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Результаты 2071-2080 из 8,010
Antibiotics in mariculture organisms of different growth stages: Tissue-specific bioaccumulation and influencing factors Полный текст
2021
Zhang, Xuanrui | Zhang, Jiachao | Han, Qianfan | Wang, Xiaoli | Wang, Shuguang | Yuan, Xianzheng | Zhang, Baiyu | Zhao, Shan
Maricultured organisms are chronically exposed to water containing antibiotics but the bioaccumulative behavior of antibiotics in exposed organisms at different growth stages has received little attention. Here, we investigated the concentrations and tissue-specific bioaccumulation characteristics of 19 antibiotics during three growth stages (youth stage, growth stage, and adult stage) of various organisms (Scophthalmus maximus, Penaeus vannamei, Penaeus japonicus, and Apostichopus japonicus) cultivated in typical marine aquaculture regions, and explored the factors that could affect the bioaccumulation of antibiotics. Tetracyclines (TCs) and fluoroquinolones (FQs) were the dominant antibiotics in all organisms, and the total concentrations of the target antibiotics in fish (S. maximus) were significantly higher than those in shrimp (P. vannamei and P. japonicus) and sea cucumber (A. japonicus) (p < 0.01). The bioaccumulation capacity of a class of statistically significant antibiotics in most samples was strongest during the youth stage and weakest during the adult stage. The antibiotics exhibited higher bioaccumulation capacity in lipid-rich tissues (fish liver and shrimp head) or respiratory organs (fish gill) than muscle. Our results also reveal significant metabolic transformation of enrofloxacin in fish. Different from previous studies, the logarithm bioaccumulation factor (log BAF) was positively correlated with log Dₗᵢₚw in low-biotransformation tissues (fish gill and muscle) rather than lipid-rich tissues (fish liver). Based on the calculated hazard quotients (HQ), doxycycline in fish muscle may pose a distinct risk to human health, which deserves special attention. Overall, these results provide insight into the bioaccumulation patterns of antibiotics during different growth stages and tissues of maricultured organisms.
Показать больше [+] Меньше [-]A common fungicide, Pristine®, impairs olfactory associative learning performance in honey bees (Apis mellifera) Полный текст
2021
DesJardins, Nicole S. | Fisher, Adrian | Ozturk, Cahit | Fewell, Jennifer H. | DeGrandi-Hoffman, Gloria | Harrison, Jon F. | Smith, Brian H.
Although fungicides were previously considered to be safe for important agricultural pollinators such as honey bees, recent evidence has shown that they can cause a number of behavioral and physiological sublethal effects. Here, we focus on the fungicide Pristine® (active ingredients: 25.2% boscalid, 12.8% pyraclostrobin), which is sprayed during the blooming period on a variety of crops and is known to affect honey bee mitochondria at field-relevant levels. To date, no study has tested the effects of a field-relevant concentration of a fungicide on associative learning ability in honey bees. We tested whether chronic, colony-level exposure at field-relevant and higher concentrations of Pristine® impairs performance on the proboscis extension reflex (PER) paradigm, an associative learning task. Learning performance was reduced at higher field-relevant concentrations of Pristine®. The reductions in learning performance could not be explained by effects on hunger or motivation, as sucrose responsiveness was not affected by Pristine® exposure. To determine whether Pristine®‘s negative effects on learning performance were mediated at a specific life stage, we conducted a cross-fostering experiment that exposed bees to the fungicide either only as larvae, only as adults, or during both stages. We found that exposure across the entire life was necessary to significantly reduce learning performance, although non-significant reductions occurred when bees were exposed during just one stage. Our study provides strong evidence that Pristine® has significant sublethal effects on learning performance. As associative learning is a necessary ability for foraging, our results raise concerns that Pristine® could impair foraging abilities and substantially weaken colony health.
