Microplastic contamination in Indian edible mussels (Perna perna and Perna viridis) and their environs

Microplastic contamination in marine mussels from the Atlantic coast of North Portugal and human risk of microplastic intake through mussel consumption

Microplastic (MP) pollution has become a global concern due to its potential impacts on the environment, ecosystem services and human health. The goals of the present study were to document the MP contamination in wild specimens of Mytilus galloprovincialis sampled along the Atlantic coast of the North region of Portugal continental (NW Portuguese coast), and to estimate the human risk of MP intake (HRI) through the consumption of local mussels as seafood. Mussels were collected at four sampling sites along the NW Portuguese coast (40 mussels per site), and the whole soft body of each mussel was analysed for MP content. HRI estimates were based on the mean of MP items per wet weight of mussel analysed tissue (MP/g) and consumption habits. A total of 132 MP items were recovered from mussels. MP had diverse sizes (98-2690 μm) and colours. The most common shapes were fibres (39%) and pellets (36%). Five polymers were identified in the MP: polyethylene (50%), polystyrene (15%), poly(ethylene vinyl acetate) (14%), polyamide (12%) and polypropylene (9%). From the 160 analysed mussels, 55% had MP. The mean and standard error of the mean of mussel contamination ranged from 0.206 ± 0.067 and 0.709 ± 0.095 MP/g. Compared to estimates based on MP contamination in mussels from other areas and varied consumption habits, the HRI through the consumption of mussels from the NW Portuguese coast is relatively low.

Proposed validation stages for MPs extraction from edible mussels (Mytilus galloprovincialis)

The potential presence of microplastics (MPs) in seafood products presents significant health concerns, demanding the adoption of standardized and validated methodologies. In this study, we introduce a validated method and an innovative technique for extracting MPs from mussels using an oxidizing agent, Corolase enzyme, and a surfactant, thus eliminating the need for mechanical agitation. Evaluation of the extraction process focused on three critical parameters: recovery percentage, repeatability, and chemical integrity, along with color stability. To ensure precision and reliability, low-density infrared spectroscopy (LDIR) was employed to analyze the effect of spectrum quality (Q). Ultimately, this methodology was applied to identify MPs in commercial mussels, with results showcasing the viability of the proposed validation stages for MPs extraction, maintaining MPs integrity with high recovery percentages.

Microplastics pollution in the Surma River, Bangladesh: A rising hazard to upstream water quality and aquatic life

The ecological health of freshwater rivers is deteriorating globally due to careless human activities, for instance, the emission of plastic garbage into the river. The current research was the first assessment of microplastics (MPs) pollution in water, sediment, and representative organisms (fish, crustacean, and bivalve) from the Surma River. Water, sediment, and organisms were sampled from six river sites (Site 1: Charkhai; Site 2: Golapganj; Site 3: Alampur; Site 4: Kazir Bazar; Site 5: Kanishail and Site 6: Lamakazi), and major water quality parameters were recorded during sampling. Thereafter, MPs in water, sediment, and organism samples were extracted, and then microscopically examined to categorize selected MPs types. The abundance of MPs, as well as size, and color distribution, were estimated. Polymer types were analyzed by ATR-FTIR, the color loss of MPs was recorded, the Pollution Load Index (PLI) was calculated, and the relationship between MPs and water quality parameters was analyzed. Sites 4 and 5 had comparatively poorer water quality than other sites. Microplastic fibers, fragments, and microbeads were consistently observed in water, sediment, and organisms. A substantial range of MPs in water, sediment, and organisms (37.33-686.67 items/L, 0.89-15.12 items/g, and 0.66-48.93 items/g, respectively) was recorded. There was a diverse color range, and MPs of <200 μm were prevalent in sampling areas. Six polymer types were identified by ATR-FTIR, namely Polyethylene (PE), Polyamide (PA), Polypropylene (PP), Cellulose acetate (CA), Polyethylene terephthalate (PET), and Polystyrene (PS), where PE (41%) was recognized as highly abundant. The highest PLI was documented in Site 4 followed by Site 5 both in water and sediment. Likewise, Sites 4 and 5 were substantially different from other study areas according to PCA. Overall, the pervasiveness of MPs was evident in the Surma River, which requires further attention and prompt actions.

