Search

Heavy metals that are adhered to the surfaces of microplastics in the natural marine environment pose potential threats to marine life. However, little is known about their adsorption mechanisms and composite risks. This study collected seawater, suspended particulate matter (SPM), plankton, and microplastic samples from the waters surrounding Hong Kong, established a method for analyzing 13 heavy metals in the plastisphere, and explored the extrinsic and intrinsic sources of the heavy metals by analyzing natural matrices (seawater, SPM, and plankton) and anthropogenic plastics. We found that heavy metals in the plastisphere were significantly affected by the surrounding matrices, as indicated by its positive correlations with the heavy metals in SPM and plankton at most of the sampling sites. Heavy metals in plankton usually occurred as traces of oxides such as As2O3 and ZnO. The partition coefficients of the studied heavy metals between seawater and the plastisphere were identical to those between the SPM and the plastisphere. No correlations were found between the concentrations of heavy metals in the plastisphere and the heavy metal concentrations, masses, quantities, or surface areas of the microplastics, although some polymer types contained extremely high Cd (676 mg/kg), Pb (1,742 mg/kg), and Zn (1,712 mg/kg) concentrations. Only the Cr, Cu, and Ni concentrations were positively correlated with the specific surface area of the microplastics. A cluster analysis showed that Cr, Cu, and Ni were derived from anthropogenic sources, indicating that adventive heavy metals could be adsorbed by plastics with large specific surface areas. We also established a new composite risk assessment method for heavy metals and microplastics that leverages the specific surface areas of microplastics. The assessment results showed that Cd from Tolo Harbor had a strong ecological risk, while As and Cd from the eastern waters off Hong Kong had moderate composite ecological risks.

Microplastics (MPs) are emerging persistent contaminants in the terrestrial subsurface, and evidence has emerged for significant effects of MPs on the biological and ecosystem functions of soils. Main MP sources include land spreading of sewage sludge and biowaste composts, plastic mulching film used in horticultural fields, waste water irrigation and leachate from the landfills, among others. This updated state-of-the-art review paper describes recent experimental and numerical research and developments in understanding the accumulation and fate and effects of MPs in the soil environment (focusing on their storage, degradation, transportation, leaching to groundwater etc.), followed by mitigation and bioremediation measures, including MP-eating soil bacteria and fungi and the best management practices for reducing MP pollution of soil. Other areas covered are the combined effects of MPs and various other environmental contaminants (heavy metals, organic pollutants and antibiotics) in soil ecosystems and the standardisation of methods for detection, quantification and characterisation of MPs in soils, which is critical for MP research. The paper concludes by identifying knowledge gaps and presents recommendations on prioritised research needs.

Environmental contamination is of global concern. Lamprey are scientifically, ecologically, culturally, and economically important fishes. Our study represents the first synthesis ever on environmental contamination in lamprey. Objectives of this study include: (1) evaluate lethal and sublethal effects of environmental contaminants on lamprey, thereby providing insight into the potential for environmental contaminants to affect lamprey abundance, (2) highlight the unique characteristics of contaminant accumulation in lamprey, (3) determine whether spatial and temporal trends observed in contaminant concentrations of other top predators of aquatic food webs are reflected in the spatial and temporal trends of contaminant concentrations of lamprey, (4) identify key environmental contaminants affecting consumption advisories for people eating lamprey, and (5) identify important gaps in our knowledge of environmental contamination in lamprey. The geographic scope of this synthesis is worldwide. We conclude that, in general, the environmental contaminant concentrations that have been experienced by lamprey in the wild appear to be nonlethal to lamprey. However, environmental contaminants exert sublethal effects on lamprey. Sea lamprey (Petromyzon marinus) and Pacific lamprey (Entosphenus tridentatus) are relatively high in total mercury (Hg) concentration compared with other fishes. Compared with other top predators, lamprey are relatively low in polychlorinated biphenyl (PCB) concentration and concentrations of organochlorine pesticides. We also conclude that regulations on the use of PCBs, beginning in the 1970s, were effective in dramatically reducing PCB concentration in lamprey since the 1970s. Emerging contaminants, such as pharmaceuticals, microplastics, and per- and polyfluorinated alkyl substances (PFAS), have yet to be studied in lamprey.

Scientists have demonstrated the presence of microplastics (MPs) in tap and bottled water at various locations. On a global scale, there is still very limited information on MP pollution in drinking water. There are huge differences in reported MP concentration, but no clear conclusion can be drawn if MP content is higher in tap or bottled water. Up to date, it is not clear if these discrepancies arise from differences between the examined systems or from differences in quantification limits, the accuracy of the applied analytical techniques, or contamination during sampling, processing, and analysis. Furthermore, information on MP uptake and fate gained through animal and cell toxicity studies is very limited. To define a limit of tolerance for plastic pollution in drinking water, comparable data resulting from quality assured and controlled methods and more information on the potential uptake and fate of MPs in the human body are still needed.

Microplastic (MP) pollution has been found in the Southern Ocean surrounding Antarctica, but many local regions within this vast area remain uninvestigated. The remote Weddell Sea contributes to the global thermohaline circulation, and one of the two Antarctic gyres is located in that region. In the present study, we evaluate MP (>300 μm) concentration and composition in surface (n = 34) and subsurface water samples (n = 79, ∼11.2 m depth) of the Weddell Sea. All putative MP were analyzed by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. MP was found in 65% of surface and 11.4% of subsurface samples, with mean (±standard deviation (SD)) concentrations of 0.01 (±0.01 SD) MP m-3 and 0.04 (±0.1 SD) MP m-3, respectively, being within the range of previously reported values for regions south of the Polar Front. Additionally, we aimed to determine whether identified paint fragments (n = 394) derive from the research vessel. Environmentally sampled fragments (n = 101) with similar ATR-FTIR spectra to reference paints from the research vessel and fresh paint references generated in the laboratory were further subjected to micro-X-ray fluorescence spectroscopy (μXRF) to compare their elemental composition. This revealed that 45.5% of all recovered MP derived from vessel-induced contamination. However, 11% of the measured fragments could be distinguished from the reference paints via their elemental composition. This study demonstrates that differentiation based purely on visual characteristics and FTIR spectroscopy might not be sufficient for accurately determining sample contamination sources.

Microplastics (MPs) are ubiquitous in the environment and are infiltrating the food chain, causing potential risks to living beings. However, current methods of MP removal from an aqueous environme...

