrations of MP were observed in the tube well and drinking water, which depicts the direct risks to humans and, thus, the need for remedial measures to prevent MP contamination in drinking water. This study improves the knowledge of MP contamination in the higher-altitude freshwater lake, which can be the major pathway for the transport of MP to the rivers, and also emphasizes the need for waste management in Nainital town.

Assessment of dietary polyvinylchloride, polypropylene and polyethylene terephthalate exposure in Nile tilapia, Oreochromis niloticus: Bioaccumulation, and effects on behaviour, growth, hematology and histology

Microplastics (MPs) have been recognized as emerging aquatic pollutants receiving major concern due to their detrimental effects on aquatic life. Nile Tilapia, Oreochromis niloticus is a model species considered in toxicological studies to address the effects of pollutants in freshwater animals. However, comprehensive knowledge comparing the impacts on fish across various MPs polymers is scarce. Therefore, the overarching aim of the current study was to examine the bioconcentration of MPs polymers: polyvinylchloride (PVC), polypropylene (PP), and polyethylene terephthalate (PET), and their toxic effects on growth, and behavioral responses, hematology, and histology of gills, liver, and intestine in O. niloticus. Fishes were subjected to a 21-day dietary exposure to MPs by assigning them into six treatment groups: T1 (4% of PVC), T2 (4% of PP), T3 (4% of PET), T4 (8% of PVC), T5 (8% of PP), T6 (8% of PET), and control (0% of MPs), to assess the effects on fish across the polymers and dosage. Results showed several abnormalities in anatomical and behavioral parameters, lower growth, and high mortality in MPs-exposed fish, indicating a dose-dependent relationship. The elevated dosage of polymers raised the bioavailability of PVC, PP, and PET in gills and gut tissues. Noteworthy erythrocyte degeneration referred to cytotoxicity and stress imposed by MPs, whereas the alterations in hematological parameters were possibly due to blood cell damage, also indicating mechanisms of defense against MPs toxicity. Histopathological changes in the gills, liver, and intestine confirmed the degree of toxicity and associated dysfunctions in fish. A higher sensitivity of O. niloticus to PET-MPs compared to other polymers is likely due to its chemical properties and species-specific morphological and physiological characteristics. Overall, the present study reveals valuable insights into the emerging threat of MPs toxicity in freshwater species, which could be supportive of future toxicological research.

Identification and visualization of environmental microplastics by Raman imaging based on hyperspectral unmixing coupled machine learning

Microplastics (MPs) are ubiquitous contaminants that have become an emerging pollutant of concern, potentially threatening human health and ecosystem environments. Although current detection methods can accurately identify various types of MPs, it remains necessary to develop non-destructive and rapid methods to meet growing demands for detection. Herein, we combine a hyperspectral unmixing method and machine learning to analyse Raman imaging data of environmental MPs. Five MPs types including poly(butylene adipate-co-terephthalate) (PBAT), poly(butylene succinate) (PBS), p-polyethylene (PE), polystyrene (PS) and polypropylene (PP) were visualized and identified. Individual or mixed pure or aged MPs along with environmental samples were analysed by Raman imaging. Alternating volume maximization (AVmax) combined with unconstrained least squares (UCLS) method estimated end members and abundance maps of each of the MPs in the samples. Pearson correlation coefficients (r) were used as the evaluation index; the results showed that there is a high similarity between the raw spectra and the average spectra calculated by AVmax. This indicates that Raman imaging based on machine learning and hyperspectral unmixing is a novel imaging analysis method that can directly identify and visualize MPs in the environment.

Impact of anthropogenic activities on the abundance of microplastics in copepods sampled from the southeast coast of India

In recent year, the use of plastics has become inevitable due to its unique properties that allow for the production of durable and non-durable goods. Post use, plastics enter the waste stream and now can be found in all compartments of the biosphere as microplastics (MPs). This study presents the abundance of MPs in surface water and within copepods in the southwestern Bay of Bengal during dry (June 2022) and wet season (November 2022). The MPs in the surface water were found in all three regions [Chennai, Tuticorin and Nagapattinam (four locations in each region)] and maximum in wet season (53 particles/m3). Moreover, during dry season the mean ingestion of MPs by copepods in Chennai (0.103 ± 0.04 particles/individual), Tuticorin (0.11 ± 0.07 particles/individual) and Nagapattinam (0.036 ± 0.01 particles/individual) is high compared to the wet season. The maximum level of MPs found in both surface water and ingestion by copepods in Tuticorin and Chennai is subjective to the high maritime activities than Nagapattinam region. Whatever, the anthropogenic activities in the study region increase the bioavailability of MPs pollutant in the copepods and transported to higher trophic levels, endangering marine life and human health. Hence, further studies are needed to determine their potential impact on marine food chain in this alarming situation.

Naturally manufactured biochar materials based sensor electrode for the electrochemical detection of polystyrene microplastics

In recent times, microplastics have become a disturbance to both aquatic and terrestrial ecosystems and the ingestion of these particles can have severe consequences for wildlife, aquatic organisms, and even humans. In this study, two types of biochars were manufactured through the carbonization of naturally found starfish (SF-1) and aloevera (AL-1). The produced biochars were utilized as sensing electrode materials for the electrochemical detection of ∼100 nm polystyrene microplastics (PS). SF-1 and AL-1 based biochars were thoroughly analyzed in terms of morphology, structure, and composition. The detection of microplastics over biochar based electrodes was carried out by electrochemical studies. From electrochemical results, SF-1 based electrode exhibited the detection efficiency of ∼0.2562 μA/μM∙cm2 with detection limit of ∼0.44 nM whereas, a high detection efficiency of ∼3.263 μA/μM∙cm2 was shown by AL-1 based electrode and detection limit of ∼0.52 nM for PS (100 nm) microplastics. Process contributed to enhancing the sensitivity of AL-1 based electrode might associate to the presence of metal-carbon framework over biochar's surfaces. The AL-1 biochar electrode demonstrated excellent repeatability and detection stability for PS microplastics, suggesting the promising potential of AL-1 biochar for electrochemical microplastics detection.

Comparison of benzotriazole ultraviolet stabilizers (BUVs) removal from wastewater after subsequent stages of sequencing batch reactor (SBR) treatment process

The research focused on benzotriazole ultraviolet stabilizers (BUVs) which are commonly used compounds despite being found dangerous, e.g. promoting breast cancer cell proliferation, damaging vital organs such as hearts, brains livers and kidneys. The aim of the study was to analyse the efficiency and removal rate of BUVs from wastewater depending on the quantity of tested compounds and SBR anaerobic-aerobic conditions. The study was conducted in sequencing batch reactors (SBRs - 17 L) with real flocculent activated sludge (8 L) and model wastewater (5 L) containing UV-326, UV-327, UV-328, UV-329 and UV-P from 50 to 600 μg∙L-1. The SBR were operated in 390 cycles of 7 h and 10 min over 130 days. The similarity of the technological parameters of the treatment process to those used in a real wastewater treatment plant was maintained. Efficiency removal of individual BUVs was strictly dependent on the dose of compounds introduced into wastewater and ranged from 68.2 to 97 %. Removal of UV-329 occurred with lowest efficiency (from 68.2 to 85.2 %) while UV-326 was most efficiently removed from the wastewater (from 94.1 to 97 %). UV-329 was removed from wastewater with the lowest (0.0968-0.9524 μg∙L-1∙min-1) average removal rate while UV-327 with the highest (0.16-1.3357 μg∙L-1∙min-1), irrespective of BUVs dose in the influent. Secondary release of BUVs into the wastewater occurred in SBR during the settling phase and was dependent on the type and concentration of the BUVs in the raw wastewater. This occurrence was noted for UV-326 ≥ 100; UV-327 = 600; UV-328 ≥ 200; UV-329 ≥ 50 and UV-P ≥ 100 μg∙L-1. The settling phase needs to be shortened to the required minimum. This is an important conclusion for WWTPs in regards to SBR cycle duration and technological parameters of the treatment process.

