Migration of (non-) intentionally added substances and microplastics from microwavable plastic food containers

Phytolacca americana extract as a quality-enhancing factor for biodegradable double-layered films based on furcellaran and gelatin - Property assessment

For the first time, novel active double-layered films based on furcellaran (FUR) and gelatin (GEL) with the addition of Phytolacca americana (PA) extract were obtained. The 1st layer consisted of FUR and GEL, while the aqueous extract of P. americana berries was added in three different concentrations to the 2nd FUR-based layer. The films were characterised by good mechanical (TS range of 0.0011-0.0013 MPa, EAB range between 30.38 %-33.51 %) and water properties (WVTR range of 574.74-588.49 g/m2xd). Structural analysis (SEM and AFM) confirmed good film structure: regular, without cracks or air bubbles. The films showed antioxidant activity tested via the Folin-Ciocâlteu method (4.77-20.70 mg GAExg-1), FRAP assay (0.18-3.40 mM TExg-1) and CUPRAC assay (48.63-53.99 mM TExg-1). The film with the highest PA concentration (6 %) demonstrated the ability to neutralise free radicals, DPPH• and ABTS2+•, at the levels of 1.97 % and 17.34 %, respectively. The ecotoxicity test performed on Lepidium sativum seeds confirmed the lack of ecotoxic film aspects. The biodegradation test indicated that the films are biodegradable. The obtained films can be a good alternative to plastic packaging films (used in the food packaging industry), which are currently a global problem related to the development of post-consumer plastics.

Plastic takeaway food containers may cause human intestinal damage in routine life usage: Microplastics formation and cytotoxic effect

The microplastics and organic additives formed in routine use of plastic takeaway food containers may pose significant health risks. Thus, we collected plastic containers made of polystyrene, polypropylene, polyethylene terephthalate, polylactic acid and simulated two thermal usages, including hot water (I) and microwave treatments (M). Nile Red fluorescence staining was developed to improve accurate counting of microplastics with the aid of TEM and DLS analysis. The quantity of MPs released from thermal treatments was determined ranging from 285.7 thousand items/cm2 to 681.5 thousand items/cm2 in containers loaded with hot water with the following order: IPS>IPP>IPET>IPLA, while microwave treatment showed lower values ranging from 171.9 thousand items/cm2 to 301.6 thousand items/cm2. In vitro toxicity test using human intestinal epithelial Caco-2 cells indicated decrease of cell viability in raw leachate, resuspended MPs and supernatants, which might further lead to cell membrane rupture, ROS production, and decreased mitochondrial membrane potential. Moreover, the leachate inhibited the expression of key genes in the electron transport chain (ETC) process, disrupted energy metabolism. For the first time, we isolate the actually released microplastics and organic substances for in vitro toxicity testing, and demonstrate their potential impacts to human intestine. SYNOPSIS: Plastic take-out containers may release microplastics and organic substances during daily usage, both of which can cause individual and combined cytotoxic effects on human colon adenocarcinoma cells Caco-2.

Releasing characteristics of toxic chemicals from polystyrene microplastics in the aqueous environment during photoaging process

Microplastics (MPs) are pervasive in the environment and inevitably undergo photoaging due to UV irradiation. This study delved into the dynamic releasing and transformation process of toxic chemicals from polystyrene microplastics (PS MPs) during photoaging, a subject that remains underexplored. It was revealed that photoaging led to substantial alterations in the physicochemical properties of PS MPs, initiating polymer chain scission and facilitating the release of a large number of toxic chemicals, including numerous organic compounds and several inorganic compounds. The kinetic analysis revealed a dynamic release pattern for PS MPs, where under varying UV intensities (2, 5, and 10 mW/cm2), the release rate (kDOC) initially increased and then decreased, peaking at a total irradiation energy of approximately 7 kW·h/m2. Furthermore, chemicals in leachate were transformed into compounds with smaller molecular weight, higher oxidized and greater unsaturated state over the prolonged photoaging. This transformation was primarily attributed to two reasons. Firstly, the aged PS MPs released chemicals with higher oxidized state compared to the pristine MPs. Secondly, the chemicals previously released underwent further reactions. Besides, among the complex leachate generated by aged PS MPs, the organic chemicals characterized by small molecular weight and high oxidized state exhibited notable acute toxicity, whereas heavy metal ions showed lesser toxicity, and anions were non-toxic. This study shed more light on the photoaging process of PS MPs, releasing characteristics of organic chemicals, and the potential environmental risks associated with plastic wastes.

Microplastic and PTFE contamination of food from cookware

Microplastics are a prolific environmental contaminant that have been evidenced in human tissues. Human uptake of microplastic occurs via inhalation of airborne fibres and ingestion of microplastic-contaminated foods and beverages. Plastic and PTFE-coated cookware and food contact materials may release micro- and nanoplastics into food during food preparation. In this study, the extent to which non-plastic, new plastic and old plastic cookware releases microplastics into prepared food is investigated. Jelly is used as a food simulant, undergoing a series of processing steps including heating, cooling, mixing, slicing and storage to replicate food preparation steps undertaken in home kitchens. Using non-plastic cookware did not introduce microplastics to the food simulant. Conversely, using new and old plastic cookware resulted in significant increases in microplastic contamination. Microplastics comprised PTFE, polyethylene and polypropylene particulates and fibrous particles, ranging 13-318 μm. Assuming a meal was prepared daily per the prescribed methodology, new and old plastic cookware may be contributing 2409-4964 microplastics per annum into homecooked food. The health implications of ingesting microplastics remains unclear.