Plastics provide tremendous societal benefits and are an indispensable part of our lives. However, fragmented plastics or those intentionally manufactured in small sizes (microplastics and nanoplastics) are of concern because they can infiltrate soils and enter the human food chain through trophic transfer. The pathophysiological impacts of micro- and nanoplastics in humans are not characterized, but their effects in terrestrial mammals may help elucidate their potential effects in humans. Rodent studies have demonstrated that micro- and nanoplastics can breach the intestinal barrier, accumulate in various organs, cause gut dysbosis, decrease mucus secretion, induce metabolic alterations, and cause neurotoxicity, among other pathophysiologic effects. Larger mammals such as rabbits can also absorb microplastics orally. In farm animals such as chickens, microplastics have been detected in the gut, thereby raising food safety concerns. This review mostly focuses on studies conducted to assess effects of micro- and nanoplastic exposure through food and water in terrestrial mammals and farm animals including rodents, rabbits, and chickens; identifies main knowledge gaps; and provides recommendations for further research to understand foodborne micro- and nanoplastic toxicity in humans.

Nano-/microplastics (NP) is a human-made emerging contaminant with worldwide occurrence. The small size (below one micrometer), the different chemical nature and the persistence make NP to potential hazards with suspect probability of tissue penetration and inflammation or as accumulator for toxins. A strategy to stop the spill of novel NP is the remediation from waste water or rivers as prominent distributors. We have developed core–shell superparamagnetic iron oxide nanoparticles (SPIONs) that attract NP and glue them to larger agglomerates which then can be removed from water by applying an external magnetic field. The shell molecules provide two interaction motifs towards NP. The tuned surface potential of the functionalized SPIONs attract complementary charged NP efficiently and the n-alkyl chain is dedicated to preferential interaction towards organic NP rather than inorganic particles. Structural analytics and molecular dynamics simulation support the proposed concept. Systematic remediation experiments with different NP (chemical structures, sizes and mixtures), from different waters – including river water – and with different SPION core materials indicate a universal validity of the concept, with best remediation performance for mixed NP. We suggest a method for broadband remediation of various NP with simple materials and processes, which both have the potential to be up-scaled.

Microplastics (MPs) pollution in the water environment is recognized as an important environmental risk. Among the diverse sources of MPs pollution, road dust is a major contributor via stormwater runoff. Roaddust mainly originates from degradation of vehicle tyres, road marking paints, polymer-modified bitumen and the broken plastics on the surface of the road. The objective of this study is to provide a comprehensive understanding of the fate and control of MPs in the open water environment. This review critically discusses the characteristics and pathways of road dust-associated MPs in stormwater and common stormwater treatment processes used for removing MPs, and provides insight into the technical challenges of these technologies. Constructed wetland is widely used for stormwater management; however, it is found that this process is only removing 28 % MPs as they usually remain suspended or settle down very slowly in the sedimentation basin of constructed wetlands. This is because of the low density of MP particles as well as the low retention time of the wetland. Thus, untreated stormwater, rich in MPs, is released into open waterbodies. This study concludes by providing an outlook of the future opportunities of installing membrane- or flotation-based technologies in the outlet of the constructed wetland for removing 90–95 % MPs and other remaining contaminants. Such a process can produce clean water either for use in households, for sanitation, and for industrial and agricultural usage, or alternatively, for safe discharge into open waterways.

Microplastics (MPs) have been detected in drinking water and raw water sources. Therefore, it is important to know the performance of drinking water treatment process. The rapid sand filter (RSF) is one of the water treatments that can be an alternative treatment in removing MPs after several configuration processes (pre-sedimentation, coagulation-flocculation, and sedimentation). This study aims to determine the effectiveness of RSF to remove MPs. The artificial samples were made from plastics bags and tyre flakes, with sizes from 10 μm to more than 500 μm. Bentonite was added to represent turbidity in the water. The average removal efficiency of plastics flakes before entering the filter was 50.48% (using bentonite) and 47.78% (without bentonite). Overall, the removal efficiency for the tyre flakes was 90.72% (using bentonite) and 93.03% (without bentonite). The filtration used in this study was varied between 4 and 10 m/h. Removal efficiency using RSF for plastic flakes on which the Effective Size (ES) filter media 0.39 mm was 97.7% and on which ES 0.68 mm was 94.3%. Meanwhile, the removal efficiency of the tyre flakes for ES 0.39 mm were 90.6% and ES 0.68 mm was 85.2%. However, in this study, RSF mostly removed MPs particles greater than 200 μm in size. HIGHLIGHTS Mostly MPs >= 200 μm can be removed by using a conventional rapid sand filter.; Increased turbidity will not increase the efficiency of MPs removal.; Part of the MPs can also be removed in coagulation and flocculation.; Size of MPs is important for the surface screening mechanism.

Millions of tons of microplastics (MPs) enter the wastewater collection systems every day and interact with raw sewage. In addition to MPs, varieties of organic and inorganic fines from urban effluents release into the sewer system and provide suitable surfaces for adsorption. To better understand the quantitative assessment of MPs sorption in wastewater and the role of fines, batch reactor experiments were performed using synthetic wastewater solutions containing organic, inorganic, and mixed organic–inorganic fines, and the results compared to a solution without fines. The MPs were two types of clean polypropylene (PP) particles, isotactic (iPP) and atactic (aPP). The results showed in all applied solutions the adsorption of pollutants was higher for the aPP averaging 1.3 mg/g compared with 0.5 mg/g for iPP, indicating that the adsorption varies with the type of polymer and surface properties. Further experiments also revealed a decrease in the sorption values of MPs for solutions containing inorganic fines, measured as the partition coefficient (Kd) and adsorbed concentration at equilibrium (qe). The result of the measured reference conductivity (к25) of the solutions for the same tests showed similar trends indicating that the magnitude of pollution adsorption onto MPs surfaces is controlled by the surface charge potential of the fine particles. The relationship between the qualitative assessments of ion removal, measured in terms of к25, and their quantitative assessment of adsorption values in terms of Kd in several identical tests, verifying that the conductivity of the solution was modified after adsorption of wastewater constituents onto the MPs.

In this research, the fate and removal of microplastics (MPs) entering and leaving a wastewater treatment plant (WWTP) was investigated. Additionally, application of the microfiltration membrane technique for MPs removal was evaluated. In the first phase, the quantity, type and size of the MPs were studied from three different points of the WWTP. The results showed that the average amount of MPs entering into the WWTP, accumulated in the sludge matrix and discharged from the effluent were 206, 183 and 94 MP/L, respectively. The MPs were observed mainly in the forms of fibers, pellets, and fragments, with a proportion of 35%, 39%, 22%, and 34%, 22%, 38%, and 31%, 39%, 37.7% in the influent, effluent and sludge of the WWTP, respectively. It should be noted, a minor amount of foam (2%) and film (0.3%) was also observed. The particle size distribution of the MPs in the effluent of the system was almost identical (6–14% for 1–5,000 μm), while the influent mostly contained particles within 1–100 μm (above 26%) with other particle sizes within 100–5,000 μm (8–17%). Particle size within a range of 500–5,000 μm was abundant in the sludge. In the second phase, a micro-filtration (MF) membrane with a pore size of 0.1 μm was applied to eliminate the MPs from the WWTP effluent. It was observed the application of the MF membrane technique could achieve MPs removal efficiency up to 98% in the effluent of the system. Highlights The fate of microplastics (MPs) in the wastewater treatment plant (WWTP) was evaluated.; The most abundant MPs were fibers, pellets, and fragments in the in/effluent and sludge of WWTP.; This investigation provides a preliminary insight for management of MPs in WWTPs.; An advanced tertiary treatment process was applied for MPs removal.; The MPs particles were reduced up to 98% by application of the microfiltration membrane (MBR).

