Microplastics In Organisms Research Articles

Potential use of gammarus (Pontogammarus maeoticus) and shrimp (Palaemon elegans) as biomonitors of microplastics pollution in coastal environments

Microplastics (MPs) pose a significant threat to marine ecosystems, necessitating robust biomonitoring to assess aquatic risks and inform effective policymaking. In this study we investigated MPs pollution in gammarus (Pontogammarus maeoticus), shrimp (Palaemon elegans), sediment and water samples of southern coast of the Caspian Sea to assess the potential use of these two crustaceans as biomonitors of MPs pollution, bioconcentration of MPs in organisms’ tissue and the pollution risks of MPs in environmental matrices. Samples were collected from 6 stations during June to August 2023. MPs were found in all compartments with an average of 100 ± 45.34 items/kg dry weight, 0.45 ± 0.06 items/L, 0.38 ± 0.21 items/individual or 0.58 ± 0.34 items/g wet weight (ww) and 0.26 ± 0.15 items/individual or 8.69 ± 7.88 items/g ww, for sediments, seawaters, P. elegans and P. maeoticus, respectively. MPs were prevailed by class 300−1000 μm in size, polyamide in polymer, fiber in shape and black in color. P. maeoticus and P. elegans did not meet the selection criteria as MPs biomonitors. However, bioconcentration factor (BCF) illustrated that both crustaceans can absorb and accumulate MPs from their surrounding water (BCF >1). Based on contamination factors (CF) values, sampling stations were polluted with MPs (1 ≤ CF < 6). The overall pollution load index (PLI) for sediment and seawater stations were 2.47 and 1.88, respectively, indicating minor contamination with MPs in the risk level I. Current research provides useful information on MPs pollution in crustaceans species and the risk level of MPs in environmental matrices that can be suitable for bioaccumulation hazard assessment and future monitoring programs.

In vivo visualization of environmentally relevant microplastics and evaluation of gut barrier damages in Artemia franciscana

Although irregularly-shaped label-free microplastics (MPs) are predominantly distributed in the environment, non-destructive analysis of environmentally relevant MPs in organisms is still challenging. The purpose of the study is to suggest in vivo visual evidence of the uptake and effect of environmentally relevant MPs in organism. Transparent irregularly-shaped high-density polyethylene was selected as an environmentally relevant model MP and exposed to brine shrimp (Artemia franciscana). As a result, we suggest the application of SEM/EDX and coherent anti-Stokes Raman scattering (CARS) microspectroscopy as complementary tools to secure in vivo visual evidence of irregularly-shaped unlabeled MPs in living organisms without chemical digestion for biodistribution observations. Biological transmission electron microscopy also provides how ingested MPs physically affects the digestive tract in the brine shrimp which is rarely reported. In terms of environmental implications, this study would advance ecotoxicological research on microplastic pollution by providing a cutting-edge tool for investigating the bioavailability and ecotoxicity of environmentally relevant MPs in ecosystems.

Bioaccumulation of polycyclic aromatic hydrocarbons and their human health risks depend on the characteristics of microplastics in marine organisms of Sanggou Bay, China

Microplastics pose a threat to marine environments through their physical presence and as vectors of chemical pollutants. However, the impact of microplastics on the accumulation and human health risk of chemical pollutants in marine organisms remains largely unknown. In this study, we investigated the microplastics and polycyclic aromatic hydrocarbons (PAHs) pollution in marine organisms from Sanggou Bay and analyzed their correlations. Results showed that microplastic and PAHs concentration ranged from 1.23 ± 0.23 to 5.77 ± 1.10 items/g, from 6.98 ± 0.45 to 15.07 ± 1.25 μg/kg, respectively. The microplastic abundance, particularly of fibers, transparent and color plastic debris, correlates strongly with PAH contents, indicating that microplastics increase the bioaccumulation of PAHs and microplastics with these characteristics have a significant vector effect on PAHs. Although consuming seafood from Sanggou Bay induce no carcinogenic risk from PAHs, the presence of microplastics in organisms can significantly increases incremental lifetime cancer risk of PAHs. Thus, microplastics can serve as transport vectors for PAHs with implications for the potential health risks to human through consumption. This study provides new insight into the risks of microplastics in marine environments.

