Chronic toxicity effects of sediment-associated polystyrene nanoplastics alone and in combination with cadmium on a keystone benthic species Bellamya aeruginosa

DNA damage and molecular level effects induced by polystyrene (PS) nanoplastics (NPs) after Chironomus riparius (Diptera) larvae

Graphene oxide (GO) features distinctive physical and chemical characteristics; therefore, it has been intensively investigated in environmental remediation as a promising material for clean-up of soil contamination and water purification and used as immobilization material. Plastic is a widespread pollutant, and its breakdown products such as nanoplastics (NPs) should be evaluated for potential harmful effects. This study is aimed to evaluate the influence of GO on the toxicity of polystyrene (PS) NPs to the marine microalgae Picochlorum sp. over a period of 4weeks. The capability of GO to reduce the toxic effects of PS NPs was assessed through investigating exposure sequence of GO in the presence of 20nm diameter-sized polystyrene NPs. This was accomplished through five test groups: microalgae pre-exposed to GO prior to incubation with PS NPs, microalgae post-exposed to GO after incubation with PS NPs, microalgae simultaneously exposed to GO and PS NPs, and individual exposure of microalgae to either GO or PS NPs. Cytotoxicity assay results demonstrated that microalgae pre-exposed to GO prior to incubation with PS NPs showed an increased viability and chlorophyll a content. The pre-exposure to GO has reduced the growth inhibition rate (IR) from 50%, for microalgae simultaneously exposed to GO and PS NPs, to 26%, for microalgae pre-exposed to GO. Moreover, the lowest level of reactive oxygen species (ROS) was recorded for microalgae exposed to GO only and microalgae pre-exposed to GO. Fourier-transform infrared (FTIR) analysis, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) observations revealed some morphological changes of both algae and their extracellular polymeric substances (EPS) upon GO and PS NPs exposure combinations. The sequence of GO exposure to aquatic microorganisms might affect the level of harm caused by the PS NPs. Therefore, application of GO as part of an immobilization material and in the removal of pollutants from water should be carefully investigated using different pollutants and aquatic organisms.

Clay minerals limit nanoplastic uptake in wheat plant.

Nanoplastics (NPs) and cadmium (Cd) coexist in soil, but the combined effects of NPs and Cd on the rhizosphere bacterial community remain unknown. In this study, high-throughput sequencing and PICRUSt2 functional analysis were employed to explore the individual and combined effects of polystyrene (PS) NPs (low concentration [N1, 100 mg·kg-1] and high concentration [N2, 1000 mg·kg-1]) and Cd (low concentration [C1, 0.6 mg·kg-1] and high concentration [C2, 4 mg·kg-1]) on the diversity, structural composition, and function of the rhizosphere bacterial community associated with Sedum alfredii Hance. Individually, PS NPs and Cd significantly reduced the soil pH, while the combined treatments induced a more significant decrease in pH. In contrast, combined PS NPs and Cd significantly increased the diethylenetriaminepentaacetic acid-Cd (DTPA-Cd) and total Cd concentrations. Compared with individual treatments, C2N2 significantly increased DPTA-Cd by 4.08%. N1 had no significant effect on the Chao1, observed species, or Shannon indices, while N2 significantly reduced the richness and diversity of the rhizosphere bacteria and altered their community structure. Furthermore, adding PS NPs exacerbated the effect of Cd on rhizosphere bacterial communities. Compared with individual Cd treatments, C2N2 significantly reduced the relative abundances of Actinobacteriota, Bacteroidota, Crenarchaeota, and Myxococcota by 19.76%, 2.01%, 1.49%, and 2.00%, respectively, and significantly increased the relative abundance of Acidobacteriota by 16.05%. A cluster heat map showed that the combined treatments attenuated glycan biosynthesis and metabolic function and enhanced the metabolism of cofactors and vitamins. These findings illuminate rhizosphere processes under co-contamination with heavy metals and PS NPs, supporting the practical application of phytoremediation to alleviate combined Cd and PS NP pollution.

The fate and toxicity of nanoplastics (NPs) in the environment is largely determined by their stability. We explored how water composition, nanoplastic size, and surface carboxyl group density influenced the aggregation of polystyrene (PS) NPs in fresh water. Unfunctionalized 200, 300, 500, and 1000nmPS NPs and 310nm carboxylated PS NPs with carboxyl group densities of 0.35 and 0.6mmolg-1 were used to simulate pristine and aged NPs. Natural water matrices tested in this study include synthetic surface water (SSW), water from the Schie canal (Netherlands) and tap water. Suwannee River Natural Organic Matter (SRNOM) was included to mimic organic matter concentrations. In CaCl2, we found PS NPs are more stable as their size increases with the increase of the critical coagulation concentration (CCC) from 44mM to 59mM and 77mM for NP sizes of 200nm, 300nm and 500nm. Conversely, 1000nmPS NPs remained stable even at 100mM CaCl2. Increasing the carboxyl group density decreased the stability of NPs as a result of the interaction between Ca2+ and the carboxyl group. These results were consistent with the mass of Ca2+ adsorbed per mass of NPs. The presence of SRNOM decreased the stability of PS NPs via particle bridging facilitated by SRNOM. However, in SSW, Schie water and tap water with low divalent cation concentrations, the hydrodynamic size of PS NPs did not change, even at prolonged durations up to one week. We concluded that PS NPs are unlikely to aggregate in water with low divalent cation concentrations, like natural freshwater bodies. Ecotoxicologists and water treatment engineers will have to consider treating PS NPs as colloidally stable particles as the lack of aggregation in fresh surface water bodies will affect their ecotoxicity and may pose challenges to their removal in water treatment.

