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Current opinion: What is a nanoplastic?
Abstract
Abstract With the large amount of attention being given to microplastics in the environment, several researchers have begun to consider the fragmentation of plastics down to lower scales (i.e., the sub-micrometer scale). The term “nanoplastics” is still under debate, and different studies have set the upper size limit at either 1000 nm or 100 nm. The aim of the present work is to propose a definition of nanoplastics, based on our recently published and unpublished research definition of nanoplastics. We define nanoplastics as particles unintentionally produced (i.e. from the degradation and the manufacturing of the plastic objects) and presenting a colloidal behavior, within the size range from 1 to 1000 nm.
... The worldwide growing amount of plastic waste has paved the way for plastics to enter soil (Bläsing & Amelung, 2018). Plastic particles can be differentiated upon their particle size into mesoplastics (MePs; size >5 mm), microplastics (MPs; size <5 mm) and nanoplastics (NPs; size <1000 nm) (Gigault et al., 2018;Hartmann et al., 2019). However, the upper size limit of MePs is still under debate and conflicts with the terminology of plastic litter and macroplastics (Hartmann et al., 2019), similar to a missing consent of the lower size limit of MPs reported between 100 and 1000 μm (Gigault et al., 2018). ...
... Plastic particles can be differentiated upon their particle size into mesoplastics (MePs; size >5 mm), microplastics (MPs; size <5 mm) and nanoplastics (NPs; size <1000 nm) (Gigault et al., 2018;Hartmann et al., 2019). However, the upper size limit of MePs is still under debate and conflicts with the terminology of plastic litter and macroplastics (Hartmann et al., 2019), similar to a missing consent of the lower size limit of MPs reported between 100 and 1000 μm (Gigault et al., 2018). A meta-study revealed that the majority of agricultural and horticultural sites exposed to sewage sludge and mulching film application featured MPs particles (P) counts of up to 13,000 P kg À1 and MPs mass of up to 4.5 mg kg À1 dry soil (Büks & Kaupenjohann, 2020). ...
Extraction of plastic particles from soil is challenging and, thus, exceptionally little spatial information on plastic distribution at the field scale has been gathered. However, for environmental risk assessment, adequate sampling should complement coherent plastic profiling. In this study, we investigated the spatial distribution of mesoplastics (MePs; from >5 mm up to 130 mm) in arable soil (Haplic Cambisol) managed intensively by 12 years of compost application. Geo‐referenced samples ( n = 128) and five different sampling designs ( n = 45) of variable sampling volume (from 2 to 300 L) were collected at a three hectare study site in Northern Germany (0–30 cm soil depth). Soil properties such as pH and soil organic carbon (SOC) were measured to evaluate dispersion measures of these data. In total, we found 259 MePs with a predominance of transparent packaging foils made of polyethylene and coloured fibres of polypropylene. Average particle metrics were a projection area of 47 (3–400) mm ² , a Feret diameter of 18.5 (5.4–130) mm and a mass of 1.89 (0.11–221) mg. Caution is advised when measuring the particle mass due to still strongly adhering soil material, especially for fibre bundles with 0.544 mg soil mg ⁻¹ particle. We recommend using a 0.1 mol L ⁻¹ tetrasodium pyrophosphate solution to purify MePs by removing attached soil before weighing for further environmental risk assessment. The MePs count with a median value of 0.50 (0–3.2) particles kg ⁻¹ and median mass of 2.26 (0–221) mg kg ⁻¹ featured the highest coefficient of variation (CV) with 103% and 187%, respectively. This is 10–20 times larger in comparison to the CV of SOC (9.2%) and even 50–93 times larger than CV of soil pH (2.2%). This leads to the need of larger sample numbers to delineate plastic metrics in comparison with soil properties to identify a reliable mean value of the field within a predefined allowable error. Mesoplastics in the soil were characterized by a pure nugget effect variogram (no spatial correlation), revealed no intrafield variability and the sample volume yielded inconclusive results. Sampling for plastics in soil should either (i) drastically increase the sample number for a single field or (ii) communicate transparently that the allowable error is by far enhanced in comparison with classical soil properties like pH and SOC. More systematic studies featuring geo‐spatial analysis of MePs and smaller‐sized plastics in soils are required to propose adequate sampling designs across multiple land uses and plastics fingerprints. A larger database would, thereupon, pave the way for best‐practice guides on how to treat ‘outliers’ and search for robust estimators for spatial mapping of plastics in soils.
... However, researchers currently debate that the origin of NPs as well as physical characteristics (e.g. colloidal behavior) should also be included in the NP definition because of fundamental differences in potential exposures (Gigault et al. 2018) and thereby risks. In this paper we are defining NP based on size alone (i.e., 1 nm to 1,000 nm), but note the limitations of this definition. ...
... LC50s were presented for D. magna and ranged from 7.7x10 9 items/mL to 1.07x10 10 items/mL (Kim 2017). These toxicity tests were performed with polystyrene spheres; use of polystyrene spheres is criticized since they do not exhibit comparable behavior to NPs of secondary manufacturing origin and therefore may not be representative of NP exposures (Gigault et al. 2018). Therefore, use of manufactured spheres in bioassays presents an interpretive data gap for environmentally relevant systems. ...
There is international focus on global plastic pollution and the subsequent weathering and distribution of microplastics (MPs) and nanoplastics (NPs) in the environment, including human health and ecological concerns. Consequently, there is a rapidly growing body of data reporting environmental exposures (e.g., particle concentrations, size, shape, etc.) and ecotoxicological effects data. However, there is a need to capture and communicate this information for freshwater and marine environments to appropriately inform potential risks and actionable decisions. The U.S. Army Corps of Engineers (USACE) is responsible for dredging and disposing or beneficially utilizing several hundred million cubic yards of shoaled sediments annually. Yet, no clear strategy exists to inform plastic risks in shoaled sediments that require dredging. Therefore, the USACE needs decision frameworks, tools and approaches to proactively address detection, exposure and hazard to communicate the relative risks associated with MPs and NPs in dredged sediments. The objectives of this research are to conduct a literature review of 1) MP and NP occurrence and abundance in sediments relevant to dredging operations, 2) ecotoxicity data associated with MP and NP exposures to organisms of interest for dredged sediment evaluations. Median MP sediment concentrations reported in aquatic ecosystems from lowest to highest were: natural lakes and reservoirs (89 items/kg) < estuarine (196 items/kg) < riverine (273 items/kg) < marine (357 items/kg) < Great Lakes (1,716 items/kg). To better understand the relative sensitivities of organisms commonly used in dredging evaluations, the reviewed ecotoxicological data (e.g., lowest observed effect concentrations (LOECs) and lethal median concentrations (LC50s)) were used to calculate species sensitivity distributions of five invertebrates and one green alga. Based on species sensitivity distributions, the most to least sensitive organisms were Palaemonetes pugio (grass shrimp) > Ceriodaphnia dubia (Cladoceran Crustacean) = Hyalella azteca (Amphipod Crustacean) > Daphnia pulex (Cladoceran Crustacean) > Raphidocelis subcapitata (green algae) > Daphnia magna (Cladoceran Crustacean). Notable data gaps exist for MPs and NPs including limited ecotoxicity data for marine species, NP concentrations in sediments and NP ecotoxicity data. The results from this literature review are the first step towards development of proactive communication tools and decision support documents for MP and NP contamination in dredged sediment.
... Micro-and nano-plastics originate from various sources, including cosmetics, industrial processes, agriculture, sewage systems, packaging, and medical devices [4]. Microplastics are particles with sizes ranging from 100 nm to 5 mm, while those smaller than 100 nm are referred to as nanoplastics [5,6]. Micro-and nano-plastics enter the soil and groundwater via weathering, precipitation, runoff, and erosion, posing threats to human and aquatic health, crops, and drinking water sources [7,8]. ...
