Journal of Environmental Science and Health Part B-pesticides Food Contaminants and Agricultural Wastes最新文献

The increased use of pesticides in tropical regions, combined with rapid warming due to climate change, poses a critical threat to amphibian populations. However, the interactive effects of these stressors on tropical amphibians remain poorly understood. In this study, we assessed lethal and sublethal responses to methomyl in two Amazonian anurans, Osteocephalus taurinus and Scinax ruber. Tadpoles were exposed to methomyl at two temperatures (26.5 °C and 30 °C), simulating current and projected climate scenarios. Acute toxicity was quantified through LC₅₀, and thermal tolerance was assessed via critical thermal maximum (CT_max). Warming significantly increased methomyl toxicity in O. taurinus, lowering the LC₅₀ from 96.4 mg/L to 45.9 mg/L at 30 °C. S. ruber showed no such effect, with LC₅₀ values of 15.5 mg/L (26.5 °C) and 19.7 mg/L (30 °C). S. ruber was approximately six times more sensitive to methomyl than O. taurinus across temperatures. Methomyl exposure did not alter CT_max in either species, although variability increased in O. taurinus at higher concentrations. These findings provide novel evidence of temperature-modulated methomyl toxicity in Amazonian frog tadpoles, highlighting the need to incorporate native species, sublethal endpoints, and climate-relevant stressors in ecotoxicological risk assessments.

Humic substances, formed through the decomposition of plant and animal matter, are prevalent world-wide. These substances primarily consist of humin, humic acid (HA), and fulvic acid (FA). There is existing evidence for antifungal properties of these humic constituents. This study aimed to isolate and determine the humic materials derived from organic materials and vermicompost produced using Perionyx excavatus, and to evaluate their antifungal activity against human fungal pathogens, specifically Candida species. Characterization of the humic and FAs was conducted using various techniques, UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and x-ray diffraction (XRD). The results revealed that HA possesses a honeycomb-like structure with fragments and flakes attached to its surface, along with a lumpy and close-grained physical appearance. SEM and XRD analyses further demonstrated the presence of specific crystalline forms in all humic and FA samples. The absorption peaks observed between 250 and 500 nm were indicative of the significant nature of HA. Additionally, the study identified the presence of hydroxyls, amines, alkyl groups, alcoholic contents, and acidic functional groups. Notably, the growth of Candida species was significantly inhibited by both humic and FAs, suggesting that these natural substances could potentially reduce the reliance on chemical antifungal drugs, which often have adverse side effects. Earthworms play a crucial role in breaking down organic matter to form humic substances, as evidenced in vermicompost, vermicast, and vermiwash. Thus, humic and FAs derived from vermiproducts demonstrate potential as alternative therapies for human fungal pathogens.

The combination of auxin-mimicking herbicides from different chemical groups offers an alternative for controlling fleabane (Conyza spp.) in soybean pre-sowing, but care is needed to avoid phytotoxicity. This study evaluated the effectiveness of auxinic herbicide mixtures in controlling Conyza spp. and their residual effects on soybean plants. A randomized block field experiment tested 13 combinations of auxinic herbicides with glyphosate, followed by glufosinate 14 days after application (DAA). At 42 DAA, all the treatments provided satisfactory control, with triclopyr + halauxifen + diclosulan achieving 100% effectiveness, while the 2,4-D combinations were controlled at 80-90%. Aminopyralid caused the highest phytotoxicity (50-75%), while dicamba caused less than 25% phytotoxicity. Aminopyralid also significantly reduced yield and thousand-grain weight to nearly zero, whereas the other treatments maintained yields of approximately 2,500 kg ha^-1. These results demonstrate the efficacy of auxinic herbicide combinations for managing Conyza spp., provided that the phytotoxic risks to soybean are carefully managed.

This study explores the photocatalytic decomposition of antibiotic residues, including tetracycline (TCR) and amoxicillin (AMR), from wastewater using Bi₂O₃@C₃N₄ photocatalyst. The characterization findings revealed that Bi₂O₃@C₃N₄ exhibited significantly improved light absorption properties and enhanced charge separation efficiency. According to the experimental results, Bi₂O₃@C₃N₄ exhibited high degradation efficiencies of 77.6% for TCR and 83.2% for AMR in wastewater samples. It also displayed excellent reusability, with the removal efficiencies of TCR and AMR remaining at 71.3 and 78.8%, respectively, after five cycles. Additionally, the photodegradation of TCR and AMR using Bi₂O₃@C₃N₄ is suggested to follow the Z-scheme pathway. The results of this study could be utilized for removing antibiotic pollutants from wastewater, thereby reducing their impact on human health and the environment.

Non-target microorganisms in soil are very important for the restoration of soil fertility and the safety of soil microecosystem. Currently, the effects of the bactericides, pyraclostrobin and metalaxyl-M, for the control of tobacco black shank disease and bactericides, trichloroisocyanuric acid and thiodiazole copper, for the control of tobacco bacterial wilt disease on soil microecology are still unclear. In this study, high-throughput sequencing technology was used to analyze the diversity, community structure and function of soil bacteria in tobacco fields after root-irrigation with pyraclostrobin, metalaxyl-M, trichloroisocyanuric acid and thiodiazole copper. The results showed that treatment with trichloroisocyanuric acid and thiodiazole copper significantly increased soil organic matter content, ammonium nitrogen content, and electrical conductivity, while reducing bacterial abundance and diversity. Pyraclostrobin and metalaxyl-M enhanced Actinobacteria abundance by 15.2% (p < 0.05) but reduced Proteobacteria and Acidobacteria by 8.7% and 6.3%, respectively, with no significant changes in overall community diversity (Shannon index, p > 0.1). Functional prediction analysis showed that trichloroisocyanuric acid and thiodiazole copper could increase the relative abundance of metabolic functional genes in soil bacterial communities. This study has laid a solid foundation for the environmental behavior and scientific use of pyraclostrobin, metalaxyl-M, trichloroisocyanuric acid and thiodiazole copper in soil.

