Researchers have tried hard to study the toxic effects of single pollutants like certain antibiotics and nanoplastic particles on plants. But we still know little about how these pollutants interact when they're together in the environment, and what combined toxic effects they have on plants. This study assessed the toxic effects of polystyrene nanoplastics (PS-NPs) and ciprofloxacin (CIP), both individually and in combination, on soybean (Glycine max L.) seedlings by various concentration gradients treatments of PS-NPs (0, 10, 100 mg/L) and CIP (0, 10 mg/L). The results indicated that high concentrations of PS-NPs significantly impeded soybean seedling growth, as evidenced by reductions in root length, plant height, and leaf area. CIP predominantly affected the physiological functions of leaves, resulting in a decrease in chlorophyll content. The combined exposure demonstrated synergistic effects, further intensifying the adverse impacts on the growth and physiological functions of soybean seedlings. Metabolomic analyses indicated that single and combined exposures markedly altered the metabolite expression profiles in soybean leaves, particularly related to amino acid and antioxidant defense metabolic pathways. These results indicate the comprehensive effects of NPs with antibiotics on plants and provide novel insights into toxic mechanisms.

Nanoplastics (NPs) and zinc (Zn), both widespread in soil environments, present considerable risks to soil biota. While NPs persist environmentally and act as vectors for heavy metals like Zn, their combined toxicity, especially in soil invertebrates, remains poorly understood. This study evaluates the individual and combined effects of Zn and NPs on earthworm coelomocytes and explores their interactions with Cu/Zn-superoxide dismutase (SOD), an antioxidant enzyme. Molecular docking revealed that NPs bind near the active site of SOD through pi-cation interactions with lysine residues, further stabilized by neighboring hydrophobic amino acids. Viability assays indicated that NPs alone (20 mg/L) had negligible impact (94.54 %, p > 0.05), Zn alone (300 mg/L) reduced viability to 80.02 %, while co-exposure reduced it further to 73.16 %. Elevated levels of reactive oxygen species (ROS) and malondialdehyde (MDA) levels were elevated to 186 % and 173 % under co-exposure, alongside greater antioxidant enzyme disruption, point to synergistic toxicity. Dynamic light scattering and zeta potential (From -13 to -7 mV) analyses revealed larger particle sizes in the combined system, indicative of enhanced protein interactions. Conformational changes in SOD, such as alpha-helix loss and altered fluorescence, further support structural disruption. These findings demonstrate that co-exposure to NPs and Zn intensifies cellular and protein-level toxicity via integrated physical and biochemical mechanisms, providing critical insight into the ecological risks posed by such co-contaminants in soil environments.

Typically, nanoplastics (NPs) are contaminated before entering soil, and the impact of NPs on the biotoxicity of Persistent Organic Pollutants (POPs) they carry remains unclear. This study simulated two environmentally relevant scenarios: singular exposure of benzo[a]pyrene (BaP) in soil and exposure via NPs loading (NP-BaP). Correlation analysis and machine learning revealed that injury in earthworms exposed for 28 days was significantly associated with NPs. Moreover, when the soil exposure concentration of BaP was 4 mg/kg, the NP-BaP group exhibited 10.67 % greater pigmentation than the BaP-only group. Despite the lower biota soil accumulation factor (BSAF) of earthworms in the NP-BaP group, the concentration of BaP in the soil remained at higher levels in the late stages of exposure. This led to NP-BaP inducing a stronger trend of oxidative damage compared to BaP alone. Furthermore, molecular-level studies indicated that the differential preferences of NPs and BaP for damaging antioxidant enzymes were linked to individual oxidative stress responses. This study confirmed that NPs, at non-toxic concentrations, could increase the persistence of BaP's biological toxicity after prolonged exposure, highlighting the potential safety risks of NPs as carriers of POPs to soil organisms.