Non-negligible Toxicity to Fish in the Early Life Stages Triggered by Aqueous Leachate of Takeaway Plastic Containers

Ordering takeout is a growing social phenomenon and may raise public health concerns. However, the associated health risk of compounds leaching from plastic packaging is unknown due to the lack of chemical and toxicity data. In this study, 20 chemical candidates were tentatively identified in the environmentally relevant leachate from plastic containers through the nontargeted chemical analysis. Three main components with high responses and/or predicted toxicity were further verified and quantified, namely, 3,5-di-tert-butyl-4-hydroxycinnamic acid (BHC), 2,4-di-tert-butylphenol (2,4-DTBP), and 9-octadecenamide (oleamide). The toxicity to zebrafish larvae of BHC, a degradation product of a widely used antioxidant Irganox 1010, was quite similar to that of the whole plastic leachate. In the same manner, RNA-seq-based ingenuity analysis showed that the affected canonical pathways of zebrafish larvae were quite comparable between BHC and the whole plastic leachate, i.e., highly relevant to neurological disease, metabolic disease, and even behavioral disorder. Longer-term exposure (35 days) did not cause any effect on adult zebrafish but led to decreased hatching rate and obvious neurotoxicity in zebrafish offspring. Collectively, this study strongly suggests that plastic containers can leach out a suite of compounds causing non-negligible impacts on the early stages of fish via direct or parental exposure.

A systematic review of microplastics emissions in kitchens: Understanding the links with diseases in daily life

The intensification of microplastics (MPs) pollution has emerged as a formidable environmental challenge, with profound global implications. The pervasive presence of MPs across a multitude of environmental mediums, such as the atmosphere, soil, and oceans, extends to commonplace items, culminating in widespread human ingestion and accumulation via channels like food, water, and air. In the domestic realm, kitchens have become significant epicenters for MPs pollution. A plethora of kitchen utensils, encompassing coated non-stick pans, plastic cutting boards, and disposable utensils, are known to release substantial quantities of MPs particles in everyday use, which can then be ingested alongside food. This paper conducts a thorough examination of contemporary research addressing the release of MPs from kitchen utensils during usage and focuses on the health risks associated with MPs ingestion, as well as the myriad factors influencing the release of MPs in kitchen utensils. Leveraging the insights derived from this analysis, this paper proposes a series of strategic recommendations and measures targeted at mitigating the production of MPs in kitchen settings. These initiatives are designed not solely to diminish the release of MPs but also to enhance public awareness regarding this pressing environmental concern. By adopting more informed practices in kitchens, we can significantly contribute to the reduction of the environmental burden of MPs pollution, thus safeguarding both human health and the ecological system.

Single pulmonary nanopolystyrene exposure in late-stage pregnancy dysregulates maternal and fetal cardiovascular function

Large-scale production and waste of plastic materials have resulted in widespread environmental contamination by the breakdown product of bulk plastic materials to micro- and nanoplastics (MNPs). The small size of these particles enables their suspension in the air, making pulmonary exposure inevitable. Previous work has demonstrated that xenobiotic pulmonary exposure to nanoparticles during gestation leads to maternal vascular impairments, as well as cardiovascular dysfunction within the fetus. Few studies have assessed the toxicological consequences of maternal nanoplastic (NP) exposure; therefore, the objective of this study was to assess maternal and fetal health after a single maternal pulmonary exposure to polystyrene NP in late gestation. We hypothesized that this acute exposure would impair maternal and fetal cardiovascular function. Pregnant rats were exposed to nanopolystyrene on gestational day 19 via intratracheal instillation. 24 h later, maternal and fetal health outcomes were evaluated. Cardiovascular function was assessed in dams using vascular myography ex vivo and in fetuses in vivo function was measured via ultrasound. Both fetal and placental weight were reduced after maternal exposure to nanopolystyrene. Increased heart weight and vascular dysfunction in the aorta were evident in exposed dams. Maternal exposure led to vascular dysfunction in the radial artery of the uterus, a resistance vessel that controls blood flow to the fetoplacental compartment. Function of the fetal heart, fetal aorta, and umbilical artery after gestational exposure was dysregulated. Taken together, these data suggest that exposure to NPs negatively impacts maternal and fetal health, highlighting the concern of MNPs exposure on pregnancy and fetal development.