ELM combined with differential Raman spectroscopy for the detection of microplastics in organisms

Aiming at the problems of low extraction efficiency, high false detection rate, weak Raman signal and serious interference by fluorescence signal in the detection of microplastics in marine organisms, this paper establishes a set of rapid detection methods for microplastics in organisms, including confocal Raman spectroscopy, fluorescence imaging, differential Raman spectroscopy, and rapid identification of microplastics based on the ELM modeling assistance. Firstly, to address the problem of low extraction efficiency of microplastics, we explored and optimized the digestion method of tissues, which effectively improved the digestion effect of fish tissues and excluded the influence of tissues on microplastics detection. Aiming at the problems of high misdetection rate and low pre-screening efficiency of microplastics, fluorescence imaging technology is adopted to realize the visualization and detection of microplastics, which effectively improves the detection efficiency and precision of microplastics. Based on the confocal microscopy Raman spectroscopy detection system built independently in the laboratory, using 784/785 nm as the excitation light, the differential Raman spectroscopy technique effectively excludes the interference of fluorescence signals in the Raman spectra, and improves the signal-to-noise ratio of the Raman spectra, and the recovery rate of the Raman characteristic peaks in the differential Raman spectroscopy reaches 100 % compared to the traditional baseline correction method, which is 33.3 % higher than that of the baseline correction method. Finally, a microplastic identification model is constructed based on ELM to assist in realizing the rapid and accurate identification of microplastics. The more complete detection method of microplastics in marine organisms proposed in this paper can realize the rapid and nondestructive, efficient and accurate detection of microplastics in fish, which can help to further promote the development of marine microplastics monitoring technology.

Evidence of internalized microplastics in mussel tissues detected by volumetric Raman imaging

Microplastics are a global ecological concern due to their potential risk to wildlife and human health. Animals ingest microplastics, which can enter the trophic chain and ultimately impact human well-being. The ingestion of microplastics can cause physical and chemical damage to the animals' digestive systems, affecting their health. To estimate the risk to ecosystems and human health, it is crucial to understand the accumulation and localization of ingested microplastics within the cells and tissues of living organisms. However, analyzing this issue is challenging due to the risk of sample contamination, given the ubiquity of microplastics. Here, an analytical approach is employed to confirm the internalization of microplastics in cryogenic cross-sections of mussel tissue. Using 3D Raman confocal microscopy in combination with chemometrics, microplastics measuring 1 μm in size were detected. The results were further validated using optical and fluorescence microscopy. The findings revealed evidence of microplastics being internalized in the digestive epithelial tissues of exposed mussels (Mytilus galloprovincialis), specifically within the digestive cells forming digestive alveoli. This study highlights the need to investigate the internalization of microplastics in organisms like mussels, as it helps us understand the potential risks they pose to aquatic biota and ultimately to human health. By employing advanced imaging techniques, challenges associated with sample contamination can be overcome and valuable insights into the impact of microplastics on marine ecosystems and human consumers are provided.

Biodegradation of Typical Plastics: From Microbial Diversity to Metabolic Mechanisms.

