Screening of suspected micro(nano)plastics in the Ebro Delta (Mediterranean Sea)

Bioaccumulation and dietary bioaccessibility of microplastics composition and cocontaminants in Mediterranean mussels

Microplastics (MPLs) are contaminants of emerging concern (CECs) ubiquitous in aquatic environments, which can be bioaccumulated along the food chain. In this study, the accumulation of polyethylene (PE), polystyrene (PS) and polyethylene terephthalate (PET) microplastics (MPLs) of sizes below 63 μm was assessed in Mediterranean mussels (Mytilus galloprovincialis spp). Moreover, the potential of mussels to uptake and bioaccumulate other organic contaminants, such as triclosan (TCS) and per- and polyfluoroalkyl substances (PFASs), was evaluated with and without the presence of MPLs. Then, the modulation of MPLs in the human bioaccessibility of co-contaminants was assessed by in vitro assays that simulated the human digestion process. Exposure experiments were carried out in 15 L marine microcosms. The bioaccumulation and bioaccessibility of PE, PS, PET, and co-contaminants were assessed by means of liquid chromatography -size exclusion chromatography-coupled to high-resolution mass spectrometry (LC(SEC)-HRMS). Our outcomes confirm that MPL bioaccumulation in filter-feeding organisms is a function of MPL chemical composition and particle sizes. Finally, despite the lower accumulation and bioaccumulation of PFASs in the presence of MPLs, the bioaccessibility assays revealed that PFASs bioaccessibility was favoured in the presence of MPLs. Since part of the bioaccumulated PFASs are adsorbed onto MPL surfaces by hydrophobic and electrostatic interactions, these interactions easily change with the pH during digestion, and the PFASs bioaccessibility increases.

Bovine Serum Albumin Bends Over Backward to Interact with Aged Plastics: A Model for Understanding Protein Attachment to Plastic Debris

Plastic pollution, a major environmental crisis, has a variety of consequences for various organisms within aquatic systems. Beyond the direct toxicity, plastic pollution has the potential to absorb biological toxins and invasive microbial species. To better understand the capability of environmental plastic debris to adsorb these species, we investigated the binding of the model protein bovine serum albumin (BSA) to polyethylene (PE) films at various stages of photodegradation. Circular dichroism and fluorescence studies revealed that BSA undergoes structural rearrangement to accommodate changes to the polymer's surface characteristics (i.e., crystallinity and oxidation state) that occur as the result of photodegradation. To understand how protein structure may inform docking of whole organisms, we studied biofilm formation of bacteriaShewanella oneidensison the photodegraded PE. Interestingly, biofilms preferentially formed on the photodegraded PE that correlated with the state of weathering that induced the most significant structural rearrangement of BSA. Taken together, our work suggests that there are optimal physical and chemical properties of photodegraded polymers that predict which plastic debris will carry biochemical or microbial hitchhikers.

Identification and quantification of nanoplastics (20-1000 nm) in a drinking water treatment plant using AFM-IR and Pyr-GC/MS

Nanoplastics, owing to their small particle size, pose a significant threat to creatures, deserving heightened attention. Numerous studies have investigated microplastics pollution and their removal efficiency in drinking water treatment plants, none of which have involved nanoplastics due to lacking a suitable analytical method. This study introduced a feasible method of combing AFM-IR and Pyr-GC/MS to identify and quantify nanoplastics (20-1000 nm) for a preliminary understanding of their fate during drinking water treatment processes. Resolving of chemical functional groups and pyrolysis products from AFM-IR and Pyr-GC/MS data demonstrated the presence of PE and PVC nanoplastics in this drinking water treatment plant. The initial influent abundances of PE and PVC nanoplastics were 0.86 μg/L and 137.31 μg/L, with subsequent increase to 4.49 μg/L and 208.64 μg/L in ozonation contact tank unit. Then a gradual decreasing was observed along water process, achieving 98.4% removal of PE nanoplastics and 44.0% removal of PVC nanoplastics, respectively. Although this drinking water treatment plant has exhibited a certain level of nanoplastics removal efficiency, particular attention should be directed to the oxidation unit, which appears to be a significant source of nanoplastics. This study will lay a foundation for revealing nanoplastics pollution in the environment.