The objective of this study was to evaluate the selectivity of four post-emergence herbicides in the cultivation of industrial hemp. Hemp was grown in 3.5 L pots with inert substrate in the absence of weeds throughout the crop cycle. The experimental design adopted was a randomized, complete block design with five treatments and four replications. The herbicides atrazine (2.500 g a.i./ha), clethodim (96 g a.i./ha), fomesafen (250 g a.i./ha), and nicosulfuron (54 g a.i./ha) were applied when the plants were approximately 35 days after cutting. Visual assessments of herbicide-induced injury symptoms were conducted, along with measurements of the number of leaves, plant height, stem diameter, and total aerial part dry mass. When nicosulfuron was applied after emergence, it caused 60.0% damage 21 days after application (DAA), which changed the number of leaves, height, stem diameter, and total aerial part dry mass of hemp plants in a big way. Fomesafen caused 42.5% injury at 5 DAA, and atrazine caused 42.5% injury at 21 DAA, which may compromise the final yield. Therefore, it is recommended to use only clethodim, a selective herbicide for broadleaf plants such as hemp, as it did not cause significant injuries during the evaluation period.

The widespread use of antibiotics has led to significant water pollution. Photocatalysis can effectively degrade antibiotics, but the performance is greatly limited by the photogenerated carrier recombination in the photocatalytic material g-C₃N₅. Constructing heterojunctions can enhance interfacial charge transfer, leading to more stable and efficient photocatalysis. This study synthesized a Fe₂O₃/g-C₃N₅ heterojunction using the solvothermal method. The Z-scheme charge transfer mechanism facilitated efficient separation of photogenerated carriers, preserving photoelectrons and holes with high redox activity. This process generated a substantial amount of highly reactive free radicals such as ·O₂^- and ·OH, enabling the efficient degradation of tetracycline (TC). Under the optimal conditions of initial concentration of TC was 200 mg/L, the quality ratio of Fe₂O₃ and g-C₃N₅ was 1:2, the catalyst dosage was 50 mg and pH = 7.0, the TC degradation rate reached 92.46% within 60 min of visible light irradiation. The photocatalytic activity's enhancement was attributed to broad spectral absorption and effective photogenerated carrier separation. Furthermore, the photocatalytic performance can be affected by the presence of inorganic salt ions such as HCO₃^- and CO₃^2-.

There is growing evidence that environmental benzene exposure is a risk factor for developing some hematological disorders, leukemia included. The aim of this study was to assess the variation in mRNA expression of a regulatory set of hematopoietic genes in children exposed to benzene and hematological parameters. In this study, 67 healthy children between the ages of 3 and 12 voluntarily participated. Trans,trans-muconic acid was analyzed in urine samples using high-performance liquid chromatography, and gene expression of AhR, BCL2, CD38, PTEN, and RUNX1 was assessed in blood samples by RT-qPCR. We observed elevated benzene exposure levels (GM = 326.3 ± 42.3 µg/g creatinine), with 20% of children exceeding the occupational threshold of 500 µg/g creatinine. Additionally, benzene exposure was significantly associated with RUNX1 mRNA expression (r = 0.27, p < 0.05). Our finding show that benzene could contribute to hematopoietic effects developed in highly exposed children. These results highlight the necessity of implementing environmental policies aim at reducing benzene exposure in children.

The aim of this study was to analyze persistent organic pollutants (POPs) in water, sediment and fish samples from Fierza Lake, Albania. Water, sediment and fish samples were collected in December 2023 and May 2024. The samples were analyzed for polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) by using GC-MS/MS. Total PCB concentrations in water, sediment and fish ranged from < MDL to 4.372 ± 0.957 μg/L, < MDL to 4.217 ± 0.968 μg/kg and < MDL to 5.849 ± 0.953 μg/kg, respectively. PAHs in water, sediment and fish samples ranged from < MDL to 0.195 ± 0.061 μg/L, < MDL to 0.203 ± 0.067 μg/kg and < MDL to 0.227 ± 0.072 μg/kg, respectively. OCP concentrations in water, sediment and fish ranged from < MDL to 3.626 ± 1.058 μg/L, < MDL to 3.032 ± 0.724 μg/kg and < MDL to 3.558 ± 1.108 μg/kg, respectively. The highest detected concentrations of PCBs and specific OCPs surpassed the Environmental quality standards established by the European Union's Water-Framework Directive for surface water and aquatic biota. These exceedances indicate potential ecological risks and pose concerns regarding bioaccumulation and human health through the consumption of contaminated fish.

In this study, the spraying performance of two unmanned aerial vehicles (UAVs), the DJI T10 and the DJI T30, was evaluated for herbicide application in wheat cultivation under different application volumes. The UAVs were tested at application volumes of 10, 20 and 30 L ha^-1, and their performance was evaluated based on spray coverage rate, deposition, and distribution uniformity. Field experiments were conducted in Adana, Türkiye, using Water Sensitive Paper (WSP) to collect data from 15 sampling points per plot. The T30 UAV achieved the highest coverage rate (39.69%) and deposition value (0.194 µL cm^-2) at 30 L ha^-1, demonstrating a more uniform spray distribution across all sampling points, including the edge areas. In contrast, the T10 UAV showed a maximum of 32.22% coverage rate and a deposition of 0.175 µL cm^-2, with a higher concentration at the central points and a lower uniformity at the edges. These findings suggested that the T30 UAV provided superior performance in higher application volumes, while the T10 would be more suitable for targeted or small-scale applications.