Microplastics

2024

Jump to: 2023, 2022, 2021

14 pages, 2031 KiB

Open AccessArticle

Unraveling Plastic Pollution in Protected Terrestrial Raptors Using Regurgitated Pellets

by Chloe Wayman, Francisca Fernández-Piñas, Irene López-Márquez, Rocío Fernández-Valeriano, Juan José Iglesias-Lebrija, Fernando González-González, Roberto Rosal and Miguel González-Pleiter

Microplastics 2024, 3(4), 671-684; https://doi.org/10.3390/microplastics3040041 - 8 Nov 2024

Viewed by 658

Abstract

The threat of plastic pollution has escalated to unprecedented levels, with particular concern surrounding microplastics (MPs) and artificial fibers or particles (AFs) due to their wide distribution across ecosystems and their bioavailability to wildlife. Although research on the impact of plastic on wild [...] Read more.

The threat of plastic pollution has escalated to unprecedented levels, with particular concern surrounding microplastics (MPs) and artificial fibers or particles (AFs) due to their wide distribution across ecosystems and their bioavailability to wildlife. Although research on the impact of plastic on wild birds is rapidly growing, knowledge of terrestrial species remains limited, especially regarding raptors, which have been significantly understudied. Here, we investigated the prevalence of MPs and AFs in regurgitated pellets from six protected terrestrial raptor species, namely the Cinereous Vulture (Aegypius monachus), the Bonelli’s Eagle (Aquila fasciata), the Little Owl (Athene noctua), the Lesser Kestrel (Falco naumanni), the Red Kite (Milvus milvus), and the Barn Owl (Tyto alba), collected between 2022 and 2023. Our analysis revealed that 68% of the pellets contained MPs (47 out of 69), and 81% contained AFs (56 out of 69). Additionally, two macroplastics were found inside the pellets: a cable tie in a Red Kite and a bird identification ring in a Cinereous Vulture. The concentrations (mean ± standard error of the mean) were 2.39 ± 0.39 MPs/pellet and 5.16 ± 0.72 AFs/pellet. The concentration of MPs and AFs varied significantly among some of the studied species; however, no significant differences were observed among urban, rural, and protected areas. This could indicate that contamination levels are mainly related to the type of species. Fibers emerged as the predominant contaminant shape, with six different polymers identified, among which PET, PE, and acrylics were the most prevalent. These findings highlight that plastic pollution has reached protected terrestrial raptors and that the impact of plastic on their life cycles needs to be assessed. Full article

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15 pages, 2689 KiB

Open AccessArticle

Mitigating Microfiber Pollution in Laundry Wastewater: Insights from a Filtration System Case Study in Galle, Sri Lanka

by Mahagama Gedara Yohan Lasantha Mahagamage, Sachith Gihan Gamage, Rathnayake Mudiyanselage Shehan Kaushalya Rathnayake, Premakumara Jagath Dickella Gamaralalage, Matthew Hengesbugh, Thejani Abeynayaka, Chathura Welivitiya, Lahiru Udumalagala, Chathura Rajitha and Supun Suranjith

Microplastics 2024, 3(4), 599-613; https://doi.org/10.3390/microplastics3040037 - 20 Oct 2024

Viewed by 846

Abstract

Synthetic fibers are widely used in daily life due to their durability, elasticity, low cost, and ease of use. The textile industry is the primary source of synthetic microfibers, as these materials are mostly used in production processes. Globally, plastic pollution has been [...] Read more.

Synthetic fibers are widely used in daily life due to their durability, elasticity, low cost, and ease of use. The textile industry is the primary source of synthetic microfibers, as these materials are mostly used in production processes. Globally, plastic pollution has been identified as a major environmental threat in this era, since plastics are not degradable but break down into smaller particles such as mesoplastics, microplastics, and microfibers. Synthetic microfiber pollution is a significant issue in aquatic ecosystems, including oceans and rivers, with laundry wastewater being a major source. This problem is particularly pressing in cities like Galle, Sri Lanka, where numerous tourist hotels are located. Despite the urgency, there has been a lack of scientific and systematic analysis to fully understand the extent of the issue. This study addresses this gap by analyzing the generation of microfibers from laundry activities at a selected hotel and evaluating the efficiency of a laundry wastewater filtration system. This study focused on a fully automatic front-loading washing machine (23 kg capacity) with a load of 12 kg of polyester–cotton blend serviettes (black and red). Samples (1 L each) were taken from both treated and untreated wastewater during four wash cycles, with a total of 100 L of water used for the process. The samples were filtered through a 100 μm sieve and catalytic wet oxidation along with density separation were employed to extract the microfibers, which were then collected on a membrane filter paper (0.45 μm). Microfibers were observed and analyzed for shapes, colors and sizes under a stereo microscope. Results revealed that untreated laundry wastewater contained 10,028.7 ± 1420.8 microfibers per liter (n = 4), while treated wastewater samples recorded 191.5 ± 109.4 microfibers per liter (n = 4). Most of the microfibers observed were black and white/transparent colors. Further analysis revealed that 1 kg of polyester–cotton blend fabric can generate 336,833 microfibers per wash, which was reduced to 6367 microfibers after treatment. The filtration unit recorded an impressive efficiency of 98.09%, indicating a remarkably high capacity for removing microfibers from wastewater. These findings highlight the potential of such filtration techniques to significantly reduce microfiber emissions from laundry wastewater, presenting a promising approach to mitigating environmental pollution from microfibers. Full article

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10 pages, 3239 KiB

Open AccessArticle

Characterization of Microplastics in Bees and Their Products in Urban and Rural Areas of the Sabana De Bogotá, Colombia

by Luis David Gómez-Méndez, Jorge E. Robles-Camargo, Ricardo Vera-Bravo, Angela M. Moncaleano-Niño, Carlos A. Devia Castillo, Rodulfo Ospina-Torres, Yisela Escobar-Cortés, Mariana Camacho-Erazo and Angela R. Amarillo-Suárez

Microplastics 2024, 3(4), 589-598; https://doi.org/10.3390/microplastics3040036 - 10 Oct 2024

Viewed by 790

Abstract

Microplastics, plastic fragments smaller than 5 mm present in the environment due to the decomposition of larger plastics, can cause damage to various ecosystems and species of pollinating insects, such as Apis mellifera bees. These bees play a crucial role in the ecology [...] Read more.

Microplastics, plastic fragments smaller than 5 mm present in the environment due to the decomposition of larger plastics, can cause damage to various ecosystems and species of pollinating insects, such as Apis mellifera bees. These bees play a crucial role in the ecology and production of honey and pollen, also serving as bioindicators of environmental quality as they are sensitive to contaminants such as microplastics. In this study, we evaluated the presence of microplastics in these insects and their products—pollen, and honey—collected in August 2021 and August 2023 in rural areas (Tabio and Guasca) of Cundinamarca, Colombia, and urban areas (Universidad Nacional de Colombia and Pontificia Universidad Javeriana) of Bogotá, Colombia. Each year, 24 bees, 10 g of honey, and 5 g of pollen were collected per sampling point. Microplastics in bees and their products were identified and quantified by stereomicroscopy, with or without hydrogen peroxide digestion pretreatment. Microplastics were found in bees, pollen, and honey in both periods, with an increase in their quantity observed over time due to increasing environmental pollution. Blue fibers were the most common microplastics, with a greater amount recorded in 2023 compared to 2021. Full article

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30 pages, 2108 KiB

Open AccessReview

Microplastics in Farmed Animals—A Review

by Maximilian Lackner and Manuela Branka

Microplastics 2024, 3(4), 559-588; https://doi.org/10.3390/microplastics3040035 - 30 Sep 2024

Viewed by 2047

Abstract

Environmental pollution from plastics has become one of the biggest concerns globally. Microplastics (MPs) are plastic materials less than 5 mm in size. They remain in the environment for hundreds to thousands of years without degrading, only breaking down further to nanoplastics (NPs). [...] Read more.

