Impact of microplastics and nanoplastics on liver health:Current understanding and future research directions

With continuous population and economic growth in the 21st century,plastic pollution is a major global issue.However,the health concern of microplastics/nanoplastics(MPs/NPs)decomposed from plastic wastes has drawn public attention only in the recent decade.This article summarizes recent works dedicated to understanding the impact of MPs/NPs on the liver-the largest digestive organ,which is one of the primary routes that MPs/NPs enter human bodies.The interrelated mechanisms including oxidative stress,hepatocyte energy re-distribution,cell death and autophagy,as well as immune responses and inflammation,were also featured.In addition,the disturbance of microbiome and gut-liver axis,and the association with clinical diseases such as metabolic dysfunction-associated fatty liver disease,steatohepatitis,liver fibrosis,and cirrhosis were briefly discussed.Finally,we discussed potential directions in regard to this trending topic,highlighted current challenges in research,and proposed possible solutions.

Characteristics and Influencing Factors of Microplastics in Snow in the Inner Mongolia Plateau, China

Microplastics(MPs;<5 mm)have become one of the most prominent global environmental pollution problems.MPs can spread to high altitudes through atmospheric transport and can be deposited by rainfall or snowfall,potentially threatening the structure and function of natural ecosystems.MPs in terrestrial and aquatic ecosystems alter the growth and functional characteristics of organisms.However,little attention has been given to the possible harm associated with MPs deposited in snow,particularly in the context of global climate warming.MPs collected from surface snow in the Inner Mongolia Plateau,China,were used for quantitative analysis and identification.The results showed that MPs were easily detected,and the related concentration was approximately(68±10)–(199±22)MPsL1 in snow samples.Fibers were the most common morphology,the polymer composition was largely varied,and the abundance and composition of MPs were linked to human activity to a great extent.High-throughput sequencing results showed that the composition and abundance of microorganisms also differed in snow samples from areas with different MP pollution characteristics,indicating a considerable difference in microbial functional diversity.MPs may have an interference effect on the individual growth and functional expression of microorganisms in snow.In addition,the results showed that functional living areas(e.g.,landfills and suburban areas)in cities play an important role in the properties of MPs.For instance,the highest abundance of MPs was found in thermal power plants,whereas the abundance of polymers per sample was significantly lower in the suburban area.The MP contaminants hidden in snow can alter microbial structure and function and are therefore a potential threat to ecosystem health.

Microplastics in sediment of the Three Gorges Reservoir:abundance and characteristics under different environmental conditions

Freshwater microplastic pollution is an urgent issue of global concern,and research on the distribution in reservoirs is lacking.We investigated the microplastic pollution levels in wet sediments collected from the Three Gorges Reservoir,the largest reservoir of China.Results show that microplastics were ubiquitous in the sediments of the Three Gorges Reservoir,and their abundance ranged from 59 to 276 pp/kg(plastic particles per kg,dry weight).Economic development and total population were important factors affecting the spatial heterogeneity of microplastic abundance,and the contribution of large cities along the reservoir to microplastic pollution should be paid with more attention.Fibrous microplastics were the most abundant type of microplastic particles in reservoir sediments,whereas polystyrene,polypropylene,and polyamide were the main types of polymers.The apparent spatial heterogeneity in morphology and color of microplastics is attributed to different anthropogenic or landbased pollution sources.Moreover,the accumulation of microplastics near the inlet of tributaries reflects the role of potential contributors of tributaries.More importantly,multiple bisphenols(BPs)and heavy metals detected at the microplastic surfaces indicate that microplastics can act as carriers of these pollutants in the environment in the same way as sediments did,which may alter the environmental fate and toxicity of these pollutants.Therefore,we conclude that the Three Gorges Reservoir had been contaminated with microplastics,which posed a stress risk for organisms who ingest them along with their associated pollutants(BPs,heavy metals).

