Interactions of microplastics and organic compounds in aquatic environments: A case study of augmented joint toxicity

Microplastics and Oxidative Stress-Current Problems and Prospects

Microplastics (MPs) are plastic particles between 0.1 and 5000 µm in size that have attracted considerable attention from the scientific community and the general public, as they threaten the environment. Microplastics contribute to various harmful effects, including lipid peroxidation, DNA damage, activation of mitogen-activated protein kinase pathways, cell membrane breakages, mitochondrial dysfunction, lysosomal defects, inflammation, and apoptosis. They affect cells, tissues, organs, and overall health, potentially contributing to conditions like cancer and cardiovascular disease. They pose a significant danger due to their widespread occurrence in food. In recent years, information has emerged indicating that MPs can cause oxidative stress (OS), a known factor in accelerating the aging of organisms. This comprehensive evaluation exposed notable variability in the reported connection between MPs and OS. This work aims to provide a critical review of whether the harmfulness of plastic particles that constitute environmental contaminants may result from OS through a comprehensive analysis of recent research and existing scientific literature, as well as an assessment of the characteristics of MPs causing OS. Additionally, the article covers the analytical methodology used in this field. The conclusions of this review point to the necessity for further research into the effects of MPs on OS.

Global producer responsibility for plastic pollution

Brand names can be used to hold plastic companies accountable for their items found polluting the environment. We used data from a 5-year (2018-2022) worldwide (84 countries) program to identify brands found on plastic items in the environment through 1576 audit events. We found that 50% of items were unbranded, calling for mandated producer reporting. The top five brands globally were The Coca-Cola Company (11%), PepsiCo (5%), Nestlé (3%), Danone (3%), and Altria (2%), accounting for 24% of the total branded count, and 56 companies accounted for more than 50%. There was a clear and strong log-log linear relationship production (%) = pollution (%) between companies' annual production of plastic and their branded plastic pollution, with food and beverage companies being disproportionately large polluters. Phasing out single-use and short-lived plastic products by the largest polluters would greatly reduce global plastic pollution.

Freshwater plastisphere: a review on biodiversity, risks, and biodegradation potential with implications for the aquatic ecosystem health

The plastisphere, a unique microbial biofilm community colonizing plastic debris and microplastics (MPs) in aquatic environments, has attracted increasing attention owing to its ecological and public health implications. This review consolidates current state of knowledge on freshwater plastisphere, focussing on its biodiversity, community assembly, and interactions with environmental factors. Current biomolecular approaches revealed a variety of prokaryotic and eukaryotic taxa associated with plastic surfaces. Despite their ecological importance, the presence of potentially pathogenic bacteria and mobile genetic elements (i.e., antibiotic resistance genes) raises concerns for ecosystem and human health. However, the extent of these risks and their implications remain unclear. Advanced sequencing technologies are promising for elucidating the functions of plastisphere, particularly in plastic biodegradation processes. Overall, this review emphasizes the need for comprehensive studies to understand plastisphere dynamics in freshwater and to support effective management strategies to mitigate the impact of plastic pollution on freshwater resources.

Tire additives: Evaluation of joint toxicity, design of new derivatives and mechanism analysis of free radical oxidation

N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) is one of the most widely used antioxidant agents in tire additives. Its ozonation by-product 6PPD-quinone has recently been recognized as inducing acute mortality in aquatic organisms such as coho salmon. In this study, we aimed to develop an in-silico method to design environmentally friendly 6PPD derivatives and evaluate the joint toxicity of 6PPD with other commonly used tire additives on coho salmon through full factorial design-molecular docking and molecular dynamic simulation. The toxicity mentioned in this study is represented by the binding energy of chemical(s) binding to the coho salmon growth hormone. The recommended formula for tire additives with relatively low toxicity was then proposed. To further reduce the toxicity of 6PPD, 129 6PPD derivatives were designed based on the N-H bond dissociation reaction, and three of these derivatives showed improved antioxidant activity and 6PPD-106 was finally screened as the optimum alternative with lower toxicity to coho salmon. Besides, the mechanism of free radical oxidation (i.e., antioxidation and ozonation metabolic pathway) for 6PPD-106 was also analyzed and found that after ozonation, the toxicity of 6PPD-106's by-products is much lower than that of 6PPD's by-products. This study provided a molecular modelling-based examination of 6PPD, which comprehensively advanced the understanding of 6PPD's environmental behaviors and provided more environmentally friendly 6PPD alternatives with desired functional property and lower ecological risks.