An identification of optimal waste disposal method for dumpsite remediation using the Fermatean fuzzy multi-criteria decision-making method

Improperly managed wastes that have been dumped in landfills over the years pose various challenges, but they also offer potential benefits. The feasibility of recycling such waste depends on the type of wastes, the condition of dumpsites, and the technology implemented for disposal. The selection of an alternative waste disposal method from the many available options for dumpsite remediation is a complex decision-making process among experts. The primary aim of this study is to assist in an extended multi-criteria decision-making (MCDM) method to reduce complexity in the proposed dumpsite remediation problem influenced by multiple criteria and to identify the optimal waste disposal method. Data uncertainties are managed with the proposed Fermatean fuzzy preference scale, and the importance of all socio-economic criteria is assessed using the full consistency method (FUCOM). The final ranking results of the weighted aggregated sum product assessment (WASPAS) method identify that the Waste-to-Energy (WtE) process could play a significant role in the disposal of land-filled unprocessed wastes, promoting sustainable waste management. Meanwhile, the methodology explores the idea that financial and logistical constraints may limit the feasibility of large-scale recycling efforts. This combination of environmental science and decision science addresses real-world challenges, helping municipal solid waste management authorities implement sustainable waste management practices.

Microplastics and associated chemicals in drinking water: A review of their occurrence and human health implications

Microplastics (MPs) have entered drinking water (DW) via various pathways, raising concerns about their potential health impacts. This study provides a comprehensive review of MP-associated chemicals, such as oligomers, plasticizers, stabilizers, and ultraviolet (UV) filters that can be leached out during DW treatment and distribution. The leaching of these chemicals is influenced by various environmental and operating factors, with three major ones identified: MP concentration and polymer type, pH, and contact time. The leaching process is substantially enhanced during the disinfection step of DW treatment, due to ultraviolet light and/or disinfectant-triggered reactions. The study also reviewed human exposure to MPs and associated chemicals in DW, as well as their health impacts on the human nervous, digestive, reproductive, and hepatic systems, especially the neuroendocrine toxicity of endocrine-disrupting chemicals. An overview of MPs in DW, including tap water and bottled water, was also presented to enable a background understanding of MPs-associated chemicals. In short, certain chemicals leached from MPs in DW can have significant implications for human health and demand further research on their long-term health impacts, mitigation strategies, and interactions with other pollutants such as disinfection byproducts (DBPs) and per- and polyfluoroalkyl substances (PFASs). This study is anticipated to facilitate the research and management of MPs in DW and beverages.

Micro/nanoplastics: Critical review of their impacts on plants, interactions with other contaminants (antibiotics, heavy metals, and polycyclic aromatic hydrocarbons), and management strategies

Microplastic/nanoplastics (MPs/NPs) contamination is not only emerging threat to the agricultural system but also constitute global hazard to the environment worldwide. Recent review articles have addressed the environmental distribution of MPs/NPs and their single-exposure phytotoxicity in various plant species. However, the mechanisms of MPs/NPs-induced phytotoxicity in conjunction with that of other contaminants remain unknown, and there is a need for strategies to ameliorate such phytotoxicity. To address this, we comprehensively review the sources of MPs/NPs, their uptake by and effects on various plant species, and their phytotoxicity in conjunction with antibiotics, heavy metals, polycyclic aromatic hydrocarbons (PAHs), and other toxicants. We examine mechanisms to ameliorate MP/NP-induced phytotoxicity, including the use of phytohormones, biochar, and other plant-growth regulators. We discuss the effects of MPs/NPs -induced phytotoxicity in terms of its ability to inhibit plant growth and photosynthesis, disrupt nutrient metabolism, inhibit seed germination, promote oxidative stress, alter the antioxidant defense system, and induce genotoxicity. This review summarizes the novel strategies for mitigating MPs/NPs phytotoxicity, presents recent advances, and highlights research gaps, providing a foundation for future studies aimed at overcoming the emerging problem of MPs/NPs phytotoxicity in edible crops.

Intracellular Protein Adsorption Behavior and Biological Effects of Polystyrene Nanoplastics in THP-1 Cells

Micro(nano)plastics (MNPs) are emerging pollutants that can adsorb pollutants in the environment and biological molecules and ultimately affect human health. However, the aspects of adsorption of intracellular proteins onto MNPs and its biological effects in cells have not been investigated to date. The present study revealed that 100 nm polystyrene nanoplastics (NPs) could be internalized by THP-1 cells and specifically adsorbed intracellular proteins. In total, 773 proteins adsorbed onto NPs with high reliability were identified using the proteomics approach and analyzed via bioinformatics to predict the route and distribution of NPs following cellular internalization. The representative proteins identified via the Kyoto Encyclopedia of Genes and Genomes pathway analysis were further investigated to characterize protein adsorption onto NPs and its biological effects. The analysis revealed that NPs affect glycolysis through pyruvate kinase M (PKM) adsorption, trigger the unfolded protein response through the adsorption of ribophorin 1 (RPN1) and heat shock 70 protein 8 (HSPA8), and are chiefly internalized into cells through clathrin-mediated endocytosis with concomitant clathrin heavy chain (CLTC) adsorption. Therefore, this work provides new insights and research strategies for the study of the biological effects caused by NPs.

Ferroptosis Induced by Pollutants: An Emerging Mechanism in Environmental Toxicology

Environmental pollutants have been recognized for their ability to induce various adverse outcomes in both the environment and human health, including inflammation, apoptosis, necrosis, pyroptosis, and autophagy. Understanding these biological mechanisms has played a crucial role in risk assessment and management efforts. However, the recent identification of ferroptosis as a form of programmed cell death has emerged as a critical mechanism underlying pollutant-induced toxicity. Numerous studies have demonstrated that fine particulates, heavy metals, and organic substances can trigger ferroptosis, which is closely intertwined with lipid, iron, and amino acid metabolism. Given the growing evidence linking ferroptosis to severe diseases such as heart failure, chronic obstructive pulmonary disease, liver injury, Parkinson's disease, Alzheimer's disease, and cancer, it is imperative to investigate the role of pollutant-induced ferroptosis. In this review, we comprehensively analyze various pollutant-induced ferroptosis pathways and intricate signaling molecules and elucidate their integration into the driving and braking axes. Furthermore, we discuss the potential hazards associated with pollutant-induced ferroptosis in various organs and four representative animal models. Finally, we provide an outlook on future research directions and strategies aimed at preventing pollutant-induced ferroptosis. By enhancing our understanding of this novel form of cell death and developing effective preventive measures, we can mitigate the adverse effects of environmental pollutants and safeguard human and environmental health.

Sunscreens and micro(nano)plastics: Are we aware of these threats to the Egyptian coral reefs?

