Microplastics in fresh and processed mussels sampled from fish shops and large retail chains in Italy

Occurrence of microplastics in store-bought fresh and processed clams in Italy

Compared to the large amount of data on wild samples, only a few studies reported microplastic occurrence in store-bought bivalves in which the production chain can be the main contamination route. Microplastic occurrence was herein investigated in 100 samples of store-bought clams sold as fresh or processed (vacuum-frozen or in brine) in Italy. A 10 % KOH was used for soft tissue digestion and FT-IR spectroscopy for polymer identification. A total of 135 potential microplastics ranging in size between 20 μm and 5000 μm were enumerated estimating an annual dietary intake via clam consumption of 59.472 microplastics/person. No significant difference in the average abundance between the two commercial conditions was observed, while a prevalence of smaller particles was detected in processed samples suggesting a detrimental effect of cooking during production. Polyethylene (PE), polyethylene terephthalate (PET), and polystyrene (PS) were identified posing an overall low risk (class II). Microplastic occurrence in store-bought seafood requires additional and specific attention and future studies should investigate microplastic contribution linked to the production chain.

Mangrove mud clam as an effective sentinel species for monitoring changes in coastal microplastic pollution

The worldwide mangrove shorelines are experiencing considerable contamination from microplastics (MPs). Finding an effective sentinel species in the mangrove ecosystem is crucial for early warning of ecological and human health risks posed by coastal microplastic pollution. This study collected 186 specimens of the widely distributed mangrove clam (Geloina expansa, Solander, 1786) from 18 stations along the Leizhou Peninsula, the largest mangrove coast in Southern China. This study discovered that mangrove mud clams accumulated a relatively high abundance of MPs (2.96 [1.61 - 6.03] items·g-1) in their soft tissue, wet weight, as compared to previously reported levels in bivalves. MPs abundance is significantly (p < 0.05 or 0.0001) influenced by coastal urban development, aquaculture, and shell size. Furthermore, the aggregated MPs exhibit a significantly high polymer risk index (Level III, H = 353.83). The estimated annual intake risk (EAI) from resident consumption, as calculated via a specific questionnaire survey, was at a moderate level (990 - 2475, items·g -1·Capita -1). However, the EAI based on suggested nutritional standards is very high, reaching 113,990 (79,298 - 148,681), items·g -1·Capita -1. We recommend utilizing the mangrove mud clam as sentinel species for the monitoring of MPs pollution changing across global coastlines.

The possible impacts of nano and microplastics on human health: lessons from experimental models across multiple organs

The widespread production and use of plastics have resulted in accumulation of plastic debris in the environment, gradually breaking down into smaller particles over time. Nano-plastics (NPs) and microplastics (MPs), defined as particles smaller than 100 nanometers and 5 millimeters, respectively, raise concerns due to their ability to enter the human body through various pathways including ingestion, inhalation, and skin contact. Various investigators demonstrated that these particles may produce physical and chemical damage to human cells, tissues, and organs, disrupting cellular processes, triggering inflammation and oxidative stress, and impacting hormone and neurotransmitter balance. In addition, micro- and nano-plastics (MNPLs) may carry toxic chemicals and pathogens, exacerbating adverse effects on human health. The magnitude and nature of these effects are not yet fully understood, requiring further research for a comprehensive risk assessment. Nevertheless, evidence available suggests that accumulation of these particles in the environment and potential human uptake are causes for concern. Urgent measures to reduce plastic pollution and limit human exposure to MNPLs are necessary to safeguard human health and the environment. In this review, current knowledge regarding the influence of MNPLs on human health is summarized, including toxicity mechanisms, exposure pathways, and health outcomes across multiple organs. The critical need for additional research is also emphasized to comprehensively assess potential risks posed by degradation of MNPLs on human health and inform strategies for addressing this emerging environmental health challenge. Finally, new research directions are proposed including evaluation of gene regulation associated with MNPLs exposure.

Assessing the inconsistency of microplastic measurements in foods and beverages

The widespread occurrence of microplastics (MPs) in the food chain has gained substantial recognition as a pressing concern, highlighting the inevitability of human exposure through ingestion of foodborne MPs, coupled with the release of MPs from plastic packaging. However, there are notable disparities in the reported numbers of MPs in foods and beverages, warranting a thorough investigation into the factors contributing to these discrepancies. Table salt is one of the major sources of MPs, and there was an approximately hundred-fold difference between the reviewed studies that reported the highest and lowest number of MPs. In addition, more noticeable discrepancies were discovered between studies on MPs released from teabags. One study reported that approximately 15 billion MPs were released into a cup of tea from a single teabag, whereas another research paper found only approximately 106.3 ± 14.6 MP/teabag after brewing. This comprehensive review focuses on the inconsistencies observed across studies examining MPs, shedding light on the plausible factors underlying these variations. Furthermore, the review outlines areas in analytical procedures that require enhancement and offers recommendations to promote accuracy and standardization in future research efforts, such as employing analytical methods capable of confirming the presence of MPs, using appropriate filter sizes, considering representative sample sizes when extrapolation is involved, and so on. By pinpointing the detection processes leading to the inconsistent results observed in MP studies, this comparative analysis will contribute to the development of reliable analytic methods for understanding the extent of microplastic contamination in the human food chain.

