Color Of Microplastics Research Articles

Distribution characteristics of microplastics in typical organic solid wastes and their biologically treated products

Enormous production, use, and disposal of plastic goods present great challenges to environmental sustainability. Microplastics (MPs) are added into land which may serve as a larger MP repository than the ocean. Organic solid wastes and their biologically treated products can easily enter the soil and accumulate in soil systems. The current work deals with the extraction, identification, and distribution of MPs in typical organic solid wastes (food waste, livestock manure, and sludge) and their biologically treated products. The ecological risks of MPs were also preliminarily evaluated. The results showed that the abundance of MPs in organic solid wastes was in order of sludge > food waste > livestock manure. The main categories of MPs were fibers and films including PE, PP, and PET. The colors of MPs were mainly black, red, blue, and green. MPs generally exhibited bulges, depressions, cracks, or holes after biological treatment, and would be degraded into smaller fragments with potentially greater ecological risks. It was also found that the polymer risk index (H) of MPs in semi-dynamic composting products, compound fertilizer, and biogas residue of sedimentation tank sludge were higher than 10, reflecting their high ecological risk. Thus, it is recommended that the input of (micro)plastics to organic solid wastes streams should be minimized and related management should be established for the utilization of organic solid wastes and their biologically treated products.

Microplastic contamination of coastal hill soils: Perspective of Rohingya Refugee camps in Bangladesh

ABSTRACT Microplastics (MPs) pollution of environments due to human activities is a global concern. In the present study, we examined the occurrence of MPs in coastal hill soils (burned and non-burned) collected from the Rohingya Refugee camps in Cox’s Bazar, Bangladesh. The total number of MPs per kg of burned soil (402–403 items/kg) sample was significantly higher than that in non-burned soil (210 items/kg) sample. Fibers (24–57%) dominated in all the samples, followed by fragments (18–51%), sheet (12–29%), and microbeads (12–13%). The most common color of MPs was blue (16–68%), followed by red (14–25%), transparent (14–24%) and brown (14–22%). Among the size groups, MPs of 0.5-<1.0 mm (34–44%) dominated in all the samples, followed by 1.0–5.0 mm (27–45%) and <0.5 mm (14–29%). Attenuated Total Reflectance Fourier Transform Infrared spectroscopy analysis confirmed the most abundant polymer type in burned soil was polystyrene (28%) followed by polypropylene (23%), polyethylene (21%), polyamide (15%), ethylene-vinyl acetate (8%), and polyvinyl chloride (3%). The study confirms the presence of high MPs loads in burned soil, with high potential of trophic transfer to plants and washed out to aquatic environment and will appear as base line information for further assessment of MPs effects on biota.

Distribution Characteristics of Microplastics and Their Migration Patterns in Xiangxi River Basin

Microplastics as a prevalent pollutant in water bodies have recently attracted widespread attention. To investigate the spatial and temporal distribution characteristics of microplastics in freshwater rivers and their migration patterns, the surface water, sediments, and subsidence zone of the Xiangxi River, a tributary of the Yangtze River, were sampled and analyzed in November 2020 and April 2021, respectively. The results showed that the average abundance of microplastics in the surface water of Xiangxi River was (6.64±1.32) n·L-1 in flat water and (5.00±1.07) n·L-1 in dry water, the average abundance of microplastics in sediments was (0.56±0.13) n·g-1 in flat water and (0.41±0.09) n·g-1 in dry water, and the average abundance of microplastics in the subsidence zone was (0.53±0.15) n·g-1 in flat water and (0.68±0.18) n·g-1in dry water. There were significant differences in the abundance distribution of microplastics in the surface water, sediments, and subsidence zone (P<0.05). In the surface water and sediments, the particle size of microplastics was mainly distributed in the range of 0.1-0.5 mm, and in the subsidence zone, it mainly ranged from 1-5 mm. The color of microplastics was mainly transparent in the surface water and subsidence zone and blue in sediments. The morphology of microplastics in the Xiangxi River basin was mainly fiber, and the materials were mainly polyethylene (PE) and polypropylene (PP). There were many factors affecting the distribution of microplastics. The analysis results showed that the abundance of microplastics in the surface water was negatively correlated with the flow rate of the water body. The abundance of microplastics in the sediment was related to the substrate type of the riverbed and negatively correlated with the substrate particle size. Combined with the microplastic abundance data of each sampling site, it was found that there was a significant migration process of microplastics in the spatial distribution of the Xiangxi River in the watershed. Along the river longitudinal direction, the longitudinal migration of microplastics in the surface water was along the river direction, and in the vertical direction, it showed the mutual migration between the water body and the subsidence zone and the water body and sediments.