The Uptake and Distribution Evidence of Nano-and Microplastics in vivo after a Single High Dose of Oral Exposure

Objective Tissue uptake and distribution of nano-/microplastics was studied at a single high dose by gavage in vivo.Methods Fluorescent microspheres(100 nm,3μm,and 10μm)were given once at a dose of 200 mg/(kg∙body weight).The fluorescence intensity(FI)in observed organs was measured using the IVIS Spectrum at 0.5,1,2,and 4 h after administration.Histopathology was performed to corroborate these findings.Results In the 100 nm group,the FI of the stomach and small intestine were highest at 0.5 h,and the FI of the large intestine,excrement,lung,kidney,liver,and skeletal muscles were highest at 4 h compared with the control group(P<0.05).In the 3μm group,the FI only increased in the lung at 2 h(P<0.05).In the 10μm group,the FI increased in the large intestine and excrement at 2 h,and in the kidney at 4 h(P<0.05).The presence of nano-/microplastics in tissues was further verified by histopathology.The peak time of nanoplastic absorption in blood was confirmed.Conclusion Nanoplastics translocated rapidly to observed organs/tissues through blood circulation;however,only small amounts of MPs could penetrate the organs.

Occurrence of microplastics in natural and farmland soil in the Qilian Mountains of the Northern Tibetan Plateau

Microplastics(MPs)become ubiquitous in soil and are an environmental and public health concern worldwide.However,the status of MPs in natural and farmland soils in remote areas remains poorly understood.In this study,we investigated the characteristics of MPs in natural and farmland soils along two transects in the Qilian Mountains of the northern Tibetan Plateau.The average abundance of MPs in natural and farmland soils was 29,778 and 56,123 items kg^(-1),respectively,with a detection size range of 10-1000μm.MPs in the size range of 10-100μm accounted for 84.1%of particles detected.Among the 21 polymers detected,polyethylene dominated in both farmland and natural soils.The shape of MPs was dominated by fragments(95.8%),followed by fibers(3.8%)and beads(0.4%).The abundance of MPs was positively correlated with increasing altitude in natural soils.There was no significant correlation between the abundance of MPs and soil physicochemical properties due to the narrow range of values of soil physicochemical properties.With the growing concern regarding MPs pollution,research on the status of MPs in high altitude and remote areas is critical to understanding their global cycle.

Microplastics and microbiota:Unraveling the hidden environmental challenge

This editorial explores the intricate relationship between microplastics(MPs)and gut microbiota,emphasizing the complexity and environmental health implications.The gut microbiota,a crucial component of gastrointestinal health,is examined in the context of potential microbial degradation of MPs.Furthermore,dysbiosis induced by MPs emerges as a consensus,disrupting the balance of gut microbiota and decreasing diversity.The mechanisms triggering dysbiosis,including physical interactions and chemical composition,are under investigation.Ongoing research addresses the consequences of MPs on immune function,nutrient metabolism,and overall host health.The bidirectional relationship between MPs and gut microbiota has significant implications for environmental and human health.Despite uncertainties,MPs negatively impact gut microbiota and health.Further research is essential to unravel the complex interactions and assess the long-term consequences of MPs on both environmental and human well-being.

Responses of soil enzyme and microbial community under co-loading of different microplastics and sulfamethoxazole

Polyamide/polyethylene(PA/PE)microplastics were injected into soil containing sulfamethoxazole(SMX)to investigate their combined effects on SMX removal,soil enzyme activity,and microbial communities.The results show that both PA and PE transiently increase SMX removal and inhibite the stimulation of microbial species diversity by SMX.The effect of PE is more significant.Meanwhile,PE combined with SMX increases the relative abundances of Actinobacteria and Pseudomonas,while PA combined with SMX decreases the relative abundances of Nocardioides and Streptomyces.In addition,PA/PE combined with SMX can increase dehydrogenase,urease,ammonia monooxygenase,and nitrate reductase activities in the soil while inhibiting the activity of laccase.Compared with PA combined with SMX,the activities of dehydrogenase,urease,ammonia monooxygenase,and laccase of PE combined with SMX increase by 9.82%,10.41%,8.07%,and 5.47%,while the activities of nitrate reductase and neutral phosphatase decrease by 1.47%and 6.78%.

Research Progress of Detection Methods for Microplastics

Microplastics are plastic particles or fibers with a diameter of less than 5 mm,and they widely exist in the environment and pose potential risks to the ecosystem and human health.Microplastics detection can provide basic data for formulating effective environmental protection strategies.In this paper,the physical,chemical and biological detection methods of microplastics are reviewed,and the advantages and disadvantages of different methods are analyzed.The problems and challenges encountered in microplastics detection are analyzed,and the future research is discussed.

