Transport and release of chemicals from plastics to the environment and to wildlife

Microplastic accumulation dynamics in Han river headwaters: Sediment interactions and environmental implication

The prevalence of microplastic (MP) contamination has become a significant environmental concern due to its pervasive nature and persistent effects. While sediments are considered major repositories for MPs, information on their spatial distribution within these matrices is insufficient. This research examined both the horizontal and vertical presence of MPs in the sediments surrounding Lake Paldang in South Korea, alongside a comprehensive evaluation of the physicochemical characteristics of the samples obtained. The total content of MPs varied from 2.15 to 122.2 particles g-1. The average contents of MPs on surface sediments were 40.47, 34.14, 5.01, and 8.19 particles g-1 in north mainstream (NM), south mainstream (SM), tributary (TB), and Tributary catchment (TC) based on Sonae Island, Gyeongan stream, respectively. The most abundant MP types were polyethylene (PE), polytetrafluoroethylene (PTFE), and polypropylene (PP), accounting for more than 70% of the total MPs. The most abundant sizes of MPs were within 45-100 µm. At all sediment depths, polymers were distributed in the order PE, PP, and polyester in NM, SM, and TC, respectively, whereas PTFE mainly occurred in the surface layer. MPs distribution also exhibited seasonal variation as larger inflows and flow rates varied with season.

Insight into effect of polyethylene microplastic on nitrogen removal in moving bed biofilm reactor: Focusing on microbial community and species interactions

Microplastics (MPs) pollution has emerged as a global concern, and wastewater treatment plants (WWTPs) are one of the potential sources of MPs in the environment. However, the effect of polyethylene MPs (PE) on nitrogen (N) removal in moving bed biofilm reactor (MBBR) remains unclear. We hypothesized that PE would affect N removal in MBBR by influencing its microbial community. In this study, we investigated the impacts of different PE concentrations (100, 500, and 1000 μg/L) on N removal, enzyme activities, and microbial community in MBBR. Folin-phenol and anthrone colorimetric methods, oxidative stress and enzyme activity tests, and high-throughput sequencing combined with bioinformation analysis were used to decipher the potential mechanisms. The results demonstrated that 1000 μg/L PE had the greatest effect on NH4+-N and TN removal, with a decrease of 33.5 % and 35.2 %, and nitrifying and denitrifying enzyme activities were restrained by 29.5-39.6 % and 24.6-47.4 %. Polysaccharide and protein contents were enhanced by PE, except for 1000 μg/L PE, which decreased protein content by 65.4 mg/g VSS. The positive links of species interactions under 1000 μg/L PE exposure was 52.07 %, higher than under 500 μg/L (51.05 %) and 100 μg/L PE (50.35 %). Relative abundance of some metabolism pathways like carbohydrate metabolism and energy metabolism were restrained by 0.07-0.11 % and 0.27-0.4 %. Moreover, the total abundance of nitrification and denitrification genes both decreased under PE exposure. Overall, PE reduced N removal by affecting microbial community structure and species interactions, inhibiting some key metabolic pathways, and suppressing key enzyme activity and functional gene abundance. This paper provides new insights into assessing the risk of MPs to WWTPs, contributing to ensuring the health of aquatic ecosystems.

The effect of additives on the biodegradation of polyhydroxyalkanoate (PHA) in marine field trials

The persistence of conventional fossil fuel-derived plastics in marine ecosystems has raised significant environmental concerns. Biodegradable plastics are being explored as an alternative. This study investigates the biodegradation behaviour in two marine environments of melt-extruded sheets of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) bioplastic as well as blends of PHBV with a non-toxic plasticiser (triethyl citrate, TEC) and composites of PHBV with wood flour. Samples were submerged for up to 35 weeks in two subtropical marine conditions: on the sandy seabed in the sublittoral benthic zone and the sandy seabed of an open air mesocosm with pumped seawater. Rates of biodegradation, lag times and times to 95 % mass loss (T95) were determined through mass loss data and Gompertz modelling. Mechanisms of biodegradation were studied through changes in molecular weight, mechanical properties and surface features. Results reveal a rapid biodegradation rate for all PHBV samples, demonstrating a range of specific biodegradation rates relative to exposed surface area of 0.03 ± 0.01 to 0.09 ± 0.04 mg.d-1.cm-2. This rapid rate of biodegradation meant that the subtle variations in biodegradation mechanisms across different sample thicknesses and additive compositions had little effect on overall lifetimes, with the T95 for most samples being around 250-350 days, regardless of site, highlighting the robust biodegradability of PHBV in seawater. It was only the PHBV-wood flour composite that showed faster biodegradation, and that was only in the exposed ocean site. The mesocosm site was otherwise shown to be a good model for the open ocean, with very comparable biodegradation rates and changes in mechanical properties over time.

Combined exposure of polystyrene microplastics and benzo[a]pyrene in rat: Study of the oxidative stress effects in the liver

Microplastics (MPs) and benzo[a]pyrene (B[a]P) are prevalent environmental pollutants. Numerous studies have extensively reported their individual adverse effects on organisms. However, the combined effects and mechanisms of exposure in mammals remain unknown. Thus, this study aims to investigate the potential effects of oral administration of 0.5μm polystyrene (PS) MPs (1 mg/mL or 5 mg/mL), B[a]P (1 mg/mL or 5 mg/mL) and combined (1 mg/mL or 5 mg/mL) on 64 male SD rats by gavage method over 6-weeks. The results demonstrate that the liver histopathological examination showed that the liver lobules in the combined (5 mg/kg) group had blurred and loose boundaries, liver cord morphological disorders, and significant steatosis. The levels of AST, ALT, TC, and TG in the combined dose groups were significantly higher than those in the other groups, the combined (5 mg/kg) group had the lowest levels of antioxidant enzymes and the highest levels of oxidants. The expression of Nrf2 was lowest and the expression of P38, NF-κB, and TNF-α was highest in the combined (5 mg/kg) group. In conclusion, these findings indicate that the combination of PSMPs and B[a]P can cause the highest levels of oxidative stress and elicit markedly enhanced toxic effects, which cause severe liver damage.

Microplastics and PAHs mixed contamination: An in-depth review on the sources, co-occurrence, and fate in marine ecosystems

Microplastics (MPs) and polycyclic aromatic hydrocarbons (PAHs) are toxic contaminants that have been found in marine ecosystems. This review aims to explore the sources and mechanisms of PAHs and MPs mixed contamination in marine environments. Understanding the released sources of PAHs and MPs is crucial for proposing appropriate regulations on the release of these contaminants. Additionally, the mechanisms of co-occurrence and the role of MPs in distributing PAHs in marine ecosystems were investigated in detail. Moreover, the chemical affinity between PAHs and MPs was proposed, highlighting the potential mechanisms that lead to their persistence in marine ecosystems. Moreover, we delve into the various factors influencing the co-occurrence, chemical affinity, and distribution of mixed contaminants in marine ecosystems. These factors, including environmental characteristics, MPs properties, PAHs molecular weight and hydrophobicity, and microbial interactions, were critically examined. The co-contamination raises concerns about the potential synergistic effects on their degradation and toxicity. Interesting, few studies have reported the enhanced photodegradation and biodegradation of contaminants under mixed contamination compared to their individual remediation. However, currently, the remediation strategies reported for PAHs and MPs mixed contamination are scarce and limited. While there have been some initiatives to remove PAHs and MPs individually, there is a lack of research specifically targeting the removal of mixed contaminants. This deficiency highlights the need for further investigation and the development of effective remediation approaches for the efficient remediation of PAHs and MPs from marine ecosystems.

A meta-research analysis on the biological impact of plastic litter in the marine biota

Marine litter and more specifically plastic marine litter is nowadays considered a global issue with unprecedented impact and consequences to the entire marine ecosystem and biota. The current situation that has been created worldwide due to the abundance of plastic litter in the Earth's Seas has been characterized as alarming, necessitating the immediate action for an overall reduction of plastic waste, better collection and recycling schemes and beach-shoreline clean-ups. In this article we attempt to delve into the details of the magnitude of the impact that plastic litter have caused to marine biota via a meta-research analysis, by compiling, combining, analysing and presenting data from various relative works, using primarily scientific and, secondarily, grey literature. Apart from the threats that plastic marine litter pose to the marine ecosystem, they present potential threats to humans, as well, via food chain. Aside from understating the risks and uncertainties contained in the hereby collected and presenting information, this study can provide an evidence base for decision and policy makers into implementing the appropriate action plans for reducing and, in time, mitigating this immense problem.