Exposure to micro(nano)plastics polymers in water stored in single-use plastic bottles

Human exposure to micro (nano)plastics (MNPLs) has become a significant concern as a potential health threat. Exposure routes include ingestion, inhalation, and dermal contact, being food and drinking water the primary sources of oral exposure. Here we present the quantification of polymers of MNPLs particles from 700 nm to 20 μm in bottled water commercialised in Spain, including an estimation of the potential risk for daily consumers. We evaluated samples from 20 popular brands in 0.5 and 1.5 L plastic bottles. A double-suspect screening approach developed and validated in our research group for drinking water was adapted for bottled water samples. The identification and quantification of MNPLs-polymers in mass units and the tentative identification of plastic additives (PA) until the second level of confidence was carried out based on high-performance liquid chromatography coupled to high-resolution mass spectrometry (HPLC-HRMS). The results showed the presence of polypropylene (PP), polyethylene (PE) and polypropylene terephthalate (PET) in the samples. Among them, PE was the most frequently detected and quantified polymer (55% of samples) followed by PET which was detected in 33% of the samples and showing the highest concentration (4700 ng L-1). The median value of the sum of polymer concentrations was 359 ng L-1. In addition, 28 plastic additives were detected, where at least one of them was present in 100% of the samples. Stabilizers and plasticisers were the most frequently identified. A prioritisation study was performed using a multi-QSAR modelling software, where bis(2-ethylhexyl) adipate and bis(2-ethylhexyl) phthalate were estimated as the most potentially harmful compounds for human health. Overall, findings suggest that bottled water is a non-negligible route to exposure to MNPLs.

Determination of extractable pollutants from microplastics to vegetables: Accumulation and incorporation into the food chain

The presence and impacts of microplastics (MPs) are being extensively researched and reviewed, especially in the marine environment. However, mobility, transportation routes, and accumulation of leaching compounds such as additives in plastic waste including MPs are scarcely studied. Information regarding ecotoxicity and leachability of compounds related to MPs contamination in the environment is limited. Current work presents the levels of leachates from plastic materials in edible-root and non-edible root vegetables. Samples were analyzed by static headspace and gas chromatography-mass spectrometry (SHS-GC-MS) and the presence of 93 putative compounds was accurately monitored in the samples by the usage of Mass Spectrometry-Data Independent Analysis software. The application of chemometrics to the SHS-GC-MS dataset allowed differentiation between the levels of plastic related compounds in edible root and non-edible root vegetables, the former showing a higher content of plastic leachates. For SHS sampling, 3 g of the sample were incubated at 130 °C for 35 min in the HS vial and toluene and naphthalene were added as internal standards for quantification purposes. The developed SHS-GC-MS methodology is straightforward, reliable, and robust and allowed the quantification of sixteen plastic associated compounds in the samples studied in a range from 0.14 to 28800 ng g-1 corresponding to 2,4-di-tert-butylphenol and p,α-dimethylstyrene, respectively. Several of the quantified compounds pointed out to potential contamination of polystyrene and/or polyvinyl chloride MPs.