During a snorkeling trip to Marsa Alam and Hamata (southern Red Sea Riviera, Egypt) I explored the coral reefs and the diverse marine habitats of fish and invertebrate species. The area invites recreational diving and snorkeling, but the beaches are littered with all sorts of solid waste (mainly fragmented plastics). Also, there are no local restrictions on sunscreen use. The development of tourism to the area raises questions about the environmental impact and how its further growth will have on coral reefs. Every year, 1.2 million tourists visit the Red Sea coast (about 3287 tourists per day) and release about 1.7 tons/month of sunscreen into the Red Sea. As an ecologist and editorial board member of Science of the Total Environment, I ask myself how we as scientists can increase public awareness and call for prompt actions to protect the coral reefs. The discussion underlines two major threats to the Egyptian coral reefs: sunscreen use and micro(nano)plastics waste. The discussion closes with possible solutions, future perspectives, and recommendations to protect the coral reefs ecosystem of the Egyptian Red Sea.

Combined experimental and molecular dynamics removal processes of contaminant phenol from simulated wastewater by polyethylene terephthalate microplastics

Microplastics (MPs) and phenolics are pollutants found ubiquitously in freshwater systems. MPs oftentimes serve as a vector for pollutants across ecosystems and are now being explored as alternative adsorbents for pollutant removal. This strategy would reflect the 'reuse' of an existing waste stream into a potentially useful product while at the same time helping to minimize plastic waste in the marine environment. In this study, the adsorption of phenol onto pristine (Pr-PET), modified (Mod-PET), and aged (Ag-PET) Polyethylene Terephthalate (PET) microplastics was examined experimentally and theoretically. Kinetics, isotherms, and thermodynamics models were used to investigate the adsorption process while Grand Canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations were employed to investigate molecular level alterations. The result showed that the Ag-PET MPs had the best removal efficiency due larger surface area and the adsorption occurred in a pseudo-second-order manner, showing that the rate of phenol adsorption is directly proportional to the number of surface-active sites on the surface of PET MPs while the intraparticle diffusion defined rate-limiting step. However, the maximum monolayer adsorption capacity followed Mod-PET (38.02 mg/g) > Ag-PET (8.08 mg/g) > Pr-PET (6.84 mg/g). The adsorption process proceeded spontaneously and thermodynamically favourable. GCMC-MD simulations revealed that PET MPs are capable of successfully adsorbing the phenol molecule through Van der Waals and electrostatic interactions and can be adopted as novel adsorbents for phenol removal in aqueous solutions.

Mitigating microplastic pollution: A critical review on the effects, remediation, and utilization strategies of microplastics

Microplastics are found ubiquitous in the natural environment and are an increasing source of worry for global health. Rapid industrialization and inappropriate plastic waste management in our daily lives have resulted in an increase in the amount of microplastics in the ecosystem. Microplastics that are <150 μm in size could be easily ingested by living beings and cause considerable toxicity. Microplastics can aggregate in living organisms and cause acute, chronic, carcinogenic, developmental, and genotoxic damage. As a result, a sustainable approach to reducing, reusing, and recycling plastic waste is required to manage microplastic pollution in the environment. However, there is still a significant lack of effective methods for managing these pollutants. As a result, the purpose of this review is to convey information on microplastic toxicity and management practices that may aid in the reduction of microplastic pollution. This review further insights on how plastic trash could be converted as value-added products, reducing the load of accumulating plastic wastes in the environment, and leading to a beneficial endeavor for humanity.

Interactions between microplastics and Culex sp. larvae in wastewater

Microplastics (MPs) are a growing issue because they endanger both aquatic organisms and humans. Studies have indicated that wastewater treatment plants (WWTPs) are one of the major contributors to MPs in the environment. However, studies on the abundance of MP contamination in WWTPs and its transmission into aquatic organisms are still scarce, especially in Egypt. The goal of this study was to examine the temporal fluctuations in the distribution of MPs in surface water and the dominant macroinvertebrate fauna (Culex sp. larvae) in a fixed wastewater basin in Sohag Governorate, Egypt. The average of MPs in the surface water was 3.01 ± 0.9 particles/L. The results indicated to seasonal variation of MP abundance in the wastewater basin that was significantly higher in winter than in the other seasons. The risk index for polymers (H), pollution load index (PLI), and potential ecological risk index (RI) were used to assess the degree of MP contamination. The basin has moderate H values (<1000) because of the presence of polymers with moderate hazard scores such as polyester (PES), polyethylene (PE), and polypropylene (PP). According to the PLI values, surface water is extremely contaminated with MPs (PLI: 88 to 120). The RI values of surface water showed higher ecological risk (level V). MPs in Culex sp. larvae were seasonally changed with an 85% detection rate, and an abundance average of 0.24 ± 0.65 particles/ind, MP concentration in Culex sp. larvae was influenced by the MP characters (shape, color, and polymer). The larvae of Culex sp. showed a greater preference for black and red fibrous polyester (PES) with sizes (<1000 μm) of MPs. These findings suggest that Culex sp. larvae prefer ingesting MPs that resemble their food. It is possible to overestimate Culex sp.'s preference for lower sizes because of their catabolism of MPs. To better understand the preferences of Culex sp. larvae for MPs, further controlled trials should be conducted. PRACTITIONER POINTS: Wastewater is highly contaminated with microplastics (MPs) in the different seasons. First report of detection of the seasonal abundance of MP in Culex sp. larvae. Culex sp. larvae showed a stronger feeding preference for MPs with specific characteristics. Smaller size and blue polyester fibers were the dominant characteristics of MPs in wastewater.

PFAS: exploration of neurotoxicity and environmental impact

Per- and polyfluoroalkyl substances (PFAS) are widespread contaminants stemming from various industrial and consumer products, posing a grave threat to both human health and ecosystems. PFAS contamination arises from multiple sources, including industrial effluents, packaging, and product manufacturing, accumulating in plants and impacting the food chain. Elevated PFAS levels in water bodies pose significant risks to human consumption. This review focuses on PFAS-induced neurological effects, highlighting disrupted dopamine signalling and structural neuron changes in humans. Animal studies reveal apoptosis and hippocampus dysfunction, resulting in memory loss and spatial learning issues. The review introduces the BKMR model, a machine learning technique, to decipher intricate PFAS-neurotoxicity relationships. Epidemiological data underscores the vulnerability of young brains to PFAS exposure, necessitating further research. Stricter regulations, industry monitoring, and responsible waste management are crucial steps to reduce PFAS exposure.

Effect of microplastics deposition on human lung airways: A review with computational benefits and challenges

Microplastics have become omnipresent in the environment, including the air we inhale, the water we consume, and the food we eat. Despite limited research, the accumulation of microplastics within the human respiratory system has garnered considerable interest because of its potential implications for health. This review offers a comprehensive examination of the impacts stemming from the accumulation of microplastics on human lung airways and explores the computational benefits and challenges associated with studying this phenomenon. The existence of microplastics in the respiratory system can lead to a range of adverse effects. Research has indicated that microplastics can induce inflammation, oxidative stress, and impaired lung function. Furthermore, the small size of microplastics allows them to penetrate deep into the lungs, reaching the alveoli, where gas exchange takes place. This raises concerns about long-term health consequences, such as the development of respiratory diseases and the potential for translocation to other organs. Computational approaches have been instrumental in understanding the impact of microplastic deposition on human lung airways. Computational models and simulations enable the investigation of particle dynamics, deposition patterns, and interaction mechanisms at various levels of complexity. However, studying microplastics in the lung airways using computational methods presents several challenges. The complex anatomy and physiological processes of the respiratory system require accurate representation in computational models. Obtaining relevant data for model validation and parameterization remains a significant hurdle. Additionally, the diverse nature of microplastics, including variations in size, shape, and chemical composition, poses challenges in capturing their full range of behaviours and potential toxicological effects.