Plastiome: Plastisphere-enriched mobile resistome in aquatic environments

Aquatic microplastics (MPs) act as reservoirs for microbial communities, fostering the formation of a mobile resistome encompassing diverse antibiotic (ARGs) and biocide/metal resistance genes (BMRGs), and mobile genetic elements (MGEs). This collective genetic repertoire, referred to as the "plastiome," can potentially perpetuate environmental antimicrobial resistance (AMR). Our study examining two Japanese rivers near Tokyo revealed that waterborne MPs are primarily composed of polyethylene and polypropylene fibers and sheets of diverse origin. Clinically important genera like Exiguobacterium and Eubacterium were notably enriched on MPs. Metagenomic analysis uncovered a 3.46-fold higher enrichment of ARGs on MPs than those in water, with multidrug resistance genes (MDRGs) and BMRGs prevailing, particularly within MPs. Specific ARG and BMRG subtypes linked to resistance to vancomycin, beta-lactams, biocides, arsenic, and mercury showed selective enrichment on MPs. Network analysis revealed intense associations between host genera with ARGs, BMRGs, and MGEs on MPs, emphasizing their role in coselection. In contrast, river water exhibited weaker associations. This study underscores the complex interactions shaping the mobile plastiome in aquatic environments and emphasizes the global imperative for research to comprehend and effectively control AMR within the One Health framework.

Conversion of char from pyrolysis of plastic wastes into alternative activated carbons for heavy metal removal

The valorization of post-consumer mixed plastics in pyrolysis processes represents an abundant reservoir of carbon that can be effectively converted into useful chars. This process not only holds appeal in terms of improving plastic waste concerns but also contributes to the reduction of greenhouse gas emissions, thus aligning with the principles of a circular economy paradigm. In this study, the char produced from the pyrolysis of post-consumer mixed plastic waste has been activated with Na2CO3, KOH, NaOH, and K2CO3 to improve the textural, structural, and composition characteristics, leading to improved adsorption capability. These characteristics were studied by N2 adsorption-desorption isotherms, scanning electron microscopy, elemental and immediate analysis, and X-ray photoelectron spectroscopy. The developed surface area (SBET) was 573, 939, 704 and 592 m2 g-1 for Na2CO3, KOH, NaOH and K2CO3 activated carbons, respectively. These activated chars (ACs) were tested for the adsorption of heavy metals in both synthetic waters containing Pb, Cd, and Cu and industrial wastewater collected at an agrochemical production plant. Na2CO3-AC was the best performing material. The metal uptake in synthetic waters using a batch set-up was 40, 13 and 12 mg g-1 for Pb, Cd and Cu. Experiments in a column set-up using Na2CO3-AC resulted in a saturation time of 290, 16, and 80 min for Pb, Cd, and Cu synthetic waters, respectively, and metal uptakes of 26.8, 4.1, and 7.9 mg g-1, respectively. The agrochemical effluents, containing mainly Cr, Cu, Mn, and Zn were tested in a plug-flow column. The metal uptake notably decreased compared to synthetic water due to a competition effect for active sites.

Influence of trophic overlaps and trophic niche amplitude on microplastic intake of fish species in shallow areas of a neotropical coastal lagoon

Plastic pollution is a global challenge that affects all marine ecosystems, and reflects all types of uses and activities of human society in these environments. In marine ecosystems, microplastics and mesoplastics interact with invertebrates and become available to higher predators, such as fish, which can ingest these contaminants. This study aimed to analyze how ecological food interactions (diet overlap and trophic niche amplitude) among fish species contribute to the ingestion of plastic particles. The gastrointestinal contents of six fish species (Atherinella brasiliensis, Eucinostomus melanopterus, Eucinostomus argenteus, Genidens genidens, Coptodon rendalli, and Geophagus brasiliensis) were analyzed to identify prey items and plastic ingestion. Based on the ontogenetic classification, A. brasiliensis, E. melanopterus, and G. genidens were divided into juveniles and adults, and the six fish species analyzed were divided into nine predator groups. Most of the plastics ingested by the fish species were blue microplastic (MP) fibers (< 0.05 mm) classified as polyester terephthalate, polyethylene, and polybutadiene. Considering all the analyzed predators, the average number and weight of plastics ingested per individual were 2.01 and 0.0005 g, respectively. We observed that predators with a high trophic overlap could present a relationship with the intake of MP fibers owing to predation on the same resources. In addition, we observed the general pattern that when a species expands its trophic diversity and niche, it can become more susceptible to plastic ingestion. For example, the species with the highest Levin niche amplitude, E. argenteus juveniles, had the highest mean number (2.9) of ingested MP fibers. Understanding the feeding ecology and interactions among species, considering how each predator uses habitats and food resources, can provide a better understanding of how plastic particle contamination occurs and which habitats are contaminated with these polluting substances.

Plastic additives in the ocean: Use of a comprehensive dataset for meta-analysis and method development

In excess of 13,000 chemicals are added to plastics ('additives') to improve performance, durability, and production of plastic products. They are categorized into numerous chemical classes including flame retardants, light stabilizers, antioxidants, and plasticizers. While research on plastic additives in the marine environment has increased over the past decade, there is a lack of methodological standardization. To direct future measurement of plastic additives, we compiled a first-of-its-kind dataset of literature assessing plastic additives in marine environments, delineated by sample type (plastic debris, seawater, sediment, biota). Using this dataset, we performed a meta-analysis to summarize the state of the science. Currently, our dataset includes 217 publications published between 1978 and May 2023. The majority of publications analyzed plastic additives in biota collected from Europe and Asia. Analyses concentrated on plasticizers, brominated flame retardants, and bisphenols. Common sample preparation techniques included Solvent - Agitation extraction for plastic, sediment, and biota samples, and Solid Phase Extraction for seawater samples with dichloromethane and solvent mixtures including dichloromethane as the organic extraction solvent. Finally, most analyses were performed utilizing gas chromatography/mass spectrometry. There are a variety of data gaps illuminated by this meta-analysis, most notably the small number of compounds that have been targeted for detection compared to the large number of additives used in plastic production. The provided dataset facilitates future investigation of trends in plastic additive concentration data in the marine environment (allowing for comparison to toxicity thresholds) and acts as a starting point for optimizing and harmonizing plastic additive analytical methods.

Nanoplastics Detected in Commercial Sea Salt

People of all ages consume salt every day, but is it really just salt? Plastic nanoparticles [nanoplastics (NPs)] pose an increasing environmental threat and have begun to contaminate everyday salt in consumer goods. Herein, we developed a combined surface enhanced Raman scattering (SERS) and stimulated Raman scattering (SRS) approach that can realize the filtration, enrichment, and detection of NPs in commercial salt. The Au-loaded (50 nm) anodic alumina oxide substrate was used as the SERS substrate to explore the potential types of NP contaminants in salts. SRS was used to conduct imaging and quantify the presence of the NPs. SRS detection was successfully established through standard plastics, and NPs were identified through the match of the hydrocarbon group of the nanoparticles. Simultaneously, the NPs were quantified based on the high spatial resolution and rapid imaging of the SRS imaging platform. NPs in sea salts produced in Asia, Australasia, Europe, and the Atlantic were studied. We estimate that, depending on the location, an average person could be ingesting as many as 6 million NPs per year through the consumption of sea salt alone. The potential health hazards associated with NP ingestion should not be underestimated.

