Ecological Effects Of Microplastics Research Articles

Time matters: Why ecological effects of microplastics might change over time

AbstractResearch Highlight: Lozano, Y. M., Gordillo, H., Waldmann, W., & Rillig, M. C. (2023). Photodegradation modifies microplastic effects on soil properties and plant performance. Journal of Applied Ecology, https://doi.org/10.1111/1365‐2664.14514.Plastics are omnipresent in daily life and so is plastic waste in the environment. Once there, plastic waste remains for a long time, slowly disintegrating into ever smaller particles including microplastics (particles <5 mm). Simultaneously, physical and chemical properties of these particles are modified due to aging processes. Although scientific awareness about microplastic effects on terrestrial ecosystems is recently increasing, current studies focused on the effects of pristine microplastics. However, modified properties due to aging could influence microplastic effects on terrestrial ecosystems and their components. In their current study, Lozano et al. provide first evidence that photodegradation can modify the effects of different microplastics on soil properties and plant performance, indicating that degradation could intensify microplastic effects on plant–soil systems. These results emphasise the need to better investigate how the global issue of plastic pollution affects ecosystems, also over the long term, and the need to stop the flow of plastics entering the environment.

Research on Ecological Effects of Microplastics and Removal Methods

In recent years, with the continuous accumulation of microplastics (MPs), the environmental pollution caused by MPs has become increasingly serious. In this paper, whether the accumulation of MPs will cause serious damage to the ecological environment and organisms and if harm is caused, how to eliminate it are analyzed. The results show that MPs are mainly produced by human activities, which have caused pollution to the water environment, soil environment and atmospheric environment. MPs destroying the water cycle, enriching heavy metals in the soil and aggravating the greenhouse effect indirectly threaten the organisms living in the environment. Due to the large amount of MPs enrichment, the survival rate of soil animals and aquatic animals is decreasing year by year, their growth and development are seriously inhibited, and the living conditions are becoming difficult. Because of the blockage of MPs, the ability of plant roots to absorb water is greatly reducing, the activity of various enzymes in the plant body is decreasing, and the efficiency of photosynthesis is affected. As the highest trophic level, humans are naturally not immune to the harm of MPs. The higher the trophic level, the more enriched the content of MPs, which poses a great threat to health. In the future, the elimination of MPs will become a focus of attention. The existing physical treatment method, chemical treatment method and biological treatment method should be improved and reasonably combined to achieve the optimal treatment effect, hoping to reduce the harm of MPs as much as possible.

Additive effects of microplastics on accumulation and toxicity of cadmium in male zebrafish

Microplastics (MPs) have emerged as contaminants of concern because of their ubiquitous presence in almost all aquatic environments. The ecological effects of MPs are complex and depend on multiple factors including their age, size and the ecological matrix. There is an urgent need for multifactorial studies to elucidate their impacts. We measured the effects of virgin and naturally aged MPs, alone, pretreated with cadmium (Cd), or in combination with ionic Cd, on the bioaccumulation of Cd, metallothionein expression, behavior, and histopathology of adult zebrafish (Danio rerio). Zebrafish were exposed to virgin or aged polyethylene MPs (0.1% MPs enriched diets, w/w) or waterborne Cd (50 μg/L) or a combination of the two for 21 days. There was an additive interaction between water-borne Cd and MPs on bioaccumulation in males but not in females. Cd accumulation increased by twofold when water-borne Cd and MPs were combined. Water-borne Cd induced significantly higher levels of metallothionein compared to MPs pre-exposed to Cd. However, Cd-treated MPs caused greater damage to the intestine and liver compared to untreated MPs suggesting that bound Cd could be released or modulate MPs toxicity. We also showed that co-exposure to water-borne Cd and MPs increased anxiety in the zebrafish, compared with water-borne Cd alone, suggesting using microplastics as a vector may increase toxicity. This study demonstrates that MPs can enhance the toxicity of Cd, but further study is needed to elucidate the mechanism.