The widespread use of nanoplastics inevitably contributes to pollution in aquatic environments and soils. Therefore, it is crucial to understand how these particles migrate in soils with diverse organic matter. This study investigated the effects of low-molecular-weight organic acids (LMWOAs) on the migration of polystyrene nanoplastics (PS-NPs) in goethite-coated quartz sand. The experiments utilized two organic acids, propanoic acid (PA) and tartaric acid (TA), under varying aqueous conditions, including pH levels (4.0, 7.0), ionic strengths (1 mM, 10 mM), and cations (Na+, Ca2+, Ba2+). The experimental results indicated that with the presence of Na⁺, organic acids promoted the migration of PS-NPs through electrostatic forces and steric hindrance, with TA having a greater effect than PA. When pH < pHpzc, increased concentrations of positively charged goethite coating provided favorable deposition sites for the negatively charged PS-NPs, thereby increasing their deposition. Using the DLVO theory, low pH and high ionic strength (IS) decreased the energy barriers between PS-NPs and porous media, whereas high pH and low IS increased these barriers, thus enhancing PS-NPs transport. Divalent cations Ca2+ and Ba2+ enhanced the migration of PS-NPs through complex-forming and -bridging agents. These findings offered significant insights for predicting and analyzing the migration behavior of plastic nanoparticles.
... For the sake of clarity it is important to stress that plastic particles are considered MPs if their larger dimension is <5 mm with a lower boundary of 1 µm below which, they are referred to as nanoplastics (NP) (GESAMP, 2019;Gigault et al., 2018). ...
... The concept of microplastics (MPs) was first raised in 2004 by Thompson et al., University of Plymouth, and it has emerged as a global environmental problem that demands urgent addressing [2]. Nanoplastics (NPs) are small-sized plastic particles with a preliminarily defined size range of 1 nm to 1 μm, which were usually derived from the degradation of raw plastics [3]. Compared with MPs with a size of less than 5 mm, NPs have a large specific surface area and good migration features, causing serious environmental ecological problems and health risks [4][5][6][7]. ...
An unlabeled electrochemical sensing strategy based on electroactive copper-centered metal–organic framework (Cu-MOF) film coupled with multiwalled carbon nanotubes (MWCNTs) was proposed for the rapid assessment of nanoplastic concentration. The sensing interface was fabricated via the electro-deposition of Cu-MOF on the pre-modified MWCNTs using the cathodic reduction method. The exposed copper active sites in Cu-MOF showed excellent electrochemical activity, which was further enhanced due to rapid electron transfer induced by highly conductive MWCNTs. Through the adsorption functionality of Cu-MOF film towards polystyrene (PS) nanoplastics, the rapid recognition for nanoplastics in aqueous solution was achieved, thereby causing the inhibition of the current response. The results showed a robust dependence of the inhibition rate on the PS mass concentration. The proposed detection method was used for the quantitative determination of PS nanoplastics with the sizes of 100 nm, 500 nm, and 1 μm. The applicability of this electrochemical sensing platform was successfully validated in real-world water sample analysis.
Graphical abstract
... NPs are often understood in analogy to nanomaterials as solid plastic particles with one or more external dimensions in the size range of 1-100 nm [8]. However, also an upper size limit of 1000 nm has been suggested [9]. Hartmann et al. [6] proposed a comprehensive framework for defining and categorizing plastic debris taking into account four classifiers, namely origin, size, shape and color. ...
Background
Human exposure to micro- and nanoplastic particles (MNPs) is inevitable but human health risk assessment remains challenging for several reasons. MNPs are complex mixtures of particles derived from different polymer types, which may contain plenty of additives and/or contaminants. MNPs cover broad size distributions and often have irregular shapes and morphologies. Moreover, several of their properties change over time due to aging/ weathering. Case-by-case assessment of each MNP type does not seem feasible, more straightforward methodologies are needed. However, conceptual approaches for human health risk assessment are rare, reliable methods for exposure and hazard assessment are largely missing, and meaningful data is scarce.
Methods
Here we reviewed the state-of-the-art concerning risk assessment of chemicals with a specific focus on polymers as well as on (nano-)particles and fibres. For this purpose, we broadly screened relevant knowledge including guidance documents, standards, scientific publications, publicly available reports. We identified several suitable concepts such as: (i) polymers of low concern (PLC), (ii) poorly soluble low toxicity particles (PSLT) and (iii) fibre pathogenicity paradigm (FPP). We also aimed to identify promising methods, which may serve as a reasonable starting point for a test strategy.
Results and conclusion
Here, we propose a state-of-the-art modular risk assessment framework for MNPs, focusing primarily on inhalation as a key exposure route for humans that combines several integrated approaches to testing and assessment (IATAs). The framework starts with basic physicochemical characterisation (step 1), followed by assessing the potential for inhalative exposure (step 2) and includes several modules for toxicological assessment (step 3). We provide guidance on how to apply the framework and suggest suitable methods for characterization of physicochemical properties, exposure and hazard assessment. We put special emphasis on new approach methodologies (NAMs) and included grouping, where adequate. The framework has been improved in several iterative cycles by taking into account expert feedback and is currently being tested in several case studies. Overall, it can be regarded as an important step forward to tackle human health risk assessment.
... While the impact of microplastic pollution has been extensively researched, the emergence of nanoplastics introduces a newer dimension that warrants thorough investigation. Nanoplastics are characterized by their diminutive size ranging from 1 to 100 nm and are challenging to research due to their microscopic nature (Gigault et al. 2018). Unlike microplastics, these minuscule particles can penetrate biological barriers with relative ease, potentially breaking through cell membranes and inducing alterations at the cellular and molecular levels (L. ...
Nanoplastics have become a growing concern due to their potential impact on freshwater vegetation. The uptake, translocation, and effects of 0.05-µm nanoplastics on Myriophyllum sp. “Roraima” were investigated, along with the role of aerenchyma in nanoplastic transport. Microscopic observations revealed nanoplastic particle adsorption to the plant surface and entry into the roots and stems, with higher abundance and more dispersed distribution by direct contact. Nanoplastic particles were detected in the plant stem, primarily concentrated in regions adjacent to the aerenchyma. No morphological effects were observed. Induced changes in photosynthesis, including increased maximum quantum efficiency of photosystem II (Fv/Fm), decreased non-photochemical quenching (NPQ), decreased photosynthetic pigments, and increased photoprotective pigments, were recognized. Additionally, hydrogen peroxide levels and antioxidant enzyme activities varied in response to nanoplastic exposure. This study provides insights into the impact of nanoplastics on Myriophyllum sp. “Roraima” and has reviewed the underlying mechanisms, highlighting the role of aerenchyma in nanoplastic transport within the plant. Moreover, this study contributes to the understanding of the potential impacts of nanoplastic pollution on freshwater macrophytes while acknowledging the influence of phyto-anatomical structure on nanoplastic translocation.
... Microplastics are pieces of plastic debris in the environment that are smaller than 5 mm and nano plastics are smaller than 1 μm [5]. They can be grouped into primary and secondary groups and come from several different sources. ...
Purpose of Review
The physical health impacts of microplastics have received increasing attention in recent years. However, limited data impedes a full understanding of the internal exposure to microplastics, especially concerning the musculoskeletal system. The purpose of this review is to summarize the recent literature regarding the effects of microplastics on the musculoskeletal system.
Recent Findings
Microplastics have been shown to cause abnormal endochondral ossification and disrupt the normal function of pre-osteoblasts, osteocyte-like cells, and pre-osteoclasts through gene mutations, endoplasmic reticulum stress induction, and reduced autophagosome formation in bone growth areas. Although there are few reports on their effects on muscle, it has been noted that microplastics inhibit energy and lipid metabolism, decrease type I muscle fiber density, impair muscle angiogenesis, cause muscle atrophy, and increase lipid deposition.
Summary
Only a few recent studies have shown that microplastics interfere with the normal function of bone growth-related cells and reduce muscle mass and quality. This review underscores the need for further research into other parts of the musculoskeletal system and studies using human tissues at the disease level.