Research Progress of Microplastics Pollution in Environment

Microplastics pollution has become one of the focuses of global environmental science research.Microplastics include micro plastic particles and nano-plastic particles,which come from the decomposition of plastic products,the release of microfibers and the industrial process of plastic particles.The distribution of microplastics in water,soil and atmosphere is summarized,and the widespread existence of microplastics in different environmental media is emphasized.This paper also summarizes the potential impact of microplastics on ecosystems and organisms,and pays attention to the transmission and accumulation of microplastics in the food chain,as well as its potential threat to human health.Finally,the paper discusses the methods and technologies of microplastics treatment and monitoring at present,and puts forward the direction of further research on microplastics pollution in order to formulate more effective management and mitigation strategies.

Advances in Research of Collection and Detection Methods of Microplastics in Environment

As a new type of environmental pollutants,microplastics have gradually attracted people's attention.A large number of plastics discharged into the environment by human beings are constantly aging and breaking,and finally become microplastics.Microplastics can adsorb pollutants in the environment,and their components have certain toxicity,which can cause different degrees of harm to organisms.Due to the structural characteristics of microplastic particles,such as small particle size,large specific surface area,and their distribution in different environmental media,it is very difficult to accurately detect microplastics.Reliable collection and detection methods are the key to the study of environmental behavior of microplastics.In this study,the collection and detection methods of microplastics in the environment were reviewed,and the development direction of microplastics detection technology in the future was prospected.This study has a certain reference value for the related research and the prevention and treatment of micro-plastic pollution.

Detection and Identification of Microplastics from Locally Sold Fishes in Borongan City, Samar Island, Philippines

Microplastics, a prevailing modern contaminant, were detected on fish caught in Brgy. Mayangdan and Brgy. Tabunan, Borongan City, Eastern Samar. Fish samples were collected from markets and barangays, with 1 representative species per species, irrespective of location. The digestive channel, including the gills, was utilized as an anatomy of concern in fishes as the digestive systems are used in the feeding process while gills are primarily exposed to the water around them. Results found a few microplastics, mostly micro fragments that are irregularly shaped and colored either red or transparent/white. This concludes the presence of microplastics in the area of the two barangays in Borongan City. Therefore, it is highly recommended that the presence of microplastics in the water and mangrove areas of the said barangay be assessed to lessen the contamination of water systems with different plastic garbage.

Microplastics Detection and Identification in the Waters along Coastal Areas of Borongan City

This study detects the presence of microplastics in the coastal areas of Borongan City, Eastern Samar, this specifically implies the microplastics present in the waters along coastal areas of Borongan City. Two (2) sampling areas were identified and selected for the presence of these microcontaminants using density separation, filtration and microscopic identification. Results reveal a total of 35 microplastics observed from the water samples collected, with this the microplastics from Baybay boulevard with an average of 0.79 microplastics per Liter, while the average microplastic contamination in Hilangagan beach resort was calculated at 0.43 microplastics per Liter. This sums up to an average of 0.49 microplastics per Liter for both sampling sites in Borongan City.

Microplastics and Wastewater Treatment Plants—A Review

The emission of microplastics into nature poses a threat to aquatic and terrestrial ecosystems. Their penetration of the food chain presents a danger to human health as well. Wastewater treatment plants can be seen as the last barrier between microplastics and the environment. This review focuses on the impact of waste treatment plants in retaining microplastics. Studies show that no wastewater treatment method leads to a complete retention of microplastics, and so wastewater treatment plants themselves are viewed as point sources for the discharge of microplastics into the aquatic environment. Problems associated with the utilization of microplastic loaded sewage sludge are also discussed in the review.

Application of confocal laser Raman spectroscopy on marine sediment microplastics

Marine sediment is the primary sink of microplastics and is an indicator of pollution levels.However,although there are well-developed detection methods,detection is rarely focused on lowmicrometer-sized particles,mainly due to technique limitations.In this study,a simplifi ed process omitting digestion procedures was developed to pretreat microplastics obtained from marine sediment and was coupled with micro-Raman spectroscopy to identify microplastics.Based on the overall analysis of the characteristic peak assignments,a Raman spectral reference library was constructed for 18 types of plastic.In addition,the eff ects of the measurement parameters were systematically described.Field research was then conducted to validate the developed process and investigate microplastic contamination in Huiquan Bay,Qingdao,China.This simplifi ed process could retain the original appearance of microparticles and accomplish the detection of<500μm-sized microplastics in environmental samples.Microplastics in the size range of 10-150μm accounted for 76%of all microplastics,and 56%of the total particles was particles smaller than 50μm.Polypropylene(42%)and polyethylene(20%)were predominant components of the particles.In particular,polypropylene particles smaller than 10μm were identifi ed in marine sediment.This work demonstrates that Raman spectroscopy is not only an eff ective tool for detecting environmental particles but also highly applicable for identifying particles extracted from marine sediment.