Environmental pollution from plastics has become one of the biggest concerns globally. Microplastics (MPs) are plastic materials less than 5 mm in size. They remain in the environment for hundreds to thousands of years without degrading, only breaking down further to nanoplastics (NPs). Micro- and nanoplastics can be the origin of many diseases and can carry various pathogenic substances on their surface and spread them throughout the biosphere, starting with contained additives and ending with adsorbed toxins from the environment and potentially pathogenic microorganisms. Exposure routes for humans and animals are through air, water and food/feed. Due to the placement of livestock—including ruminants, fish and poultry—and humans at the top of the food web, any pollution in water, air or soil can eventually be transferred to livestock and from livestock to humans. The presence of microplastics in the intestines of aquaculture species, ruminants and poultry, for instance, was found to cause a change in the intestinal microbial population and, as a result, the occurrence of diseases. These particles have also been observed in other organs such as liver, kidneys, lung, spleen, heart, ovaries, and testicles of animals, which causes biochemical changes, structural destruction, and malfunction. While the complete extent of the negative health impacts of microplastics remains still largely unknown, their ubiquitous presence and the transmission of chemicals from microplastics to organisms is a notable issue, underscoring the importance of gaining a more comprehensive understanding of the potential threats posed by microplastics to animal and ultimately human health, coupled with a need for drastic reduction of the plastic freight into the environment. This review article summarizes recent findings on the effect of micro- and nanoplastics on farmed animals and, ultimately, on humans. Action is needed to reduce the number of microplastics to which farmed animals, and thereby humans, are exposed. Full article

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14 pages, 3378 KiB

Open AccessArticle

Numerical and Experimental Approach to Evaluate Microplastic Transport in Saturated Porous Media

by Hande Okutan, Çağdaş Sağır, Bedri Kurtuluş, Hasan Burak Özmen, Emrah Pekkan, Moumtaz Razack and Philippe Le Coustumer

Microplastics 2024, 3(3), 463-476; https://doi.org/10.3390/microplastics3030029 - 12 Aug 2024

Cited by 1 | Viewed by 796

Abstract

Under varying flow rate conditions, the transport and retention of polydisperse microplastics (MPls), with an average particle size of 16 ± 6 µm, were investigated in saturated porous media. First-order reversible and irreversible kinetic sorption models were used to describe the sorption kinetics. [...] Read more.

Under varying flow rate conditions, the transport and retention of polydisperse microplastics (MPls), with an average particle size of 16 ± 6 µm, were investigated in saturated porous media. First-order reversible and irreversible kinetic sorption models were used to describe the sorption kinetics. Sensitivity analyses provided insight into the effects of each sorption parameter. Both numerical modeling and experimental measurements were utilized to evaluate the retention rates of sand filters. The influence of flow rate on sorption was reflected in variations in the distribution coefficient (K_d), the mass transfer coefficient (β), and the irreversible sorption rate (K₁). Lower flow rates were associated with higher K_d and β values, indicating increased sorption and reduced mass transfer rates. An increase in K_d resulted in a more gradual sorption process, with a decrease in peak concentration, whereas changes in β had a comparatively smaller impact on sorption rate and peak concentration. Lower K₁ values were linked to higher peak concentrations and decreased retention efficiency. Numerical modeling revealed retention rates of 28 ± 1% at a flow rate of 31 mL min⁻¹ and 17 ± 1% at 65 mL min⁻¹. The introduction of MPls into saturated sand environments modifies the transport dynamics within the medium. Consequently, these alterations affect the hydrological characteristics of porous media, impacting groundwater quality and agricultural output. The mean absolute error (MAE) of 6% between the modeled and observed retention rates indicated a high level of accuracy. This study underscores the importance of examining retention efficiency and the accuracy of numerical models in understanding MPl transport in porous media. Full article

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17 pages, 2364 KiB

Open AccessArticle

Earthworm (Eisenia andrei)-Mediated Degradation of Commercial Compostable Bags and Potential Toxic Effects

by Luís André Mendes, Ricardo Beiras and Jorge Domínguez

Microplastics 2024, 3(2), 322-338; https://doi.org/10.3390/microplastics3020020 - 8 Jun 2024

Cited by 2 | Viewed by 1147

Abstract

The availability of compostable plastic bags has increased greatly in the past few years, as it is perceived that this type of bags will be degraded after disposal. However, there are some knowledge gaps regarding the potential effects on the soil ecosystems. We [...] Read more.

The availability of compostable plastic bags has increased greatly in the past few years, as it is perceived that this type of bags will be degraded after disposal. However, there are some knowledge gaps regarding the potential effects on the soil ecosystems. We assessed the rate of degradation of samples of four different types of commercial compostable bags in vermicomposting systems with the earthworm species Eisenia andrei. We also evaluated the biological response of E. andrei (survival and reproduction) to microplastics (MPs) from fragments of the plastic bags (<2000 µm) and assessed seedling emergence in common garden cress (Lepidium sativum L.) exposed to micronized plastic (<250 µm) and the respective leachate, following OECD and ISO guidelines, respectively. The rate of degradation differed significantly depending on the type of plastic rather than the substrate in the vermicomposting system. This finding suggests that the degradation process is more dependent on the microbial community colonizing the different plastic types than on earthworm activity. Regarding the biological response of the soil system, L. sativum seedling emergence was not significantly affected; however, earthworm reproduction was affected, suggesting that although compostable, some of the formulations may potentially be toxic to soil fauna. Full article

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12 pages, 2299 KiB

Open AccessArticle

Uptake and Cellular Effects of Polymethylmethacrylate on Human Cell Lines

by Arthur Braun and Harald Seitz

Microplastics 2024, 3(2), 205-216; https://doi.org/10.3390/microplastics3020012 - 5 Apr 2024

Cited by 2 | Viewed by 1727

Abstract

The usage of plastic and its decomposition products leads to their ubiquitous distribution, resulting in their uptake by all living beings, including humans. Polymethylmethacrylate (PMMA) is known as a biocompatible polymer and is used widely in medicine and dentistry, although recent findings have [...] Read more.

The usage of plastic and its decomposition products leads to their ubiquitous distribution, resulting in their uptake by all living beings, including humans. Polymethylmethacrylate (PMMA) is known as a biocompatible polymer and is used widely in medicine and dentistry, although recent findings have shown its induction of oxidative stress within cells. Worryingly, hardly any data exist investigating the uptake of PMMA particles by cells, the potential effects of these particles on cells and cell signaling pathways and their contributing factors. We assessed the uptake of PMMA beads via confocal microscopy after their incubation with HEK293, A549 and MRC5 cells. Through cell staining, we localized multiple PMMA beads within the cytosol of cells. No alterations regarding cell growth, cell morphology or cell division were found, implying no short-term toxicity towards human cells. Using a cAMP response element binding protein (CREB)-mediated reporter assay, we assessed whether internalized PMMA nanobeads alter cell signaling pathways after stimulation of the cells. CREB was chosen as a well-described transcription factor involved in various cellular processes. Our data led to the assumption that PMMA nano- and microbeads are internalized via endocytosis and end up in lysosomes within the cell cytosol. We concluded that differences regarding the surface composition of the PMMA nanobeads affect their potential to alter cell signaling. These findings emphasize the key role the surface composition plays regarding microplastics and their risks for human health, whereas the usage of medical-grade PMMA remains safe. Full article

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23 pages, 23119 KiB

Open AccessArticle

An Image-Processing Tool for Size and Shape Analysis of Manufactured Irregular Polyethylene Microparticles

by Melanie Fritz, Lukas F. Deutsch, Karunia Putra Wijaya, Thomas Götz and Christian B. Fischer

Microplastics 2024, 3(1), 124-146; https://doi.org/10.3390/microplastics3010008 - 9 Feb 2024

Cited by 2 | Viewed by 2060

Abstract

Microplastics (MPs) pose a significant risk to humans and animals due to their ability to absorb, adsorb, and desorb organic pollutants. MPs catchment from either sediments or water bodies is crucial for risk assessment, but fast and effective particle quantification of irregularly shaped [...] Read more.

Microplastics (MPs) pose a significant risk to humans and animals due to their ability to absorb, adsorb, and desorb organic pollutants. MPs catchment from either sediments or water bodies is crucial for risk assessment, but fast and effective particle quantification of irregularly shaped particles is only marginally addressed. Many studies used microscopy methods to count MP particles, which are tedious for large sample sizes. Alternatively, this work presents an algorithm developed in the free software GNU Octave to analyze microscope images of MP particles with variable sizes and shapes. The algorithm can detect and distinguish different particles, compensate for uneven illumination and low image contrast, find high-contrast areas, unify edge regions, and fill the remaining pixels of stacked particles. The fully automatic algorithm calculates shape parameters such as convexity, solidity, reciprocal aspect ratio, rectangularity, and the Feret major axis ratio and generates the particle size distribution. The study tested low-density polyethylene particles with sizes of 50–100 µm and 200–300 µm. A scanning electron microscope image series analyzed with Octave was compared to a manual evaluation using ImageJ. Although the fully automatic algorithm did not identify all particles, the comprehensive tests demonstrate a qualitatively accurate particle size and shape monitoring applicable to any MPs, which processes larger data sets in a short time and is compatible with MATLAB-based codes. Full article

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26 pages, 5749 KiB

Open AccessReview

Advancements and Regulatory Situation in Microplastics Removal from Wastewater and Drinking Water: A Comprehensive Review

by Vyoma Jani, Shenghua Wu and Kaushik Venkiteshwaran

Microplastics 2024, 3(1), 98-123; https://doi.org/10.3390/microplastics3010007 - 8 Feb 2024

Cited by 5 | Viewed by 3521

Abstract

In recent years, the ubiquitous occurrence of plastic debris has become a significant environmental concern, posing considerable harm to our ecosystems. Microplastics (MPs) (1 μm–5 mm) and nanoplastics (NPs) (<1 μm) are noticeable in diverse forms, spreading throughout the environment. Notably, wastewater treatment [...] Read more.

