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Fate of Nanoplastics in Marine Larvae: A Case Study Using Barnacles, Amphibalanus amphitrite
Abstract
The exposure of nanoplastics was investigated by observing their interaction with Amphibalanus amphitrite (commonly known as acorn barnacles). Poly(methyl methacrylate) (PMMA) and fluorescent perylene tetraester (PTE) dye were used to prepare highly fluorescent nanoplastic particles. At concentrations of 25 ppm, the PMMA particles showed no detrimental impact on barnacle larvae and their microalgae feed, Tetraselmis suecica and Chaetoceros muelleri. PMMA nanoplastics were ingested and translocated inside the body of the barnacle nauplii within the first 3 hours of incubation. The fluorescent PMMA particles inside the transparent nauplius were tracked using confocal fluorescence microscopy. Subsequently, the nanoplastics were fed to the barnacles under two conditions – acute and chronic exposure. The results from acute exposure show that nanoplastics persist in the body throughout stages of growth and development – from nauplius to cyprid and juvenile barnacle. Some egestion of nanoplastics was observed through moulting and faecal excrement. In comparison, chronic exposure demonstrates bioaccumulation of the nanoplastics even at low concentrations of the plastics. The impacts of our study using PMMA nanoparticles exceeds current knowledge, where most studies stop at uptake and ingestion. Here we demonstrate that uptake of nanoparticles during planktonic larval stages may persist to the adult stages, indicating the potential for the long-term impacts of nanoplastics on sessile invertebrate communities.
... The observed toxic effects of polymer micro-and nanoparticles depend on the concentration, exposure time, chemical structure, additives and the choice of animal models (Guo et al., 2023, Tang et al., 2023, Yip et al., 2022, Bhargava et al., 2018. The polyvinyl chloride (PVC) polymer contains toxic chemical additives (e.g., phthalates, lead, cadmium, and organotin compounds) which leach into the environment and cause toxicity in aquatic organisms (Lithner et al., 2012;Wang et al., 2020). ...
... A few studies on the acute toxicity of NP-PVC (98 nm) with 99 % mortality have been reported in Amphibalanus amphitrite (barnacle nauplii) model as compared to a similar size of NP-PS and NP-PMMA for 24 h (Yu et al., 2021, Yip et al., 2022. In contrast, NP-PMMA (185 nm) showed no toxicity in A. amphitrite when exposed to 25 mg/L for 24 h (Bhargava et al., 2018). However, little is known about the toxicity of NP-PVC and NP-PMMA on other marine organisms. ...
... Finally, the NP solution was filtered using a cotton plug into a 500 mL volumetric flask and adjusted to 500 mL with ultrapure water. In the present study, the hydrophobic PTE dye was encapsulated inside the PVC and PMMA matrixes with little or no leaching of the dye into the aqueous environment (Bhargava et al., 2018;Yip et al., 2022). ...
Plastic products have become an integral part of our life. A widespread usage, high stability, uncontrolled disposal and slow degradation of plastics in the environment led to the generation and accumulation of nanoparticles of polymers (NPs) in the marine environment. However, little is known about the aggregation, consumption and distribution of NPs from common polymers such as polyvinyl chloride (NP-PVC) and polymethyl methacrylate (NP-PMMA), inside marine animal physiologies. In the current study, two types of polymers (PVC and PMMA) × four exposure concentrations (1, 5, 15 and 25 mg/L) × four times (4, 8, 12 and 24 h) exposure studies were conducted to understand the consumption and distribution of luminescent NP-PVC (98.6 ± 17.6 nm) and NP-PMMA (111.9 ± 37.1 nm) in R. philippinarum. Under laboratory conditions, NP-PVC showed a higher aggregation rate than NP-PMMA in seawater within a period of 24 h. Aggregations of NPs increased with an increase in initial NP concentrations, leading to significant settling of nanoparticles within 24 h exposure. Such aggregation and settling of particles enhanced the consumption of NPs by bottom-feeding R. philippinarum at all exposure concentrations during 4 h exposure. More interestingly, NP-PVC and NP-PMMA were seen in high amounts in both liver and gills (22.6 % - 29.1 %) of the clams. Furthermore, NP-PVC was detected in most organs of R. philippinarum as compared to NP-PMMA. This study demonstrates that different polymers distribute and accumulate differently in the same biological model under laboratory exposure conditions based on their chemical nature.
... 12−14 The toxicity and retention time of micro-and nanoplastic particles in living organisms have been shown to increase with a decrease in particle size. 15−18 Ingested micro-and nanoplastics have been shown to translocate by absorption through the lumen of the digestive tract of various animal models in both invertebrates 14,19 and vertebrates. 13,20,21 While translocation mechanisms of micro-and nanoplastics are not explained in detail for most studies, there is evidence to show that plastic nanoparticles are small enough to translocate from the digestive tract to other tissues 22 and reach the internal organs such as the liver, 20,21 brain, 23 hemolymph, 24 and gonads. ...
... PMMA was selected as the nanoplastic analogue. We reported that PMMA nanoparticle exposure is nontoxic at up to 25 mg/L, 14,33 and optically transparent monodispersed PMMA nanoparticles can be prepared via precipitation in water. 34 The hydrophobic blue fluorophore, perylene, is compatible with PMMA encapsulation and showed no leaching in water or seawater. ...
... We reported earlier that A. amphitrite nauplii ingest and retain PMMA nanoparticles in their body but develop into the juvenile stage without observable deformations or toxicity. 14 The effects of PMMA nanoparticle exposure have not been reported widely as most nanoplastic literature has focused extensively on PS as a model nanoplastic. 31 In fact, PMMA nanoparticles did not have adverse interactions with the microalgae Tetraselmis suecica and Chaetoceros muelleri 14 used as the microalgal feed for sustaining A. amphitrite adults in this study. ...
... This may be due to the small size of nanoplastics, which increases their ability to cross biological membranes within organisms and/or to become entrapped (Rossi et al., 2013). Bhargava et al. (2018) exposed larval barnacles to nano PMMA and found that even following a single acute exposure over 3 h, the nanoplastics remained in the body of the barnacles after 7 days; they also observed accumulation of PMMA from chronic exposure (Bhargava et al., 2018). This capability to accumulate within an organism's tissue enhances the possibility for trophic transfer and biomagnification. ...
... This may be due to the small size of nanoplastics, which increases their ability to cross biological membranes within organisms and/or to become entrapped (Rossi et al., 2013). Bhargava et al. (2018) exposed larval barnacles to nano PMMA and found that even following a single acute exposure over 3 h, the nanoplastics remained in the body of the barnacles after 7 days; they also observed accumulation of PMMA from chronic exposure (Bhargava et al., 2018). This capability to accumulate within an organism's tissue enhances the possibility for trophic transfer and biomagnification. ...
Reports of plastics, at higher levels than previously thought, in the water that we drink and the air that we breathe, are generating considerable interest and concern. Plastics have been recorded in almost every environment in the world with estimates on the order of trillions of microplastic pieces. Yet, this may very well be an underestimate of plastic pollution as a whole. Once microplastics (<5 mm) break down in the environment, they nominally enter the nanoscale (<1,000 nm), where they cannot be seen by the naked eye or even with the use of a typical laboratory microscope. Thus far, research has focused on plastics in the macro- (>25 mm) and micro-size ranges, which are easier to detect and identify, leaving large knowledge gaps in our understanding of nanoplastic debris. Our ability to ask and answer questions relating to the transport, fate, and potential toxicity of these particles is disadvantaged by the detection and identification limits of current technology. Furthermore, laboratory exposures have been substantially constrained to the study of commercially available nanoplastics; i.e., polystyrene spheres, which do not adequately reflect the composition of environmental plastic debris. While a great deal of plastic-focused research has been published in recent years, the pattern of the work does not answer a number of key factors vital to calculating risk that takes into account the smallest plastic particles; namely, sources, fate and transport, exposure measures, toxicity and effects. These data are critical to inform regulatory decision making and to implement adaptive management strategies that mitigate risk to human health and the environment. This paper reviews the current state-of-the-science on nanoplastic research, highlighting areas where data are needed to establish robust risk assessments that take into account plastics pollution. Where nanoplastic-specific data are not available, suggested substitutions are indicated.
... PS, PS-COOH, PS-NH 2 and PMMA, ranging from 40 to 100 nm, are NPs polymers that have been studied in crustaceans (Bergami et al., , 2020Gambardella et al., 2017;Bhargava et al., 2018;Sendra et al., 2020; Table 2). As seen in other organisms, PS-COOH, although ingested, does not have adverse effects in crustaceans, whereas PS-NH 2 is highly toxic . ...
... This suggests that NPs surface charge is an important factor determining the particles toxicity. On acute toxicity responses, (24, 48 and 72 h) NPs exposure led to an inhibitory effect on growth, development and mobility, and an increase accumulation of NPs as well as the mortality of larvae (Lee et al., 2013;Bergami et al., 2017Bergami et al., , 2020Gambardella et al., 2017;Bhargava et al., 2018;Sendra et al., 2020). The Antarctic krill, Euphasia superba, is a keystone species as they play an essential role in the Antarctic food chains and carbon cycling, and recently, after an exposure to PS-NH 2 (50 nm; 2.5 µg/L; 48 h), a reduction in swimming activity and increased moulting was observed (Bergami et al., 2020). ...
Plastic contamination in the ocean has recently received a lot of attention. Plastic production has been growing and its use spread to many sectors. More than 80% of plastic enters the ocean from land-based sources, with the remaining having ocean-based sources. Once in the ocean, plastic undergoes fragmentation and degradation that lead to the formation of microplastics (MPs) and nanoplastics (NPs), and their dimensions are becoming an environmental concern. Thus, this chapter provides an overview of the effects of MPs and NPs on marine organisms, from bacteria to fish. Plastic affects marine organisms from molecular to population levels but some knowledge gaps exist regarding the biogeochemical cycle of plastic, how it behaves and is distributed in the aquatic-sediment compartment and in deep-sea. Moreover, more attention is necessary concerning NPs ecotoxicological effects already detected and because not all polymer types and size effects have been investigated. In addition, risk assessment of plastic particles is needed to characterize their risks and for data to be comparable.
... Macroplastics are defined as plastics over 20 mm in size, while plastic particles measuring between 5 mm and 20 mm in size are defined as mesoplastics. MPs are defined as plastic particles less than 5 mm in size (Liu et al., 2018), can further be categorised into nanoplastics, with diameters ranging from 1 nm to 100 nm or 1000 nm, depending on the classification (Bhargava et al., 2018;Magrì et al., 2018). Additionally, primary plastics are deliberately added to cosmetic and personal care items or used as industrial resin pellets. ...