Plastic production has increased dramatically, leading to accumulated plastic waste in the ocean. Marine plastics can be broken down into microplastics (<5 mm) by sunlight, machinery, and pressure. The accumulation of microplastics in organisms and the release of plastic additives can adversely affect the health of marine organisms. Biodegradation is one way to address plastic pollution in an environmentally friendly manner. Marine microorganisms can be more adapted to fluctuating environmental conditions such as salinity, temperature, pH, and pressure compared with terrestrial microorganisms, providing new opportunities to address plastic pollution. Pseudomonadota (Proteobacteria), Bacteroidota (Bacteroidetes), Bacillota (Firmicutes), and Cyanobacteria were frequently found on plastic biofilms and may degrade plastics. Currently, diverse plastic-degrading bacteria are being isolated from marine environments such as offshore and deep oceanic waters, especially Pseudomonas spp. Bacillus spp. Alcanivoras spp. and Actinomycetes. Some marine fungi and algae have also been revealed as plastic degraders. In this review, we focused on the advances in plastic biodegradation by marine microorganisms and their enzymes (esterase, cutinase, laccase, etc.) involved in the process of biodegradation of polyethylene terephthalate (PET), polystyrene (PS), polyethylene (PE), polyvinyl chloride (PVC), and polypropylene (PP) and highlighted the need to study plastic biodegradation in the deep sea.

Distribution and characteristics of microplastics in 16 benthic organisms in Haizhou Bay, China: Influence of habitat, feeding habits and trophic level

Microplastics (MPs) are widely found in the ocean and cause a serious risk to marine organisms. However, fewer studies have been conducted on benthic organisms. This study conducted a case study on the pollution characteristics of MPs on 16 marine benthic organisms in Haizhou Bay, and analyzed the effects of habitat, trophic level, and feeding mode on the MPs pollution characters. The results showed that MPs were detected in all 16 organisms with an average abundance of 8.84 ± 9.14 items/individual, which is in the middle-high level in the international scale. Among the detected MPs, the main material was cellophane. This study showed that benthic organisms can be used as indicator organisms for MPs pollution. MPs in organisms can be affected by their habitat, trophic level, and feeding mode. Comprehensive analysis of MPs in benthic organisms will contribute to fully understand the characterization and source resolution of MPs pollution.

Diel Pattern of Microplastic Residues in Zebrafish.

As one of the emerging pollutants, microplastics (MPs) can be taken up by aquatic organisms through ingestion. However, little is known about the uptake pattern in organisms over time and the associated mechanisms of retention patterns. The present study aims to elucidate these patterns in fish, their relationship with light/dark conditions, and examine the uptake kinetic process of small-sized plastic pollutants, especially during the long-neglected dark period. Zebrafish were sampled every 2 h during the light and dark periods after exposure to an environmentally relevant concentration (100 items/L) of MPs. The results demonstrated that MP residues in zebrafish decreased during the dark period rather than increased over time. The MP retention rhythm and the swimming behavior of exposed zebrafish displayed a statistically significant light/dark variation. Moreover, a very strong and statistically significant positive correlation was found between the swimming speed of zebrafish and the number of MP residues in the gastrointestinal tracts of zebrafish. These results clearly demonstrate that fibrous MP residues in the fish have a discernible diel pattern. This work improves the understanding of the dynamic residual process of MPs in organisms and calls for further in-depth circadian toxicokinetic studies to better suit particle pollutants.

Tissue Clearing To Localize Microplastics via Three-Dimensional Imaging of Whole Organisms.

Understanding the biological impacts of plastic pollution requires an effective methodology to detect unlabeled microplastics in environmental samples. Detecting unlabeled microplastics in an organism generally requires a digestion protocol, which results in the loss of spatial information on the distribution of microplastic within the organism and could lead to the disappearance of the smaller plastics. Fluorescence microscopy allows visualization of ingested microplastics but many labeling strategies are nonspecific and label biomass, thus limiting our ability to distinguish internalized plastics. While prelabeled plastics can be used to avoid nonspecific labeling, this approach precludes the detection of environmental microplastics in organisms. Also, using prelabeled microplastics can affect the viability of the organism and impact plastic uptake. Thus, a method was developed that employs nonspecific labeling with a tissue-clearing technique. Briefly, unlabeled microplastics are stained with a fluorescent dye after ingestion by the organism. The tissue-clearing technique then removes tissue-bound dye while rendering the structurally intact organism transparent. The internalized plastics remain stained and can be visualized in the cleared tissue with fluorescence microscopy. The technique is demonstrated using polystyrene beads in living aquatic organismsTigriopus californicusandDaphnia magnaand by spiking a model vertebrate (Cephalochordata) with different microplastics.