Показать больше [+] Меньше [-]Environmental impact of amino acids on selenate-bearing hydrocalumite: Experimental and DFT studies Полный текст
2021
Wang, Mengmeng | Akamatsu, Hirofumi | Dabo, Ismaila | Sasaki, Keiko
Selenium (Se) radioactive wastes can be disposed through stabilization/solidification (S/S) based on the cementitious matrix on hydration products, where hydrocalumite (Ca₂Al-LDH) is expected to play an important role in the retention of SeO₄²⁻. Natural organic matters (NOMs) are known to be a risk to affect the transportation and mobility of undesirable chemical species in the pedosphere which receives the low level radioactive wastes (LLW). In the present work, five amino acids were selected as the simplified models of NOMs in the pedosphere to explore their effects on the stability of Ca₂Al-LDH after immobilized SeO₄²⁻ under alkaline conditions. As the loading amount of amino acids on Ca₂Al-LDH increasing, release of SeO₄²⁻ was enhanced in HGly, H₂Asp, and H₂Cys series, while no enhancement was observed in HPhe and HTrp series. Density functional theory (DFT) calculation predicted ion-exchange of amino acids and CO₃²⁻ with SeO₄²⁻ in a unit cell of LDH model. The intercalation of Asp²⁻ and CO₃²⁻ caused 003 peaks in XRD sharper and d₀₀₃ decreased from 8.15 Å to 7.70 Å which is assigned to Ca₂Al-LDH(Asp, CO₃). In H₂Cys series, the 003 peaks were kept broad and SeO₄²⁻ was still relatively maintained in LDH which was caused by the lower amounts of intercalated CO₃²⁻ in the presence of H₂Cys. Amino acids in the interlayer of Ca₂Al-LDH have several possible configurations, where the most stable one is prone to be in a horizontal direction through hydrogen bonds and Ca–O chemical bonds. This provides an insight on the stability of selenate immobilized in hydrocalumite, which can be produced in cement disposing in the pedosphere for a long term of burying. Not only carbonate but also small molecular organic matters like amino acids possibly give environmental impact on the mobility of low level anionic radionuclides in LDH.
Показать больше [+] Меньше [-]Assessment on chronic and transgenerational toxicity of methamphetamine to Caenorhabditis elegans and associated aquatic risk through toxicity indicator sensitivity distribution (TISD) analysis Полный текст
2021
Wang, Zhenglu | Dai, Shuiping | Wang, Jinze | Du, Wei | Zhu, Lin
Evidence about the adverse effects of methamphetamine (METH) on invertebrates is scarce. Hence, C. elegans, a representative invertebrate model, was exposed to METH at environmental levels to estimate chronic and transgenerational toxicity. The results of chronic exposure were integrated into an underlying toxicity framework of METH in invertebrates (e.g., benthos) at environmentally relevant concentrations. The induction of cellular oxidative damage-induced apoptosis and fluctuation of ecologically important traits (i.e., feeding and locomotion) might be attributed by the activation of the longevity regulating pathway regulated by DAF-16/FOXO, and detoxification by CYP family enzymes. The adverse effects to the organism level included impaired viability and decreased fecundity. The results from transgenerational exposure elucidated the cumulative METH-induced damage in invertebrates. Finally, a new risk assessment method named toxicity indicator sensitivity distribution (TISD) analysis was proposed by combining multiple toxicity indicator test data (ECₓ) to derive the hazardous concentration for 10% indicators (C₁₀) of one species. The risk quotient (RQ) values calculated by measured environmental concentrations and C₁₀ in southern China, southeastern Australia, and the western US crossed the alarm line (RQ = 5), suggesting a need for long-term monitoring.
Показать больше [+] Меньше [-]Effects of inhomogeneous ground-level pollutant sources under different wind directions Полный текст
2021
Wang, Huanhuan | Ngan, Keith
Effects of source inhomogeneity on pollutant dispersion from a cubic building array are investigated as a function of the external wind direction. Using building-resolving large-eddy simulation, it is found that the results depend strongly on the source location and source uniformity inside a near-field region defined by a radius of homogenisation (RAD) based on the spatial autocorrelation of the pollutant concentration. The sensitivity of the RAD to the source location changes abruptly around 30° and is greatly reduced for wind angles between 30 and 45°, in agreement with velocity statistics and the mean horizontal streamlines. The optimal source allocation, which is a proxy for emissions from time-dependent traffic, also changes around 30°. This work clarifies the relationship between inhomogeneous velocity and pollutant statistics and may be applied to the formulation of traffic control policy.