The occurrence of microplastics (MPs) in the environment has become an emerging global concern and has been reported to pose consequential risks to organisms, human health and the environment. Due to their small size (ranging from 1 μm to 5 mm in size), eliminating MPs from wastewater poses a significant challenge, which leads to their accumulation in wastewater treatment plants (WWTPs). This review article explores the method of characterizing MPs in WWTPs to understand their environmental impact better. It also discusses various techniques for characterising MPs in WWTPs, drawing on existing scientific literature. The article provides a comprehensive review of the current methodologies used for the characterisation (chemical, morphology, thermal) of MPs in WWTPs. Furthermore, analytical techniques such as scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy are discussed along with their limitations and potential for recognition and differentiation of various kinds of MPs. The article also highlights the need for standardisation of sampling, extraction, and analytical methods to ensure comparability of results from different studies. The review identifies several obstacles in characterising MPs within WWTPs, such as the absence of standardised methods, restricted detection thresholds, and challenges in quantifying MPs within intricate environmental contexts. To overcome these obstacles, the review recommends prioritising research efforts aimed at enhancing current methodologies, emphasising the need to refine techniques for better comprehension and analysis of MPs within WWTPs.
... For example, it was reported that the EC of algal strains (Chaetoceros muelleri and Tetraselmis suecica) on PMMA-MPs did not trigger toxicity of algal cells. Particularly, the interaction of 25 ppm MPs with algae has no obvious influence on nutrients absorption, propagation, and photosynthetic activity owing to their size and hydrophobicity (Bhargava et al., 2018). Wan et al. (2021) observed no negative impact due to the development of EC on the sur- negative impacts to microalgae Scenedesmus obliquus (Fig. 3(I)) (Zhou et al., 2020). ...
Microplastics (MPs) and nanoplastics (NPs) have been discovered in diverse environmental milieux, and they have attracted much attention due to their possible toxicological impacts on living organisms. Likewise, salts, organic chemicals, heavy metals, natural organic matter, and other biomolecules are ubiquitously in the ecosystem. In a natural environment, MPs and NPs can interact with natural organic matter and biomolecules because of their exceptional characteristics. They can develop corona-based complexes, including eco-corona (EC) or bio-corona (BC) on the surface of MPs and NPs that not only change physiochemical characteristics but also its fate, distribution, uptake, transportation, biotransformation, and toxicological performance. Unlike orthodox toxins, coronas-based complexes on MPs and NPs rather than pristine MPs/NPs may be more hazardous. Therefore, the current critical review aims to discuss the up-to-date status of the modulations in the toxicological behavior of coronas-based MPs and NPs complexes on different environmental species. Significantly, it also focuses on the factors affecting the modulations of toxicological behavior of eco- and bio-corona-based MPs and NPs complexes for better understanding the role of environmental variables on the toxicity of plastics particles. Furthermore, this review systematically highlighted that the effect of a coronas-based complexes on the toxicological behavior of MPs and NPs is multifarious and variable in terms of plastic particle sizes, biomolecule’s types, polymer types, environmental species, and designed experimental conditions. To sum up, the current review addresses existing knowledge gaps and suggests recommendations.
... In an aquatic environment, nanoplastic materials can affect organisms from various trophic levels, including bacteria [35], algae [36], arthropods [37], echinoderms [38], bivalves [39], rotifers [40], and fish [41]. Polystyrene nanoparticles accumulated in the yolk sac and migrated to the gastrointestinal tract, pancreas, liver, gallbladder, heart, and brain as early as 24 h and 120 h post-fertilization in developing zebra fish (Danio rerio) ...
... Within the first 3 h of incubation, poly methyl methacrylate NPs were ingested and translocated within the body of the barnacle nauplii. The outcomes of acute exposure demonstrate that NPs endure in the body during growth and development phases (Bhargava et al., 2018). ...
... Translocation of nanoplastic and microplastics of (mainly) polystyrene or polyethylene construction has been reported widely in the literature for aquatic invertebrates and vertebrates and from both laboratory exposures and field studies (e.g., Browne et al., 2008;Brennecke et al., 2015;Zhao et al., 2017;Bhargava et al., 2018). Regarding fish, microplastics have been reported in different organs (including those not involved in digestion) from various freshwater and marine species caught from the wild (Collard et al., 2017;Abbasi et al., 2018;McIlwraith et al., 2021). ...
The presence and effects of nanoplastics (NPs; <1 μm) in the aquatic environment are a growing concern. In this study, a model tooth-carp fish, Aphaniops hormuzensis, has been exposed to different concentrations of fluorescent polystyrene nanoplastics (PS-NP) in its diet (up to 5 mg kg−1) over periods of 28 d and the particle accumulation in different tissues determined. Accumulation was observed in both digestive and non-digestive organs, with concentrations greater in the gut, liver and gill (up to 400 μg kg−1 dw) than in the skin and muscle (<180 μg kg−1 dw), but no dependency on exposure time or dose was evident. The presence of the organic contaminant, triclosan (TCS), in the diet and at concentrations up to 0.5 μg kg−1 did not affect PS-NP uptake by A. hormuzensis, while TCS accumulation in the whole body increased with time (up to 10 μg kg−1) and, likewise, appeared to be unaffected by the presence of PS-NPs. These observations suggest that the two contaminants do not interact with each other or that any interactions have no impact on accumulation. The results of this study add to the growing body of evidence that NPs can be translocated by aquatic organisms after ingestion, and reveal that, for the species and conditions employed, nanoparticles are accumulated more readily than a widely used organic chemical.
... PE has an estimated lifetime of 33 years to be fully degraded by photo-oxidation as extrapolated from tests with a solar simulator system (14 ± 0.7 W·m −2 ) (Zhu et al., 2020). Indeed, the low photo-oxidation rate is attributed to the relatively low atmospheric temperature and fouling, meaning the coverage of the plastic with organic matter, reducing its exposition to solar light (Bhargava et al., 2018). Therefore, it is crucial to develop methods that improve the kinetics of existing processes or new ones. ...
For the past two decades, with the increase in plastic consumption came a rise in plastic waste, with the bulk of it ending up in landfills, incinerated, recycled or leaking into the environment, especially in aquatic ecosystems. Plastic waste poses a significant environmental threat and a wealth issue due to its non-biodegradability and recalcitrant nature. Polyethylene (PE) remains one of the major utilized polymers in different applications amid all the other types because of its low production costs, simplistic nature prone to be modified and historically predominant researched material. Since the common methods for plastic disposal are troubled by limitations, there is a growing need for more appropriate and environment friendly methods alternatives. This study highlights several ways that can be used to assist PE (bio)degradation and mitigate its waste impact. Biodegradation (microbiological activity driven) and photodegradation (radiation driven) are the most promising for PE waste control. The shape of the material (powder, film, particles, etc.), the medium degradation - composition, additives and pH, temperature and incubation, or exposure times are important in plastic degradation efficiency. Moreover, radiation pretreatment can enhance the biodegradability of PE, providing a promising approach to fighting plastic pollution. This paper relates the most significant results regarding PE degradation studies followed by weight loss (WL) analysis, surface morphology changes, oxidation degree (for photodegradation) and mechanical properties assessment. All these strategies are very promising methods to minimize the polyethylene impact. However, there is still a long way to go through. The degradation kinetics is still low for the currently available biotic or abiotic processes and complete mineralization is thoroughly unseen.
... In addition, the larvae may die due to the ingestion of nanoparticles. Ingestion of nanoparticles leads to increased weight, decreased swimming speed, and loss of natural swimming control and can affect normal growth (Bhargava et al. 2018). Based on the result of the MNPs deposition inside the barnacle guts, overcoming the ingestion and occurrence of the lethal effects can be disruptive to the sustainability of organism populations in aquatic ecosystems (Blinova et al. 2017). ...
To deal with the increasing consumption of metal oxide nanoparticles and carbon-based nanomaterials challenges, researchers have focused their attention on finding environmentally friendly paths for the synthesis of nanoparticles. In this study, a green approach synthesized graphene oxide-based nanoparticles from brown seaweed of Polycladia myrica, ZnO, and TiO2 nanoparticles. The nanoparticles were investigated with XRD, Raman, FESEM, EDS, mapping, and TEM. The bioactivity of antibacterial, anti-algae, and toxicity of barnacle larvae was evaluated for the nanoparticles. The best results were observed in the antibacterial test and toxicity of barnacle larvae in the graphene oxide reduced with P. myrica/zinc oxide (GZ) nanoparticles and anti-algae test in the graphene oxide reduced with P. myrica/zinc oxide/titanium dioxide (GTZ) nanoparticles. Compared with inorganic NPs, the nanoecotoxicological effects of GZ and GTZ nanoparticles are less studied in saltwater. However, the results presented in this study provide a better understanding of the antimicrobial, toxic potential, and benefits of green GZ and GTZ nanoparticles to replace them in an eco-friendly manner with a chemical counterpart for widespread biomedical applications.
Graphical Abstract
Herein, we wish to report a green approach for synthesized graphene oxide-based nanoparticles from brown seaweed of Polycladia myrica, ZnO, and TiO2 nanoparticles.
... Long-term exposure can better reflect the health effects of NPs on organisms. It was found that NPs would bioaccumulate even at low concentrations of plastic after long-term exposure and the absorption of NPs in the planktonic larval stage may continue to the adult stage (Bhargava et al. 2018). The effects of NPs on animals can be reflected through physiological and biochemical activities. ...
Nanoplastics (NPs) are emerging pollutants with great concern due to their small size and potential adverse effects on living organisms. This review summarizes the biological effects of NPs in vivo (plants and animals) and in vitro (cells). NPs can be ingested and accumulated in organisms and transferred along the food chain, affecting the growth, development, and reproduction at each trophic level. Several factors including surface charges, size, exposure dose, and exposure time affect the biological effects of NPs. Surface-charged NPs have a more significant impact on the normal physiological activities of cells, while smaller particles facilitate the penetration across the cell membranes. Higher doses and longer exposure time contribute to the higher accumulation. In addition, additives and environmental pollutants attached to NPs pose a greater threat to organisms than NPs themselves. There are still several analytical challenges in the study of the biological effects of NPs, especially their accumulation, degradation, migration and interactions with the biological systems. Further works on the risk assessment of NPs derived from commonly used plastics in our daily life like polyethylene terephthalate (PET) rather than laboratory-made polystyrene (PS) beads are still highly desired. Graphical Abstract: [Figure not available: see fulltext.]. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.