An Atomic-Level Perspective on the interactions between Organic Pollutants and PET particles: A Comprehensive Computational Investigation

Microplastics (MPs) have recently attracted a lot of attention worldwide due to their abundance and potentially harmful effects on the environment and on human health. One of the factors of concern is their ability to adsorb and disperse other harmful organic pollutants in the environment. To properly assess the adsorption capacity of MP for organic pollutants in different environments, it is pivotal to understand the mechanisms of their interactions in detail at the atomic level. In this work, we studied interactions between polyethylene terephthalate (PET) MP and small organic pollutants containing different functional groups within the framework of density functional theory (DFT). Our computational outcomes show that organic pollutants mainly bind to the surface of a PET model via weak non-bonding interactions, mostly hydrogen bonds. The binding strength between pollutant molecules and PET particles strongly depends on the adsorption site while we have found that the particle size is of lesser importance. Specifically, carboxylic sites are able to form strong hydrogen bonds with pollutants containing hydrogen bond donor or acceptor groups. On the other hand, it is found that in such kind of systems π-π interactions play a minor role in adsorption on PET particles.

Oxidative stress and energy metabolic response of Isochrysis galbana induced by different types of pristine and aging microplastics and their leachates

The aging process and leachate composition of different types of MPs (PS, PS-NH2, PS-COOH and PMMA) with a particle size of 1.0 μm were characterized, and marine microalgae Isochrysis galbana OA3011(I. galbana) was used as test organism to investigate the 96 h toxic effects of MPs before and after aging as well as leachate exposure. Except for polymethyl methacrylate (PMMA), all other tested microplastics showed significant aggregation in seawater, which increased with the presence of surface amino and carboxyl groups, in addition, the increase in polymer dispersibility index (PDI) values after aging reflected more severe aggregation. Fourier transform infrared spectrometer (FTIR) showed that the surface amino groups were shed during the aging of PS-NH2, which can likewise be demonstrated by the change in surface electric potential from positive to negative before and after aging. PMMA, due to the addition of plasticizers (HEHP and DIBP detected in high concentration) and its own structure, has stronger resistance to aging than the other three microplastics, and no significant aging phenomenon occurs. As for I. galbana, growth inhibition, oxidative stress and energy metabolism were tested after exposure to different microplastics and their leachate. It was found that high concentrations of A-PS had a greater negative impact on I. galbana, while the toxic effects of PS-NH2 and PS-COOH on I. galbana behaved in a diametrically opposite way before and after aging compared to PS with the inhibitory effect decreasing after aging, which was caused by the shedding of surface groups. As for PMMA, the differences in the toxic effects on microalgae before and after aging were not significant. The inhibitory effect of low concentrations of PAEs (Phthalate acid esters) in the leachate of PS-COOH on I. galbana was not significant, and the stronger inhibitory effect of 4 d L-PS-NH2 was presumed to be the shedding of positively charged groups.

Methamphetamine Shows Different Joint Toxicity for Different Types of Microplastics on Zebrafish Larvae by Mediating Oxidative Stress

The coexistence of polystyrene (PS) and polypropylene (PVC) microplastics (MPs) and methamphetamine (METH) in aquatic systems is evident. However, the joint toxicity is unclear. Here, zebrafish larvae were exposed to single PS and PVC MPs (20 mg L-1) and combined with METH (250 and 500 μg L-1) for 10 days. The results indicated that acute exposure to PS and PVC MPs induced lethal effects on zebrafish larvae (10-20%). Treatment with MPs markedly suppressed the locomotion of zebrafish, showing as the lengthy immobility (51-74%) and lower velocity (0.09-0.55 cm s-1) compared with the control (1.07 cm s-1). Meanwhile, histopathological analysis revealed pronounced depositions of MPs particles in fish's intestinal tract, triggering inflammatory responses (histological scores: 1.6-2.0). In the coexposure groups, obviously inflammatory responses were found. Furthermore, the up-regulations of the genes involved in the oxidative kinase gene and inflammation related genes implied that oxidative stress triggered by MPs on zebrafish larvae might be responsible for the mortality and locomotion retardant. The antagonistic and stimulatory effects of METH on the expression changes of genes found in PVC and PS groups implied the contrary combined toxicity of PS/PVC MPs and METH. This study for the first time estimated the different toxicity of PS and PVC MPs on fish and the joint effects with METH at high environmental levels. The results suggested PS showed stronger toxicity than PVC for fish larvae. The addition of METH stimulated the effects of PS but antagonized the effects of PVC, promoting control strategy development on MPs and METH in aquatic environments.

