Source Of Microplastics Research Articles

Emergence of microplastics in African environmental drinking water sources: A review on sources, analysis and treatment strategies

The emergence of microplastics (MPs) as microcontaminants in environmental drinking water sources is a problem in Africa that requires immediate action. Therefore, this review focused on understanding the sources of MPs in African water systems, treatment strategies, analytical methods for identification and quantification, and Africa's pollution index. From the findings, the source of MPs in African water systems was attributed to unregulated importation of plastic products, poor waste management, lack of awareness, poor environmental value system and the inability of local polymer industries to adjust to new policies on plastic management. Most studies identified microfibers and microbeads to be the primary sources of plastics that break down to MPs in African drinking water sources, with polystyrene (PS), polypropylene (PP), and polyethylene (PE) being frequently detected. Current methods for identification, and quantification of MPs in most studies conducted in Africa were not developed in Africa but was adopted from developed countries and, in some cases, modified to meet specific analytical requirements. More studies are necessary for in-depth understanding of the fate and pollution index of MP in African environmental water systems. Furthermore, the interaction between MP and other pollutants in the water system still needs to be better understood. This review suggests membrane and rapid sand filtration methods as promising methods that may be considered for removing MPs from water systems in Africa.

Recreational activities as a major source of microplastics in aquatic environments

Recreational activities as a major source of microplastics in aquatic environments

Record of microplastic deposition revealed by ornithogenic soil and sediment profiles from Ross Island, Antarctica

Microplastics (MPs) are a global concern as an emerging pollutant, and the investigation on MPs in Antarctic aids in informing their global pollution assessments. Therefore, there are urgent scientific concerns regarding the environmental behavior, origins, influencing factors, and potential hazards of MPs in Antarctica. This study presents the characteristics of MPs from one ornithogenic sediment profile (coded CC) and two ornithogenic soil profiles (coded MR1 and MR2) from ice-free areas on Ross Island, Antarctica. We explored the potential sources of MPs and the main influencing factors for deposition based on their distribution with depth in the profiles. Through laser-infrared imaging spectroscopy (LDIR), a total of 30 polymer types were identified in all samples, with polyethylene terephthalate (PET) and polyvinyl chloride (PVC) as the dominant types, accounting for more than 70% of the total. The abundance of MPs in the CC sediment profile ranged from 2.83 to 394.18 items/g, while in MR1 and MR2 soil profiles, the abundance ranged from 2.25 to 1690.11 and 8.24 to 168.27 items/g, respectively. The size of MPs was mainly concentrated in the range of 20–50 μm, and possible downward movement of certain polymer types was revealed. From the perspective of temporal variation, we suggest that MPs were heavily influenced by local human activities including scientific research, fishing, and tourism, balanced by protective regulations, while no solid evidence was obtained to support strong influence from biological transport through penguins. This research enhances our understanding on the environmental behavior of MPs in the terrestrial systems of remote polar regions.

Transport and Accumulation of Microplastics from Biosolids to Australian Agricultural Soils: Detection of Microplastics Down to 1 μm.

The shift toward sustainable agriculture involves replacing inorganic fertilizers with organic alternatives like biosolids. However, concerns arise over emerging contaminants, such as microplastics (MPs), which remain largely unregulated. Despite their common use in Australia, the transfer of MPs from biosolids to agricultural soils remains largely unknown. Herein, we have investigated the abundance, characteristics, and transport of MPs resulting from biosolids application in two Queensland agricultural sites. MP concentrations were significantly higher in biosolid-amended soils (average of 1137 MPs/kg) than in reference sites (average of 36 MPs/kg), correlating with the volume, time since application, and frequency of biosolids application. MPs > 25 μm were predominantly polyethylene, polypropylene, and poly(methyl methacrylate) fragments (up to 85%). Fibers constitute only 15-30% of MPs and mainly in larger sizes (average 1011 μm), whereas fragments (average 188 μm) and beads (average 72 μm) had smaller size ranges. Despite analytical challenges using Raman spectroscopy, detected smaller MPs (1-25 μm) were fragments composed of polyethylene, polypropylene, and poly(vinyl alcohol). This study provides the first report of MPs down to 1 μm in Australian agricultural soils. Our findings suggest a need to assess the long-term impact of MPs in biosolids on soil health and food safety. We call on policymakers to consider the implementation of effective MP source control strategies and the development of guidelines for acceptable biosolids application rates.