... The plastic debris found daily in the environment will then undergo strong physicochemical constraints inducing transformations inherent to the environment and to the material such as photodegradation, thermal degradation, biodegradation resulting in fragmentation (Zhang et al., 2021). This fragmentation leads to the formation of micrometric-sized debris, called "microplastics" (MPs), whose size is less than 5 mm (Gigault et al., 2016), and also of "nanoplastics" (NPs), whose size ranges from 1 to 1000 nm (Gigault et al., 2018;Suhrhoff and Scholz-Böttcher, 2016). ...
... However, we also have to acknowledge the potential limitation due to the relatively small sampling size, single exposure conditions, as well as the specific physical condition and developmental stage for zebrafish individuals. Given the easier translocation of nanoplastics (NPs, here defined as ≤ 1 μm) (Gigault et al., 2018), fish guts may not be the optimal indicator organs in exploring NPs' contaminants. In consequence, it is of great important for future studies accounting for both multiple fish species (different trophic levels, developmental stage, and habitat preference) and plastics (various size, shape, color, and chemical composition) to test and broaden our findings. ...
... Microplastics (MP) have all the features mentioned to be in the group of worrisome pollutants, the most important of which is the presence of this pollutant in water environments [1]. ...
Microplastic pollution is a growing environmental concern globally, attracting significant attention due to its potential impacts on aquatic ecosystems. This short review aims to provide a comprehensive overview of the research conducted on microplastic pollution in fish, focusing on its occurrence, sources, impacts, and potential mitigation strategies. By analyzing existing studies, this review highlights the urgent need for continued research and increased awareness to address this persistent issue.
... By 2025, an estimated 11.0 billion tons of plastic will have accumulated in the environment [7], potentially excluding single-use plastics produced during COVID-19 pandemic [8]. Environmental plastic debris undergoes chemical and physical processes, breaking down into microplastics (<5 mm) or nanoplastics (NPs, <100 nm) [9][10][11]. As NPs proliferate, they increasingly enter the ...
Globally, plastic pollution threatens human health, particularly affecting the hearts of offspring exposed to maternal environmental factors early in development. Few studies have specifically addressed sex-specific cardiac injury in offspring resulting from maternal exposure to polystyrene nanoplastics (PS-NPs). This study investigates the potential cardiac injury in offspring following maternal exposure to 1 mg/L PS-NPs. Pregnant C57BL/6J mice were exposed to PS-NPs until 3 weeks postpartum to establish a maternal exposure model. Heart tissues were collected and weighed, and the transcriptomes of the offspring hearts were sequenced and analyzed using high-throughput RNA sequencing. Immunohistochemical staining was performed to assess the effects of PS-NPs on cardiac immune infiltration, fibrosis, and apoptosis in the offspring. PS-NPs caused a significant reduction in heart and body weight in female offspring compared to males. Additionally, PS-NPs induced sex-specific transcriptional reprogramming and metabolic disruptions in the offspring. PS-NPs also induced significant fibrosis, apoptosis, and increased CD68⁺ macrophage infiltration in offspring hearts. Notably, PS-NPs induced distinct cardiovascular diseases in the offspring. Fluid shear stress and atherosclerosis were significantly enriched in PS-NP-treated male offspring, while viral myocarditis was predominantly enriched in PS-NP-treated females. Our findings suggest that PS-NPs induce cardiotoxicity in offspring by disrupting metabolism, impairing immunity, and triggering fibrosis and apoptosis, with sex-specific differences. This study provides novel insights and a foundation for understanding sex-specific pharmacological differences and interventions in PS-NP-induced cardiovascular disease in offspring.
The distribution of micro‐ and nanoplastics (MNPs) in the environment is increasingly becoming a cause of concern for human health. The small size of these particles makes them prone to accumulate not only in the tissues of various organs but also enables them to enter cells and act as carriers of external materials and microbes. Since environmental pollutants influence both male and female reproductive function and foetal development, it is expected that this also applies to MNPs, as they can easily accumulate in reproductive organs. This highlights the potential risks associated with MNPs and the need for further research in this area. In the female reproductive system, the ovary plays a crucial role in producing oocytes. The SK‐OV‐3 human ovarian cancer cell line represents an epithelial‐like model for ovarian cells, and it has been widely used in nanomedicine and nanotoxicological studies. In the present study, x‐ray fluorescence (XRF) microscopy was used to investigate the accumulations of model polyvinyl chloride (PVC) nanoplastics (NPs), labelled with cadmium‐selenide quantum dots (CdSe‐QDs), in SK‐OV‐3 cells at sub‐micrometric spatial resolution. The Cd and Se QDs components distribution and the Cl of PVC were successfully used to track the NPs and to confirm that NPs do not leach the QDs, while endogenous elements such as Na, Mg, S and P were also monitored to investigate potential biochemical changes attributed to NPs toxicity. Our study suggests that nanoplastics made of PVC can accumulate in ovarian cells, even if they appear less incline than in other types of cells, such as macrophages. Moreover, our results demonstrate that XRF analyses are a useful tool for biological studies aimed at deepening our understanding on the toxicological mechanisms of pollutants on human fertility.
This review offers an in‐depth exploration of current strategies for recycling plastic waste, focusing on mechanical, chemical, and energy recovery methods. It situates these strategies within the context of modern practices by examining ongoing research methodologies and specific case studies related to various types of plastic waste. The global crisis of plastic waste, along with various pre‐treatment methods, is thoroughly discussed. The section on mechanical recycling details the processes applicable to different plastics, highlighting key challenges such as thermo‐mechanical issues, the use of fillers to enhance certain properties, and material degradation over time. This discussion includes polymers such as polyethylene terephthalate (PET), low‐density polyethylene (LDPE), high‐density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS). Chemical recycling is analyzed through advanced techniques like pyrolysis, catalytic pyrolysis, solvolysis, and gasification, presenting the state‐of‐the‐art in this field. Additionally, the review touches upon energy recovery and the challenges associated with it. Conclusively, the study delves into the applications of recycled plastics and outlines future challenges. Overall, this review aims to provide a thorough overview and practical guidance on the recycling of plastic waste, offering essential insights for further development in this area.
Plastic debris is unavoidably released into the ecosystems, and their physicochemical and mechanical qualities deteriorate when exposed to the environment. This, ultimately, leads to the generation of tiny fragments of plastic, which are known as nanoplastics (<1000 nm) and microplastics (<5 mm). Over the past few years, the pollution of synthetic polymers has been reported in almost all the compartments of the environment across the globe. It is regarded as a hazard to both human health and natural systems. In addition, synthetic polymers act as vectors for contaminants as they can adsorb and accumulate contaminants from seawater. The accumulation of plastic waste in the environment and its widespread presence have drawn the attention of policymakers and the public. This global issue has led to the creation of numerous remediation solutions by innovators in previous decades, either to clear up old waste or to stop plastic from entering the various matrices of the environment. This review focused on the extensive scientific research available on effective techniques for removing plastic debris to promote positive action and progress in this important area. Despite the various challenges, these techniques offer vital opportunities, from increasing awareness to enhancing environmental quality. Further, the article has been enriched by incorporating bibliometric data that illustrates the widely used methods for removing microplastics from various environmental matrices. According to the data analysis, numerous remediation techniques have been developed to date (2010 and 2024). These techniques encompass various approaches, among which the chemical‐based methods enjoy more success. This success can be attributed to the diverse advantages offered by chemical‐based methods over other remediation techniques. Much research is now focused on overcoming the disadvantages and developing more efficient and environmentally sound technologies.