Microplastics are a widespread contaminant found not only in various natural habitats but also in drinking waters. With spectroscopic methods, the polymer type, number, size, and size distribution as well as the shape of microplastic particles in waters can be determined, which is of great relevance to toxicological studies. Methods used in studies so far show a huge diversity regarding experimental setups and often a lack of certain quality assurance aspects. To overcome these problems, this critical review and consensus paper of 12 European analytical laboratories and institutions, dealing with microplastic particle identification and quantification with spectroscopic methods, gives guidance toward harmonized microplastic particle analysis in clean waters. The aims of this paper are to (i) improve the reliability of microplastic analysis, (ii) facilitate and improve the planning of sample preparation and microplastic detection, and (iii) provide a better understanding regarding the evaluation of already existing studies. With these aims, we hope to make an important step toward harmonization of microplastic particle analysis in clean water samples and, thus, allow the comparability of results obtained in different studies by using similar or harmonized methods. Clean water samples, for the purpose of this paper, are considered to comprise all water samples with low matrix content, in particular drinking, tap, and bottled water, but also other water types such as clean freshwater., B. E. Oßmann thanks the Bavarian State Ministry of the Environment and Consumer Protection for funding the projects “Detection of microplastics in selected foods” and “Expansion of the analytics of microplastics in food.” S. Lacorte acknowledges funding from the Ministry of Science and Innovation of Spain (project PID2019-105732GB-C21). J. Weisser, K. Glas, T. Hofmann, N. P. Ivleva, and E. von der Esch receive funding from the Bavarian Research Foundation (Bayerische Forschungsstiftung (BFS), AZ-1258-16 (“MiPAq”). N. P. Ivleva thanks the Federal Ministry of Education and Research (Bundesministerium für Bildung und Forschung (BMBF), projects 02WPL1443A “SubμTrack” and 03F0851B “HOTMIC”) for financial support. D. Fischer and F. Fischer acknowledge funding from the projects MicroCatch_Balt, PLASTRAT, PLAWES by the BMBF in the call “Plastics in the environment,” as well as from the BONUS BLUE BALTIC project MICROPOLL, which has received funding from BONUS (Art 185), funded jointly by the EU and the BMBF. N. Zumbülte and C. S. Witzig acknowledge funding by the BMBF of the project “MicBin.”

Microplastics (MPs) have recently become a controversial issue, mainly due to their eco-toxicological effects on aquatic environments. Although a typical wastewater treatment plant (WWTP) removes a large number of MPs from the wastewaters, final effluents are yet considered to be the primary sources of MP contaminations into the environment. Hence, there should be a tertiary treatment called advanced wastewater treatment technology for efficient MP removal. In the current research, Al-based and Fe-based coagulants were used in a dissolved air flotation (DAF) cell as an advanced wastewater treatment technology to remove polyethylene (PE) MPs from greywater, which is one of the most predominant types of MPs found in the greywater. PE reduction up to 96.10 % and 70.56 % were observed for Al- and Fe-based coagulants, respectively. The operative parameters, including pressure, pH, coagulant dosage, and water flow rate into the flotation cell, were identified. The experimental design was developed using Design-Expert software to investigate and maximize the PE removal efficiency. As a result, some sufficiently accurate statistical models were proposed to obtain the optimum quantities of the respective factors. It was determined that the most effective removal was achieved with 5.95 bar saturation pressure, pH 6, 14.46 mg/L coagulant concentration, and 680.5 mL/min water flow rate into the flotation cell using AlCl3·6H2O as the coagulant.

Benthic communities contain some of the most threatened organisms in aquatic habitats due to different anthropogenic pressures. The high abundance of microplastics in sediments will continue to increase in the future, further increasing the probability of interactions between macroinvertebrates and microplastics. In the present study, a benthic community in a relatively pristine shallow pond was exposed either to an environmentally relevant high concentration of a microplastic mixture of 80 g m

Microplastic contamination is ubiquitous in aquatic and terrestrial environments, found in water, sediments, within organisms and in the atmosphere and the biological effects on animal and plant life have been extensively investigated in recent years. There is growing evidence that humans are exposed to microplastics via ingestion of food and drink and through inhalation. Despite the prevalence of contamination, there has been limited research on the effects of microplastics on human health and most studies, to date, analyse the effects on model organisms with the likely impacts on human health being inferred by extrapolation. This review summarises the latest findings in the field with respect to the prevalence of microplastics in the human-environment, to what extent they might enter and persist in the body, and what effect, if any, they are likely to have on human health. Whilst definitive evidence linking microplastic consumption to human health is currently lacking, results from correlative studies in people exposed to high concentrations of microplastics, model animal and cell culture experiments, suggest that effects of microplastics could include provoking immune and stress responses and inducing reproductive and developmental toxicity. Further research is required to explore the potential implications of this recent contaminant in our environment in more rigorous clinical studies.

The widespread presence of microplastics has caused significant concerns on their potential effects on marine ecosystems. Microplastics are classified as plastic products of less than 5 mm in size and are known to be one of the most dangerous aquatic debris to marine species. Sea cucumbers are deposit feeders living in sediment regions and benthic zone that may collect microplastics in low-energy environments. This research aims to evaluate the types of microplastic isolated from the intestine of Stichopus horrens in Malaysia. This species is selected because it is mainly found in this island. Pulau Pangkor is one of the leading tourism destinations on the small islands is facing increasing numbers of tourists and development and it is useful for sustainable study. A total of 20 S. horrens samples collected from Pulau Pangkor, Malaysia were dissected, and their intestines were collected for digestion. Microplastics were extracted using NaOH and filtered using filter paper. Microplastic identification was conducted on the based of the physical characteristics (colour, shape, size) and chemical characterisation was evaluated using FTIR for polymer functional groups. A total of 1446 unit of microplastics were found in S. horrens. Among various types and colours, fibre (90%) and black (59%) were dominant amongst the various particles identified. The majority of microplastics sizes were 0.51 μm and 1-2 μm. Two polymer materials were identified, namely polyethylene and poly(methyl methacrylate). As a conclusion, the findings of the study will serve as primary data for pollution indicators in respective islands. The microplastics could impact the immune system and upset gut's balance of human.