Micro and nano plastics release from a single absorbable suture into simulated body fluid

Synthetic polymers are widely used in medical devices and implants where biocompatibility and mechanical strength are key enablers of emerging technologies. One concern that has not been widely studied is the potential of their microplastics (MPs) release. Here we studied the levels of MP debris released following 8-week in vitro tests on three typical polyglycolic acid (PGA) based absorbable sutures (PGA 100, PGA 90 and PGA 75) and two nonabsorbable sutures (polypropylene-PP and polyamide-PA) in simulated body fluid. The MP release levels ranked from PGA 100 > > PGA 90 > PGA 75 > > PP ∼ PA. A typical PGA 100 suture released 0.63 ± 0.087 million micro (MPs > 1 µm) and 1.96 ± 0.04 million nano (NPs, 200-1000 nm) plastic particles per centimeter. In contrast, no MPs were released from the nonabsorbable sutures under the same conditions. PGA that was co-blended with 10-25% L-lactide or epsilon-caprolactone resulted in a two orders of magnitude lower level of MP release. These results underscore the need to assess the release of nano- and microplastics from medical polymers while applied in the human body and to evaluate possible risks to human health.

Advances in the Interaction between Food-Derived Nanoparticles and the Intestinal Barrier

The maintenance of the intestinal barrier is crucial for the overall balance of the gut and the organism. Dysfunction of the intestinal barrier is closely associated with intestinal diseases. In recent years, due to the increased presence of nanoparticles (NPs) in the human diet, there has been a growing concern regarding the safety and potential impact of these NPs on gastrointestinal health. The interactions between food-derived NPs and the intestinal barrier are numerous. This review provides an introduction to the structure and function of the intestinal barrier along with a comprehensive summary of the interactions between food NPs and the intestinal barrier. Additionally, we highlight the potential connection between the food NPs-induced dysfunction of the intestinal barrier and inflammatory bowel disease. Finally, we discuss the enhancement of food NPs on the repair of the intestinal barrier damage and the nutrients absorption. This review holds significant importance in furthering our understanding of the regulatory mechanisms of food-derived NPs on the intestinal barrier.

Migration testing of microplastics from selected water and food containers by Raman microscopy

The migration of microplastics (MPs) from plastic food packaging has received increasing attention. Despite numerous studies quantifying MPs released from food packaging, there is lack of systematic investigation on migration of MPs from food packages under US Food and Drug Administration (FDA)'s guidance for food contact substances. Herein, we aimed to determine the quantity and size distribution of MPs migrating from water and food plastic containers following US Food and Drug Administration (FDA)'s guidance using Raman microscopy. Six commonly used water and food containers made of polypropylene (PP), polyethylene terephthalate (PET), polystyrene (PS) were treated using distilled water and food stimulants (10% and 50% ethanol) under various conditions. A range of 23,702 to 490,330 particles per liter MPs with 77%- 92% smaller than 5 µm were detected, in which the PP food container exhibited the highest release of MPs when incubated with 50% ethanol at 130 °C for 15 min (equivalent to heating fatty food in a microwave). The temperature and food types were key attributes for elevating MP migration in general. Further comparison observed direct microwave (534,109 particles per liter) heating led to a significantly higher release of MPs compared to the FDA-suggested method (155,572 particles per liter). Part of MPs (12-63%) failed to be identified by Raman microscopy due to small particle size. Our estimation suggests that individuals might inhale up to 4511 MPs per kg per day. This research offers vital insights into MP migration from food and water containers, aiding in the development of relevant guidelines and facilitating MPs' risk assessment and management.

PLASTAMINATION: Outcomes on the Central Nervous System and Reproduction

BACKGROUND

Environmental exposures to non-biodegradable and biodegradable plastics are unavoidable. Microplastics (MPs) and nanoplastics (NPs) from the manufacturing of plastics (primary sources) and the degradation of plastic waste (secondary sources) can enter the food chain directly or indirectly and, passing biological barriers, could target both the brain and the gonads. Hence, the worldwide diffusion of environmental plastic contamination (PLASTAMINATION) in daily life may represent a possible and potentially serious risk to human health.

OBJECTIVE

This review provides an overview of the effects of non-biodegradable and the more recently introduced biodegradable MPs and NPs on the brain and brain-dependent reproductive functions, summarizing the molecular mechanisms and outcomes on nervous and reproductive organs. Data from in vitro, ex vivo, non-mammalian and mammalian animal models and epidemiological studies have been reviewed and discussed.

RESULTS

MPs and NPs from non-biodegradable plastics affect organs, tissues and cells from sensitive systems such as the brain and reproductive organs. Both MPs and NPs induce oxidative stress, chronic inflammation, energy metabolism disorders, mitochondrial dysfunction and cytotoxicity, which in turn are responsible for neuroinflammation, dysregulation of synaptic functions, metabolic dysbiosis, poor gamete quality, and neuronal and reproductive toxicity. In spite of this mechanistic knowledge gained from studies of non-biodegradable plastics, relatively little is known about the adverse effects or molecular mechanisms of MPs and NPs from biodegradable plastics.

CONCLUSION

The neurological and reproductive health risks of MPs/NPs exposure warrant serious consideration, and further studies on biodegradable plastics are recommended.