In recent years, the ubiquitous occurrence of plastic debris has become a significant environmental concern, posing considerable harm to our ecosystems. Microplastics (MPs) (1 μm–5 mm) and nanoplastics (NPs) (<1 μm) are noticeable in diverse forms, spreading throughout the environment. Notably, wastewater treatment plants (WWTPs) emerge as major contributors to the generation of MP and NP. Within these treatment plants, water influx from domestic and commercial sources carries a considerable load of MPs derived from items like fiber clothing, personal care products, and toothpaste. Lacking dedicated removal mechanisms, these MPs persist through the wastewater treatment process, ultimately entering natural water bodies and the soil environment. The novelty of this review lies in its detailed examination of contemporary methodologies for sampling, detecting, and eliminating MPs specifically from WWTPs. By critically assessing the efficacy of current removal techniques at various treatment stages, the review offers targeted insights into practical aspects of MP management in these facilities. As the study of micro/nano plastics is still in its early stages, this article aims to contribute by offering a comprehensive review of the methods utilized for plastic debris removal in both WWTPs and drinking water treatment plants (DWTPs). Furthermore, the article provides a comprehensive overview of the existing rules, regulations, and policies concerning MPs in the United States. This inclusion not only broadens the scope of the review but also establishes it as a valuable reference for understanding the regulatory framework related to MPs. This review uniquely combines a focused evaluation of WWTPs/DWTPs, an exploration of removal methods, and an examination of regulatory framework, making a different contribution to the review article. Through this review, we aim to enhance understanding and awareness of the multi-layered challenges posed by MPs, offering insights that can inform future research directions and policy initiatives. Full article

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16 pages, 1754 KiB

Open AccessReview

Micro- and Nanoplastics in the Atmosphere: Methodology for Microplastics Size-Fractionation Sampling

by Yuliya Logvina, Isabel M. Matas, Helena Ribeiro, Luís Pinto da Silva, Pedro Rodrigues, João Leitão and Joaquim Esteves da Silva

Microplastics 2024, 3(1), 82-97; https://doi.org/10.3390/microplastics3010006 - 8 Feb 2024

Cited by 3 | Viewed by 1886

Abstract

Micro- and nanoplastics (MNPs) are an important atmospheric aerosol constituent. However, there still needs to be a standard procedure for their sampling and size fractionation, which is an obstacle to the aggregation and critical analysis of results obtained by different research groups. This [...] Read more.

Micro- and nanoplastics (MNPs) are an important atmospheric aerosol constituent. However, there still needs to be a standard procedure for their sampling and size fractionation, which is an obstacle to the aggregation and critical analysis of results obtained by different research groups. This review focuses on the sampling and fractionation methodologies used for MNPs. Moreover, a streamlined, simplified methodology for sampling and fractionation is proposed. Full article

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15 pages, 4369 KiB

Open AccessArticle

A Feasible and Efficient Monitoring Method of Synthetic Fibers Released during Textile Washing

by Oskar Świątek and Agnieszka Dąbrowska

Microplastics 2024, 3(1), 67-81; https://doi.org/10.3390/microplastics3010005 - 30 Jan 2024

Viewed by 1442

Abstract

Microfibers (MFs) are one of the most common and hazardous forms of microplastic found in the aquatic environment. The methods of collecting and analyzing MFs released during washing have to be developed and standardized to understand and model the process of microfibers’ emission [...] Read more.

Microfibers (MFs) are one of the most common and hazardous forms of microplastic found in the aquatic environment. The methods of collecting and analyzing MFs released during washing have to be developed and standardized to understand and model the process of microfibers’ emission better. This study tests a new, innovative method to check if laundry fiber sampling can be approached comprehensively. Pieces of synthetic materials (aged and new polyester, polyester-cotton blend) were placed in chromium-nickel filters envelope-like folded. Then, textile weathering during washing was monitored by the quality and quantity of fibers found directly on the filter surface. Laundry parameters like temperature, detergent presence, and filter size were changed, and results were monitored by Fourier-transform infrared spectroscopy (FTIR), a well-known standard in microplastic identification. In addition, ATR spectra were collected to characterize the materials in detail and evaluate their aging level. Spectroscopy can be used to detect and examine both mechanical and chemical degradation, and the collected microfibers can be assigned to the material they come from. Finally, a quantitative comparison of fibers released during different washing conditions can be used for the process optimization to minimize its environmental impact. Full article

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2023

Jump to: 2024, 2022, 2021

21 pages, 4980 KiB

Open AccessArticle

Experimental Validation of the Microplastic Index—Two Approaches to Understanding Microplastic Formation

by Kalouda Grigoriadi, Merel G. A. Nooijens, Ali Emre Taşlı, Max M. C. Vanhouttem, Sieger Henke, Luke A. Parker, Jan Harm Urbanus and Arjen Boersma

Microplastics 2023, 2(4), 350-370; https://doi.org/10.3390/microplastics2040027 - 3 Nov 2023

Viewed by 1786

Abstract

The Microplastic Index (MPI) was presented in a previous paper as a method to assess the formation of microplastics during the application of impact and wear stresses, based on selected mechanical and physical properties of polymers. In this paper, the experimental validation of [...] Read more.

The Microplastic Index (MPI) was presented in a previous paper as a method to assess the formation of microplastics during the application of impact and wear stresses, based on selected mechanical and physical properties of polymers. In this paper, the experimental validation of the MPI model is presented. A series of ten polymers was characterized to obtain the relevant parameters for the calculation of the MPI, i.e., the minimum particle size and volume of microplastics formed. The milling (addressing impact stress) and sanding experiments (addressing wear stress) resulted in particle sizes between 3 and 200 μm and 0.3 and 25 μm, respectively. These values were very well predicted by the MPI model, showing smaller particles for brittle polymers and larger ones for ductile polymers. In addition, the experimental-specific wear rates of impact and wear correlated well with the predicted ones, being 0.01–30 mm³/Nm for impact and 0.0002–0.012 mm³/Nm for wear. These results indicate that the MPI can be very well used to predict the tendency of a material to form microplastics. In the search for understanding and mitigating microplastic formation, the MPI can be used by both producers and end users to choose plastic grades that form fewer microplastics. Full article

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16 pages, 11845 KiB

Open AccessArticle

Fast Forward: Optimized Sample Preparation and Fluorescent Staining for Microplastic Detection

by Michael Toni Sturm, Erika Myers, Anika Korzin, Sabrina Polierer, Dennis Schober and Katrin Schuhen

Microplastics 2023, 2(4), 334-349; https://doi.org/10.3390/microplastics2040026 - 22 Oct 2023

Cited by 3 | Viewed by 2475

Abstract

The fast, affordable, and standardized detection of microplastics (MP) remains one of the biggest challenges in MP research. Comparable data are essential for appropriate risk assessments and the implementation of laws and limit values. The fluorescent staining of MP in environmental samples is [...] Read more.