Hydrophobicity-driven self-assembly of nanoplastics and silver nanoparticles for the detection of polystyrene microspheres using surface enhanced Raman spectroscopy

Exposure to polystyrene nanoplastics induces an anxiolytic-like effect, changes in antipredator defensive response, and DNA damage in Swiss mice.

Combined effects of bacteria and antibiotics on surface properties and transport of nanoplastics in porous media

Extraction and quantification of polystyrene nanoplastics from biological samples

Nanoplastics (NPs) are plastic particles with a size of less than 1μm, and they have the potential to enter the human body through the food chain. In the context of climate change, the combined effects of global warming and NPs on surrounding ecosystems remain largely understudied. Therefore, this study analyzed the impact of temperature increase under laboratory conditions and NPs exposure on plant germination and early growth of radish (Raphanus sativus L.) Radish seeds were placed onto petri dishes and PS NPs (polystyrene nanoplastics) were added. The PS NPs that are 100, 200, and 400 nm in diameter were applied at 0, 100, 500, and 1000 mg L-1. To simulate different climate change scenarios, these seeds were incubated in chambers set to temperatures of ambient, approx. 22℃, ambient +3℃, and ambient +6℃ in consideration of the germination temperature of radish. The experimental period was 8 days in total, and the germination rate was measured three times every 24 hours, and the root length and diameter were measured on the 8th day. PS NPs treatment increased the root growth of radish under the treatment of 100- and 200-nm PS NPs. The root length of radish was the longest under 200-nm PS NPs treatment, whereas the root diameter was the thickest under 100-nm PS NPs treatment, respectively. Temperature had a significant effect on the germination rate on day 1, and the germination rate was the lowest at 1000 mg L-1 of 100-nm and 100 mg L-1 of 400-nm PS NPs treatments at ambient + 3℃. Under 1000 mg L-1 of 100-nm PS NPs treatment, this trend lasted until day 3. The promotion or inhibition of crop growth due to NPs treatment may vary depending on the size and concentration of specific NPs, and the impact of NPs on seed germination and early growth of root crop is considered to differ due to various factors. We analyzed the effects of climate change and NPs on radish and discovered that germination rates and initial growth responses vary depending on different environmental factors in this study. Our finding is expected to contribute to assessing the risks associated with NPs pollution under rising temperatures associated with climate change and to establishing criteria for evaluating soil ecosystem health.

Nano-plastics (NPs) have emerged as a significant environmental pollutant, widely existing in water environment, and pose a serious threat to health and safety with the intake of animals. Skeletal muscle, a vital organ for complex life activities and functional demands, has received limited attention regarding the effects of NPs. In this study, the effects of polystyrene NPs (PS-NPs) on skeletal muscle development were studied by oral administration of different sizes (1mg/kg) of PS-NPs in mice. The findings revealed that PS-NPs resulted in skeletal muscle damage and significantly hindered muscle differentiation, exhibiting an inverse correlation with PS-NPs particle size. Morphological analysis demonstrated PS-NPs caused partial disruption of muscle fibers, increased spacing between fibers, and lipid accumulation. RT-qPCR and western blots analyses indicated that PS-NPs exposure downregulated the expression of myogenic differentiation-related factors (Myod, Myog and Myh2), activated PPARγ/LXRβ pathway, and upregulated the expressions of lipid differentiation-related factors (SREBP1C, SCD-1, FAS, ACC1, CD36/FAT, ADIPOQ, C/EBPα and UCP-1). In vitro experiments, C2C12 cells were used to confirm cellular penetration of PS-NPs (0, 100, 200, 400μg/mL) through cell membranes along with activation of PPARγ expression. Furthermore, to verify LXRβ as a key signaling molecule, silencing RNA transfection experiments were conducted, resulting in no increase in the expressions of PPARγ, LXRβ, SREBP1C, FAS, CD36/FAT, ADIPOQ, C/EBPα and UCP-1 even after exposure to PS-NPs. However, the expressions of SCD-1and ACC1 remained unaffected. The present study evidenced that exposure to PS-NPs induced lipid accumulation via the PPARγ/LXRβ pathway thereby influencing skeletal muscle development.

Short term exposure to polystyrene nanoplastics in mice evokes self-regulation of glycolipid metabolism

Effects of inorganic ions and natural organic matter on the aggregation of nanoplastics

Development of hydroxyapatite-enhanced membrane for nanoplastics removal: Multiple scenarios and mechanism exploration.

Metagenomic insight into the enrichment of antibiotic resistance genes in activated sludge upon exposure to nanoplastics