The enhancement in toxic potency of oxidized functionalized polyethylene-microplastics in mice gut and Caco-2 cells

Microplastics (MPs) are inevitably oxidized in the environment, however, to date, no studies have discussed the biological toxicity of oxidized polyethylene (Ox-PE) MPs. In this study, oxidized low-density polyethylene (Ox-LDPE), a representative Ox-PE, was prepared using a selective oxidation method. The difference in toxicity between LDPE-MPs and Ox-LDPE-MPs were evaluated in C57BL/6 mice and Caco-2 cells. The proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopy analyses revealed that some hydrocarbon-containing groups were transformed into carboxyl and ketone groups during selective oxidation. In vivo experiment results showed that LDPE-MPs and Ox-LDPE-MPs exists in the intestinal (duodenum and colon) of mice, and Ox-LDPE-MPs caused more severe intestinal histological changes, oxidative stress, and inflammatory response. The gut microbiota data showed that the relative abundance of Lactobacillus decreased significantly in the LDPE-MP- and Ox-LDPE-MP-exposed groups (P < 0.05). The predicted Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway suggested that exposure to LDPE-MPs or Ox-LDPE-MPs inhibited glycan biosynthesis and metabolism in the flora (P < 0.05). In vitro experiment results showed that selective oxidation to LDPE promoted its uptake by cells and aggravated adverse effects on cells, including reduced cell viability, damaged cell membrane, oxidative stress, and mitochondrial depolarization. The major mechanism of the increased toxicity of Ox-LDPE-MPs may be its easier accumulation and the ionic effect of oxygen-containing functional groups. Overall, these findings provide insights on the differences in toxicity between LDPE-MPs and Ox-LDPE-MPs. They also provide new perspectives for understanding the biohazards of MPs, which are necessary to accurately assess the potential environmental and health risks of these plastic pollutants.

Microbial colonization patterns and biodegradation of petrochemical and biodegradable plastics in lake waters: insights from a field experiment

Introduction

Once dispersed in water, plastic materials become promptly colonized by biofilm-forming microorganisms, commonly known as plastisphere.

Methods

By combining DNA sequencing and Confocal Laser Scanning Microscopy (CLSM), we investigated the plastisphere colonization patterns following exposure to natural lake waters (up to 77 days) of either petrochemical or biodegradable plastic materials (low density polyethylene - LDPE, polyethylene terephthalate - PET, polylactic acid - PLA, and the starch-based MaterBi® - Mb) in comparison to planktonic community composition. Chemical composition, water wettability, and morphology of plastic surfaces were evaluated, through Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), and static contact angle analysis, to assess the possible effects of microbial colonization and biodegradation activity.

Results and Discussion

The phylogenetic composition of plastisphere and planktonic communities was notably different. Pioneering microbial colonisers, likely selected from lake waters, were found associated with all plastic materials, along with a core of more than 30 abundant bacterial families associated with all polymers. The different plastic materials, either derived from petrochemical hydrocarbons (i.e., LDPE and PET) or biodegradable (PLA and Mb), were used by opportunistic aquatic microorganisms as adhesion surfaces rather than carbon sources. The Mb-associated microorganisms (i.e. mostly members of the family Burkholderiaceae) were likely able to degrade the starch residues on the polymer surfaces, although the Mb matrix maintained its original chemical structure and morphology. Overall, our findings provide insights into the complex interactions between aquatic microorganisms and plastic materials found in lake waters, highlighting the importance of understanding the plastisphere dynamics to better manage the fate of plastic debris in the environment.

Risk assessment framework for microplastic in marine environments

Constantly raising microplastic (MP) contamination of water sources poses a direct threat to the gentle balance of the marine environment. This study focuses on a multifactor hazard evaluation of conventional (polyethylene - PE, polypropylene - PP, and polystyrene - PS) and alternative (polyethylene terephthalate with 25 % or 50 % recycled material and polylactic acid) plastics. The risk assessment framework explored included MP abundance, water acidification potential, surface oxidation, fragmentation, and bacterial growth inhibition. Based on MP monitoring campaigns worldwide, we conclude that PE-based plastics are the most abundant MPs in water samples (comprise up to 82 % the MP in those samples). A year-long weathering experiment showed that PS-based and PP-based plastics were oxidized to a higher extent, resulting in the highest water acidification with pH reduction of up to three orders of magnitude. Finally, our laboratory experiments showed that weathered PS was the most fragile plastic during mechanical degradation, while both PP- and PS-based plastic extracts showed a significant growth inhibition toward the marine microorganisms (Bacillus sp. and Pseudoaltermonas sp). Using the examined factors as weighted inputs into our framework, this holistic evaluation of hazards suggest that PP-based plastic products were the most hazardous compared to the other conventional and alternative plastic types.

