Detection in influx sources and estimation of microplastics abundance in surface waters of Rawal Lake, Pakistan

Charting the microplastic menace: A bibliometric analysis of pollution in Malaysian mangroves and polypropylene bioaccumulation assessment in Anadara granosa

According to a bibliometric analysis, studies on microplastic pollution in Malaysia are still incomprehensive. This study found microplastic contamination in sediment (97 particles/kg) and water (10,963 particles/m3) samples from Malaysian mangroves. Sediment from Matang and water from Kuala Selangor recorded the highest microplastic concentrations at 140 ± 5.13 particles/kg and 13,350 ± 37.95 particles/m3, respectively. Fragmented, blue, rayon and particles of <0.1 mm microplastic were the most abundant in sediment and water. In an experiment of polypropylene microplastic uptakes, Anadara granosa was found to uptake more 0.1 mm fiber particles. The uptake is strongly correlated to the presence of microplastics in sediment and water. The estimated dietary intake (EDI) indicates that a consumer could ingest 507 microplastic particles/year by consuming contaminated A. granosa. Therefore, mitigating measures are crucial to safeguard aquatic systems and humans from microplastic pollution.

Unveiling the ecotoxicological impact of microplastics on organisms - the persistent organic pollutant (POP): A comprehensive review

Microplastics have been ubiquitous in our environment for decades, and numerous studies have revealed their extensive dispersion, reaching far beyond the surface of the land, soil, aquatic ecosystems. They have infiltrated the food-chain, the food web, even the air we breathe, as well as the water we drink. Microplastics have been detected in the food we consume, acting as vectors for hazardous chemicals that adhere to their hydrophobic surfaces. This can result in the transfer of these chemicals to the aquatic life, posing a threat to their well-being. The release of microplastics into different environmental settings can give rise to various eco-toxicological implications. The substantial body of literature has led scientists to the consensus that microplastic pollution is a global problem with the potential to impact virtually any type of ecosystem. This paper aims to discuss crucial information regarding the occurrence, accumulation, and ecological effects of microplastics on organisms. It also highlights the new and emerging disease named "Plasticosis" that is directly linked to microplastics and its toxicological effects like permanent scarring and long-term inflammation in the digestive system of the seabirds. By comprehending the behaviour of these microplastic pollutants in diverse habitats and evaluating their ecological consequences, it becomes possible to facilitate a better understanding of this toxicological issue.

Beneath the surface: Exploring microplastic intricacies in Anadara granosa

Anadara granosa or blood cockles have been reported to be a candidate for biomonitoring agents due to their sedimentary nature and their nutrient uptake mechanisms. Yet, this bivalve is still regarded as a delicacy in Asian cuisine. Malaysia is the largest exporter of this sea product that contaminated cockles may also be experienced by the importing countries. However, the bioaccumulation of microplastics in A. granosa cultivated in Malaysia has not been extensively studied. It is crucial to comprehend the risk posed to humans by consuming A. granosa in their diet. Therefore, the purpose of this research is to investigate the levels of microplastic accumulation in A. granosa from major exporters in Peninsular Malaysia, to evaluate the associated risk of microplastics on the species, and to estimate daily human consumption of microplastics through the consumption of A. granosa. The abundance of microplastics was quantified through the use of a stereo microscope, and the polymer type was determined using FTIR and micro-FTIR. Findings from this investigation revealed that all samples of A. granosa were contaminated with microplastics, with the highest levels of accumulation found in bivalves collected from the west coast (0.26 ± 0.15 particles/g) of Peninsular Malaysia. Fragment and fiber microplastics, measuring between 0.05 and 0.1 mm in size, were found to be the most prevalent in A. granosa, with blue being the dominant identified colour and rayon being the most common polymer type. Microplastic risk assessment due to the presence of polyacrylate, polycarbonate (PC), and polymethyl methacrylate (PMMA) resulted in a high risk of contamination for A. granosa. It was further determined that the current estimated dietary intake (EDI) suggests that consumers of A. granosa uptake approximately 21.8-93.5 particles/person/year of microplastics. This study highlights that A. granosa accumulates microplastics, which could potentially result in bioaccumulation and biomagnification in humans through consumption.