Nano- and Microplastics Migration from Plastic Food Packaging into Dairy Products: Impact on Nutrient Digestion, Absorption, and Metabolism

The ongoing use of plastic polymers to manufacture food packaging has raised concerns about the presence of nano- and microplastics (NMPs) in a variety of foods. This review provides the most recent data on NMPs' migration from plastic packaging into dairy products. Also discussed are the possible effects of NMPs on nutrient digestion, absorption, and metabolism. Different kinds of dairy products, including skimmed milk, whole liquid milk, powder milk, and infant formula milk, have been found to contain NMPs of various sizes, shapes, and concentrations. NMPs may interact with proteins, carbohydrates, and fats and have a detrimental impact on how well these nutrients are digested and absorbed by the body. The presence of NMPs in the gastrointestinal tract may impact how lipids, proteins, glucose, iron, and energy are metabolized, increasing the risk of developing various health conditions. In addition to NMPs, plastic oligomers released from food packaging material have been found to migrate to various foods and food simulants, though information regarding their effect on human health is limited. Viewpoints on potential directions for future studies on NMPs and their impact on nutrient digestion, absorption, and health are also presented in this review.

The unheeded inherent connections and overlap between microplastics and poly- and perfluoroalkyl substances: A comprehensive review

Microplastics (MPs) and poly- and perfluoroalkyl substances (PFASs) are receiving global attention due to their widespread presences and considerable level in the environment. Although the occurrence and fate of MPs and PFASs alone have been extensively studied, little was known about their unheeded connection and overlap between the two. Therefore, this review attempts to reveal it for the purpose of providing a new view from joint consideration of the two in the future studies. Initially, the critically examined data on the co-sources and existence of MPs and PFASs are summarized. Surprisingly, some products could be co-source of MPs and PFASs which are general in daily life while the distribution of the two is primary influenced by the human activity. Then, their interactions are reviewed based on the fact that PFASs can be sorbed onto MPs which are regarded as a vector of contaminations. The electrostatic interaction and hydrophobic contact are the predominant sorption mechanisms and could be influenced by environmental factors and properties of MPs and PFASs. The effects of MPs on the transport of PFASs in the environments, especially in aquatic environments are then discussed. Additionally, the current state of knowledge on the combined toxicity of MPs and PFASs are presented. Finally, the existing problems and future perspectives are outlined at the end of the review. This review provides an advanced understanding of the overlap, interaction and toxic effects of MPs and PFASs co-existing in the environment.

Migration of Dihydroxy Alkylamines and Their Possible Impurities from Packaging into Foods and Food Simulants: Analysis and Safety Evaluation

Alkyl diethanolamines are a group of compounds commonly used as antistatic agents in plastic food packaging materials. These additives and their possible impurities have the ability to transfer into the food; hence, the consumer may be exposed to these chemicals. Recently, scientific evidence of unknown adverse effects associated with these compounds was reported. N,N-bis(2-hydroxyethyl)alkyl (C8-C18) amines as well as other related compounds and their possible impurities were analyzed in different plastic packaging materials and coffee capsules using target and non-target LC-MS methods. N,N-bis(2-hydroxyethyl)alkyl amines, precisely, C12, C13, C14, C15, C16, C17 and C18, 2-(octadecylamino)ethanol and octadecylamine, among others, were identified in most of the analyzed samples. It should be emphasized that the latter compounds are not listed in the European Regulation 10/2011 and 2-(octadecylamino)ethanol was classified as high toxicity according to Cramer rules. Migration tests were carried out in foods and in the food simulants Tenax and 20% ethanol (v/v). The results showed that stearyldiethanolamine migrated into the tomato, salty biscuits, salad and Tenax. Lastly, as a crucial step in the risk assessment process, the dietary exposure to stearyldiethanolamine transferred from the food packaging into the food was determined. The estimated values ranged from 0.0005 to 0.0026 µg/kg bw/day.

Effects of microplastic exposure on the early developmental period and circadian rhythm of zebrafish (Danio rerio): A comparative study of polylactic acid and polyglycolic acid

Polyglycolic acid (PGA) is an emerging biodegradable plastic material. Together with polylactic acid (PLA), PGA is considered a suitable alternative to conventional plastics and has been widely used in biomedical and food packaging industries. However, degradable plastics continue to face the drawbacks of harsh degradation environment and long degradation time, and may harm the environment and the human body. Therefore, our study focused on assessing the effects of degradable microplastics PGA and PLA on the development and neurobehavior of zebrafish. The results showed that PGA and PLA had little effect on 3-10 hpf embryos. However, developmental stunting was observed in a100 mg/L PGA and PLA-exposed group at 24 hpf. In addition, PGA and PLA exposure decreased the survival and hatching rates, increased wakefulness, and reduced sleep in zebrafish. This indicates that PGA and PLA may affect the circadian behavior of zebrafish by affecting the brain-derived neurotrophic factor (BDNF). Therefore, our results suggest that PGA and PLA exposure induces developmental toxicity, reduces voluntary locomotion, induces of anxiety-like behaviors, and impairs sleep/wake behaviors in zebrafish larvae. This also suggests that the potentially toxic effects of degradable plastics cannot be ignored and that the biological effects of PGA require further research.

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.