Plastics are versatile materials whose production and use are growing on a global scale. However, inadequate plastic waste management and its degradation result in the release of small particles, namely microplastics (MPs) and nanoplastics (NPs), which have adverse effects in physical, biological, and socioeconomic aspects. United Nations (UN) Sustainable Development Goal (SDG) 2 is related to ending hunger, promoting food security and nutrition, and achieving agricultural sustainability. MPs and NPs may affect the productivity and quality of agricultural products and contaminate foods and beverages from other sources, increasing health risks for human consumers. A systematic bibliographic review was conducted using StArt 3.4 and Excel software to identify gaps and recent advances in selected publications from 2022 and 2023 regarding the impacts of MPs and NPs to UN SDG 2. Then, 310 selected studies that discussed consequences to the agricultural soil, foods, drinking water, and beverages were summarized. The review addressed the recent advances and results regarding sources, occurrence, mobility, and effects of MPs and NPs on soil properties, nutrient cycling, productivity, and quality of agricultural soils. We also explored sources and MPs/NPs contamination of different types of foods, drinking water, and beverages. Hence, we highlighted the presence of plastic particles along the whole food production and consumption, which calls attention to the imperativeness of public policies and changes on plastic waste management cycle. We also reinforce the need for assessing MPs and NPs contamination considering local particularities, such as the climate, most common species, and feeding habits.
Graphical Abstract
Plastics are widely used across various industries due to their flexibility, cost-effectiveness, and durability. This extensive use has resulted in significant plastic pollution, with microplastics (MPs) becoming pervasive contaminants in water bodies worldwide, adversely affecting aquatic ecosystems and human health. This review explores the surface characteristics of carbon-based adsorbents, including biochar, activated carbon, carbon nanotubes (CNTs), and graphene, and their influence on MP removal efficiency. Key surface characteristics such as the carbon content, surface area, pore size, and particle size of adsorbents influenced adsorption efficiency. Additionally, hydrophobic interaction, van der Waals forces, π–π interactions and electrostatic interaction were found to be mechanisms by which microplastics are trapped onto adsorbents. Modified biochar and activated carbon demonstrated high adsorption efficiencies, while CNTs and graphene, with their high carbon contents and well-defined mesopores, showed outstanding performance in MP removal. Although a high surface area was generally associated with better adsorption performance, modifications significantly enhanced efficiency regardless of the initial surface area. This review emphasizes the importance of understanding the relationship between surface characteristics and adsorption efficiency to develop optimized adsorbents for MP removal from wastewater. However, challenges such as the lack of standardized testing methods, variability in biochar performance, and the high cost of regenerating carbon adsorbents remain. Future research should focus on developing cost-effective production methods, optimizing biochar production, and exploring advanced modifications to broaden the application of carbon adsorbents. Integrating advanced adsorbents into existing water treatment systems could further enhance MP removal efficiency. Addressing these challenges can improve the effectiveness and scalability of carbon-based adsorbents, significantly contributing to the mitigation of microplastic pollution in wastewater.
Nanoplastics (NPs) can adversely affect living organisms. However, the uptake of NPs by plants and the physiological and molecular mechanisms underlying NP-mediated plant growth remain unclear, particularly in the presence of iron minerals and humic acid (HA). In this study, we investigated NP accumulation in rice (Oryza sativa L.) and the physiological effects of exposure to polystyrene NPs (0, 20, and 100 mg L− 1) in the presence of
iron plaque (IP) and HA. NPs were absorbed on the root surface and entered cells, and confocal laser scanning microscopy confirmed NP uptake by the roots. NP treatments decreased root superoxide dismutase (SOD) activity (28.9–44.0%) and protein contents (31.2–38.6%). IP and HA (5 and 20 mg L− 1) decreased the root protein content (20.44–58.3% and 44.2–45.2%, respectively) and increased the root lignin content (22.3–27.5% and 19.2–29.6%, respectively) under NP stress. IP inhibited the NP-induced decreasing trend of SOD activity (19.2–29.5%), while HA promoted this trend (48.7–50.3%). Transcriptomic and metabolomic analysis (Control, 100NPs, and IP-100NPs-20HA) showed that NPs inhibited arginine biosynthesis, and alanine, aspartate, and glutamate metabolism and activated phenylpropanoid biosynthesis related to lignin. The coexistence of IP and HA had positive effects on the amino acid metabolism and phenylpropanoid biosynthesis induced by NPs.
Regulation of genes and metabolites involved in nitrogen metabolism and secondary metabolism significantly altered the levels of protein and lignin in rice roots. These findings provide a scientific basis for understanding
the environmental risk of NPs under real environmental conditions.
Background: Humans cannot avoid plastic exposure due to its ubiquitous presence in the natural environment. The waste generated is poorly biodegradable and exists in the form of MPs, which can enter the human body primarily through the digestive tract, respiratory tract, or damaged skin and accumulate in various tissues by crossing biological membrane barriers. There is an increasing amount of research on the health effects of MPs. Most literature reports focus on the impact of plastics on the respiratory, digestive, reproductive, hormonal, nervous, and immune systems, as well as the metabolic effects of MPs accumulation leading to epidemics of obesity, diabetes, hypertension, and non-alcoholic fatty liver disease. MPs, as xenobiotics, undergo ADMET processes in the body, i.e., absorption, distribution, metabolism, and excretion, which are not fully understood. Of particular concern are the carcinogenic chemicals added to plastics during manufacturing or adsorbed from the environment, such as chlorinated paraffins, phthalates, phenols, and bisphenols, which can be released when absorbed by the body. The continuous increase in NMP exposure has accelerated during the SARS-CoV-2 pandemic when there was a need to use single-use plastic products in daily life. Therefore, there is an urgent need to diagnose problems related to the health effects of MP exposure and detection. Methods: We collected eligible publications mainly from PubMed published between 2017 and 2024. Results: In this review, we summarize the current knowledge on potential sources and routes of exposure, translocation pathways, identification methods, and carcinogenic potential confirmed by in vitro and in vivo studies. Additionally, we discuss the limitations of studies such as contamination during sample preparation and instrumental limitations constraints affecting imaging quality and MPs detection sensitivity. Conclusions: The assessment of MP content in samples should be performed according to the appropriate procedure and analytical technique to ensure Quality and Control (QA/QC). It was confirmed that MPs can be absorbed and accumulated in distant tissues, leading to an inflammatory response and initiation of signaling pathways responsible for malignant transformation.
Micro and nanoplastics (MNP) pollution has become an increasingly concerning environmental issue. Wastewater treatment plants represent a significant source of MNP pollution, as the treatments involved do not completely remove them. Studies on their removal from water and wastewater are of current interest. However, suitable reference materials are necessary to conduct these studies accurately and to calibrate and validate analytical techniques capable of determining their concentration in water and wastewater. This work provides new insights into developing such materials. By a simple, straightforward, and cost-effective method, we produced MNP of target commodity polymers: polyethylene (PE), polypropylene (PP), polystyrene (PS) , polyvinyl chloride (PVC) and polyethylene terephthalate (PET) in sizes ranging from 20 to 3500 nm through non-solvent precipitation. The MNP obtained were aged by exposure to UV/O3 to simulate natural plastic weathering. We assessed the dispersibility of the particles in various media and conducted a series of coagulation/flocculation tests using both aged and non-aged particles in different aqueous media. The results of these tests suggest that an 'eco-corona' was formed, which strongly influences the colloidal behavior of MNP. The MNP obtained in this work proved to be suitable for assessing MNP removal efficiency in coagulation/flocculation processes, provided that an adequate medium with a chemical composition resembling that of wastewater is used. This research not only contributes to the development of representative reference materials but also provides new insights into the colloidal behavior of MNP in wastewater, which could help optimize removal efficiencies in wastewater treatment processes.
Foliar exposure to polystyrene nanoplastics and microplastics exerted varied effects on the metabolism of lettuce ( Lactuca sativa L.).
