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Polyethylene (PE) is a common component of microplastic pollution, and cadmium (Cd) is a prevalent pollutant in contaminated freshwater bodies in China. Among cyanobacteria, Microcystis aeruginosa (M. aeruginosa) plays a crucial role in the formation of algal blooms in these water systems. However, there has been limited research on how microplastics and heavy metals affect cyanobacteria ecologically. This study aimed to evaluate the physiological effects of individual and combined exposure to Cd pollutants and microplastics on M. aeruginosa. The solutions containing 13 µm and 6.5 µm PE particles (100 mg/L) with Cd were used in the research. The results indicated that the combined treatment led to a significant inhibition of chlorophyll a content, dropping to zero by day 5. The treated groups exhibited higher microcystins (MCs) content compared to the control group, suggesting increased MCs release due to pollutant exposure. Interestingly, the adsorption of heavy metals by microplastics partially alleviated the toxicity of heavy metals on algal cells. Moreover, the combined treatment significantly suppressed catalase (CAT) activity compared to Cd treatment, indicating a synergistic effect that led to greater oxidative stress. Overall, this study provides valuable insights into the impact of PE and Cd pollution on freshwater ecosystems, elucidates the physiological responses of cyanobacteria to these pollutants, and establishes a theoretical groundwork for addressing complex water pollution using cyanobacteria-based strategies. [ABSTRACT FROM AUTHOR]

Polymer-blend High Density Polyethylene (PHDPE) sheet materials have been developed in China as an alternative to the High Density Polyethylene (HDPE) materials for the manufacture of geocells. It is necessary to evaluate the creep properties of the geocell-reinforced structures to provide a reference for design of their service life and improve their application potential. In this paper, the Stepwise Isothermal Method (SIM) based accelerated creep testing, in which the test temperature was gradually increased but the load was kept constant, was employed obtain the long-term creep behavior of PHDPE and HDPE geocell sheets. Conventional creep tests were also carried out to assess the accuracy of the creep prediction. Furthermore, the Modified Burgers (MB) model and the Mon-linear Three-component (NLTC) model were proposed to predict long-term creep deformations of the PHDPE geocell sheets. The experimental results indicated that SIM creep tests could predict long-term creep deformations. The creep resistance of all three PHDPE, PHDPE-A, PHDPE-B, and PHDPE-C, was better than that of HDPE due to the addition of nylon 6 for the polymer-blending modification in HDPE. Comparison of the experimental data with the predicted data also confirmed that the MB and NLTC models could accurately model the viscoelastic-plastic creep behavior of PHDPE geocell sheets. • The creep behavior of polymer-blend geocells was investigated by conducting the accelerated creep test. • The comparison of creep resistance of polymer-blend geocells and high-density polyethylene geocells was presented in this study. • The predicted accuracy and suitability of the stepped isothermal method were verified in this study. • Two viscoelastic-plastic models were proposed to predict the long-term creep deformation of polymer-blend geocells. [ABSTRACT FROM AUTHOR]

Anthracnose, a disease primarily caused by the fungus Colletotrichum sublineola, affects sorghum production in China. However, the infection mechanisms and complex host interactions of C. sublineola remain to be elucidated. Thus, this study aimed to establish and optimize a protoplast transformation system of C. sublineola so as to lay a foundation for further research on the infection mechanisms and complex host interactions of C. sublineola. A genetic transformation system was established and optimized for C. sublineola strain HX‐5‐1 and used to introduce fluorescent reporter genes, namely, green fluorescent protein (GFP) and mCherry. Results showed that the growth of HX‐5‐1 was completely inhibited on a regenerating medium containing 300 μg mL−1 hygromycin B, indicating that hygromycin B acted as a transformant‐selective marker. HX‐5‐1 produced the highest yield of protoplasts when the mycelia were cultured for 60 h and dissolved in a 0.1% lysozyme solution (0.7 M NaCl) for 3 h. Subsequently, a 106 mL−1 protoplast solution transformed using 5 μg of plasmid DNA exhibited the highest transformation efficiency. Laser confocal microscopy showed that GFP and mCherry fluorescent signals were successfully expressed in the mycelia and spores of HX‐5‐1, indicating that they were stably inherited in the transformants and did not affect colony morphology, growth rate, or pathogenicity. In conclusion, we successfully established a genetic transformation system for C. sublineola and employed it to obtain stable fluorescent protein expression. This study may serve as a foundation for understanding the infection process of C. sublineola. [ABSTRACT FROM AUTHOR]

[Display omitted] • The first overview of co-authorship network of microplastics in landfill leachate. • Light color Polyethylene, Polypropylene, and Polystyrene are dominant in leachate. • Microplastics abundance is biased with different sampling and analysis techniques. • There are no global standards for microplastic management. Plastic wastes deposited in landfills eventually break down and degrade into microplastics by physical, chemical, and biological forces. Though microplastics in leachate pose significant threats to the environment, the leachate generated from landfills has not received much attention as a possible source of environmental microplastics. A descriptive and systematic investigation of the global distribution of microplastics in landfill leachate does not exist to date. Therefore, this attempt is to provide a concise scientometric review of the studies on the presence of microplastics in landfill leachate. The present review revealed that the global trend in research on microplastics in leachate has increased exponentially after 2018 and China is the leading country. Different geographical regions have reported different microplastic abundances with the highest of 291.0 ± 91.0 items/L from a landfill in Shanghai. The use of novel sampling techniques to detect small microplastics (20–100 µm) has led to the high abundance of microplastics in landfill leachate in Shanghai. Due to its widespread usage, polyethylene is the most typically encountered polymer type in landfill leachate around the world. However, it is quite challenging to compare the results among studies due to the use of different size categories and extraction techniques. The removal of microplastics by the current leachate treatment facilities is still mostly unexplored, thus it is crucial to develop novel technologies to treat the microplastics in landfill leachate. Further investigations on the transport of microplastics in landfill leachate are urgently required to have a better understanding of potential human exposure and health implications. [ABSTRACT FROM AUTHOR]

Optical cable is an important part of modern telecommunications infrastructure. In this study, cone calorimeter experiments are conducted on the optical cables which are widely being applied in utility tunnels in China. The coupling effect of the spacing between optical cables (8, 10, 12, 15 mm) and the heat flux (30, 40, 50 kW/m2) on fire performance of optical cables is studied. It is highlighted that the optical cables conform to the ignition time model of the thermally thin material. The ignition time of the optical cables decreases when increasing the heat flux. When the heat flux is 30 kW/m2, the ignition time of the optical cable with different spacing varies greatly. When the heat flux is greater than 30 kW/m2, the difference in the ignition time between the optical cable samples with different spacing is small. Furthermore, the average mass loss rate of the optical cables increases when increasing either the heat flux or the spacing between optical cables. The heat release rate of the optical cables also increases when increasing either the heat flux or the spacing between optical cables. The curves of the heat release rate versus time show two peaks, the second one being significantly smaller. [ABSTRACT FROM AUTHOR]