The Occurrence of Microplastics in Donax trunculus (Mollusca: Bivalvia) Collected along the Tuscany Coast (Mediterranean Sea)

Microplastics (MPs) (0.1 µm-5 mm particles) have been documented in oceans and seas. Bivalve molluscs (BMs) can accumulate MPs and transfer to humans through the food chain. BMs (especially mussels) are used to assess MPs' contamination, but the genus Donax has not been thoroughly investigated. The aim of this study was to detect and characterize MPs in D. trunculus specimens collected along the Tuscan coast (Italy), and to assess the potential risk for consumers. The samples (~10 g of tissue and intervalval liquid from 35 specimens) were digested using a solution of 10% KOH, subjected to NaCl density separation, and filtered through 5 μm pore-size filters. All items were morphologically classified and measured, and their mean abundance (MA) was calculated. Furthermore, 20% of them were analyzed by Raman spectroscopy and, based on the obtained results, the MA was recalculated (corrected MA) and the annual human exposure was estimated. In the 39 samples analyzed, 85 items fibers (n = 45; 52.94%) and fragments (n = 40; 47.06%) were found. The MA was 0.23 ± 0.17 items/grww. Additionally, 83.33% of the items were confirmed as MPs (polyethylene and polyethylene terephthalate). Based on the correct MA (0.18 MPs/grww), D. trunculus consumers could be exposed to 19.2 MPs/per capita/year. The health risk level of MPs was classified as level III (moderate).

Assessing micro and nanoplastics toxicity using rodent models: Investigating potential mitochondrial implications

Mitochondria's role as a central hub in cellular metabolism and signaling cascades is well established in the scientific community, being a classic marker of organisms' response to toxicant exposure. Nonetheless, little is known concerning the effects of emerging contaminants, such as microplastics, on mitochondrial metabolism. Micro- and nanoplastics present one of the major problems faced by modern societies. What was once an environmental problem is now recognized as an one-health issue, but little is known concerning microplastic impact on human health. Indeed, only recently, human exposure to microplastics was acknowledged by the World Health Organization, resulting in a growing interest in this research topic. Nonetheless, the mechanisms behind micro- and nanoplastics toxicity are yet to be understood. Animal models, nowadays, are the most appropriate approach to uncovering this knowledge gap. In the present review article, we explore investigations from the last two years using rodent models and reach to find the molecular mechanism behind micro- and nanoplastics toxicity and if mitochondria can act as a target. Although no research article has addressed the effects of mitochondria yet, reports have highlighted molecular and biochemical alterations that could be linked to mitochondrial function. Furthermore, certain studies described the effects of disruptions in mitochondrial metabolism, such as oxidative stress. Micro- and nanoplastics may, directly and indirectly, affect this vital organelle. Investigations concerning this topic should be encouraged once they can bring us closer to understanding the mechanisms underlying these particles' harmful effects on human health.

Micro(nano)plastics in commercial foods: A review of their characterization and potential hazards to human health

Micro (nano)plastics (MNPs) are pollutants of worldwide concern for their ubiquitous environmental presence and associated impacts. The higher consumption of MNPs contaminated commercial food can cause potential adverse human health effects. This review highlights the evidence of MNPs in commercial food items and summarizes different sampling, extraction, and digestion techniques for the isolation of MNPs, such as oxidizing digestion, enzymatic digestion, alkaline digestion and acidic digestion. Various methods for the characterization and quantification of microplastics (MPs) are also compared, including μ-Raman spectroscopy, μ-Fourier transform infrared spectroscopy (FTIR), thermal analysis and Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). Finally, we share our concerns about the risks of MNPs to human health through the consumption of commercial seafood. The knowledge of the potential human health impacts at a subcellular or molecular level of consuming mariculture products contaminated with MNPs is still limited. Moreover, MNPs are somewhat limited, hard to measure, and still contentious. Due to the nutritional significance of fish consumption, the risk of exposure to MNPs and the associated health effects are of the utmost importance.

