Metal oxide nanoparticles facilitate the accumulation of bifenthrin in earthworms by causing damage to body cavity

Mixture toxicity study of two metal oxide nanoparticles and chlorpyrifos on Eisenia andrei earthworms

Co-exposure soil studies of pollutants are necessary for an appropriate ecological risk assessment. Here, we examined the effects of two-component mixtures of metal oxide nanoparticles (ZnO NPs or goethite NPs) with the insecticide chlorpyrifos (CPF) under laboratory conditions in short-term artificial soil assays using Eisenia andrei earthworms. We characterized NPs and their mixtures by scanning electron microscopy, atomic force microscopy, dynamic light scattering and zeta potential, and evaluated effects on metal accumulation, oxidative stress enzymes, and neurotoxicity related biomarkers in single and combined toxicity assays. Exposure to ZnO NPs increased Zn levels compared to control in single and combined exposure (ZnO NPs + CPF) at 72 h and 7 days, respectively. In contrast, there was no indication of Fe increase in organisms exposed to goethite NPs. One of the most notable effects on oxidative stress biomarkers was produced by single exposure to goethite NPs, showing that the worms were more sensitive to goethite NPs than to ZnO NPs. Acetylcholinesterase and carboxylesterase activities indicated that ZnO NPs alone were not neurotoxic to earthworms, but similar degrees of inhibition were observed after single CPF and ZnO NPs + CPF exposure. Differences between single and combined exposure were found for catalase and superoxide dismutase (goethite NPs) and for glutathione S-transferase (ZnO NPs) activities, mostly at 72 h. These findings suggest a necessity to evaluate mixtures of NPs with co-existing contaminants in soil, and that the nature of metal oxide NPs and exposure time are relevant factors to be considered when assessing combined toxicity, as it may have an impact on ecotoxicological risk assessment.

Effects of dissolved organic matter on the environmental behavior and toxicity of metal nanomaterials: A review

Metal nanomaterials (MNMs) have been released into the environment during their usage in various products, and their environmental behaviors directly impact their toxicity. Numerous environmental factors potentially affect the behaviors and toxicity of MNMs with dissolved organic matter (DOM) playing the most essential role. Abundant facts showing contradictory results about the effects of DOM on MNMs, herein the occurrence of DOM on the environmental process change of MNMs such as dissolution, dispersion, aggregation, and surface transformation were summarized. We also reviewed the effects of MNMs on organisms and their mechanisms in the environment such as acute toxicity, oxidative stress, oxidative damage, growth inhibition, photosynthesis, reproductive toxicity, and malformation. The presence of DOM had the potential to reduce or enhance the toxicity of MNMs by altering the reactive oxygen species (ROS) generation, dissolution, stability, and electrostatic repulsion of MNMs. Furthermore, we summarized the factors that affected different toxicity including specific organisms, DOM concentration, DOM types, light conditions, detection time, and production methods of MNMs. However, the more detailed mechanism of interaction between DOM and MNMs needs further investigation.

Unveiling combined ecotoxicity: Interactions and impacts of engineered nanoparticles and PPCPs

Emerging contaminants such as engineered nanoparticles (ENPs), pharmaceuticals and personal care products (PPCPs) are of great concern because of their wide distribution and incomplete removal in conventional wastewater and soil treatment processes. The production and usage of ENPs and PPCPs inevitably result in their coexistence in different environmental media, thus posing various risks to organisms in aquatic and terrestrial ecosystems. However, the existing literature on the physicochemical interactions between ENPs and PPCPs and their effects on organisms is rather limited. Therefore, this paper summarized the ecotoxicity of combined ENPs and PPCPs by discussing: (1) the interactions between ENPs and PPCPs, including processes such as aggregation, adsorption, transformation, and desorption, considering the influence of environmental factors like pH, ionic strength, dissolved organic matter, and temperature; (2) the effects of these interactions on bioaccumulation, bioavailability and biotoxicity in organisms at different trophic levels; (3) the impacted of ENPs and PPCPs on cellular-level biological process. This review elucidated the potential ecological hazards associated with the interaction of ENPs and PPCPs, and serves as a foundation for future investigations into the ecotoxicity and mode of action of ENPs, PPCPs, and their co-occurring metabolites.

Butyl benzyl phthalate exposure impact on the gut health of Metaphire guillelmi

Agricultural films are extensively utilized in high-intensity agriculture, with China's annual usage reaching 1.5 million tons. Unfortunately, the recovery rate is less than 60%, leading to an inevitable accumulation of plastic mulch in agricultural soils. This accumulation primarily introduces butyl benzyl phthalate (BBP) into soil ecosystems, whose specific effects remain largely unclear, thereby posing potential risks. The present study focuses on the exposure impact of BBP on earthworms, Metaphire guillelmi, a commonly found endogenic earthworm within real farmland, as it provides insight into the direct interaction between biota gut health and contaminants. Specifically, we studied the biomarkers related to oxidative stress, the digestive system, and neurotoxicity within the gut of Metaphire guillelmi, and the integrated biological response (IBR) index was utilized to track these markers at different timeframes after BBP exposures. Our findings indicate that BBP exposures lead to oxidative damage, digestive system inhibition, and neurotoxicity, with IBR indexes of 14.6 and 17.3 on the 14th and 28th days, respectively. Further, the underlying mechanisms at a molecular level through molecular docking were investigated. The results showed that the most unstable interaction was with the Na+K+-ATPase (binding energy: -2.25 kcal-1), while BBP displayed stable bonds with superoxide dismutase and 8-hydroxydeoxyguanosine via hydrogen bonds and hydrophobic interaction. These interactions resulted in changes in protein conformation and their normal physiological functions, offering new insights into the molecular mechanism underlying enzymatic activity changes. This study has significant implications for the prediction of toxicity, environmental risk assessment, and the establishment of regulations related to BBP.