Microplastic and Nanoplastic in Crops: Possible Adverse Effects to Crop Production and Contaminant Transfer in the Food Chain.

With the increasing amounts of microplastic (MP) deposited in soil from various agricultural activities, crop plants can become an important source of MP in food products. The last three years of studies gave enough evidence showing that plastic in the form of nanoparticles (<100 nm) can be taken up by the root system and transferred to aboveground plant parts. Furthermore, the presence of microplastic in soil affects plant growth disturbing metabolic processes in plants, thus reducing yields and crop quality. Some of the adverse effects of microplastic on plants have been already described in the meta-analysis; however, this review provides a comprehensive overview of the latest findings about possible adverse effects and risks related to wide microplastic occurrence in soil on crop production safety, including topics related to changes of pesticides behavior and plant pathogen spreading under the presence MP and possibly threaten to human health.

Microplastic assessment in remote and high mountain lakes of Gilgit Baltistan, Pakistan

Microplastic (MP) pollution is a critical environmental challenge worldwide, however limited research is reported in remote lakes of Pakistan. This study assessed MPs (>5 mm) prevalence, distribution and risk perspective in water and sediment of eight remote and high-altitude lakes (>1500 m above sea level) of Gilgit Baltistan, Pakistan. The lakes exhibited an average abundance of 152.6 ± 104.6 to 12.1 ± 7 MP/kg of dry sediments and 2 ± 0.9 to 17.1 ± 17.2 MP/L of surface water. MPs <200 μm dominated in both matrices. Surface water predominantly contained polyester and polypropylene, while polypropylene and polyethylene dominated in sediments. The gradient of elevation did not show any pronounced impact on the fiber loading or MP count in both matrices. Backward air mass trajectory revealed that air masses vastly travelled from western-Asia, Arabian sea and Bay of Bengal with an average transmission distance of 2500–3500 km (500 m a.s.l) that can be a potential deposition MP source in the area. Pollution Load Index of the lakes were >1 exhibiting pollution. All other lakes except Batura and Borith manifested a moderate hazard index. Naltar lake along with aforementioned two lakes also manifested high polymer toxicity. Further research should emphasize understanding the mechanisms and biotic interactions in high-mountain ecosystems.

Advanced understanding of the natural forces accelerating aging and release of black microplastics (tire wear particles) based on mechanism and toxicity analysis

Currently, tire wear particles (TWPs), a typical type of black microplastics (MPs), are frequently overlooked as the major source of MPs in aquatic environments. TWPs are widely distributed and exhibit complex environmental behaviors. However, how natural forces affect the aging and release behavior of TWPs at the nano(micro)scale remains inadequately explored. This study systematically investigated the aging behavior and mechanism of TWPs under the action of simulated natural light and high-temperature in both dry and wet environments, as well as the effect of aging treatment on the released leachate. The findings demonstrated that aging treatment significantly altered the physicochemical properties of TWPs, including chain scission and surface oxidation, and facilitated the release of heavy metals and organic additives in the meantime. In particular, the leaching concentration of Zn exhibited a positive linear relationship with exposure time. In the thermal-aging process, the oxidation of TWPs was primarily caused by superoxide anion (O2•−). During the photo-aging exposure, TWPs exhibited heightened electron-donating capacity, resulting in the formation of more O2•− and singlet oxygen (1O2) to attack TWPs. Moreover, the analysis of leachate produced under light and high-temperature conditions suggested that heavy metals exerted low ecological risks in water. Nonetheless, the photo-aging process enhanced the toxicity of released leachate to L929 cells, which could be attributed to highly toxic additive transformation products (such as HMMM-411 and 6PPD-Q) and more heavy metals. These findings shed light on the fate of TWPs and the ecological risks posed by aged TWPs in aquatic environments.

Source identification, characteristics, and spatial distribution of airborne microplastic deposition in Lahore City, Pakistan.