... The fluorescent dye was then purified by flowing through a SiO2 column with chloroform as the mobile phase (Figure 2), and the chloroform was removed from the product using a rotary evaporator. The fluorescent PMMA NPs were produced after an established nanoprecipitation technique [14][15][16][17][18]. In a typical procedure, a stock solution of PMMA (400 mg, MW: 15 000), SDS (7.7 mg, 26.6 μmol), and fluorescent perylene dye (17.4 mg, 26.6 μmol) was prepared in acetone (100 mL). 5 mL of this solution was combined with 50 mL of Milli-Q water and stirred for 24 h at 50 °C to remove excess acetone. ...
... Silent, small and almost invisible microplastics are entering our food chain (Figure 24; Bhargava et al. 2018;Seltenrich 2015). Seafood, a key dietary component for Box 14: How tiny plastics are entering our soil people living in Asia and the Pacific (Section 2.4), is likely to be the direct cause of human exposure to microplastics and other toxic compounds such as heavy metals and persistent organic pollutants. ...
... Apart from MPs, the toxicity of NPs to marine biota has been well documented, in terms of biological metabolism, inhibition of reproduction, growth, and development. For example, at chronic and acute exposure of 1 mg/L PMMA NPs (185 ± 3 nm), they were found to be systemically bioaccumulated in acorn barnacles [315]. PET NPs (20 or 60-80 nm) in solutions (1, 10, or 50 mg/L) exhibited size-and concentration-dependent toxicity to zebrafish embryos in terms of reactive oxygen species production, hatching, and heart rate [316]. ...
Plastics are widely used in our daily life; however, poor management and disposal result in their ubiquity throughout the biosphere. Increased accumulation of microplastic (MP) or even nanoplastic materials in the aquatic, terrestrial and atmospheric environment has produced significant impacts on life in water and on land. Currently, an incisive overview of MP contamination in the different environments is lacking, which impedes the effective formulation of strategical solutions. In this review, distribution, sources, transport, fate, and potential risks of MPs in water, air, and soil are comprehensively identified and analyzed. Integrated strategies are proposed to stop or mitigate their input into the environment, including cleanup activities, source control, improved plastic waste management, adoption of biodegradable (bio)plastics, and the development of advanced techniques for the degradation and conversion of (micro)plastic materials. Technologies for degradation including biodegradation, advanced oxidation processes, and conversion including bio-recycling, photocatalysis, pyrolysis, hydrocracking, hydrogenolysis, alkane metathesis, microwave-initiated conversion, flash Joule heating, electrocatalysis, dehydrochlorination, and chemical depolymerization are critically reviewed. Emphases are placed on catalytic system design, technological innovation, and related mechanisms. Finally, an outlook is presented on the challenges of MP pollution. Perspectives within and beyond the research field of science and technology-based solutions are also discussed.
... The results reported here are important to the emerging data on understanding the impact of polymer particles on human health. Further results can be referred to (Mahadevan & Valiyaveettil, 2021)), (Yip, Lee, Neo, Teo, & Valiyaveettil, 2021) and (Bhargava, et al., 2018). ...
This report outlines the outcomes of the APEC Workshop on Nanoplastics in Marine Debris held 13 – 15 December 2021. The agenda of the workshop is located in Annex A.
The main objective of the workshop was to promote communication and cooperation among policymakers and scientists from across the APEC region in addressing the emerging challenge of micro- and nanoplastics in marine debris, avoiding redundant efforts, and accelerating the development of this critical area of marine debris science for the benefit of the entire APEC community. The project to deliver the workshop was co-sponsored by Chile, Chinese Taipei, Thailand, Korea and the United States.
... Nanoplastic ingestion can cause the transfer of these pollutants to higher trophic levels, for example, trophic transfer from algal species to zooplanktons then to bigger fishes and finally to humans and other carnivores (Cedervall et al., 2012;Ng et al., 2018). They are found to permeate the intestinal walls of mussels (Bhattacharjee et al., 2014) and also cause bioaccumulation in barnacles (Bhargava et al., 2018). Their presence in the terrestrial environment confirms that they can be taken up by earthworms, plants and also by air pollution by aerolization of particulates (Chang et al., 2019). ...
Relationship Between Microbes and Environment for Sustainable Ecosystem Services, Volume Two: Microbial Mitigation of Waste for Sustainable Ecosystem Services promotes advances in sustainable solutions, value-added products, and fundamental research in microbes and the environment. Topics include advanced and recent discoveries in the use of microbes for sustainable development. Volume Two describes the successful application of microbes and their derivatives for waste management of potentially toxic and relatively novel compounds. This proposed book will be helpful to environmental scientists, experts and policymakers working in the field of microbe- based mitigation of environmental wastes. The book provides reference information ranging from the description of various microbial applications for the sustainability in different aspects of food, energy, environment industry and social development.
... PMMA is preferred in studies because of its convenience in synthesis processes compared to the other polymers. The toxicological tests of PMMA focus on animals (Bhargava et al., 2018). However, there are no reports about how the presence of PMMA interacts in the plant depending on biphasic dose-response called the hormesis effect. ...
Nanoplastic pollution has become an increasing problem due to over-consumption and degradation in ecosystems. A little is known about ecological toxicity and the potential risks of nanoplastics on plants. To better comprehend the hormetic effects of nanoplastics, the experimental design was conducted on the impacts of polymethyl methacrylate (PMMA) on water status, growth, gas exchange, chlorophyll a fluorescence transient, reactive oxygen species (ROS) content (both content and fluorescence visualization), lipid peroxidation and antioxidant capacity (comparatively between leaves and roots). For this purpose, PMMA (10, 20, 50 and 100 mg L-1) was hydroponically applied to Lactuca sativa for 15 days(d). PMMA exposure resulted a decline in the growth, water content and osmotic potential. As based on assimilation rate (A), stomatal conductance (gs), and intercellular CO2 concentrations (Ci), the decreased stomatal limitation (Ls) and, A/Ci and increased intrinsic mesophyll efficiency proved low carboxylation efficiency showing impaired photosynthesis as a non-stomatal limitation. PMMA toxicity increased the trapping fluxes and absorption with a decrease in electron transport fluxes caused the disruption in reaction centers of photosystems. The leaves and roots had a similar effect against PMMA toxicity, with increased superoxide dismutase (SOD) activity. Although, catalase (CAT) and peroxidase (POX) of leaves increased under 10 mg L-1 PMMA, these defense activities failed to prevent radicals from attacking. Compared to the leaves, the lettuce roots showed an intriguing result for AsA-GSH cycle against PMMA exposure. In the roots, the lowest PMMA application provided the high ascorbate/dehydroascorbate (AsA/DHA), GSH/GSSG and the pool of AsA/glutathione (GSH) and non-suppressed GSH redox state. Also, 10 mg L-1 PMMA helped remove high hydrogen peroxide (H2O2) by both glutathione peroxidase (GPX) and glutathione S-transferase (GST). Since this improvement in the antioxidant system could not be continued in roots after higher applications than 20 mg L-1 PMMA, TBARS (Thiobarbituric acid-reactive substances), indicating the level of lipid peroxidation, and H2O2 increased. Our findings obtained from PMMA-applied lettuce provide new information to advance the tolerance mechanism against nanoplastic pollution.
... Notwithstanding, studies by Molenaar et al. [139] reveal that the combination of sensitive fluorescence video microscopy, NileRed staining of plastic particles, and single-particle tracking can be used to count and size NPs with particle diameters as low as 45 nm while mixing ratios of differently sized particles can be recovered. Additionally, light scattering techniques like Dynamic Light Scattering (DLS), multiangle dynamic light scattering (MADLS), and static light scattering (STL) techniques can characterize the hydrodynamic diameter, zeta potential, electrophoresis mobility, and particle dispersity of MNPs [140,141]. Although the ability of DLS to resolve sizes in admixtures of particles with different diameters is limited, DLS, together with UV-Vis spectrophotometric and electron microscopic techniques could effectively monitor changes in the properties as well as ascertain the agglomeration and successive aggregation behavior of nanoparticles in myriad environmental compartments [142,143]. ...
The prevalence of micro and nanoplastics (MNPs) across the various environments and their negative impact on ecosystems have become a serious global threat and are currently a subject of many environmental concerns. Studies have provided evidence that MNPs have the potential to leach toxic plastic chemical additives and can adsorb a variety of persistent organic environmental pollutants, thereby enhancing their bioavailability, toxicity, and dispersion. Moreover, these MNPs easily penetrate the food chain and might cause health problems when ingested by humans and other organisms. Currently, there is complexity in understanding the mechanisms by which these toxic chemicals adsorb/desorb onto/from MNPs, and the physical and biological impacts of these chemical additives. To date, there is a considerable lack of knowledge on the major chemical additives of concern used in the plastic industry, their fate once MNPs dispose into the environment, the factors that affect their degradation, and their consequent impacts on human health. This review critically analyzes the current knowledge concerning the physical, chemical, and biological impacts of MNPs, and the various chemical and organic pollutants associated with MNPs. Emphasis was laid on their types, occurrence, fate, and distribution in the environment. The different techniques used in their identification, characterization, and removal were also elucidated. Furthermore, the consequent harmful effects of MNPs on human health were discussed to spur more future studies and fill knowledge gaps in this area.
... Notwithstanding, studies by Molenaar et al. [139] reveal that the combination of sensitive fluorescence video microscopy, NileRed staining of plastic particles, and single-particle tracking can be used to count and size NPs with particle diameters as low as 45 nm while mixing ratios of differently sized particles can be recovered. Additionally, light scattering techniques like Dynamic Light Scattering (DLS), multiangle dynamic light scattering (MADLS), and static light scattering (STL) techniques can characterize the hydrodynamic diameter, zeta potential, electrophoresis mobility, and particle dispersity of MNPs [140,141]. Although the ability of DLS to resolve sizes in admixtures of particles with different diameters is limited, DLS, together with UV-Vis spectrophotometric and electron microscopic techniques could effectively monitor changes in the properties as well as ascertain the agglomeration and successive aggregation behavior of nanoparticles in myriad environmental compartments [142,143]. ...
The prevalence of micro and nanoplastics (MNPs) across the various environments and their negative impact on ecosystems have become a serious global threat and are currently a subject of many environmental concerns. Studies have provided evidence that MNPs have the potential to leach toxic plastic chemical additives and can adsorb a variety of persistent organic environmental pollutants, thereby enhancing their bioavailability, toxicity, and dispersion. Moreover, these MNPs easily penetrate the food chain and might cause health problems when ingested by humans and other organisms. Currently, there is complexity in understanding the mechanisms by which these toxic chemicals adsorb/desorb onto/from MNPs, and the physical and biological impacts of these chemical additives. To date, there is a considerable lack of knowledge on the major chemical additives of concern used in the plastic industry, their fate once MNPs dispose into the environment, the factors that affect their degradation, and their consequent impacts on human health. This review critically analyzes the current knowledge concerning the physical, chemical, and biological impacts of MNPs, and the various chemical and organic pollutants associated with MNPs. Emphasis was laid on their types, occurrence, fate, and distribution in the environment. The different techniques used in their identification, characterization, and removal were also elucidated. Furthermore, the consequent harmful effects of MNPs on human health were discussed to spur more future studies and fill knowledge gaps in this area.