Snow dumping station - A considerable source of tyre wear, microplastics, and heavy metal pollution

Snow dumping stations can be a hotspots for pollutants to water resources. However, little is known about the amount of microplastics including tyre wear particles transported this way. This study investigated microplastics and metals in snow from four snow dumping stations in Riga, Latvia, a remote site (Gauja National Park), and a roof top in Riga. Microplastics other than tyre wear particles were identified with Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) (>500 µm) and focal plane array based micro-Fourier Transform Infrared (FPA-µFTIR) imaging (10-500 µm), tyre wear particles by Pyrolysis Gas Chromatography-Mass Spectroscopy (Py-GC-MS), and total metals by Inductively Coupled Plasma with Optical Emission Spectroscopy (ICP-OES). Microplastics detected by FTIR were quantified by particle counts and their mass estimated, while tyre wear particles were quantified by mass. The concentrations varied substantially, with the highest levels in the urban areas. Microplastic concentrations measured by FTIR ranged between 26 and 2549 counts L-1 of melted snow with a corresponding estimated mass of 19-573 µg/L. Tyre wear particles were not detected at the two reference sites, while other sites held 44-3026 µg/L. Metal concentrations varied several orders of magnitude with for example sodium in the range 0.45-819.54 mg/L and cadmium in the range 0.05-0.94 µg/L. Correlating microplastic measured by FTIR to metal content showed a weak to moderate correlation. Tyre wear particles, however, correlated strongly to many of the metals. The study showed that snow can hold considerable amounts of these pollutants, which upon melting and release of the meltwater to the aquatic environment could impact receiving waters.

Screening of plant growth-promoting rhizobacteria helps alleviate the joint toxicity of PVC+Cd pollution in sorghum plants

Combined microplastic and heavy metal pollution (CM-HP) has become a popular research topic due to the ability of these pollutants to have complex interactions. Plant growth-promoting rhizobacteria (PGPR) are widely used to alleviate stress from heavy metal pollution in plants. However, the effects and mechanisms by which these bacteria interact under CM-HP have not been extensively studied. In this study, we isolated and screened PGPR from CM-HP soils and analyzed the effects of these PGPR on sorghum growth and Cd accumulation under combined PVC+Cd pollution through pot experiments. The results showed that the length and biomass of sorghum plants grown in PVC+Cd contaminated soil were significantly lower than those grown in soils contaminated with Cd alone, revealing an enhancement in toxicity when the two contaminants were mixed. Seven isolated and screened PGPR strains effectively alleviated stress due to PVC+Cd contamination, which resulted in a significant enhancement in sorghum biomass. PGPR mitigated the decrease in soil available potassium, available phosphorus and alkali-hydrolyzable nitrogen content caused by combined PVC+Cd pollution and increased the contents of these soil nutrients. Soil treatment with combined PVC+Cd pollution and PGPR inoculation can affect rhizosphere bacterial communities and change the composition of dominant populations, such as Proteobacteria, Firmicutes, and Actinobacteria. PICRUSt2 functional profile prediction revealed that combined PVC+Cd pollution and PGPR inoculation affected nitrogen fixation, nitrification, denitrification, organic phosphorus mineralization, inorganic phosphorus solubilization and the composition and abundance of genes related the N and P cycles. The Mantel test showed that functional strain abundance, the diversity index and N and P cycling-related genes were affected by test strain inoculation and were significant factors affecting sorghum growth, Cd content and accumulation. This study revealed that soil inoculation with isolated and screened PGPR can affect the soil inorganic nutrient content and bacterial community composition, thereby alleviating the stress caused by CM-HP and providing a theoretical basis and data support for the remediation of CM-HP.

Polymer chain extenders induce significant toxicity through DAF-16 and SKN-1 pathways in Caenorhabditis elegans: A comparative analysis

Polymer chain extenders, commonly used in plastic production, have garnered increasing attention due to their potential environmental impacts. However, a comprehensive understanding of their ecological risks remains largely unknown. In this study, we employed the model organism Caenorhabditis elegans to investigate toxicological profiles of ten commonly-used chain extenders. Exposure to environmentally relevant concentrations of these chain extenders (ranging from 0.1 µg L-1 to 10 mg L-1) caused significant variations in toxicity. Lethality assays demonstrated the LC50 values ranged from 92.42 µg L-1 to 1553.65 mg L-1, indicating marked differences in acute toxicity. Sublethal exposures could inhibit nematodes' growth, shorten lifespan, and induce locomotor deficits, neuronal damage, and reproductive toxicity. Molecular analyses further elucidated the involvement of the DAF-16 and SKN-1 signaling pathways, as evidenced by upregulated expression of genes including ctl-1,2,3, sod-3, gcs-1, and gst-4. It implicates these pathways in mediating oxidative stress and toxicities induced by chain extenders. Particularly, hexamethylene diisocyanate and diallyl maleate exhibited markedly high toxicity among the chain extenders, as revealed through a comparative analysis of multiple endpoints. These findings demonstrate the potential ecotoxicological risks of polymer chain extenders, and suggest the need for more rigorous environmental safety assessments.

Colonization characteristics and surface effects of microplastic biofilms: Implications for environmental behavior of typical pollutants

This paper summarizes the colonization dynamics of biofilms on microplastics (MPs) surfaces in aquatic environments, encompassing bacterial characteristics, environmental factors affecting biofilm formation, and matrix types and characteristics. The interaction between biofilm and MPs was also discussed. Through summarizing recent literatures, it was found that MPs surfaces offer numerous benefits to microorganisms, including nutrient enrichment and enhanced resistance to environmental stress. Biofilm colonization changes the surface physical and chemical properties as well as the transport behavior of MPs. At the same time, biofilms also play an important role in the fragmentation and degradation of MPs. In addition, we also investigated the coexistence level, adsorption mechanism, enrichment, and transformation of MPs by environmental pollutants mediated by biofilms. Moreover, an interesting aspect about the colonization of biofilms was discussed. Biofilm colonization not only had a great effect on the accumulation of heavy metals by MPs, but also affects the interaction between particles and environmental pollutants, thereby changing their toxic effects and increasing the difficulty of MPs treatment. Consequently, further attention and research are warranted to delve into the internal mechanisms, environmental risks, and the control of the coexistence of MPs and biofilms.

Do weathered microplastics impact the planktonic community? A mesocosm approach in the Baltic Sea

Microplastics (MPs) are ubiquitous pollutants of increasing concern in aquatic systems. However, little is still known about the impacts of weathered MPs on plankton at the community level after long-term exposure. In this study, we investigated the effects of weathered MPs on the structure and dynamics of a Baltic Sea planktonic community during ca. 5 weeks of exposure using a mesocosm approach (2 m3) mimicking natural conditions. MPs were obtained from micronized commercial materials of polyvinyl chloride, polypropylene, polystyrene, and polyamide (nylon) previously weathered by thermal ageing and sunlight exposure. The planktonic community was exposed to 2 μg L-1 and 2 mg L-1 of MPs corresponding to measured particle concentrations (10-120 μm) of 680 MPs L-1 and 680 MPs mL-1, respectively. The abundance and composition of all size classes and groups of plankton and chlorophyll concentrations were periodically analyzed throughout the experiment. The population dynamics of the studied groups showed some variations between treatments, with negative and positive effects of MPs exhibited depending on the group and exposure time. The abundance of heterotrophic bacteria, pico- and nanophytoplankton, cryptophytes, and ciliates was lower in the treatment with the higher MP concentration than in the control at the last weeks of the exposure. The chlorophyll concentration and the abundances of heterotrophic nanoflagellates, Astromoeba, dinoflagellate, diatom, and metazooplankton were not negatively affected by the exposure to MPs and, in some cases, some groups showed even higher abundances in the MP treatments. Despite these tendencies, statistical analyses indicate that in most cases there were no statistically significant differences between treatments over the exposure period, even at very high exposure concentrations. Our results show that weathered MPs of the studied conventional plastic materials have minimal or negligible impact on planktonic communities after long-term exposure to environmentally relevant concentrations.

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.

Landfill leachates as a significant source for emerging pollutants of phthalic acid esters: Identification, occurrence, characteristics, fate, and transport

Phthalic acid esters (PAEs) are byproducts released from various sources, including microplastics, cosmetics, personal care products, pharmaceuticals, waxes, inks, detergents, and insecticides. This review article provides an overview of the literature on PAEs in landfill leachates, exploring their identification, occurrence, characteristics, fate, and transport in landfills across different countries. The study emphasizes the influence of these substances on the environment, especially on water and soil. Various analytical techniques, such as GC-MS, GC-FID, and HPLC, are commonly employed to quantify concentrations of PAEs. Studies show significant variations in levels of PAEs among different countries, with the highest concentration observed in landfill leachates in Brazil, followed by Iran. Among the different types of PAE, the survey highlights DEHP as the most concentrated PAE in the leachate, with a concentration of 89.6 μg/L. The review also discusses the levels of other types of PAEs. The data shows that DBP has the highest concentration at 6.8 mg/kg, while DOP has the lowest concentration (0.04 mg/kg). The concentration of PAEs typically decreases as the depth in the soil profile increases. In older landfills, concentrations of PAE decrease significantly, possibly due to long-term degradation and conversion of PAE into other chemical compounds. Future research should prioritize evaluating the effectiveness of landfill liners and waste management practices in preventing the release of PAE and other pollutants into the environment. It is also possible to focus on developing efficient physical, biological, and chemical methods for removing PAEs from landfill leachates. Additionally, the effectiveness of existing treatment processes in removing PAEs from landfill leachates and the necessity for new treatment processes can be considered.