Microplastic contamination in filter-feeding oyster Saccostrea cuccullata: Novel insights in a marine ecosystem

Microplastic (MP) pollution has become a pressing global concern. Oysters are well-known filter feeders who ingest food by filtering microscopic particles suspended in the surrounding water. Along with organic matter, filter-feeding also causes accidental ingestion of MP by oysters. Hence, the aim of the current investigation is to understand the MP contamination in filter-feeding oysters. A total of 500 specimens of oyster Saccostrea cuccullata collected from the intertidal zone of five sampling locations on the Gujarat coast, India. Specimens underwent analysis following established protocols. Each specimen was found to exhibit MP contamination, showing an abundance of 2.72 ± 1.98 MPs/g. A negative relationship was found between shell length and MP abundance. Predominantly, fibers were documented across all study sites. Black, blue, and red-colored MPs with 1-2 mm sizes were most dominant. MP polymer composition was identified as polyethylene terephthalate and polypropylene. Findings provide baseline information on levels of MPs contamination, which can be used to monitor future effects of MP pollution.

A systematic review on microplastic contamination in marine Crustacea and Mollusca of Asia: Current scenario, concentration, characterization, polymeric risk assessment, and future Prospectives

Microplastics (MPs) pollution has wreaked havoc on biodiversity and food safety globally. The false ingestion of MPs causes harmful effects on organisms, resulting in a decline in biodiversity. The present review comprehended the current knowledge of MP contamination in Crustacea and Mollusca from 75 peer-reviewed articles published in Asia between 2015 and 2023. A total of 79 species (27 Crustacea and 52 Mollusca) have been recorded to be contaminated with MPs. Out of the total 27 species of Crustacea, Metopograpsus quadridentatus (327.56 MPs/individual) and Balanus albicostatus (0.42 MPs/individual) showed the highest and lowest contamination, respectively. Out of the total 52 species of Mollusca, Dolabella auricularia (2325 MPs/individual) and Crassostrea gigas and Mytilus edulis (0.2 MPs/individual) showed the highest and lowest contamination, respectively. In terms of country-wise MP contamination, China has the highest number of contaminated species in both phylums among Asia. Findings of pollution indices revealed a very high risk of MP contamination in all the countries. Fiber was reported predominantly in both groups. Blue and black-colored MPs having <500 μm and <500 μm-1 mm size were found dominantly in Crustacea and Mollusca, respectively. Polypropylene was recorded as the dominant plastic polymer in both Crustacea and Mollusca. In essence, this review has provided a comprehensive insight into MP concentration in Crustacea and Mollusca of Asia, highlighting variations among species and geographic locations. This understanding is crucial for tackling urgent environmental challenges, safeguarding human health, and promoting global sustainability initiatives amid the escalating issue of plastic pollution. PRACTITIONER POINTS: Microplastic pollution has created havoc on biodiversity and food safety. A total of 27 and 52 species of crustaceans and Mollusca have been recorded to be contaminated with MPs. Metopograpsus quadridentate and Dolabella auricularia have shown higher MPs contamination. Polypropylene was recorded as the dominant plastic polymer in both crustacean and Mollusca. Findings of pollution indices revealed a very high risk of MP contamination in all the countries.

Microplastics in retail shellfish from a seafood market in eastern Thailand: Occurrence and risks to human food safety

This study aimed to investigate the presence of microplastics in three economically essential shellfish species: green mussels, cockles and spotted babylon. The average abundance of microplastics ranged from 2.41 to 2.84 particles/g wet weight. The predominant shape was fiber, with colors ranging from black-grey to transparent. The size of the microplastics discovered was <1.0 mm. Polystyrene and polyethylene were the most detected types in mussels and cockles, while linen was the predominant type in spotted babylon. The Thai population's estimated annual intake (EAI) of microplastics through shellfish consumption ranged from 20.23 to 1178.42 particles/person/year. The potential human health risks were evaluated using the polymer hazard index (PHI), which led to risk categories III-IV. These findings, along with others from the literature, indicate that shellfish consumption may pose risks to human health, depending on the species consumed and the origin of the specimens.