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.

The bioaccessibility of adsorped heavy metals on biofilm-coated microplastics and their implication for the progression of neurodegenerative diseases

Microplastic (MP) tiny fragments (< 5 mm) of conventional and specialized industrial polymers are persistent and ubiquitous in both aquatic and terrestrial ecosystem. Breathing, ingestion, consumption of food stuffs, potable water, and skin are possible routes of MP exposure that pose potential human health risk. Various microorganisms including bacteria, cyanobacteria, and microalgae rapidly colonized on MP surfaces which initiate biofilm formation. It gradually changed the MP surface chemistry and polymer properties that attract environmental metals. Physicochemical and environmental parameters like polymer type, dissolved organic matter (DOM), pH, salinity, ion concentrations, and microbial community compositions regulate metal adsorption on MP biofilm surface. A set of highly conserved proteins tightly regulates metal uptake, subcellular distribution, storage, and transport to maintain cellular homeostasis. Exposure of metal-MP biofilm can disrupt that cellular homeostasis to induce toxicities. Imbalances in metal concentrations therefore led to neuronal network dysfunction, ROS, mitochondrial damage in diseases like Alzheimer's disease (AD), Parkinson's disease (PD), and Prion disorder. This review focuses on the biofilm development on MP surfaces, factors controlling the growth of MP biofilm which triggered metal accumulation to induce neurotoxicological consequences in human body and stategies to reestablish the homeostasis. Thus, the present study gives a new approach on the health risks of heavy metals associated with MP biofilm in which biofilms trigger metal accumulation and MPs serve as a vector for those accumulated metals causing metal dysbiosis in human body.

In situ imaging of the spatial and temporal penetration of organic pollutants into microplastics via surface-enhanced Raman spectroscopy

Understanding the spatial and temporal penetration patterns of organic pollutants in microplastics (μP) is important for evaluating their environmental and biological impacts, such as the "Trojan Horse" effect. However, there is a lack of an effective method to monitor the penetration processes and patterns in situ. This study aimed to develop a simple and sensitive approach for in situ imaging of organic pollutant penetration into μP. The novel method was developed using surface-enhanced Raman spectroscopy (SERS) coupled with gold nanoparticles as nanoprobes that could sensitively detect organic pollutants in low-density polyethylene (LDPE) μP spatially and temporally. The detection limit of this SERS-based method was 0.36 and 0.02 ng/mm² for ferbam (pesticide) and methylene blue (synthetic dye), respectively. The results showed that both ferbam and methylene blue could penetrate LDPE μP. The penetration depth and amount increased as the interaction time increased. Most of the absorbed organic pollutants accumulated within the top 90 μm layer of the tested μP. Compared to methylene blue, ferbam was more quickly absorbed and achieved higher accumulation in μP with a maximum of 32.57 ng/mm² after 168 h interaction. This pioneering study clearly demonstrated that SERS mapping is a sensitive and in situ approach to visualize and quantify the penetration patterns of organic pollutants in μP. The new approach developed here can advance our understanding of μP as pollutant carriers and their influence on the environmental fate, behavior, and biological impacts of organic pollutants.

Adsorption behavior of triclosan on microplastics and their combined acute toxicity to D. magna

Microplastics (MP) have been recently identified as emerging water contaminants in worldwide. Owing to its physicochemical properties, MP have been considered as a vector of other micropollutants and may affect their fate and ecological toxicity in the water environment. In this study, triclosan (TCS), which is a widely-used bactericide, and three frequently found types of MP (PS-MP, PE-MP, and PP-MP) were investigated. The adsorption behavior of TCS on MP was investigated by the effect of reaction time, initial concentration of TCS, and other water chemistry factors. Elovich model and Temkin model are the most fitted well with kinetics and adsorption isotherms, respectively. The maximum TCS adsorption capacities were calculated for PS-MP (9.36 mg/g), PP-MP (8.23 mg/g), and PE-MP (6.47 mg/g). PS-MP had higher affinity to TCS owing to hydrophobic and π-π interaction. The TCS adsorption on PS-MP was inhibited by decreasing concentrations of cations, and increasing concentration of anion, pH, and NOM concentration. At pH 10, only 0.22 mg/g of adsorption capacity was obtained because of the isoelectric point (3.75) of PS-MP and pKa (7.9) of TCS. And almost no TCS adsorption occurred at NOM concentration of 11.8 mg/L. Only PS-MP had no acute toxic effect on D. magna, whereas TCS showed acute toxicity (EC_50,24h of TCS = 0.36 ± 0.4 mg/L). Although survival rate increased when TCS with PS-MP due to lower the TCS concentration in solution via adsorption, PS-MP was observed in intestine and body surface of D. magna. Our findings can contribute to understanding the combined potential effects of MP fragment and TCS to aquatic biota.