Microplastics and plastisphere at surface waters in the Southwestern Caribbean sea

Pollution generated by plastic waste has brought an environmental problem characterized by the omnipresence of smaller pieces of this material known as microplastics (MP). This issue was addresses by collecting samples with 250 μm pore size nets in two marine-coastal sectors of Southwestern Caribbean Sea during two contrasting seasons. Higher concentrations were found in rainy season than in dry season, reaching respectively 1.72 MP/m3 and 0.22 MP/m3. Within each sector, there were differences caused firstly by localities of higher concentrations of semi-closed water bodies localities during rainy season (Ciénaga Grande de Santa Marta and La Caimanera marsh), and secondly by lower concentrations of localities with less influenced of flow rates during dry season (Salamanca and Isla Fuerte). Moreover, the lowest concentration in dry season corresponding to La Caimanera marsh reflects how the community environmental management might decrease MP pollution. In both sectors and seasons, the particles of 0.3 mm (0.3-1.4 mm) size class dominated over those of 1.4 mm (1.4-5.0 mm) (reaching each respectively 1.33 MP/m3 and 0.39 MP/m3), with a dominance of fibers, except in the rainy season in Magdalena, where they were films. Using the FTIR technique, polypropylene was identified as the most abundant polymer in both sectors. The composition of the assemblage of microorganisms attached to microplastics presented higher richness and differed from that of free-living planktonic microbes. The most abundant members of the plastisphere were proteobacteria whose major representation was the pathogenic genus Vibrio, while the cyanobacteria dominated in seawater samples.

Distribution and composition of seafloor litter and associated macrofouling organisms in the Northeastern Mediterranean Sea

Composition, and density of marine litter and associated macrofouling organisms was assessed in the continental shelf of the Northeastern Mediterranean Sea. A total of 943 litter items weighing 388 kg were collected during 34 hauls. Plastic comprised 72 % of the total litter found on the seafloor. The mean number and weight of ML was 4241 ± 1333 items/km2 and 368 ± 87 kg/km2. Depth and distance from the shore were not identified as a significant factor affecting both the number and weight of litter. A total of 20 fouling species and eggs belonging to Mollusca, Porifera, Cnidaria, Bryozoa, Annelida, Arthropoda, and Chordata were found on marine litter. An alien Mollusca species Pinctada imbricate was also found on plastic litter. Our results confirmed that marine litter is a vector transporting a variety of organisms including alien species and being a threat for the biodiversity and human health in the Mediterranean Sea.

Monitoring plastic pellet pollution in coastal environments through handheld Raman spectroscopy: Data from the Mediterranean coasts (Southern Italy)

This paper examines the distribution and chemical properties of beached plastic pellets along the Ionian and Tyrrhenian coasts of Southern Italy. Three locations have been sampled: Agnone Bagni (SR) and Paradiso (ME) on the Ionian coast of Sicily, Baia del Tono in Milazzo (ME) on the Sicilian Tyrrhenian coast, and Pizzo Calabro (VV) in Calabria on the Tyrrhenian coast. Variations in shape, size, compactness, color, and other physical features, correlated with residence times and transport, has been highlighted. Raman spectroscopy, used in a portable configuration, enabled rapid identification of polymer types, demonstrating its utility for on-site plastic pollutant monitoring. Polyethylene and polypropylene were the predominant polymers. Principal component analysis of the spectra determined the optimal chemometric classification of pellets by composition, avoiding interference or distortion. In conclusion, the study provided preliminary insights into pellet abundance, composition, weathering extent, and distribution across these shorelines, underscoring the importance of regular beach monitoring.

Can plastic related chemicals be indicators of plastic ingestion in an Arctic seabird?

For decades, the northern fulmar (Fulmarus glacialis) has been found to ingest and accumulate high loads of plastic due to its feeding ecology and digestive tract morphology. Plastic ingestion can lead to both physical and toxicological effects as ingested plastics can be a pathway for hazardous chemicals into seabirds' tissues. Many of these contaminants are ubiquitous in the environment and the contribution of plastic ingestion to the uptake of those contaminants in seabirds' tissues is poorly known. In this study we aimed at quantifying several plastic-related chemicals (PRCs) -PBDE209, several dechloranes and several phthalate metabolites- and assessing their relationship with plastic burdens (both mass and number) to further investigate their potential use as proxies for plastic ingestion. Blood samples from fulmar fledglings and liver samples from both fledgling and non-fledgling fulmars were collected for PRC quantification. PBDE209 and dechloranes were quantified in 39 and 33 livers, respectively while phthalates were quantified in plasma. Plastic ingestion in these birds has been investigated previously and showed a higher prevalence in fledglings. PBDE209 was detected in 28.2 % of the liver samples. Dechlorane 602 was detected in all samples while Dechloranes 601 and 604 were not detected in any sample. Dechlorane 603 was detected in 11 individuals (33%). Phthalates were detected in one third of the analysed blood samples. Overall, no significant positive correlation was found between plastic burdens and PRC concentrations. However, a significant positive relationship between PBDE209 and plastic number was found in fledglings, although likely driven by one outlier. Our study shows the complexity of PRC exposure, the timeline of plastic ingestion and subsequent uptake of PRCs into the tissues in birds, the additional exposure of these chemicals via their prey, even in a species ingesting high loads of plastic.

Developmental toxicity of pre-production plastic pellets affects a large swathe of invertebrate taxa

Microplastics pose risks to marine organisms through ingestion, entanglement, and as carriers of toxic additives and environmental pollutants. Plastic pre-production pellet leachates have been shown to affect the development of sea urchins and, to some extent, mussels. The extent of those developmental effects on other animal phyla remains unknown. Here, we test the toxicity of environmental mixed nurdle samples and new PVC pellets for the embryonic development or asexual reproduction by regeneration of animals from all the major animal superphyla (Lophotrochozoa, Ecdysozoa, Deuterostomia and Cnidaria). Our results show diverse, concentration-dependent impacts in all the species sampled for new pellets, and for molluscs and deuterostomes for environmental samples. Embryo axial formation, cell specification and, specially, morphogenesis seem to be the main processes affected by plastic leachate exposure. Our study serves as a proof of principle for the potentially catastrophic effects that increasing plastic concentrations in the oceans and other ecosystems can have across animal populations from all major animal superphyla.

Adsorption of Macrolide Antibiotics and a Metabolite onto Polyethylene Terephthalate and Polyethylene Microplastics in Aquatic Environments

Microplastics (MPs) and antibiotics are emerging pollutants widely found in aquatic environments, potentially causing environmental harm. MPs may act as carriers for antibiotics, affecting their environmental distribution. This study investigates the adsorption of four macrolide antibiotics and a metabolite onto two types of MPs: polyethylene terephthalate (PET) and polyethylene (PE). Results revealed a linear isotherm adsorption model, with higher adsorption to PET than to PE (R2 > 0.936 for PE and R2 > 0.910 for PET). Hydrophobic interactions and hydrogen bonding could be the main adsorption mechanisms, with pore filling potentially involved. Reduced particle size enhances adsorption due to the increase of active adsorption sites. This increasement is more pronounced in PE than in PET, leading to an 11.6% increase in the average adsorption of all macrolides to PE, compared to only 5.1% to PET. Dissolved organic matter inhibits adsorption (azithromycin adsorption to PE was reduced from 12% to 5.1%), while salinity enhances it just until 1% salinity. pH slightly influences adsorption, with maximal adsorption at neutral pH. Results in real samples showed that complexity of the matrix decreased adsorption. Overall, these findings indicate that PE and PET MPs can be a vector of macrolides in aquatic environments.

