Wide occurrence of seven phthalate plasticizers and two typical microplastics in pig feed

Influence of selected dosages of plastic microparticles on the porcine fecal microbiome

Studies conducted so far have shown that nano- and microplastic may disturb the intestinal microenvironment by interacting with the intestinal epithelium and the gut microbiota. Depending on the research model used, the effect on the microbiome is different-an increase or decrease in selected taxa resulting in the development of dysbiosis. Dysbiosis may be associated with intestinal inflammation, development of mental disorders or diabetes. The aim of the study was to analyze the intestinal microbiome in 15 gilts divided into 3 research groups (n = 5; control group, receiving micropartices at a dose 0.1 g/day (LD) and 1 g/day (HD)). Feaces were collected before and after 28 days of exposure to PET microplastics. The analysis of the intestinal microbiome was performed using next-generation sequencing. Alpha and beta diversity indices were compared, showing, that repetition affected only the abundance indices in the control and LD groups, but not in the HD group. The relationships between the number of reads at the phylum, genus and species level and the microplastic dose were calculated using statistical methods (r-Pearson correlation, generalized regression model, analysis of variance). The statistical analysis revealed, that populations of Family XIII AD3011 group, Coprococcus, V9D2013 group, UCG-010 and Sphaerochaeta increased with increasing MP-PET dose. The above-mentioned taxa are mainly responsible for the production of short-chain fatty acids (SCFA). It may be assumed, that SCFA are one of the mechanisms involved in the response to oral exposure to MP-PET.

Environmental microplastic and phthalate esters co-contamination, interrelationships, co-toxicity and mechanisms. A review

Plastics have been pervasive in society for decades, causing extensive environmental contamination. The co-occurrence of microplastics (MPs) and phthalate esters (PAEs) in the environment has significant implications for the global population. This review focuses on the simultaneous presence of MPs and PAEs, exploring co-pollution, leaching, adsorption, correlation, and co-toxicity. Both MPs and PAEs are found in various environmental compartments, including water, sediments, aquatic organisms, pig feed, masks, gloves, and liquid waste from garbage infiltration. Factors such as time, temperature, UV light exposure, and the type of MPs can influence the leaching and adsorption of PAEs onto MPs. The correlation between MPs and PAEs allows for the use of PAEs as indicators for the presence of MPs. However, current constraints, like limited data availability and regional coverage, impede the feasibility of comprehensive tracking. Additionally, the combined effects of MPs and PAEs demonstrate synergistic toxicity, leading to adverse health effects such as reproductive toxicity, neurotoxicity, hepatotoxicity, nephrotoxicity, and other toxicities, primarily mediated by oxidative stress processes. Consequently, the findings provide valuable insights for future researchers and regulatory bodies, enabling the development of more effective strategies to address the simultaneous presence of microplastics and PAEs and mitigate their harmful impacts on human health.

A critical review of microplastic pollution in breeding industry: Sources, distribution, impacts, and characterization techniques, mitigation strategies and future research directions

Microplastic (MP) pollution has garnered significant attention due to its detrimental effects on ecosystems and human health. If MPs contaminate farmed animals, they are more likely to enter the human body through the food chain, thereby impacting human health. Exploring MPs in breeding industry can provide a theoretical basis for breeding industry to prevent MP pollution. However, there is currently a lack of comprehensive summaries and overviews of MPs research in the industry as a whole. The core focus of the review is to improve our understanding of MPs in the breeding industry and provide valuable references and support for the development of mitigation strategies and policies. The review found that there are more studies related to MP pollution in the breeding industry, but there is inadequate information on the prevention and control technology. This review proposes strategies for prevention and control and discusses future research directions.

Microplastics from face masks: Unraveling combined toxicity with environmental hazards and their impacts on food safety

Microplastics (MPs) refer to tiny plastic particles, typically smaller than 5 mm in size. Due to increased mask usage during COVID-19, improper disposal has led to masks entering the environment and releasing MPs into the surroundings. MPs can absorb environmental hazards and transfer them to humans and animals via the food chain, yet their impacts on food safety and human health are largely neglected. This review summarizes the release process of MPs from face masks, influencing factors, and impacts on food safety. Highlights are given to the prevalence of MPs and their combined toxicities with other environmental hazards. Control strategies are also explored. The release of MPs from face masks is affected by environmental factors like pH, UV light, temperature, ionic strength, and weathering. Due to the chemical active surface and large surface area, MPs can act as vectors for heavy metals, toxins, pesticides, antibiotics and antibiotic resistance genes, and foodborne pathogens through different mechanisms, such as electrostatic interaction, precipitation, and bioaccumulation. After being adsorbed by MPs, the toxicity of these environmental hazards, such as oxidative stress, cell apoptosis, and disruption of metabolic energy levels, can be magnified. However, there is a lack of comprehensive research on both the combined toxicities of MPs and environmental hazards, as well as their corresponding control strategies. Future research should prioritize understanding the interaction of MPs with other hazards in the food chain, their combined toxicity, and integrating MPs detection and degradation methods with other hazards.