Identification Of Microplastics Content in Sediment, Water and Digestive Channel of Milkfish (Chanos chanos) in Sidoarjo Pond

Microplastics are a form of new pollution that the Indonesian people are not aware of. The factors for the entry of microplastics into pond waters are water sources, anthropogenic activities, and pond cleanliness. The purpose of this study was to determine the abundance of microplastics, the color and shape of microplastics, and the types of microplastic polymers found in sediment, water, and the digestive tract of milkfish (Chanos chanos) in Sidoarjo ponds. The average abundance of microplastics in sediment samples obtained from semi-intensive ponds is 300 particles per 50 grams, while the sediment samples from traditional ponds are 613 particles per 50 grams. The average abundance of microplastics in the semi-intensive pond water samples was 2.1 particles per 20 liters and in traditional ponds was 2.3 particles per 20 liters. The average abundance of microplastics in the milkfish (Chanos chanos) samples from the Semi-Intensive Pond was as many as 6 particles per tail, while the Traditional Pond had 9.5 particles per tail. In this study, four colors of microplastics were found, namely blue, black, red, and transparent, while the microplastics obtained were fiber, fragment, and filament. The types of microplastic polymers encountered in this study were dominated by polyamide or nylon polymers. In sediment samples from both ponds, we found the presence of Polyamide or Nylon polymers, namely Polystyrene and Polyamide or Nylon, and in the digestive tract of milkfish (Chanos chanos), namely Polyamide or Nylon.

Occurrence and sources of microplastics in dust of the Ebinur lake Basin, northwest China.

Currently, there is a lack of studies on microplastic pollution in mountain terrains and foothills areas in Northwest China and Central Asia. Here, we collected monthly dusts samples for one year and we studied the distribution, pollution levels, and sources of microplastics in atmospheric dust fall in the Ebinur Lake Basin in Northwest China. Results showed that the average content of dust microplastic on construction land was 28.61 ± 1.13mg/kg, followed by farmland (20.25 ± 1.56mg/kg), forest (19.52 ± 1.06mg/kg), and deserts (8.08 ± 0.56mg/kg). Regarding different land use types, atmospheric dust reduction dominated on farmland (58.64%), followed by urban area (26.65%), forest (9.76%), and desert (4.95%). Regarding the shape of microplastics, the order of occurrence in dust was film (46.85%) > fiber (35.15%) > foam(12.35%) > fragment (5.65%). In this study, four colors of microplastics were found in dust, and white accounted for the largest proportion (52.15%), followed by transparent (18.65%), black (19.45%), and green (9.75%). The main components of film microplastics in atmospheric dustfall in the Ebinur Lake Basin were PE and PP, and their sources were mainly plastic products in daily life, plastic industrial packaging materials from urban enterprises, broken plastic woven bags, and PET mostly from fabric fragment emissions. The abundance of microplastics in dust was correlated with atmospheric dust pH, EC, and total salt content. The contents of seven heavy metals (Cu, Ni, Cd, Pb, Cr, Mn, and Co) adsorbed by microplastics were also correlated with pH, EC, and total salt content. Our results represent a reference for microplastics pollution prevention in mountain terrains and foothills areas in northwest China and Central Asia.