Effects of primary leachates of conventional and alternative plastics in Cyprinodon variegatus fish larvae: Endocrine disruption and toxicological responses

The inclusion of hazardous substances in the formulation of plastics raises significant concerns, particularly, if those substances are released as primary leachates during plastic degradation and/or fragmentation. In this sense, the production of degradable plastics holding deleterious additives can increase the release of harmful substances into the environment. Additionally, the effects of primary leachates of "eco-friendly" materials remain unexplored. To address this, we performed exposures to primary leachates of alternative polymers, and commercial bags to verify possible responses associated with endocrine disruption and/or activation of the detoxification pathway in larvae of the marine fish model Cyprinodon variegatus. The chemical characterization evidenced a great number of additives in the formulation of the materials analyzed in this study. Those include, except for the PLA sample, relevant levels of the hazardous phthalates DEHP and DiBP. Regarding the effects on marine fish larvae, exposure to leachates from alternative polymers (10 g/L) PHB and PHBV produced remarkable mortality (100%). While the exposure to bag leachates of all tested materials (1 and 10 g/L) produced alterations in biomarkers for steroidogenic and detoxification pathways. To a lesser extent (10 g/L), three materials produced significant alterations in estrogenic biomarkers (Home-compostable bag 1, LDPE and Recycled PE bags). Although the alterations in gene expression were not directly correlated to the amount of DEHP or DiBP, we can conclude that primary leachates of "eco-friendly" bags are harmful to marine vertebrates.

Effect of Biofilm Forming on the Migration of Di(2-ethylhexyl)phthalate from PVC Plastics

Plastic additives, represented by plasticizers, are important components of plastic pollution. Biofilms inevitably form on plastic surfaces when plastic enters the aqueous environment. However, little is known about the effect of biofilms on plastic surfaces on the release of additives therein. In this study, PVC plastics with different levels of di(2-ethylhexyl)phthalate (DEHP) content were investigated to study the effect of biofilm growth on DEHP release. The presence of biofilms promoted the migration of DEHP from PVC plastics to the external environment. Relative to biofilm-free controls, although the presence of surface biofilm resulted in 0.8 to 11.6 times lower DEHP concentrations in water, the concentrations of the degradation product, monoethylhexyl phthalate (MEHP) in water, were 2.3 to 57.3 times higher. When the total release amounts of DEHP in the biofilm and in the water were combined, they were increased by 0.6-73 times after biofilm growth. However, most of the released DEHP was adsorbed in the biofilms and was subsequently degraded. The results of this study suggest that the biofilm as a new interface between plastics and the surrounding environment can affect the transport and transformation of plastic additives in the environment through barrier, adsorption, and degradation. Future research endeavors should aim to explore the transport dynamics and fate of plastic additives under various biofilm compositions as well as evaluate the ecological risks associated with their enrichment by biofilms.

Microplastics and nanoplastics: Source, behavior, remediation, and multi-level environmental impact

Plastics introduced into the natural environment persist, degrade, and fragment into smaller particles due to various environmental factors. Microplastics (MPs) (ranging from 1 μm to 5 mm) and nanoplastics (NPs) (less than 1 μm) have emerged as pollutants posing a significant threat to all life forms on Earth. Easily ingested by living organisms, they lead to ongoing bioaccumulation and biomagnification. This review summarizes existing studies on the sources of MPs and NPs in various environments, highlighting their widespread presence in air, water, and soil. It primarily focuses on the sources, fate, degradation, fragmentation, transport, and ecotoxicity of MPs and NPs. The aim is to elucidate their harmful effects on marine organisms, soil biota, plants, mammals, and humans, thereby enhancing the understanding of the complex impacts of plastic particles on the environment. Additionally, this review highlights remediation technologies and global legislative and institutional measures for managing waste associated with MPs and NPs. It also shows that effectively combating plastic pollution requires the synergization of diverse management, monitoring strategies, and regulatory measures into a comprehensive policy framework.

Dynamics and effects of plastic contaminants' assimilation in gulls

Polybrominated diphenyl ethers are persistent disrupters assimilated by organisms, yet little is known about their link to plastic ingestion and health effects. In an experiment, two groups of yellow-legged/lesser black-backed gulls (Larus michahellis/Larus fuscus) were fed plastics with BDE99 to assess leaching into brain, preen oil, liver and fat tissues and evaluate effects on health and stress parameters. Although most plastic was regurgitated, we observed a clear relation between plastic ingestion and chemical leaching. BDE99 exhibited higher levels in brain tissue of gulls from the plastic groups. Also, only values of cholinesterases measured in plasma were significantly reduced in the 'plastic' groups. Cholinesterase activity in the brain also tended to decrease, suggesting a negative effect in gulls' neurofunction. Results indicate that chemical leaching occurs, even when plastics stay in the stomach for a short period of time and showed that this can affect gulls' health.

Assessment of microplastic contamination in shrimps from the Bay of Bengal and associated human health risk

Microplastics (MPs) were analyzed in seven shrimp species Tiger shrimp (Penaeus monodon), Red tiger shrimp (Caridina cantonensis), Indian shrimp (Penaeus indicus), Red shrimp (Metapenaeus dobsoni), White shrimp (Penaeus merguiensis), Brown shrimp (Metapenaeus monoceros), and Roshna shrimp (Palaemon styliferus) collected from the Bay of Bengal. The abundance and characteristics of MPs were assessed in the gastrointestinal tract (GIT), which certainly translocated to the muscle of shrimp species. The highest MP abundance was found in C. cantonensis with 7.2 items/individual (25.3 items/g in the GIT and 6.3 items/g in muscle). The prominent types of MPs in shrimp samples were fibers (30 %) and fragments (29 %). The ingestion rate of MPs of black and transparent color was comparatively higher, with 64 % of the ingested MPs were < 100 μm. The primary polymer types detected based on Fourier Transform Infrared (FTIR) analysis were Low-Density Polyethylene (LDPE), High-Density Polyethylene (HDPE), Polymethyl Methacrylate (PMMA), Polyvinyl Chloride (PVC), Polypropylene (PP), and Ethylene Vinyl Acetate (EVA). Results from Scanning Electron Microscopy (SEM) showed rough surface textures and adhered particles on the MPs isolated from shrimps. The margin of exposure for females was 71.42, and for males, it was 80.64, indicating that women in Bangladesh are more likely to be exposed to MPs and face a higher risk than men. Sensitivity analysis revealed that MPs particle size was the most sensitive parameter. These findings provide a comprehensive understanding of MP ingestion, human exposure, and contamination in shrimps of Bangladesh, which can help future monitoring efforts.

Naked-eye sensitive detection of nanoPET by pH-responsive colorimetric method based on dual-enzyme catalysis

A pH-responsive colorimetric method based on dual-enzyme catalysis for rapid and facile detection and quantification of nanoPET at environment-dependent concentration is proposed. The nanoPET was hydrolyzed by the synergistic catalysis of cutinase and lipase to terephthalic acid which can be sensitive detected using bromocresol purple as the indicator. The color changed from purple to bright yellow as the nanoPET detection concentration increased from 0 mg/mL to 2 mg/mL which can be detected by UV-Vis. This naked-eye method has a high sensitivity for nanoPET detection with the visual detection cutoff of 31.00 μg/mL, and has a good linearity in the range of 0 ∼ 1 mg/mL with LOD of 22.84 μg/mL. The reliability of this method is verified in the detection of nanoPET in lake water and beer samples, with an average recovery of 87.1 %. The as-developed dual-enzyme colorimetric chemosensor holds promising potential as a robust and effective platform for the sensitive detection of nanoPET.

Interaction of microplastics with heavy metals in soil: Mechanisms, influencing factors and biological effects

Microplastics (MPs) and heavy metals (HMs) in soil contamination are considered an emerging global problem that poses environmental and health risks. However, their interaction and potential biological effects remain unclear. Here, we reviewed the interaction of MPs with HMs in soil, including its mechanisms, influencing factors and biological effects. Specifically, the interactions between HMs and MPs mainly involve sorption and desorption. The type, aging, concentration, size of MPs, and the physicochemical properties of HMs and soil have significant impacts on the interaction. In particular, MP aging affects specific surface areas and functional groups. Due to the small size and resistance to decomposition characteristics of MPs, they are easily transported through the food chain and exhibit combined biological effects with HMs on soil organisms, thus accumulating in the human body. To comprehensively understand the effect of MPs and HMs in soil, we propose combining traditional experiments with emerging technologies and encouraging more coordinated efforts.