The fast, affordable, and standardized detection of microplastics (MP) remains one of the biggest challenges in MP research. Comparable data are essential for appropriate risk assessments and the implementation of laws and limit values. The fluorescent staining of MP in environmental samples is a possible solution to this problem. This study investigates the optimization of a sample preparation process (hydrogen peroxide digestion) and the staining process (temperature, concentration, time, surfactants as staining aids) for using a specifically developed fluorescent dye for MP detection. The optimization is performed by comparing the sample preparation process and staining of MP from different polymers and natural particles. Further, the suitability of the optimized process for the detection of fluoropolymers and tire abrasion was tested. The results show that the optimized method (increased temperature and optimized stain concentration) can detect microplastics reliably with a total sample preparation and measurement time of 2.5–3 h per sample, reaching recovery rates of 93.3% (polypropylene) to 101.7% (polyester). Moreover, two of the three tested fluoropolymers could be detected reliably. Tire abrasion could not be detected with the here presented method, as the black color leads to strong quenching. A long-term study measuring the MP pollution in the effluent of a municipal wastewater treatment plant compared the optimized and original processes and confirmed the stability of the improved method for routine measurements and contamination control. Full article

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12 pages, 5009 KiB

Open AccessArticle

Comparing Methods for Microplastic Quantification Using the Danube as a Model

by Tim Kiefer, Martin Knoll and Andreas Fath

Microplastics 2023, 2(4), 322-333; https://doi.org/10.3390/microplastics2040025 - 17 Oct 2023

Cited by 2 | Viewed by 1318

Abstract

This study investigates the impact different mesh-sized filtration methods have on the amount of detected microplastics in the surface water of the Danube River delta. Further, the distribution of microplastics in different size categories (20 µm, 65 µm, 105 µm) and in the [...] Read more.

This study investigates the impact different mesh-sized filtration methods have on the amount of detected microplastics in the surface water of the Danube River delta. Further, the distribution of microplastics in different size categories (20 µm, 65 µm, 105 µm) and in the water column (0 m, 3 m, 6 m) was analyzed. Our findings show that the Danube River carries 46 p∙L⁻¹ (microplastic particles per liter) with a size larger than 105 µm, 95 p∙L⁻¹ larger than 65 µm and 2677 p∙L⁻¹ that are larger than 20 µm. This suggests a negative logarithmic correlation between mesh size and particle amount. The most abundant polymer throughout all samples was polyethylene terephthalate, followed by polytetrafluorethylene. Overall, the data shows that different sampling methods cannot be compared directly. Further research is needed to find correlations in particle sizes for better comparison between different sampling methods. Full article

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13 pages, 3473 KiB

Open AccessArticle

Characterization of Microplastics and Mesoplastics and Presence of Biofilms, Collected in the Gualí Wetland Cundinamarca, Colombia

by Maria Alejandra Porras-Rojas, Cristina Charry-Vargas, Jorge Leonardo Muñoz-Yustres, Paula Martínez-Silva and Luis David Gómez-Méndez

Microplastics 2023, 2(3), 255-267; https://doi.org/10.3390/microplastics2030021 - 1 Aug 2023

Cited by 3 | Viewed by 2628

Abstract

Wetlands are being contaminated by housing developments, effluents, industrial areas, and poor sanitation, resulting in the presence of plastic polymers and the development of biofilms on these materials, which represent an elevated risk to freshwater fauna and flora. The objective of this study [...] Read more.

Wetlands are being contaminated by housing developments, effluents, industrial areas, and poor sanitation, resulting in the presence of plastic polymers and the development of biofilms on these materials, which represent an elevated risk to freshwater fauna and flora. The objective of this study was to characterize mesoplastics and microplastics, collected in the Gualí Wetland, Colombia, as well as to verify the presence of biofilms on such polymers. Nine water samples (36 L per sample) were evaluated at three points of the wetland; the size of the particles was determined by image analysis, the type of polymer through FTIR, and the presence of biofilms by microscopy. A total of 79 items/0.135 m³ were collected, 2 macroplastic items, 53 mesoplastic items, and 24 microplastic items. The presence of fragments (70%) and pellets (41%), with transparent (40%) and white (30%) being the predominant ones, was outstanding. Among the polymers, high-density polyethylene (HDPE) dominated, followed by expanded polystyrene. The results of SEM demonstrated the presence of diatoms on the surface of the plastic polymers. Furthermore, the results showed a greater amount of HDPE mesoplastics and microplastics in the shape of fragments and pellets. In addition, the presence of biofilms on these plastic particles can increase the adsorption of contaminants, negatively affecting this ecosystem. The outcome of this study can be used to identify bacteria that reside in biofilms associated with microplastics and mesoplastics. Full article

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10 pages, 3135 KiB

Open AccessArticle

Impact of Degradation of Polyethylene Particles on Their Cytotoxicity

by Yudai Ikuno, Hirofumi Tsujino, Yuya Haga, Haruyasu Asahara, Kazuma Higashisaka and Yasuo Tsutsumi

Microplastics 2023, 2(2), 192-201; https://doi.org/10.3390/microplastics2020015 - 22 May 2023

Cited by 8 | Viewed by 2750

Abstract

Microplastics are ubiquitous in the environment, including in the ocean, soil, and air. Therefore, there are concerns regarding human exposure. Since it is known that the surface of microplastics in various environments is chemically deteriorated by external factors such as ultraviolet rays and [...] Read more.

Microplastics are ubiquitous in the environment, including in the ocean, soil, and air. Therefore, there are concerns regarding human exposure. Since it is known that the surface of microplastics in various environments is chemically deteriorated by external factors such as ultraviolet rays and waves, it is essential to evaluate the biological effects of degraded microplastics. In this study, we experimented by accelerating the degradation of polyethylene (PE) using vacuum ultraviolet light and prepared PE samples with different degrees of degradation. Then, we evaluated the effects of undegraded and variously degraded PE on cells using cytotoxicity tests. Based on the cytotoxicity test results, we saw a tendency for increased cytotoxicity with increasing degradation. Therefore, this study substantially links the deterioration of microplastics with their biological effects. Full article

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14 pages, 44278 KiB

Open AccessArticle

Microplastic Contamination in Cultured Mussels and Pearl Oysters in Greece

by Stefania M. Manolaki, Dimitra Chatzivasileiou, Maria Lampa, Panagiotis D. Dimitriou, Aggelos Philippidis, Ioannis Karakassis and Nafsika Papageorgiou

Microplastics 2023, 2(2), 168-181; https://doi.org/10.3390/microplastics2020013 - 3 Apr 2023

Cited by 4 | Viewed by 3110

Abstract

Τhis study aims to measure the abundance of microplastic (MP) particles in the soft tissue of mussel (Mytilus galloprovincialis) and pearl oyster (Pinctada imbricata radiata) specimens. Samples were collected at four sites in Greece (Sagiada, Malesina, Elounda, Rhodes) from [...] Read more.

Τhis study aims to measure the abundance of microplastic (MP) particles in the soft tissue of mussel (Mytilus galloprovincialis) and pearl oyster (Pinctada imbricata radiata) specimens. Samples were collected at four sites in Greece (Sagiada, Malesina, Elounda, Rhodes) from wild and farmed populations. The identification of MPs was accomplished by Raman spectroscopy. Comparisons were made between the two different species where the two species co-existed (Malesina), between the four study sites (five sampling stations) in relation to P. imbricata radiata individuals, and also in every station for the different MP types found. For the specimens from Malesina, M. galloprovincialis had more MPs in their soft tissue compared to P. imbricata radiata. Microfibers were found in abundance in M. galloprovincialis, while microfragments were found in P. imbricata radiata specimens. The main MP type found in P. imbricata radiata specimens was microfragments in all five sampling stations, and ranged between 1.54 ± 0.63 (Rhodes-baskets) and 3.56 ± 0.35 (Sagiada) MP particles/g. While the samples of mussels and pearl oysters were similar in age, the differences found in the concentrations of MPs appears to be due to their different farming methods and location characteristics concerning the five sampling stations of pearl oysters. This study indicates that the culturing system does not affect MP concentration in bivalves, and further investigation is needed to find the most appropriate method to limit and reduce MPs that end up in the farmed organisms. Full article

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10 pages, 2459 KiB

Open AccessArticle

Promotion of DNA Adsorption onto Microplastics by Transition Metal Ions

by Lyuyuan Wu, Kshiti Patel, Mohamad Zandieh and Juewen Liu

Microplastics 2023, 2(1), 158-167; https://doi.org/10.3390/microplastics2010012 - 6 Mar 2023

Cited by 5 | Viewed by 3913

Abstract

Microplastics can adsorb and spread a variety of pollutants in the ecosystem posing a threat to human health. One of the common pollution sources of environmental waters is metal ions, which not only adsorb on microplastics but can also promote the adsorption of [...] Read more.