Occurrence and Effects of Microplastics in Lake Ecosystems: Particular Focus on Migration in Water and Food Chains

Microplastics have become a research hotspot in the environmental field owing to their persistence and complex ecological effects. Although microplastics have attracted public attention only recently, the microplastic pollution in lake, a unique water system characterized by their irreplaceable ecological value and special hydrodynamic conditions, were increasingly documented, calling for a summary of the most recent advance in this research area. Therefore, the sampling and analysis methods, occurrence, sources, and ecological effects of microplastics in lakes were summarized in this review. Various types of plastics are produced and used in large quantities for different purposes, resulting in microplastic pollution being widespread in lakes worldwide, albeit with different levels and characteristics. Microplastics constantly migrate and transform in lake ecosystems, exerting impacts on ecological, including pollution diffusion and biological toxicity. This review focused on the migration of microplastics in water and food chains, which is a different perspective than that considered in previously published reviews. This review also discussed the limitations of existing studies and made recommendations. Future research directions should include the following: 1) improving the baseline database of microplastic pollution in lakes; (2) unifying the sampling and laboratory analysis methods; (3) exploring the quantitative analysis methods of the sources, transportation, and fate of microplastics; (4) considering more factors to explore the effects of microplastics on lake ecosystems.

Effects of heavy metals on the adsorption of ciprofloxacin on polyethylene microplastics: Mechanism and toxicity evaluation

Microplastics are plastic particles less than 5 mm in diameter and are widely present in water environments. Their unique surface structures can adsorb coexisting pollutants in the surrounding environment, such as antibiotics and metal ions, leading to compound pollution. The adsorption of ciprofloxacin on polyethylene microplastics under different environmental conditions (pH and salinity) was investigated. The Freundlich model fitted well at 25 °C, indicating that the adsorption of ciprofloxacin by polyethylene microplastics was multilayered, and Fourier Transform infrared spectroscopy (FTIR) analysis indicated that the adsorption of ciprofloxacin by polyethylene microplastics was physical. The kinetic adsorption of ciprofloxacin on polyethylene microplastics followed a pseudo-second-order mode. Heavy metals (Cu2+, Cr3+, Cr6+, Cd2+, and Pb2+) affected the adsorption of ciprofloxacin by microplastics, which was related to the type and concentration of metal ions and the valence state of the ions. The acute toxicity of microplastics and the microplastic-ciprofloxacin-Cu2+ complex were evaluated using luminescent Photobacterium phosphoreum, demonstrating the polyethylene toxicity microplastic-ciprofloxacin-Cu2+ complex was mainly caused by Cu2+ and ciprofloxacin rather than microplastics. This study provides theoretical support for the environmental behavior and ecological effects of microplastics in aqueous environments.

Physiological response of ectomycorrhizal fungi (Lactarius delicious) to microplastics stress

<p>The pollution and toxicological effects of microplastics in soil have gradually attracted widespread attention, but studies on the ecological effects of microplastics on soil microorganisms and their mechanisms are still very scarce. To explore the physiological response of ectomycorrhizal fungi (Lactarius delicious, Ld) to microplastic stress, Ld was used as the test strain, and 80 nm and 4 μm monodisperse polystyrene microspheres (PS-MPs) were selected. The solid plate method and the liquid culture method were used to study the effect of PS-MPs with two particle sizes on the growth, nutrient content, reactive oxygen species (ROS) production, organic acid secretion and other indicators of the strain Ld. The results showed that with increasing PS-MPs concentration, the biomass of strain Ld decreased gradually. When the strain Ld was exposed to high concentrations of PS-MPs (200-300 mg L-1), PS-MPs with particle size of 4 μm showed stronger inhibition of biomass than PS-MPs with particle size of 80 nm. After exposure to the PS-MPs environment of two sizes, the concentration of PS-MPs increased (0-300 mg L-1), and the contents of phosphorus (P), potassium (K), H2O2 and superoxide anion radical (O2·-) in Ld mycelia increased significantly (p < 0.05). This showed that the antioxidant substances in Ld could not remove excess ROS, but could reduce the stress of microplastics by increasing the absorption of P and K from the environment, which was beneficial to its own metabolic activities. In addition, the strain Ld could secrete oxalic acid, acetic acid and succinic acid into the culture medium, which the amount of oxalic acid secreted was the highest. We speculated that strain Ld responded to the stress of microplastics by secreting a large amount of organic acids. Therefore, the mechanism of the influence of microplastics on ectomycorrhizal fungi may involve oxidative stress, and the mycelia responded to the toxicity of microplastics by secreting more organic acids and increasing the absorption of P and K. The results of this study will provide a scientific basis for the study of the acute toxicity of microplastics to ectomycorrhizal fungi.</p>

Source and Route of Microplastics in Terrestrial, Atmospheric, and Aquatic Environments, and Effects of Microplastics on Organisms