Microbial degradation of low-density polyethylene, polyethylene terephthalate, and polystyrene by novel isolates from plastic-polluted environment

Biodegradation is an eco-friendly measure to address plastic pollution. This study screened four bacterial isolates that were capable of degrading recalcitrant polymers, i.e., low-density polyethylene, polyethylene terephthalate, and polystyrene. The unique bacterial isolates were obtained from plastic polluted environment. Dermacoccus sp. MR5 (accession no. OP592184) and Corynebacterium sp. MR10 (accession no. OP536169) from Malaysian mangroves and Bacillus sp. BS5 (accession no. OP536168) and Priestia sp. TL1 (accession no. OP536170) from a sanitary landfill. The four isolates showed a gradual increase in the microbial count and the production of laccase and esterase enzymes after 4 weeks of incubation with the polymers (independent experiment set). Bacillus sp. BS5 produced the highest laccase 15.35 ± 0.19 U/mL and showed the highest weight loss i.e., 4.84 ± 0.6% for PS. Fourier transform infrared spectroscopy analysis confirmed the formation of carbonyl and hydroxyl groups as a result of oxidation reactions by enzymes. Liquid chromatography-mass spectrometry analysis showed the oxidation of the polymers to small molecules (alcohol, ethers, and acids) assimilated by the microbes during the degradation. Field emission scanning electron microscopy showed bacterial colonization, biofilm formation, and surface erosion on the polymer surface. The result provided significant insight into enzyme activities and the potential of isolates to target more than one type of polymer for degradation.

Microplastic contamination in wastewater: Sources, distribution, detection and remediation through physical and chemical-biological methods

Microplastics are tiny plastic particles smaller than 5 mm. that have been widely detected in the environment, including in wastewater. They originate from various sources including breakdown of larger plastic debris, release of plastic fibres from textiles, and microbeads commonly used in personal care products. In wastewater, microplastics can pass through the treatment process and enter the environment, causing harm to biodiversity by potentially entering the food chain. Additionally, microplastics can act as a vector for harmful pollutants, increasing their transport and distribution in the environment. To address this issue, there is a growing need for effective wastewater treatment methods that can effectively remove microplastics. Currently, several physical and chemical methods are available, including filtration, sedimentation, and chemical degradation. However, these methods are costly, low efficiency and generate secondary pollutants. Furthermore, lack of standardization in the measurement and reporting of microplastics in wastewater, makes it difficult to accurately assess microplastic impact on the environment. In order to effectively manage these issues, further research and development of effective and efficient methods for removing microplastics from wastewater, as well as standardization in measurement and reporting, are necessary to effectively manage these detrimental contaminants.

Empowering Strategies for Lifestyle Interventions, Diet Modifications, and Environmental Practices for Uterine Fibroid Prevention; Unveiling the LIFE UP Awareness

Uterine fibroids (UFs) are the most common prevalent benign tumor among women of reproductive age, disproportionately affecting women of color. This paper introduces an innovative management strategy for UFs, emphasizing the curbing of disease prevention and progression. Traditionally, medical intervention is deferred until advanced stages, necessitating invasive surgeries such as hysterectomy or myomectomy, leading to high recurrence rates and increased healthcare costs. The strategy, outlined in this review, emphasizes UF disease management and is named LIFE UP awareness-standing for Lifestyle Interventions, Food Modifications, and Environmental Practices for UF Prevention. These cost-effective, safe, and accessible measures hold the potential to prevent UFs, improve overall reproductive health, reduce the need for invasive procedures, and generate substantial cost savings for both individuals and healthcare systems. This review underscores the importance of a proactive UF management method, paving the way for future research and policy initiatives in this domain.

Microplastic pollution in waters of the Antarctic coastal environment of Potter Cove (25 de Mayo Island/King George Island, South Shetlands)

Plastic pollution in the Southern Ocean around Antarctica is a growing concern, but many areas in this vast region remain unexplored. This study provides the first comprehensive analysis of marine microplastic (MPs) concentrations in Potter Cove, located near the Argentinian Carlini research station on 25 de Mayo/King George Island, Antarctica. Water samples were collected at 14 sites within the cove, representing various influences from the station's activities. Two sampling methods were used: a 5 L Niskin bottle and an in-situ filtering device called Microfilter, allowing for large water volumes to be filtered. MPs were found in 100 % of the samples. Microfilter samples ranged from 0.02 to 2.14 MPs/L, with a mean concentration of 0.44 ± 0.44 MPs/L. Niskin bottle samples showed concentrations from 0.40 to 55.67 MPs/L, with a mean concentration of 19.03 ± 18.21 MPs/L. The dominant types of MPs were anthropogenic black, transparent, and pink microfibers (MFs) measuring between 0.11 and 3.6 mm (Microfilter) and 0.06 to 7.96 mm (Niskin bottle), with a median length of 0.01 mm for both methods. Transparent and black irregular microfragments (MFRs) with diameters from 0.10 to 5.08 mm and a median diameter of 0.49 mm were also prevalent. FTIR-spectroscopy revealed the presence of 14 types of polymers. Cellulose-based materials and polyethylene terephthalate were the most abundant in MFs, while polyurethanes and styrene-based copolymers dominated in MFRs. MPs were more abundant near the Carlini station. Compared to other coastal Antarctic areas, the MPs in the cove were relatively abundant and mostly smaller than 1 mm. Local activities on the island were identified as the primary source of MPs in the cove, and the cyclonic water circulation likely affects the distribution of small-sized particles. To protect the ecosystem, reducing plastic usage, improving waste management, regulating MPs debris, and enhancing wastewater practices are essential.

Toxic effects on ciliates under nano-/micro-plastics coexist with silver nanoparticles

Owing to the degradation of plastics, microplastics (MPs) and nanoplastics (NPs) have remained the focus of global attention. Silver nanoparticles (AgNPs) could adversely affect marine organisms due to their broad application. So far, the combined effects of MPs/NPs (strong adsorbents) with AgNPs on marine organisms are scant. Thus, four sizes polystyrene beads (80 nm, 220 nm, 1.07 µm, and 2.14 µm) combined with AgNPs (30 nm) were assessed using ciliated protozoa Uronema marinum. Results showed that MPs/NPs dramatically decrease the abundance, biovolume, and carbon biomass of U. marinum. And, exposure could cause changes of antioxidant enzyme activity and antioxidant content on U. marinum. The combined toxicity of MPs/NPs with AgNPs to ciliates showed an enhanced effect compared to exposure alone. Additionally, the negative effects under exposure of NPs plus AgNPs were more significant than those of MPs plus AgNPs. Transcriptome sequencing showed that co-exposure could affect the energy metabolism and lipid metabolism of ciliates, even cause DNA and protein damage. Our study provided a novel insight and first-hand basic data for the understanding of combined toxicity of MPs /NPs with AgNPs on the basic trophic level ciliated protozoa in marine ecosystems.

The importance of integrating morphological attributes of microplastics: a theoretical discussion to assess environmental impacts

Most scientific studies on microplastic (MP) pollution report their results as number of particles (e.g., particles/m2, particles/m3, particles/kg dw). An important limitation of this expression is to consider all MP particles as environmentally equivalent, regardless of their size, volume, mass, or specific surface area. Using a theoretical approach, we advocate that including such morphological attributes reveals significant differences in results of supposedly equivalent samples that consider only the number of particles. Our goal is to present how particle size and shape produce different results for hypothetical samples with the same number of particles. Therefore, from these examples we expect to stimulate the debate and contribute to improve accuracy and comparability of studies on MP pollution.

Microplastic leachates inhibit small-scale self-organization in mussel beds

Self-organized spatial patterns are increasingly recognized for their contribution to ecosystem functioning. They can improve the ecosystem's ability to respond to perturbation and thus increase its resilience to environmental stress. Plastic pollution has now emerged as major threat to aquatic and terrestrial biota. Under laboratory conditions, we tested whether plastic leachates from pellets collected in the intertidal can impair small-scale, spatial self-organization and byssal threads production of intertidal mussels and whether the effect varied depending on where the pellets come from. Specifically, leachates originating from plastic pellets collected from relatively pristine and polluted areas respectively impaired and inhibited the ability of mussels to self-organize at small-scale and to produce byssal threads compared to control conditions (i.e., seawater without leaching solution). Limitations to natural self-organizing processes and threads formation may translate to a declined capacity of natural ecosystems to avoid tipping points and to a reduced restoration success of disturbed ecosystems.