Advances in identifying and managing emerging contaminants in aquatic ecosystems: Analytical approaches, toxicity assessment, transformation pathways, environmental fate, and remediation strategies

Emerging contaminants (ECs) are increasingly recognized as threats to human health and ecosystems. This review evaluates advanced analytical methods, particularly mass spectrometry, for detecting ECs and understanding their toxicity, transformation pathways, and environmental distribution. Our findings underscore the reliability of current techniques and the potential of upcoming methods. The adverse effects of ECs on aquatic life necessitate both in vitro and in vivo toxicity assessments. Evaluating the distribution and degradation of ECs reveals that they undergo physical, chemical, and biological transformations. Remediation strategies such as advanced oxidation, adsorption, and membrane bioreactors effectively treat EC-contaminated waters, with combinations of these techniques showing the highest efficacy. To minimize the impact of ECs, a proactive approach involving monitoring, regulations, and public education is vital. Future research should prioritize the refining of detection methods and formulation of robust policies for EC management.

Environmental impacts of 5-year plastic waste deposition on municipal waste landfills: A follow-up study

Depositing plastic waste has long been a prevalent method of utilization, persisting today. Plastic waste within municipal waste landfills (MWL) undergoes diverse (bio-)degradation processes, which may be a potential source of chemicals and microorganisms harmful to the environment and human health. Soil and air samples were collected from modern MWL to identify environmental contamination caused by 5 years of plastic (bio-)degradation. The pH of soil samples was higher than in the reference area (RA), which was possibly caused by alterations in soil anionic composition detected with ion chromatography. The presence of plastic additives with a toxic potential was detected in soil samples by gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). With the use of thermal desorption and GC - MS, hazardous substances (phthalic anhydride, phenylmaleic anhydride, ethylbenzene, xylene) with a known impact on the human endocrine system were also detected. The number of microorganisms, both fungi, and bacteria, was highly increased in soil and air in the MWL as compared to the RA. The soil collected in the MWL area appeared to be phytotoxic, and inhibited seed germination (Phytotoxkit FTM bioassay), while acute toxicity Microtox® bioassay showed a hormetic effect towards Aliivibrio fischeri. Obtained results exhibited massive soil and air contamination, with both chemical substances and microorganisms while plastic waste undergoes (bio-)degradation. It may contribute to serious environmental contamination and pose a threat to human health.

Exploring the microplastic pollution: Unveiling origins and varieties in coastal sediments and waters of the Bushehr Province, Persian Gulf, Iran

In this study, microplastic (MP) pollution in the coastal sediments and tidal waters of Bushehr province in the Persian Gulf was comprehensively investigated. The sampling stations were selected based on their proximity to various human activities in January and February 2022, such as tourism, fishing, urban development and industry. The results showed that the abundance of MP associated with different human activities varied. The highest concentrations were observed near the petrochemical industry in Asaluyeh, followed by the densely populated Bushehr and the fishing port of Dayyer. Other areas such as Ganaveh, Deylam and Mand also showed varying levels of MP contamination. The average MP concentration was 1.67 × 104 particles/km2 in surface water and 1346.67 ± 601.69 particles/kg in dry sediment. Fiber particles were in the majority in both sediment and water samples, mainly black. The sediment samples had a size range of 100-500 μm (41.34 %), while the water samples were between 500 and 1000 μm (33.44 %). The main polymers found were polyethylene (PE) and polypropylene (PP). This assessment highlights the widespread problem of microplastic pollution in the coastal and intertidal zones of Bushehr province in the Persian Gulf.

Microplastic contamination in Thai vinegar crabs (Episesarma mederi), giant mudskippers (Periophthalmodon schlosseri), and their surrounding environment from the Bang Pu mangrove forests, Samut Prakan province, Thailand

The mangrove ecosystem becomes the receptacle for both land- and marine-based plastic waste. This study examines MPs contamination in the Bang Pu mangrove forests (BPMFs) in the inner Gulf of Thailand. For this, Thai vinegar crabs (TVCs) (Episesarma mederi) and giant mudskippers (GMs) (Periophthalmodon schlosseri) were investigated with their surrounding environment in both rainy and dry seasons. Two-step digestion was employed for biota samples. MPs abundance ranged from 7.5 ± 3.8 to 15.9 ± 6.7 items/individual in TVCs and 6.2 ± 5.0 to 10.6 ± 2.6 items/individual in GMs. MPs in small-size ranges (<0.5 mm) were predominant. Fiber MPs were mostly detected in the rainy season. Most MPs were transparent with polyethylene and polypropylene as dominant polymers in all samples. Bioaccumulation was not observed in GMs. The results indicated the imperiled status of MPs contamination in TVCs and GMs with contaminated surrounding environments.

Effect of microplastic particles on the population growth rate and clearance rate of selected ciliates (Protista, Ciliophora)

Microplastics (MPs), due to their micro size, which overlaps with the typical food size of various aquatic organisms, can be ingested and move up the food chain, accumulating in the bodies of organisms at higher trophic levels. Few studies have focused on the uptake of MPs by ciliates, which are an important element of the microbial cycle. Three different ciliate species were used in this study: Blepharisma japonicum, Euplotes sp., and Spirostomum teres, as well as polystyrene beads with diameters of 1 and 2 µm at two concentrations (106 and 107 beads × mL-1). The results of the experiments showed that MPs have a variable, species-specific effect on the population growth rate of ciliates, which is directly dependent on their concentration in the environment (P < 0.01). It was also observed that the number of MPs ingested changed over time depending on their concentration and size. On average, the highest number of ingested MPs (883.11 ± 521.47) was recorded at 60 min of exposure to a low concentration of small beads in B. japonicum. The lowest number of beads was ingested after 5 min of exposure to a low concentration of large beads in the same species. The rate of MP uptake by the ciliate species was significantly dependent on their concentration, exposure time, and size (P < 0.001). The highest clearance rate was observed in the fifth minute of the experiment in the environment with the lowest MP concentration.

Microplastic particles in river sediments and water of southwestern Nigeria: insights on the occurrence, seasonal distribution, composition, and source apportionment

Microplastics (MPs) are globally recognized as an emerging environmental threat, particularly in the aquatic environment. This study presents baseline data on the occurrence and distribution of MPs in sediments and surface water of major rivers in southwestern Nigeria. Microplastics were extracted by density separation and polymer identification using Fourier transformed infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR). The abundance of MPs in surface sediment and water samples across all locations ranged from 12.82 to 22.90 particle/kg dw and 6.71 to 17.12 particle/L during the dry season and 5.69 to 14.38 particle/kg dw and 12.41 to 22.73 particle/L during the wet season, respectively. On average, fiber constituted the highest percentage of MP in sediments (71%) and water (67%) while foam accounted for the lowest values of 0.6% and 1.7%, respectively. Polypropylene (PP) and polyethylene (PE) were the main MPs across all locations based on Fourier transform infrared spectroscopy (FTIR). MPs of size < 1 mm were the most abundant (≥ 55%) on average in both water and sediments. The study identified run-off from human activities and industrial wastewater as potential sources of MP exposure based on positive matrix factorization. The study suggests assessing the impact of different land-use activities on MPs occurrence and distribution in addition to quantifying MPs in seafood as a way forward in food safety management systems for further studies. This study confirmed the occurrence and widespread distribution of MPs in surface water and sediments and provides a database on MP pollution in Nigeria.