Xinjiang is in northwest China and has abundant desert sand. Replacing natural sand with sand from deserts is an urgent need and could be used in making polyethylene fiber−engineered cementitious composite (PE−ECC). The interfacial bonding properties of desert sand PE−ECC (DSPE−ECC) were made using the optimal mix proportion (30% desert sand content, 2% fiber volume) and the laboratory's previous research results. Normal sand PE−ECC (NSPE−ECC) and DSPE−ECC at different test ages (3, 7, 14, and 28 days) were subjected to uniaxial tensile tests, and a method for determining bonding properties is proposed. Scanning electron microscopy and X-ray diffraction were used to analyze the development of PE−ECC fiber and matrix and the formation of hydration products. The results indicated that the cracking loads of the DSPE−ECC at 3, 7, 14, and 28 days increased by 16.72%, 28%, 23.23%, and 10.05%, respectively. Desert sand had low water content and high water absorption, which slowed down the rate of C2S, C3S combining with water molecules to form C−S−H, and had a great influence on the bonding properties of ECC at 3 days. However, the bonding properties of DSPE−ECC were only slightly less than those of NSPE−ECC at 28 days, and the bonding properties had gradually stabilized. Therefore, the addition of desert sand enhanced the fiber/matrix's bonding properties, and the bonding properties stablized with the increase in curing ages. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) and heavy metals (HMs) co-exist in sweet potato fields of China. As the main component of agricultural field mulch and one of the most polluting and harmful HMs, the effects of polyethylene microplastics (PE MPs) and cadmium (Cd) on sweet potato and soil environment are remains unclear. Here, pot and hydroponic experiments are used to explore the effects of original and weathered PE MPs on growth and Cd uptake of sweet potatoes. The results of pot experiments reveal that compared with the control (0%), 5% of weathered PE MPs can significantly increase soil electrical conductivity (EC); both 5% of the original PE MPs and weathered PE MPs can significantly reduce the concentration of Olsen phosphorus (P) and Olsen potassium (K) in soil, inhibit plant growth, but significantly increase Cd accumulation and glutathione (GSH) level in tissues of sweet potatoes, and also induce membrane lipid peroxidation. In addition, compared to 5% weathered PE MPs, 5% original PE MPs significantly reduce soil EC, growth and peroxidase level of sweet potatoes, but significantly increase Cd concentration in leaves and stems. The results of hydroponic experiment show that original PE MPs significantly increase the P, K, and Cd adsorption compared with weathered PE MPs, and Cd increases the original PE MPs accumulation in the root cortex but decrease PE MPs accumulation in shoots. To sum up, our study investigates the differences and reasons of the effects of original and weathered PE MPs on growth and Cd absorption of sweet potatoes. [ABSTRACT FROM AUTHOR]

Licorice (Glycyrrhiza uralensis Fisch.) is the most widely used botanical medicine in China, an annual demand of 60 thousand tons leads to wild resources failing to meet medicinal needs and the cultivation becoming popular. The environment and the secondary metabolites of plants are closely negatively related, and the quality of cultivated herbs under better conditions reduces seriously and even fails to meet the standard of Chinese pharmacopeia. Drought is the most important factor affecting the quality of licorice. Drought was created by soaking the fresh roots of G. uralensis with polyethylene glycol-6000 (PEG), the superoxide radical, hydrogen peroxide, nitric oxide, and malondialdehyde significantly increased, indicating that the plant cells suffered oxidative damage. The superoxide dismutase, catalase, and peroxidase showed a downward trend in the 6th to 8th days, signifying that excessive reactive oxygen species (ROS) can injure the antioxidase system and low ability to scavenge ROS, a characteristic of adversity stress. But the secondary metabolism was enhanced through rising the 1,3-bisphosphoglycerate, phosphoenolpyruvate carboxylase, and enzymes related to the secondary metabolic pathway, such as phenylalanine ammonia-lyase, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, squalene synthase, and β-amyrin synthase, with a result in boosting biosynthesis of flavonoids and triterpenoids. With 5% PEG, the liquiritin, isoliquiritin, liquiritin apioside, isoliquiritin apioside, liquiritigenin, isoliquiritigenin, echinatin, licochalcone B, glycyrrhizic acid, and glycyrrhetinic acid heightened by 48.3, 61.2, 35.3, 50.3, 75.9, 72.6, 60.8, 44.6, 63.8, and 55.1%, respectively, and solve the problem of the quality decline of cultivated licorice. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) pollution in freshwater poses a risk to various ecosystems and health security. In 2018, the Chinese government banned fishing since 2018 in the Three Gorges Reservoir (TGR), but the fate and risk of MPs in wild fish remain unclear. Therefore, a detailed investigation was conducted into the occurrence of MPs in 18 wild fish species in the TGR using a Micro Fourier Transform Infrared Spectrometer, and the trophic transfer and risks were assessed. MPs in fish were aged, with abundances ranging from 0.68 ± 0.98 to 4.00 ± 2.12 items/individual. Most particles were less than 1 mm in size (73.4 %), with fibers being the dominant shape (48.9 %) and transparent as the dominant color (35 %). Polyethylene (PE) was the most prevalent type. The bioconcentration factor (BCF), bioaccumulation factor (BAF), trophic magnification factor (TMF) and polymer hazard index (PHI) were low, suggesting no trophic transfer and a low risk of MPs. The BAF may provide a more reasonable description of the degree of enrichment of MPs, and 'items/individual' or 'g/individual' can be used to describe MPs concentrations in fish. This study proposes new insights and prospectives that can help researchers better understand MPs enrichment in fish across various trophic levels., Competing Interests: Declaration of Competing Interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Biodegradable polylactic acid (PLA) mulch has been developed to replace conventional polyethylene (PE) mulch in agriculture as a response to growing concerns about recalcitrant plastic pollution and the accumulation of microplastics (MPs) in soil. Cadmium is a significant soil pollutant in China. MPs have been shown to adsorb metals. In this study the earthworm Lumbricus terrestris was exposed to either Cd (1.0-100 mg / kg) or MPs (PE and PLA, 0.1-3 % w / w), or a combination of the two, for 28 days. Cd bioavailability significantly decreased in the presence of MPs. In particular, at the end of the experiment, PLA treatments had lower measured Cd concentrations in both earthworms (2.127-29.24 mg / kg) and pore water (below detection limits - 0.1384 mg /L) relative to PE treatments (2.720-33.77 mg / kg and below detection limits - 0.2489 mg / L). In our adsorption experiment PLA MPs adsorbed significantly more Cd than PE MPs with maximum adsorption capacities of 126.0 and 23.2 mg / kg respectively. These results suggest that the PLA MPs reduce earthworm exposure to Cd relative to PE by removing it from solution and reducing its bioavailability., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Xiao Xiao reports financial support was provided by China Scholarship Council. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Subsurface organic ameliorant plus polyethylene mulching is a novel strategy for saline soil improvement and utilization in China. However, little is known about how this strategy impacts soil organic carbon (SOC) both directly (carbon input) and indirectly (soil aggregates protection and microbial regulation). Therefore, a field experiment was arranged and sampled after 3 years, including four treatments, i.e., no ameliorant with and without polyethylene mulching, and subsurface (10–30 cm soil depth) organic ameliorant with and without polyethylene mulching. Subsurface organic ameliorant raised the SOC content in the 0–40 cm by 70% and 90% with and without mulching, respectively. Subsurface organic ameliorant converted the major aggregation size from <0.053 to 0.25–2 mm, indicating that both direct carbon (C) input and indirect soil aggregates protection contributed to the increase in SOC content. In contrast, polyethylene mulching reduced the SOC content by 16% and 6% with and without organic ameliorant respectively. This was due to lower fungal diversity by 9%–14% and supported by the positive effect from fungal diversity to SOC. Further, the subsurface organic ameliorant plus polyethylene mulching increased SOC by 61% through direct C input, indirect soil aggregates protection and microbial regulation. Meanwhile, the contribution of physical protection standardized total effect (STE) = 0.223–0.294] was higher than microbial regulation (STE = 0.040–0.162) according to a structural equation model. Consequently, subsurface organic ameliorant plus polyethylene mulching represents a feasible agricultural practice to increase the SOC content for saline soil amelioration. [ABSTRACT FROM AUTHOR]

As an important part of a double-layer shaft lining in China, a polyethylene sandwich can reduce or even eliminate the constraint effect on the inner shaft lining, which is confined by the outer shaft lining, thus improving the integrity of the inner shaft lining concrete. To reveal the interface shear mechanism of the concrete-high density polyethylene (HDPE) material, a series of 16 direct shear tests were performed under high normal loads (0.6~4 MPa) with four different surface morphologies. The experimental results showed that the interfaces exhibit a clear strain-softening property during shear, and the shear strength increases linearly with increasing normal stress. Three shearing mechanisms, plowing, localized plastic deformation, and dilatancy, were observed in these experiments. The research results are of great theoretical and practical value for understanding the shear mechanism and predicting the shear strength of a shaft lining concrete-HDPE interface under high normal stress. [ABSTRACT FROM AUTHOR]

