Microplastics ingestion by blue panchax fish (Aplocheilus sp.) from Ciliwung Estuary, Jakarta, Indonesia

From riverbank to the sea: An initial assessment of plastic pollution along the Ciliwung River, Indonesia

This study presents the first comprehensive analysis of anthropogenic debris on the riverbanks of the Ciliwung River, covering upstream to downstream areas. The mean of debris found in each measurement was 32.79 ± 15.38 items/m2 with a weight of 106.00 ± 50.23 g/m2. Plastic debris accounted for over 50 % of all litter items identified and represents 55 % by weight, signifying a significantly high prevalence compared to global studies examining litter along riverbanks. The majority of the plastics found originated from Single-use applications and were predominantly made from Styrofoam. This investigation demonstrated the importance of actions to reduce single use applications and to improve waste management strategies. This can be achieved through proactive initiatives coupled with adaptable approaches, such as implementing effective urban planning and enhancing waste collection capacity.

Microplastics in Indonesian land and aquatic environment: From research activities to regulation policies

Indonesia is suspected as one of the largest plastic waste contributors to the ocean, resulting in microplastic (MP) contamination of the marine environment. Likewise, >250 MP research in Indonesia have been published in the last decade, including review articles. However, a comprehensive review covering MP observations in all areas, i.e. land, freshwater, and ocean, and the regulation aspect in Indonesia remains unexplored. This review finds that the current MP studies are not sufficient to provide the big picture of MP distribution in Indonesia, suggesting the need for research guidelines and coordination among scholars in this field. In addition, the currently implemented local regulation in plastic item limitation should be supported by effective monitoring, sanction, and education for citizens, as well as investment in waste management facilities. Overall, this review suggests the improvement of MP studies and national regulation as countermeasures for MP pollution problems.

Organ-specific bioaccumulation of microplastics in market fish of Dhaka and size-dependent impacts of PVC microplastics on growth of Anabustestudineus

Microplastics (MPs), a growing environmental concern with potential ecotoxicological risks, are ubiquitous in aquatic environment. This study investigated the organ-specific distribution and variation of MPs in commercially caught fishes (7 species, 140 individuals) collected from Dhaka's two main fish distribution hubs (Uttara and Jatrabari). Additionally, the impact of different-sized MPs on fish growth (Anabas testudineus) was examined in a control experiment. Results revealed that kidneys of market fish bioaccumulated the highest concentration of MPs (average, 59.1 MPs/g), followed by liver (24.6 MPs/g) and intestine (18.6 MPs/g). On average, fish from Uttara had a higher MPs concentration (36 MPs/g) compared to Jatrabari (25 MPs/g). Among fish species, Glossogobius giuris showed the highest MPs bioaccumulation due to its feeding habits and morphology. Fiber-shaped MPs were most prevalent in all fishes (79-93%) except Glossogobius giuris (fragments, 51%). Fourier-transform infrared spectroscopy (FTIR) analysis identified 19 different polymer types, with high density polyethylene (HDPE), ethylene vinyl acetate (EVA) and polyamide (PA) being commonly found in all organs. The experimental study confirmed that large-sized PVC MPs (1.18 mm-300 μm) had a greater negative impact on fish growth (length) and caused more physical deformities (particularly intestinal injuries) compared to small-sized PVC MPs (150 μm-75 μm). Moreover, fish exposed to larger diameter MPs experienced highest physical weight and depth loss among exposed groups. Large-sized PVC MPs bioaccumulated highest in fish compared to small-sized PVC MPs. Similar to market fish, kidney in the experimental fish had the highest MPs bioaccumulation (6.5 MPs/g), followed by liver (5.2 MPs/g) and intestine (4.8 MPs/g), with a dominance of fibers despite the presence of high concentration of fragments in the food source. Statistical analysis also supported a clear correlation between increasing MPs size and adverse effects on fish growth and health. Urgent action is needed to curb microplastic pollution and protect ecosystems and human health.

Macroalgae Bioplastics: A Sustainable Shift to Mitigate the Ecological Impact of Petroleum-Based Plastics

The surge in global utilization of petroleum-based plastics, which notably heightened during the COVID-19 pandemic, has substantially increased its harm to ecosystems. Considering the escalating environmental impact, a pivotal shift towards bioplastics usage is imperative. Exploring and implementing bioplastics as a viable alternative could mitigate the ecological burden posed by traditional plastics. Macroalgae is a potential feedstock for the production of bioplastics due to its abundance, fast growth, and high cellulose and sugar content. Researchers have recently explored various methods for extracting and converting macroalgae into bioplastic. Some of the key challenges in the production of macroalgae bioplastics are the high costs of large-scale production and the need to optimize the extraction and conversion processes to obtain high-quality bioplastics. However, the potential benefits of using macroalgae for bioplastic production include reducing plastic waste and greenhouse gas emissions, using healthier materials in various life practices, and developing a promising area for future research and development. Also, bioplastic provides job opportunities in free enterprise and contributes to various applications such as packaging, medical devices, electronics, textiles, and cosmetics. The presented review aims to discuss the problem of petroleum-based plastic, bioplastic extraction from macroalgae, bioplastic properties, biodegradability, its various applications, and its production challenges.