Anthropogenic particles in the muscle, gill, and gastrointestinal tract of marine fish sold for human consumption

Contamination of marine fish with the widespread distribution of anthropogenic particles (APs) becomes increasingly severe, however, related research on the assessment of the occurrence of APs in the edible tissue of commercial fish is scarce. The objective of this study was to evaluate the features of APs pollution based on seven species of commercial marine fish (n = 12 per species) and investigate the accumulation of APs in different tissues of fish namely gill and gastrointestinal tract (GIT), and muscle. The results show that a total of 62 APs were detected in 33 out of 84 (39.3%) fresh fish samples using a micro-Raman spectrometer which in particular is characterized by a blue color, shape-like fiber, and size smaller than 0.5 mm. Among them, 47 (75.8%) particles were identified as pigments such as indigo, chrome yellow-orange, disperse yellow, and pigment black. The other 11 (17.7%) particles were plastic including polypropylene (PP), polyethylene terephthalate (PET), and polyacrylonitrile (PAN). And the rest 4 (6.5%) particles were anthropogenic cellulose fibers. Muscle tissue from six species of fish was detected to contain a total of 15 APs. Based on the total mean of APs found in fish muscle (0.018 AP items/g tissue) and on the consumption of fish in Malaysia (59 kg/capita/year), the estimated human intake of APs through fish consumption was 1062 AP items/year/capita. Considering that food consumption is an important route of human exposure to APs, it is suggested to add APs testing into the guidelines of food safety management systems and adopt mitigation measures to reduce the APs pollution in food.

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.

Preliminary survey on the occurrence of microplastics in bivalve mollusks marketed in Apulian fish markets

Microplastics (MPs) are a relevant threat to food safety because they are ingested by humans through various foods. Bivalves are at high risk of microplastic contamination due to their filter-feeding mechanism and pose a risk to consumers as they are ingested whole. In this work, microplastics were detected, quantified, identified, and classified in samples of mussels (Mytilus galloprovincialis) and oysters (Crassostrea gigas) marketed in the Apulia region. The total number of plastic debris was 789 particles in the mussel samples and 270 particles in the oyster samples, with size ranging from 10 to 7350 μm. Fragments with size within the category of 5-500 μm were the predominant findings in both species, with blue as the predominant color in mussels and transparent in oysters; most of the debris was polyamide and nylon polymers in the mussels and chlorinated polypropylene in the oysters. These results show that mussel and oyster samples purchased at fish markets are contaminated with microplastics. The sources may be diverse and further studies are needed to assess the impact of the marketing stage on microplastic contamination in bivalves to better define the human risk assessment associated with microplastic exposure from bivalves consumption.

Microplastics in canned, salt-dried, and instant sea cucumbers sold for human consumption

Determining the amount of microplastics (MPs) in food is key to clarifying their potential toxicity to humans. Here, we collected canned, instant, and salt-dried sea cucumbers Apostichopus japonicus, the most valued sea cucumbers, from Chinese markets to determine their content of MPs. Sea cucumbers contained MPs in the range of 0-4 MP individual^-1, an average of 1.44 MP individual^-1, and 0.081 MP g^-1. Accordingly, consuming 3 g of sea cucumbers could result in an exposure risk of an average of 0.51 MPs, 0.135 MPs, and 0.078 MPs day^-1 for canned, instant, and salt-dried sea cucumbers, respectively. MPs were in size range of 12-575 μm, and fibrous shape was dominant. Furthermore, among the five polymers identified, polypropylene showed the highest energy binding with two catalysts engaged in organic chemical oxidation. This study extends the knowledge regarding MPs occurrence in food and provides a theoretical basis for MPs toxicity in humans.

Distribution of Micro-Nano PS, DEHP, and/or MEHP in Mice and Nerve Cell Models In Vitro after Exposure to Micro-Nano PS and DEHP

Polystyrene (PS) and di-(2-ethylhexyl) phthalate (DEHP) exist widely in the environment. However, their distribution in organisms remains unclear. We used three sizes (50 nm, 500 nm, and 5 μm) of PS and DEHP to study the distribution and accumulation of PS, DEHP, and mono(2-ethylhexyl) phthalate (MEHP) in mice and nerve cell models (HT22 and BV2 cells) and their potential toxicity. Results showed that PS entered the blood of mice, and the distribution of different particle sizes in different tissues was different. After the combined exposure to PS and DEHP, PS carried DEHP, which significantly increased the DEHP content and MEHP content and the highest content of MEHP was in the brain. With the decrease in PS particle size, the contents of PS, DEHP, and MEHP in the body increased. The levels of inflammatory factors were increased in the serum of the PS or/and DEHP group. In addition, 50 nm polystyrene can carry MEHP into nerve cells. These results suggest for the first time that PS and DEHP combined exposure can induce systemic inflammation, and the brain is an important target organ of PS and DEHP combined exposure. This study may serve as a reference for further evaluation of the neurotoxicity induced by combined exposure to PS and DEHP.

