Chemosphere最新文献

Regulatory authorities frequently need information on a chemical's capacity to produce acute systemic toxicity in humans. Due to concerns about animal welfare, human relevance, and reproducibility, numerous international initiatives have centered on finding a substitute for using animals in acute systemic lethality testing. These substitutes include the more current in-silico and in vitro techniques. Meanwhile, Advances in artificial intelligence and computational resources have led to a rise in the speed and accuracy of machine learning algorithms. Therefore, new approach methodologies (NAMs) based on in-silico modeling are considered a suitable place to start, even though many non-animal testing approaches exist for evaluating the safety of chemicals. Eventually, in this investigation, we have developed a hybrid computational model for acute inhalational toxicity data. In this case study, two major in silico techniques, QSAR (quantitative structure-activity relationship) and qRA (quantitative read-across) predictions, were utilized in a hybrid manner to extract more insightful information about the compounds based on similarity as well as the physicochemical properties. The findings of this investigation demonstrate that the integrated method surpasses the traditional QSAR model in terms of statistical quality for inhalational toxicity data, with greater predictability and transferability, due to a much smaller number of descriptors used in the hybrid modeling process. This hybrid modeling technique is a promising alternative, which can be paired with other methods in an integrated manner for a more rational categorization and evaluation of inhaled chemicals as a substitute for animal testing for regulatory purposes in the future.

Biofabricated selenium nanoparticles (Se-NPs) and sodium nitroprusside-derived nitric oxide (NO) singly or in combination was evaluated to improve tolerance to aluminum (Al) stress in rice (Oryza sativa L. cv. Swarna Sub1). The major objective was to elucidate contribution of sulfur reduction processes in oxidative stress tolerance along with cellular responses. Rice seedlings were primed against Al stress (550 μM) by the exogenous application of 100 μM NO and 20 ppm Se-NPs synthesized from a Salvinia molesta D. Mitch. extract. Green-synthesized Se-NPs (∼67 nm) had a crystalline, amorphous structure, high stability with functional groups in capping agents. The seedlings reduced bioaccumulation of Al in root tissues under SNP, Se-NPs, and in combination. Bioexclusion of Al was done in endodermal tissues by callose formation and binding in a fluorescent complex in the root tips. An upregulation of sulfur metabolism, including total sulfur, cysteine, cysteine synthase, and ATP sulfurylase activity was modulated by SNP + Se-NPs combination. Oxidative stress inducing metal stress for membrane oxidation into malondialdehyde, superoxide radical, and hydrogen peroxide, were also moderated by the SNP + Se-NPs combination. The Al-induced oxidative stress was relieved by a proportionate increase in superoxide dismutase and peroxidase activity. A higher ratio of ascorbate to dehydroascorbate and reduced to oxidized glutathione induced by the SNP + Se-NPs combination was supported antioxidation. These findings may substantiate the efficiency of green-synthesized Se-NPs together with SNP (as an NO donor) for amelioration of Al hazardous in crops like rice.

To determine the potentially detrimental impacts of short-chain chlorinated paraffins (SCCPs), we conducted assessments of acute effects on 96-h survival rate and biochemical markers, as well as chronic and multigenerational impacts on growth and reproduction over three generations in the marine mysid, Neomysis awatschensis. Dose-dependent increase of mortality was measured in both juvenile and adult mysids for 96 h. Exposure to the LC10 value (derived from the 96-h acute toxicity value) significantly reduced feeding activity in juveniles, accompanied by a significant elevation in oxidative stress and a reduction in acetylcholinesterase activity. When juvenile and adult mysids were exposed to 1/10 of the NOEC and NOEC values for four weeks, mortality significantly increased in juveniles. Furthermore, mysids subjected to constant exposure to 1/10 of the NOEC and NOEC values across three generations, F0-F2, displayed more pronounced growth retardation, an extended intermolt duration, and a reduced rate of reproduction. These results collectively indicate that even sublethal concentrations of SCCPs can have harmful effects on the health status of mysid populations when they are consistently exposed.