Unveiling microplastics pollution in a subtropical rural recreational lake: A novel insight

While global attention has been primarily focused on the occurrence and persistence of microplastics (MP) in urban lakes, relatively little attention has been paid to the problem of MP pollution in rural recreational lakes. This pioneering study aims to shed light on MP size, composition, abundance, spatial distribution, and contributing factors in a rural recreational lake, 'Nikli Lake' in Kishoreganj, Bangladesh. Using density separation, MPs were extracted from 30 water and 30 sediment samples taken from ten different locations in the lake. Subsequent characterization was carried out using a combination of techniques, including a stereomicroscope, Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FE-SEM). The results showed a significant prevalence of MPs in all samples, with an average amount of 109.667 ± 10.892 pieces/kg3 (dw) in the sediment and 98.167 ± 12.849 pieces/m3 in the water. Small MPs (<0.5 mm), fragments and transparent colored particles formed the majority, accounting for 80.2%, 64.5% and 55.3% in water and 78.9%, 66.4% and 64.3% in sediment, respectively. In line with global trends, polypropylene (PP) (53%) and polyethylene (PE) (43%) emerged as the predominant polymers within the MPs. MP contents in water and sediment showed positive correlations with outflow, while they correlated negatively with inflow and lake depth (p > 0.05). Local activities such as the discharge of domestic sewage, fishing waste and agricultural runoff significantly influence the distribution of polypropylene. Assessment of pollution factor, pollution risk index and pollution load index values at the sampling sites confirmed the presence of MPs, with values above 1. This study is a baseline database that provides a comprehensive understanding of MP pollution in the freshwater ecosystem of Bangladesh, particularly in a rural recreational lake. A crucial next step is to explore ecotoxicological mechanisms, legislative measures and future research challenges triggered by MP pollution.

Current patterns and trends of microplastic pollution in the marine environment: A bibliometric analysis

Microplastics are pervasive in the natural environment and pose a growing concern for global health. Plastic waste in marine environments has emerged as a global issue, threatening not only marine biota but also human health due to its implications for the food chain. This study aims to discern the patterns and trends of research, specifically on Marine Microplastic Pollution (MMP), based on a bibliometric analysis of scientific publications from 2011 to 2022. The methodology utilized in this study comprises three stages: (a) creating a bibliographical dataset from Scopus by Elsevier and the Web of Science Core Collection by Clarivate Analytics, (b) analyzing current research (trends and patterns) using bibliometric analysis through Biblioshiny tool, and (c) examining themes and subthemes in MMP research (wastewater treatment, plastic ingestion, the Mediterranean Sea, microplastics pollution, microplastics in freshwater, microplastic ingestion, plastic pollution, and microplastic pollution in the marine environment). The findings reveal that during the studied period, the number of MMP publications amounted to 1377 articles, with an average citation per publication of 59.23 and a total citation count of 81,553. The most cited article was published in 2011, and since then, the number of publications on this topic has been increasing steadily. The author count stood at 5478, with 22 trending topics identified from the 1377 published titles. Between 2019 and 2022, the countries contributing most to the publication of MMP articles were China, the United States of America (USA), and the United Kingdom (UK). However, a noticeable shift in the origin of author countries was observed in the 2019-2022 timeframe, transitioning from a dominance by the USA and the UK to a predominance by China. In 2019, there was a substantial increase in the volume of publications addressing the topic of microplastics. The results show that the most prevalent themes and subthemes pertained to MMP in the Mediterranean Sea. The journals with the highest number of MMP articles published were the Marine Pollution Bulletin (253 articles) and Science of the Total Environment (190 articles). The analysis concludes that research on MMP remains prominent and appears to be increasing each year.

Occurrence and distribution of microplastics in the adjacent environment of Yellow River Delta, China

In the precent study, the microplastics (MPs) pollution level was evaluated in diverse environmental samples from the Yellow River Delta. The results indicated that the abundance of MPs in water, sediment and soil samples ranged from 0.50 to 7.83 items·L-1, 200 to 4200 items·kg-1, and 100 to 1400 items·kg-1, respectively. Film form of MPs was dominant in water, while fiber MPs were dominant in both sediment and soil samples. In all samples, most MPs were < 1 mm in size. White was the main color in water, black was the main color in sediment and soil samples. The most common MPs type was polyethylene (33 %) in water, while rayon accounted for the majority of MPs in sediment (42 %) and soil (70 %) samples. The redundancy analysis results showed that MPs in water and sediment were more affected by water quality, while soil MPs were easily affected by landscape pattern.