Mussels (Mytilus spp.) in Svalbard contain microplastic particles in tissues: Implications for monitoring

We examined the presence of microplastics in blue mussels Mytilus spp. from the intertidal zone of western Spitsbergen in Arctic Svalbard. The optical microscopy technique detected a total of 148 microplastics, with the highest concentration per mussel being 24 particles. Microplastics were found in 84% of the examined mussels. The microplastics ranged in size from <0.5 mm to 5 mm and consisted of fibers (83%), fragments (13%), plates (3%), and spherules (1%). The micro-Raman spectroscopy technique revealed four different types of polymers: polyethylene (67%), nylon-12 (17%), low-density polyethylene (11%), and polypropylene (5%). Our research shows that Arctic coastal waters are polluted with microplastics notwithstanding their remoteness. These findings suggest that microplastic contamination may harm marine life and coastal ecosystems and require further research into long-term environmental effects. We also indicate that intertidal mussels may be beneficial for monitoring microplastics because they can be collected without involving diving.

To what extent is blue mussels caging representative of microplastics in the natural environment?

Bivalves have gained prominence in active biomonitoring of microplastics (MPs) pollution. Nevertheless, critical questions persist regarding blue mussels' selectivity and representativeness of the presence of microplastics in the natural environments. In this current study, we explored short- and long-term exposure durations for caged mussels, aiming to establish the minimum period required for them to attain a steady-state in microplastics retention and investigate their selectivity in a real-world context. Various deployment periods (1, 2, and 5 weeks) were tested, with concurrent collection of MPs from the surrounding water each week. The results revealed a significant increase in ingested MPs, reaching a threshold of approximately 1.4 MPs per gram of wet weight during the fifth week of caging. The characteristics of MPs found in mussels exhibited some differences from those collected in the surrounding waters and were less temporally variable. Notably, the collected caged mussels demonstrated a tendency to retain smaller particles (<80 μm). This study underscores complex processes governing MPs selection in natural environments and the need for further research to gain a more comprehensive understanding of the conditions and suitability of mussels as bioindicators for assessing MPs pollution.

Mitigating microplastic pollution: A critical review on the effects, remediation, and utilization strategies of microplastics

Microplastics are found ubiquitous in the natural environment and are an increasing source of worry for global health. Rapid industrialization and inappropriate plastic waste management in our daily lives have resulted in an increase in the amount of microplastics in the ecosystem. Microplastics that are <150 μm in size could be easily ingested by living beings and cause considerable toxicity. Microplastics can aggregate in living organisms and cause acute, chronic, carcinogenic, developmental, and genotoxic damage. As a result, a sustainable approach to reducing, reusing, and recycling plastic waste is required to manage microplastic pollution in the environment. However, there is still a significant lack of effective methods for managing these pollutants. As a result, the purpose of this review is to convey information on microplastic toxicity and management practices that may aid in the reduction of microplastic pollution. This review further insights on how plastic trash could be converted as value-added products, reducing the load of accumulating plastic wastes in the environment, and leading to a beneficial endeavor for humanity.

The spatial distribution and physico-chemical characteristic of microplastics in the sediment and cockle (Anadara granosa) from the coastal waters of East Java, Indonesia, and the health hazards associated with cockle consumption

This study evaluated microplastic (MP) abundances and physico-chemical characteristics in sediments and Anadara granosa along the East Java coast and their health implications. Fibers (74 %) dominated sediment MPs at south coast, while fragments (49-61 %) dominated north coast. Fiber (43-52 %) is the predominant MP in cockle tissues in all locations. Most MP in sediments (31-47 %) and cockle tissues (41-49 %) is black. The majority of microplastics (100-1500 μm) are found in sediment (73-90 %), and cockles (77-79 %). Very weak correlations found between the amount of MP and the length of the cockle shell. However, Spearman correlation shows that as the amount of MP in sediment increases, so does the amount of MP in cockle tissue. Each year, individuals of varying ages consume an average of 20,800 to 156,000 MP items. Cockles contain plasticizer components and microplastic polymers which are classified from II to V regarding of hazard levels, with V being the most hazardous.

