Bulletin of Environmental Contamination and Toxicology最新文献

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.

This study aimed to assess the environmental and health risks of heavy metal contamination from e-waste recycling in Lahore, Pakistan. Surface soil (0-15 cm) samples were collected from recycling facilities, and heavy metal concentrations were measured using atomic absorption spectrophotometry. The mean concentrations (mg/kg) of Cadmium (Cd) (5.38), Copper (Cu) (835.53), Lead (Pb) (468.90), Mercury (Hg) (1.61), and Zinc (Zn) (416.39) exceeded European Union (EU) guidelines, while Manganese (Mn) (372.29), Iron (Fe) (750.05), Arsenic (As) (6.96) and Chromium (Cr) (64.80) were within limits. Soil contamination indices indicated soil quality deterioration. The highest ecological risks (Er) were from Cd (1646.232) and Hg (322.15). Children faced higher non-carcinogenic risk (2.93) and carcinogenic risk (1.76 × 10⁻³), particularly from Pb (1.74) and Cu (1.56 × 10⁻³), respectively, while adults faced no significant risks. These findings highlight the need for sustainable e-waste management practices in Pakistan.

Urban brownfields are abandoned industrial areas. They are generated as a result of land use transition in areas of rapid economic development within the urban context and are commonly contaminated with heavy metals and/or organics. Heavy metals lead to environmental degradation and functional degradation of the soil, thereby threatening the entire ecosystem. This work investigated the occurrence, sources, and risks of five target heavy metals in the old industrial city (Plots A, B, and C) of Wuhan. The heavy metal concentrations ranged from 0.02 to 253.00 mg/kg, and the dominant heavy metals were Hg, Pb, and Cu. Traffic emission/coal combustion and industry/natural/agricultural activities were identified as the main sources by the positive matrix factorization (PMF) model. The pollution load index (PLI), the potential ecological risk index (RI), and the geo-accumulation index (I_geo) results showed that Plot A had the highest soil risk, followed by Plots B and C. The carcinogenic effects on some sites of Plot A need to be considered. This work provides a theoretical basis for the assessment of heavy metal pollution and helps local governments to redevelop brownfields.