Microplastics In Ecosystems Research Articles

In vivo visualization of environmentally relevant microplastics and evaluation of gut barrier damages in Artemia franciscana

Although irregularly-shaped label-free microplastics (MPs) are predominantly distributed in the environment, non-destructive analysis of environmentally relevant MPs in organisms is still challenging. The purpose of the study is to suggest in vivo visual evidence of the uptake and effect of environmentally relevant MPs in organism. Transparent irregularly-shaped high-density polyethylene was selected as an environmentally relevant model MP and exposed to brine shrimp (Artemia franciscana). As a result, we suggest the application of SEM/EDX and coherent anti-Stokes Raman scattering (CARS) microspectroscopy as complementary tools to secure in vivo visual evidence of irregularly-shaped unlabeled MPs in living organisms without chemical digestion for biodistribution observations. Biological transmission electron microscopy also provides how ingested MPs physically affects the digestive tract in the brine shrimp which is rarely reported. In terms of environmental implications, this study would advance ecotoxicological research on microplastic pollution by providing a cutting-edge tool for investigating the bioavailability and ecotoxicity of environmentally relevant MPs in ecosystems.

Homogenization of bacterial plastisphere community in soil: a continental-scale microcosm study.

Microplastics alter niches of soil microbiota by providing trillions of artificial microhabitats, termed the "plastisphere." Because of the ever-increasing accumulation of microplastics in ecosystems, it is urgent to understand the ecology of microbes associated with the plastisphere. Here, we present a continental-scale study of the bacterial plastisphere on polyethylene microplastics compared with adjacent soil communities across 99 sites collected from across China through microcosm experiments. In comparison with the soil bacterial communities, we found that plastispheres had a greater proportion of Actinomycetota and Bacillota, but lower proportions of Pseudomonadota, Acidobacteriota, Gemmatimonadota, and Bacteroidota. The spatial dispersion and the dissimilarity among plastisphere communities were less variable than those among the soil bacterial communities, suggesting highly homogenized bacterial communities on microplastics. The relative importance of homogeneous selection in plastispheres was greater than that in soil samples, possibly because of the more uniform properties of polyethylene microplastics compared with the surrounding soil. Importantly, we found that the degree to which plastisphere and soil bacterial communities differed was negatively correlated with the soil pH and carbon content and positively related to the mean annual temperature of sampling sites. Our work provides a more comprehensive continental-scale perspective on the microbial communities that form in the plastisphere and highlights the potential impacts of microplastics on the maintenance of microbial biodiversity and ecosystem functioning.

Microplastics in ecosystems and health

Microplastics are very small plastic particles, less than 5mm in diameter. These materials may originate from the degradation of larger plastic products, such as bottles and bags, or may be intentionally manufactured for use in cosmetics. Microplastics are a significant environmental problem because they can be ingested by marine animals and other living things, causing them significant damage. Furthermore, these materials can act as toxic contaminants. The objective of this study is to know and understand the negative effects of microplastics on ecosystems, and on human health, and to know the technologies that are being used to reduce this type of contamination through recycling and the development of alternatives to plastic, as well as knowing the policies that are being developed to address this problem. This study seeks to create greater public awareness of the problem, improve understanding of the effects on ecosystems, and identify the sources and routes of entry of microplastics into the environment. In summary, research on microplastics is essential to address the problem of plastic pollution and to find effective solutions to protect our environment and health.

Review of green technologies for the removal of microplastics from diverse environmental sources

AbstractMicroplastics are the basic particles (1 µm–1 mm), derived from degradation of polymers with maximum molecular weight via various sources. They occur in a variety of shapes and sizes, in the form of domains, particles, and fibers. Release of Microplastics in the ecosystem, due to deterioration of macroplastics are now being considered as major toxic pollutants. Accumulation of microplastics in the diverse ecosystems is known to cause severe health and ecological effects. Since it is mandatory to take steps towards the removal of microplastics through effective and safe technology, with this objective, the present study is undertaken to reveal various green technology principles for the management of microplastics contamination associated with diverse environmental sources. This strategy involves physical methods, chemical methods, biological methods that under the conventional measures and nanotechnology principles as modern remediation. Physical methods involve filtration, membrane‐technology and adsorption. Chemical remediation involves hydrolysis, alcoholysis, acidolysis, glycolysis, aminolysis, photocatalytic degradation and electrochemical oxidation resulting in decomposition of microplastics into simpler, non‐toxic end products. Biological methods involve biosorption, microbial degradation, microbial ingestion and phytoremediation, where plants or plant biomass can be used for removal of microplastics via phytoaccumulation, phytostabilization, phytovolatilization and phytofiltration. Nano technology remediation utilizes nanoscale materials as adsorbents. Due to its unique nanosize, high surface area and energy, nanomaterials are considered effective adsorbents of microplastics. Microplastics can also be detected and identified using machine learning approaches. The present study implies that, the green technology principles can be effectively utilized for the removal of microplastics associated with diverse ecosystem.