Migration of microplastics from plastic packaging into foods and its potential threats on human health

Microplastics from food packaging material have risen in number and dispersion in the aquatic system, the terrestrial environment, and the atmosphere in recent decades. Microplastics are of particular concern due to their long-term durability in the environment, their great potential for releasing plastic monomers and additives/chemicals, and their vector-capacity for adsorbing or collecting other pollutants. Consumption of foods containing migrating monomers can lead to accumulation in the body and the build-up of monomers in the body can trigger cancer. The book chapter focuses the commercial plastic food packaging materials and describes their release mechanisms of microplastics from packaging into foods. To prevent the potential risk of microplastics migrated into food products, the factors influencing microplastic to the food products, e.g., high temperatures, ultraviolet and bacteria, have been discussed. Additionally, as many evidences shows that the microplastic components are toxic and carcinogenic, the potential threats and negative effects on human health have also been highlighted. Moreover, future trends is summarized to reduce the microplastic migration by enhancing public awareness as well as improving waste management.

Microplastics in polystyrene-made food containers from China: abundance, shape, size, and human intake

Polystyrene-made food containers (PMFCs) have been widely used as takeout containers in China. However, the pollution of microplastics (MPs) in PMFCs used in Chinese restaurants remains not well known. For the first time, this study analyzed MPs in PMFC samples (n = 354) collected from different restaurants in 28 Chinese cities. MPs were detected in all PMFC samples, with an abundance of 5-173 items/container. PMFC samples from Taiyuan (mean of 86 items/container) contained the highest mean abundance of MPs. A relatively lower abundance of MPs was found in PMFCs from Urumqi (mean of 19 items/container) and Fuzhou (18 items/container). Fiber was the predominant shape of MPs in most of the PMFC samples. The abundance of MPs in PMFCs was positively correlated with the proportion of fiber. The major polymer composition of MPs was polystyrene, accounting for a mean of 45-90% of total polymers for MPs in PMFCs from different cities. The abundance of MPs in PMFC samples was negatively correlated with the proportion of polystyrene. The mean estimated oral exposure of MPs for the general population in different Chinese cities was 0.24-1.4 items/kg bw/day. Such data is important for human MP exposure risk assessment and also for elucidating the sources of human exposure to MPs.

Analysis of microplastics released from plastic take-out food containers based on thermal properties and morphology study

Plastic take-out food containers may release microplastics (MPs) into food and pose a potential risk to food safety and human health. Here, after being subjected to hot water treatment, MPs released from three types of plastic food containers (polypropylene, PP; polyethylene, PE; expanded polystyrene, EPS) were identified by micro-Raman spectroscopy. The results showed that the size of released MPs ranged from 0.8-38 μm and over 96% MPs were smaller than 10 μm. Various MPs concentrations were found from the three types of containers, that is, 1.90 × 10⁴, 1.01 × 10⁵, and 2.82 × 10⁶ particles/L on average from PP, PE, and EPS, respectively. Moreover, based on thermal and morphology analysis, we discovered that both relaxations of the polymer chains in the rubbery state and defects caused by processing techniques might contribute to the release of MPs. Thus, such release can be reduced by increasing the thermal stability of the materials and mitigating the defects generated during production.

Release of millions of micro(nano)plastic fragments from photooxidation of disposable plastic boxes

The widespread use of disposable plastic boxes is exacerbating the dangers of microplastics (MPs); however, little is known about the fragmentation behavior of MPs during aging. In this study, the dynamic evolution on the release of micro(nano)plastics and photoaging properties of two disposable plastic boxes (polypropylene (PP) and polystyrene (PS)) were investigated under light irradiation and mechanical abrasion. Results showed that the weight of PP and PS was decreased by 53 % and 100 %, respectively after 60 d of ultraviolet irradiation (UV60). Moreover, a large number of fragmented particles were produced from the combined light irradiation and abrasion, with 0.142 ± 0.006 and 0.141 ± 0.013 million micro(nano)plastics/mL particles from PP and PS boxes, respectively, and the nanometer range (<100 nm) accounted for 70.8 % and 46.8 %. The correlation model of the average size or alteration time versus carbonyl index (CI) was developed, which indicated that the fragmentation behavior was mainly related to the photooxidation, though mechanical abrasion also played a certain enhancing role. Additionally, PS was susceptible to the fragmentation and photooxidation compared to PP possibly since the phenyl ring of PS was more vulnerable to UV attack than the methyl of PP. The findings of this study clarify the dynamic fragmentation process of micro(nano)plastics of disposable plastic boxes and provide useful information to access environmental fate of MPs more holistically.

Microplastics Derived from Food Packaging Waste-Their Origin and Health Risks

Plastics are commonly used for packaging in the food industry. The most popular thermoplastic materials that have found such applications are polyethylene (PE), polypropylene (PP), poly(ethylene terephthalate) (PET), and polystyrene (PS). Unfortunately, most plastic packaging is disposable. As a consequence, significant amounts of waste are generated, entering the environment, and undergoing degradation processes. They can occur under the influence of mechanical forces, temperature, light, chemical, and biological factors. These factors can present synergistic or antagonistic effects. As a result of their action, microplastics are formed, which can undergo further fragmentation and decomposition into small-molecule compounds. During the degradation process, various additives used at the plastics' processing stage can also be released. Both microplastics and additives can negatively affect human and animal health. Determination of the negative consequences of microplastics on the environment and health is not possible without knowing the course of degradation processes of packaging waste and their products. In this article, we present the sources of microplastics, the causes and places of their formation, the transport of such particles, the degradation of plastics most often used in the production of packaging for food storage, the factors affecting the said process, and its effects.