With the rapid development of planting techniques using plastic film mulching, the content of residual plastic film in soil increases year by year, which pollutes the soil and water, endangers the growth of crops and reduces the quality and yield of agricultural products. Therefore, in order to solve the problem that plastic film with a thickness of 0.008 mm, commonly used in China, is difficult to recycle, this study designed the residue film recycling machine based on the existing research results. After harvesting cotton in Xinjiang, the working performance of the residue film recovery machine of plough layer was measured. Through theoretical optimization and field experiments, the effects of conveyor speed, distance between elastic teeth and type of elastic teeth on residual film recovery were studied. The relationship between the parameters of the residual film recovery machine and the recovery effect of the residual film was analyzed. When the rotational speed and inclination angle of the conveying and separating device were 74 rpm, 35° and 120 rpm, 45°, respectively, under the condition that the distance between C-shaped elastic teeth was 59 mm, the recovery and separation rate of residual plastic film were 88.12% and 83.27%, respectively. Based on the study results, it is recommended to accelerate the development of naturally degradable agricultural plastic film or to popularize and apply thickened film. Relevant local standards and policies have been formulated to address the problem of residual film pollution, and a governance system has been established for the benefit of the government, scientific research institutions, enterprises and farmers. This study provides a reference for mechanized recovery of residual plastic film in soil and treatment of soil pollution. [ABSTRACT FROM AUTHOR]

In the agricultural lands of China, polyethylene is the main component of microplastics （MPs）, with characteristics such as small size, wide distribution, easy accumulation, and difficult degradation. Therefore, it may have an impact on the elemental cycling process of the soil. On the basis of reviewing the key literatures in the past few years, this study systematically analyzed and summarized the key factors and processes of the polyethylene microplastics （PE-MPs） affecting soil nitrogen transformation. On the one hand, PE-MPs directly affected the activities of microorganisms and key enzymes related to soil nitrogen transformation by enriching microorganisms, selecting colonized microbial populations, and releasing additives. On the other hand, PE-MPs had indirect impacts on the activities of microorganisms and key enzymes related to soil nitrogen transformation by affecting soil physicochemical properties of soil and changing the microenvironment for microbial growth. Moreover, phthalates, an important additive of the MPs, may be the key factor affecting soil nitrogen transformation in the short-term. Finally, we posed key scientific issues that should be further studied in order to provide scientific support for nitrogen nutrition regulation and ecological risk assessment of soils contaminated by PE-MPs.

As an emerging pollutant, microplastics (MPs) cause widespread concern around the world owing to the serious threat they pose to ecosystems. In particular, sediments are thought to be the long-term sink for the continual accumulation of MPs in freshwater ecosystems. Polyethylene (PE) and polyethylene terephthalate (PET) have been frequently detected with large concentration variations in freshwater sediments from the lower reaches of the Yangtze River, one of the most economically developed regions in China, characterized by accelerated urbanization and industrialization, high population density and high plastics consumption. However, the impact of PE and PET on the sedimental bacterial community composition and its function has not been well reported for this specific region. Herein, PE and PET particles were added to freshwater sediments to assess the effects of different MP types on the bacterial community and its function, using three concentrations (500, 1500 and 2500 items/kg) per MP and incubations of 35, 105 and 175 days, respectively. This study identified a total of 68 phyla, 211 classes, 518 orders, 853 families and 1745 genera. Specifically, Proteobacteria, Chloroflexi, Acidobacteriota, Actinobacteriota and Firmicutes were the top five phyla. A higher bacterial diversity was obtained in control sediments than in the MP-treated sediments. The presence of MPs, whether PET or PE, had significant impact on the bacterial diversity, community structure and community composition. PICRUSt2 and FAPOTAX predictions demonstrated that MPs could potentially affect the metabolic pathways and ecologically functional groups of bacteria in the sediment. Besides the MP-related factors, such as the type, concentration and incubation time, the physicochemical parameters had an effect on the structure and function of the bacterial community in the freshwater sediment. Taken together, this study provides useful information for further understanding how MPs affect bacterial communities in the freshwater sediment of the lower reaches of the Yangtze River, China., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Microplastic pollution in the soil environment is of great concern. However, the current research on microplastics (MPs) in Southwest China mainly focuses on their distribution characteristics and sources in soil, making the understanding of the soil properties and land use patterns influencing soil MPs insufficient. In this study, the abundance and distribution characteristics of MPs in the soil of different land use patterns in Guizhou Province were determined. The results revealed that the average abundance of MPs in soils was 2936 items/kg, ranging from 780 to 9420 items/kg. The MPs were mainly small particle size (0-0.5 mm), granular, and black, accounting for 87.5%, 36.6%, and 82.2%, respectively. The most common polymer types of MPs were polypropylene, polyethylene terephthalate, and polyethylene, which accounted for 20.4%, 16.8%, and 16.4%, respectively. As soil bulk density increased, microplastic abundance and small particle size decreased. Soil microplastic abundance slightly decreased with increasing soil porosity. The abundance of MPs increased with the increase in soil pH, but no significant correlation was observed between soil organic matter content and microplastic abundance. pH was the major factor that affected the microplastic distribution, which accounted for 32.5%. This study provides insight into the distribution and influencing factors of soil MPs and also provides a theoretical basis for subsequent research on soil microplastic pollution., Competing Interests: Declaration of competing interest The authors declare that they have no know competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The widespread presence of microplastics (MPs) contamination in drinking water has raised concerns regarding water safety and public health. In this study, a micro-Raman spectrometer was used to trace the occurrence of MP transport from a water source to a drinking water treatment plant (DWTP)1 with an advanced treatment process and DWTP2 with a conventional treatment process and the contributions of different processes to the risk reduction of MPs were explored. Six types of MPs were detected: polyethylene terephthalate, polyethylene, polypropylene, polystyrene, polyamide, and polyvinyl chloride. 2-5 μm (35.8-41.2%) and polyethylene terephthalate (27.1-29.9%) were the most frequently detected MP sizes and types of water source samples, respectively. The abundance of MPs in treated water decreased by 72.7-83.0% compared to raw water. Ozonation and granular activated carbon (52.7%), and sand filtration (47.5%) were the most effective processes for removing MPs from DWTP1 and DWTP2, respectively. Both DWTPs showed significant removal effects on polyethylene terephthalate, with 80.0-88.1% removal rates. The concentrations of polystyrene increase by 30.0-53.4% after chlorination. The dominant components in the treated water of DWTP1 and DWTP2 were polypropylene (24.7%) and polyethylene 27.7%, respectively, and MPs of 2-5 μm had the highest proportion (55.3-64.3%). Pollution load index and potential ecological risk index of raw water treated by DWTPs were reduced by 48.0-58.7% and 94.5-94.7%, respectively. The estimated daily intake of MPs in treated water for infants was 45.5-75.0 items/kg/d, respectively, approximately twice that of adults. This study contributes to the knowledge gap regarding MP pollution in drinking water systems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Light stabilizers are commonly used as additives in mulching films and have environmental persistence, bioaccumulation and ecotoxicity. However, their occurrence and distribution in mulching films and accumulation in mulched soils are seldom reported. This study firstly presents a comprehensive screening of 19 light stabilizers in 65 mulching films and 30 farmland soils collected in China, of which five and eight light stabilizers were 100% detected, respectively. The light stabilizer concentration in biodegradable mulching films was significantly higher than that in polyethylene ones, with median concentrations of 1.75 × 10 6 μg/kg and 4.86 × 10 3 μg/kg, respectively. Furthermore, a positive correlation was observed between the light stabilizer concentration in mulching films and in soils. This indicates that mulching films play a critical role in the accumulation of light stabilizers in farmland soils, and biodegradable mulching films significantly increase benzotriazole light stabilizers in soils. Although the light stabilizer concentration in farmland soil is relatively low, the sustainable quantities of mulching film input and the long-term accumulation will still pose a threat to the ecological environment and organism health. Consequently, our work reveals the occurrence and environmental risk of light stabilizers in mulching films and farmland soils and brings attention to light stabilizers in the soil environment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