Unraveling the characteristics of microplastics in agricultural soils upon long-term organic fertilizer application: A comprehensive study using diversity indices

Microplastics negatively impact soil health and productivity. Organic fertilizers constitute significant contributors of microplastics in agricultural soils. Nevertheless, comprehensive data on the diversity of microplastics in long-term fertilized soils remain unavailable. In this study, we assessed the presence of microplastics in soils subjected to application of three different organic fertilizers (pig manure, chicken manure, and sludge composts) over 12 years, and evaluated the potential ecological risks posed by microplastic accumulation. The average microplastic abundance in soil was 368.88 ± 207.97 (range: 90-910) items/kg. Microplastic abundance differed among fertilization treatments, with substantial increases of 16.67%, 71.67%, and 61.43% upon low to high application of the three treatments, respectively. Overall, the microplastics predominantly comprised fibers (70.94%) and fragments (25.25%), of which a substantial proportion constituted light-colored microplastics (transparent and white). The size of microplastics was mainly concentrated in the 1-2 mm range (39.96%), with rayon, polypropylene, polyester, and polyethylene being identified as the major types. The risk assessment indices of the three treatments were 229.38, 257.64, and 175.89, respectively, and were all classified as level 4 (high risk). The microplastic diversity integrated index and principal component analysis revealed that microplastics were uniformly distributed throughout the 0-20 cm soil depth consequent to tillage activity. Together, these findings provide a comprehensive assessment of microplastic pollution in long-term fertilized soils and serve as a scientific basis for reducing microplastic contamination in agricultural soils.

Macrogenomes reveal microbial-mediated microplastic degradation pathways in the porcine gut: a hope for solving the environmental challenges of microplastics

It is increasingly recognized that microplastics (MPs) are being transmitted through the food chain system, but little is known about the microorganisms involved in MP degradation, functional biodegradation genes, and metabolic pathways of degradation in the intestinal tract of foodborne animals. In this study, we explored the potential flora mainly involved in MP degradation in the intestinal tracts of Taoyuan, Duroc, and Xiangcun pigs by macrogenomics, screened relevant MP degradation genes, and identified key enzymes and their mechanisms. The pig colon was enriched with abundant MP degradation-related genes, and gut microorganisms were their main hosts. The fiber diet did not significantly affect the abundance of MP degradation-related genes but significantly reduced their diversity. We identified a total of 94 functional genes for MP degradation and classified them into 27 categories by substrate type, with polystyrene (PS), polyethylene terephthalate (PET), and di(2-ethylhexyl) phthalate (DEHP) were the most predominant degradation types. The MP degradation functional genes were widely distributed in a variety of bacteria, mainly in the phylum Firmicutes and Bacteroidetes. Based on the identified functional genes for MP degradation, we proposed a hypothetical degradation mechanism for the three major MP pollutants, namely, PS, PET, and DEHP, which mainly consist of oxidoreductase, hydrolase, transferase, ligase, laccase, and isomerase. The degradation process involves the breakdown of long polymer chains, the oxidation of short-chain oligomers, the conversion of catechols, and the achievement of complete mineralization. Our findings provide insights into the function of MP degradation genes and their host microorganisms in the porcine colon.

Oral Exposure to Microplastics Affects the Neurochemical Plasticity of Reactive Neurons in the Porcine Jejunum

Plastics are present in almost every aspect of our lives. Polyethylene terephthalate (PET) is commonly used in the food industry. Microparticles can contaminate food and drinks, posing a threat to consumers. The presented study aims to determine the effect of microparticles of PET on the population of neurons positive for selected neurotransmitters in the enteric nervous system of the jejunum and histological structure. An amount of 15 pigs were divided into three groups (control, receiving 0.1 g, and 1 g/day/animal orally). After 28 days, fragments of the jejunum were collected for immunofluorescence and histological examination. The obtained results show that histological changes (injury of the apical parts of the villi, accumulations of cellular debris and mucus, eosinophil infiltration, and hyperaemia) were more pronounced in pigs receiving a higher dose of microparticles. The effect on neuronal nitric oxide synthase-, and substance P-positive neurons, depends on the examined plexus and the dose of microparticles. An increase in the percentage of galanin-positive neurons and a decrease in cocaine and amphetamine-regulated transcript-, vesicular acetylcholine transporter-, and vasoactive intestinal peptide-positive neurons do not show such relationships. The present study shows that microparticles can potentially have neurotoxic and pro-inflammatory effects, but there is a need for further research to determine the mechanism of this process and possible further effects.