There's something in the air: A review of sources, prevalence and behaviour of microplastics in the atmosphere

Literature regarding microplastics in the atmosphere has advanced in recent years. However, studies have been undertaken in isolation with minimal collaboration and exploration of the relationships between air, deposition and dust. This review collates concentrations (particle count and mass-based), shape, size and polymetric characteristics for microplastics in ambient air (m3), deposition (m2/day), dust (microplastics/g) and snow (microplastics/L) from 124 peer-reviewed articles to provide a holistic overview and analysis of our current knowledge. In summary, ambient air featured concentrations between <1 to >1000 microplastics/m³ (outdoor) and <1 microplastic/m³ to 1583 ± 1181 (mean) microplastics/m³ (indoor), consisting of polyethylene terephthalate, polyethylene, polypropylene. No difference (p > 0.05) was observed between indoor and outdoor concentrations or the minimum size of microplastics (p > 0.5). Maximum microplastic sizes were larger indoors (p < 0.05). Deposition concentrations ranged between 0.5 and 1357 microplastics/m²/day (outdoor) and 475 to 19,600 microplastics/m²/day (indoor), including polyethylene, polystyrene, polypropylene, polyethylene terephthalate. Concentrations varied between indoor and outdoor deposition (p < 0.05), being more abundant indoors, potentially closer to sources/sinks. No difference was observed between the minimum or maximum reported microplastic sizes within indoor and outdoor deposition (p > 0.05). Road dust concentrations varied between 2 ± 2 and 477 microplastics/g (mean), consisting of polyvinyl chloride, polyethylene, polypropylene. Mean outdoor dust concentrations ranged from <1 microplastic/g (remote desert) to between 18 and 225 microplastics/g, comprised of polyethylene terephthalate, polyamide, polypropylene. Snow concentrations varied between 0.1 and 30,000 microplastics/L, containing polyethylene, polyamide, polypropylene. Concentrations within indoor dust varied between 10 and 67,000 microplastics/g, including polyethylene terephthalate, polyethylene, polypropylene. No difference was observed between indoor and outdoor concentrations (microplastics/g) or maximum size (p > 0.05). The minimum size of microplastics were smaller within outdoor dust (p > 0.05). Although comparability is hindered by differing sampling methods, analytical techniques, polymers investigated, spectral libraries and inconsistent terminology, this review provides a synopsis of knowledge to date regarding atmospheric microplastics.

Interaction between microplastics and humic acid and its effect on their properties as revealed by molecular dynamics simulations

The characteristics and fates of microplastics (MPs) and humic acid (HA) in the environment are significantly influenced by their interactions. Thus, the influence of the MP-HA interaction on their dynamic characteristics was explored. Upon MP-HA interaction, the number of hydrogen bonds established in the HA domains decreased significantly, and the water molecules bridging the hydrogen bonds shifted to the exterior regions of the MP-HA aggregates. The distribution intensity of Ca²⁺ located at ∼0.21 nm around HA deceased, indicating that the coordination of Ca²⁺ with the carboxyl on HA was impaired in the presence of MPs. Additionally, the Ca²⁺-HA electrostatic interaction was suppressed because of the steric hindrance of the MPs. However, the MP-HA interaction improved the distribution of water molecules and metal cations around the MPs. The diffusion coefficient of HA decreased from 0.34 × 10^-5 cm²/s to 0.20-0.28 × 10^-5 cm²/s in the presence of MPs, implying that the diffusion of HA was retarded. The diffusion coefficients of polyethylene and polystyrene increased from 0.29 × 10^-5 cm²/s and 0.18 × 10^-5 cm²/s to 0.32 × 10^-5 cm²/s and 0.22 × 10^-5 cm²/s, respectively, indicating that the interaction with HA accelerated the migration of polyethylene and polystyrene. These findings highlight the potential environmental hazards posed by MPs in aquatic environments.