China's import bans on solid wastes starting from 2017 have challenged the global trade system of plastic wastes, which remains poorly characterized. This study chooses polyethylene (PE) as a case and aims to map out the global trade networks of PE waste (GPETN) from 1976 to 2017. We find that the size and complexity of the GPETN had been growing until 2016. After the mid-1990s, PE waste basically flowed from developed economies, mainly the EU and the US, to developing economies such as China. Since 2001 when admitted into the WTO, China's PE waste import surged until 2014 when it absorbed over 60% of global export. Regulations on solid waste import following the Green Fence campaign in 2013 resulted in substantial reductions in China's import as well as the global export of PE waste after 2014. Several other developing economies, such as Malaysia, Turkey, and Vietnam, had transitioned to net importers, but their imports were insufficient to replace China as new recycling bases for PE waste. The results highlight the urgent need of a joint effort for developed and developing countries to build a stronger global circular economy system with sufficient capacity to treat PE waste locally. [ABSTRACT FROM AUTHOR]

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Rubber vulcanization generates volatile organic compounds emissions associated with the intermolecular crosslinking reactions at rather higher temperatures mediated by many kinds of indispensable additive. To achieve the carbon peaking and neutrality targets in China, rubber processing industries call for ecofriendly, green additives to satisfy demands of high-efficiency vulcanization at low temperatures. Herein an oligomer deep eutectic solvent (DES) based on polyethylene glycol is used for the first time for regulating vulcanization kinetics of natural rubber (NR) gums. It is found that DES at 0.2–1.0 phr (parts per hundred parts of rubber) dosages could accelerate the vulcanization at 120–140 °C without marked influences on crosslinking density and storage modulus at vulcanization equilibrium. The vulcanization of DES-containing gums at 120 °C is faster than that of the DES-free one at 140 °C while the DES-containing vulcanizates cured at 120 °C exhibit nonlinear rheological responses being similar to the DES-free one cured at 140 °C. The low-temperature vulcanization in general generates vulcanizates exhibiting higher tensile strength in comparison with those cured at 140 °C. Furthermore, DES could not influence the Mullins effect of the vulcanizates undergoing cyclic tension deformation. The results show that the non-volatile DES could be used to adjust the vulcanization kinetics without impact on the crosslinking density and Mullins effect, paving the way for developing energy-saving green vulcanization technologies. Polyethylene glycol-based deep eutectic solvent accelerates vulcanization of natural rubber without impact on the crosslinking density, paving the way for developing energy-saving green vulcanization technologies. [Display omitted] • Polyethylene glycol-based deep eutectic solvent (DES) accelerates vulcanization of NR. • DES improves proportion of polysulfide bonds of the crosslinking network. • DES does not influence Mullins effect of the vulcanizates. • DES-containing vulcanizates cured at 120 °C exhibit nonlinear rheology being similar to the DES-free ones cured at 140 °C. [ABSTRACT FROM AUTHOR]

Iron (Fe) plaques in coastal wetlands are widely recognized because of their strong adsorption affinity for natural particles, but their interaction behaviors and mechanisms with plastics remain unknown. Through laboratory incubation experiments, paired with multiple characterization methods and microbial analysis, this work focused on the characteristics of Fe plaques on low-density polyethylene plastic surfaces and their relationship with environmental factors in coastal wetlands (Mangrove and Spartina alterniflora soil). The results showed that iron plaques increased the adhesive force of the plastic surface from 65.25 to 300 nN and promoted the oxidation of the plastic surface. Fe plaque formation was stimulated by salinity, anaerobic conditions, natural organic matter, and a weak alkaline scenario (pH 8.0-8.3). The Fe content showed a stable positive correlation with heavy metals loading (i.e., As, Mn, Co, Cr, Pb, and Zn). Furthermore, we revealed that Fe plaque was positively regulated by Nitrospirae through 16S rRNA high-throughput sequencing analysis. Meanwhile, Verrucomicrobia and Kiritimatiellaeota. may act as depressants by consuming salt. This work illustrated that iron plaques could enhance the role of plastics in contaminant migration by altering their adsorption performance, providing new insights into plastic interface behavior and potential ecological effects in coastal wetlands., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

This research studied the occurrence, risk assessment and metals associated with microplastic (MPs) in soil of different land-use types in the south west of Iran. One hundred samples were collected from topsoil and MPs were extracted using the floatation method. In total, 9258 MPs particles with mean of 92.85 ± 119.24 particles kg -1 were counted. The mean MPs abundance in urban soils was 2.8 and 3.2 times higher than in industrial and agricultural soils, respectively. Fragment (43%) and small MPs (100-250 μm; 41%), were the dominant shape and size, respectively. Four main polymer types including Poly Ethylene (High Density Poly Ethylene and Low Density Poly Ethylene), Nylon (PA), Poly Propylene (PP), and Poly Styrene (PS) were identified. Nylon (29%) and PE (29%) were dominant polymer types. MPs particles in soil contained different levels of metals such as Cd, Cr, Cu, Fe, Hg, Pb, Zn, and Y, except La and Yb. The mean concentrations of metals were higher in MPs than in soil. The indices of MPs-induced risk (H studyarea =16.8) showed a hazard level (III) in the study area. Pollution load index (PLI Landusetype ) showed hazard level (II) for urban soils and hazard level (I) for industrial and agriculture soils, respectively. Overall, risk index indicated high to extreme danger for MPs pollution in the study area. This is the comprehensive study on the occurrence of soil MPs and associated metals, which provides basic information for a further study concerning ecosystem health in Shiraz., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Microplastics and polycyclic aromatic hydrocarbons (PAHs) were investigated to study the influence of human activities and to find their possible relationship on the coastal environments, where the coastal areas around Xiamen are undergoing intensive processes of industrialization and urbanization in the southeast China. The abundance of microplastics in Xiamen coastal areas was 103 to 2017 particles/m 3 in surface seawater and 76 to 333 particles/kg in sediments. Concentrations of dissolved PAHs varied from 18.1 to 248 ng/L in surface seawater. The abundances of microplastics from the Western Harbor in surface seawater and sediments were higher than those from other areas. Foams were dominated in surface seawater samples, however, no foams were found in sediments samples. The microscope selection and FTIR analysis suggested that polyethylene (PE) and polypropylene (PP) were dominant microplastics. The cluster analysis results demonstrated that fibers and granules had the similar sources, and films had considerably correlation with all types of PAHs (3 or 4-ring PAHs and alkylated PAHs). Plastic film mulch from agriculture practice might be a potential source of microplastics in study areas. Results of our study support that river runoff, watershed area, population and urbanization rate influence the distribution of microplastics in estuarine surface water, and the prevalence of microplastic pollution calls for monitoring microplastics at a national scale. [ABSTRACT FROM AUTHOR]