Microplastics in Widely Used Polypropylene-Made Food Containers

As a potential threat to human health, ingestion of microplastics (MPs) has become of concern. Limited studies have carefully characterized the occurrence of MPs in polypropylene-made takeout food containers (TOFCs), which have been widely used in China. In this study, TOFC samples (n = 210) were collected from seven Chinese cities (Hangzhou, Guangzhou, Shanghai, Xining, Chengdu, Qingdao, and Dalian) and analyzed for MPs. All the TOFC samples contained MPs, with an abundance of 3−43 items/TOFC. The TOFCs from Chengdu (25 items/TOFC) contained the highest mean abundance of MPs, which is significantly (p < 0.01) higher than that from Shanghai (8.7 items/TOFC). Fiber accounted for 66−87% of the total for the shape of the MPs in the TOFCs from the different Chinese cities. Most of the MPs in the TOFCs from the different cities had a size of 201−500 μm and accounted for a mean 34−42% of the total MPs in the TOFCs. The major color type of the MPs in the TOFCs was transparent, accounting for a mean 39 (Qingdao)−73% (Hangzhou) of the total MPs. Polymer compositions of the MPs in the TOFCs were consistently dominated by polypropylene, which represented a mean 56−73% of the total MPs. The estimated daily intake of MPs for the general Chinese population through using TOFCs was in the range of 0.042−0.14 items/kg bw/day. To our knowledge, this is the most comprehensive study investigating the occurrence of MPs in TOFCs from China, which contributes to a better understanding of the sources of human oral exposure to MPs.

Microplastics in take-out food: Are we over taking it?

Take-out food has become increasingly prevalent due to the fast pace of people's life. However, few study has been done on microplastics in take-out food. Contacting with disposable plastic containers, take-out food may be contaminated with microplastics. In the present study, abundance and characteristics of microplastics in total of 146 take-out food samples including solid food samples and beverage samples (bubble tea and coffee) were determined and identified. The mean abundance of microplastics in take-out food was 639 items kg^-1, with the highest value in rice and the lowest value in coffee. Fragments shape, transparent color and sizes ≤ 500 μm were the main characteristics of microplastics in those food, and polyethylene was the main polymer type. Our results indicated that microplastics in take-out food was influenced by food categories and cooking methods, as well as food packaging materials. Approximately 170-638 items of microplastics may be consumed by people who order take-out food 1-2 times weekly.

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.

Alcohol Pretreatment to Eliminate the Interference of Micro Additive Particles in the Identification of Microplastics Using Raman Spectroscopy

Raman spectroscopy is an indispensable tool in the analysis of microplastics smaller than 20 μm. However, due to its limitation, Raman spectroscopy may be incapable of effectively distinguishing microplastics from micro additive particles. To validate this hypothesis, we characterized and compared the Raman spectra of six typical slip additives with polyethylene and found that their hit quality index values (0.93-0.96) are much higher than the accepted threshold value (0.70) used to identify microplastics. To prevent this interference, a new protocol involving an alcohol treatment step was introduced to successfully eliminate additive particles and accurately identify microplastics. Tests using the new protocol showed that three typical plastic products (polyethylene pellets, polyethylene bottle caps, and polypropylene food containers) can simultaneously release microplastic-like additive particles and microplastics regardless of the plastic type, daily-use scenario, or service duration. Micro additive particles can also adsorb onto and modify the surfaces of microplastics in a manner that may potentially increase their health risks. This study not only reveals the hidden problem associated with the substantial interference of additive particles in microplastic detection but also provides a cost-effective method to eliminate this interference and a rigorous basis to quantify the risks associated with microplastic exposure.

Prediction of Collision Cross-Section Values for Extractables and Leachables from Plastic Products

The use of ion mobility separation (IMS) in conjunction with high-resolution mass spectrometry has proved to be a reliable and useful technique for the characterization of small molecules from plastic products. Collision cross-section (CCS) values derived from IMS can be used as a structural descriptor to aid compound identification. One limitation of the application of IMS to the identification of chemicals from plastics is the lack of published empirical CCS values. As such, machine learning techniques can provide an alternative approach by generating predicted CCS values. Herein, experimental CCS values for over a thousand chemicals associated with plastics were collected from the literature and used to develop an accurate CCS prediction model for extractables and leachables from plastic products. The effect of different molecular descriptors and machine learning algorithms on the model performance were assessed. A support vector machine (SVM) model, based on Chemistry Development Kit (CDK) descriptors, provided the most accurate prediction with 93.3% of CCS values for [M + H]⁺ adducts and 95.0% of CCS values for [M + Na]⁺ adducts in testing sets predicted with <5% error. Median relative errors for the CCS values of the [M + H]⁺ and [M + Na]⁺ adducts were 1.42 and 1.76%, respectively. Subsequently, CCS values for the compounds in the Chemicals associated with Plastic Packaging Database and the Food Contact Chemicals Database were predicted using the SVM model developed herein. These values were integrated in our structural elucidation workflow and applied to the identification of plastic-related chemicals in river water. False positives were reduced, and the identification confidence level was improved by the incorporation of predicted CCS values in the suspect screening workflow.