A large volume of atmospheric microplastics (MPs) has been observed worldwide and is considered an emerging global environmental issue. Nevertheless, no significant assessment of the atmospheric deposition of MPs in Pakistan has been reported yet. The present study was designed to highlight the source, type, and spatial distribution of MPs in atmospheric fallout in Lahore, Pakistan. A total of 23 sites were sampled in Lahore with a heterogeneous background of human activities. All samples were collected in a box with a one-foot depth fitted with a steel tray of 0.1 m2 at the bottom. Fenton's reagent and hydrogen peroxide were used to remove organic matter, and sodium chloride for density separation, while the MPs were quantified through a stereomicroscope, and polymers were identified through ATR-FTIR spectroscopy. The highest deposition rate (particles/m2/day) was observed at Badami Bagh, i.e., 6819, followed by Mall Road 4414, and Chung 4263, while the lowest was in Sabzazaar (i.e., 524) and Township (1047) with an average deposition rate of 2340 ± 1392. Among the MPs, the major portion was fiber, i.e., 96%, while fragment was 1.9%, sheets 0.78%, foams 1.12%, beads 0.04%, and other MPs 0.06%. At all sampling sites, 20 different types of polymers were identified with different percentages, of which polyester fibers were predominant with an abundance of 96.09% associated with clothes and textiles. A high frequency of MPs was found in populated areas with dense traffic, plastic wastes, household plastic materials, and mismanagement of wastes, which accelerates the atmospheric deposition of airborne microplastics. Evaluation and characterization of MP help assess health and environmental impacts, cleanup efforts, and guiding regulations. It also provides valuable information for waste management innovation to reduce plastic pollution.

Recent advancement in microplastic removal process from wastewater - A critical review

Microplastics, small sized plastic particles having size <5 mm are formed through primary process including production of beauty products, microbeads and microfibres as well as secondary process including mechanical weathering, friction, aberration and fragmentation of large plastics. The major sources of microplastics are land-based and ocean-based sources. Microplastic pollution is a serious concern due to the persistent, low biodegradability and bio-accumulative behaviour. Microplastics can bioaccumulate in the food chain and can cause ecological and human health risk. Hence, it is important to remove from the aquatic ecosystems. Microplastics are removed from aquatic systems and wastewater through a series of processes such as physical, chemical and biological treatments. In the present articles, >250 articles are reviewed to collect the information regarding the various physical, chemical and biological methods for the removal of microplastics. Also, the probable control strategies to combat with plastic pollution were assessed. It was concluded that recent water treatment methods are efficient in removing microplastic pollution. The efficiencies to remove microplastic from the water ranged between 74 %-99.2 %, 65 %-99.20 % and 77 %-100 % for physical, chemical and biological treatment methods, respectively. Among the three treatment methods, physical methods especially the filtration of water from biochar is the most efficient way (efficiency up to 100 %) to remove microplastics. It was also concluded that creating public awareness, promoting reusing, recycling and reducing, and application of bioplastics can control the production of microplastics from plastic wastes. This review will be useful to add current knowledge regarding the abatement of microplastic pollution, and finding novel solution to control microplastics. This review will also help the policymakers to implement most effective and cost-efficient method to remove microplastics, and to find out new methods to reduce, reuse and recycle plastic wastes.

Fate and drivers of mariculture-derived microplastics from ponds to mangrove forests

Due to the combined influences of marine and terrestrial disturbances, the sources of microplastics (MPs) in mangrove ecosystems are complex and diverse. Previous studies have inferred the possible involvement of mariculture activities as a potential source of mangrove MPs based on the characteristics of MPs. However, the direct contributions of mariculture-derived MPs to mangrove MPs remain largely unknown. In this study, we systematically investigated the fate of MPs in the discharge of mariculture wastewater by quantifying the source contributions of mariculture-derived MPs to rivers and mangroves. The majority of detected MPs were transparent fibers, with their composition primarily comprising materials commonly used in mariculture activities such as polyvinylpyrrolidone (PVP), polyethylene terephthalate (PET), and nylon. The partial least squares path model elucidated the relationships among the composition of MPs in ponds, rivers, and mangroves, indicating that ponds exert a substantial direct effect on mangroves, particularly significant in the sediments (63.68%). Water turbidity, sediment carbon content, and sediment particle size are key ecological factors influencing the abundance of mariculture-derived MPs. This study provides compelling evidence regarding the sources of mangrove MPs and novel insights into mitigating the dissemination of MPs.