Distribution and occurrence of microplastics in wastewater treatment plants

Microplastic pollution is an alarming problem into aquatic environment. Wastewater treatment plants (WWTPs) with applied technologies are strictly interested in the technical challenges with budget calculations and sustainable development without contaminants. WWTPs are suspected as potential sources discharging microplastics (MPs) into the environment. This study investigated the distribution and occurrence of MPs in influent and effluent of three typical industrial wastewater treatment plants (WWTPs) named HoaCam WWTP (HC WWTP), DaNang WWTP (DN WWTP), and HoaKhanh WWTP (HK WWTP) in Danang city, Vietnam. The results showed that the abundance of MPs total is 183–443 particles/L and 138–340 particles/L in the influent and the effluent. The average MPs removal efficiency obtained 25.5%, 21.8% and 25.3% at HC, DN and HK of three WWTPs, respectively. Hence, the average loading capacity of MPs discharged to recipient sources is 3.8 × 10 7 , 8.3 × 10 7 and 1.5 × 10 9 particles per day in the HC, DN, HK WWTPs, respectively. The majority of MPs identified in this study included a profile of size, shape type, color and chemical compositions of MPs. The sizes of MPs highly varied from 1.6 to 5000 μ m with the abundant MPs types of fiber and fragment in both the influent and the effluent. In addition, the colors of MPs such as yellow, white, blue and black are presented. Using Fourier Transform Infrared spectroscopy (FTIR), the main polymer compositions of MPs included polyethylene terephthalate (PET), polyethylene (PE), nylon and polyvinyl chloride (PVC) were determined in three WWTPs. • WWTPs were considered as potential sources discharging MPs into the aquatic environment. • The abundance of MPs in the influent is lightly higher than that in the effluent of three WWTPs. • The fibber and fragment shapes in both the influent and the effluent of WWTPs were dominant. • Main polymer compositions of microplastics were polyethylene terephthalate (PET), polyethylene (PE), nylon and polyvinyl chloride (PVC) in WWTPs.

Seasonal variation and ecological risk assessment of microplastics ingested by economic fishes in Lake Chaohu, China

Microplastic (MP) contaminations in freshwater organisms have attracted substantial attention worldwide. However, seasonal field studies of MPs concentrations in aquatic life are scarce. In this study, we analyzed the seasonal variation and ecological risk of MPs concentrations in economic fish species from Lake Chaohu in China between wet and dry seasons. Within both seasons, MPs in fish were systematically analyzed using methods of KOH digestion, NaCl density floatation and raman spectroscopy. MPs abundance in economic fishes were significantly higher in dry season than that in wet season, which can be ascribed to the MPs' amplification effects in lacustrine ecosystems during dry season. Whereas, our results recorded similar and homogenized characteristic composition of MPs in economic fishes between wet and dry seasons. In both seasons, fiber was the main morphological type, black and blue were the most common MPs color, and MPs ranging from <0.5 mm accounting for the most abundant size. In addition, polypropylene (PP) and polyethylene terephthalate (PET) accounted for the most abundant polymer type detected by economic fishes in both seasons. In terms of feeding groups and habitat preferences, planktivorous and pelagic fish species exhibited sensitive variations of MPs concentrations between wet and dry seasons, thus being highlighted as good bioindicators of MPs contaminants in freshwater ecosystems. Our results revealed higher ecological risks of MPs in wet season than that in dry season when indicating from polymer risk index (H). By providing detailed and direct toxicity information, our study highlights the usage of polymer risk index for ecological risk assessment in aquatic organisms.

Yellowing, Weathering and Degradation of Marine Pellets and Their Influence on the Adsorption of Chemical Pollutants.

Marine microplastics (MPs) are exposed to environmental factors, which produce aging, weathering, surface cracking, yellowing, fragmentation and degradation, thereby changing the structure and behavior of the plastic. This degradation also has an influence on the adsorption of persistent organic pollutants over the microplastic surface, leading to increased concentration with aging. The degradation state affects the microplastic color over time; this is called yellowing, which can be quantified using the Yellowness Index (YI). Weathering and surface cracking is also related with the microplastic yellowing, which can be identified by Fourier transform infrared spectroscopy (FTIR). In this study, the degradation state of marine microplastic polyethylene pellets with different aging stages is evaluated and quantified with YI determination and the analysis of FTIR spectrums. A color palette, which relates to the microplastic color and YI, was developed to obtain a visual percentage of this index. The relation with the adsorption rate of persistent organic pollutant over the microplastic surface was also determined.