... Due to the low temperature, the rate of plastic degradation is decreased in the freshwater and oceanic ecosystem compared to the beach or terrestrial conditions (Ryan et al., 2009). Moreover, the oxidation reaction induced by the UV radiation is hindered by surface foulants and cuts the degradation weathering (Bhargava et al., 2018;Li, 2018). In the environment and sediment, the plastic reduction rate decreases the oxidation process (Froelich et al., 1979;Moore, 2008). ...
... MP ingestion and accumulation can occur across taxa in a sizedependent manner (Brennecke et al., 2015;Lee et al., 2022;Paul-Pont et al., 2018), with potential translocation, internalization, and health hazards within affected organisms Sendra et al., 2020). For example, sub-lethal exposure to MP in sea mussel larvae caused onset physical and transcriptional impairments post-ingestion (Capolupo et al., 2018), while ingested nano-sized MP in sea barnacles were effectively retained throughout all stages of larvae growth and expected to persist to adulthood (Bhargava et al., 2018). MP also have been documented in human stools with sizes ranging from 50 to 500 μm (Schwabl et al., 2019) and fine MP (ranging from 5 to 10 μm in size) were recently found translocated to placentas in unborn babies (Ragusa et al., 2021), indicating effective bioassimilation of miniscule plastics at cellular level once ingested and/or inhaled. ...
Accumulation of microplastics (MP) in oceanic waters is eroding the health of marine biota. We investigated how size-fractionated MP influence the toxicity risks towards a tropical keystone species, Perna viridis. Tissue-specific bioaccumulation and in vivo toxicity of polystyrene (PS) particles (0.5, 5, and 50 μm) were measured upon continuous exposure for 7 days, followed by 7 days depuration. P. viridis were exposed to equivalent mass (0.6 mg/L), corresponding to 4.0-4.6 particles/mL, 4.6-7.1 × 103 particles/mL, and 1.1-4.8 × 106 particles/mL for 50 μm, 5 μm and 0.5 μm PS particles, respectively. Onset toxicity were quantified through the enhanced integrated multi-biomarker response (EIBR) model, measured by weighting of biological organisation levels of eight biomarkers: (i) molecular (i.e., DNA damage (comet), 7-ethoxy resorufin O-deethylase (EROD), Catalase (CAT), Superoxide dismutase (SOD), Ferric Reducing Antioxidant Power (FRAP)); (ii) cellular (i.e., Neutral red retention (NRR), phagocytosis); and (iii) physiological (i.e., filtration rate). Data showed slightly elevated lysosomal instability (NRR) and antioxidant defences (FRAP, SOD, CAT, EROD) in specimens exposed to nano-PS (0.5 μm) compared to micro-PS (5 and 50 μm). Immunotoxicity (phagocytosis) and genotoxicity (comet) for haemocyte cells were significantly higher in specimens exposed to nano-PS (p < 0.05). EIBR index corroborated increasing toxicity modulated by MP sizes in descending order: 0.5 μm > 5 μm > 50 μm, with nano-PS exerted significantly higher biological effects (EIBR = 19.77 ± 5.89) than the unexposed group (EIBR = 10.97 ± 2.02; p < 0.05). Symptomatic organismal depression was manifested by the depleting filtering proficiency and weakened defence against invasive Zymosan bioparticles in the phagocytosis assay. Although impaired mussels duly recovered during depuration, individuals affected by nano-PS showed immunocompetence deficiency and gill responses that were not readily reversible, which could potentially increase their vulnerability towards further environmental stressors.
... A promising approach seems to be the use of fluorescent material. Fluorescent microplastics and nanoparticles have been used in many studies investigating the fate of the material during exposure and bioaccumulation studies (Assas et al., 2020;Bhargava et al., 2018;Elizalde-Velázquez et al., 2020;Kuehr, Diehle, et al., 2021;Kuehr et al., 2022;Liu et al., 2021). Nevertheless, in most cases, fluorescence was used to localize the particles or to count the number of particles (Assas et al., 2020;Liu et al., 2021). ...
Bioaccumulation tests with invertebrates have recently been discussed as a suitable alternative to bioaccumulation tests with metal‐ or metal oxide‐based nanoparticles in fish for regulatory assessment. In this study, as a first step, we investigated the suitability of three invertebrate species for bioaccumulation tests with nano‐ and microplastics. In a laboratory approach the freshwater bivalve Corbicula fluminea, the freshwater amphipod Hyalella azteca, and the terrestrial isopod Porcellio scaber were exposed to fluorescent labelled nano‐ and microplastics to evaluate their suitability to estimate the bioavailability and bioaccumulation of these test items. No bioaccumulation was observed in H. azteca or P. scaber. In contrast, the measurement of the relative fluorescence of the test items in the soft tissue and the feces of the filter‐feeding bivalve allowed to derive data that may be useful for the regulatory bioaccumulation assessment of manufactured nano‐ and microplastics. The developed measurement method using fluorescence represents a time‐efficient and cost‐effective analytical method for manufactured nano‐ and microplastics in laboratory studies for regulatory assessment. This article is protected by copyright. All rights reserved.
... Increased concentrations of nanoplastics lead to the disruption of the metabolic processes by enhancing the concentration of ethanol, lysine and adenosine in the liver of the fishes (Crossman 2020). Bhargava et al. in 2018 have assessed the aggregations of nanoplastics inside the body of the barnacles (marine crustacean) by conducting toxicity tests. Results indicate that continuous exposure leads to the alteration of the signal molecules resulting in the interference of lipid metabolism. ...
Polyethylene terephthalate is a common plastic in many products such as viscose rayon for clothing, and packaging material in the food and beverage industries. Polyethylene terephthalate has beneficial properties such as light weight, high tensile strength, transparency and gas barrier. Nonetheless, there is actually increasing concern about plastic pollution and toxicity. Here we review the properties, occurrence, toxicity, remediation and analysis of polyethylene terephthalate as macroplastic, mesoplastic, microplastic and nanoplastic. Polyethylene terephthalate occurs in groundwater, drinking water, soils and sediments. Plastic uptake by humans induces diseases such as reducing migration and proliferation of human mesenchymal stem cells of bone marrow and endothelial progenitor cells. Polyethylene terephthalate can be degraded by physical, chemical and biological methods.
... The lower size of NPs may favour the internalization of sorbed pollutants potentially inducing enhanced toxic responses (Bhargava et al., 2018). ...
The knowledge about the interaction of nanoplastics with other aquatic pollutants and their combined effects on biota is very scarce. In this work, we studied the interaction between polystyrene nanoplastics (PS NPs) (30 nm) and the micropollutants in a biologically treated wastewater effluent (WW). The capacity of PS NPs to sorb micropollutants was studied as well as their single and combined toxicity towards three freshwater organisms: the recombinant bioluminescent cyanobacterium, Anabaena sp. PCC 7120 CPB4337; the duckweed, Spirodela polyrhiza and the cladoceran, Daphnia magna. The endpoints were the inhibition of bioluminescence, the growth inhibition of the aquatic plant and the immobilization of D. magna after 24, 72 and 48 h of exposure, respectively. Combination Index (CI)-isobologram method was used to quantify mixture toxicity and the nature of interactions. PS NPs sorbed a variety of chemicals present in WW as micropollutants in a range of tens of ng/L to μg/L. It was found that those pollutants with positive charge were the main ones retained onto PS NPs, which was attributed to the electrostatic interaction with the negatively charged PS NPs. Regarding the toxicological effects, single exposure to PS NPs affected the three tested organisms. However, single exposure to WW only had a negative impact on the cyanobacterium and S. polyrhiza with no observed toxicity to D. magna. Regarding PS NPs-WW combined exposure, a reduction of toxicity in comparison with single exposure was observed probably due to the sorption of micropollutants onto PS NPs, which resulted in lower bioavailability of the micropollutants. In addition, the formation of PS NPs-WW heteroaggregates was observed which could result in lower bioavailability of PS NPs and sorbed micropollutants, thus lowering toxicity. This study represents a near-realistic scenario approach to the potential sorption of wastewater pollutants onto nanoplastics that could alter the toxicological effect on the biota.
The large-scale manufacturing, extensive use, ineffective management, and improper disposal of plastics and
plastic-containing products have made them one of the most significant environmental concerns of today. The
transport of micro and nano plastics (MNPs) between terrestrial and freshwater environmental compartments,
including reciprocal contributions and inherent connections, and the effects of MNPs on the primary producers in
various ecosystems, are two pertinent research areas. Herein, we provide a critical overview of the accumulation
of MNPs by primary producers in the freshwater and terrestrial biota. On the one hand, we examined the
occurrence of MNPs and their effects on freshwater species in natural systems, and laboratory-based ecotoxicological
effects of ingesting MNPs. On the other hand, MNP distribution in the soil environment, root uptake
processes, and mode of action, still largely unknown, were assessed to highlight terrestrial ramifications. To this
end, the presence, phytotoxicity, distribution, absorption, and function of MNPs in different soil types were
examined. This review also discussed the potential for remediating MNPs in soil via the formation of eco-corona,
and how eco-corona formation aids in lowering MNP toxicity in freshwater algae and terrestrial plants.
Nanoplastics (plastic particles smaller than 1 μm) are the least-known type of marine litter. Nanoplastics (NPs) have attracted much interest in recent years because of their prevalence in the environment and the potential harm they can cause to living organisms. This article focuses on understanding NPs and their fate in the marine environment. Sources of NPs have been identified, including accidental release from products or through nano-fragmentation of larger plastic debris. As NPs have a high surface area, they may retain harmful compounds. The presence of harmful additives in NPs poses unique practical challenges for studies on their toxicity. In this review, several methods specifically adapted for the physical and chemical characterization of NPs have been discussed. Furthermore, the review provides an overview of the translocation and absorption of NPs into organisms, along with an evaluation of the release of potential toxins from NPs. Further, we have provided an overview about the existing methods suggested for the possible degradation of these NPs. We conclude that the hazards of NPs are plausible but unknown, necessitating a thorough examination of NPs’ sources, fate, and effects to better mitigate and spread awareness about this emerging contaminant.