Impact of COVID-19 pandemic on microplastic occurrence in aquatic environments: A three-year study in Taihu Lake Basin, China

The impact of the Coronavirus Disease 2019 (COVID-19) pandemic on microplastic (MP) occurrence in aquatic environments deserves an in-depth study. In this study, the occurrence of MPs and environmental flux of plastics before (2019) and during (2020 and 2021) the pandemic were comparatively investigated in various aquatic compartments in the Taihu Lake Basin in China. The field-based investigations from 2019 to 2021 for Taihu Lake have shown that, at the onset of the outbreak, the MP abundance declined at a rate of 62.3 %, but gradually recovered to the pre-pandemic level. However, the amount of plastics being released into aquatic environments showed a declining trend in 2020 and 2021 compared to those in 2019, with decrease rates of 13.7 % and 15.8 %, respectively. Characterization analysis of MP particles and source apportionment framework implied that while the contributions of tire abrasion and domestic waste to MP occurrence were depleted owing to the reduction in human activity during the pandemic, weathering and fragmentation of retained plastics contributed to the recovery of stored MPs. This study provides insights into the anthropogenic influences on MP occurrence, and supports policymakers in managing and controlling plastic contamination in large freshwater systems in the “new normal” phase.

Response of terrestrial crustacean Porcellio scaber and mealworm Tenebrio molitor to non-degradable and biodegradable fossil-based mulching film microplastics

Agricultural mulching films are potential sources of microplastics (MPs) in soil. As an alternative to conventional non-degradable mulching films, a variety of different biodegradable mulching films are used. However, it is not yet known whether MPs from biodegradable mulching films pose a lower risk to terrestrial invertebrates compared to MPs from conventional mulching films. In this study, the effects of MPs produced from two conventional polyethylene (PE-1 and PE-2) and two biodegradable (starch-based poly(butylene adipate co-terephthalate); PBAT-BD-1, and PBAT-BD-2) fossil-based mulching films on terrestrial crustacean woodlice Porcellio scaber and mealworm Tenebrio molitor were compared. A key finding was that no clear differences in induced responses between biodegradable and conventional MPs were detected. No adverse effects on P. scaber after two weeks and on T. molitor after four weeks of exposure were observed up to 5 % (w/w dry soil) of either MP type. However, some sublethal physiological changes in metabolic rate and immune parameters were found in P. scaber after two weeks of exposure indicating a response of organisms to the presence of MP exposure in soil. In addition, it was demonstrated that both types of MPs might affect the soil water holding capacity and pH. In conclusion, we confirmed that biodegradable MPs can induce responses in organisms hence further studies testing the environmental hazard of biodegradable MPs are justified.

Microplastic accumulation in water from protected areas in Western Forest Complex of Thailand

Microplastics (MPs) are emerging as ubiquitous environmental pollutants worldwide. However, no research has been conducted in freshwater ecosystems within Thai protected areas (PAs), where biodiversity and natural resources are safeguarded for human well-being. The aim of this study was to explore the occurrence and abundance of potential MPs in the water of freshwater ecosystems in Thai PAs and to examine factors affecting their presence in the Western Forest Complex in Thailand (WEFCOM). Seventy water samples were collected from eight PAs in WEFCOM using a 20 μm plankton net. The water samples underwent digestion, density separation, and filtration. Potential MPs were visually identified under a stereomicroscope, and their chemical composition was further characterized using FTIR. The results revealed a 98.57 % potential MP prevalence in the water samples, with an average abundance of 0.30 ± 0.32 item·L−1. The quantities of potential MPs among PAs were significantly different (H = 17.88, p = 0.01). Fibers (68.93 %) were the most frequently identified potential MPs, with the dominant colors being blue (22.40 %) and black (20.03 %), mostly small-sized MPs (0.05–0.5 mm; 41.80 %). The major chemical plastic types included low-density polyethylene, polyethylene, polyethylene terephthalate, polypropylene, polyethylene/polypropylene copolymer, polyester, and natural fibers. The abundance of potential MPs varied significantly among PAs, shapes, colors, and sizes (p < 0.01). Furthermore, potential MP abundance correlated with the number of tourists (p < 0.05). Proximity to open waste dumping (p < 0.01) and lower elevation (p < 0.05) tended to accumulate more potential MPs. This research suggests potential sources of microplastics in Thai PAs from wastewater effluent, human activities, and recreational activities, highlighting the urgent need for research to develop appropriate waste management technologies in Thai PAs and to raise awareness among local people and tourists about microplastic pollution.