Microplastics in the Volta Lake: Occurrence, distribution, and human health implications

Pollution of plastic waste in aquatic ecosystems in Ghana is of significant concern with potential adverse effects on food safety and ecosystem function. This study examined the abundance and distribution of microplastics (MPs) in freshwater biota samples namely: the African river prawn (Macrobrachium vollenhovenii), the Volta clam (Galatea paradoxa), Nile tilapia (Oreochromis niloticus), and sediment from the Volta Lake. Both biota and sediment samples were subjected to microscopic identification and FTIR analysis. In biota samples, the highest mean microplastic abundance of 4.7 ± 2.1 items per individual was found in the prawn, while the Nile tilapia recorded the least (2.8 ± 0.6 items per individual). A total of 398 microplastic particles were observed in sediment samples from the Volta Lake. Microfibers were the major plastic shapes identified in biota and sediment samples. We examined the relationship between microplastic abundance, biota size, and sediment properties. Despite the lack of statistical significance, microplastic shape, size, and polymer composition in assessed organisms mirrored those in the benthic sediment. Polyethylene, polypropylene, polyester, and polystyrene were the four dominant polymer types identified in the organisms and sediments. Although the estimated human exposure was relatively low compared with studies from other regions of the world, the presence of microplastics raises concern for the safety of fisheries products consumed by the general populace in the country. This research is essential for developing effective mitigation measures and tackling the wider effects of microplastic contamination on Ghana's freshwater ecosystems, particularly the Volta Lake.

Vertical distribution of microplastic along the main gate of Indonesian Throughflow pathways

Even though Pacific - Indian Ocean exchange [Indonesian Throughflow (ITF)] has been measured for the last three decades, the measurements of microplastic in the region is very limited. This study was the initial investigation of the vertical distribution of microplastic in the deep-sea areas across the ITF Pathway. Niskin water samples were utilized to obtain the samples from a water column in a range of 5 to 2450 m. A total of 924 microplastic particles with an average abundance of 1.062 ± 0.646. n/L were found in the water column. Our findings indicate that water temperature and water density are the most significant factors correlated to the microplastic concentration. This study will be the first report discussing the distribution of microplastics in the deep-sea water column that could be highly significant in determining the fate and transport of microplastic within Indonesian waters that exits into the Indian Ocean.

Abundance and characterization of microplastic pollution in the wildlife reserve, Ramsar site, recreational areas, and national park in northern Jakarta and Kepulauan Seribu, Indonesia

This is the first study to evaluate the presence and distribution of microplastics in sediments in the regions with a unique degree of complexity, such as wildlife reserve areas, a Ramsar site that connects directly to Greater Jakarta's mainland, recreational islands, and a marine national park. Microplastics of varying sizes and shapes are found in all places, with an increase trend in the abundance toward areas near to the epicenter of human activity. Comparatively to other marine protected areas, the amount of microplastics discovered is comparable; however, there is an upward trend. Season influences microplastic accumulation, with the dry season causing the greater accumulation. Small-sized microplastics and microplastics resulting from large plastic fragments were predominantly discovered. The properties of microplastics in the study region are dominated by polyethylene, polypropylene, polystyrene, polyvinyl chloride, and nylon. Additional in-depth research and waste reduction from all sources that involve all stakeholders are required to reduce the amount of contaminants entering the protected area.

Microplastic contamination in the digestive tract of sea urchins (Echinodermata: Echinoidea) in Kepulauan Seribu, Indonesia

The accumulation of microplastics on sediment surfaces contributed to the digestive tract of sea urchins contamination during foraging. Therefore, the aim of this study was to investigate the potential relationship between the accumulation of microplastics on sediment surfaces and the contamination of sea urchins' digestive tracts during their foraging activities. Sediment and sea urchins' samples were collected from Pari and Harapan Islands, in Kepulauan Seribu, DKI Jakarta, Indonesia. Microplastics were extracted and observed in sediment and the digestive tract of sea urchins' samples. Fourier transform infrared (FTIR) spectroscopy identified microplastic polymers. The average microplastic concentration on Pari Island was 160 ± 158.75 particles/kg dry weight sediment and 3.93 ± 2.25 particles/g dry weight in the digestive tract of sea urchins. Correspondingly, on Harapan Island, the values were 113 ± 41.63 particles/kg dry weight and 0.27 ± 0.28 particles/g dry weight. Fragment-type microplastics (75%) were predominantly detected in the digestive tract of sea urchins, while fiber-type microplastics (59%) were more common in sediments on Pari Island. Conversely, on Harapan Island fragment types were more prevalent (53%). Microplastics larger than 1000 µm were identified in both sediment and the digestive tract of sea urchins. The observed plastic polymers, such as polyethylene, polyester, and polypropylene were dominant at both study sites. This study postulated that microplastics in sediments may be ingested during sea urchins digestion, supported by a significant correlation of 0.016. Consequently, the presence of microplastics in sea urchins from Pari Island and Harapan Island in Kepulauan Seribu was confirmed. Future investigations should explore the toxic effects of absorbed microplastics on sea urchins' physiology, requiring further analysis.

Is Zooplankton an Entry Point of Microplastics into the Marine Food Web?