Показать больше [+] Меньше [-]Polystyrene microplastics disrupt the blood-testis barrier integrity through ROS-Mediated imbalance of mTORC1 and mTORC2 Полный текст
2021
Wei, Yuexin | Zhou, Yu | Long, Chunlan | Wu, Huan | Hong, Yifan | Fu, Yan | Wang, Junke | Wu, Yuhao | Shen, Lianju | Wei, Guanghui
It has been found that polystyrene microplastics (PS-MPs) exposure leads to decreased sperm quality and quantity, and we aim to explore the underlying mechanisms. Therefore, we gave 20 mg/kg body weight (bw) and 40 mg/kg bw 4 μm and 10 μm PS-MPs to male Balb/c mice by gavage. RNA sequencing of testes was performed. After PS-MPs exposure, blood-testis barrier (BTB) integrity was impaired. Since cytoskeleton was closely related to BTB integrity maintenance, and cytoskeleton disorganization could be induced by PS-MPs exposure in the testis, which resulted in the truncation of actin filaments and disruption of BTB integrity. Such processes were attributed to the differential expression of Arp3 and Eps8 (two of the most important actin-binding proteins). According to the transcriptome sequencing results, we examined the oxidative stress level in the testes and Sertoli cells. We found that PS-MPs exposure induced increased reactive oxygen species (ROS) level, which destroyed the balance between mTORC1 and mTORC2 (the mTORC1 activity was increased, while the mTORC2 activity was decreased). In conclusion, PS-MPs induced the imbalance of mTORC1 and mTORC2 via the ROS burst, and altered the expression profile of actin-binding proteins, resulting in F-actin disorganization and reduced expression of junctional proteins in the BTB. Eventually PS-MPs led to BTB integrity disruption and spermatogenesis dysfunction.
Показать больше [+] Меньше [-]The occurrence of opioid compounds in wastewater treatment plants and their receiving water bodies in Gauteng province, South Africa Полный текст
2021
Kamika, Ilunga | Azizi, Shohreh | Muleja, Adolph A. | Selvarajan, Ramganesh | El-Liethy, Mohamed Azab | Mamba, Bheki B. | Nkambule, Thabo T.I.
The continuous influx of opioid compounds into aquatic environments has become an increasing and persistent concern, due to their extensive use. This is especially alarming as wastewater treatment plants (WWTPs) are unable to completely remove them. Despite the reported health concerns, the occurrence of opioid compounds in the environment has not received much attention. The present study investigates the occurrence of 19 opioids in four WWTPs and their respective receiving water bodies. All wastewater samples revealed opioids at concentration ranging from ng/L to μg/L with most influents having higher concentrations than effluents. WWTPs appeared to perform poorly (p > 0.05 between influents and effluents), and were unable to remove some opioids including Methadone (−27.3%) from the Leeuwkuil WWTP, Codeine (−21.7%) and Thebaine (−3.77%) from the Sandspruit WWTP, and Hydrocodone (−1.06%) from the Meyerton WWTP, respectively. Samples collected from the Leeuwkuil WWTP were the most contaminated, with eighteen out of nineteen opioid analogues exceeding 1 μg/L. Upstream surface water contained less opioids (most < LOQ) than downstream (p < 0.05), with Hydrocodone, Oxycodone, Hydromorphone, Fentanyl, Ketamine and Dihydrocodeine not detected. The occurrence of high concentrations of opioid analogues in downstream surface water (298 ng/L −10.8 μg/L for Klip River, 4.49 ng/L −13.1 μg/L for Vaal River, 70.5 ng/L −10.0 μg/L for Soutspruit River and 8.0 ng/L – 2.43 μg/L for Sun Spruit River) was directly linked to their mass loads in the respective wastewater effluent samples.