Iodine-131 radiolabeled polyvinylchloride: A potential radiotracer for micro and nanoplastics bioaccumulation and biodistribution study in organisms

The microplastics amount in the environment is significantly increasing due to human activity, and the hazards are still being investigated. To evaluate the fate of microplastics in organisms, an accurate, fast, and sensitive method is required. Nuclear technology harnessing radiotracer is one of the most sensitive and accurate method for bioaccumulation, biodistribution and biokinetic study. Here, we developed a preparation method for radioiodinated polyvinyl chloride (PVC) as a potential radiotracer of microplastics. Iodine-131 (131I) as a potential radiotracer for microplastic was used in this experiment (activity of 98.05–221.63 MBq). The 131I-PVC was prepared using the Conant-Finkelstein reaction with a solvent combination of phosphate buffer (B), acetone (A), and tetrahydrofuran (T). Such preparation method resulted in spherical 131I-PVC with sizes ranging from 608.6 to 5457.0 nm. Our study showed that acetone is the most suitable solvent for the radioiodination process, resulting in a stable 131I-PVC for up to six days.

Pollution status of microplastics in the freshwater environment of China: a mini review

In the last few years, the pollution of microplastics in freshwater environments such as rivers, lakes, and reservoirs has aroused widespread concerns. In this review, rich and appropriate data on microplastics, in the freshwater ecosystem of China, was collected. Following this microplastics in surface waters, sediments, and biota, of the freshwater system, were thoroughly analyzed. The results show that microplastics are widespread in the freshwater environment of China. At the same time, the abundance of microplastics is positively correlated with both intensive human activities and urbanization. The risk index of microplastics is relatively high in the water of Yellow River (654 items/L), Yangtze River (9.20 × 105 items/km2), and Pearl River regions (7571 items/m3). The prevalent shapes of microplastics, in water and sediments, are fragments and fibers. Moreover, the particle size of microplastics is mainly less than 2 mm. In fact, PP and PE are found to be the main polymer types in the freshwater environment of China. Bivalves and freshwater fish are the main research objects of microplastics pollution in China. In parallel to that, the abundance of microplastics, in each aquatic organism, varied from a few to a dozen. Additionally, the characteristics of microplastics in organisms are mainly fibers smaller than 1 mm. Fundamentally, the key two sources of microplastics, in the freshwater environment of China, are wastewater discharge and surface runoff. It is noteworthy that microplastics, in a freshwater environment, does not only cause environmental pollution but harms aquatic organisms, too. Finally, microplastics can reach the human body, through the food chain, causing potential health issues.

Suspected microplastics in Atlantic horse mackerel fish (Trachurus trachurus) captured in Portugal

Microplastics have been found in fish, but most studies have focused on the digestive system without considering additional organs. Herein, the objective was to assess the presence of microplastics in internal organs (gills, guts, kidney, heart) of the Atlantic horse mackerel (Trachurus trachurus) captured of the coast of Portugal (Northeast Atlantic Ocean). Suspected microplastics were present in all organs, with particles of larger size (i.e., equivalent diameter) found in the gut and those of lower size in the heart and its luminal blood. Suspected microplastics of 1–10 μm were the most abundant (65.4%), more likely to translocate, owing to their minute size, but more difficult to properly characterize. These results highlight the need to expand the analytical work on organs and tissues for assessing microplastics in organisms, but also emphasize the actual need for developing analytical methods that allow for an accurate isolation, identification, and characterization of microplastics in biota.