Seasonal variation in the abundance of microplastics in three commercial bivalves from Bandon Bay, Gulf of Thailand

This study investigated the abundance of microplastics in three commercial bivalves found at Bandon Bay. Spatial-temporal differences in the concentration of microplastics were evaluated during the dry and wet seasons. The results showed that the highest abundance of microplastics in oysters, blood cockles, and green mussels was observed in fishery and aquaculture areas during the dry season, with 1.42 particles/g (w/w), 1.01 particles/g (w/w) and 0.87 particles/g (w/w), respectively. Microplastics were more abundant during the dry season compared to the wet season (p < 0.05), with fibre being the predominant shape and black being the major colour of particles. Cellophane was the most common type of polymer in all bivalves. This result is an important reference for understanding the status of microplastics in three commercial bivalves during different seasons and in different human activities, which should aid in understanding the sources of microplastics in Bandon Bay.

Microplastic accumulation in bivalves collected from different coastal areas of Vietnam and an assessment of potential risks

Microplastic (MP) pollution is an emerging problem in many areas around the world and in coastal areas of Vietnam, requiring more studies dedicated to the accumulation of this pollutant in the food chain as well as its potential risk to human health. This study investigated MP levels in tissues of five common bivalve species collected from aquaculture areas along the coast of Vietnam. MPs were found in all bivalve samples, with average values of 10.84 ± 2.61 items/individual or 2.40 ± 1.34 items/g wet weight. Impacts of feeding habits of bivalves showed influences on MP abundance in the samples. Fibers were the dominant shape of MPs recorded, most of which accumulated in the gills and digestive glands of all bivalve samples, with the majority falling within the size range of 300-2000 µm. MPs found in all studied species had relatively similar chemical compositions, mainly composed of polypropylene (PP) and polyethylene (PE). In this study, a diverse diet consisting of different bivalve species and detailed data on the consumption rate of these species were used to assess the human health risk of MPs dedicated to the coastal communities of Vietnam. The results suggested a significant part of MP uptake by human could be via bivalve consumption, in which removing viscera and proper depuration should be applied prior to eating, thereby reducing the risk.

The effect of interspecific and intraspecific diversity on microplastic ingestion in two co-occurring mussel species in South Africa

Interspecific and intraspecific diversity are essential components of biodiversity with far-reaching implications for ecosystem function and service provision. Importantly, genotypic and phenotypic variation within a species can affect responses to anthropogenic pressures more than interspecific diversity. We investigated the effects of interspecific and intraspecific diversity on microplastic ingestion by two coexisting mussel species in South Africa, Mytilus galloprovincialis and Perna perna, the latter occurring as two genetic lineages. We found significantly higher microplastic abundance in M. galloprovincialis (0.54 ± 0.56 MP items g-1WW) than P. perna (0.16 ± 0.21 MP items g-1WW), but no difference between P. perna lineages. Microbeads were the predominant microplastic (76 % in P. perna, 99 % in M. galloprovincialis) and polyethylene the prevalent polymer. Interspecific differences in microplastic abundance varied across locations, suggesting diverse sources of contamination. We suggest that microplastic ingestion can be species-specific even in organisms that coexist and play similar functional roles within ecosystems.

A critical review of microplastics toxicity and potential adverse outcome pathway in human gastrointestinal tract following oral exposure

Microplastics (MPs) are typically produced via environmental degradation of larger plastics, where they enter the human food chain. MPs are complex materials containing chemical and physical characteristics that can potentially affect their hazard and exposure. These physical properties can be altered by environmental exposure potentially altering any risk assessment conducted on the primary material. We conducted a literature review using an Adverse Outcome Pathway (AOP)-based approach from Molecular Initiating Event (MIE) to cell effect event to identify multiple knowledge gaps that affect MPs hazard assessment. There is some convergence of key biological events but could relate to most lying along well-established biological effector pathways such as apoptosis which can respond to many MIEs. In contrast, MIEs of chemicals will be via protein interaction. As MPs may occur in the lumen of the alimentary canal for example to the mucus, therefore, not requiring translocation of MPs across the epithelial membrane. At the other end of the AOP, currently it is not possible to identify a single adverse outcome at the organ level. This work did establish a clear need to understand both external and internal exposure (resulting from translocation) and develop hazard data at both levels to inform on risk assessments.