Microplastics can adsorb and spread a variety of pollutants in the ecosystem posing a threat to human health. One of the common pollution sources of environmental waters is metal ions, which not only adsorb on microplastics but can also promote the adsorption of other invasive species such as environmental DNA. Recently, we showed that environmentally abundant metal ions (Na⁺, Mg²⁺ and Ca²⁺) can promote the adsorption of single-stranded DNA (ssDNA) onto microplastics. Herein, we investigated the effect of transition metal ions including Zn²⁺ and Mn²⁺ and compared them with Mg²⁺ for promoting DNA adsorption. To better mimic environmental DNA, we also used a salmon sperm double-stranded DNA (dsDNA) (~2000 bp). For both ssDNA and dsDNA, the transition metals induced a higher adsorption capacity compared to Mg²⁺, and that correlated with the higher binding affinity of transition metals to DNA. Although metal-mediated interactions were vital for ssDNA adsorption, the dsDNA adsorbed on the microplastics even in the absence of metal ions, likely due to the abundance of binding sites of the 100-times longer dsDNA. Finally, desorption studies revealed that hydrophobic interactions were responsible for dsDNA adsorption in the absence of metal ions. Full article

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11 pages, 1423 KiB

Open AccessArticle

Characterization of Large Microplastic Debris in Beach Sediments in the Po Delta Area

by Luca Cozzarini, Joana Buoninsegni, Corinne Corbau and Vanni Lughi

Microplastics 2023, 2(1), 147-157; https://doi.org/10.3390/microplastics2010011 - 3 Mar 2023

Cited by 3 | Viewed by 2409

Abstract

The use of single-use or disposable plastic objects has massively increased during the last few decades, and plastic has become the main type of litter found in marine environments. The Adriatic Sea is seriously prone to marine litter pollution, and it collects about [...] Read more.

The use of single-use or disposable plastic objects has massively increased during the last few decades, and plastic has become the main type of litter found in marine environments. The Adriatic Sea is seriously prone to marine litter pollution, and it collects about one-third of all the freshwater flowing into the Mediterranean, mainly via the river Po. This study investigated the type and composition of large microplastic debris collected in different sites in the Po Delta area. Visual classification was performed by relevant criteria, while chemical composition was assessed by infrared spectroscopy. The main plastic fraction is composed of polyolefin (76%), followed by polystyrene (19%). This proportion roughly matches global plastic production, rescaled after excluding plastics with negative buoyancy: all the identified compounds have a specific gravity lower than that of the seawater. Fragments (irregularly shaped debris) represent the most abundant category fraction (85%), followed by pellets, which represent roughly 10% of the total. Overall, the results provided an insight into large microplastic pollution in beach sediments in the Po delta area. Full article

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15 pages, 2259 KiB

Open AccessArticle

A Public Database for Microplastics in the Environment

by Natalja Čerkasova, Kristina Enders, Robin Lenz, Sonja Oberbeckmann, Josef Brandt, Dieter Fischer, Franziska Fischer, Matthias Labrenz and Gerald Schernewski

Microplastics 2023, 2(1), 132-146; https://doi.org/10.3390/microplastics2010010 - 15 Feb 2023

Cited by 9 | Viewed by 5065

Abstract

During recent years plastics became one of the focuses of EU policy. A harmonisation and comparability of microplastics monitoring results across Europe is needed. The complexity of microplastic data makes it necessary to develop a specific, tailor-made database rather than adapting and modifying [...] Read more.

During recent years plastics became one of the focuses of EU policy. A harmonisation and comparability of microplastics monitoring results across Europe is needed. The complexity of microplastic data makes it necessary to develop a specific, tailor-made database rather than adapting and modifying one of the existing databases. To meet this demand, we present a publicly accessible, flexible, and extendable structured relational database for particle-based microplastic data. The developed relational database is adaptive and meets the specific demands of microplastics, e.g., a large variety of sampling, processing and analytical methods, many types of plastics, and a very wide size spectrum ranging from micrometres to millimetres. In this paper we discuss the development of the database, data entry specifics, sample analysis methods, microplastics data manipulation and quality assurance, and database integration and accessibility. Full article

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15 pages, 4907 KiB

Open AccessArticle

Influx of Near-Infrared Technology in Microplastic Community: A Bibliometric Analysis

by Monika Rani, Serena Ducoli, Stefania Federici and Laura Eleonora Depero

Microplastics 2023, 2(1), 107-121; https://doi.org/10.3390/microplastics2010008 - 13 Feb 2023

Cited by 7 | Viewed by 2634

Abstract

The abundance of microplastics in the environment poses a constant threat to all parts of the ecosystem, and the scientific community is called upon to help solve the problem. Numerous studies have been published for microplastic analysis, especially in the last decade, with [...] Read more.

The abundance of microplastics in the environment poses a constant threat to all parts of the ecosystem, and the scientific community is called upon to help solve the problem. Numerous studies have been published for microplastic analysis, especially in the last decade, with vibrational spectroscopy being the preferred method. According to recent literature, portable spectrometers operating in the near-infrared (NIR) range are being used for the analysis of different types of polymers, and this technique has recently found its way into the analysis of microplastics as a good alternative to expensive and complicated benchtop instruments, such as Fourier-transform infrared (FTIR) spectrometers. The aim of this study is to investigate and evaluate research trends, leading publications, authors, countries, and limitations of the use of NIR spectroscopy in microplastics research, with a comparison to the established FTIR technique. Full article

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14 pages, 3589 KiB

Open AccessArticle

May a Former Municipal Landfill Contaminate Groundwater in Microplastics? First Investigations from the “Prairie de Mauves Site” (Nantes, France)

by Lauriane Ledieu, Ngoc-Nam Phuong, Bernard Flahaut, Pauline Radigois, Julya Papin, Cécile Le Guern, Batrice Béchet and Johnny Gasperi

Microplastics 2023, 2(1), 93-106; https://doi.org/10.3390/microplastics2010007 - 6 Feb 2023

Cited by 9 | Viewed by 3505

Abstract

Municipal landfills receive a high amount of plastic waste and due to the occurring physical and biochemical degradation processes, could be significant sources of microplastics (MP). Evaluating the threat to groundwater through the transfer of MP via landfill leachates require more research. The [...] Read more.

Municipal landfills receive a high amount of plastic waste and due to the occurring physical and biochemical degradation processes, could be significant sources of microplastics (MP). Evaluating the threat to groundwater through the transfer of MP via landfill leachates require more research. The former “Prairie de Mauves” landfill, operated from 1963 to 1987 by the municipality of Nantes (France), and located above the alluvial groundwater of the Loire River, represents a good candidate for such investigations. Leachates and groundwater were sampled along a transect line from upstream to downstream of the landfill, in March and June 2022. MP (>25 µm) were quantified and characterized using µFTIR imaging in transmission mode. MP were observed in every sample with concentrations ranging from 0.71 to 106.7 MP/L. Concentrations in the leachates and the alluvial groundwater illustrate a migration of MP. Twelve polymers were identified and polyethylene (PE) and polypropylene (PP) were predominant. After a conventional rainfall event (14.3 mm), higher concentrations, diversity, and size ranges of MP were observed. Water infiltration through the heterogeneous geological substratum therefore enhanced the migration of larger MP towards the alluvial groundwater of the Loire River. Full article

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16 pages, 2399 KiB

Open AccessReview

The Complex Dynamics of Microplastic Migration through Different Aquatic Environments: Subsidies for a Better Understanding of Its Environmental Dispersion

by Marcelo Pompermayer de Almeida, Christine Gaylarde, Fabiana Cunha Pompermayer, Leonardo da Silva Lima, Jessica de Freitas Delgado, Danniela Scott, Charles Vieira Neves, Khauê Silva Vieira, José Antônio Baptista Neto and Estefan Monteiro Fonseca

Microplastics 2023, 2(1), 62-77; https://doi.org/10.3390/microplastics2010005 - 19 Jan 2023

Cited by 12 | Viewed by 4413

Abstract

Microplastic pollution in aquatic ecosystems has drawn attention not only because microplastics are likely to accumulate anywhere but also because they cause negative impacts both to aquatic biota and, indirectly, to public health, as a result of their presence. The understanding of the [...] Read more.