Full size microplastics in crab and fish collected from the mangrove wetland of Beibu Gulf: Evidences from Raman Tweezers (1–20 μm) and spectroscopy (20–5000 μm)

Microplastic pollution in organisms is a growing environmental concern worldwide. Current methods to identify microplastics (MPs) are subject to the limitations of analytical techniques, and there is no full-scale method to measure MPs in organisms. In this study, Raman Tweezers and spectroscopy methods were combined and applied to identify MPs in organisms within the size range of 1–5000 μm. The abundance of small MPs (1–20 μm) was measured in crab (0.39–2.83 items/individual) and fish (0.35–3.22 items/individual). Most MPs were transparent in color and pellet shape. The proportion of small MPs (1–20 μm) was 35.77%, and analysis revealed the non-inclusion of this fraction will induce large deviations in the overall measurement. The large MPs (20–5000 μm) were identified in crab and fish with abundances ranging from 0.74–4.96 items/individual and 0.72–5.39 items/individual, respectively. Mainly fiber shape items were detected, the dominant particle size ranged from 20 to 100 μm, and most MPs were white. Polyethylene (PE) and polyethylene terephthalate (PET) were the main types of MPs polymers detected. Our study fills the gap to provide a new method to detect MPs in organisms below 20 μm, facilitating study of the migration and transformation of small MPs in the environment.

An effective method for evaluation of microplastic contaminant in gastropod from Taihu Lake, China.

Microplastics are ubiquitous in the environment. The isolation and characterization of microplastics can change, enabling science to elucidate the fate of microplastics in organisms. The main objective of the present study was to develop a rapid and effective method for the isolation, characterization, and quantification of microplastics from gastropod, and then evaluate the microplastic pollution in wild freshwater snails using the developed method. The whole tissue of gastropod Bellamya aeruginosa was spiked with microplastics derived from cosmetic products to optimize the tissue digestion and microplastic identification process. Optimum digestion of soft tissue was performed using a mixture of Tris-HCl, proteinase K, and KOH. Recovery of microplastics from the tissue digests, as determined by microscopy and infrared spectroscopy, was 89 ± 5%. The entire procedure could be completed within 30h. Application of the procedure to wild freshwater snail B. aeruginosa collected from Taihu Lake revealed that 90~100% of the sampled snails accumulated 1 to 4 types of microplastics including poly(vinyl acetate), polyethylene terephthalate, polystyrene, and polyamides. In summary, a quick method was developed for the isolation and identification of microplastics from gastropod tissues, and the application of the method revealed the presence of microplastics in snails inhabiting Taihu Lake, China.

Influence of Six Digestion Methods on the Determination of Polystyrene Microplastics in Organisms Using the Fluorescence Intensity

Microplastic pollution has become a global environmental problem and is a cause of great concern. To evaluate the biological effects of microplastics, microplastics in organisms need to be accurately quantified. The quantification of microplastics in organisms using the fluorescence intensity is common; the digestion of biological samples is an important pretreatment method. However, the microplastics may be destroyed by digestion, which affects the fluorescence intensity of the microplastics and results in large deviations between measured and true values. In this study, six commonly used digestive agents were studied:KOH, NaOH, H2O2, HNO3, HNO3:HCl, and HNO3:HClO4. The effect of different digestion methods on the fluorescence intensity and surface morphology of microplastics was studied and the most suitable protocol was selected. The results show that, among the six different digestion methods, KOH digestion (100 g·L-1, 60℃) has the least influence on the fluorescence intensity of the microplastics and does not affect their surface morphology. The other five digestion methods lead to different degrees of reduction of the fluorescence intensity of microplastics and damage the microplastics' surface (aggregation, bubbles, scratches, and depressions). In addition, the KOH digestion method was used to extract microplastics from biological samples. The recovery rate was ≥ 96.3%±0.5%, indicating that the KOH digestion method is suitable for fluorescent microplastics in biological samples.