Quantitative assessment of microplastic contamination in muddy shores of Gulf of Khambhat, India

Microplastics (MPs) have become a global concern due to their widespread distribution in marine ecosystems. The present study was aimed to assess MPs contamination in 21 muddy shores sites situated in the Gulf of Khambhat. From each site, five samples (1 kg each) were collected. In the laboratory, the replicates were homogenated, out of which a 100 g sample was used for analysis. The total number of MPs, shape, colour, size and polymer composition of MPs were assessed. The MPs abundance ranged from 0.32 ± 0.18 particles/g (Jampore) to 2.81 ± 0.50 particles/g (Uncha Kotda) among different study sites. Moreover, threads were recorded maximum followed by films, foams and fragments. In case of MPs colour, black and blue coloured MPs occurred dominantly, with sizes ranging from 1 mm to 5 mm. FTIR analysis identified seven different types of plastic polymers, out of which polypropylene was the dominant plastic polymer (32.46 %) followed by polyurethane (32.16 %), acrylonitrile butadiene styrene (14.93 %), polystyrene (9.62 %), polyethylene terephthalate (4.61 %), polyethylene (3.71 %) and polyvinyl chloride (2.51 %). Based on the results of the Contamination factor (CF) value, Alang, Mahua, Ghogha and Uncha Kotda were identified as very high contaminated sites (CF ≥ 6). Pollution Load Index (PLI) value of entire study area revealed the Gulf of Khambhat as a polluted area with MPs contamination (PLI > 1). While value of Hazardous Index (H) identified 12 study sites as class-V risk category (H value > 10,000). Moreover, Pollution Risk Index (PRI) value revealed fifteen sites as very high contaminated sites (PRI > 1200). Pollution indices can be useful in predicting the level of MPs contamination at the study site. Overall, the present study provides the information on MPs contamination in the coastal region of the Gulf of Khambhat that can be used as a baseline data for future studies on the ecotoxicity of MPs on marine biota.

Oysters and mussels as equivalent sentinels of microplastics and natural particles in coastal environments

Filter-feeder organisms such as oyster and mussels are exposed to particles like microplastics (MPs). Although widely used to monitor MPs contamination, little is known about their performance as sentinels, which are biological monitors accumulating contaminants without significant adverse effects. This study comparatively evaluated the quantitative and qualitative accumulation of MPs by oysters (Crassostrea brasiliana) and mussels (Perna perna) along a gradient of contamination in a highly urbanized estuarine system of Brazil. In the most contaminated site, both species presented the worst status of nutrition and health, and also one of the highest MPs levels reported for molluscs to date (up to 44.1 particles·g^-1). Despite some inter-specific differences, oysters and mussels were suitable and showed an equivalent performance as sentinels, reflecting the gradient condition demonstrated for other contaminants in the region. The similarity in MPs accumulation was also observed for qualitative aspects (polymer composition, sizes, shapes and colors). Particles were mostly <1000 μm, fibrous, colorless and composed by cellulose and polymethyl methacrylate (PMMA). Thus, despite small variations, the usage of C. brasiliana and P. perna is recommended and provides reliable information for environmental levels of microplastics.

Binational survey using Mytilus galloprovincialis as a bioindicator of microplastic pollution: Insights into chemical analysis and potential risk on humans

Microplastic (MP) contamination in edible mussels has raised concerns due to their potential risk to human health. Aiming to provide valuable insights regarding the occurrence, physicochemical characteristics, and human health implications of MP contamination, in the present study, two nationwide surveys of MP contamination in mussels (Mytilus galloprovincialis) were conducted in Morocco and Tunisia. The results indicated that MP frequency ranged from 79 % to 100 % in all the analyzed samples. The highest MP density was detected in mussels from Morocco (gills "GI": 1.88 MPs/g ww^-1; digestive glands "DG": 0.92 MPs/g ww^-1) compared to mussels of Tunisia (GI: 1.47 MPs g^{- 1}; DG: 0.79 MPs g^{- 1}). No significant differences in MP density were found between the two organs (GI and DG) for both countries. MPs were predominantly blue and black fibers, and smaller than 1000 μm. Seven polymeric types were identified, of which PET, PP, and PE were the most abundant, accounting for >87 % of all samples. Scanning Electron Microscopy (SEM) coupled with Energy dispersive X-ray (EDX) showed that most MPs have noticeable signs of weathering and inorganic components on their surface. The highest MP daily intake was found in children, while the lowest was estimated in women and men. Moreover, the annual dietary exposure of MPs through mussel consumption was estimated to be 1262.17 MPs/year in Morocco and 78.18 MPs/year in Tunisia. The potential risk assessment of MPs in mussels based on the polymer hazard index (PHI) was estimated in the high-risk levels, implying that MPs may pose health risks to humans. Overall, this research suggests that the consumption of mussels represents a considerable MP exposure route for the Moroccan and Tunisian populations.