A Dye-Assisted Paper-Based Assay to Rapidly Differentiate the Stress of Chlorophenols and Heavy Metals on Enterococcus faecalis and Escherichia coli

Biological toxicity testing plays an essential role in identifying the possible negative effects induced by substances such as organic pollutants or heavy metals. As an alternative to conventional methods of toxicity detection, paper-based analytical device (PAD) offers advantages in terms of convenience, quick results, environmental friendliness, and cost-effectiveness. However, detecting the toxicity of both organic pollutants and heavy metals is challenging for a PAD. Here, we show the evaluation of biotoxicity testing for chlorophenols (pentachlorophenol, 2,4-dichlorophenol, and 4-chlorophenol) and heavy metals (Cu²⁺, Zn²⁺, and Pb²⁺) by a resazurin-integrated PAD. The results were achieved by observing the colourimetric response of bacteria (Enterococcus faecalis and Escherichia coli) to resazurin reduction on the PAD. The toxicity responses of E. faecalis-PAD and E. coli-PAD to chlorophenols and heavy metals can be read within 10 min and 40 min, respectively. Compared to the traditional growth inhibition experiments for toxicity measuring which takes at least 3 h, the resazurin-integrated PAD can recognize toxicity differences between studied chlorophenols and between studied heavy metals within 40 min.

Current research trends on cosmetic microplastic pollution and its impacts on the ecosystem: A review

Since the advent of microplastics, it has become a vital component, directly or indirectly, in our daily lives. With advancements in their use, microplastics have become an integral part of personal care, cosmetics, and cleaning products (PCCPs) and emerged as a domestic source of environmental pollution. Over the years, researchers have ascertained the harmful effects of microplastics on the environment. In this context, the assessment and monitoring of microplastics in PCCPs require considerable attention. In addition, it raises concern regarding the need to develop innovative, sustainable, and environmentally safe technologies to combat microplastic pollution. Therefore, this review is an endeavor to uncover the fate, route and degradation mechanism of cosmetic microplastics. In addition, the major technological advancement in cosmetic microplastic removal and the steps directed toward mitigating cosmetic microplastic pollution are also discussed.

The interaction mechanism of polystyrene microplastics with pharmaceuticals and personal care products

Microplastics (MPs) have been detected in the hydrosphere, with hazardous implications in transporting coexisting water pollutants. Our knowledge about the interaction mechanisms that MPs establish with organic pollutants are still growing, which is essential to understand the adsorption properties of MPs and their relative stability with adsorbates. Here, we used classical (force field methods) and ab-initio (density functional theory) computational chemistry tools to characterize the interaction mechanisms between Polystyrene-MPs (PS-MPs) and pharmaceuticals/personal care products (PPCPs). Adsorption conformations and energies, thermochemistry, binding, and energy decomposition analyses were performed to obtain the quantitative mechanistic information. Our results show that PS-MPs have permanent dipoles, increasing the interaction with neutral PPCPs while repelling the charged pollutants; in all cases, a stable physisorption takes place. Moreover, PS-MPs increase their solubility upon pollutant adsorption due to an increase in the dipole moment, increasing their co-transport ability in aqueous environments. The stability of the PS-MPs/PPCPs complexes is further confirmed by thermochemical and molecular dynamics trajectory analysis as a function of temperature and pressure. The interaction mechanism of high pKa pollutants (pKa > 5) is due to a balanced contribution of electrostatic and dispersion forces, while the adsorption of low pKa pollutants (pKa < 5) maximizes the electrostatic forces, and steric repulsion effects explain their relative lower adsorption stability. In this regard, several pairwise intermolecular interactions are recognized as a source of stabilization in the PS-MPs/PPCPs binding: hydrogen bonding, π-π, OH⋯π, and CH⋯π, CCl⋯CH and CH⋯CH interactions. The ionic strength in solution slightly affects the adsorption stability of neutral PPCPs, while the sorption of charged pollutants is enhanced. This mechanistic information provides quantitative data for a better understanding of the interactions between organic pollutants and MPs, serving as valuable information for sorption/kinetic studies.