A review of microplastic threat mitigation in Asian lentic environments

Microplastic (MP) pollution has evolved into a significant worldwide environmental concern due to its widespread sources, enduring presence, and adverse effects on lentic ecosystems and human well-being. The growing awareness of the hidden threat posed by MPs in lentic ecosystems has emphasized the need for more in-depth research. Unlike marine environments, there remain unanswered questions about MP hotspots, ecotoxic effects, transport mechanisms, and fragmentation in lentic ecosystems. The introduction of MPs represents a novel threat to long-term environmental health, posing unresolved challenges for sustainable management. While MP pollution in lentic ecosystems has garnered global attention due to its ecotoxicity, our understanding of MP hotspots in lakes from an Asian perspective remains limited. Hence, the aim of this review is to provide a comprehensive analysis of MP hotspots, morphological attributes, ecotoxic impacts, sustainable solutions, and future challenges across Asia. The review summarizes the methods employed in previous studies and the techniques for sampling and analyzing microplastics in lake water and sediment. Notably, most studies concerning lake microplastics tend to follow the order of China > India > Pakistan > Nepal > Turkey > Bangladesh. Additionally, this review critically addresses the analysis of microplastics in lake water and sediment, shedding light on the prevalent net-based sampling methods. Ultimately, this study emphasizes the existing research gaps and suggests new research directions, taking into account recent advancements in the study of microplastics in lentic environments. In conclusion, the review advocates for sustainable interventions to mitigate MP pollution in the future, highlighting the presence of MPs in Asian lakes, water, and sediment, and their potential ecotoxicological repercussions on both the environment and human health.

New insights into the migration, distribution and accumulation of micro-plastic in marine environment: A critical mechanism review

Microplastics (MPs) are widely distributed in the marine environment, posing a significant threat to marine biota. The contribution of anthropogenic and terrestrial sources to the aquatic ecosystem has led to an increase in MPs findings, and their abundance in aquatic biota has been reported to be of concern. MPs are formed mainly via photo degradation of macroplastics (large plastic debris), and their release into the environment is a result of the degradation of additives. Eco-toxicological risks are increasing for marine organisms, due to the ingestion of MPs, which cause damage to gastrointestinal (GI) tracts and stomach. Plastics with a size <5 mm are considered MPs, and they are commonly identified by Raman spectroscopy, Fourier transfer infrared (FTIR) spectroscopy, and Laser direct infrared (LDIR). The size, density and additives are the main factors influencing the abundance and bioavailability of MPs. The most abundant type of MPs found in fishes are fiber, polystyrenes, and fragments. These microscale pellets cause physiological stress and growth deformities by targeting the GI tracts of fishes and other biota. Approximately 80% MPs come from terrestrial sources, either primary, generated during different products such as skin care products, tires production and the use of MPs as carrier for pharmaceutical products, or secondary plastics, disposed of near coastal areas and water bodies. The issue of MPs and their potential effects on the marine ecosystem require proper attention. Therefore, this study conducted an extensive literature review on assessing MPs levels in fishes, sediments, seawater, their sources, and effects on marine biota (especially on fishes), chemo-physical behavior and the techniques used for their identification.

Research status and prospects of microplastic pollution in lakes

As an emerging pollutant, microplastics have attracted widespread concern around the world. Research on microplastics was first conducted in oceans, and in recent years, inland water, especially lakes, has gradually become a hot spot. This paper systematically reviews the sampling, separation, purification, and identification technologies used to assess microplastics in lakes and summarizes the occurrence of lake microplastics worldwide. The results show that microplastics are widespread in lake water and sediment. There are obvious geographical differences in the occurrence of microplastics. The abundance of microplastics in different lakes varies greatly. The forms are mostly fibrous and fragments, and the main polymers are polypropylene (PP) and polyethylene (PE). Previous papers have failed to comment in as much detail on the microplastic sampling techniques employed within lake systems. The sampling and analysis methods are critical to accurately evaluating contamination results. Due to the widespread presence of microplastics and the lack of uniform standards, there are various sampling methods. Trawls and grabs are most widely used in the sampling of lake water bodies and sediment, and sodium chloride and hydrogen peroxide are the most widely used media for flotation and digestion, respectively. In the future, it will be critical to establish unified standards for lake microplastic sampling and analysis technology, further explore the migration mechanism of microplastics in lake systems, and pay attention to the impact of microplastics on lake ecosystems.

Polystyrene microparticles can affect the health status of freshwater fish - Threat of oral microplastics intake

Plastic waste pollution is considered one of the biggest problems facing our planet. The production and use of these materials has led to huge amounts of plastic waste entering the aquatic environment and affecting aquatic life. In our experiment, the effect of polystyrene microparticles (PS-MPs; 52.5 ± 11.5 μm) on individual juvenile rainbow trout (Oncorhynchus mykiss) was tested at three different dietary concentrations of 0.5, 2 and 5 % for six weeks. At the end of the experiment, various health parameters of exposed organisms were compared with the control group. The haematological profile revealed an immune response by a decrease in lymphocyte count with a concurrent increase in the number of neutrophil segments at the highest concentration of PS-MPs (5 %). Biochemical analysis showed significant reductions in plasma ammonia in all tested groups, which may be related to liver and gill damage, as determined by histopathological examination and analysis of inflammatory cytokines expression. In addition, liver damage can also cause a significant decrease in the plasma protein ceruloplasmin, which is synthesized in the liver. PS-MPs disrupted the antioxidant balance in the caudal kidney, gill and liver, with significant changes observed only at the highest concentration. In summary, PS-MPs negatively affect the health status of freshwater fish and represent a huge burden on aquatic ecosystems.

