Bulletin of Environmental Contamination and Toxicology最新文献

To study the effect of different salinities (0, 10, 30 and 60 dS/m) and wheat straw levels (0 and 2% by weight with C/N = 89.5) on carbon mineralization during 180 days (1, 2, 3, 5, 8, 11, 15, 19, 24, 29, 36, 46, 60, 75, 90, 120, and 180), this study was conducted at the Soil and Water Research Institute, Karaj, Iran in 2022. For this purpose, three soils with low salinity (0.84-1.1 dS/m) and low organic carbon (0.22-0.98%) with different textural classes (Loamy, Clay Loam, and Silty Loam) were selected from Iranian agricultural soils. The results showed that the amount of cumulative mineralized carbon in loamy soil ranged from 93 to 2379 mg/kg, in clay loam soil ranged from 172 to 2277 mg/kg, and in the silty loam ranged from 122 to 3158 mg/kg. Furthermore, in the studied soils, the highest amount of cumulative mineralized carbon was measured at natural soil salinity levels (i.e., low salinity 0.84-1.1 dS/m) and the lowest amount of cumulative mineralized carbon was measured in high salinity treatments. In all three soils, the amount of mineralized carbon increased rapidly in the first week and then gradually decreased, which is due to the availability of easily degradable parts of organic matter against a wide range of microorganisms in the early stages of decomposition. In general, it is concluded that the presence of wheat straw in the soil may decrease the negative effects of high salt concentrations on carbon mineralization and reduce losses.

In recent years, Zinc Sulphur Nanoparticles (ZnS-NPs) have a wide range of applications such as in optical sensor, solid state solar window layers, photoconductors, phosphors and catalysts. There are no clear data on the waste-enriching effects of this nanoparticle, whose annual consumption is over million tons, and concerns remain unanswered. This research was also designed to investigate lethal and sublethal toxicity, as well as survivability and bioaccumulation on Gammarus pulex for the effects of possible waste products of ZnS-NPs. After acute 96-hours experiments, while the lethal concentration (LC50) value was estimated at 3.39 (2.79-4.17) ppm, it was found that both the toxicity and the accumulation levels of ZnS-NPs in tissues increased with increasing exposure durations and doses. Statistically significant differences were observed in ventilation rates of the organisms as exposure durations increased at higher doses such as 2, 5, and 10 ppm. According to our results, the lowest ventilation rate was determined at the highest dose of ZnS-NPs. Moreover, ZnS-NPs was proved to be highly toxic after 3.5 ppm, while ZnS-NPs very slowly accumulate in Gammarus pulex tissues (BCF equal to 5.8.10^- 4 (4.28.10^- 4; 7.2.10^- 4) at the highest exposure dose).

Cadmium (Cd) pollution of soil is a severe environmental problem. Bioremediation of Cd-contaminated soil is an environmentally friendly and low-cost remediation method. In this work, three Cd-tolerant fungi strains, named L1, L2, and L3, were screened and domesticated. The adsorption characterization and the remediation effect of the three strains were investigated. The results show that the adsorption efficiency (AE) of Cd by the three strains reached 83.6%,73.1% and 57.1%, respectively. Scanning electron microscopy (SEM) revealed that the surface of Cd-tolerant fungus (L1) is rough, with many indents and excellent Cd adsorption sites. The prepared microbial agents reduced the exchangeable Cd content and increased other Cd contents in highly Cd-contaminated soil. In addition, the number of microorganisms and the activities of catalase and urease in the soil were also improved. The screened fungi have the remediation abilities for Cd-contaminated soil. This work aims to investigate the remediation mechanism and effect of Cd-tolerant microorganism on Cd-contaminated soil, and provide a theoretical basis for practical application.

To enhance phenanthrene degradation in soil, the effects of four surfactants on the thermal activation of sodium persulfate (SPS) were investigated. Sodium dodecyl diphenyl ether disulfonate (C₁₂-MADS) was found to stabilize SPS by reducing the generation of sulfate radicals from its thermal decomposition. Optimal conditions for the surfactant-assisted persulfate system were determined to be 5 g/L of C₁₂-MADS at a temperature of 60°C, achieving an 89.80% removal efficiency of phenanthrene in soil. The presence of OH^- increased the system pH and decreased the removal efficiency. These results demonstrate that C₁₂-MADS significantly enhanced the oxidation of phenanthrene and improves SPS utilization efficiency, contributing to the development of an effective surfactant-assisted persulfate system for soil decontamination.

Potentially toxic metal contamination in marine environments poses significant risks to both ecosystems and human health. Mussels, as filter feeders, are particularly susceptible to accumulating these contaminants, making their safety a critical concern. This study aims to investigate the correlation between potentially toxic metal concentrations in attachment ropes and mussel soft tissues in an aquaculture setting. We analyzed the levels of Hg, Cu, Zn, As, Cd, Pb, and Cr in both substrates and assessed the health risks using the Target Hazard Quotient (THQ) method. Results show that while most potentially toxic metals (Hg, Cu, Zn, Pb, Cr) in mussels present low health risks with THQ values below 1, As and Cd pose significant risks, with As showing a THQ value significantly above 1. No significant correlations were found between the potentially toxic metal concentrations in ropes and mussel tissues, indicating other environmental factors influence metal bioaccumulation in mussels. These findings underscore the necessity for comprehensive monitoring and targeted mitigation strategies to reduce potentially toxic metal contamination in aquaculture environments, ensuring the safety and sustainability of mussel production.