Soil is regarded as a natural repository for strongly adsorbed pollutants since glyphosate (GLY) is preferentially adsorbed by the inorganic fraction of the soil, which may greatly limits its leaching. In this way, understanding how clay mineralogy influences the sorption and transport processes of glyphosate in soils with different mineralogical characteristics is highly relevant. In this work, two clay mineralogy contrasting soils were used to evaluate GLY retention: a Oxisol (OX) with high levels of iron oxides (amorphous and crystalline) and a Inceptisol (IN) with a predominance of kaolinite. According to results obtained, the sorption process is influenced by more than one mechanism, including intraparticle diffusion, which is particularly favored at pH 4.00, and mass transfer across the boundary layer, which is favored at pH 6.50. When evaluating the adsorption isotherms, some differences associated with pH were also observed. At pH 4.00, good fits were obtained with the Freundlich model, suggesting electrostatic interaction between the compound and the soil. At pH 6.50, the best modeling involves the Langmuir-Freundlich model, indicating the occurrence of chemical and physical interactions. Desorption studies suggest that GLY sorption at pH 4.00 mostly involves the formation of inner-sphere complexes, while at pH 6.50, much of the sorption involves outer-sphere complexes. In column studies, GLY leaching was observed in both soils at concentrations between 0.01 and 0.02 mg L^-1. After pH correction by liming, differences were observed in the leached GLY concentration, especially in the second rain event in, which leached concentrations greater than 0.04 mg L^-1. These results confirm the strong sorption of GLY in the soil, as well as its evident mobilization through the soil column, probably due to colloid-facilitated transport.

The use of biocontrol microorganisms is one of the primary techniques used in agriculture to combat the damage caused by phytopathogens. Of these, Trichoderma sp. stand out as fungi species that are naturally present in agricultural soil and can come into contact with various compounds, such as nanostructured particles (NPs), which are starting to be used as pesticides and fertilizers. They can also enter the soil through various anthropogenic activities, such as water treatment, due to the treated water can then be used for crop irrigation. As a result, microorganisms like Trichoderma come into contact with these NPs, and it is unclear whether this will affect their growth and biocontrol ability. In order to determine whether the three adsorbent materials (magnetite (Fe₃O₄), Al-doped magnetite (Al-Fe₃O₄) and silver iron oxide (Ag_2-xFe _xO_4-x) NPs) are toxic or have an impact on the biocontrol activity, the goal of this work was to expose them to two species of Trichoderma. Finding that, at 100 ppm, Trichoderma grows successfully on Fe₃O₄ and Al-Fe₃O₄ but not in the presence of Ag_2-xFe _xO_4-x NPs. However, interestingly, the presence of these nanomaterials helps Trichoderma to better biocontrol two Fusarium species. In addition, Al-Fe₃O₄ and Ag_2-xFe _xO_4-x NPs affected the expression of mycoparasitism-associated genes. These results indicate that the use of these materials and their delivery to the environment would have a synergistic effect with Trichoderma to counteract phytopathogens of agricultural interest. Additionally, the synthesis, microstructural characterization and fluoride adsorption equilibrium of the Ag_2-xFe _xO_4-x NPs are presented.

Various commercial and industrial products widely use highly toxic eight-carbon-chain perfluorooctanesulfonate (PFOS), posing a significant threat to the health of living organisms. In this study, the electrochemical detection of PFOS was achieved by developing a carbon paste electrode (CPE) using the Mo₂Ti₂AlC₃ MAX phase. Mo₂Ti₂AlC₃ was synthesized and directly used to construct the CPE. The electrochemical performance of the prepared sensor was tested using various electrochemical techniques, such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV), and amperometric titration. The developed electrochemical sensor exhibited two linear ranges from 0.001 to 0.09 μM and from 1.1 to 62.6 μM, with a detection limit of 0.04 nM. The sensor demonstrated high sensitivity, measuring 145.1 μA μM^-1 cm^-2, and a response time of 5 s for PFOS quantification at a working potential of 0.3 V. Additionally, the sensor demonstrated outstanding resistance to typical interfering chemicals. The applicability and reliability of the developed sensor for PFOS determination were further tested in real samples, yielding recoveries in the range of 92.6-108.2%, with relative standard deviation (RSD) values between 1.8% and 3.7%. The Mo₂Ti₂AlC₃ MAX phase-based electrochemical sensor is simple, rapid, sensitive, and cost-effective, making it a promising approach for the quantification of PFOS in environmental water and soil samples.