Micro(nano)plastics in the atmosphere of the Atlantic Ocean

The occurrence, long-range atmospheric transport and deposition of micro and nano plastics (MNPLs) remains un-quantified for the oceanic atmosphereopen ocean. Here we show the characterisation of MNPLs and the aerosol composition (PM₁₀) in a north-south Atlantic transect from Vigo (Spain) to Punta Arenas (Chile). The analytical procedure to assess the composition of MNPLs consisted of a double suspect screening approach of the polymers and additives, the two constituents of plastics. Polymers were analysed by size exclusion chromatography coupled with high-resolution mass spectrometry using an atmospheric pressure photoionization source operated in positive and negative conditions (HPLC(SEC)-APPI(+/-)-HRMS). Plastic additives were screened with high-performance liquid chromatography coupled to high-resolution mass spectrometry using an electrospray ionisation source (HPLC-ESI(+/-)-HRMS). The most common polymers were polyethylene (PE), polypropylene (PP), polyisoprene (PI), and polystyrene (PS), with the highest polymer concentration being 51.7 ng·m^-3 of PI. The air mass back trajectories showed the variable influence of oceanic and terrestrial air masses. These differences were reflected in the aerosol composition with different contributions of Saharan dust, sea spray aerosol, organic/elemental carbon, and MNPLs. Results showed that samples largely influenced by sea-spray and air masses originating from coastal South America and the north Atlantic subtropical gyre were more contaminated by MNPLs. Moreover, this information was complemented by the characterisation of the largest particles using scanning electron microscopy (SEM) and µ-Fourier Transform Infrared Spectroscopy (µ-FTIR). This work provides the first field evidence of the long-range transport of MNPLs in most of the Atlantic Ocean, as the result of dynamic coupling between the lower atmosphere and the surface ocean. Sea-spray formation arises as a key driver for the aerosolisation of MNPLs, and atmospheric transport followed by dry deposition may modulate the occurrence of MNPLs in large oceanic regions, issues that will require future research efforts.

Nanoplastics potentiate mercury toxicity in a marine copepod under multigenerational exposure

The continuous fragmentation of plastics and release of synthetic nanoplastics from products have been aggravating nanoplastic pollution in the marine ecosystem. The carrier role of nanoplastics may increase the bioavailability and toxicity effects of toxic metals, e.g., mercury (Hg), which is of growing concern. Here, the copepod Tigriopus japonicus was exposed to polystyrene nanoplastics (PS NPs) and Hg (alone or combined) at environmental realistic concentrations for three generations (F0-F2). Then, Hg accumulation, physiological endpoints, and transcriptome were analyzed. The results showed that the copepod's reproduction was significantly inhibited under PS NPs or Hg exposure. The presence of PS NPs caused significantly higher Hg accumulation, lower survival, and lower offspring production in copepods relative to Hg exposure, suggesting an increased threat to the copepod's survivorship and health. From the molecular perspective, combined PS NPs and Hg caused a graver effect on the DNA replication, cell cycle, and reproduction pathways relative to Hg exposure, linking to lower levels of survivorship and reproduction. Taken together, this study provides an early warning of nanoplastic pollution for the marine ecosystem not only because of their adverse effect per se but also their carrier role for increasing Hg bioaccumulation and toxicity in copepods.

Chronic nanoplastic exposure induced oxidative and immune stress in medaka gonad

Nanoplastic (NP) pollution is a global issue because of its widespread occurrence and potential toxicity. Many studies have investigated the impacts of the short-term toxicity of NPs on organisms. Until now, only a few studies have assessed the toxicological effects of prolonged exposure to NPs at low concentrations in fish. In this study, the effects of NPs (nano-polystyrene microspheres, diameter: 100 nm) on immune and oxidative stress response, histopathology, and survival in medaka were evaluated. The effects of different concentrations (0, 10, 10⁴, and 10⁶ particles/L) of nanoplastics were studied in medaka Oryzias latipes after 3 months of exposure. Lysozyme enzyme activity, oxidative stress-related biomarkers (i.e., superoxide dismutase, catalase, and glutathione peroxidase), and malondialdehyde levels were decreased under NP exposure. The gonadal histology showed that high NP exposure (10⁶ particles/L) inhibited the process of spermatogenesis and oogenesis processes, implying delayed maturation of the gonad. Furthermore, the IBR and PCA analysis revealed the potential biotoxicity of NPs and the total survival rate of medaka was significantly reduced due to the long-term exposure to NPs. Overall, prolonged exposure to low concentrations of NPs is harmful to the health of medaka gonads. In the long run, this may threaten the fish reproduction and population, suggesting the need for long-term toxicological studies to predict the aquatic animal health in nature.