Microplastics (MPs) overlap in size with phytoplankton and can be ingested by zooplankton, transferring them to higher trophic levels. Copepods are the most abundant metazoans among zooplankton and the main link between primary producers and higher trophic levels. Ingestion of MPs has been investigated in the laboratory, but we still know little about the ingestion of MPs by zooplankton in the natural environment. In this study, we determined the concentration and characteristics of MPs down to 10 μm in zooplankton samples, sorted calanoid copepods, and fecal pellets collected in the Kattegat/Skagerrak Sea (Denmark). We found a median concentration of 1.7 × 10-3 MPs ind-1 in the zooplankton samples, 2.9 × 10-3 MPs ind-1 in the sorted-copepods, and 3 × 10-3 MPs per fecal pellet. Most MPs in the zooplankton samples and fecal pellets were fragments smaller than 100 μm, whereas fibers dominated in the sorted copepods. Based on the collected data, we estimated a MP budget for the surface layer (0-18 m), where copepods contained only 3% of the MPs in the water, while 5% of the MPs were packed in fecal pellets. However, the number of MPs exported daily to the pycnocline via fecal pellets was estimated to be 1.4% of the total MPs in the surface layer. Our results indicate that zooplankton are an entry point of small MPs in the food web, but the number of MPs in zooplankton and their fecal pellets was low compared with the number of MPs found in the water column and the occurrence and/or ingestion of MPs reported for nekton. This suggests a low risk of MP transferring to higher trophic levels through zooplankton and a quantitatively low, but ecologically relevant, contribution of fecal pellets to the vertical exportation of MPs in the ocean.

Study of feeding biology and diet-associated microplastic contamination in selected creek fishes of northeastern Arabian Sea: A multi-species approach

This study investigated the diet composition and microplastic contamination in six fish species collected from the creek area of northeastern Arabian Sea. The results show that the diet of the fish is mainly composed of shrimps, algae, fish, and zooplankton, with microplastics constituting up to 4.83 % (Index of Preponderance) of their diet. The average abundance of microplastics ranges from 5.82 to 7.69 items per fish, and their ingestion is influenced by seasonal variation, gut fullness, and trophic level. Microplastic contamination has no significant effect on the condition factor and hepatosomatic index of the fish species. However, polymer hazard index indicates that microplastic pollution in fish is associated with a low to high risk factor, which might cause potential harm to aquatic lives and higher vertebrates via food chain. Therefore, this study highlights the need for immediate attention and effective regulations to reduce microplastic pollution to protect marine life.

Euryhaline fish larvae ingest more microplastic particles in seawater than in freshwater

Microplastic (MP) pollution is a major concern in aquatic environments. Many studies have detected MPs in fishes; however, little is known about differences of microplastic uptake by fish in freshwater (FW) and those in seawater (SW), although physiological conditions of fish differ significantly in the two media. In this study, we exposed larvae (21 days post-hatching) of Oryzias javanicus (euryhaline SW) and Oryzias latipes (euryhaline FW), to 1-µm polystyrene microspheres in SW and FW for 1, 3, or 7 days, after which, microscopic observation was conducted. MPs were detected in the gastrointestinal tracts in both FW and SW groups, and MP numbers were higher in the SW group in both species. Vertical distribution of MPs in the water, and body sizes of both species exhibited no significant difference between SW and FW. Detection of water containing a fluorescent dye revealed that O. javanicus larvae swallowed more water in SW than in FW, as has also been reported for O. latipes. Therefore, MPs are thought to be ingested with water for osmoregulation. These results imply that SW fish ingest more MPs than FW fish when exposed to the same concentration of MPs.

Detection methods of micro and nanoplastics

Plastics and related contaminants (including microplastics; MPs and nanoplastics; NPs) have become a serious global safety issue due to their overuse in many products and applications and their inadequate management, leading to possible leakage into the environment and eventually to the food chain and humans. There is a growing literature reporting on the occurrence of plastics, (MPs and NPs) in both marine and terrestrial organisms, with many indications about the harmful impact of these contaminants on plants and animals, as well as potential human health risks. The presence of MPs and NPs in many foods and beverages including seafood (especially finfish, crustaceans, bivalves, and cephalopods), fruits, vegetables, milk, wine and beer, meat, and table salts, has become popular research areas in recent years. Detection, identification, and quantification of MPs and NPs have been widely investigated using a wide range of traditional methods, such as visual and optical methods, scanning electron microscopy, and gas chromatography-mass spectrometry, but these methods are burdened with a number of limitations. In contrast, spectroscopic techniques, especially Fourier-transform infrared spectroscopy and Raman spectroscopy, and other emerging techniques, such as hyperspectral imaging are increasingly being applied due to their potential to enable rapid, non-destructive, and high-throughput analysis. Despite huge research efforts, there is still an overarching need to develop reliable analytical techniques with low cost and high efficiency. Mitigation of plastic pollution requires establishing standard and harmonized methods, adopting holistic approaches, and raising awareness and engaging the public and policymakers. Therefore, this chapter focuses mainly on identification and quantification techniques of MPs and NPs in different food matrices (mostly seafood).

Impacts of nano/micro-plastics on safety and quality of aquatic food products

The spread of nano/microplastics (N/MPs) pollution has gained importance due to the associated health concerns. Marine environment including fishes, mussels, seaweed and crustaceans are largely exposed to these potential threats. N/MPs are associated with plastic, additives, contaminants and microbial growth, which are transmitted to higher trophic levels. Foods from aquatic origin are known to promote health and have gained immense importance. Recently, aquatic foods are traced to transmit the nano/microplastic and the persistent organic pollutant poising hazard to humans. However, microplastic ingestion, translocation and bioaccumulation of the contaminant have impacts on animal health. The level of pollution depends upon the pollution in the zone of growth for aquatic organisms. Consumption of contaminated aquatic food affects the health by transferring the microplastic and chemicals. This chapter describes the sources and occurrence of N/MPs in marine environment, detailed classification of N/MPs based on the properties influencing associated hazard. Additionally, occurrence of N/MPs and their impact on quality and safety in aquatic food products are discussed. Lastly, existing regulations and requirements of a robust framework of N/MPs are reviewed.