Three beaches on the Eastern Black Sea coast of Türkiye, with different usage purposes and urbanization, were evaluated regarding marine litter densities and categories in four seasons. 3573 marine litter items were collected, classified, and recorded. In an area of 3,000 m², the highest amount of litter was counted in summer with a total of 1473 pieces of litter (Average: 0.491 ± 0.131 items/m²), and the lowest was counted in the spring months with 577 pieces of litter (Average: 0.192 ± 0.026 items/m²). Plastics (79 ± 0.9%) were the most predominant, and litter items mainly consisted of metal (7.2 ± 0.5%) and paper/cardboard (5.6 ± 0.6%.). Beach litter was also associated with fishing activities and tourism. It was observed that litter relatively increased during the fishing season in the region where fishing activities were intense. SIMPER analysis revealed that Çamburnu, located near a fishing port, exhibited a significantly different litter composition, with fishing gear being the most dominant category.

This study focuses on the determination of dioxins and related compounds (DRCs) in sediment and soil samples gathered from craft villages and industrial zones in Bac Ninh province, northern Vietnam. The PCDD/Fs and DL-PCBs levels in sediment samples ranged from 8.34 to 1302 pg/g and 34.5 to 3186 pg/g, respectively, and total equivalent toxicity (TEQ) of DRCs ranged from 0.596 to 88.1 pgTEQ/g. The total mass concentration of DRCs in the soil samples varied from 14.2 to 4857 pg/g, with corresponding total TEQ values ranging from 0.387 to 2.61 pgTEQ/g. Risk assessment based on sediment quality guideline indicators shows that DRCs at paper recycling village had moderate adverse biological effect. Some soil samples collected in industrial clusters have total carcinogenic risk (CR) values close to the threshold (1.0 × 10^-6). Based on the results, it is necessary to continue monitoring and evaluating DRC compounds in craft village and industrial cluster environments and have remediation solutions to reduce these contaminated compounds.

Irgarol 1051 and Diuron are used as boosters in copper-based anti-fouling paints, as well as in agriculture and home gardening. We monitored the coral reefs and adjacent waters of northern Okinawa Island three times, i.e., in August 2015, June 2016 and December 2016. The mean concentrations were 1.44 ng/L for Irgarol and 1.07 ng/L for Diuron. Although the range of these concentrations was lower than those previously recorded in southern Japan, Irgarol and Diuron were significantly higher in December 2016 than in June 2016. Several estimations of Predicted No Effect Concentrations (PNECs) have recently been published. In December 2016, compared to the lowest PNEC concentration of each substances, the concentrations of Irgarol and Diuron exceeded the PNEC at nine sites and three sites, respectively. These results suggest that the effects of low concentrations of Irgarol and Diuron, close to the PNEC, on hermatypic corals need to be investigated. The regulation of anti-fouling paints in Japan is self-regulated through industry cooperation. Irgarol and Diuron have not been registered as anti-fouling paints for fishing nets by the fishing cooperatives. The significant increase of these substances suggests that the activity of vessels with paints containing Irgarol has increased in December 2016. This study highlights the need for continuous monitoring of these herbicides in coral reefs and adjacent waters.

While microplastics from lake, beach and ocean environment has become a growing global concern, tidal variations of microplastics in beach sediments are not well documented. Here, sediments were sampled over one monthly lunar tidal cycle during low tidal period in Shajing Beach along the Maowei Bay, China. The shape and abundance of microplastics were measured in sediments to determine their periodic variations by wavelet analysis method. The results showed that microplastics are generally granule, fiber and film shapes on Shajing Beach. The dominant type was fiber, followed by the granule. Meanwhile, the microplastic abundances showed a periodic change about 15 days. The granule and fiber but not film also followed such periodic variations. Tourism and human activities along the bay are the most likely causes for microplastics in Shajing Beach, while half-mouth of tidal cycle is responsible for the periodic variation of microplastic abundances and types.

Ciprofloxacin (CIP) and oxytetracycline (OTC) are commonly detected antibiotic species in breeding wastewater, and microalgae-based antibiotic treatment technology is an environmentally friendly and cost-effective method for its removal. This study evaluated the effects of CIP and OTC on Scenedesmus sp. in the breeding wastewater tailwater and the removal mechanisms of antibiotics. The results showed that Scenedesmus sp could increase antibiotic tolerance by enhancing antioxidant system activity. Compared to CIP, Scenedesmus sp showed better performance for OTC removal, the removal efficiencies were 100%, 96.87%, 95.75%, 90.18% and 83.91% at 0.1, 0.5, 1, 5, and 10 mg L^- 1 OTC, respectively. The removal routes indicated that CIP was mainly removed by biodegradation (38.88%) and photolysis (14.30%) whereas OTC was mainly removed by hydrolysis (43.47%) and biodegradation (33.45%). Product toxicity predictions showed that most of the degradation products of CIP and OTC were less toxic than their parent compounds, confirming the feasibility of microalgae biotreatment for antibiotic removal.