Critical assessment of the Kendrick mass defect analysis as an innovative approach to process high resolution mass spectrometry data for environmental applications

The growing application of high resolution mass spectrometry (HRMS) over the last decades has dramatically improved our knowledge about the occurrence of environmental contaminants. However, most of the compounds detected remain unknown and the large volume of data generated requires specific processing approaches. Therefore, this study presents the concepts of mass defect (MD), Kendrick mass (KM) and Kendrick mass defect (KMD) to the expert and non-expert reader along with relevant examples of applications in environmental HRMS data processing. A preliminary bibliometric overview indicates that the potential benefits of KMD analysis are rather overlooked in environmental science. In practice, a simple calculation allows transforming a mass from the IUPAC system (normalized so that the mass of ¹²C is exactly 12) to its corresponding KM normalized on a specific moiety such as CH₂ (the mass of CH₂ is exactly 14). Then, plotting the KMD according to the nominal KM allows revealing groups of compounds that differ only by their number of CH₂ moieties. For instance, data processing using KM and KMD was proven particularly useful to characterize natural organic matter in a sample, to reveal the occurrence of polymers as well as poly/perfluorinated alkylated substances (PFASs), and to search for transformation products (TPs) of a given chemical.

Assessment of Micro- and Nanoplastic Composition (Polymers and Additives) in the Gastrointestinal Tracts of Ebro River Fishes

One of the main routes of fish exposure to micro- and nanoplastics (MNPLs) is their ingestion. MNPLs can act as reservoirs of organic contaminants that are adsorbed onto their surfaces, or that can leach from their complex formulations, with potential impacts on biota and along the aquatic food chain. While MNPLs have been reported in fishes worldwide, complete information on MNPL compositions, polymers and additives continues to be scarce. In this work, the presence of MNPLs in the gastrointestinal tracts (GIT) of fish from the Ebro River (Spain) was investigated using a double suspected screening approach to assess and quantify polymers and additives. The sample-preparation procedure consisted of sequential alkaline and acidic digestions with KOH and HNO₃, followed by ultrasonic-assisted extraction (USAE) with toluene. The analysis of polymers was carried out with size-exclusion chromatography followed by high-resolution mass spectrometry using an atmospheric pressure photoionization source, operating in negative and positive ionisation modes (SEC-(±)-APPI-HRMS) using full-scan acquisition (FS). Plastic additives were assessed using high-performance liquid chromatography with a C18 analytical column coupled to HRMS equipped with an electrospray ionisation source operating under positive and negative conditions (LC-(±ESI)-HRMS). The acquisition was performed in parallel with full-scan (FS) and data-dependent scan (ddMS²) modes, working under positive and negative ionisation modes. The polymers most frequently detected and quantified in fish GITs were polysiloxanes, polyethylene (PE), polypropylene (PP) and polystyrene (PS). PE was detected in 84% of the samples, with a concentration range from 0.55 to 3545 µg/g. On the other hand, plasticisers such as phthalates and stabilisers such as benzotriazoles were the most frequently identified plastic additives.

A holistic assessment of the sources, prevalence, and distribution of bisphenol A and analogues in water, sediments, biota and plastic litter of the Ebro Delta (Spain)