Nanoplastics (NPs) have showed hotspot of discussion in recent years due to their impact in environment as a futuristic major pollutant in water, soil and air. In this correspondence review on the occurrence of nanoplastics and its effect at the environment as a waste have been overviewed and assimilated. It has the direct or indirect effect on aquatic and terrestrial geographical living beings due to its toxicity. The review revealed the major lacking in the field of analysis, database of contaminant quantity and legislative support to essential eradication on the existing imminent pollutant effects. A brief discussion about properties and characters of nanoplastics has been done. The environment exposed with macroplastics, microplastics and nanoplastics has abundantly contaminated the ecosystem surrounding it. Recent studies reveal that the major health effect by nanosize particles has mainly induced toxicity to the aquatic and terrestrial animals when compared to microsize particles and macrosize particles. The drastic effects and its toxicity in living ecosystem due to nanoplastics have been shown. The occurring waste is supposed to manage from environment by treating before entering into environment. The degradation methods for treatment of nanoplastics have been discussed in this review work.

Microplastic pollution is ubiquitous in the marine environment and the consumption of shellfish containing microplastics may pose a risk to human health. This study investigated the occurrence and characteristics of microplastics in three commonly consumed shellfish in the coastal region of Jiangsu Province, China. The average abundance of microplastics in shellfish varied from 0.33 to 9.33 items/individual (0.06-0.92 items/g, wet weight of soft tissue). Microplastic abundance in Jiangsu was relatively low compared to studies from other regions of China and worldwide. Synthetic fibers (66.20%) were predominant and included rayon (34.84%) and polyester (23.23%), indicating that the majority of particles originated from the discharge of clothing fibers in domestic sewage. Transparent (66.20 %) particles were the most common, particle size was generally less than 500 μm (62.30%), and abundance decreased as the particle size increased. The average annual intake of microplastics by Jiangsu coastal residents via the consumption of common bivalves was estimated to be 1088.64 items/person/year. This study provides data to support ecological and health risk assessments for microplastics in the Jiangsu coastal region.

Nanoparticles (NPs) for delivering chemotherapeutic drugs are now in clinical trials, and cellular uptake of NPs plays an important role in determining the drug delivery efficiency. Herein, we reported that the bioaccumulation and internalization of NPs were governed by the cell cycle. Specifically, we found that the bioaccumulation of NPs was more favored in the G2/M stages, followed by the S and G0/G1 stages. We demonstrated that three key parameters-clathrin-mediated endocytosis capacity, algal cell membrane permeability, and exopolymer substance (EPS) thickness-were critical in the bioaccumulation of NPs during the cell cycling process. Over the 24-h average duration of cell cycle, clathrin-mediated endocytosis capacity was much higher at the S stage than that at the G0/G1 and G2/M stages. Besides, cell membrane permeability was measured to be higher in S and G2/M stages while the lowest in G0/G1 stage. We have also identified the change of EPS thickness during the 24-h cell cycle. Transition from G0/G1 to S and G2/M induced the attenuation in EPS thickness, and the thinnest EPS was found at the end of mitosis. The cell cycle control NPs internalization were further verified by exposing Ag nanoparticles to algae at different cell cycle stages, confirming the important roles of EPS thickness and cell cycle control in the dynamic internalization processes. The present study highlights the important roles of cell cycle controlling the NPs bioaccumulation and internalization, with possible implications in maximizing NPs internalization efficiency while reducing the cost.

he ubiquity of microplastics in aquatic ecosystems has raised concerns over their interaction with biota. However,microplastics research on freshwater species, especially mollusks, is still scarce. We, therefore, investigated the factorsaffecting microplastics ingestion in the freshwater musselDreissena polymorpha. Using polystyrene spheres (5, 10, 45,90μm), we determined the body burden of microplastics in the mussels in relation to 1) exposure and depuration time, 2)body size, 3) food abundance, and 4) microplastic concentrations.D. polymorpharapidly ingested microplastics and ex-creted most particles within 12 h. A few microplastics were retained for up to 1 wk. Smaller individuals had a higher relativebody burden of microplastics than larger individuals. The uptake of microplastics was concentration‐dependent, whereas anadditional food supply (algae) reduced it. We also compared the ingestion of microplastics byD. polymorphawith 2 otherfreshwater species (Anodonta anatina,Sinanodonta woodiana), highlighting that absolute and relative uptake depends onthe species and the size of the mussels. In addition, we determined toxicity of polystyrene fragments (≤63μm,6.4–100 000 p mL–1) and diatomite (natural particle, 100 000 p mL–1)inD. polymorphaafter 1, 3, 7, and 42 d of exposure,investigating clearance rate, energy reserves, and oxidative stress. Despite ingesting large quantities, exposure to poly-styrene fragments only affected the clearance rate ofD. polymorpha. Further, results of the microplastic and diatomiteexposure did not differ significantly. Therefore,D. polymorphais unaffected by or can compensate for polystyrene fragmenttoxicity even at concentrations above current environmental levels.Environ Toxicol Chem2021;40:2247–2260. © 2021 TheAuthors.Environmental Toxicology and Chemistrypublished by Wiley Periodicals LLC on behalf of SETAC.Keywords:Microplastics; Toxic effects; Mollusk toxicity

Daily use of plastic feeding and water bottles occur widely in China, and they could be sources for release of microplastics (MPs), which threaten the health of Chinese infants and children during daily usage. In this work, we investigated the use of polycarbonate (PC) and polypropylene (PP) for making water bottles (WBs) and polyphenylene sulfone resins (PPSU) for making feeding bottles (FBs), and we found that feeding bottles and water bottles released microparticles in amounts ranging from 53 to 393 particles/mL during 100 opening/closing cycles. The good linear regressions for plots of microparticles released vs. abrasion distance (r2 = 0.811) indicated that thick-necked bottles release more microparticles than thin-necked bottles. The brands and types of bottles (plastic vs. glass) influence microparticle release, and this indicates that high-quality plastic and glass bottles release fewer microparticles and are good for the health of infants and children. In addition to calcium stearate and silicone additives, the identified MPs account for 7.5 to 42.1% of released microparticles with different polymer types, sizes (from 20 to 500 μm) and shapes (cubic, spherical and irregular shapes). Additionally, an average of 1.74 MPs were released from an injection with a single-use plastic injector. Nevertheless, a number of microparticles and nanosized plastics were observed with all samples, suggesting that the health risks of micro- and nanosized particles to humans, especially babies and children, and the environment should be considered seriously. Supplementary Information The online version contains supplementary material available at 10.1007/s11356-021-14939-7.

