Toxics最新文献

Rice is the main source of cadmium (Cd) and arsenic (As) in Chinese diet. The formulation of targeted agronomic interventions for mitigating Cd and As bioaccumulation in rice grains constitutes a critical pathway toward ensuring food safety and public health security. Foliar spraying technology with ionic liquids, effectively reduces Cd/As content in rice. In this study, an ionic liquid of amino acids ([Glu][H₂PO₄]) as a foliar conditioner was applied to two varieties of rice (X24 and Z35) to explore the mechanism of reducing the accumulation of Cd/As in rice. The results showed that [Glu][H₂PO₄] reduced Cd/As levels by up to 58.57% and 44.09%, respectively. [Glu][H₂PO₄] reduced the transfer factor from the root system to flag leaves, nodes, and other organs, thus reducing the Cd/As content in them. [Glu][H₂PO₄] promoted amino acid synthesis in seeds, increased Ca²⁺ level, increased OsGLR3.1-3.5 expression, and decreased OsLsi1-3 expression in flag leaves, thereby Cd/As was inhibited from being absorbed and transported by rice. The results demonstrated that the foliar application of [Glu][H₂PO₄] significantly mitigated the accumulation of Cd/As in rice. This study introduces a novel and effective strategy for reducing Cd/As accumulation in rice, hoping to enhance the safety and quality of rice crops.

Aquaculture wastewater treatment not only assists in alleviating the scarcity of clean water for daily usage and environmental pollution, but also generates valuable byproducts. This paper aims to review the generation of wastewater from the aquaculture sector, its characteristics, and available treatment technologies, while comprehensively discussing the adoption of a biocircular economy approach through waste valorization. With rich nutrients, such as nitrogenous compounds, and the presence of phosphorus in the aquaculture effluent, these aspects could be explored and valorized into biofertilizers, broadening their application in aquaponics and hydroponics, as well as in algae and daphnid cultivation. Biofertilizer can also be used in agriculture because it contains essential elements needed by plants. Thus, methods of converting nutrients into biofertilizers in terms of sludge recovery can be accomplished via anaerobic and aerobic digestion, drying, composting, and vermicomposting. Moving forward, aquaculture effluent recovery is addressed under the biocircular economy by re-engaging aquaculture wastewater effluents into the production cycle. The enhancement of aquaculture effluents and biomass for uses such as aquaponics, hydroponics, algae cultivation, daphnid co-cultivation, and biofertilizers presents valuable opportunities for nutrient recovery while ensuring that non-toxic wastewater can be safely discharged into external water bodies. This approach has the potential to revolutionize wastewater treatment in aquaculture, shifting the economic model of wastewater management from a linear system to a circular, more sustainable one.

Over the past century, human activities have profoundly transformed global ecosystems. Lake Victoria in East Africa exemplifies these challenges, showcasing the interplay of anthropogenic pressures driven by land use changes, urbanization, agriculture, and industrialization. Our comprehensive study investigates polycyclic aromatic hydrocarbons (PAHs) and n-alkanes in the lake and its catchment to trace their sources and historical deposition. Sediment cores were collected from six sites within the catchment, representing diverse landforms and human activities, ensuring a comprehensive understanding of the basin. The results indicate significant spatial and temporal variations in both PAH and n-alkane profiles, reflecting diverse land use changes and development trajectories in the basin. Urban sites often exhibited higher concentrations of PAHs and short-chain n-alkanes, indicative of anthropogenic sources such as fossil fuel combustion, the input of petroleum hydrocarbons, and industrial emissions. In contrast, rural areas showed low PAH levels and a dominance of long-chain n-alkanes from terrestrial plant waxes. The n-alkane ratios, including the Carbon Preference Index and the Terrigenous-Aquatic Ratio, suggested shifts in organic matter sources over time, corresponding with land use changes and increased human activities. A mid-20th century shift toward increased anthropogenic contributions was observed across sites, coinciding with post-independence development. The mid-lake sediment core integrated inputs from multiple sub-catchments, providing a comprehensive record of basin-scale changes. These findings highlight three distinct periods of organic matter input: pre-1960s, dominated by natural and biogenic sources; 1960s-1990s, marked by increasing anthropogenic influence; and post-1990s, characterized by complex mixtures of pyrogenic, petrogenic, and biogenic sources. This study underscores the cumulative environmental and aquatic ecosystem effects of urbanization (rural vs. urban sites), industrialization, and land use changes over the past century. The combined analyses of PAHs and n-alkanes provide a comprehensive understanding of historical and ongoing environmental impacts, emphasizing the need for integrated management strategies that address pollutant inputs to preserve Lake Victoria's ecological integrity.