Distribution and characterization of microplastics in marine sediments from the Montenegrin coast.

PurposePlastic pollution in the world has led to an abundance of microplastics (MPs) and has been identified as a potential factor that can lead to serious environmental problems, especially in oceans and seas. Information on the current status of MPs pollution along the Montenegrin coast is insufficiently investigated. This study monitors the abundance, distribution, and sources of MPs, and identifies present polymers in the surface sediment of the Montenegrin coast, as well as comparison with previous research.Materials and methodsTen sampling sites along the Montenegrin coast were selected to collect surface sediment samples. The upper layer of sediment (0–5 cm) was collected by a Petite ponar grab. The samples were dried, and density separation was performed using a NaCl solution. The abundance and morphological characteristics of MPs were determined using an optical microscope (DP-Soft software), while FT-IR analysis was done to identify the polymer type.Results and discussionMicroplastics were identified in all sediment samples with an average abundance of 307 ± 133 (SD) MPs/kg in dry sediment. The highest abundance of MPs was found in locations in the vicinity of highly populated areas, near wastewater discharges, and areas with high fishing and tourist activities. The most dominant shape types of MPs in all samples were filaments and fragments. The most common colors of MPs were blue and red, while the dominant MPs sizes were 0.1–0.5 mm and 0.5–1.0 mm. Of the eight identified polymers, PP, PE, and PET were the most common.ConclusionThis study reveals MPs characteristics (abundance, distribution, shape type, colors, size, polymers type) in surface sediment along the Montenegrin coast, as well as the most significant sources of MPs pollution, and provides important data for further research on MPs to identify the effects of MPs pollution on the quality, health, and functionality of the marine environment.

Distribution and characteristics of microplastics in surface water at some beaches in Thanh Hoa province, Viet Nam

Microplastics present in high density in coastal marine environments have been reported by many published works worldwide. Microplastic presence poses a major threat to all organisms that come into direct contact with them in the aquatic environment because they are non-biodegradable and adsorbable to some toxic substances. Besides, through the food chain, it can affect human health. This study provides data on the density and characteristics of microplastics such as shape, size, and color in the aquatic environment of three beaches (Hai Tien, Sam Son, Hai Hoa) in Thanh Hoa province. Microplastics were detected at all sampling locations at high abundance. The largest microplastic abundance was 44.1 items/m3 at Hai Tien beach, while the smallest was 15.5 items/m3 at Sam Son beach. The results indicated that the most common microplastic shape was fragment shape which accounted for 50.2 to 80.2% of total microplastics. The size was smaller than 500 µm covered from 66.1 to 87.7 % of total microplastics. Among that, white, yellow, and black are the main colors of microplastics in the aquatic environment of this region.

Microplastic Pollution in the Inlet and Outlet Networks of Rawa Jombor Reservoir: Accumulation in Aquatic Fauna, Interactions with Heavy Metals, and Health Risk Assessment

Streams are regarded as a pathway for spreading microplastics from land to various aquatic systems. The contamination of streams connected to the Rawa Jombor Reservoir may increase microplastic concentrations in the reservoir. The water coming out of the reservoir carries microplastics that spread out into the stream networks around the reservoir. Heavy metals have a high affinity for microplastics, increasing metal burdens on the surface of microplastics. The transfer of microplastics along the food chain leads to the possibility of increased adverse effects on organisms, mainly top predators. This research evaluated the accumulation and characterization of microplastics in water, sediment, and aquatic fauna (zooplankton, benthos, and fish); interactions with heavy metals (Pb, Cu, Cd, and Zn); and health risk assessment. Microplastics were collected from six sampling locations. The density, type of polymers, and color of microplastics were analyzed, as well as heavy metal concentrations on the surface of microplastics and a health risk assessment. The results showed microplastic contamination at a moderate level. The accumulation of microplastics in aquatic fauna showed the same pattern as microplastics in the environment. Microplastic concentrations in aquatic fauna showed an increase through trophic transfer and indications of biomagnification. Heavy metals were adsorbed on the surface of microplastics in high concentrations. Based on the health risk assessment, microplastic contamination of fish at the inlet and outlet of the Rawa Jombor Reservoir is still safe, but further monitoring is needed because of the possible long-term health hazards that may arise.