Occurrence and Characterization of Microplastics in Commercial Mussels (Mytilus galloprovincialis) from Apulia Region (Italy)

Microplastics are a ubiquitous pollutant whose spreading is a growing concern worldwide. They can pose a threat to food safety and consumer health as they are ingested through various foods. Bivalves are considered the most contaminated, as they filter large amounts of seawater and enter consumers’ diet ingested whole. The aim of this study was to detect, quantify, identify and classify microplastics in mussels (Mytilus galloprovincialis) marketed in fishery stores in Bari and its surroundings (Apulia, Italy). A total of 5077 particles were isolated from our samples, with an average value of 1.59 ± 0.95 MPs/g and 6.51 ± 4.32 MPs/individual. Blue fragments, sized 10–500 µm, were the prevalent findings; most of them belonged to Polyamide (PA) polymers. The results of this study help to show that mussels represent a source of microplastics for consumers and a direct risk to their health, even considering that they may contain many chemical compounds and microorganisms that may or may not be pathogenic to humans. Further research is needed to assess the role of commercialization in bivalve molluscs contamination.

Quantification analysis of microplastics released from disposable polystyrene tableware with fluorescent polymer staining

Ingesting microplastics (MPs) from plastic tableware is an important source of health risk to human bodies. However, the comprehensive information of MPs released from disposable tableware has not been explored. Herein, a new visual quantification method for polystyrene MPs is proposed with carbon nitride fluorescent polymers staining, which can overcome the disadvantages of high signal background and photobleaching derived from organic dyes staining. Combining with fluorescence microscope and ImageJ software, the quantity, shape, and size distribution of MPs carried by the brand-new disposable polystyrene tableware (DPT) samples before usage and released from the clean DPT samples in different simulated usage scenes were studied. The brand-new DPT samples were found to carry a large number of MPs particles and the clean DPT samples could release MPs during usage. Fiber and fragment are the main morphology of the detected MPs and fiber accounts for 45-52 %. The particles with size <50 μm are the majority of the detected MPs and the distribution fraction of MPs particles is gradually decreased with the raising of particle size within 50 μm. The released MPs particles are increased with the raising of contact time and temperature, and greatly boosted for the DPT samples with cracks. The DPT samples are more like to release MPs in weak acidic condition (pH 4.0) than in weak alkaline (pH 8.3) and neutral (pH 7.0) conditions. The obtained results help to assess the food safety of tack-out food and the health risk of MPs exposure to human.

Microplastics in mussels from the Boka Kotorska Bay (Adriatic Sea) and impact on human health

This study evaluated the microplastic abundance, shape, color, size and chemical composition of microplastic in mussels and estimated human exposure to microplastic through consumption of mussels collected from Boka Kotorska Bay (Adriatic coast of Montenegro). Microplastic was found in 53.3% of the studied mussels, with an average microplastic abundance of 2.53 ± 1.1 items/individual. Most of the ingested microplastic were fibers (63.7%), which were blue in color. FT-IR revealed that 98% of the examined particles were plastic, with seven polymers identified, of which polyethylene, polypropylene, and polyethylene terephthalate were the most abumdant polymers in mussels. Three of the polymers detected in mussels (polyamide, polyvinyl chloride and polystyrene) are classified as hazardous by the European Chemical Agency with warning or danger signals. With one serving of mussels, consumers would ingest 22.7 microplastic particles, while the annual dietary intake of microplastic via consumption of mussels was estimated at 99 MP/year.

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.

Microplastics and plastics-associated contaminants in food and beverages; Global trends, concentrations, and human exposure

Microplastics has become a global concern due to their ubiquitous presence which poses unavoidable human exposure risks. Geographical distribution and yearly trends of research on microplastics, food, and beverages do not exist. Thus, no overall account is available regarding the presence of microplastics and plastics-associated contaminants in food and beverages. Hence, this attempt is to review the geographical distribution of studies through a brief bibliometric analysis and the plastics-associated contaminants including plasticizers and microplastics in food and beverages. Estimated microplastic consumption has been listed for the pool of publications reviewed here. Further, this review discusses the ingestion potency of micropollutants associated with microplastics, possible health impacts, and existing challenges. Global trend in research exponentially increased after 2018 and China is leading. Studies on microplastics were limited to a few beverages and food; milk, beer, tea, refreshing drinks, salt, sugar, honey, etc., whereas seafood and drinking water have been extensively studied. Publications on plastic-additives were reported in two ways; migration of plastic-additives from packaging by leaching and the presence of plastic-additives in food and beverages. Bisphenol A and bis(2-Ethylhexyl) phthalate were the most frequently reported both in food and beverages. Exposure of packaging material to high temperatures predominantly involves plastic-additive contamination in food and beverages. Microplastics-bound micropollutants can also be ingested through food and beverages; however, a lack of knowledge exists. The complex matrix of food or beverages and the absence of standard procedures for analysis of microplastics and micropollutants exist as challenges. More investigations on the presence of microplastics and plastic-additives in food and beverage are urgent needs to a better assessment of potential human exposure and human health risk.