Microplastic pollution: Understanding microbial degradation and strategies for pollutant reduction

Microplastics are ubiquitous environmental pollutants with the potential for adverse impacts on ecosystems and human health. These particles originate from the fragmentation of larger plastic items, shedding from synthetic fibers, tire abrasions, and direct release from personal care products and industrial processes. Once released into the environment, microplastics can disrupt ecosystems, accumulate in organisms, cause physical harm, and carry chemical pollutants that pose risks to both wildlife and human health. There is an urgent need to comprehensively explore the multifaceted issue of microplastic pollution and understand microbial degradation to reduce environmental pollution caused by microplastics. This paper presents a comprehensive exploration of microplastics, including their types, composition, advantages, and disadvantages, as well as the journey and evolution of microplastic pollution. The impact of microplastics on the microbiome and microbial communities is elucidated, highlighting the intricate interactions between microplastics and microbial ecosystems. Furthermore, the microbial degradation of microplastics is discussed, including the identification, characterization, and culturing methods of microplastic-degrading microorganisms. Mechanisms of microplastic degradation and the involvement of microbial enzymes are elucidated to shed light on potential biotechnological applications. Strategies for reducing microplastic pollution are presented, encompassing policy recommendations and the importance of enhanced waste management practices. Finally, the paper addresses future challenges and prospects in the field, emphasizing the need for international collaboration, research advancements, and public engagement. Overall, this study underscores the urgent need for concerted efforts to mitigate microplastic pollution and offers valuable insights for researchers, policymakers, and stakeholders involved in environmental preservation.

Effects of near-bed turbulence on microplastics fate and transport in streams

Quantifying the impact of hyporheic exchange is crucial for understanding the transport and fate of microplastics in streams. In this study, we conducted several Computational Fluid Dynamics (CFD) simulations to investigate near-bed turbulence and analyze vertical hyporheic exchange. Different arranged spheres were used to represent rough and permeable sediment beds in natural rivers. The velocities associated with vertical hyporheic flux and the gravitational force were compared to quantify the susceptibility of microplastics to hyporheic exchange. Four scenario cases representing different channel characteristics were studied and their effects on microplastics movements through hyporheic exchange were quantitatively studied. Results show that hyporheic exchange flow can significantly influence the fate and transport of microplastics of small and light-weighted microplastics. Under certain conditions, hyporheic exchange flow can dominate the behavior of microplastics with sizes up to around 800 μm. This dominance is particularly evident near the sediment-water interface, especially at the top layer of sediments. Higher bed porosity enhances the exchange of microplastics between water and sediment, while increased flow conditions extend the vertical exchange zone into deeper layers of the bed. Changes in the bedform lead to the most pronounced vertical hyporheic exchange, emphasizing the control of morphological features on microplastics transport. Furthermore, it is found that sweep-ejection events are prevailing near the bed surface, serving as a mechanism for microplastics transport in rivers. As moving from the water column to deeper layers in the sediment bed, there's a shift from sweeps dominance to ejections dominance, indicating changes of direction in microplastics movement at different locations.

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.

Are fishes selecting the trash they eat? Influence of feeding mode and habitat on microplastic uptake in an artificial reef complex (ARC)

Every year, coastal countries generate ∼275 million tons of plastic, and the oceans receive from 4.8 to 12.7 million tons3. Pollution by synthetic polymers is even more problematic for the environment when this material is fragmented into small portions, forming microplastics (MPs). In the present study, we analyze the selection of MPs by the ichthyofauna based on the availability of the morphotypes and polymeric composition of microplastic in the environment and compare the amount of MP in surface water, water column, sediments and fish in different organs, trophic categories, habitats and areas with and without artificial reefs. In order to achieve this goal, the shape, color, abundance and chemical composition of MPs in the digestive tract and gills of 18 fish species in artificial reefs area and control area, were evaluated. A total of 216 fish were analyzed, and 149 (60 %) had MPs in at least one organ and showed a mean concentration of 1.55 ± 3.31 MPs/g. Of the 18 fish species collected in the reef complex area, 17 (94 %) included individuals with at least one MP in digestive tract or gills. Four species showed the higher selectivity of MP types, colors, and polymers. More MPs were found in the fish, surface water, water column and sediment in the artificial reef area compared to the control areas. This is the first evidence of MP selection by commercially important fish species in artificial marine structures worldwide. These results provide useful information on MP pollution in RAs and highlight yet another issue that must be considered in the management of fisheries resources in the region and in other reef complexes around the world.

Impact of sewing on microfiber release from polyester fabric during laundry

Microfibers released from textile materials are receiving greater attention due to their severe adverse effects on the environment. Although mitigation strategies have been developed for laundering, researchers uphold that it is crucial to start mitigating at the source. In that aspect, this research aims to analyze the cutting and sewing methods of knitted fabrics and their impact on the microfiber release of garments during laundry. The results of the study have confirmed that cutting and sewing methods have a significant impact on the microfiber release of a garment. The analysis of different cutting methods showed that laser and ultrasonic cutting methods reduce the microfiber release up to 20 times compared to the conventional scissor-cut edges. While comparing the different stitch types, the overlock stitch type showed reduced shedding than the other stitch types (flatlock stitch and single needle lockstitch). Our results also showed that the use of more needles increases the microfiber emission among different stitch variations of the same stitch type. For instance, a 45.27 % increase in microfiber emission was reported with the 4-thread overlock stitch (2 needles) than with the 3-thread stitch (1 needle). Regarding seam type, the proposed edge finishing seam (EFb) was effective in reducing 93 % of microfiber release as the edges are completely covered. When the effect of stitch density is considered, in the case of single needle lockstitch and flatlock stitch, the microfiber release is reduced with increased stitch density. However, a different trend was noted in the overlock stitch, which needed detailed exploration in the future. The results confirmed that a proper selection of stitch, stitch density, and seam type would reduce the microfiber release from a garment by up to 64.6 %.

Occurrence of microplastics in three types of household cleaning products and their estimated emissions into the aquatic environment

Microplastics (MPs) in household cleaning products are a significant source of primary MPs. However, their presence in these products remain largely unknown. In this study, three types of common household cleaning products (laundry detergents, toilet bowl cleaners, and dishwashing detergents) were examined to assess the presence of MPs. The potential global emissions of MPs into aquatic environments resulting from the use of these products were estimated using statistics on global wastewater treatment plants (WWTPs) and household cleaning product markets. The average abundance of MPs in household cleaning products was 564.97 ± 327.83 n·kg-1, with toilet bowl cleaners having a significantly higher abundance than the other two products. The most commonly detected polymers in these products were polyamide (PA), silicone, polyurethane (PU), acrylate copolymer (ACR), polyethylene (PE), and polyethylene terephthalate (PET), while the size of the MPs ranged from 21.34 to 442.97 μm, with 81.52 % being <50 μm and 87.32 % being fragment-shaped. The estimated annual MP emissions from these three types of household cleaning products were 3.88 × 1013 ± 1.35 × 1013, with toilet bowl cleaners accounting for 56.44 % of the total emissions. MPs directly released without treatment in WWTPs (2.46 × 1013 n year-1) accounted for 63.40 % of the total emissions, highlighting the importance of increasing the treated rate of wastewater to reduce MP emissions. Sensitivity tests indicated that increasing the MP removal rates of secondary and tertiary WWTPs could also effectively reduce MP emissions. Moreover, gross and per capita MP emissions in 149 countries showed significant differences, which could be attributed to population, market size, demand for household cleaning products, and the level of MP removal among different countries. The findings of this study provide important insights into controlling MP contamination in household cleaning products.