Leveraging deep learning for automatic recognition of microplastics (MPs) via focal plane array (FPA) micro-FT-IR imaging

The fast and accurate identification of MPs in environmental samples is essential for the understanding of the fate and transport of MPs in ecosystems. The recognition of MPs in environmental samples by spectral classification using conventional library search routines can be challenging due to the presence of additives, surface modification, and adsorbed contaminants. Further, the thickness of MPs also impacts the shape of spectra when FTIR spectra are collected in transmission mode. To overcome these challenges, PlasticNet, a deep learning convolutional neural network architecture, was developed for enhanced MP recognition. Once trained with 8000 + spectra of virgin plastic, PlasticNet successfully classified 11 types of common plastic with accuracy higher than 95%. The errors in identification as indicated by a confusion matrix were found to be caused by edge effects, molecular similarity of plastics, and the contamination of standards. When PlasticNet was trained with spectra of virgin plastic it showed good performance (92%+) in recognizing spectra that had increased complexity due to the presence of additives and weathering. The re-training of PlasticNet with more complex spectra further enhanced the model's capability to recognize complex spectra. PlasticNet was also able to successfully identify MPs despite variations in spectra caused by variations in MP thickness. When compared with the performance of the library search in identifying MPs in the same complex dataset collected from an environmental sample, PlasticNet achieved comparable performance in identifying PP MPs, but a 17.3% improvement. PlasticNet has the potential to become a standard approach for rapid and accurate automatic recognition of MPs in environmental samples analyzed by FPA FT-IR imaging.

The Microplastics Iceberg: Filling Gaps in Our Understanding.

Plastic is an indispensable material in modern society; however, high production rates combined with inadequate waste management and disposal have resulted in enormous stress on ecosystems. In addition, plastics can become smaller particles known as microplastics (MPs) due to physical, chemical, and biological drivers. MP pollution has become a significant environmental problem affecting terrestrial and aquatic ecosystems worldwide. Although the topic is not entirely new, it is of great importance to the field of polymers, drawing attention to specific gaps in the existing literature, identifying future areas of research, and improving the understanding of MP pollution and its environmental impacts. Despite progress in this field, problems remain. The lack of standardized methods for MP sampling, separation, extraction, and detection makes it difficult to collect information and establish links between studies. In addition, the distribution and pathways of MPs in ecosystems remain unknown because of their heterogeneous nature and the complex matrices in which they occur. Second, toxicological tests showed that MPs can be ingested by a wide range of organisms, such as Danio rerio and Eisenia fetida, resulting in gut obstruction, physical damage, histological changes, and oxidative stress. The uptake of MP and their toxicological effects depend on their shape, size, concentration, and polymer composition. Furthermore, MPs can enter the food chain, raising concerns regarding potential contaminations for human and environmental health. This review paper sheds light on the pressing issue of MP pollution and highlights the need for interdisciplinary collaboration between scientists, policymakers, and industry leaders.

Interactions between polypropylene microplastics (PP-MPs) and humic acid influenced by aging of MPs