Phthalate Biomarkers Composition in Relation to Fatty Liver: Evidence from Epidemiologic and in vivo studies

Phthalates, classified as environmental endocrine disruptors, pose potential toxicity risks to human health. Metabolic dysfunction-associated fatty liver disease is one of the most widespread liver diseases globally. Compared to studies focusing on metabolic disorders in relation to pollutants exposure, the impact of individual factors such as fatty liver on the in vivo metabolism of pollutants is always overlooked. Therefore, this study measured concentrations and composition of phthalate monoesters (mPAEs) in human urine samples, particularly those from fatty liver patients. Furthermore, we induced fatty liver in male Wistar rats by formulating a high-fat diet for twelve weeks. After administering a single dose of DEHP at 500 mg/kg bw through gavage, we compared the levels of di-2-ethylhexyl phthalate (DEHP), its metabolites (mDEHPs) and three hepatic metabolic enzymes, namely cytochrome P450 enzymes (CYP450), UDP glucuronosyltransferase 1 (UGT1), and carboxylesterase 1 (CarE1), between the normal and fatty liver rat groups. Compared to healthy individuals (n = 75), fatty liver patients (n = 104) exhibited significantly lower urinary concentrations of ∑mPAEs (median: 106 vs. 166 ng/mL), but with a higher proportion of mono-2-ethylhexyl phthalate in ∑mDEHPs (25.7 % vs. 9.9 %) (p < 0.05). In the animal experiment, we found that fatty liver in rats prolonged the elimination half-life of DEHP (24.61 h vs. 18.89 h) and increased the contents of CYP450, CarE1, and UGT1, implying the common but differentiated metabolism of DEHP as excess lipid accumulation in liver cells. This study provides valuable information on how to distinguish populations in biomonitoring studies across a diverse population and in assigning exposure classifications of phthalates or similar chemicals in epidemiologic studies.

Influence of polyethylene terephthalate (PET) microplastic on selected active substances in the intramural neurons of the porcine duodenum

BACKGROUND

Currently, society and industry generate huge amounts of plastics worldwide. The ubiquity of microplastics is obvious, but its impact on the animal and human organism remains not fully understood. The digestive tract is one of the first barriers between pathogens and xenobiotics and a living organism. Its proper functioning is extremely important in order to maintain homeostasis. The aim of this study was to determine the effect of microplastic on enteric nervous system and histological structure of swine duodenum. The experiment was carried out on 15 sexually immature gilts, approximately 8 weeks old. The animals were randomly divided into 3 study groups (n = 5/group). The control group received empty gelatin capsules once a day for 28 days, the first research group received daily gelatin capsules with polyethylene terephthalate (PET) particles as a mixture of particles of various sizes (maximum particle size 300 µm) at a dose of 0.1 g/animal/day. The second study group received a dose ten times higher-1 g/animal/day.

RESULTS

A dose of 1 g/day/animal causes more changes in the enteric nervous system and in the histological structure of duodenum. Statistically significant differences in the expression of cocaine and amphetamine regulated transcript, galanin, neuronal nitric oxide synthase, substance P, vesicular acetylcholine transporter and vasoactive intestinal peptide between control and high dose group was noted. The histopathological changes were more frequently observed in the pigs receiving higher dose of PET.

CONCLUSION

Based on this study it may be assumed, that oral intake of microplastic might have potential negative influence on digestive tract, but it is dose-dependent.

Are microplastics in livestock and poultry manure an emerging threat to agricultural soil safety?

Microplastics (MPs) have attracted much attention in recent years, due to the difficulty of degradation and threats to ecological systems and humans. Based on the analysis of 1429 articles on MPs in soil, we found that we know little about the behavior and fate of manure-born MPs from the livestock and poultry production systems to agriculture soils. This review summarizes the analytical methods for sampling, separation, and identification and the occurrence of MPs in livestock and poultry manure, mainly based on 7 surveys related to manure-born MPs. Then, the sources, fate, and environmental risks of MPs in livestock and poultry manure are discussed. MPs, heavy metals, pathogens, antibiotic resistance genes, and persistent organic pollutants are common pollutants in livestock and poultry manure. Worse, manure-born MPs will become smaller, rougher, and more numerous and could easily form more toxic compound pollution after complicated processes of manure treatment, which seriously threatens agricultural soil safety. Finally, an outlook is offered for future research. We hope this article to attract attention to the risks of MPs in livestock and poultry manure and provide a reference for future research.