Nano polystyrene microplastics could accumulate in Nile tilapia (Oreochromis niloticus): Negatively impacts on the intestinal and liver health through water exposure

Microplastics (MPs) have become a significant concern for their potential toxicity. However, the correlation between the size of plastic particles and their toxicity remains inconclusive. Here, we investigate the toxic effects of different sizes (80 nm, 800 nm, 8 µm and 80 µm) polystyrene MPs (PS-MPs) on the model organism Nile tilapia (Oreochromis niloticus). The results of bioluminescent imaging indicate that the 80 nm PS-MPs are more likely to invade the body. H&E staining shows severe damage on the intestinal villi and distinct hepatic steatosis in the 80 nm group. EdU labeling shows that the proliferation activity of intestinal and liver cells reduces significantly in the 80 nm group. The gut microbiome analysis shows a severe imbalance of gut microbiota homeostasis in the 80 nm group. The analysis of liver transcriptomics and metabolomics shows that the liver lipid metabolism is disordered in the 80 nm group. In conclusion, this study confirms that the 80 nm PS-MPs are more likely to induce intestinal and liver toxicity. All the above lay the foundation for further study on the pathological damage of MPs to other organisms.

Temporal dynamics of bacterial colonization on five types of microplastics in a freshwater lake

Microplastics (MPs), as a new substrate, provide a unique niche for microbial colonization in the freshwater ecosystems; however, the impacts of long-term MP exposure on colonized bacteria are still unclear. In this study, five MP types were exposed in a freshwater lake for approximately one year, and the MP particles, together with the surrounding water, were collected on days 60, 150, 250 and 330 during the in situ field experiment. Bacteria on the MP surface, as well as free-living bacteria in the surrounding water, were analyzed to evaluate the temporal dynamics of these bacterial communities. Results show that all five MP types exhibited signs of degradation during the exposure process. Additionally, the alpha diversity, community structure and composition of MP-attached bacteria significantly differed from that of the free-living bacteria in the surrounding water, indicating that the five MP types could provide a preferable niche for bacterial colonization in a freshwater environment. Proteobacteria, Chloroflexi, Verrucomicrobiota, Actinobacteriota and Firmicutes were the top five dominant phyla. Some plastic-degrading bacteria included in these phyla were detected, verifying that MP-attached biofilms had a certain degree of MP degradation potential. Some potentially pathogenic bacteria were also detected, suggesting an ecological threat for spreading disease in the aquatic ecosystem. Furthermore, the bacterial community and some metabolic pathways were significantly affected by the MP type (P < 0.01) and exposure time (P < 0.01), indicating that the presence of MPs not only alters the bacterial community structure and composition, but also influences their potential functional properties in freshwater ecosystems. Multiple factors, including the physicochemical properties related to MPs and the environmental parameters of the surrounding water, affect the community composition and the function of MP-attached bacteria to different degrees. Our findings indicate that the presence of MPs has a potential ecological impact on freshwater ecosystems.

Microplastic pollution: a review of techniques to identify microplastics and their threats to the aquatic ecosystem

Microplastics (MPs), small synthetic particles, have emerged as perilous chemical pollutants in aquatic habitats, causing grave concerns about their disruptive effects on ecosystems. The fauna and flora inhabiting these specific environments consume these MPs, unwittingly introducing them into the intricate web of the food chain. In this comprehensive evaluation, the current methods of identifying MPs are amalgamated and their profound impacts on marine and freshwater ecosystems are discussed. There are many potential risks associated with MPs, including the dangers of ingestion and entanglement, as well as internal injuries and digestive obstructions, both marine and freshwater organisms. In this review, the merits and limitations of diverse identification techniques are discussed, including spanning chemical analysis, thermal identification, and spectroscopic imaging such as Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and fluorescent microscopy. Additionally, it discusses the prevalence of MPs, the factors that affect their release into aquatic ecosystems, as well as their plausible impact on various aquatic ecosystems. Considering these disconcerting findings, it is imperative that appropriate measures should be taken to assess the potential risks of MP pollution, protect aquatic life and human health, and foster sustainable development.

Levels of persistent organic pollutants (POPs) and the role of anthropic subsidies in the diet of avian scavengers tracked by stable isotopes

Persistent Organic Pollutants (POPs) have been identified as a significant factor driving declines in wildlife populations. These contaminants exhibit a dual tendency to biomagnify up the food chains and persist within tissues, rendering long-lived vertebrates, such as raptors, highly vulnerable to their adverse effects. We assessed the concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in fledglings of two vulture species, the Egyptian vulture (Neophron percnopterus) and the griffon vulture (Gyps fulvus), coexisting in northern Spain. Vultures, currently facing a severe threat with a population decline exceeding 90%, represent one of the most critically endangered avian groups in the Old World. Despite this critical situation, there remains a scarcity of research examining the intricate relationship between contaminant levels and individual foraging behaviors. In parallel, we analyzed stable isotope levels (δ15N and δ13C) in fledgling's feathers and prey hair to determine the association between individual dietary and contaminant burdens. Our findings revealed higher levels of PCBs in Egyptian vultures, while pesticide concentrations remained very similar between focal species. Furthermore, higher individual values of δ13C, indicating a diet based on intensive farming carcasses and landfills, were associated with higher levels of PCBs. While the levels of POPs found do not raise immediate alarm, the presence of individuals with unusually high values reveals the existence of accessible contamination sources in the environment for avian scavengers. The increasing reliance of these birds on intensive livestock farming and landfills, due to the decline of extensive livestock farming, necessitates long-term monitoring of potential contaminant effects on their populations.

Trophic transfer and their impact of microplastics on estuarine food chain model

Microplastic contamination in marine ecosystems, and its negative effects through trophic transfer among marine organisms, remains a growing concern. Our study investigates the trophic transfer and individual impacts of polystyrene microplastics (MPs) in an estuarine food chain model, comprising Artemia salina as primary organism, Litopenaeus vanamei as secondary organism, and Oreochromis niloticus as tertiary organism. A. salina were exposed to 1 µm polystyrene microplastics (106 particles/ml), further it was fed to L.vannamei, which, in turn, were fed to O.niloticus. MPs transfer was studied over 24 and 48 h. Fluorescence microscopy confirmed MPs presence in the gut and fecal matter of all the test organisms. Histopathology revealed MPs in the gut epithelium, but did not translocate to other tissues of the test species. MPs exposed A.salina had a bioconcentration factor of 0.0029 ± 0.0008 (24 h) and 0.0000941 ± 0.0000721 (48 h). Whereas, the bioaccumulation factor values for L. vanamei were 0.00012143 ± 0.000009 (24 h) and 0.0025899 ± 0.0024101 (48 h), and for O.niloticus were 0.154992 ± 0.007695 (24 h) and 0.00972577 ± 0.00589923 (48 h). Despite low MPs transfer among trophic levels, the induced stress was evident through biochemical responses in all the test species. This implies the potential risk of MPs ultimately reaching humans via the food chain.

Various additive release from microplastics and their toxicity in aquatic environments

Additives may be present in amounts higher than 50% within plastic objects. Additives in plastics can be gradually released from microplastics (MPs) into the aquatic environment during their aging and fragmentation because most of them do not chemically react with the polymers. Some are known to be hazardous substances, which can cause toxicity effects on organisms and pose ecological risks. In this paper, the application of functional additives in MPs and their leaching in the environment are first summarized followed by their release mechanisms including photooxidation, chemical oxidation, biochemical degradation, and physical abrasion. Important factors affecting the additive release from MPs are also reviewed. Generally, smaller particle size, light irradiation, high temperature, dissolved organic matter (DOM) existence and alkaline conditions can promote the release of chemicals from MPs. In addition, the release of additives is also influenced by the polymer's structure, electrolyte types, as well as salinity. These additives may transfer into the organisms after ingestion and disrupt various biological processes, leading to developmental malformations and toxicity in offspring. Nonetheless, challenges on the toxicity of chemicals in MPs remain hindering the risk assessment on human health from MPs in the environment. Future research is suggested to strengthen research on the leaching experiment in the actual environment, develop more techniques and analysis methods to identify leaching products, and evaluate the toxicity effects of additives from MPs based on more model organisms. The work gives a comprehensive overview of current process for MP additive release in natural waters, summarizes their toxicity effects on organisms, and provides recommendations for future research.