Soil is an important sink for microplastics (MPs) and pesticides. MPs can act as carriers for pesticides, thus induce direct and indirect effects on soil organisms. Fluindapyr (FIP), a novel succinate dehydrogenase inhibitors fungicides (SDHIs), may pose a serious threat to earthworms. However, few studies have evaluated the effects of joint exposure to MPs and FIP. Here, earthworms (Eisenia fetida) were jointly exposed to PMMA (polymethylmethacrylate) and PS (polystyrene) MPs of different sizes (0.1, 1 and 10 mu m) along with FIP for 28-day to investigate the toxic effects of single and joint exposure of FIP and MPs on earthworms. The results showed that joint exposure to 0.1 and 1 mu m MP promoted the accumulation of FIP in earthworms at the beginning of the experiment compared to the sole group, but the elimination of FIP from earthworms accelerated after 14 d. In addition, the joint exposure caused more serious damages to the epidermis and intestine of earthworms and increased the severity of oxidative stress. The effects of joint exposure to FIP and MPs depended on the size of the MPs, and the strongest effects were observed in the treatment with the smallest size. The 16S rRNA sequencing results showed that the joint exposure to MPs and FIP didn't cause gut microbiota dysbiosis. However, the sole 0.1 mu m PS significantly altered the community diversity and richness of earthworm gut bacteria, and the relative abundance of Proteobacteria, Actinobacteria and Firmicutes was significantly changed. The obtained results inferred that MPs could influence environmental and toxicological behaviors of FIP and may provide data support for the risk assessments of MPs and FIP on soil ecosystems.

The high global production combined with low recycling rates of polystyrene (PS) and low-density polyethylene (LDPE) contributes to the abundance of these commonly used plastics in soil, including as microplastics (MPs). However, the combined effects of MPs and heavy metals, such as arsenic (As) on earthworms are poorly understood. Here, we show that neither PS nor LDPE altered the effects of As on the survival, growth, and reproduction of the earthworm Eisenia fetida. As stress, both alone and in combination with the MPs, induced DNA damage in coelomocytes. In As-exposed earthworms, PS and LDPE increased the accumulation of reactive oxygen species while the activities of the antioxidant enzymes peroxidase, superoxide dismutase, and catalase were significantly lower under combined PS/LDPE + As exposure than under As exposure alone. As stress alone reduced cocoon production and the mRNA level of the reproduction-related gene ANN whereas As combined with PS/LDPE reduced the mRNA levels of CYP450, an enzyme involved in detoxification. Integrated biomarker response analysis revealed that PS/LDPE did not significantly impact the overall ecotoxicological effects of As exposure on earthworms. This study provides important insights into the potential ecological risks of MPs in heavy-metal-contaminated soil.

A dynamic triaxial test was conducted to assess the deformation characteristics of sodium silicate modified EPS (expanded polystyrene) particle lightweight soil (SCS) under cyclical loading. The hysteresis curves, dynamic elastic modulus, damping ratio, and cumulative strain were obtained for SCS samples with varying EPS particle content. We found that the samples' stress-strain hysteresis curves, became crescent-shaped for different dynamic stress situations, and were largely elastic in the latter phases. Furthermore, there was a progression from dense to sparse as EPS content increased. With increasing dynamic stress, the dynamic elastic modulus and damping ratio of SCS also rose. The damping ratio of SCS rose as the EPS particle content increased, whereas the dynamic elastic modulus decreased. Notably, increases in the PS particle content and dynamic stress largen the deformation of the SCS samples. Moreover, we found that when the cumulative strain curve becomes stable, varying the contents of EPS particles under different dynamic stresses leads to a power function relationship with the logarithm of the number of cyclic loading cycles. In cases where the cumulative strain curve reaches a critical or destruction point, the cumulative damage variable displays a power function relationship with the vibration count.