Are microplastics contributing to pollution-induced neurotoxicity? A pilot study with wild fish in a real scenario

Pollution-induced neurotoxicity is of high concern. This pilot study investigated the potential relationship between the presence of microplastics (MPs) in the brain of 180 wild fish (Dicentrarchus labrax, Platichthys flesus, Mugil cephalus) from a contaminated estuary and the activity of the acetylcholinesterase (AChE) enzyme. MPs were found in 9 samples (5% of the total), all of them from D. labrax collected in the summer, which represents 45% of the samples of this species collected in that season (20). Seventeen MPs were recovered from brain samples, with sizes ranging from 8 to 96 μm. Polyacrylamide, polyacrylic acid and one biopolymer (zein) were identified by Micro-Raman spectroscopy. Fish with MPs showed lower (p ≤ 0.05) AChE activity than those where MPs were not found. These findings point to the contribution of MPs to the neurotoxicity induced by long-term exposure to pollution, stressing the need of further studies on the topic to increase 'One Health' protection.

Dried fish more prone to microplastics contamination over fresh fish - Higher potential of trophic transfer to human body

Globally, microplastics (MPs) contamination in aquatic organisms is emerging as an alarming phenomenon. In the present study, we investigated MPs in three commercially important fishes (Bombay duck Harpadon nehereus, ribbon fish Trichiurus lepturus and hairfin anchovy Setipinna phasa) in fresh and dried conditions collected from two sites (Chattogram and Kuakata) of the Bay of Bengal. It was evident that fresh T. lepturus ingested highest amount of MPs through the gills (6.41 mps/g) from Chattogram followed by in the gastrointestinal tract, GIT (6.20 mps/g) and in the muscle (1.20 mps/g) from Kuakata. Among the fresh fishes, H. nehereus from Kuakata accumulated highest amount of MPs (0.21 mps/g), while S. phasa from Kuakata contained the least amount of MPs (0.06 mps/g). On the other hand, among the dried fishes, T. lepturus from Kuakata contained highest amount of MPs (46.00 mps/g), while S. phasa from Kuakata retained lowest amount of MPs (2.17 mps/g). Strangely, all the dried fishes showed significantly higher amount of MPs compared to fresh fishes from both the locations. Fiber was the most dominant type of shape of MPs which accounted 66 %, followed by fragment (27.38 %), microbeads (3.59 %), film (1.48 %), foam (1.31 %) and pellet (0.25 %). Size-wise, the major portion (39.66 %) of MPs was present to be in size range less than 0.5 mm followed by 37.67 % in the size range of 0.5-1.0 mm group and rest 22.67 % within 1.0-5.0 mm. Red (41.55 %) colored MPs was the most prominent, followed by brown (22.11 %), blue (16.32 %), pink (11.69 %), purple (5.10 %), and green (2.25 %). Among polymer types, low-density polyethylene (LDPE) was the most common (38 %), followed by polystyrene (PS-22 %), polyvinyl chloride (PVC-16 %), polyamide (PA-13 %) and ethylene-vinyl acetate (EVA-9 %). The present study confirms high occurrence of MPs in the dried fishes over the fresh fishes from the Bay of Bengal, with high potential of trophic transfer to the human body.

The contribution of estuaries to the abundance of microplastics in Jakarta Bay, Indonesia

Rivers are one of the main pollution routes to the ocean. This study examines the source of microplastics (MPs) in Jakarta Bay based on their characteristics and estimates MPs emissions from 9 estuaries around Jakarta Bay in 3 administrative areas (Tangerang, North Jakarta, and Bekasi). The sample used was the water's surface taken using a round net. The highest abundance was found in the Dadap River, and the lowest was in the Angke River. The characteristics of the MPs are dominated by fragments, the size of 300-500 μm, and composed of polyethylene. It shows that the MPs originate from the fragmentation of residents' plastic waste that has been in the waters for a quite long time. The nine estuaries also showed a high contribution to MPs in Jakarta Bay: from North Jakarta > Tangerang > Bekasi. The emission is highly correlated with water discharge and MPs' particles in each estuary.

Microplastics in ASEAN region countries: A review on current status and perspectives

A literature assessment was conducted to determine the current state of microplastics research in ASEAN countries focusing on 1) microplastics in water, sediment, and water organisms; 2) microplastics' sources and dispersion; and 3) microplastics' environmental consequences, including human toxicity. ASEAN countries contributed only about 5 % of the global scholarly papers on microplastics, with Indonesia contributing the most followed by Malaysia and Thailand. The lack of standard harmonized sampling and processing methodologies made comparisons between research difficult. ASEAN contributes the most to plastic trash ending up in the ocean, indicating a need for more work in this region to prevent plastic pollution. Microplastics are found in every environmental compartment; however, their distribution and environmental consequences have not been sufficiently investigated. There are very few studies on microplastics in the human blood system as well as respiratory organs like the lungs, indicating that more research is needed.