Effect of plastic mulch residue on plant growth performance and soil properties

Plastic mulch is widely utilized for weed control, temperature regulation, soil erosion prevention, disease management, and soil structure improvement, ultimately enhancing crop quality and yield. However, a significant issue with conventional plastic mulches is their low recycling rates, which can cause plastic residue to build up, thereby damaging soil quality and reducing crop yield. The emergence of biodegradable films offers a promising solution to mitigate this issue and reduce soil pollution. However, its potential effects on soil properties and plant performance remain unclear. In this study, low-density polyethylene (LDPE) and poly (butylene succinate-co-butylene adipate) (PBSA) were used to observe the effect of plastic mulch residues on soil properties and plant growth performance via potting experiment. Additionally, the interaction effects of compost and biochar as soil amendments with plastic mulch residues were also evaluated. The result of this study revealed that the type of plastic significantly affected the total nitrogen and magnesium uptake; however, the morphological traits of the tested plant (Japanese mustard spinach) were not significantly affected. The addition of compost and biochar led to a significant increase in both shoot and total dry weight of the plant, indicating a positive effect on its growth. The results of the two-way ANOVA indicated a significant influence of plastic type on dissolved phosphate (PO43-) levels and soil dehydrogenase activity (DHA). The interaction effect (plastic type with soil amendment) was statistically significant only for soil DHA. Neither plastic mulch residues nor soil amendments significantly affected other soil chemical properties. However, long-term experiments to systematically investigate the long-term effects of plastic residues are necessary.

Plastic pellets make Excirolana armata more aggressive: Intraspecific interactions and isopod mortality differences between populations

Plastic pellets represent a significant component of microplastic (< 5 mm) pollution. Impacts caused by plastic pellets involve physical harm and toxicity related to ingestion and non-ingestion (such as the release of chemicals in leachates). The latter is the main route of exposure for invertebrate macrobenthic populations. This study aimed to compare the toxicity of plastic pellets in distinct marine macrobenthic populations, considering the influence of sediment characteristics (organic matter and grain size) and quality (contamination by hydrophobic chemicals) on ecotoxicological effects, as well as the influence of color on the toxicity of beach-stranded plastic pellets. We performed three experiments on plastic pellet exposure using Excirolana armata from beaches with high and low pellet density. When exposed to pellets, populations that inhabit beaches without pellets demonstrate higher mortality than those inhabiting beaches with high pellet densities. The mortality of E. armata to pellets was higher when the exposure occurred in sediment with high organic matter (OM), suggesting that chemicals were transferred from pellets to OM. Yellowish beach-stranded pellets induced higher mortality of E. armata than the white tones did. We also observed lethargic (near-dead) and dead individuals being preyed upon by healthy individuals, a cannibalistic behavior that raises an ecological concern regarding the negative effects of this exposure on intraspecific interactions in marine macrobenthic populations.

Micro- and nanoplastics interact with conventional pollutants on microalgae: Synthesis through meta-analysis

Micro- and nanoplastics (MNPs) have been found to occur intensively in aquatic environments, along with other conventional pollutants (Po) such as heavy metals, pesticides, pharmaceuticals, etc. However, our understanding of how MNPs and Po interact on aquatic primary producers is fragmented. We performed a quantitative meta-analysis based on 933 published experimental assessments from 44 studies to examine the coupled effects of MNPs and Po on microalgae. Although the results based on interaction type frequency (the proportion of each interaction type in all results) revealed dominantly additive interactions (56%) for overall physiological performance, an overall antagonistic effect was observed based on the mean interaction effect sizes. A higher proportion of antagonistic interaction type frequency was found in marine species compared to fresh species. The antagonistic effects were particularly significant for growth, oxidative responses, and photosynthesis, which could be attributed to the adsorption effect of MNPs on Po and thus the decreasing concentrations of pollutants in the medium. Larger-sized, negatively charged or uncharged and aged MNPs had higher proportions of antagonistic effects compared to smaller-sized, positively charged and virgin MNPs, due to their stronger adsorption capacity to Po. This study provides a comprehensive insight into the interactive effects of MNPs and Po on microalgae.

Aging of plastics in aquatic environments: Pathways, environmental behavior, ecological impacts, analyses and quantifications

The ubiquity of plastics in our environment has brought about pressing concerns, with their aging processes, photo-oxidation, mechanical abrasion, and biodegradation, being at the forefront. Microplastics (MPs), whether originating from plastic degradation or direct anthropogenic sources, further complicate this landscape. This review delves into the intricate aging dynamics of plastics in aquatic environments under various influential factors. We discuss the physicochemical changes that occur in aged plastics and the release of oxidation products during their degradation. Particular attention is given to their evolving environmental interactions and the resulting ecotoxicological implications. A rigorous evaluation is also conducted for methodologies in the analysis and quantification of plastics aging, identifying their merits and limitations and suggesting potential avenues for future research. This comprehensive review is able to illuminate the complexities of plastics aging, charting a path for future research and aiding in the formulation of informed policy decisions.

The seasonality of the concentration of endocrine phenolic compounds in the matter attached to the surface of microplastics

Rapid biofilm formation on microplastic (MP) surfaces in marine environments and the tendency of hydrophobic pollutants to bioaccumulate may increase the exposure of organisms to ingested plastics and transport pollutants far from their sources. The role of the matter attached to MPs (MaM) in the interactions between MPs and other pollutants in marine environments is poorly understood. This paper studies pollutant sorption in MaM for three phenolic endocrine-disrupting chemicals (EDCs): bisphenol A (BPA), 4-tert-octylphenol (4-t-OP), and 4-nonylphenol (4-NP). Polypropylene (PP), expanded polystyrene (EPS), and polylactide (PLA) MPs were exposed to an environment conducive to biofouling (Vistula Lagoon, Baltic Sea) for four weeks in summer, spring, and winter. The concentrations of EDCs in MaM and the suspended particulate matter (SPM) were similar and were 2-3 orders of magnitude higher than those in water and sediment. The type and morphology of the polymers were less significant for determining the concentrations of EDCs in MaM than the season. The concentrations were higher in the growing season than in winter. EDCs increased linearly with the increase in particulate organic carbon. The relationships between organic carbon partition coefficients and octanol/water partition coefficients indicate that hydrophobic partitioning into organic matter was the dominant mechanism of 4-t-OP and 4-NP binding in MaM and in SPM. For BPA, additional sorption mechanisms seem to be significant. In addition to the direct sorption from ambient water, the binding of phytoplankton-derived particles, most probably via attachment to extracellular polymeric substances, appears to be a source of EDCs in MPs. Rough estimates showed that the largest load of particulate matter and EDCs was attached to expanded polystyrene. This study suggests that the potential negative impacts of MPs on the environment are seasonal and that low-density porous plastics can be particularly effective carriers of large EDC loads.

Abundance and characterization of microplastic pollution in the wildlife reserve, Ramsar site, recreational areas, and national park in northern Jakarta and Kepulauan Seribu, Indonesia

This is the first study to evaluate the presence and distribution of microplastics in sediments in the regions with a unique degree of complexity, such as wildlife reserve areas, a Ramsar site that connects directly to Greater Jakarta's mainland, recreational islands, and a marine national park. Microplastics of varying sizes and shapes are found in all places, with an increase trend in the abundance toward areas near to the epicenter of human activity. Comparatively to other marine protected areas, the amount of microplastics discovered is comparable; however, there is an upward trend. Season influences microplastic accumulation, with the dry season causing the greater accumulation. Small-sized microplastics and microplastics resulting from large plastic fragments were predominantly discovered. The properties of microplastics in the study region are dominated by polyethylene, polypropylene, polystyrene, polyvinyl chloride, and nylon. Additional in-depth research and waste reduction from all sources that involve all stakeholders are required to reduce the amount of contaminants entering the protected area.