Polystyrene nanoplastics (PS-NPs) have been demonstrated to accumulate in organisms especially from soil and exhibit neurotoxicity. However, the specific mechanisms by which PS-NPs caused neurotoxic effects remain largely unexplored. In this study, we employed PS-NPs with a diameter of 50 nm as the toxicant and used estimated exposure concentrations which are similar to those found in Chinese agricultural soil (i.e., 0, 1, 5 and 10 mu g/mL). We found that PS-NPs induced significant neurotoxicity and behavioral damage in nematodes. Taking advantage of neuronal-specific reporter nematodes, we unveiled the order of neuronal damage induced by PSNPs being DAergic neurons, followed by Achergic neurons and GABAergic neurons. Additionally, PS-NPs significantly reduced the neurotransmitter levels corresponding to these three types of neurons, with the order of reduction being Ach followed by DA and GABA. Moreover, we demonstrated that PS-NPs led to an increase in ROS production, the activation of gst-4 and a decrease in Sod-2 protein content. Furthermore, we unveiled that Sod-2 could suppress the generation of ROS induced by PS-NPs. Then we proved that the pretreatment with mitochondrial ROS scavenger Mitoquinone (Mito Q) was able to alleviate PS-NPs-induced neurotoxic effects and behavioral damage by scavenging ROS and subsequently regulating Sod-2 protein expression. In summary, we have demonstrated for the first time that ROS-mediated reduction of Sod-2 protein plays a crucial role in PS-NPsinduced neurotoxicity and behavioral damage. Furthermore, Mito Q shows potential therapeutic value in alleviating the toxic effects of PS-NPs, providing new insights for the prevention and treatment of PS-NPs-induced neurotoxicity.

This study explores the feasibility and benefits of utilizing plastic waste in the production of construction materials, specifically composite bricks. The escalating accumulation of plastic waste poses significant environmental challenges, which necessitates innovative approaches for recycling and re-utilization to mitigate pollution and reduce landfill use. Our research focuses on the synthesis of bricks by incorporating high-density polyethylene (HDPE) and polystyrene (PS) with sand brick powder, utilizing a compatibilizer (SBS-g-MA) to enhance interfacial adhesion and mechanical integrity. The experimental methodology involved the preparation of composite materials through melt mixing, followed by molding to form brick specimens. These were analyzed for their mechanical properties, including tensile strength, Young's modulus, and elongation at break, as well as thermal properties such as degradation temperature and crystallization behavior. Results showed that the inclusion of sand brick powder significantly enhances the thermal stability of the composites, as evidenced by the higher degradation temperatures observed. Specifically, the degradation temperature increased from 300.59 degrees C in pure HDPE/PS blends to 420.39 degrees C in composites with 7% brick powder, suggesting the formation of a protective barrier against thermal decomposition. Moreover, mechanical testing revealed that composites with up to 7% brick powder exhibited improved tensile strength and Young's modulus compared to pure polymer blends.

In this paper we present experimental investigation of the frequency dependence of nonlinear elastic (Murnaghan) moduli of polystyrene samples by the ultrasonic method based on the acousto-elastic effect. Measurements were performed in a wide frequency range, from 250 kHz to 2.5 MHz. The absolute values of the Murnaghan moduli demonstrated considerably nonlinear dependencies on the ultrasound frequency. While at higher frequencies above similar to 600 kHz no significant variations of the moduli occurred, at lower frequencies a drastic rise of absolute values in several orders of magnitude has been observed. The values obtained at lower frequencies were utilized for theoretical estimation of parameters of a strain solitary wave in this material. The data obtained correlated well with the parameters obtained experimentally and allowed for explaining the long-lasting discrepancy between theoretical estimations and experimental results.

Nano polystyrene (PS) particles and antibiotics universally co-exist, posing a threat to crop plants and hence human health, nevertheless, there is limited research on their combined toxic effects along with major influential factors, especially root exudates, on crop plants. This study aimed to investigate the response of Chrysanthemum coronarium L. to the co-pollution of nanoplastics and tetracycline (TC), as well as the effect of root exudates on this response. Based on a hydroponic experiment, the biochemical and physiological indices of Chrysanthemum coronarium L. were measured after 7 days of exposure. Results revealed that the co-pollution of TC and PS caused significant oxidative damage to the plants, resulting in reduced biomass. Amongst the two contaminants, TC played a more prominent role. PS could enter the root tissue, and the uptake of TC and PS by plant roots was synergetic. Malic acid, oxalic acid, and formic acid could explain 65.1% of the variation in biochemical parameters and biomass of the roots. These compounds affected the photosynthesis and biomass of Chrysanthemum coronarium L. by gradually lowering root reactive oxygen species (ROS) and leaf ROS. In contrast, the impact of rhizobacteria on the toxic response of the plants was relatively minor. These findings suggested that root exudates could alleviate the toxic response of plants to the co-pollution of TC and PS. This study enhances our understanding of the role of root exudates, providing insights for agricultural management and ensuring food safety.