Spatio-temporal variation and seasonal dynamics of stranded beach anthropogenic debris on Indonesian beach from the results of nationwide monitoring

The first stranded macrodebris study on a national scale in Indonesia was conducted on 18 beaches from February 2018 to December 2019. The average weight and abundance of beach debris were higher between October and February (rainy season). The highest stranded macrodebris was located in Ambon, Manado, Takalar, and Padang. Plastic (46.38 %) was the most prevalent type of debris across all macrodebris categories, with single-use plastics such as plastic sachets, plastic bags, and plastic bottles being the dominant macroplastic debris (64.64 %). Based on CCI, HII, and BGI, 18 beaches are "moderately clean," with few hazardous items observed, and "Good." This anthropogenic macrodebris is thought to be more localized (55 %) than transboundary macrodebris. Litter control and environmental quality of this Indonesian coastal region should be improved through a proactive and flexible approach. Finally, extensive stranded beach debris monitoring is recommended to better understand the distribution of macrodebris in the region.

Effects of Human Activity on Markers of Oxidative Stress in the Intestine of Holothuria tubulosa, with Special Reference to the Presence of Microplastics

Pollution in the seas and oceans is a global problem, which highlights emerging pollutants and plastics, specifically microplastics (MPs), which are tiny (1 μm to 5 mm) ubiquitous plastic particles present in marine environments that can be ingested by a wide range of organisms. Holothurians are benthic organisms that feed on sediment; therefore, they can be exposed to contaminants present in the particles they ingest. The objective was to evaluate the effects of human activity on Holothuria tubulosa through the study of biomarkers. Specimens were collected in three different areas throughout the island of Eivissa, Spain: (1) a highly urbanized area, with tourist uses and a marina; (2) an urbanized area close to the mouth of a torrent; (3) an area devoid of human activity and considered clean. The results showed a higher presence of microplastics (MPs) in the sediments from the highly urbanized area in relation to the other two areas studied. Similarly, a higher number of MPs were observed in the digestive tract of H. tubulosa from the most affected area, decreasing with the degree of anthropic influence. Both in the sediment and in the holothurians, fibers predominated with more than 75% of the items. In the three areas, mesoplastics were analyzed by means of FTIR, showing that the main polymer was polypropylene (27%) followed by low-density polyethylene (17%) and polystyrene (16%). Regarding the biomarkers of oxidative stress, the intestine of H. tubulosa from the most impacted areas showed higher catalase, superoxide dismutase (SOD), glutathione reductase (GRd), and glutathione S-transferase (GST) activities and reduced glutathione (GSH) levels compared to the control area. The intermediate area only presented significant differences in GRd and GST with respect to the clean area. The activities of acetylcholinesterase and the levels and malondialdehyde presented similar values in all areas. In conclusion, human activity evaluated with the presence of MPs induced an antioxidant response in H. tubulosa, although without evidence of oxidative damage or neurotoxicity. H. tubulosa, due to its benthic animal characteristics and easy handling, can be a useful species for monitoring purposes.

Effect of landfill age on the physical and chemical characteristics of waste plastics/microplastics in a waste landfill sites

The landfills store a lot of waste plastics, thus it has been confirmed a main source for the occurrence of plastics/microplastic. Although there are some reports that microplastics (MPs) can generate in leachate and refuse samples from the landfill, it exist many blanks for the evolution of physical and chemical characteristics of waste plastics and microplastics with different landfill age. To explore the process that large pieces of plastic are fractured into microplastics, the waste plastics with landfill age from 7 to 30 years are surveyed from a typical landfill in Shanghai. The results show that PE and PP are the most common types of landfilling plastics, and their chemical composition also have changed due to the creation of CO and -OH. Moreover, the crystallinity is affected by plastic type and landfill age. The crystallinity of PP increased from 24.9% to 56.8%, but for PE, the crystallinity decreased from 55.6% to 20.8%. The mechanical properties of waste plastics were reduced significantly, which may be caused by changes in carbon-chain molecules. Al, Ti, Co, and other metal elements were detected on the plastic surface. The hydrophobic behavior of waste plastic is constantly decreasing (102.2°-80.1°) under long-term landfilling. By investigating the changes in the physical and chemical characteristics of waste plastics with different landfill age can shed light upon the process of environmental weathering of waste plastics. This provide theoretical guidance for reducing the transport of microplastics to the environment.

Seasonal heterogeneity and a link to precipitation in the release of microplastic during COVID-19 outbreak from the Greater Jakarta area to Jakarta Bay, Indonesia

To reduce microplastic contamination in the environment, we need to better understand its sources and transit, especially from land to sea. This study examines microplastic contamination in Jakarta's nine river outlets. Microplastics were found in all sampling intervals and areas, ranging from 4.29 to 23.49 particles m^-3. The trend of microplastic contamination tends to increase as the anthropogenic activity towards Jakarta Bay from the eastern side of the bay. Our study found a link between rainfall and the abundance of microplastic particles in all river outlets studied. This investigation found polyethylene, polystyrene, and polypropylene in large proportion due to their widespread use in normal daily life and industrial applications. Our research observed an increase in microplastic fibers made of polypropylene over time. We suspect a relationship between COVID-19 PPE waste and microplastic shift in our study area. More research is needed to establish how and where microplastics enter rivers.