The impact of artificial disintegration and re-granulation of anammox granules on the granule size, Extra-cellular Polymeric Substances (EPS) composition, microbial community characteristics, and the performance of the anammox process was investigated. Before the granule disintegration, the Dv50 and Granulation Index (GI) were 1280 μm and 54.62%, respectively. Following two cycles of disintegration and re-granulation process, these values shifted to 463 μm and 81.53%, respectively. This indicates that the disintegration and re-granulation process helped to form denser particles. The reduction in total EPS content and the increase in the PS/PN ratio of EPS well reflect these particle characteristics. Additionally, the disintegration and re-granulation process increased the dominance of Kuenenia Stuttgartiensis, which is well adapted to high salinity (2%) conditions, from 11.2% to 68.1%. By artificially disintegrating the granules and inducing re-granulation, it was possible to increase the dominance of specific anammox microorganisms with enhanced resilience of the anammox process.

Livestock and poultry breeding wastewater contains a large number of heavy metals and antibiotics; the volume is huge, and it is difficult to treat, which causes serious pollution of the environment. Some studies have shown that symbiotic systems can effectively improve the efficiency of sewage treatment, but there is still a lack of research on the treatment of livestock and poultry wastewater. This experiment not only provides a more in-depth discussion of previous studies, but also demonstrates the feasibility of symbiotic treatment of livestock and poultry wastewater and explores the survival mode and operation mechanism of algal and bacterial symbiosis. The results show that the presence of bacteria greatly promoted the growth of microalgae, with production of 0.50-0.59 g/L biomass and 17.5% lipid content. Lipid levels in the algae from the symbiotic system were 1.3 times higher than for the system of pure algae, which is attributed to the bacteria releasing extracellular substances to promote their own growth and providing small molecules of organic matter and other essential elements which can be used by microalgae. In addition, during the removal of complex pollutants in the symbiotic system we found that the main contributor to the removal of heavy metal ions was the adsorption by Chlorella, while the decomposition of antibiotics mainly originated from bacteria. Furthermore, in the context of this experiment was obtained the highest removal rate of SM2 reached 28.8%, while the removal rate of Cu(II) reached 60.6%-66.7%. The technology of symbiotic treatment of wastewater from livestock and poultry breeding fills a gap and lays a theoretical foundation for the improvement of wastewater treatment.

Environmental global changes are dramatically affecting agroecosystems. Insects have been shown to present various responses to multi-stress conditions (i.e., increase in temperature and exposure to contaminants). However, there is a knowledge gap on how temperature can modulate the hormetic effects in individuals sublethally exposed to chemical stressors. Here, we investigated how temperature (15, 20, 25, and 28 °C) modulates the effects of lethal and sublethal exposure to insecticides (imidacloprid) on the longevity, fecundity, and oxidative stress of a pest insect, the aphid Mysus persicae. Our results showed additive and interactive effects of temperature and insecticide on the stimulatory and oxidative responses of the insect pest. Overall, imidacloprid was 2.4-fold less toxic at 15 °C (3.547 μg/ml) than at 20 °C (1.482 μg/ml) and 24.6 to 19.8-fold less toxic than at 25 °C (0.144 μg/ml) and 28 °C (0.179 μg/ml) respectively. Furthermore, although the exposure of female aphids to most sublethal concentrations resulted in a decrease in their longevity and fecundity compared to the control, some of the sublethal concentrations produced positive effects in these parameters for the exposed individuals. The magnitude of induced sublethal effects varied between temperatures and occurred in similar ranges of low concentrations at temperatures 15 °C and 20 °C, and at temperatures 25 °C and 28 °C. Additionally, imidacloprid low concentrations induced a temperature-dependent production of reactive oxygen species in exposed insects at 12 and 24 h after exposure indicating oxidative stress. Our study supplies valuable data on how temperature modulates pesticide-mediated hormesis that can alter ecological interactions and functions within agroecosystems with potential implications in pest management.