As an emerging pollutant, microplastics (MPs) may interact with dissolved organic matter (DOM) which is prevalent in the aqueous environment. Meanwhile, the aging of MPs in the actual environment increases the uncertainty of their environmental fate. Here, the interaction mechanisms between pristine and aged polypropylene microplastics (PP-MPs) and humic acid (HA) at pH 7.0 were explored. Microstructural changes of HA were examined by fluorescence and Fourier transformation infrared (FT-IR) spectroscopy. Atomic force microscopy coupled with infrared (AFM-IR) and micro-Raman techniques were used to characterize and analyze the interacted PP-MPs. The addition of HA increased the surface roughness of both pristine and aged PP-MPs. Results of AFM-IR and Raman spectra showed that the interaction of PP-MPs with HA accelerated their surface oxidation and enhanced the characteristic signals. XPS spectra showed that the oxygen content ratio of pristine and aged PP-MPs increased by 0.95% and 1.48% after the addition of HA, respectively. PP-MPs after aging interacted more strongly with HA and there was a higher affinity between them. Two-dimensional correlation spectroscopy (2D-COS) combined with FT-IR spectra further elucidated the interaction mechanism at the molecular level. This work will help to evaluate the environmental impact of MPs in ecosystems and understand their interactions with DOM.

Microplastics in ecosystems: their implications and mitigation pathways

Microplastic (MP) pollution is an emerging threat to terrestrial and aquatic ecosystems.

Progress in quantitative analysis of microplastics in the environment: A review

The amount of plastics released into the environment has been increasing dramatically. As the physical and chemical degradation of plastics results in the production of millimeter- and micrometer-sized plastic particles, their presence has been recognized as an environmental threat. Considerable efforts have been made to identify and quantify microplastics in ecosystems. Millimeter-sized plastic particles can be monitored visually, but confirmation of the type of plastic requires spectroscopic tools such as Fourier-transform infrared spectroscopy, Raman spectroscopy, optical microscopy, and scanning electron microscopy combined with energy-dispersive X-ray spectroscopy. These technologies have long been considered robust methods for the identification of diverse plastic materials, but are not suitable for the quantification of concentrations in the environment using conventional analytical tools. The accuracy of plastic identification also decreases as the size of the particles approaches the scale of a few micrometers. Here, up-to-date technical developments in the identification and quantification of microplastics using pyrolysis–gas chromatography/mass spectrometry (Pyro-GC/MS) are reviewed along with their advantages, disadvantages, and accompanying technical challenges.

Microplastics in Ecosystems: From Current Trends to Bio-Based Removal Strategies.

Plastics are widely used due to their excellent properties, inexpensiveness and versatility leading to an exponential consumption growth during the last decades. However, most plastic does not biodegrade in any meaningful sense; it can exist for hundreds of years. Only a small percentage of plastic waste is recycled, the rest being dumped in landfills, incinerated or simply not collected. Waste-water treatment plants can only minimize the problem by trapping plastic particles of larger size and some smaller ones remain within oxidation ponds or sewage sludge, but a large amount of microplastics still contaminate water streams and marine systems. Thus, it is clear that in order to tackle this potential ecological disaster, new strategies are necessary. This review aims at briefly introducing the microplastics threat and critically discusses emerging technologies, which are capable to efficiently clean aqueous media. Special focus is given to novel greener approaches based on lignocellulose flocculants and other biomaterials. In the final part of the present review, it was given a proof of concept, using a bioflocculant to remove micronized plastic from aqueous medium. The obtained results demonstrate the huge potential of these biopolymers to clean waters from the microplastics threat, using flocculants with appropriate structure.

Induced structural changes of humic acid by exposure of polystyrene microplastics: A spectroscopic insight.

The occurrence of microplastics (MPs) as emerging contaminants in the environment may cause changes in water or sediment characteristics, and further affect their biogeochemical cycles. Thus, insights into the interactions between dissolved organic matter (DOM) and MPs are essential for the assessment of environmental impacts of MPs in ecosystems. Integrating spectroscopic methods with chemometric analyses, this work explored the chemical and microstructural changes of DOM-MP complex to reveal the mechanism of DOM-MP interaction at a molecular level. MPs were found to interact with the aromatic structure of DOM via π-π conjugation, then be entrapped in the DOM polymers by the carboxyl groups and C=O bonds, constituting a highly conjugated co-polymer with increased electron density. This induced the fluorescence intensity increase in DOM. The interaction affinity of DOM-MP was highly dependent on the MP size and solution pH. This work offers a new insight into the impact of MP discharge on environment and may provide an analytical framework for evaluating MP hetero-aggregation and the roles of MPs in the transportation of other contaminants. Furthermore, the integrated methods used in this work exhibit potential applications in exploring the fragmentation processes of MPs and formation of secondary MPs under natural conditions.