The current experiment measured the multifaceted effects of polystyrene and fluoranthene, acting alone or in a mixture on marine meiofauna, but with a special focus on nematodes' morphological and functional traits. The results showed changes in the abundances for all tested concentrations of both compounds. The nematode communities exposed to the highest concentrations of fluoranthene (30 ng.g-1 Dry Weight (DW)) and polystyrene (100 mg.kg-1 DW) alone or in a mixture, were significantly less diverse compared to control and were associated with significant changes in the percentage of taxonomic composition and feeding-guilds. The most sensitive taxa to fluoranthene comprised epistratum feeders, whereas the nematodes mostly affected by polystyrene were omnivores-carnivores. A new functional tool, the Index of Sensitivity (IOS), proved to be reliable in depicting the changes that occurred in the taxonomic and functional features of the nematofauna.
The current experiment measured the multifaceted effects of polystyrene and fluoranthene, acting alone or in a mixture, on the meiobenthic nematode species Oncholaimus campylocercoides. This Oncholaimid was first experimentally selected from an entire nematode assemblage taken from the Jeddah coasts (Saudi Arabia). Several discernible changes were found in morphometry and functional traits after exposure to single and combined treatments. An increase in the activity of the biochemical biomarkers catalase and glutathione S-transferase was also observed following the exposure of males and gravid females of O. campylocercoides to 37.5 ng fluoranthene·g-1 dry weight (DW) and 62.5 mg polystyrene·kg-1 DW paralleled by a higher vulnerability of females. Moreover, the reproduction and feeding of this species were impaired, starting from 37.5 ng fluoranthene·g-1 and 62.5 mg polystyrene·kg-1, respectively. These results have been confirmed by good binding affinities and molecular interactions of fluoranthene and polystyrene with both GLD-3 and SDP receptors.
Plastics have been used for about 100 years, and daily-use products composed of plastics are now prevalent. As a result, humans are very easily exposed to the plastic particles generated from the daily-use plastics. However, studies on cellular uptake of nanoplastics in "human cells" have only recently begun to attract attention. In previous studies, definitions of nanoplastics and microplastics were vague, but recently, they have been considered to be different and are being studied separately. However, nanoplastics, unlike plastic particles of other sizes such as macro- and microplastics, can be absorbed by human cells, and thus can cause various risks such as cytotoxicity, inflammation, oxidative stress, and even diseases such as cancer82, 83. and diabetes (Fan et al., 2022; Wang et al., 2023). Thus, in this review, we defined microplastics and nanoplastics to be different and described the potential risks of nanoplastics to human caused by cellular uptake according to their diverse factors. In addition, during and following plastic product usage a substantial number of fragments of different sizes can be generated, including nanoplastics. Fragmentation of microplastics into nanoplastics may also occur during ingestion and inhalation, which can potentially cause long-term hazards to human health. However, there are still few in vivo studies conducted on the health effect of nanoplastics ingestion and inhalation.
Polystyrene (PS) often found in the ocean is one of the most commonly used plastic polymers in the world and can exist in different particle sizes. In particular, PS degrades relatively faster and widely accumulates at the nanoscale. Therefore, the penetration is strong and it is easy to enter the body and cause adverse effects. However, the persistence or recovery of their toxicity remains largely unclear. Here, we designed two subexperiments (exposure and recovery experiments) and investigated the persistence of the toxicity of polystyrene (PS) NPs at a wide concentration range (0.01-10 mg/L) to diatoms (Phaeodactylum tricornutum). PS-NPs significantly inhibited algal growth and clearly wrinkled the surfaces of cells, membrane permeability was significantly increased, and the steady-state state of cell redox and mitochondrial membrane potential was disturbed. However, in the recovery experiment, the increased membrane permeability was observed to persist, but the induced oxidative damage was reversible, and the absorbed NPs could be excreted. Integrated omics techniques (metabolomics and transcriptomics) revealed that PS-NPs significantly disrupts cell metabolism, including disturbances in fatty acid biosynthesis and enhanced biosynthesis of phenylalanine, tyrosine, and tryptophan. Inhibition of fatty acid, amino acid, energy and carbohydrate metabolism and disturbance of the antioxidant system contribute to the persistence of toxicity. These findings highlight the phenomena and mechanisms of the persistence of phytotoxicity and are critical to the accurate assessment of NPs.
Plastics consist of a wide range of synthetic or semi-synthetic organic compounds, usually polymers with a high molecular mass (e.g. polyethylene – PE, polyvinyl chloride – PVC, polystyrene – PS, polyhydroxybutyrate – PHB, polylactic acid – PLA, polyethylene terephthalate – PET, polyacrylonitrile – PAN, and poly(methyl methacrylate) – PMMA). For many decades, their production and use continued to increase worldwide, and numerous studies reported their increasing density in natural environments.1 The process of complete degradation of plastics in natural environments takes from several months to many decades.2 Increasing attention over the last 15 years has been directed toward the proliferation and potential environmental impact of microplastics (MPs),3 usually defined as plastic particles smaller than 5 mm in the largest dimension,4 particularly in aquatic habitats. Although according to the definition there is no lower limit of the particles’ size, experimental studies on microplastics are usually based on particles in the micro- rather than nanometre range. Many studies have attempted to estimate the distribution and concentration of MPs in various environments and to determine how MPs affect their inhabitants. Numerous studies have revealed that many organisms in natural environments ingest MPs,4 and that the harmfulness of ingested MPs depends on particle type, size, density or even colour, and may be due to mechanical (e.g. clogging the digestive tract, adhering to external surfaces thereby hindering mobility) and chemical effects. Chemical harmfulness results from both the presence of additives (e.g. plasticizers antioxidants, flame retardants and UV stabilizers) that have the potential to leach into the environment causing damage to organisms, and the ability to accumulate harmful hydrophobic substances from the surrounding water.5,6 Although numerous studies have indicated the various negative effects of MPs, the risk assessment analysis suggested that their effect is rather negligible,7–9 since environmental MP densities (usually being in the range of ng and low µg L−1)10,11 are much below the threshold densities that lead to harmful effects (usually from several mg L−1).
Africa is a large continent ranked amongst the top consumer of plastic materials. However, the improper handling of plastic wastes has resulted in massive pollution of different aspects of the environment (water, soil, sediments, air, food, etc.) within and around the region. The fragmentation and biodegradation of the bulk plastic material into small-sized particles has given rise to microplastic and nanoplastics. Owing to their small sizes, ease of transport, and large surface area, they tend to wreak serious havoc in the environment. Nevertheless, the growing awareness of the pollution problems caused by micro/nanoplastic debris is instrumental towards circumventing its widespread across the ecosystem. This review provides a state-of-the-art information on the prevailing nanoplastic surge across the borders of Africa, the ineffective management policies of plastic wastes, potential environmental hazards, and possible remediation strategies. Additionally, prospective insights into new areas for advanced research were highlighted.
Due to the small size, high mobility and large surface area, nanoplastics (NPs) showed high potential risks to aquatic organisms. This paper reviews the toxicity of NPs to aquatic organism at various trophic levels including bacteria, plankton (algae), zooplankton, benthos, and nekton (fish). The effects at individual level caused by NPs were explained and proved by cytotoxicity and genotoxicity, and the toxicity of NPs beyond individual level was also illustrated. The toxicity of NPs is determined by the size, dosage, and surface property of NPs, as well as environmental factors, the presence of co-contaminants and the sensitivity of tested organisms. Furthermore, the joint effects of NPs with other commonly detected pollutants such as organic pollutants, metals, and nanoparticles etc. were summarized. In order to reflect the toxicity of NPs in the real natural environment, studies on toxicity assessment of NPs with the coexistence of various environmental factors and contaminants, particularly under the concentrations in natural environment are suggested.
Nanoplastics (NPs), small (< 1 µm) polymer particles formed from bulk plastics, are a potential threat to human health and the environment. Orders of magnitude smaller than microplastics (MPs), they might behave different due to their larger surface area and small size, which allows them to diffuse through organic barriers. However, detecting NPs in the environment and organic matrices has proven to be difficult, as their chemical nature is similar to these matrices. Furthermore, as their size is smaller than the (spatial) detection limit of common analytic tools, they are hard to find and quantify. Here, we highlight different micro‐spectroscopic techniques utilized for NP detection and argue that an analysis procedure should involve both particle imaging and correlative or direct chemical characterization of the same particles or samples. Finally, we highlight methods that can do both simultaneously, but have as downside that large particle numbers and statistics cannot be obtained.
Nanoplastics (NPs), small (<1 μm) polymer particles formed from bulk plastics, are a potential threat to human health and the environment. Orders of magnitude smaller than microplastics (MPs), they might behave differently due to their larger surface area and small size, which allows them to diffuse through organic barriers. However, detecting NPs in the environment and organic matrices has proven to be difficult, as their chemical nature is similar to these matrices. Furthermore, as their size is smaller than the (spatial) detection limit of common analytical tools, they are hard to find and quantify. We highlight different micro‐spectroscopic techniques utilized for NP detection and argue that an analysis procedure should involve both particle imaging and correlative or direct chemical characterization of the same particles or samples. Finally, we highlight methods that can do both simultaneously, but with the downside that large particle numbers and statistics cannot be obtained.
Many organisms are consuming food contaminated with micro- and nanoparticles of plastics, some of which absorb persistent organic pollutants (POPs) from the environment and acting as carrier vectors for increasing the bioavailability in living organisms. We recently reported that polymethylmethacrylate (PMMA) nanoparticles at low concentrations are not toxic to animal models tested. In this study, the toxicity of diphenylamine (DPA) incorporated PMMA nanoparticles are assessed using barnacle larvae as a model organism. The absorption capacity of DPA from water for commercially available virgin PMMA microparticles is relatively low (0.14 wt%) during a 48 h period, which did not induce exposure toxicity to barnacle nauplii. Thus, PMMA nanoparticles encapsulated with high concentrations of DPA (DPA-enc-PMMA) were prepared through a reported precipitation method to achieve 40% loading of DPA inside the particles. Toxicity of DPA-enc-PMMA nanoparticles were tested using freshly spawned acorn barnacle nauplii. The observed mortality of nauplii from DPA-enc-PMMA exposure was compared to the values obtained from pure DPA exposure in water. The mortality among the exposed acorn barnacle nauplii did not exceed 50% even at a high concentration of DPA inside the PMMA nanoparticles. The results suggest that the slow release of pollutants from polymer nanoparticles may not induce significant toxicity to the organism living in a dynamic environment. The impact of long-term exposure of DPA absorbed plastic nanoparticles need to be investigated in the future.