A Meta-Analysis of the Characterisations of Plastic Ingested by Fish Globally

Plastic contamination in the environment is common but the characterisation of plastic ingested by fish in different environments is lacking. Hence, a meta-analysis was conducted to identify the prevalence of plastic ingested by fish globally. Based on a qualitative analysis of plastic size, it was determined that small microplastics (<1 mm) are predominantly ingested by fish globally. Furthermore, our meta-analysis revealed that plastic fibres (70.6%) and fragments (19.3%) were the most prevalent plastic components ingested by fish, while blue (24.2%) and black (18.0%) coloured plastic were the most abundant. Polyethylene (15.7%) and polyester (11.6%) were the most abundant polymers. Mixed-effect models were employed to identify the effects of the moderators (sampling environment, plastic size, digestive organs examined, and sampling continents) on the prevalence of plastic shape, colour, and polymer type. Among the moderators, only the sampling environment and continent contributed to a significant difference between subgroups in plastic shape and polymer type.

The occurrence and abundance of microplastics in surface water of the midstream and downstream of the Cisadane River, Indonesia

This study investigates microplastic contamination in the midstream to downstream of the Cisadane River and its confluence with the Java Sea. The abundance ranged between 13.33 and 113.33 particles m^-3 in surface water samples. Microplastic abundance in the downstream area was higher than midstream. We discovered 11 microplastic polymer types, with polyethylene, polystyrene, and polypropylene dominating (>70%) the chemical composition study result, which we hypothesized was owing to their ubiquitous use in daily household and industrial activities. Microplastic fragments with a diameter of 500-1000 m predominated in surface water samples. This study identifies possible microplastics pollution hotspots throughout the Cisadane rivers and selects sites that require additional sampling. Runoff from cities and landfills has the potential to have a significant impact on the accumulation and movement of microplastics from the inland to the Cisadane estuarine area. Additional research is necessary to determine how and where these microplastics particles enter rivers.

The impact of nano/micro-plastics toxicity on seafood quality and human health: facts and gaps

Contamination of the food and especially marine environment with nano/micro-plastic particles has raised serious concern in recent years. Environmental pollution and the resulting seafood contamination with microplastic (MP) pose a potential threat to consumers. The absorption rate of the MP by fish is generally considered low, although the bioavailability depends on the physical and chemical properties of the consumed MP. The available safety studies are inconclusive, although there is an indication that prolonged exposure to high levels of orally administered MP can be hazardous for consumers. This review details novel findings about the occurrence of MP, along with its physical and chemical properties, in the marine environment and seafood. The effect of processing on the content of MP in the final product is also reviewed. Additionally, recent findings regarding the impact of exposure of MP on human health are discussed. Finally, gaps in current knowledge are underlined, and the possibilities for future research are indicated in the review. There is an urgent need for further research on the absorption and bioavailability of consumed MP and in vivo studies on chronic exposure. Policymakers should also consider the implementation of novel legislation related to MP presence in food.

Microplastic ingestion by the sandfish Holothuria scabra in Lampung and Sumbawa, Indonesia

This study investigated the abundances and characteristics of microplastics in sediments and sandfish (Holothuria scabra) in Lampung and Sumbawa, Indonesia. Microplastics were found in 89.02% of all sandfish samples, with an average abundance of 2.01 ± 1.59 particles individual^-1. The abundance of microplastics was 58.42 ± 24.33 particles kg^-1 in surface sediments. Furthermore, there was a positive relationship between the abundance of microplastics in sandfish and sediments. Fragments and fibers with small-sized microplastics (300-1000 μm) were the most abundant types found in sandfish and sediments. Fourier-transform infrared (FTIR) analysis showed that polyethylene (30.08%), polypropylene (30.08%), polyurethane (12.20%), and polyethylene terephthalate (8.94%) were the most abundant polymers in the samples. Our results strongly indicate that microplastics in Lampung and Sumbawa originate from the fragmentation of large plastics. Better solid waste management in Indonesia is needed to reduce plastic waste leakage, which could become microplastics.

Spatiotemporal macro debris and microplastic variations linked to domestic waste and textile industry in the supercritical Citarum River, Indonesia

Rivers are the key conduits for land-to-sea debris transport. We present in situ monitoring data of macro debris and microplastic along the supercritical Citarum River in Indonesia We identified the dams as concentrated areas of microplastic. Plastics accounted for 85% of the riverine debris (5369 ± 2320 items or 0.92 ± 0.40 tons daily). We estimated macrodebris releases of 6043 ± 567 items or 1.01 ± 0.19 tons daily with a microplastic concentration of 3.35 ± 0.54 particles per m³ from Citarum River to sea. It has been suggested that population density and urbanization rate are major factors determining the spatiotemporal variability of macrodebris and microplastic abundances in the Citarum River. Our research highlights the importance of long-term monitoring to estimate debris and microplastics inflows along the Indonesian river to the world ocean as a benchmark for the reduction of macro and microdebris into the environment.