Microplastic pollution is a problem of increasing concern in food, and while food safety issues around the world are serious, an increasing number of food safety issues related to microplastics have become the focus of people’s attention. The presence of microplastics in food is a worldwide problem, and they are present in all kinds of foods, foods of both animal and plant origin, food additives, drinks, plastic food packaging, and agricultural practices. This can cause problems for both humans and the environment. Microplastics have already been detected in human blood, heart, placenta, and breastmilk, but their effects in humans are not well understood. Studies with mammals and human cells or organoids have given perspective about the potential impact of micro(nano)plastics on human health, which affect the lungs, kidneys, heart, neurological system, and DNA. Additionally, as plastics often contain additives or other substances, the potentially harmful effects of exposure to these substances must also be carefully studied before any conclusions can be drawn. The study of microplastics is very complex as there are many factors to account for, such as differences in particle sizes, constituents, shapes, additives, contaminants, concentrations, etc. This review summarizes the more recent research on the presence of microplastic and other plastic-related chemical pollutants in food and their potential impacts on human health.
Background
Microplastics (MPs), plastic particles < 5 mm in size, are prevalent in the environment, and human exposure to them is inevitable. To assess the potential risk of MPs on human health, it is essential to consider the physicochemical properties of environmental MPs, including polymer types, size, shape, and surface chemical modifications. Notably, environmental MPs undergo degradation due to external factors such as ultraviolet (UV) rays and waves, leading to changes in their surface characteristics. However, limited knowledge exists regarding the health effects of MPs, with a specific focus on their surface degradation. This study concentrates on cytotoxic MPs with surface degradation through UV irradiation, aiming to identify the mechanisms underlying their cell toxicity.
Results
Polyethylene (PE) and surface-degraded PE achieved through UV light irradiation were employed as model MPs in this study. We explored the impact of PE and degraded PE on cell death in murine macrophage cell line RAW264.7 cells and human monocyte cell line THP-1 cells. Flow cytometric analysis revealed that degraded PE induced programmed cell death without activating caspase 3, while non-degraded PE did not trigger programmed cell death. These findings suggest that degraded PE might induce programmed cell death through mechanisms other than caspase-driven apoptosis. To understand the mechanisms of cell death, we investigated how cells responded to degraded PE-induced cellular stress. Immunofluorescence and western blotting analyses demonstrated that degraded PE induced autophagosome formation and increased p62 expression, indicating inhibited autophagy flux after exposure to degraded PE. Furthermore, degraded PE exposure led to a decrease in acidic lysosomes, indicating lysosomal dysregulation. These results imply that degraded PE induces lysosomal dysfunction, subsequently causing autophagy dysregulation and cell death.
Conclusions
This study unveils that UV-induced degradation of PE results in cell death attributed to lysosomal dysfunction. The findings presented herein provide novel insights into the effects of surface-degraded MPs on biological responses.
The widespread application of plastics and its eventual degradation to micro-sized or nano-sized plastics has led to several environmental concerns. Moreover, nanoplastics can easily cascade through the food chain accumulating in the aquatic organisms. Thus, our study focussed on investigating the hazardous impact of nano-sized plastics on aquatic species including Nitrobacter vulgaris, Scenedesmus sp, and Daphnia magna. Various concentrations of polystyrene nanoplastics ranging from 0.01 mg/L to 100 mg/L were tested against Nitrobacter vulgaris, Scenedesmus sp, and Daphnia magna. The minimum inhibitory concentration of polystyrene nanoplastics in Nitrobacter vulgaris was found to be 25 mg/L, and in Daphnia magna, the median lethal concentration 50 was observed to be 64.02 mg/L. Exposure of Scenedesmus sp with increasing nanoplastic concentrations showed a significant decrease in total protein (p < 0.001), and chlorophyll content (p < 0.01), whereas the lipid peroxidation increased (p < 0.001) significantly. Similarly, Nitrobacter vulgaris and Daphnia magna showed a significant decrease in catalase activity (p < 0.001) and an increase in lipid peroxidation levels (p < 0.01). Concomitant with lipid peroxidation results, decreased superoxide dismutase levels (p < 0.01) and protein concentrations (p < 0.01) were observed in Daphnia magna. Besides, the increasing concentration of polystyrene nanoplastics displayed an elevated mortality rate in Scenedesmus sp (p < 0.001) and Nitrobacter vulgaris (p < 0.01). Further, scanning electron microscopy analysis substantiated the morphological alterations in Nitrobacter vulgaris and Scenedesmus sp on exposure to polystyrene nanoplastics.
Graphical Abstract
Plastic in the global oceans fulfills two of the three conditions for pollution to pose a planetary boundary threat because it is causing planetary-scale exposure that is not readily reversible. Plastic is a planetary boundary threat if it is having a currently unrecognized disruptive effect on a vital Earth system process. Discovering possible unknown effects is likely to be aided by achieving a fuller understanding of the environmental fate of plastic. Weathering of plastic generates microplastic, releases chemical additives, and likely also produces nanoplastic and chemical fragments cleaved from the polymer backbone. However, weathering of plastic in the marine environment is not well understood in terms of time scales for fragmentation and degradation, the evolution of particle morphology and properties, and hazards of the chemical mixture liberated by weathering. Biofilms that form and grow on plastic affect weathering, vertical transport, toxicity, and uptake of plastic by marine organisms and have been underinvestigated. Laboratory studies, field monitoring, and models of the impact of weathering on plastic debris are needed to reduce uncertainty in hazard and risk assessments for known and suspected adverse effects. However, scientists and decision makers must also recognize that plastic in the oceans may have unanticipated effects about which we are currently ignorant. Possible impacts that are currently unknown can be confronted by vigilant monitoring of plastic in the oceans and discovery-oriented research related to the possible effects of weathering plastic.
The release of plastics into the environment has been identified as an important issue for some time. Recent publications have suggested that the degradation of plastic materials will result in the release of nano-sized plastic particles to the environment. Nanoparticle tracking analysis was applied to characterise the formation of nanoplastics during the degradation of a polystyrene (PS) disposable coffee cup lid. The results clearly show an increase in the formation of nanoplastics over time. After 56 days' exposure the concentration of nanoplastics in the PS sample was 1.26 × 108 particles/ml (average particles size 224 nm) compared to 0.41 × 108 particles/ml in the control.
There have been numerous anthropogenic-driven changes to our planet in the last half-century. One of the most evident changes is the ubiquity and abundance of litter in the marine environment. The EU Marine Strategy Framework Directive (MSFD, 2008/56/EC) establishes a framework within which EU Member States shall take action to achieve or maintain good environmental status (GES) of their marine waters by 2020. GES is based on 11 qualitative descriptors as listed in Annex I of the MSFD. Descriptor 10 (D 10) concerns marine litter. As a follow-up to the related Commission Decision on criteria and methodological standards (2010/477/EU) in which 56 indicators for the achievement of GES are proposed, the EC Directorate-General for the Environment, on the request of the European Marine Directors, established a Technical Subgroup on Marine Litter (TSG ML) under the Working Group on GES. The role of TSG ML is to support Member States through providing scientific and technical background for the implementation of MSFD requirements with regard to D 10. Started in 2011, TSG ML provides technical recommendations for the implementation of the MSFD requirements for marine litter. It summarizes the available information on monitoring approaches and considers how GES and environmental targets could be defined with the aim of preventing further inputs of litter to, and reducing its total amount in, the marine environment. It also identifies research needs, priorities and strategies in support of the implementation of D 10. The work of TSG ML also focuses on the specification of monitoring methods through the development of monitoring protocols for litter in the different marine compartments, and for microplastics and litter in biota. Further consideration is being given to monitoring strategies in general and associated costs. Other priorities include the identification of sources of marine litter and a better understanding of the harm caused by marine litter.
Significance
High concentrations of floating plastic debris have been reported in remote areas of the ocean, increasing concern about the accumulation of plastic litter on the ocean surface. Since the introduction of plastic materials in the 1950s, the global production of plastic has increased rapidly and will continue in the coming decades. However, the abundance and the distribution of plastic debris in the open ocean are still unknown, despite evidence of affects on organisms ranging from small invertebrates to whales. In this work, we synthetize data collected across the world to provide a global map and a first-order approximation of the magnitude of the plastic pollution in surface waters of the open ocean.