Microplastic (plastic particles measuring

Growing evidence demonstrated that bioaccumulation of polystyrene nanoplastics (PS-NPs) in various organisms including human beings caused destructive effects on health. Nanoplastics may adversely affect fetal development potentially since they can pass through the placental barrier. However, very little has been known about the embryonic toxicity of polystyrene nanoplastics, especially in embryonic neurulation, the early developmental stage of the fetus, as well as the corresponding mechanisms. In this study, we first observed that 60- or 900-nm PS-NPs (especially 60-nm PS-NPs) could cross mouse placentas and affect developing mice fetuses. To avoid the indirect adverse effects derived from the restricted placenta, we employed early chick embryos as a developmental model to evaluate direct adverse effects of PS-NPs on embryo/fetal development, revealing suppressive effects on embryo development and an increased frequency of congenital abnormalities (especially in the nervous system), including neural tube defects. Thus, we focused on the potential negative effects of PS-NPs on neurulation, the earliest stage of nervous system development. Using caveolin-1 immunofluorescent staining of SH-SY5Y cells exposed to PS-NPs-GFP, we demonstrated that PS-NPs were internalized by SH-SY5Y cells via caveolae-mediated endocytosis. Transmission electron microscopy; LC3B immunofluorescent staining; and Atg7, Atg5, p62 and LC3B western blot results revealed that autophagy was activated in SH-SY5Y cells exposed to PS-NPs. However, PS-NPs were not degraded by the autophagic-lysosomal system given the lack of LAMP1 changes and minimal PS-NPs-GFP and LAMP1 colocalization. Furthermore, the cytoplasmic accumulation of PS-NPs caused faulty apoptotic cell death in SH-SY5Y cells and the developing neural tube as revealed by c-caspase3 immunofluorescent staining. Thus, defective neural tube morphogenesis, as demonstrated by neural tube defects, occurred during embryogenesis in the context of PS-NP exposure.

Environmental context The effects of the presence of polymer additives and polymeric structure on sorption of xenobiotics to microplastics remain unclear. Our results combined data from experimental sorption batch experiments using three environmentally relevant model sorbates with confocal microscopy. This provides clear evidence that both factors play a major role in sorption strength and the underlying sorption process, affecting sorption onto the particle surface and partitioning into the bulk polymer. Abstract Microplastics are particulate contaminants of global concern. Interactions of microplastics with organic contaminants are frequently studied with commercially available polymer materials as surrogates. The influence of the polymer structure (i.e. internal 3D polymer geometry and monomer chain length) and the presence of additives on their interactions with xenobiotics remains unclear. This work investigates sorption of three sorbates of environmental concern to two polyamide (PA) and two polyvinyl chloride (PVC) sorbents of different molecular composition and additive content, respectively. Sorption was studied using complementary data from sorption isotherms and confocal laser-scanning microscopy. The additives in PVC increased sorption affinity owing to an increased sorbent hydrophobicity and a higher void volume within the polymer. Surface area normalisation indicated surface adsorption for unplasticised PVC and absorption for 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH)-plasticised PVC, which were confirmed using confocal laser-scanning microscopy. The strong sorption to PA was mainly driven by hydrogen-bond interactions. The contribution depended on the molecular features of the sorbent and the sorbate. Confocal laser-scanning microscopy showed that PA6 was taking up more sorbate into its bulk polymer matrix than PA12, the two being different in their chemical composition. This difference could be attributed to the higher swelling capability of PA6. The results emphasise that the molecular structure of the polymer and the presence of additives have to be taken into consideration when sorption of organic substances to plastics is investigated.

The ingestion of microplastics (MPs) is well documented for various animals and spherical MPs (beads) in many studies. However, the retention time and egestion of MPs have been examined less, especially for irregular MPs (fragments) which are predominantly found in the environment. Furthermore, the accumulation of such particles in the gastrointestinal tract is likely to determine whether adverse effects are induced. To address this, we investigated if the ingestion and egestion of beads are different to those of fragments in the freshwater shrimp Neocaridina palmata. Therefore, organisms were exposed to 20–20,000 particles L−1 of either polyethylene (PE) beads (41 μm and 87 μm) or polyvinyl chloride (PVC) fragments (−1 of either 41 μm PE and 11 μm polystyrene (PS) beads or the PVC fragments for 24 h, followed by a post-exposure period of 4 h to analyze the excretion of particles. To simulate natural conditions, an additional fragment ingestion study was performed in the presence of food. After each treatment, the shrimps were analyzed for retained or excreted particles. Our results demonstrate that the ingestion of beads and fragments were concentration-dependent. Shrimps egested 59% of beads and 18% of fragments within 4 h. Particle shape did not significantly affect MP ingestion or egestion, but size was a relevant factor. Medium- and small-sized beads were frequently ingested. Furthermore, fragment uptake decreased slightly when co-exposed to food, but was not significantly different to the treatments without food. Finally, the investigations highlight that the assessment of ingestion and egestion rates can help to clarify whether MPs remain in specific organisms and, thereby, become a potential health threat.

Microplastics are discharged into the environment through human activities and are persistent in the environment. With the prevalent use of plastic-based personal protective equipment in the prevention of the spread of the COVID-19 virus, the concentration of microplastics in the environment is envisaged to increase. Potential ecological and health risks emanate from their potential to adsorb and transport toxic chemicals, and ease of absorption into the cells of living organisms and interfering with physiological processes. This review (1) discusses sources and pathways through which microplastics enter the environment, (2) evaluates the fate and behavior of microplastics, (3) discusses microplastics in African aquatic systems, and (4) identifies research gaps and recommends remediation strategies. Importantly, while there is significant microplastics pollution in the aquatic environment, pollution in terrestrial systems are not widely studied. Besides, there is a dearth of information on microplastics in African aquatic systems. The paper recommends that the governments and non-governmental organizations should fund research to address knowledge gaps, which include: (1) the environmental fate of microplastics, (2) conducting toxicological studies under environmentally relevant conditions, (3) investigating toxicity mechanisms to biota, and developing mitigation measures to safeguard human health, and (4) investigating pollutants transported by microplastics. Moreover, regulatory measures, along with the circular economy strategies, may help reduce microplastic pollution.

A summary is presented of the anthropogenic debris recorded up to 2020 in stomachs of marine fishes from New Zealand waters. This material (mainly plastics) was found in the stomachs of 28 species,...

Data Availability Statement: Data, associated metadata, and calculation tools are available from the corresponding author (mark.scrimshaw@brunel.ac.uk). Copyright © 2021 The Authors. Any uncertainty in determining numbers of microplastics in the environment may be a barrier to assessing their impact and may stem from various aspects of methodologies used to quantify them. We undertook a comparison of approaches to quantify and characterize microplastics in 4 personal care products. The aim was not only to determine how many particles were present but to assess any differences due to the methods used. Counting of extracted microplastics was undertaken using particle size analysis, light microscopy, and imaging flow cytometry. Micro–Fourier transform infrared spectroscopy (µ-FTIR) was used to characterize the particles in each product. The mean size distribution of microplastics differed depending on the method employed, and it was apparent that imaging flow cytometry was affected by high background noise that may require staining of plastics to overcome. The application of µ-FTIR confirmed polyethylene as the microplastic in each product. Methodological challenges encountered in the study and the literature have highlighted the need for standardization of methods for determining microplastics.