Nano- and microplastics: a comprehensive review on their exposure routes, translocation, and fate in humans

Contamination of the environment with nano-and microplastic particles (NMPs) and its putative adverse effects on organisms, ecosystems, and human health is gaining increasing scientific and public attention. Various studies show that NMPs occur abundantly within the environment, leading to a high likelihood of human exposure to NMPs. Here, different exposure scenarios can occur. The most notable exposure routes of NMPs into the human body are via the airways and gastrointestinal tract (GIT) through inhalation or ingestion, but also via the skin due to the use of personal care products (PCPs) containing NMPs. Once NMPs have entered the human body, it is possible that they are translocated from the exposed organ to other body compartments. In our review article, we combine the current knowledge on the (1) exposure routes of NMPs to humans with the basic understanding of the potential (2) translocation mechanisms into human tissues and, consequently, their (3) fate within the human body. Regarding the (1) exposure routes, we reviewed the current knowledge on the occurrence of NMPs in food, beverages, personal care products and the air (focusing on indoors and workplaces) and found that the studies suggest an abundant presence of MPs within the exposure scenarios. The overall abundance of MPs in exposure matrices relevant to humans highlights the importance of understanding whether NMPs have the potential for tissue translocation. Therefore, we describe the current knowledge on the potential (2) translocation pathways of NMPs from the skin, GIT and respiratory systems to other body compartments. Here, particular attention was paid to how likely NMPs can translocate from the primary exposed organs to secondary organs due to naturally occurring defence mechanisms against tissue translocation. Based on the current understanding, we conclude that a dermal translocation of NMPs is rather unlikely. In contrast, small MPs and NPs can generally translocate from the GIT and respiratory system to other tissues. Thus, we reviewed the existing literature on the (3) fate of NMPs within the human body. Based on the current knowledge of the contamination of human exposure routes and the potential translocation mechanisms, we critically discuss the size of the detected particles reported in the fate studies. In some cases, the particles detected in human tissue samples exceed the size of a particle to overcome biological barriers allowing particle translocation into tissues. Therefore, we emphasize the importance of critically reading and discussing the presented results of NMP in human tissue samples.

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.

Potential risk of microplastics in processed foods: Preliminary risk assessment concerning polymer types, abundance, and human exposure of microplastics

The occurrence of microplastics (MPs) has been widely reported in human foodstuffs, and their potential negative effects on human health have been brought into focus. Processed foods are more susceptible to MPs as contamination can be introduced during processing and packaging. However, the risk posed by MPs in processed foods remained unclear. This work aims to critically review the available data for MPs in 11 types of possessed foods and to conduct a preliminary risk assessment of MPs in processed foods. For a comprehensive evaluation, three indicators were selected and determined, namely chemical risk, pollution load, and estimated daily intake (EDI). Our results suggest that nori has the highest chemical risk, followed by canned fish, beverages, table salt, and other food items. In the case of pollution load, nori and milk fall into the risk category of Ⅳ and Ⅲ respectively. Table salts, bottled water, and sugar exhibited lower MPs pollution load (risk category of Ⅱ), whereas the pollution loads of other foods were calculated to be category Ⅰ. Moreover, a correlation between the pollution load of sea salts and MPs pollution level in ambient seawater was found. Regarding EDI of MPs from different processed foods, MPs intakes through bottled water (14.3 ± 3.4 n kg^-1 d^-1) and milk (6.6 ± 2.4 n kg^-1 d^-1) are significantly higher than that of the other foods (< 1 n kg^-1 d^-1). The probabilistic estimation of MPs daily intake indicated that children (19.7 n kg^-1 d^-1) are at a higher health risk than adults (female: 17.6 n kg^-1 d^-1, male: 12.6 n kg^-1 d^-1). Nevertheless, the exposure dose used in toxicological studies was about 10 times higher than the MPs intake via processed foods. Therefore, we argued that MPs in processed foods only carry limited risk. Overall, this study would provide the basis for risk management of MPs in processed food products.