Unique forms of manufactured nanomaterials, nanoparticles, and their suspensions are rapidly being created by manipulating properties such as shape, size, structure, and chemical composition and through incorporation of surface coatings. Although these properties make nanomaterial development interesting for new applications, they also challenge the ability of colloid science to understand nanoparticle aggregation in the environment and the subsequent effects on nanomaterial transport and reactivity. This review briefly covers aggregation theory focusing on Derjaguin-Landau-Verwey-Overbeak (DLVO)-based models most commonly used to describe the thermodynamic interactions between two particles in a suspension. A discussion of the challenges to DLVO posed by the properties of nanomaterials follows, along with examples from the literature. Examples from the literature highlighting the importance ofaggregation effects on transport and reactivity and risk of nanoparticles in the environment are discussed.
Plastics can be found in all ecosystems across the globe. This type of environmental pollution is important, even if its impact is not fully understood. The presence of small plastic particles at the micro- and nanoscales is of growing concern, but nanoplastic has not yet been observed in natural samples. In this study, we examined four size fractions (meso-, large micro-, small micro-, and nanoplastics) of debris collected in the North Atlantic subtropical gyre. To obtain the nanoplastic portion, we isolated the colloidal fraction of seawater. After ultrafiltration, the occurrence of nanoscale particles was demonstrated using dynamic light scattering experiments. The chemical fingerprint of the colloids was obtained by pyrolysis coupled with gas chromatography–mass spectrometry. We demonstrated that the signal was anthropogenic and attributed to a combination of plastics. The polymer composition varied among the size classes. At the micro- and nanoscales, polyvinyl chloride, polyethylene terephthalate, polystyrene and polyethylene were observed. We also observed changes in the pyrolytic signals of polyethylene with decreasing debris size, which could be related to the structural modification of this plastic as a consequence of weathering.
Plastic pollution has been globally recognized as a critical issue for marine ecosystems and nanoplastics constitute one of the last unexplored areas to understand the magnitude of this threat. However, current difficulties in sampling and identifying nano-sized debris make hard to assess their occurrence in marine environment. Polystyrene nanoparticles (PS NPs) are largely used as nanoplastics in ecotoxicological studies and although acute exposures have been already investigated, long-term toxicity on marine organisms is unknown. Our study aims at evaluating the effects of 40 nm PS anionic carboxylated (PS-COOH) and 50 nm cationic amino-modified (PS-NH2) NPs in two planktonic species, the green microalga Dunaliella tertiolecta and the brine shrimp Artemia franciscana, respectively prey and predator. PS NP behaviour in exposure media was determined through DLS, while their toxicity to microalgae and brine shrimps evaluated through 72 h growth inhibition test and 14 d long-term toxicity test respectively. Moreover, the expression of target genes (i.e. clap and cstb), having a role in brine shrimp larval growth and molting, was measured in 48 h brine shrimp larvae. A different behaviour of the two PS NPs in exposure media as well as diverse toxicity to the two planktonic species was observed. PS-COOH formed micro-scale aggregates (Z-Average > 1 μm) and did not affect the growth of microalgae up to 50 μg/ml or that of brine shrimps up to 10 μg/ml. However, these negatively charged NPs were adsorbed on microalgae and accumulated (and excreted) in brine shrimps, suggesting a potential trophic transfer from prey to predator. On the opposite, PS-NH2-formed nano-scale aggregates (Z-Average < 200 nm), caused inhibition of algal growth (EC50 = 12.97 μg/ml) and mortality in brine shrimps at 14 d (LC50 = 0.83 μg/ml). Moreover, 1 μg/ml PS-NH2 significantly induced clap and cstb genes, explaining the physiological alterations (e.g. increase in molting) previously observed in 48 h larvae, but also suggesting an apoptotic pathway triggered by cathepsin L-like protease in brine shrimps upon PS-NH2 exposure. These findings provide a first insight into long-term toxicity of nanoplastics to marine plankton, underlining the role of the surface chemistry in determining the behaviour and effects of PS NPs, in terms of adsorption, growth inhibition, accumulation, gene modulation and mortality. The use of long-term end-point has been identified as valuable tool for assessing the impact of nanoplastics on marine planktonic species, being more predictable of real exposure scenarios for risk assessment purposes.
Evidence is increasing that micro- and nanoplastic particles can have adverse effects on aquatic organisms. Exposure studies have so far mainly been qualitative since quantitative measurements of particle ingestion are analytically challenging. The aim of this study was therefore to use a quantitative approach for determining ingestion and egestion of micro- and nanoplastics in Daphnia magna and to analyze the influence of particle size, exposure duration and the presence of food. One week old animals were exposed to 2 μm and 100 nm fluorescent polystyrene beads (1 mg/l) for 24 h, followed by a 24 h egestion period in clean medium. During both phases body burdens of particles were determined by measuring the fluorescence intensity in dissolved tissues. Ingestion and egestion were investigated in the absence and presence of food (6.7·10⁵ cells of Raphidocelis subcapitata per ml). Furthermore, feeding rates of daphnids in response to particle exposure were measured as well as effects on reproduction during a 21 days exposure (at 1 mg/l, 0.5 mg/l and 0.1 mg/l) to investigate potential impairments of physiology. Both particle sizes were readily ingested, but the ingested mass of particles was five times higher for the 2 μm particles than for the 100 nm particles. Complete egestion did not occur within 24 h but generally higher amounts of the 2 μm particles were egested. Animal body burdens of particles were strongly reduced in the presence of food. Daphnid feeding rates decreased by 21% in the presence of 100 nm particles, but no effect on reproduction was found despite high body burdens of particles at the end of 21 days exposure. The lower egestion and decreased feeding rates, caused by the 100 nm particles, could indicate that particles in the nanometer size range are potentially more hazardous to D. magna compared to larger particle sizes.
This study investigated the direct and indirect toxic effects of microplastics and nanoplastics toward zebrafish (Danio rerio) larvae locomotor activity. Results showed that microplastics alone exhibited no significant effects except for the upregulated zfrho visual gene expression; whereas nanoplastics inhibited the larval locomotion by 22% during the last darkness period, and significantly reduced larvae body length by 6%, inhibited the acetylcholinesterase activity by 40%, and upregulated gfap, α1-tubulin, zfrho and zfblue gene expression significantly. When co-exposed with 2 μg/L 17 α-ethynylestradiol (EE2), microplastics led to alleviation on EE2's inhibition effect on locomotion, which was probably due to the decreased freely dissolved EE2 concentration. However, though nanoplastics showed stronger adsorption ability for EE2, the hypoactivity phenomenon still existed in the nanoplastics co-exposure group. Moreover, when co-exposed with a higher concentration of EE2 (20 μg/L), both plastics showed an enhanced effect on the hypoactivity. Principal component analysis was performed to reduce data dimensions and four principal components were reconstituted in terms of oxidative stress, body length, nervous and visual system related genes explaining 84% of total variance. Furthermore, oxidative damage and body length reduction were evaluated to be main reasons for the hypoactivity. Therefore, nanoplastics alone suppressed zebrafish larvae locomotor activity and both plastic particles can change the larvae swimming behavior when co-exposed with EE2. This study provides new insights into plastic particles' effects on zebrafish larvae, improving the understanding of their environmental risks to the aquatic environment.
Microplastics (MPs) have been identified as contaminants of emerging concern in aquatic environments and research into their behavior and fate has been sharply increasing in recent years. Nevertheless, significant gaps remain in our understanding of several crucial aspects of MP exposure and risk assessment, including the quantification of emissions, dominant fate processes, types of analytical tools required for characterization and monitoring, and adequate laboratory protocols for analysis and hazard testing. This Feature aims at identifying transferrable knowledge and experience from engineered nanoparticle (ENP) exposure assessment. This is achieved by comparing ENP and MPs based on their similarities as particulate contaminants, while critically discussing specific differences. We also highlight the most pressing research priorities to support an efficient development of tools and methods for MPs environmental risk assessment.
