Bulletin of Environmental Contamination and Toxicology最新文献

Weeds growing in crops contribute to the maintenance of soil biodiversity; for example, they are a source of organic matter and nutrients for soil invertebrates. However, little is known about the impact of glyphosate-contaminated weeds on the behavior and survival of earthworms. The objective of this study was to evaluate the behavior and survival of the earthworm Eisenia andrei upon exposure to glyphosate-contaminated weed compost. The study employed standardized avoidance and acute tests to assess the repellency and mortality of E. andrei earthworms at four doses of the commercial herbicide (Faena Fuerte® 360): 0, 259, 398 and 437 mg/kg/ha. The avoidance essay results indicated that earthworms with similar biomass did not avoid glyphosate-contaminated weed composts, with avoidance rates < 80%. Furthermore, the acute test showed that commercial dose of glyphosate was not associated with growth and mortality. Consequently, it was concluded that weed composts with glyphosate not exert a sublethal and lethal toxic effect on E. andrei. It is recommended that future studies focus on the microbiota associated with native endogenous earthworms in the decomposition of the weed and the degradation of the herbicide.

Cadmium (Cd) is a heavy metal, and chlorpyrifos (CPF) is a widely used organophosphorus insecticide, which are widespread environmental pollutants. These two chemicals can induce the production of reactive oxygen species (ROS) in mammals and cause oxidative damage. However, the mechanism of their combined toxicity in invertebrates and especially insects has not been well documented. In this study, we investigated the combined toxicity of Cd and CPF by using Drosophila S2 cell as a test model. We found that cell viability and antioxidant enzyme activities were reduced and the lipids and proteins peroxidation as well as ROS were induced after the treatment. Cd and CPF displayed an antagonistic interaction in the induction of oxidative damage and the reduction of cell viability. The results indicated that Cd and CPF interfere with the toxicity of each other in the cells, which implies that Cd could influence the effect of CPF used for pest insects control.

Hexavalent chromium (Cr⁶⁺) is a known carcinogen that has been listed as a priority pollutant by the Environmental Protection Agency (EPA). The toxic effects of Cr⁶⁺ in some organisms, especially aquatic animals have received considerable attention over the years but not much is known about the adverse effects of Cr⁶⁺ in terrestrial insects despite their potential exposure to Cr⁶⁺ through ingestion of contaminated food and water. Therefore, this study aimed at investigating the effects of Cr⁶⁺ on the survival, growth and development of the blowfly, Chrysomya chloropyga. The eggs of C. chloropyga that were collected from laboratory stock were exposed to dietary Cr⁶⁺ at different concentrations; 0, 4, 8, 12, 16, and 20 mg/mL and the eggs were monitored throughout the developmental stages till adult emergence, during which growth (length, width, and weight at larval and pupal stages) and developmental parameters (duration of development at different stages, egg hatchability, pupation, and adult emergence) were measured. Exposure to Cr⁶⁺ prolonged the developmental period in the blowflies with total developmental period reaching 231.00 ± 1.45 h in the insects that were treated with 20 mg/mL Cr⁶⁺ compared with 217.91 ± 1.16 h in the control. The percentage hatchability, pupation rate and number of emerged adults reduced significantly in groups exposed to Cr⁶⁺ (especially at 20 mg/mL) compared to the control. The mean length, width and weight decreased significantly in insects exposed to dietary Cr⁶⁺ at all the immature stages. The results of this study showed that dietary Cr⁶⁺ exposure have adverse effects on the growth and development of C. chloropyga.