Oxidative stress and histopathological effects by microplastic beads, in the crayfish Procambarus clarkii, and fiddler crab Leptuca pugilator

The present study was aimed at evaluating the in vivo effects of microplastics (MP), in terms of oxidative stress and histopathological effects, in two crustacean species: Procambarus clarkii and Leptuca pugilator. In addition, MP accumulation in the hepatopancreas (HP) of both species was also determined. Adults of both crayfish and crabs were exposed for one month to fluorescent polystyrene beads (size: 1 μm) at nominal concentrations of 1000 or 5000 particles/mL. During the exposure, animals were maintained under controlled feeding, aeration, temperature, and photoperiod conditions. At the end of the exposure, HP and hemolymph (HL) samples were harvested for analysis of oxidative damage and total antioxidant levels. Additionally, the presence of MPs in both tissues was confirmed. Significant differences with the control groups were observed in lipid peroxidation levels in HP in animals exposed to the lowest concentration in P. clarkii and to the highest concentration in L. pugilator. A marked increase in antioxidant levels was also observed in the HL at both concentrations in P. clarkii, and at the highest MPs concentration in L. pugilator. Moreover, several histopathological changes were detected in both gills and HP, including hypertrophied lamellae, lifting or collapse of gill epithelia, loss of normal shape of hepatopancreatic tubules, and epithelial atrophy in the HP tissue. We conclude that exposure to MP beads at selected concentrations results in oxidative damage, induces histopathological changes in gills and HP, and triggers an antioxidant response in two crustacean species.

Exploring Bacillus amyloliquefaciens strain OM81 for the production of polyhydroxyalkanoate (PHA) bioplastic using olive mill wastewater

In this study, bacterial strains isolated from olive oil mill wastewater assigned to Bacillus (n = 4) and Klebsiella (n = 1) genera, were evaluated for their ability to accumulate intracellular PHA granules using Sudan Black staining. A maximum PHA production of 0.14 g/L (i.e., 30.2% wt./wt. in dry biomass) was observed in Bacillus amyloliquefaciens strain OM81 after 72 h of incubation in the presence of 2% glucose (synthetic medium). To reduce bioplastic production costs and recover a polluting product, olive mill wastewater was tested as a carbon source. In this context, the maximum growth (1.45 g/L) was observed in the presence of 50% olive mill wastewater. After extracting the biopolymers with chloroform, quantitative and qualitative analyses were conducted using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). FTIR showed an absorption band at 1730 cm-1 assigned to the elongation of the PHB carbonyl groups. This approach offers a dual benefit of reducing pollution and bioplastic production costs. The Bacillus amyloliquefaciens strain OM81 showed promising results for PHAs production, making it a potential candidate for further investigation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03808-4.

Atmospheric microplastic transport and deposition to urban and pristine tropical locations in Southeast Asia

Atmospheric microplastic transport is an important delivery pathway with the deposition of microplastics to ecologically important regions raising environmental concerns. Investigating atmospheric delivery pathways and their deposition rates in different ecosystems is necessary to understanding its global impact. In this study, atmospheric deposition was collected at three sites in Malaysia, two urban and one pristine, covering the Northeast and Southwest monsoons to quantify the role of this pathway in Southeast Asia. Air mass back trajectories showed long-range atmospheric transport of microplastics to all sites with atmospheric deposition varying from 114 to 689 MP/m2/day. For the east coast of Peninsular Malaysia, monsoonal season influenced microplastic transport and deposition rate with peak microplastic deposition during the Northeast monsoon due to higher wind speed. MP morphology combined with size fractionation and plastic type at the coastal sites indicated a role for long-range marine transport of MPs that subsequently provided a local marine source to the atmosphere at the coastal sites.

Multispectroscopic Investigations of the Binding Interaction between Polyethylene Microplastics and Human Hemoglobin

In this investigation, different multispectroscopic analytical techniques have been used to explore the interaction between polyethylene microplastics (PE-MPs) and human hemoglobin (HHb), an oxygen carrier in the human blood circulatory system. Ultraviolet-visible absorption studies have demonstrated that HHb molecules may interact with PE-MPs, and thermal melting studies have indicated that PE-MPs have a stabilizing effect on HHb. Further circular dichroism and Fourier transform infrared spectroscopic studies have revealed the distinct changes in HHb's secondary structures caused by the formation of the HHb-PE-MP binding complex. These findings imply that PE-MPs could enter the blood circulation system of humans and may be hazardous to humans. This work explains the potential binding interaction of microplastics at the molecular level and offers insight into the intermolecular interaction between PE-MPs and HHb.

The potential of Lecane rotifers in microplastics removal

Dealing with hard-to-degrade plastics pollution of terrestrial and aquatic environments is one of the most urgent problems of the modern world. The smallest fraction (<5 mm) called micro-plastics (MP) has been found everywhere from ice in Greenland, streams, rivers, soil and even in the human placenta. The goal of our research was to assess the ability of rotifers Lecane inermis to remove micro-plastics suspended in the water column. In the experiments we investigated specific interactions between MP, biofilm and rotifers specialized in feeding on biofilm. We hypothesized that MP adhere to the biofilm and after ingestion by rotifers could be extracted from the water in the form of compact conglomerates excreted with fecal pellets. In these experiments, we demonstrated that: (i) the rotifers preferentially ingest microplastics embedded in biofilm, (ii) the presence of microplastics does not affect growth and fecundity of rotifers, and (iii) that MP aggregation is significantly improved by the presence of biofilm, additionally enhanced in the presence of rotifers. Our findings will help to understand the role of micro-grazers, such as L. inermis feeding on biofilm, in the fate of MP in nature. In the longer term, our results could help to develop biotechnological tools for MP removal from the aquatic environment.

Microplastics in coral reef sediments underestimated? They may hide in biominerals

Microplastics (MPs) may be underestimated in coral reef sediments. Current pretreatments for determining MPs in the sediments are mainly density separation and organic matter removal, ignoring MPs that may be embedded or encrusted in biominerals. This could lead to discrepancies in assessing the potential risk of MPs contamination. To confirm whether MPs in coral reef sediments are underestimated, a two-step sequential digestion, including organic matter removal (H2O2 digestion) and biomineral removal (HCl digestion), was performed on sediments from the coral reef area of the South Penghu Marine National Park (SPMNP, Taiwan). The MPs abundance and characteristics of the two steps were analyzed separately. The results showed that the average MPs abundance after HCl digestion (78 ± 42 MPs/kg) was significantly higher than that of H2O2 digestion (38 ± 25 MPs/kg). The MPs diversity integrated index (MPDII) in coral reef sediments was low (MPDII = 0.35), and MPs were mainly small (<2.0 mm, 91.3 %), fibrous (93.5 %), colored (60.9 %), and rayon polymers (73.9 %). Correlation analysis showed that MPs in biominerals mainly dominated MPs in the sediments. These results confirm that current assessments of MPs contamination levels in biomineral-rich sediments may be underestimated and uncertain. In addition, the mineralization of organisms in SPMNP reef regions was affected by MPs from moderate to high levels, depending on the proportion of MPs in biominerals.