This chapter concerns the structure, chemical composition, properties and degradation of plastic materials in the environment. Detailed diagrams of the chemical structure of the most common plastics are provided as well as background information. Furthermore, many properties of plastics are discussed, such as the glass transition temperature, the limiting oxygen index and their resistance to ultraviolet light. Additionally, details of the minimum and maximum operating temperatures of the most common materials are indicated. In terms of degradation, the latest information regarding biotic degradation is discussed as well as the provision of a list of known plastic-degrading organisms. Furthermore, the various forms of abiotic degradative effects on plastic materials are covered in detail, as well as the effects of additives in modifying and improving the properties of plastic materials.
To investigate processes possibly underlying accumulation and ecological effects of plastic nano-particles we have characterized their interaction with the cell wall of green algae. More specifically, we have investigated the influence of particle surface functionality and water hardness (Ca²⁺ concentration) on particle adsorption to algae cell walls. Polystyrene nanoparticles with different functional groups (non-functionalized, −COOH and −NH2) as well as coated (starch and PEG) gold nanoparticles were applied in these studies. Depletion measurements and atomic force microscopy (AFM) showed that adsorption of neutral and positively charged plastic nanoparticles onto the cell wall of P. subcapitata was stronger than that of negatively charged plastic particles. Results indicated that binding affinity is a function of both inter-particle and particle-cell wall interactions which are in turn influenced by the medium hardness and particle concentration. Physicochemical modeling using DLVO theory was used to interpret the experimental data, using also values for interfacial surface free energies. Our study shows that material properties and medium conditions play a crucial role in the rate and state of nanoparticle bio-adsorption for green algae. The results show that the toxicity of nanoparticles can be better described and assessed by using appropriate dose metrics including material properties, complexation/agglomeration behavior and cellular attachment and adsorption. The applied methodology provides an efficient and feasible approach for evaluating potential accumulation and hazardous effects of nanoparticles to algae caused by particle interactions with the algae cell walls.
There has been a considerable increase on research of the ecological consequences of microplastics released into the environment, but only a handful of works have focused on the nano-sized particles of polymer-based materials. Though their presence has been difficult to adequately ascertain, due to the inherent technical difficulties for isolating and quantifying them, there is an overall consensus that these are not only present in the environment – either directly released or as the result of weathering of larger fragments – but that they also pose a significant threat to the environment and human health, as well. The reduced size of these particulates (< 1 μm) makes them susceptible of ingestion by organisms that are at the base of the food-chain. Moreover, the characteristic high surface area-to-volume ratio of nanoparticles may add to their potential hazardous effects, as other contaminants, such as persistent organic pollutants, could be adsorbed and undergo bioaccumulation and bioamplification phenomena.
The global estimation of microplastic afloat in the ocean is only approximately 1% of global plastic inputs. This reflects fundamental knowledge gaps in the transformation, fragmentation and fates of microplastics in the ocean. In order to better understand microplastic fragmentation we proceeded to a thorough physicochemical characterization of samples collected from the North Artlantic sub-tropical gyre during the sea campaign Expedition 7th Continent in May 2014. The results were confronted with a mathematical approach. The introduction of mass distribution in opposition to the size distribution commonly proposed in this area clarify the fragmentation pattern. The mathematical analysis of the mass distribution points out a lack of mass for debris lighter than 1 mg, which corresponds to a size of 2 mm. Characterization by means of microscopy, microtomography and infrared microscopy gives a better understanding of the behavior of microplastic at sea. Flat pieces of debris (5-2 mm), referred to as parallelepipeds, float with one face preferentially exposed to the sun. This face is more photodegraded and biofilm also develops preferentially on it. Smaller debris, with a cubic shape (below 2 mm), seems to roll at sea. All faces are evenly photodegraded and they are less colonized. The breakpoint in the mathematical model and the experimental observation around 2 to 1 mm leads to the conclusion that there is a discontinuity in the rate of fragmentation: we hypothesized that the smaller microplastics, the cubic ones mostly, are fragmented much faster than the parallelepipeds.
In this work, we present for the first time undeniable evidence of nano-plastic occurrence due to solar light degradation of marine micro-plastics under controlled and environmentally representative conditions. As observed during our recent expedition (Expedition 7th Continent), plastic pollution will be one of the most challenging ecological threats for the next generation. Up to now, all studies have focused on the environmental and the economic impact of millimeter scale plastics. These plastics can be visualized, collected and studied. We are not aware of any studies reporting the possibilities of nano-plastics in marine water. Here, we developed for the first time a new solar reactor equipped with a nanoparticle detector to investigate the possibility of the formation of nano-plastics from millimeter scale plastics. With this system, correlated with electronic microscopy observations, we identified for the first time the presence of plastics at the nano-scale in water due to UV degradation. Based on our observations large fractal nano-plastic particles (i.e., >100 nm) are produced by UV light after the initial formation of the smallest nano-plastic particles (i.e., <100 nm). These unprecedented results show the new and unprecedented potential hazards of plastic waste at the nanoscale, which had not been taken into account previously.
Plastic debris is a prolific contaminant effecting freshwater and marine ecosystems across the globe. Of growing environmental concern are 'microplastics' and 'nanoplastics', encompassing tiny particles of plastic derived from manufacturing and macroplastic fragmentation. Pelagic zooplankton are susceptible to consuming microplastics, however the threat posed to larvae of commercially important bivalves is currently unknown. We exposed Pacific oyster (Crassostrea gigas) larvae (3-24 d.p.f.) to polystyrene particles spanning 70 nm-20 µm in size, including plastics with differing surface properties, and tested the impact of microplastics on larval feeding and growth. The frequency and magnitude of plastic ingestion over 24 hours varied by larval age and size of polystyrene particle (ANOVA, P<0.01), and surface properties of the plastic, with aminated particles ingested and retained more frequently (ANOVA, P<0.01). A strong, significant correlation between propensity for plastic consumption and plastic load per organism was identified (Spearmans, r=0.95, P<0.01). Exposure to 1 and 10 µm PS for up to 8 days had no significant effect on C. gigas feeding or growth at <100 microplastics mL-1. In conclusion, whilst micro- and nanoplastics were readily ingested by oyster larvae, exposure to plastic concentrations exceeding those observed in the marine environment resulted in no measurable effects on the development or feeding capacity of the larvae over the duration of the study.
High concentrations of plastic debris have been observed in the oceans. Much of the recent concern has focussed on microplastics in the marine environment. Recent studies of the size distribution of the plastic debris suggested that continued fragmenting of microplastics into nano-sized particles may occur. In this review we assess the current literature on the occurrence of environmentally released micro- and nanoplastics in the human food production chain and their potential health impact. The currently used analytical techniques introduce a great bias in the knowledge, since they are only able to detect plastic particles well above the nano-range. We discuss the potential use of the very sensitive analytical techniques that have been developed for the detection and quantification of engineered nanoparticles. We recognize three possible toxic effects of plastic particles: firstly due to the plastic particles themselves, secondly to the release of persistent organic pollutant adsorbed to the plastics, and thirdly to the leaching of additives of the plastics. The limited data on microplastics in foods do not predict adverse effect of these pollutants or additives. Potential toxic effects of microplastic particles will be confined to the gut. The potential human toxicity of nanoplastics is poorly studied. Based on our experiences in nanotoxicology we prioritized future research questions.