Black microplastic in plastic pollution: undetected and underestimated?

Plastic pollution includes microplastics. The environmental ubiquity of microplastics (&lt; 5 mm) is evident and the leak of microplastics into the environment is projected to increase globally. Microplastics in the environment possess high heterogeneity in polymer composition, particle size, shapes, and surface chemistry, which sometimes result in contradictory toxicological findings. However, much less attention is paid to the color of microplastics, particularly black plastics that are the least recycled and account for a significant proportion of total plastic waste and environmental microplastics. In the present perspective article, based on 50 field-based research articles on microplastics published from 2014 to 2022 and our own research experience, we raised specific environmental concerns about black microplastics and emphasized the challenges posed by black microplastics in multiple aspects. Future prospects were also discussed for better mitigating black microplastics in the context of plastic pollution.

Seasonal distribution of microplastics in the surface water and sediments of the Vellar estuary, Parangipettai, southeast coast of India

Microplastics (MPs) are toxic pollutants, which are found ubiquitously in the marine environment. The present study aimed to assess the level of MP contamination in Vellar estuary, southeast coast of India. MP abundance in surface water and sediments ranged from 1.15 ± 0.01 to 5.14 ± 0.04 items/m3 and 24.8 ± 0.75 to 43.4 ± 0.98 particles/kg d.w., respectively. Fiber, fragment, film, pellet and glitter were present in the study area. In total, ten colors of MPs were found in the study, of which black was the most abundant. Seven polymers in sediments and four polymers in water were characterized from the study area, among which LDPE was the most dominant. Sediment texture results showed that clay particles were able to retain a greater number of MPs. This study shows that the Vellar estuary is contaminated with MPs; however, further investigation is required to classify the estuary as polluted.

Investigating the Correlation of Microplastic Pollution Between Seawater and Marine Salt Using Micro-Raman Spectroscopy

Microplastics (MPs) are synthetic polymer pieces with a size of less than 5 mm that are ubiquitous in the marine environment. They have been recently detected in several wild species and sea products. An indispensable condiment in human food is marine salt that is produced from seawater. Since toxicity studies report potential health impacts when plastic debris is ingested, more attention must be paid to the MP contamination of sea salt and the underlying reasons for this. The central aim of this study is to evaluate the MPs contamination level of sea salt in correlation with the MPs contamination level of seawater in Vietnamese areas. Micro-Raman spectroscopy was employed to determine MPs in the samples collected from three artificial salt pans of Vietnam. The result revealed the presence of MPs in all study areas—Vung Tau (VT;14.54 MPs/L seawater and 114.67 MPs/kg salt), Ly Nhon (LN; 13.14 MPs/L seawater and 63.59 MPs/kg salt), and Can Thanh (9.42 MPs/L seawater and 93.69 MPs/kg salt). The comparisons highlight close correlations in the percentage, shape, size, and color of MPs, especially polyethylene, polyethylene terephthalate, and polypropylene particles extracted from the seawater and its salt. This study proved that seawater is a plastic pollution source for salts produced by traditional seawater evaporation. The study also alerts the prevalence of MPs in the environment and human consumables, thereby indicating that actions must be taken to reduce the pollution of water sources in Vung Tau and at the UNESCO Can Gio Mangrove Biosphere Reserve and improve salt production and refinery processes in order to minimize the number of MPs in final salt products for safe consumption.