A Mini-Review of Strategies for Quantifying Anthropogenic Activities in Microplastic Studies in Aquatic Environments

Microplastic pollution is no longer neglected worldwide, as recent studies have unveiled its potential harm to ecosystems and, even worse, to human health. Numerous studies have documented the ubiquity of microplastics, reflecting the necessity of formulating corresponding policies to mitigate the accumulation of microplastics in natural environments. Although anthropogenic activities are generally acknowledged as the primary source of microplastics, a robust approach to identify sources of microplastics is needed to provide scientific suggestions for practical policymaking. This review elucidates recent microplastic studies on various approaches for quantifying or reflecting the degree to which anthropogenic activities contribute to microplastic pollution. Population density (i.e., often used to quantify anthropogenic activities) was not always significantly correlated with microplastic abundance. Furthermore, this review argues that considering potential sources near sample sites as characteristics that may serve to predict the spatial distribution of microplastics in aquatic environments is equivocal. In this vein, a watershed-scale measure that uses land-cover datasets to calculate different percentages of land use in the watershed margins delineated by using Geographic Information System (GIS) software is discussed and suggested. Progress in strategies for quantifying anthropogenic activities is important for guiding future microplastic research and developing effective management policies to prevent microplastic contamination in aquatic ecosystems.

Microplastic Contamination in Human Stools, Foods, and Drinking Water Associated with Indonesian Coastal Population

Approximately 381 million tons of plastic are produced globally every year, and the majority of it ends up as pollutants. In the environment, plastic waste is fragmented into microplastic particles less than 5 mm in size; owing to their small size, durability, and abundance, they can easily be dispersed, incorporated into the food chains, and enter the human body. The extent of microplastic exposure in the human body has become a major concern in many countries, including in Indonesia, the second largest plastic waste contributor in the world. Here, we report the detection of microplastics in human stools collected from a fisherman community in the coastal area of Surabaya, Indonesia. Microplastics were found in more than 50% of samples analyzed with a concentration ranging from 3.33 to 13.99 µg of microplastic per gram of feces (µg/g). HDPE was observed as the most prevalent type of microplastic, with an average concentration of 9.195 µg/g in positive samples. Different types of microplastics were also detected in seafood, staple foods, drinking water, table salts, and toothpaste, which were regularly used and consumed by the study participants. Results from this preliminary study indicate widespread contamination of microplastic in the human body and in consumables associated with the coastal populations of Indonesia.

Microplastic contamination of fish gills and the assessment of both quality assurance and quality control during laboratory analyses

Microplastic pollution has received substantial international attention in terrestrial and marine environments and in the atmosphere. In this study, we assessed microplastic pollution and analyzed the accumulation of microplastics in the gills of fish caught in the Zhoushan fishing ground from September 2017 to March 2018. The average abundance of microplastics was 0.49 ± 0.54 particles/gill and frequently found chemical polymers was polyethylene terephthalate. We also conducted experiments on microplastic pollution in the water and the working solutions used during the analytical process and found that the source of microplastic contamination was the solutions used. Moreover, we evaluated and scored experimental quality control and quality assurance adapted from the 'Total Accumulated Score' method. Valuable steps are recommended in order to produce reliable results and improve the quality of results in microplastic analyses.

Microplastic Contamination in the Human Gastrointestinal Tract and Daily Consumables Associated with an Indonesian Farming Community

Plastic is one of the most abundant pollutants in the environment. As a result of natural physical processes, large plastic waste is degraded into microsized particles (<5 mm) called microplastics. Because of their size, abundance, and durability, microplastics are widely distributed in the environment, contaminating food and water intended for human consumption. The extent of microplastic contamination in the human body is still unclear because there are few studies concerning microplastic contamination in human specimens and, in most studies, data were collected from city dwellers. Despite having the fourth largest population and being the fourth largest plastic waste producer in the world and second largest plastic polluter in the ocean, there are currently no data with respect to microplastic exposure for the Indonesian population. Several studies have reported on microplastic contamination in seafood and freshwater organisms from Indonesia, and it is likely that microplastics have contaminated the gastrointestinal tracts of Indonesians. Using Raman spectroscopy, we detected microplastic contamination in 7 out of 11 analyzed stool samples collected from a farming community in the highland village of Pacet, East Java, Indonesia. Polypropylene (PP) was the most abundant and prevalent type of microplastic observed, and it was found in four of the positive samples with an average concentration of 10.19 microgram per gram of feces (μg/g). Microplastics were also detected at high concentrations in tempeh (soybean cake, a staple protein source for Indonesians), table salts, and toothpaste, which were regularly consumed and used by the study participants. PP was particularly high in table salts (2.6 μg/g) and toothpaste (15.42 μg/g), suggesting that these products might contribute to the gastrointestinal contamination in the studied population. This pilot study indicated microplastic contamination in the rural Indonesian population and in their daily consumables, demonstrating the far-reaching extent of microplastic pollution beyond urban areas.

Do Freshwater Fish Eat Microplastics? A Review with A Focus on Effects on Fish Health and Predictive Traits of MPs Ingestion

Microplastics (MPs) have received increasing attention in the last decade and are now considered among the most concerning emerging pollutants in natural environments. Here, the current knowledge on microplastic ingestion by wild freshwater fish is reviewed with a focus on the identification of possible factors leading to the ingestion of MPs and the consequences on fish health. Within the literature, 257 species of freshwater fishes from 32 countries have been documented to ingest MPs. MPs ingestion was found to increase with rising level of urbanization, although a direct correlation with MPs concentration in the surrounding water has not been identified. MPs ingestion was detected in all the published articles, with MPs presence in more than 50% of the specimens analyzed in one study out of two. Together with the digestive tract, MPs were also found in the gills, and there is evidence that MPs can translocate to different tissues of the organism. Strong evidence, therefore, exists that MPs may represent a serious risk for ecosystems, and are a direct danger for human health. Moreover, toxicological effects have also been highlighted in wild catches, demonstrating the importance of this problem and suggesting the need for laboratory experiments more representative of the environmental situation.