Perfluorooctane sulfonate (PFOS) enhanced polystyrene particles uptake by human colon adenocarcinoma Caco-2 cells

As microplastics and nanoplastics (MNPs) are widely distributed in the environment and can be transferred to human body through food chain, their potential impact on human health is of great concern. Perfluorooctane sulfonate (PFOS) is persistent, bioaccumulative and can be adsorbed by MNPs. However, there are few studies on the combined human health effects of MNPs with PFOS. In this study, the effects of polystyrene (PS) particles and PFOS on human colon adenocarcinoma cell Caco-2 were investigated in vitro to explore the combined toxicity from cellular level, and the toxic mechanism was further illustrated. Results showed that the presence of PFOS significantly increased the cell uptake of PS nanoparticles by >30 %, which is related to variations of the surface properties of PS particles, including the decrease of hydration kinetic diameter, the rise of surface potential and the adsorption of hydrophobic PFOS molecules. The toxic effect of PFOS was weakened in the presence of PS particles under low PFOS concentration (10 μg/mL), which is because the bioavailability of PFOS was reduced after adsorption. PS particles with small particle size (20 nm) showed higher cell uptake and ROS production, while PS particles with large particle size (1 μm) led to higher lipid oxidation degree and related membrane damage as well as mitochondrial stress. This study provides the first evaluation of combined toxicity of MNPs and PFOS on human intestinal cells, in order to support the risk assessment of combined pollution of MNPs and PFOS on human health.

How does bivalve size influence microplastics accumulation?

Microplastics (wasted plastic particles < 5 mm in diameter) are ubiquitously distributed in the marine environment. Filter-feeding and low trophic level bivalves are vulnerable to microplastics accumulation from the surrounding depositional environment, thereby threatening both ecological health and human food safety. Microplastics had been detected in lots of coastal Bivalvia species. However, the influence of biological morphology on the mechanism of microplastics accumulation is not clear. There is also a knowledge gap of which species are preferred for commercial consumption, which creates loopholes in risk identification for food safety. A survey on a commercial popular eaten but under-researched hard clam (Meretrix meretrix; Linnaeus, 1758) from a famous fishery port city in southern China was carried out to comprehensively analyze shell size influence on microplastics accumulation in bivalves and consequently, human intake risk via bivalve consumption. Detected microplastics count in per individual (MCI) was 24.64 ± 19.11 items · individual^-1, and microplastics count per gram (MCG; wet weight with shell) was 0.66 ± 0.54 items · g^-1. When the shell width grew by 1 mm, MCI increased by 1.01 times, but MCG decreased by 0.97 times. Dominant microplastics characteristics found in this study was fiber and fragment. Sizes ranged from 25 to 150 μm, and dark colors (black, red, and blue) were found. The mostly common polymers were polyethene (PE, 40%), polyethylene terephthalate (PET, 23%), and polypropylene (PP, 18%). Estimated annual intake (EAI) risk of microplastics via hard clam consumption by residents was 6652.26 ± 5327.28 items · year ^-1 · person ^-1. The microplastics in bivalves and EAI was relatively high. When shell width grew by 1 mm, EAI decreased by 0.97 times. Therefore, eating a fixed amount of larger hard clams with a relatively low amount of microplastics can reduce EAI risk for consumers. A systematic investigation of emission sources along main coast, where bivalve production is prominent will be useful for food safety control in this region.

Identification and Evaluation of Microplastics from Tea Filter Bags Based on Raman Imaging

Microplastic (MP) contamination is a public issue for the environment and for human health. Plastic-based food filter bags, including polyethylene terephthalate, polypropylene, nylon 6 (NY6), and polyethylene, are widely used for soft drink sub-packaging, increasing the risk of MPs in foods and the environment. Three types of commercially available filter bags, including non-woven and woven bags, were collected, and MPs released after soaking were mapped using Raman imaging combined with chemometrics. Compared with peak area imaging at a single characteristic peak, Raman imaging combined with direct classical least squares calculation was more efficient and reliable for identifying MP features. Up to 94% of the bags released MPs after soaking, and there was no significant correlation with soaking conditions. Most MPs were tiny fragments and particles, and a few were fibrous MPs 620–840 μm in size. Woven NY6 filter bags had the lowest risk of releasing MPs. Source exploration revealed that most MPs originated from fragments and particles adsorbed on the surface of bags and strings. The results of this study are applicable to filter bag risk assessment and provide scientific guidance for regulating MPs in food.

Microplastics in global bivalve mollusks: A call for protocol standardization

A growing body of evidence shows that microplastic pollution is ubiquitous in bivalve mollusks globally and is of particular concern due to its potential impact on human health. However, non-standardized sampling, processing, and analytical techniques increased the difficulty of direct comparisons among existing studies. Based on 61 peer-reviewed papers, we summarized the current knowledge of microplastics in bivalve mollusks globally and provided an in-depth analysis of factors affecting the outcome of microplastic data, with the main focus on the effects of different species and methodologies. We found no significant differences in microplastic abundance among genera from the same family but significant differences among bivalve families, indicating habitats play an important role in microplastic ingestion by bivalve mollusks. This also provided foundational knowledge for using epifaunal and infaunal bivalves to monitor microplastic pollution in water and sediment, respectively. Recommendations for microplastic monitoring protocol in bivalve mollusks were proposed according to the results of this review, covering (i) a sample size of at least 50 bivalves in the study area, (ii) the use of 10 % KOH as the digestion solution, and (iii) the pore size of a filter membrane of < 5 µm. Acknowledging the need for a standard procedure, more efforts towards protocol standardization used in long-term and large-scale microplastic monitoring programs in bivalve mollusks are needed.