Ecotoxicity of micro- and nanoplastics on aquatic algae: Facts, challenges, and future opportunities

The production of plastic has exponentially increased in recent years, leading to the release of millions of tons of plastic waste into the environment annually. This waste can break down into smaller micro- and nanoplastics (MNPs) that are toxic and reactive to life forms, including humans. MNPs are particularly concerning for marine biologists and environmental scientists due to their toxic impacts on aquatic organisms, including algae, which are the foundation of the food chain. The review provides a comprehensive overview of the (eco)toxicity assessment of MNPs on aquatic algal communities, highlighting the novel insights gained into the ecotoxicity of various MNPs on algae and the associated health risks for aquatic ecosystems, food chains, and humans. This article also discusses current challenges and future research opportunities to address these challenges, making it a valuable contribution to the field of environmental science. Overall, this work is one of the first efforts to comprehensively assess the effects of MNPs on aquatic algae, emphasizing the significant risks that MNPs pose to essential ecosystems and human health.

Interaction of fluorene and its analogs with high-density polyethylene microplastics: An assessment of the adsorption mechanism to establish the effects of heteroatoms in the molecule

The threat of microplastics (MP) pollution in aquatic ecosystems can be even more severe for they are able to interact with organic pollutants that can migrate to adjacent environments. The presence of heteroatoms in organic pollutants can directly influence adsorption onto MP. This research evaluated the adsorption of fluorene (FLN) and its heteroatom analogs dibenzothiophene (DBT), dibenzofuran (DBF) and carbazole (CBZ) onto high-density polyethylene (HDPE) MP from residual (HDPEres) and commercial (HDPEcom) sources. The Langmuir isotherm showed a better fit, while DBT showed higher maximum adsorption capacity (19.2 and 15.8 μmol g-1) followed by FLN (13.4 and 11.7 μmol g-1), and DBF (13.5 and 10.3 μmol g-1) to the HDPEcom and HDPEres, respectively, which indicates a direct correlation with the hydrophobicity of the molecules determined by Log Kow. In contrast, CBZ showed no significant interaction with MP, due to their polar characteristic, thus, no kinetic and thermodynamic parameters could be determined. The adsorption process of all PAH was determined to be exothermic and spontaneous, with low temperatures favoring the process. The pseudo-second-order kinetic models have fitted to the adsorption onto both HDPE; intraparticle diffusion was also observed. Computational studies, physical characterization techniques and batch adsorption experiments demonstrated that the mechanism is governed by hydrophobic interactions, with van der Waals forces as a secondary effect in the adsorption of FLN, DBT and DBF onto HDPEres and HDPEcom. Thus, allowing a deeper understanding of the interactions between HDPE MP and FLN as well with its derivatives.

A review of microalgae biofilm as an eco-friendly approach to bioplastics, promoting environmental sustainability

In this comprehensive review, we delve into the challenges hindering the large-scale production of microalgae-based bioplastics, primarily focusing on economic feasibility and bioplastic quality. To address these issues, we explore the potential of microalgae biofilm cultivation as a sustainable and highly viable approach for bioplastic production. We present a proposed method for producing bioplastics using microalgae biofilm and evaluate its environmental impact using various tools such as life cycle analysis (LCA), ecological footprint analysis, resource flow analysis, and resource accounting. While pilot-scale and large-scale LCA data are limited, we utilize alternative indicators such as energy efficiency, carbon footprint, materials management, and community acceptance to predict the environmental implications of commercializing microalgae biofilm-based bioplastics. The findings of this study indicate that utilizing microalgae biofilm for bioplastic production offers significant environmental sustainability benefits. The system exhibits low energy requirements and a minimal carbon footprint. Moreover, it has the potential to address the issue of wastewater by utilizing it as a carbon source, thereby mitigating associated problems. However, it is important to acknowledge certain limitations associated with the method proposed in this review. Further research is needed to explore and engineer precise techniques for manipulating microalgae biofilm structure to optimize the accumulation of desired metabolites. This could involve employing chemical triggers, metabolic engineering, and genetic engineering to achieve the intended goals. In conclusion, this review highlights the potential of microalgae biofilm as a viable and sustainable solution for bioplastic production. While acknowledging the advantages, it also emphasizes the need for continued synthetic studies to enhance the efficiency and reliability of this approach. By addressing the identified drawbacks and maximizing the utilization of advanced techniques, we can further harness the potential of microalgae biofilm in contributing to a more environmentally friendly and economically feasible bioplastic industry.

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.

Exploring the impact of PVC and PVA microplastics on zebrafish tissue using multi-spectral imaging, Optical Coherence Tomography (OCT) and biospeckle OCT (bOCT)

Plastics are widely used in industry and households, but improper disposal has caused their accumulation in aquatic systems worldwide. As a result, mechanical and photochemical processes break down these plastics into microplastics or nano plastics, posing a severe threat to marine organisms and humans as they enter the food chain. This study investigates the effect of Polyvinyl chloride (PVC) and Polyvinyl alcohol (PVA) microplastics in zebrafish by using multi-spectral imaging (MSI), Optical Coherence Tomography (OCT), and Biospeckle OCT (bOCT). These techniques allow for long-term studies in the fish without invasive procedures in real-time. Zebrafish were exposed to Nile red labeled PVC and PVA for 21 days with 500mg/L concentration. Image acquisition and analysis were performed every five days till the end of the study. MSI images revealed deposition of microplastics in the gills region of the fish; some diffused deposition was seen throughout the body in the PVA group towards the end of the experiment. The effect of these MPs on the structure of the gills and their exact location was determined by capturing OCT images. bOCT was used to determine the average speckle contrast for all the OCT images to determine the change in biological activity within the gills region. An increase in bioscpeckle contrast was observed for the MPs treated groups compared to the control group. PVC appeared to cause a more considerable rise in activity compared to PVA. The results indicated that the MPs exert stress on the gills and increase activity within the gills, possibly due to the blockage of the gills and disruption of the water filtration process, which could be monitored non-invasively only by using bOCT. Overall, our study demonstrates the usefulness of non-invasive, robust techniques like MSI, bOCT, and biospeckle for long-term zebrafish studies and real-time analyses.

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

The increase of microplastic contamination in Vietnam is a growing concern due to various domestic, agricultural, and industrial activities. The use of plastic mulch and sludge application in agricultural farmland, textile production, daily consumer items, cleaning agents, and health/personal care products contribute significantly to the increasing microplastic pollution in the aquatic ecosystem. The concentration of microplastics reported in surface water ranged from 0.35 to 519,000 items m-3, with fibers and fragments being the most prevalent shapes. Notably, the high concentration of microplastics was observed in lakes, canals, and megacities such as Ha Noi and Ho Chi Minh City, which poses potential health risks to the local community via drinking-water supply and food chains. As an emerging pollutant, MPs are the transport vectors for contaminants in environmental matrices that act as a carrier of hazardous pollutants, release toxic compounds, and evenly aggregate/accumulate in biota. Recent studies have reported the presence of microplastics in various marine organisms, including fish and shellfish, highlighting the risk of ingestion of these particles by humans and wildlife. Thus, it is imperative to monitor microplastic contamination in the ecosystem to provide helpful information for the government and local communities. Efforts should be taken to reduce microplastic pollution at the source to minimize potential effects on ecological and health safety. This review paper emphasizes the urgent need for further research on microplastic pollution in Vietnam and highlights potential solutions to mitigate this emerging environmental threat. KEYWORKS: single-use plastics; microplastics; ecosystems; plastic waste; health risk; ecological and health safety; pollution mitigation.