Eff ect of polystyrene microplastics and temperature on growth,intestinal histology and immune responses of brine shrimp Artemia franciscana

Microplastics pollution and seawater temperature rise have been the major environmental issues,threatening the survival and biodiversity of marine organisms.This study evaluated the combined effect of temperature and polystyrene microplastics(MP)on Artemia,a filter-feeding crustacean that is widely used for environmental toxicology studies.Brine shrimp Artemia franciscana were exposed to three MP concentrations(0,0.2,and 2.0 mg/L)and three temperatures(22,26,and 30℃)for 14 d.In general,higher MP concentration and temperature led to a decreased survival rate and growth.Two-way ANOVA analysis indicated that the survival rate of Artemia was significantly impacted by both MP concentration and temperature(P<0.05),but there was no significant interaction between two factors(P>0.05).Growth of Artemia was significantly impacted by temperature(P<0.05),and with a significant interaction between two factors(P<0.05).Furthermore,the enzymatic activity,intestinal histological analyses,and immune gene expression were determined for Artemia reared at 30℃ with three MP concentrations(0,0.2,and 2.0 mg/L).The results showed that 2.0-mg/L MP resulted in reduced Artemia intestinal microvilli and exfoliated epithelia cells,significantly increased acid phosphatase(ACP)activity(P<0.05)and immunerelated gene ADRA1 B and CREB3 expression,revealing that higher MP concentration could induce oxidative and immunological stress on Artemia at 30℃.Overall,our study suggests that MP and temperature have combined adverse effect on Artemia,especially at relatively high temperature and polystyrene MP concentration.These findings are important to understand the potential ecological risks posed by these two factors on the organisms in marine environment.

Distribution, characteristics, and research status of microplastics in the trunk stream and main lakes of the Yangtze River: A review

Microplastic pollution has become an environmental issue of great concern owing to the persistence of microplastics and their potential adverse effects on biota.The Yangtze River is the longest river in China and the third-longest river in the world,and the microplastics in this river will affect the health of a large population living along with it.To ensure the survival safety of people,it is essential to plan ahead and investigate in advance in order to understand the microplastic pollution in the river and work out countermeasures.This paper reviews the literature concerning the microplastic pollution in the Yangtze River basin and analyzes the abundance,shapes,colors,and composition of microplastics in the water bodies and sediments in the trunk stream and main lakes of the Yangtze River.The results are as follows.Compared to other river basins in China and abroad,the microplastics in the Yangtze River basin have a moderate abundance and high spatial heterogeneity.Owing to the barrier effect of the Three Gorges Dam on microplastics,the abundance of microplastics in the Three Gorges Reservoir is generally an order of magnitude higher than that in other sections of the river.Most microplastics in the water bodies and sediments are less than 1 mm in size and are transparent and colorful.In terms of shapes,they are dominated by fibers,followed by fragments and films.In terms of composition,the microplastics in the source region of the Yangtze River are mainly composed of nylon and polyethylene,while the microplastics in the surface water from the lower reaches of the Jinsha River to the Yangtze River estuary are dominated by polypropylene and polyethylene.The microplastics are primarily derived from the secondary microplastics in the environment,and relatively intensive human activities increase the abundance of microplastics.These results serve as bases for understanding and preventing microplastic pollution in the Yangtze River.