Microplastic pollution in aquatic ecosystems has drawn attention not only because microplastics are likely to accumulate anywhere but also because they cause negative impacts both to aquatic biota and, indirectly, to public health, as a result of their presence. The understanding of the distribution and accumulation patterns of this “new contaminant” is fundamental for the calibration of environmental risk studies. However, research on its migration pattern and consequent distribution is still limited. The present study has focused on the peculiar physical characteristics of plastic microparticles and the response to environmental factors such as hydrodynamics and physical chemistry of water on the diffusion dynamics of these pollutant agents. Therefore, we examined information about the vertical abundance distribution, the composition, and the sizes of microplastics, along with the varied aquatic environments existing on Earth. This study provides valuable evidence for the accumulation trend of microplastics across the environment and the peculiar particle characteristics that dictate their distribution patterns. The present study concluded that detailed studies should be carried out in order to add information about the behavior of plastic microparticles in aquatic environments and thus subsidize the calibration of existing information, thus increasing its accuracy in understanding the diffusion patterns of these polluting agents. Full article

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2022

Jump to: 2024, 2023, 2021

12 pages, 12939 KiB

Open AccessArticle

Effect of Polystyrene Microplastics in Different Diet Combinations on Survival, Growth and Reproduction Rates of the Water Flea (Daphnia magna)

by Melek Isinibilir, Kamil Mert Eryalçın and Ahmet Erkan Kideys

Microplastics 2023, 2(1), 27-38; https://doi.org/10.3390/microplastics2010002 - 23 Dec 2022

Cited by 6 | Viewed by 3130

Abstract

Microplastic pollution is a problem not only in the marine environment but also in freshwater ecosystems. Water flea (Daphnia magna) is one of the most common omnivorous cladocerans in freshwater ecosystems. In this study, the potential effects of microplastics (fluorescent polystyrene [...] Read more.

Microplastic pollution is a problem not only in the marine environment but also in freshwater ecosystems. Water flea (Daphnia magna) is one of the most common omnivorous cladocerans in freshwater ecosystems. In this study, the potential effects of microplastics (fluorescent polystyrene beads with dimensions of 6 microns) on the survival, growth and reproduction of Daphnia magna were examined during 21 days of laboratory experiments. Microplastics (MPs) were observed to be ingested alone or along with either the microalgae Chlorella vulgaris (Cv) or baker’s yeast (By). D. magna fed exclusively with microplastics showed a drastic decline in survival similar to that in the starving group. The least growth in total length or width was observed in Daphnia specimens fed only MPs and the starved groups. Daphia fed with a mixture of MPs/Cv or MPs/By produced a significantly (p < 0.05) lower number of ephippia. Our results show that high concentrations of microplastics adversely affect Daphnia magna populations. Full article

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26 pages, 1904 KiB

Open AccessReview

Microplastics: A Review of Policies and Responses

by Davi R. Munhoz, Paula Harkes, Nicolas Beriot, Joana Larreta and Oihane C. Basurko

Microplastics 2023, 2(1), 1-26; https://doi.org/10.3390/microplastics2010001 - 23 Dec 2022

Cited by 20 | Viewed by 12960

Abstract

Although (micro)plastic contamination is a worldwide concern, most scientific literature only restates that issue rather than presenting strategies to cope with it. This critical review assembles the current knowledge on policies and responses to tackle plastic pollution, including peer-reviewed scientific literature, gray literature [...] Read more.

Although (micro)plastic contamination is a worldwide concern, most scientific literature only restates that issue rather than presenting strategies to cope with it. This critical review assembles the current knowledge on policies and responses to tackle plastic pollution, including peer-reviewed scientific literature, gray literature and relevant reports to provide: (1) a timeline of policies directly or indirectly addressing microplastics; (2) the most up-to-date upstream responses to prevent microplastics pollution, such as circular economy, behavioral change, development of bio-based polymers and market-based instruments as well as source-specific strategies, focusing on the clothing industry, tire and road wear particles, antifouling paints and recreational activities; (3) a set of downstream responses tackling microplastics, such as waste to energy, degradation, water treatment plants and litter clean-up strategies; and examples of (4) multifaceted responses focused on both mitigating and preventing microplastics pollution, e.g., approaches implemented in fisheries and aquaculture facilities. Preventive strategies and multifaceted responses are postulated as pivotal to handling the exacerbated release of microplastics in the environment, while downstream responses stand out as auxiliary strategies to the chief upstream responses. The information gathered here bridges the knowledge gaps on (micro)plastic pollution by providing a synthesized baseline material for further studies addressing this environmental issue. Full article

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14 pages, 1008 KiB

Open AccessReview

Microfibers: Environmental Problems and Textile Solutions

by Judith S. Weis and Francesca De Falco

Microplastics 2022, 1(4), 626-639; https://doi.org/10.3390/microplastics1040043 - 1 Nov 2022

Cited by 16 | Viewed by 10279

Abstract

Microplastics have become a topic of considerable concern and intensive study over the past decade. They have been found everywhere in the oceans, including the deepest trenches and remotest parts of the Arctic. They are ingested by many animals and some are incorporated [...] Read more.

Microplastics have become a topic of considerable concern and intensive study over the past decade. They have been found everywhere in the oceans, including the deepest trenches and remotest parts of the Arctic. They are ingested by many animals and some are incorporated into tissues. There is considerable effort in studying what effects they have on marine life. It has become clear that when water samples are collected in ways that prevent most long thin particles from escaping through pores of a net, the most abundant type of microplastics found in water and sediments are microfibers (fibers with dimensions less than 5 mm). The major source of these pollutants is synthetic textiles, such as polyester or polyamides, which shed microfibers during their entire life cycle. Microfibers are released during textile manufacturing, everyday activities (e.g., washing, drying, wearing) and final disposal. The complexity of microfiber release mechanisms and of the factors involved make the identification and application of ways to reduce the inputs of microfibers very challenging. A comprehensive approach is strongly needed, taking into account solutions at a number of levels, such as re-engineering textiles to minimize shedding, applying washing machine filters, developing advanced wastewater treatment plants and improving the management of textile wastes. To harmonize and make mandatory the solutions identified, a variety of potential government policies and regulations is also needed. Full article

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16 pages, 2481 KiB

Open AccessReview

Opening Space for Plastics—Why Spatial, Soil and Land Use Data Are Important to Understand Global Soil (Micro)Plastic Pollution

by Collin J. Weber and Moritz Bigalke

Microplastics 2022, 1(4), 610-625; https://doi.org/10.3390/microplastics1040042 - 8 Oct 2022

Cited by 10 | Viewed by 4225

Abstract

After five years of research on microplastic pollution of soils it becomes obvious that soil systems act as a reservoir for microplastics on global scales. Nevertheless, the exact role of soils within global microplastic cycles, plastic fluxes within soils and environmental consequences are [...] Read more.

After five years of research on microplastic pollution of soils it becomes obvious that soil systems act as a reservoir for microplastics on global scales. Nevertheless, the exact role of soils within global microplastic cycles, plastic fluxes within soils and environmental consequences are so far only partly understood. Against the background of a global environmental plastic pollution, the spatial reference, spatial levels, sampling approaches and documentation practices of soil context data becomes important. Within this review, we therefore evaluate the availability of spatial MP soil data on a global scale through the application of a questionnaire applied to 35 case studies on microplastics in soils published since 2016. We found that the global database on microplastics in soils is mainly limited to agricultural used topsoils in Central Europe and China. Data on major global areas and soil regions are missing, leading to a limited understanding of soils plastic pollution. Furthermore, we found that open data handling, geospatial data and documentation of basic soil information are underrepresented, which hinders further understanding of global plastic fluxes in soils. Out of this context, we give recommendations for spatial reference and soil context data collection, access and combination with soil microplastic data, to work towards a global and free soil microplastic data hub. Full article

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23 pages, 9287 KiB

Open AccessArticle

Effects of Silica Fume and Micro Silica on the Properties of Mortars Containing Waste PVC Plastic Fibers

by Rawa Ahmed Mahmood and Niyazi Ugur Kockal

Microplastics 2022, 1(4), 587-609; https://doi.org/10.3390/microplastics1040041 - 7 Oct 2022

Cited by 6 | Viewed by 4242

Abstract

Investigations on the usability of waste plastics as a new generation of construction materials have become one of the main concerns of researchers and engineers in recent decades. Waste plastics can be used either as aggregate replacement or as fiber reinforcement to enhance [...] Read more.

Investigations on the usability of waste plastics as a new generation of construction materials have become one of the main concerns of researchers and engineers in recent decades. Waste plastics can be used either as aggregate replacement or as fiber reinforcement to enhance the properties of cementitious mixtures. This study focuses on the properties of waste PVC fiber-reinforced mortars containing silica fume and micro silica. Plastic fibers were added to the mortar mixes by volume fractions of 0%, 1%, 2%, and 3%. Cement was replaced by micro silica and silica fume by 5%, 10%, and 15% by weight of cement, respectively. In total, 28 different groups of mortars were produced. The results showed an enhanced ductility and deformation behavior of mortars upon the addition of waste PVC plastic fibers. It can be seen that fibers restricted crack propagation and maintained integrity, hence improving the ductility of the mortars. On the other hand, the addition of fibers led to a reduction in the physical and mechanical properties of the mortar samples. The compressive strength of the mortar samples decreased gradually by increasing the fiber content. Cement replacement by silica fume improved mechanical and microstructural properties of the mortars. The results also demonstrated that silica fume significantly decreased the porosity and water absorption capacity of mortar samples. Full article

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15 pages, 5561 KiB

Open AccessArticle

Detection and Analysis of Microfibers and Microplastics in Wastewater from a Textile Company

by Sinem Hazal Akyildiz, Rossana Bellopede, Hande Sezgin, Ipek Yalcin-Enis, Bahattin Yalcin and Silvia Fiore

Microplastics 2022, 1(4), 572-586; https://doi.org/10.3390/microplastics1040040 - 3 Oct 2022

Cited by 16 | Viewed by 3921

Abstract

Textile wastewater is polluted by inorganic/organic substances, polymers, dyes, and microfibers (MFs), which are microplastics (MPs) and natural fibers. This work is aimed at the preliminary investigation of MFs and MPs in textile industrial wastewater, and at evaluating the removal efficiency of an [...] Read more.