Using machine learning to reveal drivers of soil microplastics and assess their stock: A national-scale study

The issue of microplastic (MP) contamination in soil is a significant concern. However, due to limited large-scale studies and stock assessments, our understanding of the drivers of their distribution and fate remains incomplete. To address this, we conducted a comprehensive study in China, collected MP data from 621 sites, and utilized machine learning techniques for analysis. Our findings revealed 9 key factors influencing the distribution of soil MPs, highlighting their nonlinear influence processes. Among these factors, atmospheric deposition emerged as the most dominant driver, while wind and precipitation could lead to the transformation of soil from a sink to a source of MPs. MP concentrations in Chinese soils vary from 1.4 to 4333.1 particles/kg, with human activities significantly affecting their distribution, resulting in higher concentrations in the east and lower concentrations in the west. The estimated MP stock in Chinese soils is 1.92 × 1018 particles, equivalent to a mass of 2.11–8.64 million tonnes. This stock alone surpasses that found in global oceans, making global soil the largest reservoir of MPs. Overall, this study enhances our understanding of the environmental behavior of MPs and provides valuable data and theoretical support for the prevention, control, and management of this contamination.

Distribution of microplastics and phthalic acid esters during dry anaerobic digestion of food waste and potential microbial degradation analysis

Food waste (FW) and its biogas residue were considered as sources of terrestrial microplastics (MPs) and phthalic acid esters (PAEs) contamination. However, there was a lack of research and understanding of the MPs and PAEs pollution problem in FW dry anaerobic digestion process (DADP). The MPs and PAEs in three stages of the DADP with the largest monomer disposal scale in China were identified. At the biogas residue extrusion stage, MPs abundance and PAEs concentration reached the highest values, which were 3.63 ± 0.45 × 103 N·kg-1 and 3.62 ± 0.72 mg·kg-1, respectively. Furthermore, there was a significant positive correlation between MPs and PAEs throughout the process (p < 0.05). Although bacteria and fungi with plastic degradation potential were present in all stages, the contamination problem of MPs and PAEs cannot be completely solved through DADP. This study provides a scientific basis for preventing and controlling the pollution of MPs and PAEs.

Microbeads in exfoliating products: occurrence, abundance, and potential for water contamination in Ho Chi Minh City, Vietnam

Microbeads in exfoliating products are a significant source of microplastics entering aquatic ecosystems. This study characterized microbeads in popular facial scrub and body scrub products from Ho Chi Minh City, Vietnam, to quantify abundances and estimate emissions. A selection of facial scrub and body scrub cleansers were collected from local markets and analyzed to quantify microbead properties including the size, color, mass, and abundance of microbeads in the exfoliating cleansers. Results revealed a wide range of microbead sizes (66–1012 μm) and different shapes and colors within and between products. Most contained heterogenous particles of white, green, blue, red, brown, and black spherical microbeads. The range of microbead abundance was 236–942 particles per gram of product. Annual microbead emissions from the use of these products in Ho Chi Minh City were estimated based on population and usage data. The total annual emission of microbeads from facial and body scrubs in Ho Chi Minh City amounted to 1.3 billion microbeads. On a per capita basis, this equaled 880 microbeads per person annually discharged into the local water environment. According to the study, a preliminary calculation indicated that approximately 2640 microbeads were released per year per female student in Ho Chi Minh City. By providing an initial ssessment of microbead pollution arising specifically from personal care items in Vietnam, this study raises awareness of microplastics introduction into Asian coastal zones via cosmetic products. The baseline data establishes a foundation for further investigations. This represents an important step in quantifying and addressing an emerging microplastic source in the region.

