Bulletin of Environmental Contamination and Toxicology最新文献

The widespread presence of pharmaceutical compounds in the environment raises increasing concerns about their ecological impacts, particularly on non-target organisms. This study investigates the biochemical and physiological effects of midazolam, a clinically used benzodiazepine, on Galleria mellonella larvae as a model organism. In this study, the effects of dietary midazolam on metabolic enzyme activity, biochemical parameters and antioxidant levels in G.mellonella were determined. Results indicated significant alterations in enzyme levels, including increased levels of aspartate transferase, alanine transferase, and lactate dehydrogenase, suggesting cellular damage. In addition, the levels of energy metabolism regulators such as creatine kinase, alkaline phosphatase and amylase changed due to the oxidative effect of midazolam. Additionally, antioxidant levels, including albumin, uric acid and bilirubin were altered, indicating a response to oxidative stress. Molecular docking studies revealed a strong interaction between midazolam with juvenile hormone and 20-hydroxyecdysone hormone binding proteins, suggesting potential disruption of the endocrine system. These findings contribute to understanding the potential ecological risks posed by environmental contamination with neuroactive pharmaceuticals like midazolam.

Nano-selenium (nano-Se) has garnered widespread attention for its potential to alleviate plant abiotic stress. However, despite its promising applications, the specific effects of nano-Se on barley seedling growth under cadmium (Cd) stress largely unexplored. In this study, nano-Se was synthesized, and the optimized product was characterized. Additionally, the regulatory effects of different nano-Se concentrations on barley seedlings under Cd stress were investigated. The results revealed that a high concentration of nano-Se inhibited barley growth, whereas low doses promoted plant growth under Cd stress, with the highest growth parameters recorded at 2 µmol L^- 1 (µM) nano-Se. Furthermore, low doses of nano-Se increased chlorophyll levels and improved photosynthetic efficiency. Additionally, nano-Se application at low concentrations protected barley plants from oxidative damage by reducing the levels of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), as well as decreasing the activities of root peroxidase (POD) and superoxide dismutase (SOD) induced by Cd stress, as well as reducing the total flavonoid content.

Microplastic pollution is a significant concern, prompting an assessment of commercially important seafood species in Mandapam, Pamban, and Rameswaram along the Gulf of Mannar coast, Tamil Nadu. The analysis focused on shore sand, littoral sediment, seawater, and shrimps and crabs to determine microplastic presence, considering various land use patterns known to contribute significantly to pollution. As anticipated, microplastics were found to be prevalent in all samples, including sand, sediment, seawater and gut and gills of Crustaceans. Coloured polyethene fragments and polyvinyl chloride were the most prevalent types of microplastics identified. In seawater samples, coloured microfibers, PVC, and PEEK were notably abundant. Among various land uses, the fish landing centres exhibited the highest levels of plastic pollution, while residential areas also showed substantial contamination with a diverse array of microplastics and mesoplastics. The presence of microplastics in crustaceans from the seafood market certainly poses a significant threat to seafood quality.

This study investigated the impact of pH on the combined toxicity of polystyrene microplastics (MPs) and ciprofloxacin (CIP) on ryegrass growth and CIP uptake. Two different sizes of PS-COOH (200 and 500 nm) were utilized. The findings indicated that neutral and alkaline pH conditions (pH 7.0 and 8.8) significantly reduced CIP accumulation in ryegrass roots, regardless of MP presence. Conversely, CIP content in shoots (including leaves) increased with rising pH, showing 24.7-fold and 29.5-fold enhancements under CIP + 200 nm MPs and CIP + 500 nm MPs treatments at pH 8.8 compared to pH 5.3. Additionally, pH significantly influenced growth inhibition, with more pronounced effects at pH 7.0 and 8.8 than at pH 5.3. Under neutral and alkaline conditions, shoot lengths in 500 nm MPs + CIP and 200 nm MPs + CIP treatments were reduced to 50.3%, 69.7% and 86.8%, 81.3% of those at pH 5.3, respectively. These findings highlight the critical role of pH in modulating CIP uptake and toxicity in ryegrass, particularly in MP co-contaminated environments. Moreover, the relatively high CIP removal efficiency suggests the potential of ryegrass for CIP remediation in MP-polluted systems.

Cadmium (Cd) pollution in rice agroecosystems has become a pressing worldwide environmental challenge. Straw return leads to Cd re-entering the soil, yet the impact of straw removal (SR) on Cd mobility and bioavailability within this system remains unclear. We implemented a four-season field study to evaluate how different SR intensities (NSR: no rice straw was removed; HSR: half of the rice straw was removed; TSR: all the rice straw was removed) influence Cd availability in this system. Our findings indicated that after three and four consecutive seasons of SR, the DTPA-extractable Cd levels showed notable reductions of 12.2% and 13.7%, respectively. SR also decreased grain Cd concentration (Cd_G) in subsequent seasons, demonstrating a dose-dependent response. The Cd_G after one, two, three, and four seasons of TSR treatment fell by 9.0%, 25.2%, 16.8%, and 41.7%, respectively, compared to that following NSR treatment. Notably, late-season SR proved more effective in Cd_G reduction than early-season SR. Statistical analysis confirmed a strong positive association between Cd_G and DTPA-extractable Cd. The primary mechanism underlying Cd_G reduction appears to be the decreased Cd bioavailability in soil resulting from SR practices. These findings establish multi-season total straw removal as a sustainable phyto-management strategy for Cd-polluted rice cultivation systems.