Biochar is extensively used in environmental remediation, but the effects of aging on the immobilization of cadmium (Cd) in contaminated soils treated with biochars containing various endogenous Cd is unclear. This study investigated the effects of simulated acid rain (SAR) aging on the bioavailability of Cd in soil amended with two rice straw biochars (RSBs, marked as RS1 and RS2) and two sludge biochars (SSBs, marked as SS1 and SS2) under flooding condition. Results showed that SSBs had higher specific surface area, ash, silicate contents, and more functional groups than those of RSBs. The total Cd in the biochars followed the order of RS1 > RS2 > SS1 > SS2. SSBs applications significantly decreased soil CaCl₂-extractable and acid-soluble Cd by 51.3%-78.6% and 4.51%-5.44% after a 30-day incubation with 70% water holding capacity than the control. SAR aging significantly decreased the soluble, CaCl₂-extractable, and acid-soluble Cd in all treatments compared with those before aging. This may be due to the decreased effects from the formation of insoluble Cd sulfide and the adsorption of Cd by Fe-Mn (oxidro)oxides under continuous flooding condition was outweighed the increase in soluble Cd caused by SAR accumulation. Moreover, the soluble, CaCl₂-extractable, and acid-soluble Cd in RSBs treated soils were significantly higher than those of SSBs after SAR aging. The study indicated that the RSBs with high endogenous Cd posed greater environmental risks, thus the long-term effects of biochar application in soil need further study.

The heavy metal contamination of Bohai Sea, the largest inland sea and a major fishing ground in China, has raised wide public concern in recent years and may pose serious threats to human health and ecological system. However, the sedimentary records of heavy metals in Bohai Sea were still relatively rare. In this study, we sampled a sediment core B13 in the central Bohai Sea, investigated the levels and vertical distributions of heavy metals, assessed the pollution history and ecological risks. Our results indicated that the vertical distributions of heavy metals showed a steady increasing trend towards the surface and the sediment profile B13 showed slight pollution with As, Sb and Pb. Moreover, the As, Sb and Ni may also have non-negligible ecological risks. Based on comprehensive analysis of the above results, the vertical distributions of these proxies may reflect the potential fingerprints of anthropogenic impact intensities over the past few decades. Our results provide valuable information for understanding the heavy metal pollution records and its potential influence of human activities in Bohai Sea.

A Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC) method was developed and validated to simultaneously quantify six contaminants of emerging concern (CECs) in the context of microalgae bioremediation. RP-HPLC was chosen for its ability to separate substances of differing polarities, its use of cost-effective and low-toxicity mobile phases, and the capacity to selectively adjust pH for enhanced sample resolution. To validate this method, standard guidelines were followed to evaluate system suitability, linearity, accuracy, precision, recovery, limits of detection and quantification, selectivity and specificity. Limits of detection and limits of quantification were, respectively, 0.017 and 0.051 µg mL^-1 for paracetamol (PAR), 0.024 and 0.072 µg mL^-1 for methylparaben (MP), 0.008 and 0.027 µg mL^-1 for imidacloprid (IMID), 0.014 and 0.041 µg mL^-1 for bisphenol A (BPA), 0.023 and 0.069 µg mL^-1 for triclosan (TCS) and 0.016 and 0.048 µg mL^-1 for ibuprofen (IBU). Precision and accuracy values assessed inter-day and intra-day were all within the acceptance limits of relative standard deviation (%RSD) and %bias of less than 15%. Percentage recovery was determined to be within the acceptable range of 80-120%, except for TCS due to low solubility. Applicability was demonstrated by assessing the effect of contaminant exposure to microalgae cells, and contaminant removal. The developed method is linear, precise and accurate and has been successfully applied to the quantification of the six contaminants during microalgae bioremediation.