The goals of this study were to investigate the distribution profiles, sources, and inventory of microplastics in the surface water of the mainstream of the Pearl River (Xijiang River) and its estuary, China, and to assess the potential ecological risks of the microplastics in this subtropical riverine habitat. The results showed that the microplastic abundances of the Humen (HUM, 16.33 ± 0.88 items/L), Zhaoqing (ZQ, 15.33 ± 0.67 items/L), and Hutiaomen (HTM, 14.67 ± 1.33 items/L) sites were significantly higher than those of the other sampling sites, indicating that the microplastics in Xijiang River and its estuary exhibited an unbalanced spatial distribution. The most common microplastic color was transparent and the major shape of the microplastics was fragments. Microplastics with a size of 0.01-0.1 mm were dominant throughout the 16 sampling sites. Polyolefin elastomer (POE, 33.33%), polyethylene terephthalate (PET, 23.81%), and polyurethane acrylate (PUA, 14.29%) were the dominant microplastic polymers. The microplastic abundance co-varied with most of the selected socio-economic indicators, including the population density, urban land area, gross domestic product (GDP), freshwater aquatic products, and freshwater cultivated area, but without significant differences, indicating that there are additional factors affecting the microplastic abundance. The potential risk (i.e., the potential ecological risk, RI; polymer risk index, H; and pollution load index, PLI) posed by the microplastics was higher in HUM, followed by ZQ and HTM, and it was lower for the other sites, suggesting that the main outlets and the biggest city on the Xijiang River contributed more to the high risks of microplastic pollution. Consistent with microplastic abundance distribution profiles, the average potential risk index values of the western river outlets were higher than those of the eastern river outlets and the Xijiang River, implying that the western river outlets had non-negligible potential ecological risks. Our findings deepen the understanding of the risks posed by microplastics and further contribute to microplastic risk management of riverine ecosystems.

Microplastics (MPs) are emerging contaminants that cause diverse impacts on soil ecosystems. As integral members of soil food webs, soil fauna exert key ecological functions such as litter decomposition, nutrient cycling, and energy flow. MPs may damage soil fauna and their ecological functions, posing ecological and health risks. Meanwhile, soil fauna can act on MPs. Hereby, we aim to summarize the interactions between MPs and soil fauna. This article first introduces the source, occurrence and characteristics of MPs in soils, and then highlights the interactions between MPs and soil fauna, particularly earthworms and nematodes. MPs can cause negative impacts on the growth, reproduction, lifespan, and survival of soil fauna, via diverse toxicity mechanisms such as ingestion and bioaccumulation, histopathological damage, oxidative stress, DNA damage, genotoxicity, reproductive toxicity, neurotoxicity, metabolic disorders, and gut microbiota dysbiosis. MPs can also interact with other contaminants to produce combined toxicity to soil fauna. In turn, soil fauna can contribute to the formation and breakdown of MPs, alter the migration of MPs in soil, and even transfer accumulated MPs to higher trophic levels. Finally, given the large knowledge gap regarding the interaction of soil fauna and MPs, several future research priorities are recommended.

The fragmentation of macro- into microplastics (MP) is the main source of MP in the environment. Nevertheless, knowledge about degradation mechanisms, changes in chemical composition, morphology, and residence times is still limited. Here, we present a long-term accelerated weathering study on polystyrene (PS) tensile bars and MP particles using simulated solar radiation and mechanical stress. The degradation process was monitored by gel permeation chromatography (GPC), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), 13C magic-angle spinning (MAS) NMR spectroscopy, tensile testing, and Monte Carlo simulations. We verified that degradation proceeds in two main stages. Stage I is dominated by photooxidation in a near-surface layer. During stage II, microcrack formation and particle rupturing accelerate the degradation. Depending on the ratio and intensity of the applied stress factors, MP degradation kinetics and lifetimes vary dramatically and an increasing amount of small MP fragments with high proportions of carboxyl, peroxide, and keto groups is continuously released into the environment. The enhanced surface area for adsorbing pollutants and forming biofilms modifies the uptake behavior and interaction with organisms together with potential ecological risks. We expect the proposed two-stage model to be valid for predicting the abiotic degradation of other commodity plastics with a carbon-carbon backbone.

The sea urchin Paracentrotus lividus (P. lividus) was exposed to either virgin or biofilm-covered polystyrene microbeads (micro-PS, 45 μm) in order to test the effect of microbial colonization on the uptake, biodistribution, and immune response. The biofilm was dominated by bacteria, as detected by scanning electron microscopy and 16S rRNA sequencing. A higher internalization rate of colonized micro-PS inside sea urchins compared to virgin ones was detected, suggesting a role of the plastisphere in the interaction. Colonized and virgin micro-PS showed the same biodistribution pattern by accumulating mainly in the digestive system with higher levels and faster egestion rates for the colonized. However, a significant increase of catalase and total antioxidant activity was observed only in the digestive system of colonized micro-PS-exposed individuals. Colonized micro-PS also induced a significant decrease in the number of coelomocytes with a significant increase in vibratile cells, compared to control and virgin micro-PS-exposed animals. Moreover, a general time-dependent increase in the red/white amoebocytes ratio and reactive oxygen species and a decrease in nitrogen ones were observed upon exposure to both colonized and virgin micro-PS. Overall, micro-PS colonization clearly affected the uptake and toxicological responses of the Mediterranean sea urchin P. lividus in comparison to virgin micro-PS.

Microplastic (

The extensive research on microplastics (MPs) in the last years has shown that it is not just an environmental problem anymore. As it can also be found in human food, it poses a potential risk for human health and food safety. Especially sea salt, which is produced by the evaporation of seawater, including its microplastic contamination, has been reported with different levels of MP contamination. Therefore, in this preliminary study, we investigated if different solar evaporation methods (traditional, geomembrane, and tunnel) influence the concentration of microplastic particles in sea salt production in Indonesia, one of the countries with the highest estimated level of plastic waste input into the ocean. The results show a significantly higher MP contamination in sea salt produced traditionally compared to the geomembrane and tunnel methods.

Currently, people are paying more and more attention to the interaction between microplastics (MPs) and chemical substances (including metals and organic substances), so it is necessary to understand the relationship between MPs and chemical substances. In this review, we explored (1) MPs may become a source of chemical substances. (2) MPs can also be used as a carrier for attaching pollutants. (3) No matter what role MPs play, MPs and the attached chemical substances will have harmful effects on biological systems. However, because the current research is not deep enough, more experimental areas are needed to explore the interaction mechanism and the principle of toxicity. In addition, laws and policies need to be developed that actively promote and strive to develop biodegradable alternative microplastics to reduce the harm of microplastics and their additives to the environment.

This article presents the evolving challenges and roles of our water resources in this contemporary world. First, water quality issues surrounding water supplies are discussed. Potential pathways to address the water quality challenges are presented, which include technological approaches for minimizing waste and enhancing resource recovery. Focused discussions on emerging global pollutants such as microplastics and PFAS (per- and poly-fluoro alkyl substances) and treatment alternatives are included. Next, the roles of used water (wastewater) in the wake of circular economy and recent outbreaks are discussed. The potential for energy and resource recovery possibilities and the critical role of wastewater treatment plants in controlling the spread of outbreaks are discussed in detail. Finally, perspectives on some of the key developments essential for transforming our water infrastructure, addressing water-centered socio-economic issues and the critical needs of digitalization in water sector operations are presented. HIGHLIGHTS Roles of water and wastewater in circular economy and community resiliency are discussed.; Microplastics and PFAS and emerging issues in water and wastewater industry are discussed.; Critical need for digitalization, data control and infrastructure investment are emphasized.