Currently, nanomaterials form an integral part of several industrial products that include household utility items, agricultural and food commodities, pharmaceutical actives, textiles, plastics, cosmetics, energy resources, medical devices, and implants. This is because metal particles and materials in their nano form have inherently remarkable properties that are very different from their macro forms, due to their high surface area to volume ratio. But their “cradle to grave” life cycles reveal many of them to be nanopollutants that persist and accumulate in the environment to cause toxicity concerns at several levels of the ecological pyramid. It mandates their remediation to make them environmentally benign for industrial usage. Adopting physiochemical strategies for this purpose may not be eco-friendly due to the usage of petroleum solvents and harsh chemicals. On the other hand, several naturally occurring microbial organisms, including bacteria and fungi, can achieve remediation of nanopollutants and provide flexible, low-cost, recyclable, and green solutions for their detoxification. Further, genetically engineered microorganisms are also potentially resourceful, especially for rapid remediation. This chapter deals with such versatile microbes, currently employed for this purpose, along with futuristic microbial strategies for the same.
Concerns about the micro/nano plastics (MNPs) exposure risks have risen in recent years. The ecological corona (EC), which is generated by the interaction between MNPs and environmental substances, has a significant impact on their environmental fate and ecological risks. As the largest sink of MNPs, the aquatic environment is of great significance for understanding the environmental behaviour of MNPs. Transmission Electron Microscope (TME), Fourier Transform Infra-Red (FTIR), Scanning Electron Microscope (SEM), Dynamic Light Scattering (DLS) and other analytical methods have been used as effective methods to analyse the formation process of EC and detect the existing EC directly or indirectly on the surface of MNPs. The physicochemical properties of MNPs, complex aquatic environments and ageing time have been identified as the key factors affecting EC formation in aquatic environments. Moreover, the EC absorbed on MNPs significantly changed their environmental behaviour and toxicity to aquatic organisms. This review gives a full understanding of the EC formation progress on the surface of MNPs and different analytical methods for EC have been summarised which can further assist the ecological risk assessment of MNPs in the aquatic environment.
Plastics enter the environment and break up into microplastics (MPs) and even nanoplastics (NPs) by biotic and abiotic weathering. These small particles are widely distributed in the environmental media and extremely mobile and reactive, easily suspending in the air, infiltrating into the soil, and interacting with biota. Current research on MPs/NPs is either in the abiotic or biotic compartments, with little attention paid to the fact that the biosphere as a whole. To better understand the complex and continuous movement of plastics from biological to planetary scales, this review firstly discusses the transport processes and drivers of microplastics in the macroscopic compartment. We then summarize insightfully the uptake pathways of MPs/NPs by different species in the ecological compartment and analyze the internalization mechanisms of NPs in the organism. Finally, we highlight the bioaccumulation potential, biomagnification effects and trophic transfer of MPs/NPs in the food chain. This work is expected to provide a meaningful theoretical body of knowledge for understanding the biogeochemical cycles of plastics.
Most of the things we see around are made up of plastics. From stores to homes, it has made its way into each economic sector. The most extensively used is polystyrene which has been widely used in the food industry, cutlery, industrial packaging, building insulation, medicinal equipment, toys, etc. Due to insufficient recycling and its non-biodegradable nature, these products end up in landfills and water bodies. Once introduced in the environment, polystyrene can undergo degradation and disintegration, mechanical abrasion and other processes that result in the formation of smaller sized microplastics that would eventually degrade into nanoplastics. Thus, these products are a significant source of polystyrene nanoplastics (PSNPs). Studies suggest that PSNPs penetrate living organisms through multiple routes via skin, respiratory and digestive tracts and consequently, their accumulation along the food chain takes place. Widespread research is going on to study the impact of polystyrene nanoplastics on different ecosystems and their species. The main focus of this review has been on the numerous sources of PSNPs, toxicity involving marine and terrestrial ecosystems and different remediation techniques such as photocatalysis, adsorption using biochar, flocculation, filtration, the electrospun membrane system and bioremediation measures that could be a possible solution to the major ecological crisis caused by PSNPs.
Nanoplastics are being detected with increasing frequency in aquatic environments. Although evidence suggests that nanoplastics can cause overt toxicity to biota across different trophic levels, but there is little understanding of how materials such as differently charged polystyrene nanoplastics (PS-NP) impact fish development and behavior. Following exposure to amino-modified (positive charge) PS-NP, fluorescence accumulation was observed in the zebrafish brain and gastrointestinal tract. Positively charged PS-NP induced stronger developmental toxicity (decreased spontaneous movement, heartbeat, hatching rate, and length) and cell apoptosis in the brain and induced greater neurobehavioral impairment as compared to carboxyl-modified (negative charge) PS-NP. These findings correlated well with fluorescence differences indicating PS-NP presence. Targeted neuro-metabolite analysis by UHPLC-MS/MS reveals that positively charged PS-NP decreased levels of glycine, cysteine, glutathione, and glutamic acid, while the increased levels of spermine, spermidine, and tyramine were induced by negatively charged PS-NP. Positively charged PS-NP interacted with the neurotransmitter receptor N-methyl-D-aspartate receptor 2B (NMDA2B), whereas negatively charged PS-NP impacted the G-protein-coupled receptor 1 (GPR1), each with different binding energies that led to behavioral differences. These findings reveal the charge-specific toxicity of nanoplastics to fish and provide new perspective for understanding PS-NP neurotoxicity that is needed to accurately assess potential environmental and health risks of these emerging contaminants.
Microplastics have become a significant environmental problem worldwide. Compared with microplastics, nanoplastics are apparently more abundant and harmful but their environmental processes are less well understood. The fate and ecological impacts of nanoplastics in aquatic environments are largely determined by their aggregation properties, which were investigated here using pure water and artificial seawater prepared in the laboratory, as well as river water and coastal seawater collected from subtropical Hong Kong. The tests were carried out at an environmentally realistic temperature range (15–35 °C) with particle concentrations over four orders of magnitude (0.1–100 mg L⁻¹). Under these experimental conditions, parameters of dynamic light scattering were used to determine the extent of aggregation and colloidal stability of polystyrene nanospheres (nPS), a common test model of nanoplastics. Our results showed that aggregation of nPS was minimal in pure water and river water, but became strong under the ionic strength of artificial seawater and coastal seawater, in which 70 nm nPS could aggregate to >2000 nm, and this aggregation clearly increased with increase in temperature and particle concentration. The aggregates with increasing size and decreasing colloidal stability were deposited more quickly. Findings from this study imply an increased risk of nanoplastics to marine benthic organisms through the aggregation and deposition processes, particularly in warmer waters.
Microplastics have been documented in marine environments worldwide, where they pose a potential risk to biota. Environmental interactions between microplastics and lower trophic organisms are poorly understood. Coastal shelf seas are rich in productivity but also experience high levels of microplastic pollution. In these habitats, fish have an important ecological and economic role. In their early life stages, planktonic fish larvae are vulnerable to pollution, environmental stress and predation. Here we assess the occurrence of microplastic ingestion in wild fish larvae. Fish larvae and water samples were taken across three sites (10, 19 and 35 km from shore) in the western English Channel from April to June 2016. We identified 2.9% of fish larvae (n = 347) had ingested microplastics, of which 66% were blue fibres; ingested microfibers closely resembled those identified within water samples. With distance from the coast, larval fish density increased significantly (P < 0.05), while waterborne microplastic concentrations (P < 0.01) and incidence of ingestion decreased. This study provides baseline ecological data illustrating the correlation between waterborne microplastics and the incidence of ingestion in fish larvae.
We investigated microplastics in the digestive tracts of 64 Japanese anchovy (Engraulis japonicus) sampled in Tokyo Bay. Plastic was detected in 49 out of 64 fish (77%), with 2.3 pieces on average and up to 15 pieces per individual. All of the plastics were identified by Fourier transform infrared spectroscopy. Most were polyethylene (52.0%) or polypropylene (43.3%). Most of the plastics were fragments (86.0%), but 7.3% were beads, some of which were microbeads, similar to those found in facial cleansers. Eighty percent of the plastics ranged in size from 150 μm to 1000 μm, smaller than the reported size range of floating microplastics on the sea surface, possibly because the subsurface foraging behavior of the anchovy reflected the different size distribution of plastics between surface waters and subsurface waters. Engraulis spp. are important food for many humans and other organisms around the world. Our observations further confirm that microplastics have infiltrated the marine ecosystem, and that humans may be exposed to them. Because microplastics retain hazardous chemicals, increase in fish chemical exposure by the ingested plastics is of concern. Such exposure should be studied and compared with that in the natural diet.
Microplastics result from fragmentation of plastic debris or are released to the environment as preproduction pellets or components of consumer and industrial products. In the oceans, they contribute to the 'great garbage patches'. They are ingested by many organisms, from protozoa to baleen whales, and pose a threat to the aquatic fauna. Although as much as 80% of marine debris originates from land, little attention was given to the role of rivers as debris pathways to the sea. Worldwide, not a single great river has yet been studied for the surface microplastics load over its length. We report the abundance and composition of microplastics at the surface of the Rhine, one of the largest European rivers. Measurements were made at 11 locations over a stretch of 820 km. Microplastics were found in all samples, with 892,777 particles km(-2) on average. In the Rhine-Ruhr metropolitan area, a peak concentration of 3.9 million particles km(-2) was measured. Microplastics concentrations were diverse along and across the river, reflecting various sources and sinks such as waste water treatment plants, tributaries and weirs. Measures should be implemented to avoid and reduce the pollution with anthropogenic litter in aquatic ecosystems.
Silver nanoparticles (AgNPs), owing to their unique physical and chemical properties, have become increasingly popular in consumer products. However, data on their potential biological effects on marine organisms, especially invertebrates, remain very limited. This proof of principle study reports the chronic sub-lethal toxicity of two coated AgNPs (oleic acid coated AgNPs and polyvinylpyrrolidone coated AgNPs) on marine benthic invertebrate larvae across three phyla (i.e., the barnacle Balanus Amphitrite, the slipper-limpet Crepidula onyx, and the polychaete Hydroides elegans) in terms of growth, development, and metamorphosis. Bioaccumulation and biodistribution of silver were also investigated. Larvae were also exposed to silver nitrate (AgNO3) in parallel to distinguish the toxic effects derived from nano-silver and the aqueous form of silver. The sub-lethal effect of chronic exposure to coated AgNPs resulted in a significant retardation in growth and development, and reduction of larval settlement rate. The larval settlement rate of H. elegans was significantly lower in the coated AgNP treatment than the AgNO3 treatment, suggesting that the toxicity of coated AgNPs might not be solely evoked by the release of silver ions (Ag+) in the test medium. The three species accumulated silver effectively from coated AgNPs as well as AgNO3, and coated AgNPs were observed in the vacuoles of epithelial cell in the digestive tract of C. onyx. Types of surface coatings did not affect the sub-lethal toxicity of AgNPs. This study demonstrated that coated AgNPs exerted toxic effects in a species-specific manner, and their exposure might allow bioaccumulation of silver, and affect growth, development, and settlement of marine invertebrate larvae. This study also highlighted the possibility that coated AgNPs could be taken up through diet and the toxicity of coated AgNPs might be mediated through toxic Ag+ as well as the novel modalities of coated AgNPs.