Evidence on Invasion of Blood,Adipose Tissues,Nervous System and Reproductive System of Mice After a Single Oral Exposure:Nanoplastics versus Microplastics

Objective This study was designed to provide the evidences on the toxicokinetics of microplastics(MPs)and nanoplastics(NPs)in the bodies of mammals.Methods 100 nm,3μm,and 10μm fluorescent polystyrene(PS)beads were administered to mice once by gavage at a dose of 200 mg/kg body weight.The levels and change of fluorescence intensity in samples of blood,subcutaneous fat,perirenal fat,peritesticular fat,cerebrum,cerebellum,testis,and epididymis were measured at 0.5,1,2,and 4 h after administration using an IVIS Spectrum small-animal imaging system.Histological examination,confocal laser scanning,and transmission electron microscope were performed to corroborate the findings.Results After confirming fluorescent dye leaching and impact of pH value,increased levels of fluorescence intensity in blood,all adipose tissues examined,cerebrum,cerebellum,and testis were measured in the 100 nm group,but not in the 3 and 10μm groups except in the cerebellum and testis at 4 h for the 3μm PS beads.The presence of PS beads was further corroborated.Conclusion After a single oral exposure,NPs are absorbed rapidly in the blood,accumulate in adipose tissues,and penetrate the blood-brain/testis barriers.As expected,the toxicokinetics of MPs is significantly size-dependent in mammals.

Abundance and characteristics of microplastics in shellfi sh from Jiaozhou Bay,China

As an emerging pollutant,the presence of microplastics in marine organisms has been concerned increasingly.Shellfi sh,which are both economically and ecologically important,are of particular concern.In this study,we investigated the microplastic pollution in wild and farmed oysters(Crassostrea gigas)and clams(Ruditapes philippinarum)in the Jiaozhou Bay,China,for the fi rst time.We found the microplastic pollution in shellfi sh in Jiaozhou Bay was at a moderate level.The abundance of microplastics in shellfi sh ranged from 0.16 to 12.09 items/g(wet weight,ww)or 1 to 9 items/ind.The average abundance of the ingested microplastics was 1.21 items/g(or 2.17 items/ind.)in all shellfi sh,1.51 items/g(or 2.00 items/ind.)in clams and 0.92 items/g(or 2.34 items/ind.)in oysters.The abundance of microplastics in clams was signifi cantly higher than that in oysters.Most microplastics(92.97%)were fi bers,followed by fragments.The predominant color of the microplastics was black(42.97%),followed by blue,transparent,and red.Cellophane and polyethylene terephthalate(PET)dominated the microplastic composition.According to shellfi sh consumption,it can be inferred that the average microplastic consumption through Chinese diet is 1.27×10^(3)items per capita per year.

Interactions of Microplastics and Methane Seepage in the Deep-Sea Environment

Microplastics(MPs)are important exempla of the Anthropocene and are exerting an increasing impact on Earth’s carbon cycle.The huge imbalance between the MPs floating on the marine surface and those that are estimated to have been introduced into the ocean necessitates a detailed assessment of marine MP sinks.Here,we demonstrate that cold seep sediments,which are characterized by methane fluid seepage and a chemosynthetic ecosystem,effectively capture and accommodate small-scale(<100μm)MPs,with 16 types of MPs being detected.The abundance of MPs in the surface of the sediment is higher in methane-seepage locations than in non-seepage areas.Methane seepage is beneficial to the accumulation,fragmentation,increased diversity,and aging of MPs.In turn,the rough surfaces of MPs contribute to the sequestration of the electron acceptor ferric oxide,which is associated with the anaerobic oxidation of methane(AOM).The efficiency of the AOM determines whether the seeping methane(which has a greenhouse effect 83 times greater than that of CO_(2)over a 20-year period)can enter the atmosphere,which is important to the global methane cycle,since the deep-sea environment is regarded as the largest methane reservoir associated with natural gas hydrates.

Advances in Research of Characteristics and Removal of Microplastics in Sewage Treatment Plants

Microplastic pollution has become a worldwide issue.The discharge of sewage treatment plants(STPs)or wastewater treatment plant(WWTPs)is an important way for microplastics to enter the environment.This study reviewed the sources and occurrence characteristics(type,size,color and components)of microplastics in domestic and foreign sewage plants.It elaborated the removal principles of microplastics by primary,secondary and tertiary treatments.In addition,the removal effects of various treatment units and different processes on microplastics were summarized.In the future,the removal mechanism of microplastics in sewage treatment plants should be discussed in more depth,so as to further improve the removal rate of microplastics by optimizing and transforming traditional sewage treatment processes.Therefore,it is necessary to develop new technologies/processes specifically for the removal of microplastics and promote them to practical applications.