Most of the previous studies of microplastic pollution on coastal habitats focused on high energy beaches although low energy areas such as mudflats are supposed to retain more microplastics, not to mention that mudflats are biologically more diverse. We quantified and characterized microplastics from 10 mudflats and 10 sandy beaches in Hong Kong spanning from the eastern to western waters. Sediment samples were collected at 1.0 m and 1.5 m above chart datum (CD) and at the strandline. Abundance of microplastics ranged between 0.58 and 2116 items kg −1 sediment with that on mudflats being ten times more than on beaches. Polyethylene (46.9%) was the most abundant and followed by polypropylene (13.8%) and polyethylene terephthalate (13.5%). Expanded polystyrene was the most abundant in the strandline samples but not at 1.0 m and 1.5 m above CD. Although previous studies have concluded that the input from Pearl River is a major source of microplastics on Hong Kong shores, this study has demonstrated that the contribution of local pollution sources such as discharge from sewage treatment plants to microplastic pollution should not be neglected. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) have become a major global issue; their release from various products affects the aquatic environment, especially marine ecosystems. As a primary source of MPs, personal care and cosmetics products (PCCPs) containing MPs contribute to this environmental risk. We visited several supermarket chains in Beijing, China to identify PCCPs containing MPs. Overall, 7.1% of facial cleansers contained MPs, with an average weight of 25.04 ± 10.69 mg MP/g and average size of 313 ± 130 μm; whereas, 2.2% of shower gel products contained an average weight of 17.80 ± 7.50 mg MPs/g with an average size of 422 ± 185 μm. The majority of MPs were made of polyethylene, based on Raman and Fourier transform-infrared spectra analyses, while only a few were made of walnut shells and carbon particles. Finally, estimated 39 tons MPs were released into the environment based on PCCPs use in China based on available data. [ABSTRACT FROM AUTHOR]

Plastic film residuals are increasingly remaining in cultivated lands. However, it is a critical issue how residual plastic type and thickness affect soil properties and crop yield. To address this issue, in situ landfill was conducted using thick polyethylene (PEt1), thin polyethylene (PEt2), thick biodegradable (BIOt1), thin biodegradable (BIOt2) residues, and CK (control) with no residues landfill in a semiarid maize field. The findings demonstrated that the impact of various treatments on soil characteristics and maize yield varied considerably. Soil water content decreased by 24.82% in PEt1 and 25.43% in PEt2, compared to BIOt1 and BIOt2, respectively. BIOt2 treatment increased soil bulk density by 1.31 g cm -3 and lowered soil porosity by 51.11%, respectively; it also elevated the silt/clay proportion by 49.42% relative to CK. In contrast, microaggregate composition in PEt2 was higher (43.02%). Moreover, BIOt2 lowered soil nitrate (NO 3 - ) and ammonium (NH 4 + ) content. Compared with other treatments, BIOt2 resulted in significantly higher soil total nitrogen (STN) and lower SOC/STN. Finally, BIOt2 exhibited the lowest water use efficiency (WUE) (20.57 kg ha -1 mm -1 ) and yield (6896 kg ha -1 ) among all the treatments. Therefore, BIO film residues exhibited detrimental impacts on soil quality and maize productivity compared to PE film ones. Considering film thickness, thin residual films more evidently influenced soil quality and maize productivity than thick film ones., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Plastic mulching is widely used in croplands to improve yields, while its mismanagement leads to plastic pollution in rural areas. China has explored different approaches to manage post-use plastic mulching, while there is still inadequate research regarding their corresponding environmental impacts. This study establishes five plastic mulching management scenarios, i.e., plastic mulching disposed of in nature, substituting biodegradable plastic, recycling, incineration, and landfilling, and maize cultivation in rural areas of northern China was taken as the studied case. We determine the comprehensive environmental impacts through a life cycle assessment (LCA) approach and completed a field investigation to obtain local datasets. The impurity content of used polyethylene mulching (PEM), an essential parameter for the entire life-cycle environmental impact assessment, is 80.1% ± 9.5%, examined by on-site sampling and scanning electron microscope. Results show that: 1) the use of biodegradable mulching (BM) instead of traditional PEM reduces carbon emissions by 22.6%; 2) the increment of soil carbon flux caused in the application stage is more significant than that in the post-use stage; 3) incineration of post-use mulch causes relatively significant photochemical oxidant formation effect; furthermore, recycling of plastic mulching leads to negative impacts in terms of human toxicity effect, meanwhile the positive environmental impact of fossil depletion effect is 2.3 times higher than that of incineration. Reducing the rate of impurity content in wasted plastic mulching can reduce transportation costs and promote sustainable plastic pollution management in rural areas. • Life-cycle environmental impacts analysis of plastic mulching. • Compare five scenarios on managing wasted plastic mulching. • Collected waste mulch films contain 80% of soil-like impurities. • Incineration with energy recovery offset generates lowest GHG emission. • Recycling generates the lowest fossil depletion and photochemical effects. [ABSTRACT FROM AUTHOR]

This study investigated the effects of fingertip tactile sensitivity on the structural variability of thumb and index finger forces during stable precision grip. Thirty right-handed healthy subjects participated in the experiment. Transient perturbation of tactile afferents was achieved by wrapping up the distal pads of the thumb or index finger with transparent polyethylene films. The time-dependent structure of each digit force and the variability of interdigit force correlation were examined by detrended fluctuation analysis (DFA) and detrended cross-correlation analysis (DCCA), respectively. Results showed that the tactile sensitivity affected αDFA of the vertical shear force Fx (F3,239 = 6.814, p<0.001) and αDCCA of Fx (χ2 = 16.440, p<0.001). No significant difference was observed in αDFA or αDCCA of the normal forces produced by the thumb or index finger. These results suggested that with blurred tactile sensory inputs the central nervous system might decrease the vertical shear force flexibility and increase the interdigit shear force coupling in order to guarantee a stable grip control of an object against gravity. This study shed light on the feedback and feed-forward strategies involved in digit force control and the role of SA-II afferent fibers in regulation of vertical shear force variability for precision grip. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate whether a periosteum patch could enhance polyethylene terephthalate (PET) artificial ligament graft osseointegration in a bone tunnel. 12 female goats underwent ACL reconstruction with a PET artificial ligament graft in the right knees. Right knees in 6 goats were reconstructed with periosteum patch-enveloped PET grafts (Periosteum group) in the tibia bone tunnel, whereas the other 6 goats had no periosteum patch and served as the Control group. All the goats were sacrificed at 12 months after surgery. 3 tibial-graft complex samples in each group were harvested consecutively for microcomputed tomography (micro-CT) scan, magnetic resonance imaging (MRI) scan and histological evaluation. The other 3 tibial-graft complex samples in each group were harvested for biomechanical testing. The mean pull-out load of the Periosteum group (208±25N) at 12 months was significantly higher than that of the Control group (1O7±13JV) (p = 0.0044). According to the micro-CT scan, more new bone formation was observed at the graft-bone interface in the Periosteum group compared with the Control group. Furthermore, MRI showed that the Periosteum group appeared to have a better graft osseointegration within the bone tunnel compared with the Control group. Histologically, application of a periosteum patch induced more new bone and Sharpey's fiber formation between the graft and bone tunnel compared with the controls. The study has shown that periosteum enveloping of the PET artificial ligament has a positive effect in the induction of artificial ligament osseointegration within the bone tunnel. [ABSTRACT FROM AUTHOR]