The effect of TiO2NPs on cloransulam-methyl toxicity to earthworm (Eisenia fetida)

Cloransulam-methyl is a new herbicide and has broad application prospect. However, the effect of cloransulam-methyl on earthworm have yet to be clarified. As more and more titanium dioxide nanoparticles (TiO₂NPs) enter the soil, cloransulam-methyl and TiO₂NPs have a risk of co-exposure, but the effect of TiO₂NPs on cloransulam-methyl toxicity is unknown. In the study, the ecotoxicity of cloransulam-methyl (0.1, 1 mg kg^-1) on earthworm and the effect of TiO₂NPs (10 mg kg^-1) on cloransulam-methyl toxicity was investigated after exposure for 28 and 56 d. Exposure tests showed cloransulam-methyl and cloransulam-methyl + TiO₂NPs promoted the accumulation of reactive oxygen species, malondialdehyde and 8-hydroxydeoxyguanosine, increased the activities of superoxide dismutase and catalase, resulted in lipid peroxidation and DNA damage. Besides, the results at the genetic level showed cloransulam-methyl and cloransulam-methyl + TiO₂NPs altered the expression of physiologically-related genes, which demonstrated that cloransulam-methyl and cloransulam-methyl + TiO₂NPs induced oxidative stress and cell apoptosis, and disturbed the normal reproduction in earthworm. The results of comprehensive toxicity comparison indicated cloransulam-methyl and TiO₂NPs co-exposure has higher toxicity compared to cloransulam single exposure. Our results suggest that TiO₂NPs can enhance the toxicity of cloransulam-methyl on Eisenia fetida in terms of oxidative stress, cell apoptosis and reproduction aspects. Based on above studies, it is of great importance for evaluating the risk of cloransulam-methyl co-exposure with TiO₂NPs in soil.

Effects of ecotoxicity of penoxsulam single and co-exposure with AgNPs on Eisenia fetida

Penoxsulam (PNX) and silver nanoparticles (AgNPs) are likely to coexist in soils due to continuous use. However, the ecotoxicity of PNX in earthworms and the effect of AgNPs on PNX toxicity are unknown. Therefore, the toxicity of PNX (0.05, 0.5, and 2.5 mg/kg) single and co-exposure with AgNPs (10 mg/kg) after 28 and 56 days on Eisenia fetida (E. fetida) was investigated from biochemical, genetic, histopathological, and transcriptomic aspects. The results showed that the low concentration of PNX (0.05PNX) had almost no effect on the biochemical level of E. fetida. However, the addition of AgNPs resulted in 0.05PNX causing E. fetida to produce excessive reactive oxygen species, and the activity of antioxidant and detoxification enzymes were interfered, resulting in lipid peroxidation and DNA damage. From the genetic level, even the lowest concentration of PNX can significantly interfere with the expression of functional genes, thus inducing oxidative stress and apoptosis and inhibited reproductive behavior in E. fetida. The integrated biomarker response results at the biochemical and genetic levels showed that the comprehensive toxicity of PNX and PNX + AgNPs on E. fetida was PNX dose-dependent. And the toxicity of all co-exposure groups was greater than that of the PNX only exposure groups. Furthermore, the addition of AgNPs significantly increased the damage of PNX on E. fetida intestinal tissue. Meanwhile, transcriptomic analysis showed that PNX + AgNPs had a greater effect on E. fetida than PNX single, and multiple pathways related to oxidative stress, inflammation, and cellular process regulation were disturbed. These results provide a basis for comprehensive evaluation of the ecotoxicity of PNX and confirm that the AgNPs does increase the ecotoxicity of PNX in soil environment.

Commonwealth of Soil Health: How Do Earthworms Modify the Soil Microbial Responses to CeO2 Nanoparticles?