Fenton and photo-assisted advanced oxidative degradation of ionic liquids: a review

Ionic liquids (ILs) are the class of materials which are purely ionic in nature and liquid at room temperature. Their remarkable properties like very low vapour pressure, non-inflammable and high heat resistance are responsible for their use as a very appealing solvent in a variety of industrial applications in place of regular organic solvents. Because ILs are water soluble to a certain extent, the industrial wastewater effluents are found to contaminate with their traces. The non-biodegradability of ILs attracts the attention of the researchers for their removal or degradation from wastewater. Numbers of methods are available for the treatment of wastewater. However, it is very crucial to use the most efficient method for the degradation of ILs. Advanced oxidation process (AOP) is one of the most important techniques for the treatment of ILs in wastewater which have been investigated during last decades. This review paper covers the cost-effective Fenton, photochemical and photocatalytic AOPs and their combination that could be applied for the degradation of ILs from the wastewater. Theoretical explanations of these AOPs along with experimental conditions and kinetics of degradation or removal of ILs from water and wastewater have been reported and compared. Finally, future perspectives of IL degradation are presented.

Current studies on the degradation of microplastics in the terrestrial and aquatic ecosystem

Soil and water are two important basic ecosystems for the survival of different organisms. The excessive microplastic pollutants in soil have been directly discharged into the terrestrial ecosystems. Microplastic pollutants (MPs) constitute a ubiquitous global menace due to their durability, flexibility, and tough nature. MPs posed threat to the sustainability of the ecosystem due to their small size and easy transportation via ecological series resulting in the accumulation of MPs in aquatic and terrestrial ecosystems. After being emitted into the terrestrial ecosystem, the MPs might be aged by oxidative degeneration (photo/thermal), reprecipitation (bioturbation), and hetero-accumulation. The mechanism of adsorption, degradation, and breakdown of MPs into unaffected plastic debris is accomplished by using several biological, physical, and chemical strategies. This review presents the importance of ecosystems, occurrence and sources of MPs, its toxicity, and the alteration in the ecology of the ecosystems. The inhibitory impact of MPs on the ecosystems also documents to unveil the ecological hazards of MPs. Further research is required to study the immobilization and recovery efficiency of MPs on a larger scale.

Polyethylene degradation and heavy metals leaching under realistic tropical marine climate

The study examines the influence of temperature and pH on the leaching of six heavy metals (HMs) species: aluminum (Al), zinc (Zn), chromium (Cr), copper (Cu), lead (Pb) and arsenic (As) from transparent polyethylene pellets into seawater. The idea is to understand the potential influence of intensifying global warming and ocean acidification towards microplastic toxicity in the ocean. HMs leaching was obvious by 24th hours, with most HMs concentration decreased in water by 120th and 240th hours except Al. Nevertheless, we report that temperature and pH do not influence the overall HMs leaching from PE pellets with statistical analysis showing no significance (p < 0.05) between temperature and pH toward HMs concentration. Instead, it is hypothesized that these two parameters may be crucial in promoting heavy metal adsorption onto PE pellets under tropical weathering. However, Field Emission Scanning Electron Microscope (FESEM) revealed that temperature and pH are influential in polymer aging and surficial breakdown where pellets exposed in warm, acidic waters showed the greatest extent of weathering. This study highlights that PE pellets exposed under tropical conditions may accelerate surficial degradation and possibly stimulate HMs adherence to the polymer as a pollution vector. Further consideration of metal behaviour in water and microbial activities is crucial to improve our understanding of microplastic toxicity under tropical weathering.

Impact of microplastics on riverine greenhouse gas emissions: a view point

In recent decades, microplastics (MPs < 5 mm) are ubiquitous and considered a serious emerging environmental problem. However, due to the limited recovery and long-lasting durability MPs, debris is frequently accumulating in riverine ecosystems, thereby impacting microbial activity and its communities. The presence of MPs may alter the microbial richness, variety, and population, thereby impacting the transformation of biogeochemical cycles. The occurrence, fate, and transport of MPs in marine and terrestrial ecosystems and their impact on biogeochemical or nutrient cycling are reported in the scientific fraternity. Yet, the global scientific community is conspicuously devoid of research on impact of MPs on riverine greenhouse gas (GHG) emissions. The presented view point provides a novel idea about the fate of MPs in the riverine system and its impact on GHG emissions potential. Literature reveals that DO and nutrients (organic carbon, NH4+, NO3-) concentrations play an important role in potential of GHG emission in riverine ecosystems. The proposed mechanism and research gaps provided will be highly helpful to the hydrologist, environmentalist, biotechnologist, and policymakers to think about the strategic mitigation measure to resolve the future climatic risk.

Ecological traits do not predict the uptake of microplastics by fishes in a Neotropical River

Pollution by synthetic polymers is even more problematic to the environment when this material is fragmented into small portions, forming microplastics (MPs). We analyzed the contamination of ichthyofauna by MPs in an important river of the Atlantic Rainforest in regard to abundance, diversity of morphotypes, polymers, colors, and sizes of the synthetic particles in 20 species of fish. Fish were collected in November 2019 and in March 2020 in five sites along the Pomba River. Of the 101 fish analyzed, 49 (49%) presented MPs in at least one organ. Of the 20 species of fish collected 13 included individuals with at least one MP in their analyzed organs. The organs, trophic categories and feeding areas did not affect the general abundance of MPs types. Blue MPs were predominant, followed by the colors black, red, and white. MP fibers represented 91% of total MPs. Most MPs were between 2 and 3 mm in size. Polyethylene terephthalate (PET), polypropylene (PP), polyamide (PA), polyvinylidene chloride "Nylon" (PVDC), and high-density polyethylene (HDPE) were detected in the fishes. The exposure of the fish species to MPs was associated mainly with individual size and species-specific aspects, regardless of ecological traits. Considering that 55% of the fish species studied are consumed by humans, it is necessary to study the potential impact of MP ingestion on human health and to understand to what extent we may be consuming both plastic particles and contaminants that are adsorbed to MPs.

Modelling marine microplastics accumulation zones through freshwater discharge sources: Simulated release from the Onkaparinga River and Torrens River, South Australia

Plastic pollution is fast becoming one of the most prominent contamination issues facing the marine environment. Microplastics are a major subset of plastic waste now present in all global oceans, with their numbers standing only to increase. This study applies a coupled hydrodynamic model and Lagrangian particle-tracking model to predict and simulate microplastic transport in South Australian waters. Virtual particles representing microplastics were released daily for 365 days from two major freshwater input sources along the coastline of Adelaide, Australia. These particles entered the Gulf St Vincent and were tracked over two model years using LTRANS software. The model identified general gulf circulation as circular, clockwise, with net southward particle transport from particle release sites. A potential accumulation zone associated with a local eddy was identified. Concentrations of particles that passed through local marine parks were also calculated in response to the potential concerns they pose in vulnerable protected areas.