The uptake and toxicity of two poly(methylmethacrylate)-based plastic nanoparticles (PNPs) with different surface chemistries (medium and hydrophobic) was assessed using aquatic organisms selected for their relevance based on the environmental behaviour of the PNPs. Pure poly(methylmethacrylate) (medium; PMMA PNPs) and poly(methylmethacrylate-co-stearylmethacrylate) copolymer (hydrophobic; PMMA-PSMA PNPs) of 86-125 nm were synthesised using a mini emulsion polymerisation method. Fluorescent analogues of each PNP (FPNPs) were also synthesised using monomer 7-[4-(trifluoromethyl)coumarin]acrylamide and studied. Daphnia magna, Corophium volutator and Vibrio fischeri were employed in a series of standard acute ecotoxicity tests, being exposed to the PNPs at three different environmentally realistic concentrations (0.01, 0.1, and 1.0 mg L(-1) ) and a high concentration 500-1000 mg L(-1) . In addition, sublethal effects of PNPs in C. volutator were determined using a sediment reburial test whilst the uptake and depuration of FPNPs was studied in D. magna. The PNPs and FPNPs did not exhibit any observable toxicity at concentrations up to 500-1000 mg L(-1) in any of the tests except for PMMA-PSMA PNPs and FPNPs following 48 h exposure to D. magna (LC50 values of 879 and 887 mg L(-1) , respectively). No significant differences were observed between labelled and non-labelled PNPs, indicating the suitability of using fluorescent labelling. Significant uptake and rapid excretion of the FPNPs was observed in D. magna. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
Barnacle Amphibalanus amphitrite adults were collected from the Jeddah coast of the Red Sea during different seasons. The nauplii released by adults in autumn, winter, spring and summer were reared under laboratory conditions to know the larval development duration and settlement in relation to the hatching season. The nauplii reared during winter (11 days) and autumn (13 days) took longer to reach the cypris stage compared to nauplii reared in summer (6 days) and spring (7 days). The most successful settlement of larvae was observed in spring and summer and the least successful - in winter. The observations of gonads showed that summer and spring are the active breeding season for A. amphitrite in the Red Sea. The results of this study indicated that the nauplii hatching season plays a significant role in the larval development and settlement of barnacles in the Red Sea.
The radial growth and advancement of the adhesive interface to the substratum of many species of acorn barnacles occurs underwater and beneath an opaque, calcified shell. Here, the time-dependent growth processes involving various autofluorescent materials within the interface of live barnacles are imaged for the first time using 3D time-lapse confocal microscopy. Key features of the interface development in the striped barnacle, Amphibalanus (= Balanus) amphitrite were resolved in situ and include advancement of the barnacle/substratum interface, epicuticle membrane development, protein secretion, and calcification. Microscopic and spectroscopic techniques provide ex situ material identification of regions imaged by confocal microscopy. In situ and ex situ analysis of the interface support the hypothesis that barnacle interface development is a complex process coupling sequential, timed secretory events and morphological changes. This results in a multi-layered interface that concomitantly fulfills the roles of strongly adhering to a substratum while permitting continuous molting and radial growth at the periphery.
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We report the uptake of MSNs into the roots and their movement to the aerial parts of four plant species and their quantification using fluorescence, TEM and proton-induced x - ray emission (micro - PIXE) elemental analysis. Monodispersed mesoporous silica nanoparticles (MSNs) of optimal size and configuration were synthesized for uptake by plant organs, tissues and cells. These monodispersed nanoparticles have a size of 20 nm with interconnected pores with an approximate diameter of 2.58 nm. There were no negative effects of MSNs on seed germination or when transported to different organs of the four plant species tested in this study. Most importantly, for the first time, a combination of confocal laser scanning microscopy, transmission electron microscopy and proton-induced X-ray emission (micro-PIXE) elemental analysis allowed the location and quantification MSNs in tissues and in cellular and sub-cellular locations. Our results show that MSNs penetrated into the roots via symplastic and apoplastic pathways and then via the conducting tissues of the xylem to the aerial parts of the plants including the stems and leaves. The translocation and widescale distribution of MSNs in plants will enable them to be used as a new delivery means for the transport of different sized biomolecules into plants.
Plastic debris litters aquatic habitats globally, the majority of which is microscopic (< 1 mm), and is ingested by a large range of species. Risks associated with such small fragments come from the material itself and from chemical pollutants that sorb to it from surrounding water. Hazards associated with the complex mixture of plastic and accumulated pollutants are largely unknown. Here, we show that fish, exposed to a mixture of polyethylene with chemical pollutants sorbed from the marine environment, bioaccumulate these chemical pollutants and suffer liver toxicity and pathology. Fish fed virgin polyethylene fragments also show signs of stress, although less severe than fish fed marine polyethylene fragments. We provide baseline information regarding the bioaccumulation of chemicals and associated health effects from plastic ingestion in fish and demonstrate that future assessments should consider the complex mixture of the plastic material and their associated chemical pollutants.
Small plastic detritus, termed 'microplastics', are a widespread and ubiquitous contaminant of marine ecosystems across the globe. Ingestion of microplastics by marine biota, including mussels, worms, fish and seabirds, has been widely reported, but despite their vital ecological role in marine food-webs, the impact of microplastics on zooplankton remains under-researched. Here, we show that microplastics are ingested by, and may impact upon, zooplankton. We used bio-imaging techniques to document ingestion, egestion and adherence of microplastics in a range of zooplankton common to the northeast Atlantic, and employed feeding rate studies to determine the impact of plastic detritus on algal ingestion rates in copepods. Using fluorescence and coherent anti-Stokes Raman scattering (CARS) microscopy we identified that thirteen zooplankton taxa had the capacity to ingest 1.7 - 30.6 µm polystyrene beads, with uptake varying by taxa, life-stage and bead-size. Post-ingestion, copepods egested faecal pellets laden with microplastics. We further observed microplastics adhered to the external carapace and appendages of exposed zooplankton. Exposure of the copepod Centropages typicus to natural assemblages of algae with and without microplastics showed that 7.3 µm microplastics (>4000 ml-1) significantly decreased algal feeding. Our findings imply that marine microplastic debris can negatively impact upon zooplankton function and health.
There are approximately a dozen species of commercially interesting barnacles worldwide, some of which have been cultured on a semi-industrial scale. These species are listed and information is provided with regard to geographical distribution, landings and prices. Traditionally, ‘goose’ barnacles (four species) are considered to be the most important for consumption. World production already stands at 500 tonnes year−1, but this species has not been cultured to date. Some ‘acorn’ barnacles are also consumed (seven species), with harvest levels per species that do not exceed 200 tonnes year−1 and selling prices that can reach US$17/kg. ‘Acorn’ barnacle culture on a world scale is still developing. Nevertheless, production has occurred on a semi-industrial scale; specifically, spat have been collected from the wild and grown in suspended systems. Farming trials have focused on two species of acorn barnacles: Austromegabalanus psittacus (Molina 1782) ‘picoroco’ in Chile and Megabalanus azoricus (Pilsbry 1916) ‘craca’ in Portugal. The large-scale production of these crustaceans will depend on the optimization of spat collection from the wild and/or the parallel development of mass production technologies for larvae (hatcheries). In addition, further development will be achieved by opening up new markets for commercialization.
Since the mass production of plastics began in the 1940s, microplastic contamination of the marine environment has been a growing problem. Here, a review of the literature has been conducted with the following objectives: (1) to summarise the properties, nomenclature and sources of microplastics; (2) to discuss the routes by which microplastics enter the marine environment; (3) to evaluate the methods by which microplastics are detected in the marine environment; (4) to assess spatial and temporal trends of microplastic abundance; and (5) to discuss the environmental impact of microplastics. Microplastics are both abundant and widespread within the marine environment, found in their highest concentrations along coastlines and within mid-ocean gyres. Ingestion of microplastics has been demonstrated in a range of marine organisms, a process which may facilitate the transfer of chemical additives or hydrophobic waterborne pollutants to biota. We conclude by highlighting key future research areas for scientists and policymakers.
Silver nanoparticles (Ag NPs) are becoming increasingly prevalent in consumer products as antibacterial agents. The increased use of Ag NP-enhanced products may lead to an increase in toxic levels of environmental silver, but regulatory control over the use or disposal of such products is lagging due to insufficient assessment on the toxicology of Ag NPs and their rate of release into the environment. In this article we discuss recent research on the transport, activity and fate of Ag NPs at the cellular and organismic level, in conjunction with traditional and recently established methods of nanoparticle characterization. We include several proposed mechanisms of cytotoxicity based on such studies, as well as new opportunities for investigating the uptake and fate of Ag NPs in living systems.
Measurements of microplastics in biota and abiotic matrices are key elements of exposure and risk assessments for this emerging environmental pollutant. We investigated the abundance of microplastics in field-collected biota, sediment and water. An improved sediment extraction method, based on density separation was developed. For analysis of microplastics in biota we found that an adapted enzymatic digestion protocol using proteinase K performed best, with a 97% recovery of spiked plastic particles and no observed degradation effects on the plastics in subsequent Raman analysis. Field analysis revealed that 8 of 9 tested invertebrate species from the North Sea and 68% of analyzed individuals of brown trout (Salmo trutta) from the Swedish West Coast had microplastics in them. Based on the number of plastic particles per kg d.w. the microplastic concentrations found in mussels were approximately a thousand-fold higher compared to those in sediment and surface water samples from the same location.
Marine microscopic plastic (microplastic) debris is a modern societal issue, illustrating the challenge of balancing the convenience of plastic in daily life with the prospect of causing ecological harm by careless disposal. Here we develop the concept of microplastic as a complex, dynamic mixture of polymers and additives, to which organic material and contaminants can successively bind to form an ‘ecocorona’, increasing the density and surface charge of particles and changing their bioavailability and toxicity. Chronic exposure to microplastic is rarely lethal, but can adversely affect individual animals, reducing feeding and depleting energy stores, with knock-on effects for fecundity and growth. We explore the extent to which ecological processes could be impacted, including altered behaviours, bioturbation and impacts on carbon flux to the deep ocean. We discuss how microplastic compares with other anthropogenic pollutants in terms of ecological risk, and consider the role of science and society in tackling this global issue in the future.