To measure the extended-range neutron spectra and calibrate the extended-range neutron dosemeters of the China initiative Accelerator-Driven System (CiADS), an Extended-range Bonner Sphere Spectrometer (EBSS) has been developed. The EBSS was designed based on the PHITS codes, investigating various combinations of materials and diameters of the neutron moderators and the neutron multipliers for extended-range neutrons. Finally, seven polyethylene-only spheres and seven extended-range spheres were selected and subsequently built. The neutron multipliers of the extended-range spheres embedded concentric shells of lead, copper and tungsten. The response functions of the EBSS were analyzed and experimentally validated. It was subsequently tested with 252Cf neutron source and cosmic ray neutron source. The results demonstrate that the EBSS is capable of accurately measuring neutron spectra., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Microplastics, which are usually recognized as artificial polymer particles with a particle size <5 mm, have attracted much attention as new pollutants in recent years. Urban areas are a major contributor of microplastics to the environment, but their microplastic emission intensity and characteristics are not clear. In this paper, the microplastic abundances and characteristics in the Southern Jiangsu Canal were studied to reveal the effect of riverside cities on microplastics in river water. The results show that the microplastic abundance in the water body of the South Jiangsu Canal ranges from 3.41 to 19.07 particles L -1 , with an average of 9.59 ± 3.95 particles L -1 , which is at the same level as major urban agglomerations in the world. The top five polymers were polyethylene terephthalate (PET), polycarbonate (PC), polyethylene (PE), chlorinated polyethylene (CPE) and polyurethane (PU). Fragments accounted for the largest proportion (68.47 %), followed by beads and fibers. Most microplastics were <100 μm (83.87 %). Human life and industry in riverside cities contribute significantly to microplastics in the Southern Jiangsu Canal water. After flowing through the cities, the microplastic abundance in the canal water increased by 26 % ~ 211 %. The overall economic and social development of the city affects the occurrence characteristics of the canal water microplastics. The average abundance of microplastics was positively correlated with Regional Gross Domestic Product (GDP) per capita. Wastewater treatment plant effluent is an important point source of microplastics in canal water. The microplastic abundances downstream of WWTPs increased by 21.8 % ~ 64.6 % compared with those upstream., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

This study aimed to explore the occurrence state, morphological characteristics, polymer types, as well as potential ecology of microplastics in the Weihe River in Northwest China. Thus, we identified the abundance distribution, shape, particle size, color, and polymer type of microplastics in the surface water of the Weihe River by conducting field sampling, microscope observation, Fourier infrared spectroscopy, Micro-Raman spectroscopy, etc., during the normal water period (May) of 2021. Subsequently, we analyzed the potential ecological and environmental risks of microplastics using the pollution load index method and species sensitivity distribution method. The results showed that microplastics were detected to exist in all sampling points and the abundance ranged from (2.9±0.8) to (10.3±2.8) n·L -1 . The concentration of microplastics in the main stream of the Weihe River was higher than that in the tributaries. Fiber (15.04%-77.03%), small size (<0.5 mm) (27.27%-89.38%), and colored (15.85%-49.53%) were the predominant microplastic types. Polyethylene (32.98%), polypropylene (29.79%), polystyrene (21.21%), and polyethylene (10.61%) terephthalate were the main types of polymers detected. In general, the microplastic pollution in Weihe River was at a medium level and had not affected aquatic organisms, but its high concentration and the characteristic of the plastics to adsorb other pollutants are still of concern.

Background: Giant cell tumors (GCT) of the distal radius at Campanacci grade II/III are particularly challenging to treat. Wide excision is the management of choice, but this creates a defect at the distal end of radius. We treated 11 cases of GCT of the distal radius by en bloc excision and custom prosthetic replacement. The purpose of this study was to present our experience and assess the functional outcomes of all patients treated with this surgery.Materials and Methods: Between 2005 and 2014, we followed up 11 patients with GCT of the distal radius who were treated with en bloc excision and custom prosthetic replacement. All cases were evaluated based on clinical and radiological examinations, passive range of motion (ROM) of the wrist joint, complications, and Musculoskeletal Tumor Society (MSTS) score.Results: Mean follow-up period was 55.5 months (24-83 months); mean resected length of the radius was 7.9 cm. One patient had tumor recurrence in the soft tissues after 15 months (recurrence rate 9.09 %). No patient had fracture, recurrence in the bone, metastases, or immune rejection. No complications were seen, such as loosening, rupture, or dislocation of the custom prosthesis. One patient developed superficial infection at the operative site which resolved after a course of antibiotics for 4 weeks. One patient experienced pain, which could be endured without the need for analgesics. Average ROM was 40.9° of dorsiflexion, 30.0° of volar flexion, 46.4° of supination, and 38.2° of pronation. Mean grip strength was 71 % (42-86 %). Overall revised MSTS score averaged 80.3 % (63.3-93.3 %) with one being excellent, five good, and five satisfactory.Conclusion: En bloc excision and custom prosthetic replacement for a Campanacci grade II/III GCT of the distal radius results in reasonable functional outcome at intermediate follow-up evaluation. Although average ROM of the ipsilateral wrist is poorer than some studies with other techniques, this method can be considered a reasonable option. [ABSTRACT FROM AUTHOR]

Estuarine Microplastics (MPs) are limited to know globally. By filtering subsurface water through 330 μm nets, MPs in Jiaojiang, Oujiang Estuaries were quantified, as well as that in Minjiang Estuary responding to Typhoon Soulik. Polymer matrix was analyzed by Raman spectroscopy. MP (<5 mm) comprised more than 90% of total number plastics. The highest MPs density was found in Minjiang, following Jiaojiang and Oujiang. Fibers and granules were the primary shapes, with no pellets found. Colored MPs were the majority. The concentrations of suspended microplastics determine their bioavailability to low trophic organisms, and then possibly promoting the transfer of microplastic to higher trophic levels. Polypropylene and polyethylene were the prevalent types of MPs analyzed. Economic structures in urban estuaries influenced on MPs contamination levels. Typhoon didn't influence the suspended MP densities significantly. Our results provide basic information for better understanding suspended microplastics within urban estuaries and for managerial actions. [ABSTRACT FROM AUTHOR]

Since a high-density polyethylene membrane has good mechanical properties and stable chemical properties, it is widely used in all kinds of anti-permeable layers. But for a sewage pool of a drilling engineering in the western desert oil field, it is not only facing a high temperature and drying environment, but also quite a complex drilling fluid composition. Yet an experimental study system on application has not set up in China. According to the working environment of the high-density polyethylene membrane, a series of aging tests are carried out in the paper. Measured the change value of the high-density polyethylene membrane, mechanical properties are expressed directly the aging properties of high-density polyethylene membranes. [ABSTRACT FROM AUTHOR]

Plastic pollution in farmland ecosystems has been widely concerned. However, the heterogeneity and driving mechanisms of plastic residue (PR) remain unclear in the farmland surrounded by complex pollution points. In this study, the abundance, mass, and accumulation areas of PR of mulch film (MF) and non-MF (NMF) were investigated in a large area of the vegetable field covered by plastic mulching in a long-term in Northeast China. Geostatistics combined with classical statistics were used to clarify how pollution source and migration factors change the PR heterogeneity in the farmlands. Results indicated that the MF type was only polyethylene (PE) (79.1 % of total PR), while NMF accounted for 20.9 % of total PR. As well, NMF-polypropylene (PP) and NMF-PE accounted for 45.3 % and 39.7 % of total NMF respectively, followed by polystyrene accounting for 7.5 %. In the 0-20 cm soil layer, the spatial autocorrelation of mass and accumulation areas of MF were significantly (p < 0.05) positive, and their spatial pattern tended to cluster. The accumulation areas of MF was predoniment in northwest and southeast near the roadside in all soil layers, while the accumulation areas of NMF was higher near the landfill in the 0-20 cm soil layer. Landfill and residential areas were critical sources of PR for the farmland. Southwest wind and southeast wind were the main driving force of PR migration and their annual migration rates were 23.7 and 19.8 m·year -1 . The functional groups on the surface of plastics were different after degradation (including different types and different utilization methods), and PR was oxidized could release or adsorb toxic substances from the soils. Generally, in order to reduce PR pollution, in addition to source control and recycling, farmland tillage should be avoided in the weather when the wind speed is strong, especially near the PR pollution source., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