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.

Occurrence of microplastics in gastrointestinal tract of fish from the Gulf of Guinea, Ghana

Over the past decades, there has been a growing concern about microplastics pollution in global aquatic habitats and its potential impact on human health. This study was carried out to determine the presence of microplastics in fish of economic importance in Ghana. Microplastics were found to be abundant in all investigated samples, with 68 % of the fishes contaminated with microplastics and a total of 133 plastic items identified in the fish. The presence of fibers, black coloured particles, and microplastics in the size range of 0.5-1.0 mm was the most abundant in the samples examined. Three polymers specifically, polyethylene, polyvinyl acetate, and polyamide were identified in the study. The presence of microplastics in the fishes investigated may pose severe ecological and health concerns, and hence comprehensive policies targeted at preventing plastic pollution of Ghana's maritime environment is warranted.

Effects of cooking methods on microplastics in dried shellfish

Many studies have reported the occurrence of microplastics in live shellfish intended for human consumption. However, far fewer studies have been conducted on dried shellfish from supermarkets or fishery markets. In this study, the characteristics of microplastics in six kinds of dried shellfish products following different cooking treatments were investigated. Dietary exposure to microplastics in dried shellfish was estimated using the consumption rate of seafood among different age groups. Microplastics were detected in all the uncooked, dried shellfish products, ranging from 0.3 to 4.2 items/g. Fibres accounted for more than 80% of microplastics in razor clams, winkles, and scallops. The proportion of microplastics smaller than 1 mm in size ranged from 57.1% to 89.7% of the total microplastics found in dried shellfish. The polymer types included polyethylene terephthalate (PET), rayon, polyester, nylon, polypropylene (PP), cellophane (CP), and polyethylene (PE). Principal component analysis (PCA) showed that the sizes and shapes of microplastics in scallops were more susceptible to alteration by different cooking methods. Steaming and frying significantly reduced the abundance of microplastics in razor clams. In addition, significantly fewer microplastics were found in scallop products after boiling and steaming than were found in fried scallop products. The estimated dietary intake of microplastics for infants was the highest among the age groups considered (3.05 items/kg(bw)/day). Accordingly, frying was suggested for cooking mussels, boiling for clams and winkles, and steaming for scallops. Combining risks from ingesting plastics and plastic additives, steaming is suggested as the best method to cook shellfish.

Optimization of an Analytical Protocol for the Extraction of Microplastics from Seafood Samples with Different Levels of Fat

Marine organisms are affected by the ubiquitous occurrence of microplastics (MPs) in the environment. Several protocols have been described to extract and quantify MPs in seafood, although their complex matrices, with high level of fat, can compromise the efficiency of MPs extraction. To solve this issue, the present study aimed to develop a detailed methodology suitable to process seafood samples with different levels of fat, namely fish and molluscs, from fresh and canned sources, including the immersive liquids from the cans. Sample digestion was tested using different solutions (10% KOH, 30% H₂O₂), temperatures (40 °C, 65 °C) and incubation times (24, 48, 72 h). For fat removal, three detergents (two laboratory surfactants and a commercial dish detergent) and 96% ethanol were tested, as well as the manual separation of fat. The methodology optimized in this study combined a digestion with 30% H₂O₂ at 65 °C, during 24 to 48 h, with a manual separation of the fat remaining after the digestion. All steps from the present methodology were tested in six types of polymers (PE-LD, PET, PE, AC, PS, and lycra), to investigate if these procedures altered the integrity of MPs. Results showed that the optimized methodology will allow for the efficient processing of complex seafood samples with different fat levels, without compromising MPs integrity (recoveries rate higher than 89% for all the polymers tested).

Depuration of anthropogenic particles by Pacific oysters (Crassostrea gigas): Feasibility and efficacy

Anthropogenic particles (APs) generated from both natural and synthetic materials are widespread in the aquatic environment and contaminate seafood products, including shellfish. Depuration, involving the placement of filter-feeding shellfish in clean water for a period of time, often several days, is used to reduce contaminant concentrations, but the practicality of its use by the shellfish industry for APs has not yet been examined. In the present study, cultured adult Pacific oysters (Crassostrea gigas) were depurated for 10 days in a facility with limited airflow and filtered seawater. On average, there was a 73 % reduction in oyster AP concentration after 5 days, but no further reduction at 10 days, potentially due to the difficulty in depurating some particles or to re-contamination from the experimental environment. Long-term feasibility for industry will depend on future guidelines for safe AP consumption levels and the practicality and financial feasibility of creating and running clean facilities.