Textile wastewater is polluted by inorganic/organic substances, polymers, dyes, and microfibers (MFs), which are microplastics (MPs) and natural fibers. This work is aimed at the preliminary investigation of MFs and MPs in textile industrial wastewater, and at evaluating the removal efficiency of an on-site wastewater treatment plant (WWTP). Ten samples of inflows and outflows of the WWTP of a textile company (applying a physic-chemical process) have been analyzed. Firstly, the samples underwent a pretreatment with 15% hydrogen peroxide at 25 °C for 5 days to remove organic compounds. Secondly, the MFs were recovered from the aqueous phase by pre-screening centrifugation, density separation, and filtration as alternative options. Filtration obtained the best performances, compared to the other recovery processes. Thirdly, the MFs were counted through optical microscopy and the MPs were identified through micro-FTIR. The MFs amount in the inflow samples was in the range of 893–4452 MFs/L. The outflow samples (310–2404 MFs/L) exhibited a 38–65% reduction compared to the inflows, demonstrating that up to 62% of residual MFs can enter the sewer network or the receiving water body. Cotton and wool, and numerous MPs (acrylic, polyester, polypropylene, polyamide, and viscose/rayon) were identified in the inflow and outflow samples (with the only exception of “dense” viscose (rayon), not detected in the outflows, and probably retained by the WWTP with the sludge). This study, even if just preliminary, offers interesting hints for future research on MFs/MPs detection in textile wastewater, and on the performance of a full-scale WWT process for their removal. Full article

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18 pages, 5388 KiB

Open AccessReview

Marine Litter Impact on Sandy Beach Fauna: A Review to Obtain an Indication of Where Research Should Contribute More

by Leonardo Lopes Costa, Lucia Fanini, Mohamed Ben-Haddad, Maurizio Pinna and Ilana Rosental Zalmon

Microplastics 2022, 1(3), 554-571; https://doi.org/10.3390/microplastics1030039 - 9 Sep 2022

Cited by 25 | Viewed by 5738

Abstract

In order to identify how research contributes to the knowledge of marine litter as a pressure on beaches, we reviewed interactions of beach fauna with this pollutant. Entanglement of pinnipeds in fishing gear, negative correlations between macroinvertebrates abundance and sediment pollution, and the [...] Read more.

In order to identify how research contributes to the knowledge of marine litter as a pressure on beaches, we reviewed interactions of beach fauna with this pollutant. Entanglement of pinnipeds in fishing gear, negative correlations between macroinvertebrates abundance and sediment pollution, and the presence of plastic surrounding burrows were primary evidence of beach fauna interacting with stranded litter. Ingestion represents the main body of research; microplastic uptake by invertebrates has been studied by laboratory experiments and field collections to report the presence of polymers in tissues. In the natural context, the higher the urbanization surrounding beaches and sediment pollution, the higher the concentration of microplastics in organs of bivalves. This approach currently constitutes the main research direction, but ecotoxicological assays are emerging prospects to assess the effects of exposure to microplastics. Beached macroplastics entangle and entrap invertebrates and vertebrates, and studies have reported increasing negative interactions with seals and sea turtles. Changes in nesting and feeding behavior of resident and transient organisms have been shown as typical early warning indicators of marine litter impacts. The focus on fauna–litter interactions holds terrific potential for research and citizen science projects, which finally becomes a powerful driver towards environmental awareness on sandy beaches. Full article

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11 pages, 2045 KiB

Open AccessArticle

Assessment of Polyester Fabrics, Effluents and Filtrates after Standard and Innovative Washing Processes

by Tanja Pušić, Branka Vojnović, Mirjana Čurlin, Ivica Bekavac, Tea Kaurin, Katia Grgić, Kristina Šimić and Zorana Kovačević

Microplastics 2022, 1(3), 494-504; https://doi.org/10.3390/microplastics1030035 - 2 Sep 2022

Cited by 1 | Viewed by 2299

Abstract

Textile materials from polyester fibres are sensitive to washing, especially at higher temperatures, due to their thermoplastic properties, hydrophobic nature and sensitivity to the alkaline medium. The issue of microplastic fibres’ (MFs’) release from polyester textiles is a topic that attracts the attention [...] Read more.

Textile materials from polyester fibres are sensitive to washing, especially at higher temperatures, due to their thermoplastic properties, hydrophobic nature and sensitivity to the alkaline medium. The issue of microplastic fibres’ (MFs’) release from polyester textiles is a topic that attracts the attention of researchers from different scientific fields, since microplastics are now among the serious environmental risks. In this study, two washing protocols, a standard and an innovative procedure, were presented, aiming to preserve the properties of polyester fabrics and reduce the pollution of washing effluents. The standard procedure followed HRN EN ISO 6330, while the innovative procedure was a modification of the standard that involved gradually cooling the bath before rinsing. The effects of these washing protocols were studied based on the physicochemical properties of the fabrics compared to the unwashed material, the composition of the effluents, and the filtrates after 10 cycles. The characterisation parameters of the fabrics, effluents and filtrates according to the standard and the innovative washing protocols showed differences in the observed parameters during the 10 washing cycles. The obtained results show the usefulness of the proposed concept of cooling the bath before rinsing in order to preserve the properties of polyester fabrics and reduce the load of washing effluents. Hierarchical cluster analysis (HCA) also confirmed differences in pH, conductivity and turbidity for effluents and filtrates from standard and innovative washing protocols. Full article

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21 pages, 6388 KiB

Open AccessArticle

Investigating the Physicochemical Property Changes of Plastic Packaging Exposed to UV Irradiation and Different Aqueous Environments

by Wihann Conradie, Christie Dorfling, Annie Chimphango, Andy M. Booth, Lisbet Sørensen and Guven Akdogan

Microplastics 2022, 1(3), 456-476; https://doi.org/10.3390/microplastics1030033 - 17 Aug 2022

Cited by 11 | Viewed by 3799

Abstract

A wide range of weathering processes contributes to the degradation of plastic litter items which leads to the formation of microplastics that may be detrimental to marine ecosystems and the organisms inhabiting them. In this study, the impact of UV exposure on the [...] Read more.

A wide range of weathering processes contributes to the degradation of plastic litter items which leads to the formation of microplastics that may be detrimental to marine ecosystems and the organisms inhabiting them. In this study, the impact of UV exposure on the degradation of clear polypropylene (CPP), black polypropylene (BPP), and polyethylene terephthalate (PET) packaging materials was investigated over a period of 6 weeks under dry air conditions representing the terrestrial environment. The exposure was conducted using differently sized and shaped samples at irradiation intensities of 65 W/m² and 130 W/m². Results indicated that UV irradiation led to changes in the properties of PET, BPP, and CPP that were proportional to the intensity delivered, leading to a higher level of mass loss, carbonyl indices, crystallinities, and microhardness in all polymer types at 130 W/m² relative to 65 W/m². However, material shape and size did not have a significant influence on any property for any of the test materials. Increased mass loss over time was accompanied by considerable increases in carbonyl index (CI) for both PPs. Clear PP (CPP) underwent the most severe degradation, resulting in the highest mass loss, increase in crystallinity, and CI. BPP was less degraded and modified by the UV irradiation than the CPP, indicating that the colorant, carbon black, provided some degree of protection to the bulk polymer material. PET was the least degraded of the three materials, suggesting this polymer type is more resistant to UV degradation. The differences in the degradation behaviours of the three test materials under dry environmental conditions indicate that the UV exposure history of plastic litter might play an important role in its potential for further degradation once it reaches the marine environment. Furthermore, analysis of samples exposed to UV in aqueous media reveals a more irregular set of trends for most material properties measured. Overall, the degree of degradation resulting from UV irradiation in dry environments was more pronounced than in aqueous environments, although the most significant property changes were observed for materials without previous UV exposure histories. Samples with previous UV histories showed higher resistance to further crystallinity changes, which appeared to be due to crosslinking in the pretreatment exposures inhibiting chain alignment into crystalline structures. The effect of solution medium was insignificant, although the presence of water allowed hydrolytic degradation to proceed simultaneously with UV degradation for PET. The reduction of CI in pretreated materials in the aqueous exposures, combined with the mass loss, suggest that the degraded surface layer erodes or products dissolve into surrounding solution medium, leaving a fresh surface of plastic exposed. Full article