Diet preference of zebrafish (Danio rerio) for bio-based polylactic acid microplastics and induced intestinal damage and microbiota dysbiosis

The ingestion of petroleum-based microplastics (MPs) by aquatic animals and their toxicological effects are of wide concern. However, the ecological risks of bio-based MPs to aquatic animals remain largely unknown. In the present study, zebrafish (Danio rerio) were exposed to MPs of polylactic acid (PLA), the most widely used bio-based plastic, and polyethylene terephthalate (PET), a high-production volume petroleum-based plastic. PLA MPs were more actively ingested by fish than PET MPs. The abundance of PLA MPs in fish intestines was approximately 170 times greater than that of PET MPs after one day of exposure. The ingestion of PLA MPs caused gastrointestinal damage in zebrafish. In addition, the ingestion of PLA MPs induced specific changes in the diversity of intestinal microbiota and promoted species closely linked with energy metabolism, cellular processes, and fish diseases. This might have been related to the depolymerization of PLA in the digestive tract, which decreased the intestinal pH and changed the carbon source structure. Overall, bio-based MPs may have different ecological effects on aquatic animals than traditional petroleum-based MPs.

Assessing Chemical Migration from Plastic Food Packaging into Food Simulant by Gas and Liquid Chromatography with High-Resolution Mass Spectrometry

Some components of plastic food packaging can migrate into food, and whereas migration studies of known components are required and relatively straightforward, identification of nonintentionally added substances (NIAS; unknowns) is challenging yet imperative to better characterizing food safety. To this aim, migration was investigated across 24 unique plastic food packaging products including plastic wrap, storage bags, vacuum bags, and meat trays. Gas and liquid chromatography separation systems coupled with Orbitrap mass analyzers were used for comprehensive nontargeted screening of migrants. Tentative identifications of features were assigned by searching commercial databases (e.g., NIST, MZCloud, ChemSpider, Extractables and Leachables) and filtering results based on mass accuracy, retention time indices, and mass spectral patterns. Several migrants showed elevated levels in specific food packaging types, particularly meat trays and plastic wrap, and varying degrees of migration over the 10 days. Eleven putative migrants are listed as substances of potential concern or priority hazardous substances. Additionally, migration amounts of an Irgafos 168 degradation product determined by semiquantitation exceeded proposed theoretical maximum migration values.

Disposable plastic materials release microplastics and harmful substances in hot water

The boom in the takeaway industry has significantly increased the consumption of disposable plastic materials, which are very likely to release microplastic particles and cause secondary risks during daily use. The objective of this study was to probe whether heat treatment of disposable plastic materials in water, mimicking their use for hot food or drink, could result in the release of particles and harmful substances in the leachate. Our results showed that a hot water (100 °C) soaking released 1.07 ± 0.507, 1.44 ± 0.147, 2.24 ± 0.719 and 1.57 ± 0.599 million submicron and microparticles/mL from plastic packaging, cups, transparent boxes and expandable boxes, respectively after 60 min of agitation, and the submicron fraction was dominant. Based on Fourier transform infrared spectroscopy, heat treatment also altered the chemical composition of polyethylene packaging, but it had minor effects on polypropylene cups, transparent boxes and polystyrene expandable boxes. In addition, organic chemicals and heavy metals (mainly As, Cr and Pb), with maximum concentrations of 2.1 ± 0.85 mgC/L and 4.2 ± 0.32 ng/L, were detected in the leachate from plastic packaging, cups and expandable boxes, indicating the potential risk of these materials while holding hot food or drink. The findings suggest the potential ingestion risk of microplastics and harmful substances by human beings during the daily use of disposable plastic materials.

Systematic Identification of Bioactive Compositions in Leaves of Morus Cultivars Using UHPLC-ESI-QTOF-MS/MS and Comprehensive Screening of High-Quality Resources

Morus spp. leaves (MSLs) show various beneficial effects in the treatment of metabolic-related diseases, which have created a growing interest in MSL development as dietary supplements and functional foods. The illustration of chemical compositions and screening of high-quality MSL resources are therefore necessary for further application. This study developed a new UHPLC-ESI-QTOF-MS/MS strategy of in-source collision-induced dissociation (IS-CID) and target collision-cell CID (TCC-CID) to quickly capture analogues with consistent skeleton, and combined global natural product social molecular networking (GNPS) to efficiently annotate bioactive phytochemicals in MSLs. For the results, 49 bioactive ingredients, including quercetin-type flavonoids, kaempferol-type flavonoids, chlorogenic acid isomers, 1-deoxynojirimycin, γ-aminobutyric acid, amino acids, and unsaturated fatty acids, were systematically identified in MSLs for the first time. Quantification for the typical components was simultaneously carried out in MSLs of 90 Morus resources collected from different locations. Partial least squares discriminant analysis (PLS-DA) indicated that quercetin-3-O-(6″-O-malonyl)-glucoside, rutin, kaempferol-3-O-(6″-O-malonyl)-glucoside, kaempferol-3-O-rutinoside, and chlorogenic acid showed high variable importance in the project (VIP > 1) that were significant constituents for the differences between MSL species. Then, high-quality MSLs were comprehensively screened in multiple Morus cultivars based on the criteria importance through intercriteria correlation (CRITIC) method. This study presented an efficient strategy to annotate bioactive compounds, revealed the difference of bioactive components in MSLs, and provided important information for the high-value production of Morus cultivars in food and supplement fields.