Extraction, identification, and environmental risk assessment of microplastics in commercial toothpaste

Microplastics in personal care and food products are given much importance globally due to the adverse impact of microplastics on living beings. In the present study, microplastics from ten different commercially sold toothpaste in India were extracted by vacuum filtration and characterized with microscopic and Fourier-transform infrared spectroscopic analyses. Results revealed that colorless fragments and fibers were the microparticle types of common occurrence which ranged from 0.2 to 0.9% weight in the toothpaste with an abundance range of 32.7-83.2%. Fifty percent of the toothpaste samples showed more than 50% microplastic particle abundance indicating that the microplastic plastic particles were added by the manufacturers. The minimum size of microplastics recorded in the present study was 3.5 μm with a maximum size exceeding 400 μm. The maximum number of microplastics in the toothpaste was 167, 508 and 193 respectively, distributed in the size range of <100 μm, 100-400 μm, and >400 μm. The present study recorded four major polymer types, viz., cellophane, polypropylene, polyvinyl chloride, and polyamide in the toothpaste samples. Surprisingly, polyethylene-a common polymer reported in toothpaste was not traced in the present samples. Regarding the Indian context, the current study is a new addition to the knowledge of the occurrence of microplastics in toothpaste. The average annual addition of microplastics into the environment through toothpaste was calculated as 1.4 billion g/year for India, posing a significant threat to the environment.

Current Insights into Potential Effects of Micro-Nanoplastics on Human Health by in-vitro Tests

Humans are exposed to micro and nanoplastics (MNPLs) through inhalation, ingestion and, to a lesser extent, dermal contact. In recent years, new insights indicate the potential of MNPLs to cause damages to human health. Particle toxicity can include oxidative stress, inflammatory lesions, and then increased internalization or translocation through tissues. On the other hand, plastic additives are used in plastic particles, once internalized, can release toxic substances. It is noteworthy that the potential effects of MNPLs encompass a wide range of polymers and chemical additives, showing various physicochemical and toxicological properties, and the size, shape and surface properties are other variables influencing their effects. In spite of the research carried out recently, MNPLs research is in its early stages, and further investigation is required. In this review article, the knowledge of human exposure routes and the recent results on the toxicological effects of MNPLs in human health are presented and discussed. Finally, the current limitations and the main gaps in the body of knowledge are summarised.

Investigation of microplastics in edible wild mussels from İzmir Bay (Aegean Sea, Western Turkey): A risk assessment for the consumers

The presence of microplastics (MPs) was determined in Mediterranean mussel (Mytilus galloprovincialis Lamarck, 1819) and grooved carpet shell (Ruditapes decussatus Linnaeus, 1758) together with water samples from in İzmir Bay (Aegean Sea, Western Turkey). A total of 895 MPs from Karşıyaka (Station 1), and 787 MPs from Gülbahçe (Station 2) were detected in 60 mussel samples, giving a total content of 1682 MPs. In water samples, a total of 545 MPs were detected in samples from Station 1 and 1287 MPs in samples from Station 2 (1832 MPs total). The amount of MPs in water samples was less in Station 1 than in Station 2. This difference is probably caused by Çiğli Wastewater Treatment Plant (WWTP) located near Station 1. Public health risk assessment on the consumption of the species M. galloprovincialis revealed that 70.82 items person^-1 year^-1 MPs through this species could enter consumers' digestive systems.

Microplastics and Nanoplastics: Emerging Contaminants in Food

As current concerns about food safety issues around the world are still relatively serious, more and more food safety issues have become the focus of people's attention. What's more serious is that environmental pollution and changes in human lifestyles have also led to the emergence of contaminants in food, microplastics (MPs) and nanoplastics (NPs) being typical representatives. MPs and NPs (M/NPs) in food are gradually becoming recognized by regulatory authorities and the public. Most published reviews on M/NPs have been focused on the environmental ecosystems. In those papers, it is only sporadically mentioned that M/NPs can also appear in food. As far as we know, there has not been a systematic review of the pollution and existing status of M/NPs in food. This Review focuses on the harmfulness of M/NPs, the ways in which M/NPs contaminate food, the residual amount of M/NPs in food, and the current analysis and detection methods for M/NPs in food. Current analysis and detection methods have problems such as being time-consuming, involving cumbersome operation, and giving poor accuracy. In the future, it will be necessary to increase the research on methods for efficient and sensitive separation and detection of M/NPs in food. Finally, it is hoped that this Review will arouse more people's awareness of and attention to the seriousness of M/NPs in food.