Plastic debris are resistant to degradation, and therefore tend to accumulate in marine environment. Nevertheless recent estimations of plastic concentrations at the surface of the ocean were lower than expected leading the communities to seek new sinks. Among the different processes suggested we chose to focus on the transport of microplastics from the surface to deeper layers of the ocean via phytoplankton aggregates that constitute most of the sinking flux. Interactions between microplastics and aggregates were studied by building a new device: the flow-through roller tank that mimics the behaviour of laboratory made aggregates sinking through a dense layer of microplastics. Three types of aggregates formed from two different algae species (the diatom Chaetoceros neogracile, the cryptophyte Rhodomonas salina and a mix) were used as model. With their frustule made of biogenic silica which is denser than the organic matter, diatom aggregates sunk faster than R. salina aggregates. Diatom aggregates were on average bigger and stickier while aggregates from R. salina were smaller and more fragile. With higher concentrations measured in R. salina aggregates, all model-aggregates incorporated and concentrated microplastics, substantially increasing the microplastic sinking rates from tenths to hundreds of metres per day. Our results clearly show that marine aggregates can be an efficient sink for microplastics by influencing their vertical distribution in the water column. Furthermore, despite the high plastic concentrations tested, our study opens new questions regarding the impact of plastics on sedimentation fluxes in oceans. As an effect of microplastic incorporation, the sinking rates of diatom aggregates strongly decreased meanwhile sinking rates of cryptophyte aggregates increased.
Microscopic plastic debris, termed "microplastics", are of increasing environmental concern. Recent studies have demonstrated that a range of zooplankton, including copepods, can ingest microplastics. Copepods are a globally abundant class of zooplankton that form a key trophic link between primary producers and higher trophic marine organisms. Here we demonstrate that ingestion of microplastics can significantly alter the feeding capacity of the pelagic copepod Calanus helgolandicus. Exposed to 20 μm polystyrene beads (75 microplastics mL(-1)) and cultured algae ([250 μg C L(-1)) for 24 h, C. helgolandicus ingested 11% fewer algal cells (P = 0.33) and 40% less carbon biomass (P < 0.01). There was a net downward shift in the mean size of algal prey consumed (P < 0.001), with a 3.6 fold increase in ingestion rate for the smallest size class of algal prey (11.6-12.6 μm), suggestive of postcapture or postingestion rejection. Prolonged exposure to polystyrene microplastics significantly decreased reproductive output, but there were no significant differences in egg production rates, respiration or survival. We constructed a conceptual energetic (carbon) budget showing that microplastic-exposed copepods suffer energetic depletion over time. We conclude that microplastics impede feeding in copepods, which over time could lead to sustained reductions in ingested carbon biomass.
Dynamic light scattering has evolved as a fast, convenient tool for particle size analysis of non-interacting spherical colloids. In this instructional review, we discuss the basic principle, data analysis and important precautions to be taken while analysing colloids using DLS. The effect of particle interaction, polydispersity, anisotropy, light absorption etc on measured diffusion coefficient is discussed. New developments in this area such as diffusing wave spectroscopy, particle tracking analysis, microrheological studies using DLS etc are discussed in a manner that can be understood by a beginner.
With the accelerating introduction of engineered nanomaterials into commercial products and their potential use in water-treatment processes, it is inevitable that these materials will ultimately reside at some level in our recreational and drinking waters, thereby creating a critical need to detect and to quantify them in those media.Much is known about the diversity of engineered nanoparticles (ENPs) in the environment but almost nothing about their characterization and detection in the natural aquatic environment.There is no conventional treatment that can absolutely protect the consumer from exposure to ENPs either through recreational use or consumption of drinking waters. The question is whether this exposure poses a significant public health risk.Unfortunately, we are far from having methods to obtain data on occurrence levels, fate, and transport of ENPs in aquatic systems. Before a sound analytical approach can be developed, we need a fuller understanding of the nanomaterial domain which requires an evaluation of the matrix of source materials, their transformation in the natural aquatic environment, and their physical/chemical behavior that is specific to the water medium.We review characterization techniques that are used for identifying different types of ENP, and then, by extrapolation from isolation techniques appropriate for extracting ENPs from water, suggest approaches to analyzing them in a variety of waters.
Nanoparticles are important in natural environments due to their size, tunable properties and accessible surfaces and our control over these properties can be exploited to create or add value to a variety of technologies. Many consumer products that incorporate nanoparticles, such as sunscreens and clothing, are already in the marketplace, and the industry is growing fast. This book highlights also the many valuable environmental technologies that can come from the applications of unique nanomaterial properties. As this nascent technology area matures, the debate about the whether the unknown risks of nanomaterial use balances its established benefits will only intensify.
In this work we study the kinetics of coagulation of monodisperse spherical colloids in aqueous suspension at the early stage of coagulation. We have performed the measurements on a multiangle static and dynamic light scattering instrument using a fiber-optics-based detection system which permits simultaneous time-resolved measurements at different angles. The absolute coagulation rate constants are determined from the change of the scattering light intensity as well as from the increase of the hydrodynamic radius at different angles. The combined evaluation of static and dynamic light scattering results permits the determination of coagulation rate constants without the explicit use of light scattering form factors for the aggregates. For different electrolytes fast coagulation rate constants were estimated. Stability curves were measured as a function of ionic strength using different particle concentrations.
This review discusses the mechanisms of generation and potential impacts of microplastics in the ocean environment. Weathering degradation of plastics on the beaches results in their surface embrittlement and microcracking, yielding microparticles that are carried into water by wind or wave action. Unlike inorganic fines present in sea water, microplastics concentrate persistent organic pollutants (POPs) by partition. The relevant distribution coefficients for common POPs are several orders of magnitude in favour of the plastic medium. Consequently, the microparticles laden with high levels of POPs can be ingested by marine biota. Bioavailability and the efficiency of transfer of the ingested POPs across trophic levels are not known and the potential damage posed by these to the marine ecosystem has yet to be quantified and modelled. Given the increasing levels of plastic pollution of the oceans it is important to better understand the impact of microplastics in the ocean food web.
Nanotechnology has widespread application in agricultural, environmental and industrial sectors ranging from fabrication of molecular assemblies to microbial array chips. Despite the booming application of nanotechnology, there have been serious implications which are coming into light in the recent years within different environmental compartments, namely air, water and soil and its likely impact on the human health. Health and environmental effects of common metals and materials are well-known, however, when the metals and materials take the form of nanoparticles--consequential hazards based on shape and size are yet to be explored. The nanoparticles released from different nanomaterials used in our household and industrial commodities find their way through waste disposal routes into the wastewater treatment facilities and end up in wastewater sludge. Further escape of these nanoparticles into the effluent will contaminate the aquatic and soil environment. Hence, an understanding of the presence, behavior and impact of these nanoparticles in wastewater and wastewater sludge is necessary and timely. Despite the lack of sufficient literature, the present review attempts to link various compartmentalization aspects of the nanoparticles, their physical properties and toxicity in wastewater and wastewater sludge through simile drawn from other environmental streams.
The industrial scale production and wide variety of applications of manufactured nanoparticles (NPs) and their possible release in considerable amounts into the natural aquatic environment have produced an increasing concern among the nanotechnology and environmental science community. In order to address this issue, it is important to understand NP chemistry, preparation, reactivity and possible mechanisms involved in their interaction with the naturally occurring aquatic components, particularly natural colloids and NPs present in the aquatic systems. In this review, an overview of the chemistry of both manufactured and natural aquatic NPs is outlined. This review discusses the physico-chemical aspects of both type of NPs as an essential point to assess possible routes involved in manufactured NP fate in the natural aquatic environment and their toxicity. Key advances related to the characterisation of the manufactured NPs and natural colloids.
Nanoplastic in the North atlantic subtropical gyre
- A Ter Halle
- L Jeannau
- M Martignac
- E Jard E
- B Pedrono
- L Brach
- J Gigault
Ter Halle, A., Jeannau, L., Martignac, M., Jard e, E., Pedrono, B., Brach, L., Gigault, J.,
2017. Nanoplastic in the North atlantic subtropical gyre. Env. Sci Technol. 51
(23), 13689e13697.