Soil ecotoxicological assays on nanoparticles (NPs) have mainly investigated single components (e.g., plants, fauna, and microbes) within the ecosystem, neglecting possible effects resulting from the disturbance of the interactions between these components. Here, we investigated soil microbial responses to CeO₂ NPs in the presence and absence of earthworms from the perspectives of microbial functions (i.e., enzyme activities), the community structure, and soil metabolite profiles. Exposure to CeO₂ NPs (50, 500 mg/kg) alone decreased the activities of enzymes (i.e., acid protease and acid phosphatase) participating in soil N and P cycles, while the presence of earthworms ameliorated these inhibitory effects. After the CeO₂ NP exposure, the earthworms significantly altered the relative abundance of some microbes associated with the soil N and P cycles (Flavobacterium, Pedobacter, Streptomyces, Bacillus, Bacteroidota, Actinobacteria, and Firmicutes). This was consistent with the pattern found in the significantly changed metabolites which were also involved in the microbial N and P metabolism. Both CeO₂ NPs and earthworms changed the soil bacterial community and soil metabolite profiles. Larger alterations of soil bacteria and metabolites were found under CeO₂ NP exposure with earthworms. Overall, our study indicates that the top-down control of earthworms can drastically modify the microbial responses to CeO₂ NPs from all studied biological aspects. This clearly shows the importance of the holistic consideration of all soil ecological components to assess the environmental risks of NPs to soil health.

Impacts of polyethylene microplastics on bioavailability and toxicity of metals in soil

In this study, we investigated the bioavailability and toxicity of metals (Cu and Ni) in the soil containing polyethylene microplastics (PE-MPs). The bioavailability of the metals determined by the five-step chemical sequential extraction method increased with the addition of MPs (0.1%, 1%, 10%) in the soil, which was confirmed by the adsorption-desorption characteristics. To further examine the bioavailability and toxicity of metals, earthworms (Eisenia fetida) were exposed to soil containing Cu²⁺ (100 mg/kg) or Ni²⁺ (40 mg/kg) with different amounts (0.01%, 0.05%, and 0.1%) of PE-MPs for 21 days. The highest concentrations of Cu²⁺ and Ni²⁺ in earthworms reached to 73.3 and 36.3 mg/kg, respectively. Moreover, metal concentrations in earthworms increased with MP contents in the soil, which was consistent with the bioavailability measured by the sequential extraction method. Furthermore, changes in biomarkers including peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) activity, malondialdehyde (MDA) contents, and related gene expression levels in earthworms suggested that the pollutants caused toxicity to earthworms. Overall, MPs increased the bioavailability of metals in the soil and the toxic effects to earthworms. These findings provide insights regarding the impacts of MPs on the bioavailability of metals and the combined toxic effects of these two kinds of pollutants on terrestrial animals.

Size effects of microplastics on accumulation and elimination of phenanthrene in earthworms

Microplastics (MPs) are a class of emerging contaminants with diverse sizes. They influence the behavior of pollutants in the environment and cause harmful effects on organisms. To date, the size effects of MPs on the accumulation of organic pollutants by terrestrial invertebrates remain unclear. Here, we study the impacts and mechanisms of polystyrene MPs on the accumulation and elimination of phenanthrene in earthworms. Results showed that larger-size MPs (10 and 100 µm) facilitated the accumulation of phenanthrene by earthworms in the first week, whereas 100 nm MPs inhibited the elimination of phenanthrene in earthworms afterwards. Higher genotoxicity to earthworms was observed for co-exposure of micron-size MPs and phenanthrene, and 10 µm MPs were detected at the highest concentration and caused the most serious DNA damage to earthworm coelomocytes. Biomarkers and their mRNA gene expression levels suggested that larger-size MPs caused severer damage to earthworms, thus leading to increased accumulation of phenanthrene by earthworms at the beginning. Moreover, high-throughput 16S rRNA gene sequencing indicated that nano-size MPs significantly inhibited phenanthrene-degrading bacteria in earthworms, resulting in the highest residual concentration of phenanthrene. This study highlights the size effects of MPs and their impacts on the accumulation of organic pollutants by terrestrial organisms.

Insights into the mechanisms underlying the remediation potential of earthworms in contaminated soil: A critical review of research progress and prospects

In recent years, soil pollution is a major global concern drawing worldwide attention. Earthworms can resist high concentrations of soil pollutants and play a vital role in removing them effectively. Vermiremediation, using earthworms to remove contaminants from soil or help to degrade non-recyclable chemicals, is proved to be an alternative, low-cost technology for treating contaminated soil. However, knowledge about the mechanisms and framework of the vermiremediation various organic and inorganic contaminants is still limited. Therefore, we reviewed the research progress of effects of soil contaminants on earthworms and potential of earthworm used for remediation soil contaminated with heavy metals, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), pesticides, as well as crude oil. Especially, the possible processes, mechanisms, advantages and limitations, and how to boost the efficiency of vermiremediation are well addressed in this review. Finally, future prospects of vermiremediation soil contamination are listed to promote further studies and application of vermiremediation in contaminated soils.

Nanoparticles in Agroindustry: Applications, Toxicity, Challenges, and Trends

Nanotechnology is a tool that in the last decade has demonstrated multiple applications in several sectors, including agroindustry. There has been an advance in the development of nanoparticulated systems to be used as fertilizers, pesticides, herbicides, sensors, and quality stimulants, among other applications. The nanoencapsulation process not only protects the active ingredient but also can affect the diffusion, interaction, and activity. It is important to evaluate the negative aspects of the use of nanoparticles (NPs) in agriculture. Given the high impact of the nanoparticulated systems in the agro-industrial field, this review aims to address the effects of various nanomaterials on the morphology, metabolomics, and genetic modification of several crops.