Type and Distribution of Microplastics in Beach Sediment along the Coast of the Eastern Gulf of Thailand

In the oceans and coasts, plastic waste poses a global threat to biodiversity. This study examined the types and distribution of microplastics in beach sediment along the coast of the eastern Gulf of Thailand in March 2018 (northeast monsoon = dry season) and July 2018 (southwest monsoon = rainy season). Microplastic samples were collected from six stations including Koh Khramyai Beach (Chonburi Province), Koh Mannai Beach (Rayong Province), Chao Lao Beach (Chanthaburi Province, 3 stations), and Ploy Dang Beach (Trat Province). The results showed that the highest average abundances of microplastics in March and July were at Koh Mannai Beach (1698 pieces/m2) and Koh Khramyai Beach (799 pieces/m2), respectively. However, no microplastics were found at Ploy Dang Beach in July. According to polymer-type identification using an FTIR spectrometer, 17 polymer types were found in this study. Polyethylene terephthalate (PET = 39.6%) and polyamide (PA = 22.8%) were the polymer types found in the highest proportions in March and July, respectively. In addition, the fiber shape and transparent color of microplastics were found to be the most abundant.

Microplastic pollution in coastal ecosystem off Mumbai coast, India

Microplastics (MPs) are anthropogenic pollutants which can adsorb toxic substances from surrounding water and absorb into the fish body. During the present study, MPs were observed in water, sediment, and gastrointestinal tracts of marine biota samples collected from the coastal waters of Mumbai, India. The mean abundances of MPs recorded in water samples 372 ± 143 items/liter and 9630 ± 2947 items/kg dry weight (DW) in sediment samples. The mean abundance of MPs in pelagic fish species varied from 6.74 ± 2.74 to 9.12 ± 3.57 items/individual and in the demersal species the values ranged from 5.62 ± 2.27 to 6.6 ± 2.98 items/individual. Shape-wise, four type of MPs were observed in the surface waters, sediments and all studied species, predominantly fibers, followed by fragments, pellets/beads, and films. Seven different colors of MPs (red, blue, black, translucent, brown, green, and yellow) were observed from studied samples. MPs of size below 250 μm formed the dominant size in the surface water, sediments, and biota samples except Bombay duck and Malabar sole fish. Based on Raman spectroscopy analysis, eleven types of plastic polymers identified from all studied samples. Thus, presence of MPs in studied biota indicates the transfer of MPs through interlinked food chain/web to higher trophic levels and the occurrence of MPs in the fish gut underlines the necessity of more studies on processing interventions for reducing the microplastic contamination in fish for human consumption.

The concentration of microplastics in epibiont of green mussel (Perna viridis) from Maccini Baji waters, Pangkajene Kepulauan

The discharge of microplastics into marine waters harms aquatic ecosystems, especially for filter feeder organisms such as green mussels. The purpose of this study was to analyze the shape, size, and color of microplastics and the concentration of microplastics in the epibiont associated with green mussels (Perna viridis) and the effect of the presence of epibionts on the concentration of microplastics in green mussels as a substrate. Sampling was done using the purposive random sampling method. Determination of the number of samples using Lemeshow’s formula and obtained 99 green mussels associated with epibiont. The samples were divided into three groups, namely mussel associated with epibiont with microplastic found in epibiont, mussel associated with epibiont with microplastic found in mussel, and mussel without epibiont with microplastics in mussel. The results showed that the number of microplastics contaminated to the mussel group associated with epibiont with microplastic in the epibiont was 46 samples, to the mussel group associated with epibiont with microplastic in mussel was seven samples, and the mussel group without epibiont with microplastic in mussel there were 11 samples. The results also showed that if the microplastic were present in the epibiont, the green mussels associated with the epibionts did not contain microplastics. Conversely, if microplastics contaminated the green mussels, then epibionts were not contaminated by microplastics. The microplastics found ranged from 0.1-4.9 mm in length. The microplastic forms found were fibers and fragments. The microplastic colors found were red, blue, white, and black. The mean values of microplastic concentrations in epibiont, mussel associated with epibiont, and mussel without epibiont were 3.629 items/g, 0.7160 items/g, and 1.032 items/g, respectively.