Lipophilicity profiling and cell viability assessment of a selected panel of endocrine disruptors

Endocrine disruptors are chemicals widely used worldwide by industries in a variety of applications. Routinely exposure to these chemicals, even if at low doses, can cause damage effects on human health. In the present study, we evaluated toxic effects of nine chemicals, among which phthalates, using various cell lines to inspect their capability to interfere with cell proliferation and viability. Alongside, we investigated their affinity for phospholipids to assess the possible passage through biomembranes. Experimentally determined logk_w^IAM.MG values ranged from 1.37 to 3.49 whilst calculated log k_w^IAM.DD2 spanned from 1.80 to 5.21, supporting the target contaminants to exhibit lipophilicity moderate or very high. The achieved results were related to pharmacokinetic and toxicological properties by ADMET predictor™ and EPI Suite™ software. Triclosan and 4-Nonylphenol were found to be the most toxic against all cell lines screened, showing an IC₅₀ of 30 μM for triclosan on human keratinocytes and of 50 μM for 4-Nonylphenol on human colorectal adenocarcinoma cells. Overall, even if the phthalates showed higher IC₅₀ values (ranging from 170 μM to 280 μM), we can assert that all contaminants herein tested were able to interfere with cell growth and viability.

Heavy metal-mediated adsorption of antibiotic tetracycline and ciprofloxacin on two microplastics: Insights into the role of complexation

Microplastics (MPs) have recently become an emerging environmental concern. Nevertheless, limited information is known about the adsorption of MPs for organic contaminants under combined heavy metals pollution, with an emphasis on the role of complexation. Thus, this study aims to comprehensively compare and investigate the adsorption performance of antibiotic tetracycline (TC) and ciprofloxacin (CIP) on two polar MPs (polyamide (PA) and polyvinyl chloride (PVC)) affected by Cu(II) and Cd(II) with contrasting complexation abilities. Batch adsorption experiments were used in combination with speciation calculation, zeta potential determination, FTIR spectroscopy characterization and investigation of the affinity of MPs for heavy metals. Results showed that the sorption kinetics and isotherms of TC and CIP on PA and PVC could be well fitted to pseudo-second-order and Langmuir models, respectively, both in the absence and presence of Cu and Cd, suggesting that multiple interactions and monolayer adsorption played an important role in the adsorption process. The presence of Cu substantially improved TC and CIP adsorption and obviously changed the pH dependence of their adsorption onto both MPs, which may result from the Cu-induced strong complexation with TC and CIP. The presence of Cd slightly enhanced TC adsorption on both MPs while reduced CIP adsorption especially on PVC, which may be ascribed to the Cd-induced cationic bridging effects in TC adsorption and the competitive adsorption of Cd in CIP adsorption. Therefore, the heavy metal-mediated complexation effects may play a dominant role in antibiotic adsorption by MPs only in the presence of heavy metals with strong complexation ability while the adsorption performance in the presence of heavy metals with negligible complexation capacity may be influenced by effects other than complexation. This study helps further understand the heavy metal-mediated adsorption behavior of organic contaminants on polar MPs and the role of complexation reactions therein.

Interactions of microplastics and soil pollutants in soil-plant systems

In recent years, increasing studies have been reported on characterization and detection of microplastics (MPs), and their interactions with organic pollutants (OPs) and heavy metals (HMs) in soils. However, a comprehensive review on the characteristics and factors that influence MPs distribution in soils, the sorption characteristics and mechanisms of soil contaminants by MPs, especially the interactions of MPs and their complexes with pollutants in the soil-plant systems remains rarely available at present. This review focuses on the sorption features and mechanisms of pollutants by MPs in soil and discussed the effects of MPs and their complexing with pollutants on soil properties, microbe and plants. The polarity of MPs significantly influenced the sorption of OPs, and different sorption mechanisms are involved for the hydrophobic and hydrophilic OPs. The sorption of OPs on MPs in soils is different from that in water. Aging of MPs can promote the sorption and migration of contaminants. The enhanced effects of biofilm in microplastisphere on the sorption of pollutants by MPs are critical, and interactions of soil environment-MPs-microbe-HMs-antibiotics increase the potential pathogens and larger release of resistance genes. The coexistence of HMs and MPs affected the growth of plants and the uptake of HMs and MPs by the plants. Moreover, the type, dose, shape and particle size of MPs have important influences on their interactions with pollutants and subsequent effects on soil properties, microbial activities and plant growth. This review also pointed out some knowledge gaps and constructive countermeasures to promote future research in this field.