Chemical fixation of living cells for microscopy is commonly achieved by crosslinking of intracellular proteins with dialdehydes prior to examination. We herein report a photocleavable protecting group for glutaraldehyde that results in a light-triggered and membrane-permeable fixative, which is nontoxic prior to photocleavage. Lipophilic ester groups allow for diffusion across the cell membrane and intracellular accumulation after enzymatic hydrolysis. Irradiation with UV light releases glutaraldehyde. The in situ generated fixative crosslinks intracellular proteins and preserves and stabilizes the cell so that it is ready for microscopy. In contrast to conventional glutaraldehyde fixation, tissue autofluorescence does not increase after fixation. Caged glutaraldehyde may in future enable functional experiments on living cells under a light microscope in which events of interest can be stopped in spatially confined volumes at defined time points. Samples with individually stopped events could then later be analyzed in ultrastructural studies.
Chemical fixation of living cells for microscopy is commonly achieved by crosslinking of intracellular proteins with dialdehydes prior to examination. We herein report a photocleavable protecting group for glutaraldehyde that results in a light-triggered and membrane-permeable fixative, which is nontoxic prior to photocleavage. Lipophilic ester groups allow for diffusion across the cell membrane and intracellular accumulation after enzymatic hydrolysis. Irradiation with UV light releases glutaraldehyde. The in situ generated fixative crosslinks intracellular proteins and preserves and stabilizes the cell so that it is ready for microscopy. In contrast to conventional glutaraldehyde fixation, tissue autofluorescence does not increase after fixation. Caged glutaraldehyde may in future enable functional experiments on living cells under a light microscope in which events of interest can be stopped in spatially confined volumes at defined time points. Samples with individually stopped events could then later be analyzed in ultrastructural studies.
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The concentration, distribution sources and fate of microplastics in the global marine environment were discussed, so also was the impact of microplastics on a wide range of marine biota.
A need exists for appropriate tools to evaluate risk and monitor potential effects of contaminants in tropical marine environments, as currently impact assessments are conducted by non-representative approaches. Here, a novel bioassay is presented that allows for the estimation of the chronic toxicity of contaminants in receiving tropical marine environments. The bioassay is conducted using planktonic larvae of the barnacle Amphibalanus amphitrite and is targeted at generating environmentally relevant, chronic toxicity data for water quality guideline derivation or compliance testing. The developmental endpoint demonstrated a consistently high control performance, validated through the use of copper as, a reference toxicant. In addition, the biological effects of aluminium, gallium and molybdenum were assessed. The endpoint expressed high sensitivity to copper and moderate sensitivity to aluminium, whereas gallium and molybdenum exhibited no discernible effects, even at high concentrations, providing valuable information on the toxicity of these elements in tropical marine waters. Crown Copyright
A need exists for appropriate tools to evaluate risk and monitor potential effects of contaminants in tropical marine environments, as currently impact assessments are conducted by non-representative approaches. Here, a novel bioassay is presented that allows for the estimation of the chronic toxicity of contaminants in receiving tropical marine environments. The bioassay is conducted using planktonic larvae of the barnacle Amphibalanus amphitrite and is targeted at generating environmentally relevant, chronic toxicity data for water quality guideline derivation or compliance testing. The developmental endpoint demonstrated a consistently high control performance, validated through the use of copper as a reference toxicant. In addition, the biological effects of aluminium, gallium and molybdenum were assessed. The endpoint expressed high sensitivity to copper and moderate sensitivity to aluminium, whereas gallium and molybdenum exhibited no discernible effects, even at high concentrations, providing valuable information on the toxicity of these elements in tropical marine waters.
Speed, resolution and sensitivity of today's fluorescence bioimaging can be drastically improved by fluorescent nanoparticles (NPs) that are many-fold brighter than organic dyes and fluorescent proteins. While the field is currently dominated by inorganic NPs, notably quantum dots (QDs), fluorescent polymer NPs encapsulating large quantities of dyes (dye-loaded NPs) have emerged recently as an attractive alternative. These new nanomaterials, inspired from the fields of polymeric drug delivery vehicles and advanced fluorophores, can combine superior brightness with biodegradability and low toxicity. Here, we describe the strategies for synthesis of dye-loaded polymer NPs by emulsion polymerization and assembly of pre-formed polymers. Superior brightness requires strong dye loading without aggregation-caused quenching (ACQ). Only recently several strategies of dye design were proposed to overcome ACQ in polymer NPs: aggregation induced emission (AIE), dye modification with bulky side groups and use of bulky hydrophobic counterions. The resulting NPs now surpass the brightness of QDs by ≈10-fold for a comparable size, and have started reaching the level of the brightest conjugated polymer NPs. Other properties, notably photostability, color, blinking, as well as particle size and surface chemistry are also systematically analyzed. Finally, major and emerging applications of dye-loaded NPs for in vitro and in vivo imaging are reviewed.
Each year, millions of metric tons of the plastic produced for food packaging, personal care products, fishing gear, and other human activities end up in lakes, rivers, and the ocean. The breakdown of these primary plastics in the environment results in microplastics, small fragments of plastic typically less than 1-5 mm in size. These synthetic particles have been detected in all of the world's oceans and also in many freshwater systems, accumulating in sediment, on shorelines, suspended in surface waters, and being ingested by plankton, fish, birds, and marine mammals. While the occurrence of plastics in surface waters has been surveyed in a number of studies, the impacts of microplastics on marine organisms are still being elucidated. This highlight features three recent publications that explore the interactions of microplastics with planktonic organisms to clarify the effects of these pollutants on some of the ocean's smallest and most important inhabitants.
Yes, we are eating plastic-ingesting fish. A baseline assessment of plastic pellet ingestion by two species of important edible fish caught along the eastern coast of Brazil is described. The rate of plastic ingestion by king mackerel (Scomberomorus cavalla) was quite high (62.5%), followed by the Brazilian sharpnose shark (Rhizoprionodon lalandii, 33%). From 2 to 6 plastic resin pellets were encountered in the stomachs of each fish, with sizes of from 1 to 5 mm, and with colors ranging from clear to white and yellowish. Ecological and health-related implications are discussed and the potential for transferring these materials through the food-chain are addressed. Further research will be needed of other species harvested for human consumption.
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.
The impact of silver nanoparticles (AgNPs) on aquatic algae has largely been studied with model species that possess a rigid cell wall. Here, we explored the interactions of AgNPs with Euglena gracilis, a green alga having no cell wall but a pellicle. The toxicity and silver uptake upon 1–2 h of exposure to various concentrations of AgNO3 and AgNPs, having a mean size of 47 nm measured in the exposure medium, were examined. The photosynthetic yield decreased in a concentration-dependent manner and AgNPs were less toxic than AgNO3 based on the total silver added. The cell morphology was significantly altered by AgNPs and AgNO3. The damaging effects of AgNPs on the photosynthesis and morphology were completely prevented by cysteine, suggesting that the toxicity of AgNPs was mediated by dissolved Ag. Indeed, the maximal quantity of cell-associated silver was higher upon exposure to AgNPs compared to that upon AgNO3 exposure, amounting to 5.1 × 10−4 mol Lcell−1 and 1.4 × 10−4 mol Lcell−1 for AgNPs and AgNO3, respectively. However, the difference was not caused by the cellular uptake of AgNPs, but by the strong sorption of AgNPs onto the pellicle.
Nano-sized polymers as polystyrene (PS) constitute one of the main challenges for marine ecosystems, since they can distribute along the whole water column affecting planktonic species and consequently disrupting the energy flow of marine ecosystems. Nowadays very little knowledge is available on the impact of nano-sized plastics on marine organisms. Therefore, the present study aims to evaluate the effects of 40nm anionic carboxylated (PS-COOH) and 50nm cationic amino (PS-NH2) polystyrene nanoparticles (PS NPs) on brine shrimp Artemia franciscana larvae. No signs of mortality were observed at 48h of exposure for both PS NPs at naplius stage but several sub-lethal effects were evident. PS-COOH (5-100μg/ml) resulted massively sequestered inside the gut lumen of larvae (48h) probably limiting food intake. Some of them were lately excreted as fecal pellets but not a full release was observed. Likewise, PS-NH2 (5-100µg/ml) accumulated in larvae (48h) but also adsorbed at the surface of sensorial antennules and appendages probably hampering larvae motility. In addition, larvae exposed to PS-NH2 undergo multiple molting events during 48h of exposure compared to controls. The activation of a defense mechanism based on a physiological process able to release toxic cationic NPs (PS-NH2) from the body can be hypothesized. The general observed accumulation of PS NPs within the gut during the 48h of exposure indicates a continuous bioavailability of nano-sized PS for planktonic species as well as a potential transfer along the trophic web. Therefore, nano-sized PS might be able to impair food uptake (feeding), behavior (motility) and physiology (multiple molting) of brine shrimp larvae with consequences not only at organism and population level but on the overall ecosystem based on the key role of zooplankton on marine food webs.
Advances in the use of poly (methyl methacrylate) (PMMA) have opened up a wide range of applications in the field of nanotechnology. The knowledge of the properties of PMMA has contributed a lot to the recent boosts in the synthesis, modification, and applications of the polymer. However, there is a need to condense these developments in the form of an article for better understanding and easy access. This review highlights the fundamental physical properties of PMMA, coupled with experimental evidence of its essential chemistry, such as solubility, hydrolysis, grafting, combustion reactions, reactions with amines, and thermal decomposition. The recent developments in the applications of PMMA in biomedical, optical, solar, sensors, battery electrolytes, nanotechnology, viscosity, pneumatic actuation, molecular separations, and polymer conductivity were also revealed.
Plastic debris in the marine environment is widely documented, but the quantity of plastic entering the ocean from waste generated on land is unknown. By linking worldwide data on solid waste, population density, and economic status, we estimated the mass of land-based plastic waste entering the ocean. We calculate that 275 million metric tons (MT) of plastic waste was generated in 192 coastal countries in 2010, with 4.8 to 12.7 million MT entering the ocean. Population size and the quality of waste management systems largely determine which countries contribute the greatest mass of uncaptured waste available to become plastic marine debris. Without waste management infrastructure improvements, the cumulative quantity of plastic waste available to enter the ocean from land is predicted to increase by an order of magnitude by 2025.
Copyright © 2015, American Association for the Advancement of Science.
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.