Occurrence of Microplastics in the Gastrointestinal Tract and Gills of Fish from Guangdong, South China

Microplastic pollution has become a major global concern. Coastal areas are densely populated with human activity, commercial enterprises, and fishing, resulting in high incidences of fish microplastic pollution. It has been shown that microplastics exist in commercial fish in coastal areas of Guangdong, China. Most of the microplastics were less than 1 mm, white and blue fibers. The abundance, type, shape and color of microplastics in gills and in the gastrointestinal tract (GIT) of eight species of commercial fish in the coastal waters of central and western Guangdong Province were analyzed. The overall abundance of microplastic particles in fish was 6.6 items/individual, with an average of 2.2 particles in gills and 4.4 in the GIT. The GIT of carnivorous fish was less likely to ingest microplastics than that of herbivores or omnivores. Middle-water fish, on the other hand, are less likely to have their gills contaminated with microplastics. These results revealed the degree of microplastic pollution in fish tissues from the central and western coastal areas of Guangdong province. The quantity of microplastics in the GIT of fish in the Pearl River Delta was the highest compared with the surrounding areas.

Microplastic contamination assessment in water and economic fishes in different trophic guilds from an urban water supply reservoir after flooding

Rain and floods events are responsible for the transport of microplastics in freshwater ecosystems, yet to date, rare study has examined microplastics pollution in urban water supply reservoirs during such events. In this study, we investigated the concentrations and characteristics of microplastic in water and economic fish species with different feeding guilds in the Dafangying Reservoir, an important source of drinking water for Hefei city. Microplastic concentrations in water were relatively higher than that in natural lakes, indicating abundant microplastic contaminants input through overland runoff triggered by flooding. Our results detected five types (fiber, debris, film, microbead and particle) and six colors (black, transparent, blue, yellow, red and green) of microplastics in water samples. Fiber accounted for the dominant shape, which may result from the household sewage from washing clothes and desquamated fiber transported by wind and overland runoff. Meanwhile, transparent was the predominant microplastic color, which can be ascribe to the widely use of intentionally manufactured transparent disposable plastic commodities in cities. Then in fish samples, the microplastic concentrations ranged from 8.75 to 51.3 items/individual in fish guts, and 9.5–52.6 items/individual in fish gills. Our results demonstrated significant higher microplastic concentrations in planktivorous and herbivorous species. The filter feeding capture mode, i.e., engulfing floating prey through frequently drawing in large volume of water confused with microplastics, may result in the higher microplastic concentrations of planktivorous fishes. Due to the dense microplastics adhering on plant surface, herbivorous fishes can concentrate higher microplastics abundance through the ingestion of macrophytes. According to the biological concentration factor (BCF), all the determined microplastics gave BCF far below 1, suggesting the low bioaccumulation capacity of microplastics in fish species.

Preliminary results on microplastics in surface water from the downstream of the Day River

Microplastics (MPs), referring to plastic items ranging from 1 to 5000 µm long, are polluting the terrestrial and aquatic environments and are becoming a threat to the health of ecosystems, biota, and humans. Rivers are major carriers of these materials from the terrestrial environment to the oceans. In the present study, the occurrence of MPs in a peri-urban river was investigated. The Day river system is a good example of a peri-urban river strongly influenced by human activities in the whole basin. Water samples were collected from the downstream of the Day river, including Cau Que, Cau Do, and Do Thong, in the rainy and dry seasons using a plankton sampling net for identifying microplastic concentration, size, shape, color, and polymer composition. Microplastic abundance in the surface water ranged from 269,693±60,624 to 863,005±131,925 items/m3. The microplastic concentration in the rainy season was higher than that in the dry season. MPs abundance was increased at a site near urban areas with high human activity. The microplastic shape was collected in different seasons did not change significantly, with microplastic fibers as the major items, accounting for above 92% of the total items. Many fibers microplastics collected in this study were in small sizes of 300-1000 µm and 1000-2000 µm, occupying 78.5-85.7% of the total microplastic items. Purple was the most common color of microplastics. Polyethylene (PE) and polypropylene (PP) were major polymer types of the selected items in the surface water samples downstream of the Day River.