Point and nonpoint sources of microplastics to two Southeast Michigan rivers and reduced biofilm function on plastic substrata

Point and nonpoint sources of microplastics to two Southeast Michigan rivers and reduced biofilm function on plastic substrata

Quantification and characterization of microplastics ingested by mangrove oysters across West Africa

Microplastic ingestion by marine organisms presents a challenge to both ecosystem functioning and human health. We characterized microplastic abundance, shape, size, and polymer types ingested by the West African mangrove oyster, Crassostrea tulipa (Lamarck, 1819) sampled from estuaries and lagoons from the Gambia, Sierra Leone, Ghana, Benin, and Nigeria using optical microscopy and Fourier transform infrared (FTIR) techniques. A total of 780 microplastics were isolated in the whole tissues of the 250 oysters (n = 50 oysters per country). The abundance and distribution of microplastics in the oysters followed the pattern: the Gambia > Ghana > Sierra Leone > Nigeria > Benin. The Tanbi wetlands in the Gambia recorded the highest average of 10.50 ± 6.69 per oyster while the Ouidah lagoon in Benin recorded the lowest average of 1.80 ± 1.90 per oyster. Overall, microplastic numbers varied significantly (p < 0.05) among the five countries. Microfibers, particularly those within 1001–5000 μm size, dominated the total microplastic count with a few fragments and films. No spherical microplastics were isolated in the oysters. In the Sierra Leone and Benin oysters, fragments and films were absent in the samples. Microplastic between the 1001 and 5000 μm size class dominated the counts, followed by 501–1000 μm, 101–500 μm, and 51–100 μm. Five polymer groups namely polyethylene, polyester, nylon, polypropylene, and polyamide were identified across the five countries, with polyethylene occurring in oysters from all five countries and polyester occurring in all but the oysters from Nigeria. This diversity of polymers suggests varied sources of microplastics ingested by the studied oysters. The absence of microspheres across the five supports findings from other studies that they are the least ingested and highly egested by the oysters.Graphical

Tracking and risk assessment of microplastics in a wastewater treatment plant

AbstractToday, microplastics have become one of the most important environmental concerns. Wastewater treatment plants are a major source of microplastics in the environment. The aim of this study is to track and assess the risk of microplastics in a wastewater treatment plant. Samples were taken from different units of sewage treatment plants in the spring and winter. Microplastics were separated using sieves and density‐based methods. Analysis revealed a higher abundance of microplastics in spring. The highest amount of microplastic removal was in the disinfection and secondary sedimentation units in the winter season. Fragments are the most common shape. Poly Ethylene Terephthalate (PET) polymers were most prevalent. Black was the most common colour. Poly Ethylene (PE), PET and poly Amide (PA) polymers posed the highest risk, according to calculations. One of the most important ways to prevent microplastics from entering water sources is to reduce the consumption of plastic materials, recycle plastic waste and remove microplastics from the wastewater treatment process.

From cosmetics to Contamination: Microplastics in personal care products as vectors for chromium in aquatic environments

Microplastics presence in the environment is now a major global issue. Personal care and cosmetic products (PCCPs) contain microbeads and are one of the primary sources of microplastics which contribute to health and ecological risks. The aim of this study was to evaluate the presence of microbeads in a widely used PCCPs (facial scrubs) in the Indian market and the extent to which these microbeads can serve as vectors for toxic compounds like chromium under different environmental conditions. Four of the ten facial scrubs contained microbeads of size ranging from 220 to 600 µm. Based on FTIR analyses, two of the four tested samples (A and B) were made of polypropylene, while the other two samples (C and D) were made of polyethylene. Furthermore, the study revealed that PP microbeads, which are very common, could efficiently adsorb Cr (VI) (3.09 mg Cr/g). Adsorption of Cr (VI) on microbeads was greater in acidic and saline conditions indicating that microbeads can potentially act as vectors for toxic compounds in marine aquatic ecosystems. It was estimated that 4.7 x 1010 microbeads, which amount to 3.8 tonnes of microbeads are released into the environment annually. Based on these results, policy measures for preventing the release of microbeads/microplastics into the environment are suggested.