Pollution and Distribution of Microplastics in Grassland Soils of Qinghai-Tibet Plateau, China

Microplastics (MPs) are plastic fragments with particle sizes smaller than 5 mm that have potentially harmful effects on ecosystems and human health. The soil environment is not only the source but also the sink of MPs. Thus, it is necessary to fully understand the pollution and distribution of MPs in soils. In this study, Qinghai Province, northeast of the Qinghai-Tibet Plateau, was selected as the research area, and 22 soil samples were collected and analyzed to study the levels and distribution characteristics of MPs in grassland soils. MPs were obtained from the soils by using density separation, and a laser confocal micro Raman spectrometer was used for MP identification. The results showed that MPs were detected in all of the soil samples. The total abundances of MPs ranged from 1125 to 1329 items/kg, with a mean abundance of 1202 items/kg. Various types, shapes, sizes, and colors of MPs were observed. Polyethylene terephthalate (PET) was the dominant polymer in all the grassland soil samples. The size range of 10-50 μm accounted for 50% of all identified MPs. Pellets were the dominant MP shape, and colored MPs accounted for 64% of all MPs. The results revealed the presence of large quantities of MPs in the grassland soils of remote areas as well. This study can act as a reference for further studies of MPs in terrestrial systems. At the end of the paper, the prospects and suggestions for pollution control by soil MPs are given.

Comprehensive analysis of spatial distribution of microplastics in Rawal Lake, Pakistan using trawl net and sieve sampling methods

Occurrence of microplastics (MPs) in freshwater environments, particularly reservoir and lakes, is an emerging concern. There are limited studies in Pakistan on microplastic pollution in the lacustrine environments and those that exist do not provide sufficient information on the spatial distribution of MPs in offshore surface water. The aims of this study were to determine microplastic abundance in Rawal Lake, Pakistan and to ascertain if sampling methodology influences microplastic counts. Surface water samples were collected from 10 sites; 5 tributaries, 2 human settlement and 3 fishing and boating areas using two different sampling techniques: 100 μm mesh trawl and 20 L sample through a 45 μm mesh sieve. A significant difference was observed in the abundance of MPs across two methods with the sieve method yielding 2.8 ± 1.44 particles/L and trawl yielding 0.025 ± 0.024 particles/L. Tributaries and boating/fishing area had higher microplastic abundance than the residential area regardless of sampling method. Filaments were the dominant shape of MPs in both type of samples followed by fragments in trawl samples and films in sieved samples. Microbeads were only detected in trawl samples. MPs within size range 0.1-0.9 mm were mostly fragments (82%). MPs were diverse in colors with white/transparent and black MPs common. Polypropylene was the main type of microplastic in Rawal Lake (40-74%). Scanning Electron Microscopy (SEM) of MPs showed cracks, roughness and striations on the particles. Energy Dispersive Spectroscopy (EDS) detected heavy metals (Fe, Cu, Ni, Pb, Zn, Co and Cr) in MPs. Findings suggest that microplastic pollution in Rawal Lake may pose great risk to aquatic and human life through leaching of inherent/adsorbed heavy metals and therefore requires future investigation.

Microplastic pollution in the surface water and sediments from Kallar Kahar wetland, Pakistan: occurrence, distribution, and characterization by ATR-FTIR

This study reports the distribution of microplastics in surface water and sediments collected from Kallar Kahar wetland, Punjab, Pakistan, which is a game reserve and hosts migratory birds during winter season. Microplastics were extracted using density separation and wet oxidation method. The microplastics identification was done under a stereo-microscope, and their polymer compositions were characterized using an attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The average abundance of microplastics in water and sediment samples was 88 ± 14.5 items/L and 5720 ± 2580 items/kg, respectively. The dominant shape groups of microplastics in water were fiber (58.7%), irregular fragments (32.4%), and beads (8.7%) with dominant colors as transparent > black > yellow ≈ white > red > green > pink > blue. Similar distribution in sediments was found, i.e., fiber (61.2%), irregular fragments (28.4%), and beads (10.3%) with dominant colors as transparent > pink > white > red ≈ black > blue > brown > green ≈ yellow. The ATR-FTIR spectra of visible microplastics were identified to be polypropylene (PP), high density polyethylene (HDPE), ethylene vinyl acetate (EVA), low density polyethylene (LDPE), nitrile, polymethyl methacrylate (PMMA), latex, and polyethylene terephthalate (PETE). In the study area, recreational activities, improper waste disposal, and runoff from catchment areas are the main reasons for the contamination of microplastics in the Lake. The pollution load can be minimized by taking measures such as creating awareness, promotion of ecotourism, and reducing plastic use.