Amide herbicides (AHs), commonly applied in agriculture, are now known to inhibit the activity of alkaline phosphatase (AKP), subsequently disturbing the soil microbial community and spurring significant shifts in soil nutrient dynamics. The complex mechanisms governing the interaction between AHs and AKP, along with the impact of halogen substituents in AHs on AKP function and this study sets out to investigate these interactions. By integrating computational docking techniques with Spearman correlation analysis and focusing on seven typical AHs, we probed the mechanisms of the AHs-AKP complex and aimed to clarify the structure-activity relationship between these herbicides and AKP. Our findings disclose that within the AKP-AHs complex, the proportion of neutral amino acids peaked at 48.41%. The chief interaction patterns between AKP and AHs hinged on hydrogen bonding and hydrophobic interactions. Among the AHs, butachlor exhibited the largest binding area (BA ≈ 452.61 Ų), implying stronger binding than its counterparts. In contrast, propanil manifested the maximum absolute value of binding energy (|BE|) at 2.94 kJ/mol, indicating that it may possess stronger binding characteristics despite the larger BA of butachlor. This discrepancy may be attributed to the chlorine atom content of propanil relative to the other AHs, which enhances its interaction with AKP through increased hydrophobicity and specific interactions. Moreover, our analysis reveals a negative correlation between the molecular weight (MW) of the AHs and their corresponding |BE| values, signifying that as MW rises, the binding energy of the AHs-AKP interaction declines. This suggests a potential inverse relationship. In sum, these findings provide critical technological insights and foundational theory for understanding the harmful impacts of AHs via the halogen effect (Cl) on soil enzyme inhibition, with implications for health risk management and regulation. These insights are crucial for understanding the environmental impact of AHs and informing risk management strategies.

Previous health risk assessments of particulate polycyclic aromatic hydrocarbons (PAHs) have ignored the size distributions and respiratory tract deposition rates, resulting in significant bias. To calculate the health risks of depositing PAHs, this study investigates the size-resolved dynamics of particulate PAHs and associated deposition fluxes in Baoding, a representative inland city in China's Beijing-Tianjin-Hebei air pollution corridor. Size-segregated aerosol sampling (n = 20 batches) across four seasons revealed: coarse particles (> 2.1 μm) dominated PM mass in spring (67%), summer (60%), and autumn (60%), while winter exhibited fine particle (< 2.1 μm) dominance (62% of TSP). All PAHs demonstrated bimodal size distributions with accumulation (0.43-0.65 μm) and coarse modes (4.7-5.8 μm). Low-molecular-weight PAHs show more significant volatility-driven migration to coarse particles than high-molecular-weight PAHs. The deposition fluxes of size-segregated PM and PAHs were calculated by multi-path particle dosimetry model. Compared with adults, children have a 32-40% higher flux of coarse PM deposition. In addition, the deposition fluxes of coarse PM is higher than fine PM. These findings challenge conventional fine PM-centric risk frameworks, highlighting the necessity to reconsider coarse PM toxicity for child-specific exposure in northern China's inland cities.

There have been reports confirming the presence of microplastic pollution in rice fields, which have potential negative effects on rice cultivation. In this article, the growth characteristics and oxidative stress levels of rice seeds were analyzed in the presence of polystyrene microplastics with different particle sizes (50 μm, 50 nm) and concentrations (0-1500 mg/L), as well as their co-exposure to 2,4-epibrassinolide. The micro-particles had no significant effect on the growth of rice seeds, however, the nano-plastic had an inhibitory effect on the growth of rice seed and the effect was the strongest at high concentration. The addition of brassinolide alleviated the inhibitory effect of the nano-plastics on rice seed. The oxidative stress level results indicated that the addition of brassinolide weakened the oxidation induction effects of microplastics, improved the antioxidant capacity of rice seeds under microplastics stress.

This study investigated the distribution, sources, and ecological toxicity of polycyclic aromatic hydrocarbons (PAHs) in surface sediments along the Mekong River, from its entry into Vietnam to its outflow into the East Sea. The results showed that total PAH concentrations ranged from 53.66 to 1205.35 ng/g dry weight, with an average of 281.08 ± 391.13 ng/g dry weight. Among the 16 PAH compounds analysed, Pyrene (Pyr) and Fluoranthene (Flu) were detected in all sediment samples. Naphthalene (Nap) had the highest concentration among the detected PAHs. Diagnostic ratio and principal component analyses indicated that PAHs originated from mixed sources, including traffic emissions, coal and biomass combustion, petroleum leakage, and wastewater discharge. Based on the risk quotient (RQ), PAHs posed low to moderate ecological risks. Both adults and children in the study area may be exposed to cancer risks due to the presence of carcinogenic PAHs in sediment samples.