The increasing presence of antimicrobial agents and pesticides in aquatic environments raises concerns about their potential impacts on non-target organisms. Among these chemicals, deltamethrin (DM), a widely used pesticide, and sulfamethoxazole (SMX), an antimicrobial commonly detected in water bodies, pose significant ecological risks. This study investigates the acute toxicity, neurotoxic effects, oxidative stress responses, immune-related gene expression, and feeding behavior of adult zebrafish exposed to DM and SMX. The 96 h LC₅₀ for DM was 4.84 µg/L, indicating significant acute toxicity, while the LC₅₀ for the DM + SMX mixture was 11.32 µg/L, suggesting that SMX may mitigate the toxicity of DM. Neurotransmitter alterations, including reduced levels of γ-aminobutyric acid (γ-GABA), serotonin (5-HT), and acetylcholinesterase (AChE), were observed, with the combination of DM and SMX showing partial restoration of AChE activity. Oxidative stress markers revealed significant changes in antioxidant enzyme activities, with DM exposure increasing superoxide dismutase (SOD) and glutathione-S-transferase (GST) activities, while decreasing catalase (CAT) and glutathione peroxidase (GPX) activities. Immune-related gene expression demonstrated suppressed IgM, IgD, and IgZ levels, along with altered inflammatory responses, with both DM and DM + SMX exposure inducing pro-inflammatory cytokines. Finally, feeding behavior was significantly impaired in the DM group at the 3 min mark, while the DM + SMX group showed partial mitigation of this effect. These findings highlight the neurotoxic, immunotoxic, and behavioral effects of DM and SMX, and underscore the potential for chemical interactions to modulate toxicity in aquatic organisms.

Cadmium (Cd) is an important environmental pollutant that can enter the body and inflict kidney damage. Quercetin (Que) is a natural flavonoid compound that can alleviate kidney damage in Cd-treated rats, but the specific mechanism is unclear. Herein, 24 male Sprague-Dawley rats were divided into four groups, namely the control, Cd, Cd + Que, and Que groups. Four weeks later, the rats were anesthetized with ether and were euthanized; then, their blood was collected and their kidneys were removed. Renal function markers were measured. Kidney tissue structure was observed by HE staining, cell apoptosis was detected by the TUNEL method, and mRNA and protein expression levels in the IRE1α-XBP1 apoptosis signaling pathway were analyzed by RT-PCR and Western blotting. Results showed that the Cd treatment group exhibited decreased renal dysfunction and pathologic injury. Cd-induced tissue damage and cell apoptosis and significantly increased the mRNA and protein expression levels (p < 0.01) related to the IRE1α-XBP1 signaling pathway. Compared with the Cd group, the Cd + Que group exhibited increased renal dysfunction. Conversely, kidney tissue damage and renal cell apoptosis decreased, and the mRNA and protein expression levels of IRE1α and XBP1 significantly decreased (p < 0.01). Cd treatment inflicted renal damage. Therefore, Que can restore the kidney tissue damage and alleviate the cell apoptosis caused by Cd through the inhibition of the IRE1α-XBP1 signaling pathway.

Biochar can stabilize heavy metals in soil and inhibit their accumulation in plants as a soil amendment. Sepiolite has also shown good effects in the remediation of soil heavy metal pollution. In this study, biochar, sepiolite, and biochar-sepiolite combined amendments were used to evaluate the accumulation of cadmium (Cd) and lead (Pb) in soil by 29 corn varieties. The concentrations of Cd and Pb in corn fruits were the lowest (Pb: 0.11 mg/kg, Cd: 0.06 mg/kg). There was a significant difference (p < 0.05) in Pb and Cd accumulation in the roots, stems, leaves, and fruits in the 29 corn varieties. The BCF and TF values of Pb and Cd in the 29 corn varieties were different, and Pb is more likely to accumulate in the roots, Cd is more likely to accumulate in the leaves, and neither heavy metal is easily translocated to the corn fruits. The combination of biochar and sepiolite creates an environment conducive to the retention of heavy metals in the root zone, effectively reducing the risk of heavy metal contamination in the edible parts of the plants. After considering various factors, such as environmental adaptability, we recommend using sepiolite and biochar combined as a soil amendment material and planting the WG1790 variety. Field experiments are needed to verify the effects. These results provide scientific evidence and new strategies for the selection of corn varieties and soil amendments.