Mediterranean microplastic contamination: Israel's coastline contributions

This study provides an analysis of the current state of microplastic (MP) contamination along the Mediterranean coastline of Israel. Six strategic sites were monitored in this study - each representing a unique coastal environment. We conclude that Tel Aviv and Hadera, both located near stream estuaries, were highly contaminated (18,777 particles/m³) with MP compared to the other locations. The MP detected included both secondary MP and pristine polymeric pellets. In-depth characterization of the MP illustrated a large percentage of both fragmented and film MP morphologies and the most common MP polymers were polyethylene and polypropylene. Further particle analysis showed that MPs were contaminated with biofilm, including microorganisms such as diatoms, as well as metal residues. Through the spatial analysis presented herein we suggest that local rivers are significant contributors to MP contamination along the Mediterranean Sea coastline of Israel and may pose a direct threat to environment and human health.

Influence of microplastics on triclosan bioaccumulation and metabolomics variation in Tilapia fish tissues

Microplastics (MPs) and chemical pollutants usually coexist in aquatic environments. The bioaccumulation and metabolism of pollutants in aquatic organisms can be influenced by MPs. In this study, the bioaccumulation of triclosan (TCS) in tilapia tissues was determined, and metabolomics in the liver, gills, and gut were investigated after 10-day exposure to micro-sized polystyrene (PS) and TCS in water. The results showed that TCS bioaccumulated in various tissues, with the highest average concentration of 2728 ± 577 ng g^-1 in the gut. The log bioaccumulation factors (BAFs) for TCS in these tissues were in the range of 0.99-3.56. Compared to the TCS treatment alone, MPs showed enhancement on the bioaccumulation of TCS in tilapia skin, liver, gut, gills, and stomach tissues in the TCS plus MP exposure. Especially in the skin and liver, the TCS concentrations were up to 2.06 and 1.38 times higher in the co-exposure of TCS and MPs, respectively. Based on the metabolomic analysis, MPs mainly disturbed the lipid and energy metabolism in tilapia fish. The altered metabolites between treatment with TCS alone and TCS + MPs were consistent, indicating that TCS has stronger disturbance in lipid and energy metabolism than MPs. This implies that the metabolism influence by the mixture of MPs and compounds is complicated in fish tissues.

Phytotoxicity of polystyrene, polyethylene and polypropylene microplastics on tomato (Lycopersicon esculentum L.)

Despite the fact that microplastic pollution in terrestrial ecosystems has received increasing attention, there are few studies on the potential effects of different microplastics on terrestrial plants. In this study, the toxicity of polystyrene (PS), polyethylene (PE) and polypropylene (PP) microplastics with different concentrations (0, 10, 100, 500 and 1000 mg/L) to tomato (Lycopersicon esculentum L.) were studied by a hydroponic experiment. The results showed that the three microplastics had inhibitory effects on seed germination when the concentration was less than or equal to 500 mg/L, and the inhibition rate ranged from 10.1% to 23.6%. Interestingly, the inhibition effect was alleviated under 1000 mg/L microplastic treatment. Generally, PE was more toxic to seedling growth than PS and PP. Additionally, it was confirmed that microplastics could cause oxidative stress in plants, and PP was relatively less toxic to antioxidant enzymes than PS and PE. These results can provide a theoretical basis and data support for further investigation on the toxicity of microplastics to tomatoes, and contribute to understanding the type specificity of microplastics' toxic effects on plants.

Aging of microplastics increases their adsorption affinity towards organic contaminants

When released in the environment, microplastics undergo surface weathering due to mechanical abrasion and ultraviolet exposure. In this study, the adsorption of two model contaminants, phenanthrene and methylene blue, by weathered high density polyethylene (HDPE) and polypropylene (PPE) was evaluated to understand how the microplastics' aging influences contaminant adsorption. Microplastics were aged through an accelerated weathering process using ultraviolet exposure with or without hydrogen peroxide. Adsorption isotherms were conducted for both contaminants on pristine and aged microplastics. The adsorption of organic contaminants was higher on aged microplastics than on pristine ones, with methylene blue having the highest affinity increase with aging at 4.7-fold and phenanthrene having a 1.9-fold increase compared to the pristine particles. To understand the mechanisms involved with higher adsorption of contaminants by aged microplastics, changes in the specific surface area and surface chemistry of aged microplastics were characterized by Fourier Transform Infrared Spectroscopy, X-ray Photoelectron Spectroscopy, zeta potential, X-ray tomography, and Brunauer-Emmett-Teller krypton adsorption analyses. The results of this study show that oxidation of microplastics can enhance the adsorption of organic contaminants, which may increase their role as vectors of contaminants in the aquatic food chain.