Objectives : Microplastics, known as pieces of polymer debris less than 5 mm, result from plastic particles originally manufactured to small size or fragmentation from larger plastic items. Due to the persistence, microplastics can remain and accumulate in land and ocean for a prolonged period. Microplastics enter ecosystems and cause various problems. Trophic transfer of microplastics can be occurred in food chain, accordingly humans also can ingest microplastics. The accumulation of microplastics raises concerns regarding impacts on human health and terrestrial and aquatic ecosystems. Here, we discuss the source and route of microplastics found in environments, and ecological effects of microplastics on organisms.Methods : We explore how microplastics enter terrestrial, atmospheric, and aquatic environments and influence individual animals, plants, and microorganisms living in diverse ecosystems. Research literature is reviewed microplastics in terms of ecological risk published between 2010s and June 2022.Results and Discussion : Diverse human activities (e.g., industrial and agricultural activity) accelerate the production of microplastics and result in a release of microplastics to surrounding ecosystems. The microplastics can circulate among the terrestrial, atmospheric, and aquatic environments. The exposure of microplastics can induce oxidative stress, damage of intestinal cells, and reduce the body size in animals. In plants, length of root, biomass, and chlorophyll content are decreased upon exposure to microplastics. In addition, microplastics inhibit the growth of microalgae by reducing algal chlorophyll contents and cause oxidative stress.Conclusion : This paper includes basic information regarding the occurrence and accumulation of microplastics and their ecological effects on organisms. The contents will help to understand behavior of microplastics in diverse environments and to further evaluate ecological impacts of microplastics.

Ecological effects of microplastics on microorganism characteristics in sediments of the Daihai Lakeshore, China

Microplastics are contaminants of emerging concern. In particular, research on the ecological effects of microplastics on microorganisms has attracted widespread attention. In this study, the role of characteristics of microplastics and environmental factors on microorganisms in sediments along the Daihai Lakeshore were investigated. Microscopic identification of microplastics revealed that the most common characteristics of microplastics were fiber, black color and particle size <0.5 mm. The results of Pearson correlation analysis verified that the characteristics of microplastics with particle size <0.5 mm and the main physicochemical characteristics of the sediments (pH, salinity) were positively correlated with the abundance of dominant microorganisms (P < 0.05). In addition, Kyoto Encyclopedia of Genes and Genomes (KEGG) functional pathway analysis that the proportion of functional metabolic pathways related to DNA replication, recombination and reparation was higher in the sampling sites with higher microplastics abundance. This study will provide valuable information for assessing the microbial ecological effects of microplastics contamination in sediments.

The distribution and ecological effects of microplastics in an estuarine ecosystem

Coastal sediments, where microplastics (MPs) accumulate, support benthic microalgae (BMA) that contribute to ecosystem functions such as primary production, nutrient recycling and sediment biostabilization. The potential interactions between MPs, BMA and associated properties and functions remain poorly understood. To examine these interactions, a survey of 22 intertidal sites was conducted. MP abundance, size and a suite of MP diversity indices (based on color and shape) were determined from surface sediments alongside biochemical and physical properties. MPs were detected at all sites and dominated by polypropylene (34%), polyester (18%) and polyethylene (11%). Fragment and fiber dominance (16–92% and 6–81% respectively) and color-shape category diversity varied significantly by site. Distance-based linear models demonstrated that estuary-wide, mean grain size and mud were the best predictors of MP abundance-diversity matrices, but variance explained was low (9%). Relationships were improved when the data was split into sandy and muddy habitats. In sandy habitats (<8% mud), physical properties of the bed (mean grain size, mud content and distance from the estuary mouth) were still selected as predictors of MP abundance-diversity (14% variance explained); but a number of bivariate relationships were detected with biochemical properties such as BMA associated pigments and organic matter. In muddy habitats (>8% mud), porewater ammonium was lower when fiber abundance and overall MP diversity were higher. The inclusion of porewater ammonium, organic matter content and pheophytins alongside physical properties explained a greater percentage of the variance in MP abundance-diversity for muddy habitats (21%). The results highlight the importance of examining plastic shapes and MP categories in addition to abundance and emphasize that functionally different habitats should be examined separately to increase our understanding of MP-biota-function relationships.