N, N-Dimethylaniline is an important chemical intermediate and an important metabolite of the pesticide Fenaminosulf. It is widely used in chemical production, but there is an extreme paucity of environmental risk assessments for N, N-dimethylaniline.: In this study, the cardiotoxicity of continuous exposure to N, N-dimethylaniline (20, 40, and 80 μg/mL) for 72 h was evaluated using zebrafish embryos.: The study found that N, N-dimethylaniline not only exhibits developmental toxicity to zebrafish embryos, leading to abnormalities such as pericardial edema, yolk sac edema, and spinal curvature, but also induces oxidative stress, lipid accumulation, and apoptosis, particularly affecting the heart region. Cardiac function indicators such as pericardial area, sinus venosus (SV) and bulbar artery (BA) distance, heart rate, and red blood cell (RBC) rate were all significantly altered due to exposure to N, N-dimethylaniline, with impaired cardiac morphology and structure and the downregulation of gene expression related to heart development and function (myl7, vmhc, myh6, bmp4, tbx2b, and has2).: The research findings suggest that the heart may be the potential target organ for the toxic effects of N, N-dimethylaniline, providing a scientific basis for the rational use of this compound and environmental protection. Furthermore, it enhances public awareness of the safety of substances that may degrade to produce N, N-dimethylaniline during their use.

(1) Objective: To evaluate the relationship between fluoride exposure, interactions of BMP2/BMP4 gene polymorphisms, and fluoride exposure on essential hypertension. (2) Methods: A cross-sectional study was conducted among 725 participants in a high-fluoride region of Shanxi Province, China. Urinary fluoride concentrations were measured as indicators of fluoride exposure. Hypertension was diagnosed based on standard guidelines. BMP2 (rs1005464) and BMP4 (rs17563) polymorphisms were genotyped. Logistic regression and interaction models were performed to evaluate associations and interactions between fluoride exposure, gene polymorphisms, and hypertension. (3) Results: Higher urinary fluoride concentrations were significantly associated with an increased risk of hypertension, exhibiting a dose-dependent relationship. The rs1005464 (G > A) polymorphism of BMP2 was identified as a protective factor against hypertension in individuals with the AG + AA genotype. Significant interactions were observed between the BMP2 rs1005464 and BMP4 rs17563 polymorphisms, influencing hypertension risk. Additionally, both multiplicative and additive interactions between high fluoride exposure and the BMP4 rs17563 polymorphism were identified, highlighting the combined impact of environmental and genetic factors on hypertension. (4) Conclusions: Fluoride exposure is positively associated with hypertension. BMP2 gene polymorphisms affect the risk of hypertension, and BMP4 gene polymorphisms may modify the impact of fluoride on hypertension.

PM_2.5 and volatile organic compounds (VOCs) have been identified as the primary air pollutants affecting the Fenwei Plain (FWP), necessitating urgent measures to improve its air quality. To gain a deeper understanding of the formation mechanisms of these pollutants, this study employed various methods such as HYSPLIT, PCT, and PMF for analysis. Our results indicate that the FWP is primarily impacted by PM_2.5 from the southern Shaanxi air mass and the northwestern air mass during winter. In contrast, during summer, it is mainly influenced by O₃ originating from the southern air mass. Specifically, high-pressure fronts are the dominant weather pattern affecting PM_2.5 pollution in the FWP, while high-pressure backs predominately O₃ pollution. Regarding the sources of PM_2.5, secondary nitrates, vehicle exhausts, and secondary sulfates are major contributors. As for volatile organic compounds, liquefied petroleum gas sources, vehicle exhausts, solvent usage, and industrial emissions are the primary sources. This study holds crucial scientific significance in enhancing the regional joint prevention and control mechanism for PM_2.5 and O₃ pollution, and it provides scientific support for formulating effective strategies for air pollution prevention and control.

Nitroaromatic compounds (NACs) have adverse effects on human health and climate. Daily PM_2.5 samples were collected in winter and summer of 2022 in two cities, Chengdu (CD) and Mianyang (MY), located in Sichuan Basin of southwestern China. Four types of NACs in PM_2.5, containing nitrophenols, nitrocatechols, nitrosalicylic acids, and nitronaphthol, were analyzed. The mean concentration of a total of 10 NACs (ΣNACs) in winter at the suburban MY site (71.7 ± 35.6 ng m^-3) was higher than that in urban CD (29.5 ± 16.2 ng m^-3), while in summer, the mean concentrations of ΣNACs in the two cities were similar, around 2.2 ng m^-3. The much higher concentrations of ΣNACs in winter were attributed to the impact of biomass burning. 4-Nitrocatechol (4NC) was the most abundant species during the sampling period, accounting for 35-56% of ΣNACs mass. In winter, the mean light absorption coefficient of methanol-soluble brown carbon (Abs_365,M) was 10.5 ± 3.4 and 13.6 ± 4.3 Mm^-1 in CD and MY, respectively, which was about 4-7 times that of summer. The contributions of light absorption of ΣNACs at 365 nm to Abs_365,M were 1.6-3.6% in winter and 0.5-0.7% in summer, with 4NC contributing the most to brown carbon among all NACs. The geographical origins of potential sources of NACs at both sites were mainly distributed within the basin.