Bisphenol A (BPA) is one of the main ubiquitous compounds released from plastics in the environment. This compound, considered an endocrine disruptor, poses a risk to aquatic wildlife and human population, being included in multiple environmental monitoring programmes. Following the regulations restricting BPA use in the last years, BPA-like chemicals have been produced and used as BPA substitutes. However, they are not commonly included in monitoring programs yet and their presence is thus misrepresented, despite showing similar endocrine disrupting potential. In this work, an analytical method for analysing bisphenol A and five of its analogues (Bisphenol S, B, F, AF and Tetrabromobisphenol A) is described, validated for water (riverine, sea and wastewater), sediment, and biota (fish and biofilm) and applied to monitor their presence in the Ebro River Delta (NE Spain). In addition, plastic litter was also collected to evaluate their role as potential source of bisphenols. All compounds except BPF were detected in the analysed samples. Wastewater treatment plants (WWTPs) were discarded as major sources of BPs into the natural aquatic environment, as no BPs were detected in treated effluents. Indeed, the high levels of BPs in the natural environment could be related with direct discharge of raw wastewater from small rural population nucleus. The analysis of riverine plastic leachates yielded 4 out of the 6 BPs analysed, strengthening the hypothesis that plastic debris are also a source of BPs in the natural environment. Whereas Bisphenol S and BPA were detected in water and, to a limited extent, in biota, less polar analogues (mainly BPAF and TBBPA) were not found in any of the water samples. Instead, these hydrophobic BPs were found in fish tissues and biofilm, pointing out plastics and microplastics as their possible vectors. Finally, biofilm demonstrated its potential as sentinel of chemical contamination in freshwater environment.

Nanoplastics are bioaccumulated in fish liver and muscle and cause DNA damage after a chronic exposure

The extent of the widespread, planetary contamination by plastic waste is difficult to fully capture. Nanoplastics (NPs) are currently in the center of research concerning plastic litter, both for the analytical challenges they pose and for their potential to provoke hazardous effects in organisms. However, there are still many unanswered questions in this multidisciplinary field, with a crucial missing piece being the quantification of NPs in fish tissues after in vivo exposures. Another relevant question that is still greatly unexplored is how a chronic exposure to NPs will affect fish health. This study aims to provide answers to both of these relevant knowledge gaps. To this end, goldfish (Carassius auratus) were exposed to 44 nm polystyrene (PS)-NPs via water for 30 days. Following the exposure, gastrointestinal tract, liver and muscle were sampled for PS-NPs analysis by means of size exclusion chromatography coupled to high resolution mass spectrometry. PS-NPs were detected in all liver and muscle samples of exposed fish, with higher concentrations in liver than in muscle, whereas no PS-NPs were detected in the gastrointestinal tract. Nevertheless, exposure to PS-NPs did not induce changes in hematology parameters nor in cortisol and glucose levels in plasma. On the other hand, even a relatively low concentration of PS-NPs was able to cause DNA damage, measured by an increase in erythrocyte nuclear abnormalities, suggesting that PS-NPs can reach the cell nucleus and cause genotoxicity. These results show for the first time that PS-NPs find their way to fish muscle after chronic exposure, where they bioaccumulate, but do not alter fish survival nor hematological or physiological stress indicators. The accumulation of PS-NPs in fish muscle can represent a threat to human health as a possible route of exposure to small-sized plastics. The present results in a model fish species open windows for future studies in edible fish species.

Personal protective equipment (PPE) pollution driven by the COVID-19 pandemic along the shoreline of Lake Tana, Bahir Dar, Ethiopia

Personal protective equipment (PPE) pollution has become one of the most pending environmental challenges resulting from the pandemic. While various studies investigated PPE pollution in the marine environment, freshwater bodies have been largely overlooked. In the present study, PPE monitoring was carried out in the vicinity of Lake Tana, the largest lake in Ethiopia. PPE density, types, and chemical composition (FTIR spectroscopy) were reported. A total of 221 PPEs were identified with a density ranging from 1.22 × 10^-5 PPE m^-2 (control site S1) to 2.88× 10^-4 PPE m^-2 with a mean density of 1.54 × 10^-4 ± 2.58 × 10^-5 PPE m^-2. Mismanaged PPE waste was found in all the sampling sites, mostly consisting of surgical face masks (93.7%). Statistical analyzes revealed significantly higher PPE densities in sites where several recreational, touristic, and commercial activities take place, thus, revealing the main sources of PPE pollution. Furthermore, polypropylene and polyester fabrics were identified as the main components of surgical and reusable cloth masks, respectively. Given the hazard that PPEs represent to aquatic biota (e.g., entanglement, ingestion) and their ability to release microplastics (MPs), it is necessary to implement sufficient solid waste management plans and infrastructure where lake activities take place. Additionally, local authorities must promote and ensure sustainable tourism in order to maintain the ecosystems in Lake Tana. Prospective research priorities regarding the colonization and degradation of PPE, as well as the release of toxic chemicals, were identified and discussed.