Microplastics (MPs) in marine food chains: Is it a food safety issue?

The enormous usage of plastic over the last seven decades has resulted in a massive quantity of plastic waste, much of it eventually breaking down into microplastic (MP) and nano plastic (NP). The MPs and NPs are regarded as emerging pollutants of serious concern. Both MPs and NPs can have a primary or secondary origin. Their ubiquitous presence and ability to sorb, desorb, and leach chemicals have raised concern over their presence in the aquatic environment and, particularly, the marine food chain. MPs and NPs are also considered vectors for pollutant transfer along with the marine food chain, and people who consume seafood have began significant concerns about the toxicity of seafood. The exact consequences and risk of MP exposure to marine foods are largely unknown and should be a priority research area. Although several studies have documented an effective clearance mechanism by defecation, significant aspect has been less emphasized for MPs and NPs and their capability to translocate in organs and clearance is not well established. The technological limitations to study these ultra-fine MPs are another challenge to be addressed. Therefore, this chapter discusses the recent findings of MPs in different marine food chains, their translocation and accumulations potential, MPs as a critical vector for pollutant transfer, toxicology impact, cycling in the marine environment and seafood safety. Besides, the concerns and challenges that are overshadowed by findings for the significance of MPs were covered.

Abundance, composition, and distribution of microplastics in intertidal sediment and soft tissues of four species of Bivalvia from Southeast Brazilian urban beaches

In coastal areas, microplastics (MPs) can deposit in sediment, allowing it to be ingested by benthic organisms, like mussels, thus creating a possible transfer to humans. The aim of this study is to evaluate MPs pollution in sediment as a function of shoreline elevation in two urbanized beaches and to evaluate the abundance/frequency of MPs in 4 different species of bivalves commonly used in the human diet, such as the oyster Crassostrea brasiliana, the mussels Mytella strigata and Perna perna and the clam Tivela mactroides, and identify the polymers via μ-FTIR technique. A total of 3337 MPs were found in this study, of which 1488 were found in the sediment at the five sites analyzed, and 1849 in the bivalve tissues at the two sampling sites. MPs contamination was observed in all sediment samples and species of the pool and in each of the 10 specimens of the four species. Thus, the frequency of contamination by MPs reached 100 % for the analyzed samples. The number of filaments is higher than fragments in sediment samples and in each bivalve species. Regarding types and colors, the blue were greater than fragment-type in sediments and samples. In an effort to classify the polymers via μ-FTIR, our study was able to identify polypropylene, polyethylene and polyethylene terephthalate, besides a great number of cellulose fibers.

A short review on the recent method development for extraction and identification of microplastics in mussels and fish, two major groups of seafood

The prevalence of microplastics in the marine environment poses potential health risks to humans through seafood consumption. Relevant data are available but the diverse analytical approaches adopted to characterise microplastics have hampered data comparison among studies. Here, the techniques for extraction and identification of microplastics are summarised among studies of marine mussels and fish, two major groups of seafood. Among the reviewed papers published in 2018-2021, the most common practice to extract microplastics was through tissue digestion in alkaline chemicals (46 % for mussels, 56 % for fish) and oxidative chemicals (28 % for mussels, 12 % for fish). High-density solutions such as sodium chloride could be used to isolate microplastics from other undigested residues by flotation. Polymer analysis of microplastics was mainly carried out with Fourier-transform infrared (FTIR) spectroscopy (58 % for both mussels and fish) and Raman spectroscopy (14 % for mussels, 8 % for fish). Among these methods, we recommend alkaline digestion for microplastic extraction, and the automated mapping approach of FTIR or Raman spectroscopy for microplastic identification. Overall, this study highlights the need for a standard protocol for characterising microplastics in seafood samples.