The marine environment is increasingly polluted by anthropogenic wastes, notably plastic debris. This debris breaks down into smaller pieces, known as microplastics. When consumed by marine organisms, microplastics cause various physiological effects. In this study, we sought to determine a link between ingested microplastics and cytochrome P450-1A (CYP1A) expression in fish liver. To achieve this goal, we collected pinfish from five sites in Lower Laguna Madre (LLM, a large coastal lagoon), analyzed stomach contents, excised liver tissues, and performed immunohistochemical analysis to determine CYP1A expression. Microplastics were not discovered in the stomach/intestine of pinfish, though plastic debris was present at various stages of decomposition within sampling sites. Hepatic CYP1A expression was significantly higher in pinfish collected from four of five sampling sites when compared to fish in laboratory conditions. These results imply that pinfish, as well as other organisms, may be exposed to pollutants other than microplastics in LLM.

Microplastic pollution in soils is an emerging topic in the scientific community, with researchers striving to determine the occurrence and the impact of microplastics on soil health, ecology, and functionality. However, information on the microplastic contamination of soils is limited because of a lack of suitable analytical methods. Because micro‐Fourier‐transform infrared spectroscopy (µ‐FTIR), next to Raman spectroscopy, is one of the few methods that allows the determination of the number, polymer type, shape, and size of microplastic particles, the present study addresses the challenge of purifying soil samples sufficiently to allow a subsequent µ‐FTIR analysis. A combination of freeze‐drying, sieving, density separation, and a sequential enzymatic‐oxidative digestion protocol enables removal of the mineral mass (>99.9% dry wt) and an average reduction of 77% dry weight of the remaining organic fraction. In addition to visual integrity, attenuated total reflectance FTIR, gel permeation chromatography, and differential scanning calorimetry showed that polyamide, polyethylene, polyethylene terephthalate, and polyvinyl chloride in the size range of 100 to 400 µm were not affected by the approach. However, biodegradable polylactic acid showed visible signs of degradation and reduced molecular weight distribution after protease treatment. Nevertheless, the presented purification protocol is a reliable and robust method to purify relatively large soil samples of approximately 250 g dry weight for spectroscopic analysis in microplastic research and has been shown to recover various microplastic fibers and fragments down to a size of 10 µm from natural soil samples. Environ Toxicol Chem 2021;00:1–14. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC., A novel purification sequence for natural soil samples undergoing microplastic analysis. image, Ministry for Environment, Climate Protection and Energy of Baden Württemberg, German Federal Ministry of Education and Research (BMBF) http://dx.doi.org/10.13039/501100002347, German Research Foundation (DFG) http://dx.doi.org/10.13039/501100001659

Microplastics (MPs) have been increasingly identified as a global concern because of their ubiquitous distribution and the threats they pose. MPs embedded in the solid matrix remain an underexplored field compared to MPs in aquatic environments. This review focuses on solid-embedded MPs in a binary system consisting of sewage sludge and agricultural soils, which are interconnected through land application of sewage sludge to agricultural soils. The detection, occurrence, and impacts of MPs were summarized for sewage sludge and agricultural soils. Specifically, the latest techniques for detecting solid-embedded MPs are summarized and compared. The occurrence of MPs is presented from three aspects, i.e., the origin, transformation, and properties. Lastly, the impacts of solid-embedded MPs on sewage sludge treatment processes and the agroecosystem are reviewed. As a cutting-edge overview of the current knowledge, this review proposes key challenges to be further investigated with respect to solid-embedded MPs, including a uniform detection procedure, worldwide monitoring programs, rigorous assessments of potential risks, and mitigation measures through collaborative efforts by related liable parties.

Microplastic contamination poses a global threat to aquatic organisms, yet we know little as to how microplastics may indirectly affect organismal health via their influence on species-species interactions (e.g., host-parasite interactions). This is problematic because microplastic-mediated alterations to host-parasite dynamics could negatively impact individual- population-level health of hosts. Using a larval amphibian (host) and free-living trematode (parasite) model, we asked whether 1) polyester microplastic fibers influence parasite survival; 2) whether polyester microplastic fiber ingestion by amphibians alters amphibian susceptibility to infection; and 3) whether simultaneous exposure of amphibians and trematodes to polyester microplastic fibers influences infection outcomes. Polyester microplastic fibers did not alter trematode survival, nor did their ingestion by amphibians increase amphibian susceptibility to infection. However, when amphibians and trematodes were exposed simultaneously to the fibers, the infection success of the parasite was reduced. Lastly, we conducted a field survey for microfiber contamination across multiple ponds and found microfibers across each of the sampled ponds. Overall, our results contribute to the limited knowledge surrounding the ecological consequences of microplastic contamination. Environ Toxicol Chem 2022;41:869-879. © 2021 SETAC.

Scientists are rushing to study the tiny plastic specks that are in marine animals — and in us. Scientists are rushing to study the tiny plastic specks that are in marine animals — and in us.

The study in microplastics removal using nanomaterials is relatively new and the majority of treatment techniques lies in water treatment plant. This research aims to study an innovative approach to mechanically remove microplastics from polluted water inspired by Fionn Ferreira who won the Google Science Fair in 2019. Experiments are designed and conducted to identify the efficiency of the method with varied oil to nanoparticles ratio. Additionally, possible application of the concept was explored presented as a proof of concept. The technique takes advantage of the relatively low surface tension of oil and immiscible properties in water as an adhesive element between the microplastics and magnetic nanoparticles. Stirring the mixture binds all particle components to the oil medium and then removed from the water using a magnet. Since this is a physical interaction, the technique is not limited to microplastics but other solid particles as well. The results presented in this paper concludes the suggested treatment achieved the highest microplastic extraction percentage at 97.312%. The associated ratio was recorded to be a 1:1 unit volume of oil to nanoparticles. The ratio provides sufficient viscosity and surface tension for ease of microplastics extraction. The novelty of the treatment lies in the reusability of the oiled magnetic nanoparticles as a filter medium. Furthermore, a design inspired by gravity sand filter was presented in this paper as a proof of concept and potential application.