Microplastics in the environment: Sampling, pretreatment, analysis and occurrence based on current and newly-exploited chromatographic approaches

The omnipresent character of microplastics (MPs) in environmental matrices, organisms and products has recently posed the need of their qualitative as well as quantitative analysis imperative, in order to provide data about their abundance and specification of polymer types in several substrates. In this framework, current and emerging approaches based on the chromatographic separation are of increased relevance in the field of MPs analysis and possess a large number of merits, since most of them are applicable in various complex matrices, sensitive and ideal for the detection of small-sized particles, whereas the common absence of any special pre-treatment step before analysis should also be highlighted. Αnalytical pyrolysis coupled with gas chromatography mass spectrometry (GC-MS) has recently gained ground as a powerful means to deliver information on MPs composition and degradation after their release into environment. Several instrumentations and trends in the area of analytical pyrolysis are thoroughly described within this review, while newly-exploited chromatographic methods in the field of MPs analysis, including Liquid Chromatography (LC) and Gel Permeation Chromatography (GPC) in this line are also investigated. The present review fills the gap of standardization concerning sampling, pre-treatment and chromatographic approaches and gathers all the available methodologies applied inside this area in accordance with the studied substrate, with the most examined environmental matrices being the solid one. After investigating the various works, some development options arise and it appears that chromatographic approaches should focus on improved extraction processes in terms of MPs isolation, since it is a crucial part in plastic items monitoring and is commonly depended on the polymer type and matrix. Special attention is given on the potential of chromatographic techniques for microplastics identification as well as quantification by confirming the current research status and knowledge gaps and highlighting some of the recent trends in this field.

Short-term exposure to polymethylmethacrylate nanoplastics alters muscle antioxidant response, development and growth in Sparus aurata

Polymethylmethacrylate (PMMA) plastic fragments have been found abundant in the environment, but the knowledge regarding its effects on the physiology of aquatic animals is still poorly studied. Here the short-term (96 h) effects of waterborne exposure to PMMA nanoplastics (PMMA-NPs) on the muscle of gilthead sea bream (Sparus aurata) fingerlings was evaluated at a concentration range that includes 0.001 up to 10 mg/L. The expression of key transcripts related to cell stress, tissue repair, immune response, antioxidant status and muscle development, together with several biochemical endpoints and metabolic parameters. Results indicate that exposure to PMMA-NPs elicit mildly antioxidant responses, enhanced the acetylcholinesterase (AChE) activity, and inhibited key regulators of muscle development (growth hormone receptors ghr-1/ghr-2 and myostatin, mstn-1 transcripts). However, no effects on pro-inflammatory cytokines (interleukin 1β, il1β and tumor necrosis factor α, tnfα) expression nor on the levels of energetic substrates (glucose, triglycerides and cholesterol) were found.

Leaching and extraction of additives from plastic pollution to inform environmental risk: A multidisciplinary review of analytical approaches

Plastic pollution is prevalent worldwide and has been highlighted as an issue of global concern due to its harmful impacts on wildlife. The extent and mechanism by which plastic pollution effects organisms is poorly understood, especially for microplastics. One proposed mechanism by which plastics may exert a harmful effect is through the leaching of additives. To determine the risk to wildlife, the chemical identity and exposure to additives must be established. However, there are few reports with disparate experimental approaches. In contrast, a breadth of knowledge on additive release from plastics is held within the food, pharmaceutical and medical, construction, and waste management industries. This includes standardised methods to perform migration, extraction, and leaching studies. This review provides an overview of the approaches and methods used to characterise additives and their leaching behaviour from plastic pollution. The limitations of these methods are highlighted and compared with industry standardised approaches. Furthermore, an overview of the analytical strategies for the identification and quantification of additives is presented. This work provides a basis for refining current leaching approaches and analytical methods with a view towards understanding the risk of plastic pollution.