To investigate the effects of plastic film mulches and their residual films after use on soil bacterial communities, mulching experiment and the subsequent residual film experiment were conducted on winter-planting potato field in two locations. During mulching experiment, treatments biodegradable film mulch (BM) and PE film mulch (PM) reduced soil nutrient regarding available nitrogen and available potassium, as well as microbial biomass carbon (MBC), but increased urease activity, as compared to treatment no film mulch (NM). Soil moisture was significantly elevated by mulching practices and correlated with more microbial phyla than the other tested soil properties, indicating its important role in shaping soil bacterial communities. In addition, mulching practices increased alpha diversity of soil bacteria, although location heterogeneity was observed. Network analyses showed that both treatments BM and PM promoted the interrelations within bacterial communities and harbored more keystone taxa than treatment NM. During residual film experiment, residual films from BM and PM were incorporated into soil after harvest of potato. Treatment residual biodegradable film (RBF) significantly increased the content of MBC and activity of β-glucosidase (BG) as compared to treatments residual PE film (RPF) and no residual film (NRF), and BG had the most correlations with microbial phyla among all the tested soil properties. Treatments RBF and RPF increased the relative abundance of some dominant bacterial phyla, including Bacteroidetes, Actinobacteria, and Chlorofexi, and enhanced the interrelations within bacterial community, whereas more keystone taxa were harbored by treatment RBF, due to the increase of keystone taxa in phyla Acidobacteria, Actinobacteria, Bacteroidetes, and Proteobacteria. These results indicate that the indirect effects of biodegradable and PE film mulch as a soil surface barrier on soil are similar, whereas their direct effects via incorporation into soil as residual films show specificity., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The increasing microplastics (MPs) pollution and continuous acid rain coincide in many areas of the world. However, how MPs interact with acid rain is still unclear. Herein, we conducted a microcosm experiment to decipher the combined effect of polyethylene (PE) MPs (1%, 5%, and 10%) and acid rain (pH 4.0) on the agricultural soil ecosystem of Southern China, in which edaphic property, microbial community, enzymatic activity and CO 2 emission were investigated. The results showed that PE MPs significantly decreased soil water retention and nitrate nitrogen content regardless of acid rain. Soil total nitrogen significantly decreased under the co-exposure of 10% PE MPs and acid rain. However, PE MPs did not alter soil microbial biomass, i.e., the content of microbial biomass carbon, total phospholipid fatty acids, with or without acid rain. 10% PE MPs and acid rain treatment significantly increased the activity of catalase and soil CO 2 emission. PE MPs addition did not affect the temperature sensitivity (Q 10) of soil CO 2 emission regardless of acid rain. These findings suggest that MPs may interact with acid rain to affect soil ecosystems, thus underscoring the necessity to consider the interaction between MPs and ambient environmental factors when exploring the impact of MPs on the soil biodiversity and function. [Display omitted] • Co-exposures of polyethylene (PE) microplastics (MPs) and acid rain promoted soil CO 2 emission. • PE MPs decreased soil water retention regardless of acid rain. • Co-exposures of PE MPs and acid rain reduced soil nitrogen availability. • Soil microbial biomass was not affected by the PE MPs with or without acid rain. • Co-exposures of PE MPs and acid rain increased the activity of catalase. [ABSTRACT FROM AUTHOR]

The role of microplastics in burying hydrophobic organic compounds remains largely unknown. Sediment cores collected from the center of a typical urban lake (Lake Qianhu) in China were chosen to explore the contribution of microplastics to the burial of polycyclic aromatic hydrocarbons (PAHs) by sediments, and to elucidate how this contribution changed with microplastic composition and the hydrophobicity of PAHs on a decade scale. Our results showed that the concentration of individual PAHs adsorbed by microplastics varied from detection limit (LOD) to 7.2 mg g -1 MP, which was much higher than the LOD to 31.0 μg g -1 TOC buried by total organic carbon. However, the amount of individual PAHs adsorbed by microplastics only contributed to 0-34.2% of that in sediments. Changes in the composition of microplastics, including the increased proportion of polyethylene and polypropylene : polyethylene polymer in sediments, resulted in the average microplastic sediment burial ratios (MSBRs) of most PAHs increasing by 0.13% to 2.7% in the period from 1997 to 2018 compared with those in the period from 1975 to 1996. The average MSBRs varied with the hydrophobicity of PAHs, which increased with log  K ow value if it varied from 3.45 to 5.20, but decreased with log  K ow if it was in the range of 5.30 to 6.50. Our study provides novel knowledge on the contribution of microplastics to the burial of PAHs by sediments.

Studies have shown that mulching agricultural fields with plastic residues can influence microbial communities in the environment, but few studies have investigated the differences in the soil microbial communities in distinct areas under mulching with different colored plastic products. Thus, in this study, we explored how different colored polyethylene mulching films (PMFs) might affect soil bacterial communities during enrichment incubation. We found significant differences in the bacterial communities under different colored PMFs after incubation. Treatment with the same colored PMF obtained more similar bacterial community compositions. For instance, at the class level, Gammaproteobacteria and Bacteroidia were most abundant with black PMF, whereas Actinobacteria and Bacteroidia were most abundant with white PMF. The most abundant genera were Acinetobacter and Chryseobacterium with black PMF but Rhodanobacter and Paenarthrobacter with white PMF. Polyethylene- and hydrocarbon-degrading bacteria were the core members detected under both treatments, and the bacterial communities were predicted to have the potential for the biodegradation and metabolism of xenobiotics after enrichment culture according to the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) tool. In addition, the bacterial communities in soil from Xinjiang treated with white PMF and in soil from Yangling treated with black PMF were strongly correlated and stable. Our results suggest that the color of the PMF applied affected the soil bacterial communities, where plastics with the same color may have recruited similar species of microorganisms, although the origins of these microorganisms were not the same., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

The aquaculture environment, especially the culture ponds and aquaculture products, is considered to be an important reservoir of colistin resistance genes. However, systematic investigations of colistin resistance in Penaeus vannamei farming in different culture modes are scarce. In this study, a total of 93 non-duplicated samples were collected from P. vannamei farms in five cities in China from 2019 to 2021. The prevalence, antibiotic resistance and multilocus sequence typing (MLST) of colistin-resistant bacteria were measured and analysed. The results showed that among the 1601 isolates in P. vannamei and its environmental samples, the pollution of colistin-resistant bacteria was serious (the overall prevalence was 37.3% and 28.8%, respectively), regardless of the earthen pond or high-density polyethylene (HDPE) film-lined pond. Among 533 isolates, the prevalence of mobile colistin resistance (mcr) genes, mcr-1, was the highest (60%, 320/533), followed by mcr-4 (1.5%, 8/533), mcr-8 (0.9%, 5/533), mcr-10 (0.6%, 3/533) and mcr-7 (0.4%, 2/533). The prevalence of mcr-1 in earthen ponds was significantly higher than that in HDPE film-lined ponds (67.5% vs. 49.1%, p < .001). The dominant strain carrying mcr-1 was Bacillus spp. (54.1%, 173/320), followed by Enterobacter spp. (8.1%, 26/320), Staphylococcus spp. (6.3%, 20/320) and Aeromonas spp. (5.3%, 17/320). The antibiotic resistance profiles of 173 Bacillus spp. varied among different sampling locations and culture types. These isolates were highly resistant to cefepime, ceftriaxone, trimethoprim-sulfamethoxazole and ceftiofur (>45%), and multidrug-resistant isolates were common (62.4%, 108/173). Sequence type (ST) 26 (37/66, 56%) was found to be the most prevalent ST in mcr-1-positive Bacillus cereus isolated from the aquaculture environment. In summary, our study pointed out that it is necessary to continuously monitor antibiotic usage and its residues regardless of the pond types, especially with regard to critical drugs such as colistin., (© 2022 John Wiley & Sons Ltd.)