The use of mercury (Hg) in artisanal gold mining in San Martin de Loba (SML), Bolivar, Colombia, poses significant environmental and health risks. This study aimed to evaluate total mercury (T-Hg) concentrations in chicken feathers (Gallus gallus) and soils from SML, and compare them with those obtained in a reference site without mining activity (Arjona). A total of 40 chickens and 30 soil samples were taken in SML, along with 31 chickens and 21 soil samples in Arjona. Using the Lumex RA-915 + analyzer, mean T-Hg levels in breast feathers, wing feather rachises, and barbs were 2.37 ± 0.42, 0.72 ± 0.32, 2.97 ± 1.26 µg/g in SML, and 0.41 ± 0.05, 0.23 ± 0.04, 0.76 ± 0.07 µg/g in Arjona, respectively. The average total mercury (T-Hg) concentration in soils from SML was 45.5 ± 12.4 µg/g, markedly exceeding the levels found in Arjona (0.04 ± 0.001 µg/g). The findings indicate severe contamination in SML soils and bioaccumulation in local birds eaten by humans, representing health risks to consumers.

The potential genotoxicity of the fungicide tebuconazole (TBZ) was evaluated in the freshwater fish Jenynsia lineata when exposed to 0.005, 0.05, 0.5 and 5 µg/L for 48 h. The study aimed to compare a TBZ commercial formulation (c.f.) with the TBZ active ingredient (a.i.) using the micronucleus (MN) and Comet assays. The study also investigated differences in tissue sensitivity between two cell populations: erythrocytes and epithelial gill cells. The MN frequency increased in blood from fish exposed to the c.f. or the a.i. at 5 µg/L TBZ compared to the negative control. The Comet assay revealed increased DNA damage at 0.05, 0.5 and 5 µg/L of a.i., and at 0.5 and 5 µg/L of c.f. The sensitivity of the epithelial gill cells was comparable to that of erythrocytes, enabling these cell types to be used indistinctly. We recommend including these DNA damage biomarkers in the batteries used to study the effects of current use pesticides.

QuEChERS method of extraction followed by detection with Liquid Chromatograph Mass spectrometry was carried out to determine persistence of tetraniliprole and its metabolite in pigeon pea. The mean recovery of tetraniliprole and its metabolite BCS-CQ 63359 in immature and mature pods, seeds and grains of pigeon pea and soil were in the range of 76.38-105.68. The residues of tetraniliprole in immature pod with seeds were observed to be 0.03 and 0.05 mg kg^-1 at two hours after application at single (X) and 1.25X dose, respectively. The residues in mature pods and mature seeds (dry) collected during harvesting of pigeon pea did not reveal any residues means reached below the LOQ (0.01 mg kg^-1). Metabolite BCS-CQ 63359 was found below LOQ even in samples of collected at two hours after spray. There were no residues detected in soil samples taken at harvest time. Tetraniliprole's half-lives at X and 1.25X doses were determined to be 4.39 and 5.81 days, respectively.

We analyzed mercury concentrations in two epipelagic fish species Diodon eydouxii (Pelagic Porcupinefish) and Hirundichthys affinis (Fourwing Flyingfish) and one mesopelagic species Howella atlantica (Atlantic Pelagic Basslet) from the Western Equatorial Atlantic Ocean (WEAO), examining their relationship with total length. Mercury concentrations varied significantly, with the highest levels in H. affinis. Two species showed a moderate positive correlation between Hg levels and body size. This study provides the first data on Hg bioaccumulation in these species from the WEAO and highlights the need for larger sample sizes and broader age ranges to better understand mercury transfer in pelagic food webs.

Metal(loid) contamination levels and the factors governing metal(loid) accumulation patterns in terraced agricultural systems were studied using 1250 surface (0-20 cm depth) soil samples. The average concentrations of Cr, Ni, Cu, As, Cd, Pb, and Zn were 132, 62.3, 140, 42.2, 33.8, 535, and 2384 mg kg^-1, respectively. Correlation analysis (CA) and positive matrix factorization (PMF) modeling were conducted to identify the sources of the metal(loid)s and the forest regression algorithm was used to elucidate the factors influencing their spatial differentiation. Cr and Ni originated mainly from natural soil-forming processes and As, Cd, Pb, and Zn originated from irrigation water. Cu, As, Cd, Pb, and Zn were controlled by source-related factors, and the distance to a residential area (Dis-RE) was the most significant covariate for these five elements. The results provide insights into the identification of the sources and clarification of the diffusion of metal(loid)s in similar mining regions.