Microplastics in the foreshore coastal waters, sediment, and coastal fauna of a highly populated megacity - A study on the effect of anthropogenic discharge on clams

In this study, the microplastics (MPs) abundance, characteristics and their variations across three popular beaches of highly populated and largest megacity of India were documented using clams as an indicator species. The abundance of MPs in clams was 77.39 MPs items/g in soft tissue parts and 198.82 items/individual, while in coastal waters and sediments the abundance was 537.5 ± 95 items/L and 10,568.3 ± 3053.3 items/kg respectively. The observed higher microplastic diversity integrated (MDII) indicates numerous sources contributing to microplastics pollution and higher microplastic index (MPI) indicates greater bioavailability of MPs to clams. The bulk of the microplastics recovered from clams (55.78 %), coastal sediments (52.27 %) and coastal sea waters (54 %) belong to the <100 μm size range, and were identified as LDPE and polypropylene, polyamide and polystyrene. This investigation tried to validate the potential trophic transfer concerns associated with clam intake to both human health and marine ecology.

Micro(nano)plastics in food system: potential health impacts on human intestinal system

Micro(nano)plastics (MNPs) in human food system have been broadly recognized by researchers and have drawn an increasing public attention to their potential health risks, particularly the risk to the intestinal system regarding the long-term exposure to MNPs through food consumption. This study aims to review the environmental properties (formation and composition) of MNPs and MNPs pollution in human food system following the order of food production, food processing and food consumption. The current analytic and identical technologies utilized by researchers are also summarized in this review. In fact, parts of commonly consumed food raw materials, processed food and the way to take in food all become the possible sources for human MNPs ingestion. In addition, the available literatures investigating MNPs-induced intestinal adverse effect are discussed from in vitro models and in vivo mammalian experiments, respectively. Particle translocation, cytotoxicity, damaged gut barrier, intestinal inflammation as well as microbial alteration are mostly reported. Moreover, the practical remediation strategies for MNPs pollution are also illustrated in the last section. This review is expected to provide a research insight for foodborne MNPs and arouse more public awareness of MNPs pollution in food and potential risk for human intestinal health.

Microplastic contamination in commercially important bivalves from the southwest coast of India

Due to the ever-increasing production of plastic litter and its subsequent accumulation as microplastic in the environment, the pollution caused by microplastics is considered as a global menace, especially in the coastal ecosystem. Occurrence of microplastics in water and three commercially important bivalves, Viz. green mussel (Perna viridis), edible oyster (Magallana bilineata) and black clam (Villorita cyprinoides) from five different locations of southwest coast of India was studied. The highest abundance of microplastics was observed in water samples from Periyar River (163.67 items L^-1). Among bivalves, the highest abundance of microplastics was observed in clams from Periyar River (digestive gland: 22.8 g^-1; gill: 29.6 g^-1), whereas the lowest abundance was observed in mussels sampled from Vembanad estuary (digestive gland: 5.6 g^-1; gill: 8.5 g ^-1). Fibers were the most prevalent type of microplastics found in bivalve tissues across each location. Microplastics less than 2 mm were the most prevalent based on size. Polypropylene and high-density polyethylene were the two types of microplastics observed based on the results of Raman spectroscopy. No relationship was observed between shell length, tissue weight and microplastic abundance. A strong positive correlation was observed between the microplastic presence in water and bivalve tissues. The usefulness of sedentary bivalves in assessing the aquatic pollution has been validated through this study.

In vivo oxidative stress responses of the freshwater basket clam Corbicula javanicus to microplastic fibres and particles

Microplastics have been detected in several aquatic organisms, especially bivalves such as clams, oysters, and mussels. To understand the ecotoxicological implication of microplastic accumulation in biota, it is crucial to investigate effects at the physiological level to identify knowledge gaps regarding the threat posed to the environment and assist decision-makers to set the necessary priorities. Typically, xenobiotics elicit an overproduction of reactive oxygen species in organisms, resulting in oxidative stress and cellular damage when not combated by the antioxidative system. Therefore, the present study aimed to establish the impacts of microplastic particles and fibres on the freshwater basket clam Corbicula javanicus. We measured the oxidative stress responses following microplastic exposure as the specific activities of the antioxidative enzymes glutathione S-transferase and catalase. When exposed to polyester fibres from the fleece jackets, the enzyme activities increased in the clams, while the enzyme activities decreased with high-density polyethylene microplastic fragments from bottle caps. All the exposures showed that the adverse effects on the antioxidative response system were elicited, indicating the negative ecotoxicological implications of microplastic pollution.