Mismanagement of plastic waste has caused plastic leaking into nature and entering our food chain as microplastics, which may have negative impacts on wildlife and our health. However, data on microplastics in bottled water are still limited, especially in Sarawak, Malaysia. This study aims at investigating the presence of microplastics in the bottled water that manufactured locally. So that the F&B manufacturers and other key stakeholders can take necessary actions to prevent or minimize microplastics pollution in our drinking water. A total of 40 bottled MW and DW samples from 4 local products in Sarawak and Malaysia was investigated. A filtration and observation processes using the membrane filters (0.45 μm pore size) and digital microscope (Nikon Eclipse LV150N) were developed to identify and quantify the presence of microplastics based on their types, shapes, and sizes as criteria. A library database was also developed to ensure the consistency of this identification process. A total of 2022 microplastics with an average of 50.6 particles per bottle (500-mL packing) was detected in the samples. Bead, fibre, fragment and film were detected in all the samples, but fibre (48%) and fragment (36%) made up the majority (84%) of microplastics in the samples. However, microplastics in the MW samples were found 13% higher than the DW samples. This was also true across the products investigated in this study except between X (MW) and Z (DW). On the other hand, the results also indicated that the majority (66.7%) of microplastics smaller than 20 μm were consistently detected in all the samples. Nevertheless, other detection methods such as Raman, Fourier Transform Infrared (FTIR) Spectroscopy, etc. should be considered for a more thorough investigation. Lastly, it is important to revisit the sampling and testing procedures for similar studies like this to prevent or minimize any cross-contamination to the samples.

In this paper, results of feasibility study on microplastics (MPs) assessment in leachates from the Latvian solid municipal landfill Getliņi are discussed. The application of leachates for the treatment of cigarette butts (CGB) was evaluated. Methods of fluorescent microscopy, Fourier transform infrared (FTIR) spectroscopy and FTIR-microscopy were used for the identification and characterization of MPs in the leachates and analysis of CGB. Presence of the secondary MPs (e.g., degraded polyolefin mixtures) was determined in the tested landfill leachates, while cellulose acetate (CA) was not determined in these products. The leachates were tested as potential media for the thermophilic (55°C) fermentation of CGB without air supply. Degradation of CGB was determined after one-week fermentation that was confirmed comparing the changes in FTIR spectra of CA prior and after the treatment. This study provoked a path for further experimental studies of controlled degradation of cigarette butts under natural conditions in landfill environments.

Pollution by microplastics is of increasing concern due to their ubiquitous presence in most biological and environmental media, their potential toxicity and their ability to carry other contaminants. Knowledge on microplastics in freshwaters is still in its infancy. Here we reviewed 150 investigations to identify the common methods and tools for sampling microplastics, waters and sediments in freshwater ecosystems. Manta trawls are the main sampling tool for microplastic separation from surface water, whereas shovel, trowel, spade, scoop and spatula are the most frequently used devices in microplastic studies of sediments. Van Veen grab is common for deep sediment sampling. There is a need to develop optimal methods for reducing identification time and effort and to detect smaller-sized plastic particles.

Microplastic (MP) is currently a subject of discussion in all parts of the world because it has increasingly over the years become the dominant source of pollution in marine ecosystem. Huge number of these Mps emanate from waste management, decommissioning of ships and oil rigs, plastic products in aquaculture and fishery, sewage treatment, consumer products, agricultural production, transportation, offshore oil and gas production and city dust and wears. Microplastic are characteristically non- biodegradable or durable, exhibits buoyancy, travel long distances, complex with toxic chemicals and bioaccumulate being invisible to the human eye. Classification of MPs into primary and secondary based on source and established standard protocols visa-vis the sampling and identification in matrices were critically reviewed. Physicochemical processes for identification of MPs such as pyrolysis-Gas chromatography/Mass spectrometry, FTIR, Raman spectroscopy, SEM-GS and TGA/MS were reviewed. Deleterious chemicals such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dioxins, phthalates, polycyclic aromatic hydrocarbons (PAHs) and persistent organic chemicals (POCs) associated with MPs and mechanisms of chelation were appraised. Several menace and health hazards such as hepatic inflammation, genetic mutation, increase in reactive oxygen species (ROS) /oxidative stress, tissue necrosis and proliferation of cells linked with MPs were also discussed. Furthermore, green approaches to arresting the menace such as replacing polymer products with biopolymer an eco-friendly alternative, recycling of plastic products, use of paper bags and glass materials and abrogation of consumer products laced with microbeads were advocated.

The continuous increases in temperature and microplastic concentration have raised grave concerns worldwide. The influence of water temperature and microplastic concentration on microplastic ingestion and retention rates in Holothuria cinerascens (Brandt, 1835) was investigated. H. cinerascens were sampled by handpicking during low tide from Park Rynie beach on the south coast of KwaZulu-Natal, South Africa. They were then cleaned and transported to the control temperature room. Animals were placed in pairs in aerating tanks and acclimated for 48 h. For the exposure experiment, 50, 100, and 150 polyethylene fragments per litre of sizes (0.5–1 mm and 1–2 mm) were added to each tank at varied temperatures (19, 24, 28, and 32 °C) and were left for 48 h and 72 h. Thereafter, animals were transferred to tanks void of microplastics and left to depurate for 48 h for the retention experiment. Microplastic collected from the gut and faecal samples were used to calculate the ingestion and retention rates. Water temperature significantly influenced ingestion and retention rates, while microplastic concentration influenced the ingestion rate only. The highest microplastic particle number/g.h was recorded in high microplastic concentration for both ingestion and retention experiments. Also, the highest microplastic particle number/g.h was obtained at 28 °C in the ingestion experiment. More microplastic particle number/g.h was retained at 19 °C in the ingestion experiment. Ingestion rate increased with increased microplastic concentration, and temperature up to 28 °C and then decreased at 32 °C. More microplastics were retained at high temperature (28 °C) and low temperature (19 °C) at 48 h and 72 h exposure, respectively. Increase in water temperature and microplastic concentration will increase the susceptibility of H. cinerascens to ingest more microplastics from their natural habitat.

As a persistent pollutant, microplastics (MPs) have been reported to induce sperm quantity decrease in mice. However, the related mechanism remains obscure. Therefore, this study is intended to explore the effects of polystyrene microplastics (PS-MPs) on male reproduction and its related mechanism of blood-testis barrier (BTB) impairment. Thirty-two adult male Wistar rats were divided randomly into four groups fed with PS-MPs for 90 days at doses of 0 mg/day (control group), 0.015 mg/day, 0.15 mg/day, and 1.5 mg/day, respectively. The present results have shown that PS-MP exposure led to the damage of seminiferous tubule, resulted in apoptosis of spermatogenic cells, and decreased the motility and concentration of sperm, while the abnormality of sperm was elevated. Meanwhile, PS-MPs could induce oxidative stress and activate the p38 MAPK pathway and thus deplete the nuclear factor erythroid-2 related factor 2 (Nrf2). Noteworthily, PS-MPs led to the BTB-related protein expression decrease. All these results demonstrated that PS-MP exposure may lead to the destruction of BTB integrity and the apoptosis of spermatogenic cells through the activation of the MAPK-Nrf2 pathway. The current study provided novelty evidence for elucidating the effects of PS-MPs on male reproductive toxicity and its potential mechanism.