Quantification and Analysis of Microplastics in Farmland Soils: Characterization, Sources, and Pathways

While microplastics (MPs) have been identified extensively in aquatic ecosystems, their presence remains largely unexplored in soil ecosystems. Considering the potential effect of MPs on soil biodiversity and function, the present study investigated and analyzed the abundance and characteristics of MPs in soil profile. Taking soil samples from Tainan city farms, as one of the hotspots of agricultural practices in Taiwan, concentrations, types, compositions, pathways, and sources of MPs in farmland soils were quantified. Results showed that MPs were found in all soil samples in different depths ranging from 12–117 items/m2 and MP abundance in farms adjacent to the suburban roads was about three times more than in enclosed farms separated from roads. Fragment and fibers were the main forms and low-density polyethylene was the dominant polymer of detected MPs. Historical land use, extensive application of plastic mulch, and utilization of fruit protection foams were identified as the main sources of MPs in farmlands. This study identifies the presence of MP emissions in farmland soils and investigates its features, which could serve as a framework for future studies into the ecological effects of MPs in the terrestrial environment.

Airborne Microplastics: A Review on the Occurrence, Migration and Risks to Humans.

As emerging environmental contaminants, microplastics may cause potential hazard to global ecosphere (including water, soil and air) and human health. To date, the occurance and ecological effects of microplastics in water and soil were systematically summarized. However, there are few reviews of microplastics in air (i.e. airborne microplastics). Recently, microplastics have been observed in atmospheric fallout collected from some areas. Although the studies are limited, most of the researches showed that synthetic textiles are the main source of airborne microplastics, and fibers are the dominant shape. Airborne microplastics are contributors to microplastic pollution in aquatic and soil environments. In addition, airborne microplastics can be directly inhaled and posed health risks to humans. Therefore, this review summarized the current knowledge and provide insights into further research to better understand airborne microplastics and their risks to human.

A critical review of microplastic pollution in urban freshwater environments and legislative progress in China: Recommendations and insights

Freshwater systems are vitally important, supporting diversity and providing a range of ecosystem services. In China, rapid urbanization (over 800 million urban population) has led to multiple anthropogenic pressures that threaten urban freshwater environments. Microplastics (<5 mm) result from intensive production and use of plastic materials, but their effects in urban freshwater environments remain poorly understood. Rising concerns over the ecological effects of microplastics have resulted in increased attention being given to this contaminant in Chinese freshwater systems. Some studies provide quantitative data on contamination loads, but in general relevant knowledge in freshwater environment remains narrow in China, and lacking adequate understanding of threshold levels for detrimental effects. Notably, non-standardized sample collection and processing techniques for point and non-point sources have hindered comparisons of contamination loads and associated risk. Meanwhile, legislative frameworks for managing microplastics in China remain in their infancy. This manuscript critically reviews what is known of the nature and magnitude of microplastic pollution in Chinese freshwater environments, and summarizes relevant Chinese legislation. It provides recommendations for improving the legislative framework in China and identifies research gaps that need to be addressed to improve management and regulatory strategies for dealing with microplastic pollution in Chinese urban freshwater environments.

Transport behavior of micro polyethylene particles in saturated quartz sand: Impacts of input concentration and physicochemical factors

The long-term contamination of soil by microplastics may pose risks that are often still not well understood, and the ecological effects of microplastics are mainly dependent on their environmental behavior in environments. This study used saturated quartz sand as a solid porous medium to study the migration and influencing factors of 40–48 μm polyethylene (PE) particles in saturated porous media. The breakthrough curves at different injection concentrations (0.3, 0.4, 0.5 mg/L), flow rates (1.0, 1.5, 2.0, 2.5 ml/L), porous medium particle sizes (1–2, 2–4 mm), ionic strengths (0, 0.01, 0.05 mol/L) and concentrations of fulvic acid (FA) (0, 5, 10 mg/L) were compared and analyzed. The Derjaguin-Landau-Verwey-Overbeek (DLVO) theory was used to more accurately explain relevant transport behaviors. The results showed that the input concentration, flow rate, and particle size can affect the migration of PE particles individually or in combination. As ionic strength increased, the repulsion between microplastics and quartz sand gradually disappeared according to DLVO theory, and their attraction gradually strengthened. As a result, fewer microplastics could penetrate the sand column and reach the water body. With the continuous addition of FA, the repulsive energy between microplastics and quartz sand rose from DLVO theory, and the migration ability of microplastics initially increased before becoming stable because of the effect of straining. In all cases, the migration ability of PE was low (C/C0 < 0.35), and most PE particles remained in the porous media during the whole experimental periods. This study provides new insights of understanding the migration of microplastics in environment.