Pathways of floating marine debris in Jakarta Bay, Indonesia

Jakarta is the capital of Indonesia with a high population density, which affects the amount of waste generated. The waste that ends up in Jakarta Bay has become an environmental problem. Understanding the pathway of marine debris in the ocean is important to identify the mitigation strategies. Before this study, the pathways and sources of marine debris in Jakarta Bay were unknown. By using virtual floating marine debris particles in a high-resolution ocean model, the fate of marine debris based on the pathways of particles released in Jakarta Bay in both forward and backward tracking experiments was analyzed. It was found that most of the particles from Jakarta Bay flow toward the Indian Ocean in all seasons. They flow off through the Sunda Strait and reach the open Indian Ocean after a few weeks. With regard to the source location, most particles that end up in Jakarta Bay come from the north of Java Island locally and from the Gulf of Thailand, Sumatra, and Kalimantan coasts. The particles do not appear to vary significantly across all seasons and identifying the pathway of marine debris might be useful in pollution reduction.

Unprecedented plastic-made personal protective equipment (PPE) debris in river outlets into Jakarta Bay during COVID-19 pandemic

Increased plastic uses during COVID-19 pandemic challenges efforts to reduce marine plastic debris. Despite recent observations of increased plastic-made personal protection equipment (PPE) waste in coastal areas, comparative data before and during the pandemic lacked. We present in situ monitoring data on riverine debris releases into Jakarta Bay, Indonesia, during COVID-19 pandemic relative to the 2016 baseline data. River debris at two river outlets - the Cilincing and Marunda Rivers, revealed a 5% increase in the abundance of debris and a 23-28% decrease in the weight of debris releases in March-April 2020 compared to March-April 2016, suggesting a compositional shift towards lighter debris. Plastics continued to dominate river debris at 46% (abundance) or 57% (weight). Unique to the pandemic, we observed an unprecedented presence of PPE (medical masks, gloves, hazard suits, face shields, raincoats) that accounted for 15-16% of the collected river debris of 780 ± 138 items (abundance) or 0.13 ± 0.02 tons (weight) daily. The observed increased plastic-made PPE in river outlets urges for improved medical waste management of domestic sources during the prolonged pandemic.

Micro- and mesoplastics release from the Indonesian municipal solid waste landfill leachate to the aquatic environment: Case study in Galuga Landfill Area, Indonesia

Small-sized plastic debris (micro- and mesoplastics) are emerging pollutants and widely detected in aquatic environments. However, micro- and mesoplastics pollution research with regard to landfills is limited. In this study, the occurrence, characteristics, and possible release of micro- and mesoplastic waste from the Galuga landfill leachate to the aquatic environment were studied. Micro- and mesoplastics were identified in all surface water samples from leachate influent and effluent of Galuga landfills. The average daily release to the aquatic environment was estimated at 80,640 ± 604.80 microplastic and 618,240 ± 1905.45 mesoplastic particles, respectively. The amount of microplastic increased three-fold and nine-fold for mesoplastics after input from the leachate drain. Micro- and mesoplastic main chemical compositions were polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyester, and cellophane. This study implied that the leachate may cause micro and mesoplastic contamination to the aquatic environment. The results raised the knowledge of small-sized plastic debris in aquatic environments.

Spatial and temporal distribution of microplastic in surface water of tropical estuary: Case study in Benoa Bay, Bali, Indonesia

In 2010, Indonesia estimated as the second-largest country in the world that donates plastic to the sea. This study aims to investigate the spatial and temporal distribution of microplastics in tropical estuaries. The sampling was carried out in Benoa Bay with four repetitions representing the wet and dry seasons. Spatially it was found that the highest microplastic abundance around the Suwung landfill, while the lowest at Badung River Estuary, middle, and an inlet of the Benoa Bay. The highest percentage to the lowest microplastic based on the size was 500-1000 μm (37.9%), >1000 μm (35.7%), 300-500 μm (22.1%), and <300 μm (4.3%), while based on the shape were fragments (73.19%), foam (17.02%), fiber (6.38%), and granule (3.40%). No significant differences were found between the wet and dry seasons based on the abundance, but significantly varied based on size and shape. Polymers of microplastics were dominated by polystyrene, polypropylene, and polyethylene.

Characterization of microplastics in mangrove sediment of Muara Angke Wildlife Reserve, Indonesia

An investigation of microplastic abundance and its characteristics was conducted in Muara Angke Wildlife Reserve, a relic mangrove forest in the Jakarta metropolitan, to contribute to marine microplastics' national data inventory. Microplastics were found in all the stations, with an average of 28.09 ± 10.28 particles per kg of dry sediment (n kg^-1). Sediments in the outside mangrove area contained more microplastics than the inside area. Foam form was the most dominant in all the samples and was found more abundant on the outside. More than half of microplastics were of size <1000 μm, and nearly 50% were polystyrenes. This polymer is widely used for food packaging, which is prone to be fragmented. Polypropylene and polyethylene form another 50% of microplastics, which are widely used for textiles and fishing gears. As Jakarta is the largest city in Indonesia, this microplastic dataset may be the benchmark for other mangroves around the country.