Microplastics (MPs) implications in the atmosphere are of current global concern. Currently, there is a growing interest regarding source appointment, fate, level of toxicity, and exposure intensity of ambient air MPs. Recent data suggest that polyethylene (PE) dominates ambient MPs in China's megacities. Albeit understanding of PE sources is limited and restricted to typical sources polluting terrestrial and marine environments. However, the air is a distinct environmental component and may have some separate pollution sources as well as the relative contribution of different sources could also contrast in different environments. Urbanization and fast construction activity resulting from increased economic growth in these places might be a potential source of ambient PE. Recently, the use of scaffold netting on construction sites and synthetic grass as land covering sheets has been on the rise. Generally, these PE items are often inferior and composed of recycled material, making them more prone to degradation. Also, because these items were continually exposed to open air, there is a considerable risk of fragmentation and atmospheric mixing. Therefore, unchecked and excessive usage of these materials can be risky. Here, PE's physical and chemical characteristics, transport and health risks in urban air are discussed here. [Display omitted] • Fragments of PE-MPs showed long persistance in atmosphere. • Synthetic grass and scaffold nets could be major sources of PE-based MPs in the air. • Inferior quality and continuous exposure to open-air enhance PE fragmentation. [ABSTRACT FROM AUTHOR]

Xuanwei and Fuyuan, two counties located in southwest China, are areas with known high lung cancer incidence. Pollution relative to coal combustion, especially serious air pollution generated by burning smoky coals in unvented households, has been thought to be the most predominant cause. Possible inorganic carcinogenic matter including radon in air and arsenic, lead, chromium, cadmium, nickel, and beryllium in water, soil, and coal were sampled and examined to find the current pollution status, distributions, characteristics, and relationships to the lung cancer incidence. The concentrations of mercury in air of Xuanwei and Fuyuan ranged from 1.7 to 205.3 ng/m3 (indoor), 1.3 to 7.5 ng/m3 (ambient). No radon concentration exceeded the World Health Organization standard. Results indicated that household stove improvement by changing stoves from unvented to vented obviously alleviated the indoor air pollution of carcinogenic metals. Most of the carcinogenic metals were also found at very low levels in water and soil, which therefore had little influence on human health. Concentrations of these elements at different sites did not vary in any relation to lung cancer incidence. The study described in this article added basic data; the results of the authors' study will be helpful in determining pollution status and to future studies on the etiology of lung cancer. [ABSTRACT FROM AUTHOR]

In 2011, polyester fibres retained high growth rates: staple fibre 7% and complex yarn 6%; their output was 14.4 and 24 million tons, respectively. The major growth occurred in China 83% for yarn (208∙10 tons) and 82% for staple fibre (789∙10 tons). By the end of 2013, the global growth of PE complex yarn is expected to rise over 2011 by 35.6% and of staple fibre by 16.1%. The dynamics of global demand shows dominance of China whose share in the global textile balance by 2020 will be 66% for yarns and about 47% for staple fibre. Over the same period their demand will fall in Western Europe and rise a little in CIS countries and Russia. Belarus companies, as before, remain flag bearers in polyester production in CIS countries, but their growth is proceeding differently: Mogilevkhimvolokno is gradually reducing fibre output and taking a fancy toward products they are not specialized for (food PET, preforms, etc.) and Svetlogorskkhimvolokno, on the contrary, steeply raised PE textile yarn production capacity (to 38.5∙10 tons/yr). In Russia, PE fibres, mainly staple, continue to be made from wastes of regenerated PET, a substantial quantity of which is procured for import, and endless negotiations are being conducted on large-scale indigenous production. [ABSTRACT FROM AUTHOR]

Purpose: Suspended particulate sediment (SPS) concentration has a great impact on the sediment to water partitioning coefficients ( K) of hydrophobic organic compounds (HOCs), which is called the particle concentration effect (PCE). However, the mechanisms regarding the PCE are not yet well understood, and there is little direct experimental evidence for these mechanisms. The aim of this study was to investigate the PCE of polycyclic aromatic hydrocarbon (PAH) sorption on sediment by analyzing the freely dissolved concentrations of PAHs. Materials and methods: Sediments were collected from the Yellow River and the Haihe River in China. Pyrene was selected as a model PAH to investigate the sorption of PAH on sediments. In addition to the total dissolved concentration ( C) of pyrene, the freely dissolved concentration ( C) measured by polyethylene devices was used to investigate the PCE of pyrene in the presence and absence of phenanthrene and chrysene. Results and discussion: For both the Haihe River and Yellow River sediments, in the presence and absence of other PAHs, the K value of pyrene with C as the equilibrium concentration in the water phase was approximately two times higher than that with C as the equilibrium concentration. With either C or C as the equilibrium concentration in the water phase, the K value of pyrene decreased with increasing SPS concentration as a power function. In addition, the K value with C as the equilibrium concentration decreased faster than that with C. This inferred that, apart from a third phase including dissolved organic carbon (DOC) and colloids, particle-particle, or particle-DOC interactions were important for the PCE. The contribution of the third phase to the PCE for the Haihe River sediment (72.5 ± 26.4 %) was greater than the contribution for the Yellow River sediment (48.4 ± 16.2 %), which had a larger particle size and lower total organic carbon and black carbon contents. Conclusions: The PCE of PAH sorption onto sediments was attributed to both the third phase and to particle-particle or particle-DOC interactions. The contribution of the third phase to the PCE depended on both the TOC content and the particle size of sediment. As high SPS and DOC concentrations exist in many rivers, their effects on the sorption of HOCs should be considered when conducting bioavailability and ecological risk assessment. [ABSTRACT FROM AUTHOR]

The different types of microplastics (MPs), including debris, fibers, particles, foams, films and others, have become a global environmental problem. However, there is still a lack of research and understanding of the pollution characteristics and main causes of MPs in the arid region of Xinjiang, China. In this survey, we focused on the occurrence and distribution of MPs in urban, farmland and desert areas along a highway in the survey area. Our results showed that the main types of MPs were polypropylene (PP) flakes, polyethylene (PE) films and both PE and PP fragments and fibers. The abundance levels of MPs in street dust of Korla, Alar and Hotan districts equaled 804, 307 and 1526 particles kg−1, respectively, and were positively correlated with the urban population. In farmland areas, there were only two types of MPs (films and fibers), of which the film particles dominated and accounted for 91% of the total on the average. The highest abundance rate of MPs reached 7292 particles kg−1 in the desert area along the highway. The minimum microplastic particle sizes were 51.8 ± 2.2 μm in urban street dust samples, 54.2 ± 5.3 μm in farmland soil samples and 67.8 ± 8.4 μm in samples from along the desert highway. Particle sizes < 500 μm were most common and accounted for 48−91% of the total in our survey. The abundance and shape distribution of the MPs were closely related to the different types of human activities.

Plastic film mulching can increase crop yield and is widely used in agricultural production, but long-term mulching could adversely affect plant growth. To investigate the related mechanism, we studied the bacterial communities in different root-associated compartments of Paeonia ostii, a perennial oil crop, under polyethylene film mulching for three years by full-length 16S rDNA sequencing technology, and measured the soil physicochemical properties and enzyme activities. We found that enzyme activities and available nutrients in the soil tended to decrease after long-term mulching. Analysis of bacterial community composition revealed that the endosphere may be another potential source of the root-associated microbiome of P. ostii, and the rhizoplane plays a selective gating role in the enrichment processes for P. ostii microbiome assembly. Long-term mulching affected the abundance of dominant bacterial communities in different root-associated compartments and reduced the bacterial richness in the endosphere, but increased bacterial interactions in each compartment, as well as between different compartments. We speculate that this is mainly related to the decrease of litter content and the serious degradation of polyethylene film after long-term mulching, which resulted in microplastics and other harmful substances entering the soil. Our study further explained the reasons for the harm of long-term film mulching on plants to guide the rational use of plastic film. KEY POINTS: •Soil enzyme activities and available nutrients decreased after long-term mulching. •Mulching affected the dominant bacterial abundance in different root-associated compartments. •Mulching increased bacterial interactions among compartments., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)