Wide-scope screening of pharmaceuticals, illicit drugs and their metabolites in the Amazon River

Only a limited number of households in the Amazon are served by sewage collection or treatment facilities, suggesting that there might be a significant emission of pharmaceuticals and other wastewater contaminants into freshwater ecosystems. In this work, we performed a wide-scope screening to assess the occurrence of pharmaceuticals, illicit drugs and their metabolites in freshwater ecosystems of the Brazilian Amazon. Our study included 40 samples taken along the Amazon River, in three of its major tributaries, and in small tributaries crossing four important urban areas (Manaus, Santarém, Macapá, Belém). More than 900 compounds were investigated making use of target and suspect screening approaches, based on liquid chromatography coupled to high-resolution mass spectrometry with ion mobility separation. Empirical collision-cross section (CCS) values were used to help and confirm identifications in target screening, while in the suspect screening approach CCS values were predicted using Artificial Neural Networks to increase the confidence of the tentative identification. In this way, 51 compounds and metabolites were identified. The highest prevalence was found in streams crossing the urban areas of Manaus, Macapá and Belém, with some samples containing up to 30 - 40 compounds, while samples taken in Santarém showed a lower number (8 - 11), and the samples taken in the main course of the Amazon River and its tributaries contained between 1 and 7 compounds. Most compounds identified in areas with significant urban impact belonged to the analgesics and antihypertensive categories, followed by stimulants and antibiotics. Compounds such as caffeine, cocaine and its metabolite benzoylecgonine, and cotinine (the metabolite of nicotine), were also detected in areas with relatively low anthropogenic impact and showed the highest total prevalence. This study supports the need to improve the sanitation system of urban areas in the Brazilian Amazon and the development of follow-up studies aimed at quantifying exposure levels and risks for Amazonian freshwater biodiversity.

Current Progress on Marine Microplastics Pollution Research: A Review on Pollution Occurrence, Detection, and Environmental Effects

Recently, microplastics pollution has attracted much attention in the environmental field, as researchers have found traces of microplastics in both marine and terrestrial ecological environments. Here, we reviewed and discussed the current progress on microplastics pollution in the marine environment from three main aspects including their identification and qualification methods, source and distribution, and fate and toxicity in a marine ecosystem. Microplastics in the marine environment originate from a variety of sources and distribute broadly all around the world, but their quantitative information is still lacking. Up to now, there have been no adequate and standard methods to identify and quantify the various types of microplastics, which need to be developed and unified. The fate of microplastics in the environment is particularly important as they may be transferred or accumulated in the biological chain. Meanwhile, microplastics may have a high adsorption capacity to pollutants, which is the basic research to further study their fate and joint toxicity in the environment. Therefore, all the findings are expected to fill the knowledge gaps in microplastics pollution and promote the development of relative regulations.

Organic Contaminants and Interactions with Micro- and Nano-Plastics in the Aqueous Environment: Review of Analytical Methods

Micro- and nanoplastic particles are increasingly seen not only as contaminants themselves, but also as potential vectors for trace organic chemicals (TOrCs) that might sorb onto these particles. An analysis of the sorbed TOrCs can either be performed directly from the particle or TOrCs can be extracted from the particle with a solvent. Another possibility is to analyze the remaining concentration in the aqueous phase by a differential approach. In this review, the focus is on analytical methods that are suitable for identifying and quantifying sorbed TOrCs on micro- and nano-plastics. Specific gas chromatography (GC), liquid chromatography (LC) and ultraviolet-visible spectroscopy (UV-VIS) methods are considered. The respective advantages of each method are explained in detail. In addition, influencing factors for sorption in the first place are being discussed including particle size and shape (especially micro and nanoparticles) and the type of polymer, as well as methods for determining sorption kinetics. Since the particles are not present in the environment in a virgin state, the influence of aging on sorption is also considered.