The influence of drinking water constituents on the level of microplastic release from plastic kettles

Microplastic (MP) release from household plastic products has become a global concern due to the high recorded levels of microplastic and the direct risk of human exposure. However, the most widely used MP measurement protocol, which involves the use of deionized (DI) water, fails to account for the ions and particles present in real drinking water. In this paper, the influence of typical ions (Ca²⁺/HCO₃^-, Fe³⁺, Cu²⁺) and particles (Fe₂O₃ particles) on MP release was systematically investigated by conducting a 100-day study using plastic kettles. Surprisingly, after 40 days, all ions resulted in a greater than 89.0% reduction in MP release while Fe₂O₃ particles showed no significant effect compared to the DI water control. The MP reduction efficiency ranking is Fe³⁺ ≈ Cu²⁺ > Ca²⁺/HCO₃^- > > Fe₂O₃ particles ≈ DI water. Physical and chemical characterization using SEM-EDX, AFM, XPS and Raman spectroscopy confirmed Ca²⁺/HCO₃^-, Cu²⁺ and Fe³⁺ ions are transformed into passivating films of CaCO₃, CuO, and Fe₂O₃, respectively, which are barriers to MP release. In contrast, there was no film formed when the plastic was exposed to Fe₂O₃ particles. Studies also confirmed that films with different chemical compositions form naturally in kettles during real life due to the different ions present in local regional water supplies. All films identified in this study can substantially reduce the levels of MP release while withstanding the repeated adverse conditions associated with daily use. This study underscores the potential for regional variations in human MP exposure due to the substantial impact water constituents have on the formation of passivating film formation and the subsequent release of MPs.

Immunotoxicity responses to polystyrene nanoplastics and their related mechanisms in the liver of zebrafish (Danio rerio) larvae

Nanoplastics in aquatic environments may induce adverse immunotoxicity effects in fish. However, there is insufficient evidence on the visible immunotoxicity endpoints in the larval stages of fish. The liver plays an important role in systemic and local innate immunity in the fish. In this study, the hepatic inflammatory effects of polystyrene (PS) nanoplastic particles (NPs: 100 and 50 nm) and micron PS particles on transgenic zebrafish (Danio rerio) larvae were estimated using fluorescent-labeled neutrophils, macrophages, and liver-type inflammatory binding protein (fabp10a). Particles with smaller size induced higher aggregations of neutrophils and apoptosis of macrophages in the abdomen of the larvae, corresponding to greater hepatic inflammation in the larvae. NPs increased the expression of fabp10a in the larval livers in a dose- and size-dependent manner. PS particles of 50 nm at a concentration of 0.1 mg·L^-1 increased the expression of fabp10a in the larval liver by 21.90% (P < 0.05). The plausible mechanisms of these effects depend on their distribution and the generation of reactive oxygen species in the larvae. Metabonomic analysis revealed that the metabolic pathways of catabolic processes, amino acids, and purines were highly promoted by NPs, compared to micron PS particles. NPs also activate steroid hormone biosynthesis in zebrafish larvae, which may lead to the occurrence of immune-related diseases. For the first time, the liver was identified as the target organ for the immunotoxicity effects of NPs in the larval stage of fish.

Integrated sample-pretreatment strategy for separation and enrichment of microplastics and primary aromatic amines in the migration of teabag

In this work, an integrated sample-pretreatment strategy for the separation and enrichment of microplastics and primary aromatic amines from the migration of teabag was developed. The migration solution of teabag was passed through a homemade device. The microplastics were firstly captured by a silver membrane, and then the primary aromatic amines were enriched by a solid-phase extraction column. The microplastics migrated from teabag were detected by attenuated total reflection-Fourier transform infrared spectrometer and Raman spectroscopy. The data showed the character, the number of particles, area ratio, and morphology of microplastics migrated from the teabag. Subsequently, after the enrichment procedure, a sensitive analytical method for primary aromatic amines was established followed by ultra-high performance liquid chromatography-tandem mass spectrometry. The method showed wide linear ranges with R² greater than 0.9915, low limits of detection (2-18 ng/L), and low limits of quantification (8-50 ng/L). The developed method was adopted to analyze microplastics and primary aromatic amines migrated from nylon and polyethylene terephthalate teabag under different temperatures and times. The integrated sample-pretreatment strategy displayed promising potentials in the one-step preparation of the microplastics and hazardous molecules in the sample of environment and food security.