Ecological Effects of Soil Microplastic Pollution

As a new type of environmental pollutant, microplastics pose a serious threat to soil ecosystems. We reviewed the classification and source of soil microplastics, separation, detection methods and existing problems. The pollution of soil microplastics and the adsorption effect and mechanism of microplastics on pollutants are summarized. The effects on soil animals, microbial ecology and carbon, nitrogen and other material cycles were analyzed. Furthermore, the ecological effects of microplastics are proposed, which provides new ideas for the study of soil microplastics in the future.

Polystyrene microplastics cause tissue damages, sex-specific reproductive disruption and transgenerational effects in marine medaka (Oryzias melastigma)

The ubiquity of microplastics in the world's ocean has aroused great concern. However, the ecological effects of microplastics at environmentally realistic concentrations are unclear. Here we showed that exposure of marine medaka (Oryzias melastigma) to environmentally relevant concentrations of 10 μm polystyrene microplastics for 60 days not only led to microplastic accumulation in the gill, intestine, and liver, but also caused oxidative stress and histological changes. Moreover, 2, 20, and 200 μg/L microplastics delayed gonad maturation and decreased the fecundity of female fish. Alterations of the hypothalamus-pituitary-gonadal (HPG) axis were investigated to reveal the underlying mechanisms, and gene transcription analysis showed that microplastic exposure had significantly negative regulatory effects in female HPG axis. Transcription of genes involved in the steroidogenesis pathway in females were also downregulated. This disruption resulted in decreased concentrations of 17β-estradiol (E2) and testosterone (T) in female plasma. Furthermore, parental exposure to 20 μg/L microplastics postponed the incubation time and decreased the hatching rate, heart rate, and body length of the offspring. Overall, the present study demonstrated for the first time that environmentally relevant concentrations of microplastics had adverse effects on the reproduction of marine medaka and might pose a potential threat to marine fish populations.

Environmental processes and ecological effects of microplastics in the ocean

There are no doubts that plastics problem in the ocean environment has become an increasingly worldwide focus in past several decades. A number of experts regard the plastic wastes as one of the hardest anthropogenic threats. The degraded items of large individual plastics lead to millions of microplstics (MPs) ultimately. As a result, the new pollution has appeared in the ocean. The ever-growing MPs have been detected in subtotal sea products, such as sea food and table salts. The MPs can bring potential health risk to people by enrichment in sea products. Furthermore, the economic development of offshore fishery and the marine tourism have been inhibited badly. This article will make a brief review on present studies about MPs in the ocean.

Microplastics in the intestinal tracts of East Asian finless porpoises (Neophocaena asiaeorientalis sunameri) from Yellow Sea and Bohai Sea of China

The direct evidences for the ingestion of microplastics by cetaceans, especially the cetaceans in Asian marine areas are limited. In this study, residue of microplastics in the intestinal tracts of East Asian finless porpoises (Neophocaena asiaeorientalis sunameri) was investigated. Microplastics were detected in all specimens, with mean abundance of 19.1 ± 7.2 items/individual. With respect to microplastics properties, fibers, blue items, and polypropylene were predominant in shapes, colors, and plastic materials, respectively. Trophic transfer and unintentional ingestion might be the potential pathways for microplastics ingested by finless porpoise. The specific intestinal structure might account for the predominance of fibers and the accumulation of microplastics at the beginning portion of intestines. This study indicates that cetaceans in Chinese marine areas also suffer from microplastics pollution. Further studies on the fate and ecological effects of microplastics should be conducted to reveal their potential risks to cetaceans.

Polystyrene microplastics alter the behavior, energy reserve and nutritional composition of marine jacopever (Sebastes schlegelii).

Uptake and toxicity of microplastics on marine organisms have been reported elsewhere. However, there is limited knowledge regarding the ecological effects of microplastics on marine organisms. In this study, we investigated the effects of polystyrene microplastics (1 × 106 microspheres per L) on the behavior, energy reserve and nutritional composition of juvenile jacopever (Sebastes schlegelii). Compared to the controls, fish treated by microplastics showed lower sensitivity toward the added food in the tank, and increased foraging time, indicating that microplastics significantly weakened feeding activity of the fish. Interestingly, the microplastics treated-fish obviously reduced swimming speed and range of movement, demonstrating that polystyrene microplastics could have negative effect on hunting behavior. Furthermore, polystyrene microplastics accumulated in the gills and intestine, causing significant histopathological changes in the gallbladder and liver. Moreover, the energy reserve and nutritional quality of fish were influenced by microplastics as evidenced by lower growth, protein and lipid contents. Our results highlighted the potential negative effects of microplastics on marine ecological function and food safety.