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12 pages, 3738 KiB

Open AccessArticle

Low-Density Polyethylene Migration from Food Packaging on Cured Meat Products Detected by Micro-Raman Spectroscopy

by Klytaimnistra Katsara, George Kenanakis, Eleftherios Alissandrakis and Vassilis M. Papadakis

Microplastics 2022, 1(3), 428-439; https://doi.org/10.3390/microplastics1030031 - 12 Aug 2022

Cited by 9 | Viewed by 5055

Abstract

Food packaging has been demonstrated as a crucial issue for the migration of microplastics (MPs) into foodstuffs, concerning human health risk factors. Polymeric materials called plastics are continuously utilized in food packaging. Polyethylene (PE) is commonly used as a food packaging material, because [...] Read more.

Food packaging has been demonstrated as a crucial issue for the migration of microplastics (MPs) into foodstuffs, concerning human health risk factors. Polymeric materials called plastics are continuously utilized in food packaging. Polyethylene (PE) is commonly used as a food packaging material, because it offers easy handling during transportation and optimal storage conditions for food preservation. In this work, three types of cured meat products of different fat compositions and meat processing methods—bacon, mortadella, and salami—were studied using spectroscopic methods (Raman and FT–IR/ATR) to determine the migration of low-density polyethylene (LDPE) from plastic packaging to the surface of the meat samples. The experimental duration of this study was set to be 28 days owing to the selected meat samples’ degradation, which started to become visible to the human eye after 10 days of storage in vacuum LDPE packaging, under refrigerated conditions at 4 °C. Spectroscopic measurements were performed at 0, 3, 9, 12, 15, and 28 days of storage to obtain comparative results. We demonstrated that the Raman spectral peaks of LDPE firstly appeared as a result of polymeric migration on day 9 in Bacon, on day 15 in Salami, and finally on day 28 in Mortadella. On day 28, all meat samples were tainted, with a layer of bacterial outgrowth developed, as proven by bright–field microscopic observation. Food packaging migration to the surface of cured meat samples was validated using Raman vibrational spectroscopy. To ensure minimal consumption of MPs in cured meat products stored in plastic packaging, while at the same time maintaining good food quality, they should be kept in refrigerated conditions and consumed within a short period of time. In this work, the migration of MPs from food packaging to the surface of cured meat samples was observed using micro-Raman spectroscopy. Full article

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13 pages, 11561 KiB

Open AccessArticle

A Practical Valorization Approach for Mitigating Textile Fibrous Microplastics in the Environment: Collection of Textile-Processing Waste Microfibers and Direct Reuse in Green Thermal-Insulating and Mechanical-Performing Composite Construction Materials

by Beatrice Malchiodi, Erika Iveth Cedillo-González, Cristina Siligardi and Paolo Pozzi

Microplastics 2022, 1(3), 393-405; https://doi.org/10.3390/microplastics1030029 - 22 Jul 2022

Cited by 5 | Viewed by 3051

Abstract

Microplastic (MP) contamination is an urgent environmental issue to address. Fibrous microplastics (FMPs) are the principal MP type in the air and have already been found in human stool and lung tissues. FMPs are generated from the lifecycle of synthetic and blended textiles [...] Read more.

Microplastic (MP) contamination is an urgent environmental issue to address. Fibrous microplastics (FMPs) are the principal MP type in the air and have already been found in human stool and lung tissues. FMPs are generated from the lifecycle of synthetic and blended textiles and are expected to increase due to fast fashion. Among textile processes, the finishing of fabrics is estimated to generate 5000 t/year of textile waste fibers in Italy, including FMPs. To limit FMPs spread, this paper suggests, for the first time, the direct collection of blended finishing textile waste microfibers and reuse in designing thermal-insulating and mechanical-performing fiber-reinforced cementitious composites (FRCs). The microfibers were thoroughly characterized (size, morphology, composition, and density), and their use in FRCs was additionally evaluated by considering water absorption and release capacity. Untreated, water-saturated, and NaOH-treated microfibers were considered in FRCs up to 4 wt%. Up to a +320% maximum bending load, +715% toughness, −80% linear shrinkage, and double-insulating power of Portland cement were observed by increasing microfiber contents. NaOH-treated and water-saturated microfibers better enhanced toughness and linear shrinkage reduction. Therefore, green and performant composite construction materials were obtained, allowing for the mitigation of more than 4 kg FMPs per ton of cement paste. This is a great result considering the FMP contamination (i.e., 2–8 kg/day fallout in Paris), and that FRCs are promising and shortly-widely used construction materials. Full article

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16 pages, 2189 KiB

Open AccessReview

End-of-Life of Composite Materials in the Framework of the Circular Economy

by Georgia Chatziparaskeva, Iliana Papamichael, Irene Voukkali, Pantelitsa Loizia, Georgia Sourkouni, Christos Argirusis and Antonis A. Zorpas

Microplastics 2022, 1(3), 377-392; https://doi.org/10.3390/microplastics1030028 - 20 Jul 2022

Cited by 52 | Viewed by 7636

Abstract

Composite materials constitute an appealing choice in many industrial sectors, due to their unique composition and characteristics, such as low maintenance requirements, light weight, corrosion resistance, and durability. However, the sustainable management of end-of-life composite materials remains a challenge. Recovery strategies, design aspects, [...] Read more.

Composite materials constitute an appealing choice in many industrial sectors, due to their unique composition and characteristics, such as low maintenance requirements, light weight, corrosion resistance, and durability. However, the sustainable management of end-of-life composite materials remains a challenge. Recovery strategies, design aspects, and their interconnection are currently largely unexplored, while technologies involved in the circular economy (reuse, reduce, recycle, refurbish, etc.) could be improved. The current paper provides an overview of the existing methods of composite material waste management, while presenting new circular economy prospects for end-of-life strategies and providing a brief roadmap towards circularity for industries. Finally, existing circular economy practices in regard to composites are presented in different European countries to present the applicability of composite material end-of-life waste management. Full article

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2021

Jump to: 2024, 2023, 2022

32 pages, 1310 KiB

Open AccessReview

Governance Strategies for Mitigating Microplastic Pollution in the Marine Environment: A Review

by Amarachi Paschaline Onyena, Donald Chukwudi Aniche, Bright Ogechi Ogbolu, Md. Refat Jahan Rakib, Jamal Uddin and Tony R. Walker

Microplastics 2022, 1(1), 15-46; https://doi.org/10.3390/microplastics1010003 - 2 Dec 2021

Cited by 58 | Viewed by 18139

Abstract

Threats emerging from microplastic pollution in the marine environment have received much global attention. This review assessed sources, fate, and impacts of microplastics in marine ecosystems and identified gaps. Most studies document the ubiquity of microplastics and associated environmental effects. Effects include impacts [...] Read more.

Threats emerging from microplastic pollution in the marine environment have received much global attention. This review assessed sources, fate, and impacts of microplastics in marine ecosystems and identified gaps. Most studies document the ubiquity of microplastics and associated environmental effects. Effects include impacts to marine ecosystems, risks to biodiversity, and threats to human health. Microplastic leakage into marine ecosystems arises from plastic waste mismanagement and a lack of effective mitigative strategies. This review identified a scarcity of microplastics’ mitigation strategies from different stakeholders. Lack of community involvement in microplastic monitoring or ecosystem conservation exists due to limited existence of citizen science and stakeholder co-management initiatives. Although some management strategies exist for controlling effects of microplastics (often implemented by local and global environmental groups), a standardized management strategy to mitigate microplastics in coastal areas is urgently required. There is a need to review policy interventions aimed at plastic reduction in or near coastal ecosystems and evaluate their effectiveness. There is also a need to identify focal causes of microplastic pollution in the marine environment through further environmental research and governance approaches. These would extend to creating more effective policies as well as harmonized and extended efforts of educational campaigns and incentives for plastic waste reduction while mandating stringent penalties to help reduce microplastic leakage into the marine environment. Full article

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