Показать больше [+] Меньше [-]Associations of polycyclic aromatic hydrocarbons exposure and its interaction with XRCC1 genetic polymorphism with lung cancer: A case-control study Полный текст
2021
Zhou, Shuang | Zhu, Qiuqi | Liu, Huimin | Jiang, Shunli | Zhang, Xu | Peng, Cheng | Yang, Guanlin | Li, Jiaoyuan | Cheng, Liming | Zhong, Rong | Zeng, Qiang | Miao, Xiaoping | Lü, Qing
Humans are extensively exposed to polycyclic aromatic hydrocarbons (PAHs) daily via multiple pathways. Epidemiological studies have demonstrated that occupational exposure to PAHs increases the risk of lung cancer, but related studies in the general population are limited. Hence, we conducted a case-control study among the Chinese general population to investigate the associations between PAHs exposure and lung cancer risk and analyze the modifications of genetic polymorphisms in DNA repair genes. In this study, we enrolled 122 lung cancer cases and 244 healthy controls in Wuhan, China. Urinary PAHs metabolites were determined by gas chromatography-mass spectrometry, and rs25487 in X-ray repair cross-complementation 1 (XRCC1) gene was genotyped by the Agena Bioscience MassARRAY System. Then, multivariable logistic regression models were performed to estimate the potential associations. We found that urinary hydroxynaphthalene (OH-Nap), hydroxyphenanthrene (OH-Phe) and the sum of hydroxy PAHs (∑OH-PAHs) levels were significantly higher in lung cancer cases than those in controls. After adjusting for gender, age, BMI, smoking status, smoking pack-years, drinking status and family history, urinary ∑OH-Nap and ∑OH-Phe levels were positively associated with lung cancer risk, with dose-response relationships. Compared with those in the lowest tertiles, individuals in the highest tertiles of ∑OH-Nap and ∑OH-Phe had a 2.13-fold (95% CI: 1.10, 4.09) and 2.45-fold (95% CI: 1.23, 4.87) increased risk of lung cancer, respectively. Effects of gender, age, smoking status and smoking pack-years on the associations of PAHs exposure with lung cancer risk were shown in the subgroup analysis. Furthermore, associations of urinary ∑OH-Nap and ∑OH-PAHs levels with lung cancer risk were modified by XRCC1 rs25487 (Pᵢₙₜₑᵣₐcₜᵢₒₙ ≤ 0.025), and were more pronounced in wild-types of rs25487. These findings suggest that environmental exposure to naphthalene and phenanthrene is associated with increased lung cancer risk, and polymorphism of XRCC1 rs25487 might modify the naphthalene exposure-related lung cancer effect.
Показать больше [+] Меньше [-]Static modelling of the material flows of micro- and nanoplastic particles caused by the use of vehicle tyres Полный текст
2021
Prenner, Stefanie | Allesch, Astrid | Staudner, Margarethe | Rexeis, Martin | Schwingshackl, Michael | Huber-Humer, Marion | Part, Florian
The emissions of tyre wear particles (TWPs) into the environment are increasing and have negative impacts on the environment and human health. The aim of this study was therefore to establish a mass balance for vehicle tyres und TWP emissions in Austria using static material flow analysis, which enabled a quantification of mass flows of rubber including carbon black as the most mass-relevant tyre filler. Vehicle-specific and mileage-dependent emission factors were used to calculate the TWP emissions. The results for the year 2018 indicate that 80% of the tyre rubber remained in use, while 14% was re-treaded, recycled, incinerated or exported as end-of-life tyres and 6% was emitted as TWPs to air, soil or surface water. Of these 21,200 t/y released and dissipative lost TWPs, 6% were microscale, with a possible size between 0.1 and 10 μm, and 0.3% were nanoscale below 0.1 μm. The mass balance on the substance level shows that the TWPs contained 5,500 t/y of carbon black emitted in the form of airborne TWPs (6%) or entering in the soil or surface waters (47% each). Regarding air pollution from road vehicles, about 3,600 t/y were non-exhaust emissions, including tyre, brake and road-surface wear, which contributed to 9% of total dust emissions across Austria. Scenario analysis for 2050 with regard to e-mobility and the European Green Deal reveals that non-exhaust emissions can only be significantly reduced by a general reduction of the mileage or an environmentally friendly tyre design. This modelling approach provides a solid basis for decision makers in traffic planning as well as for chemical risk assessment. However, dynamic models with higher temporal and spatial resolution are needed to predict future mass flows of TWPs and their environmental fate, including their degradation products and possible accumulation effects.
Показать больше [+] Меньше [-]Chlorpyrifos and persistent organic pollutants in feathers of the near threatened Olrog’s Gull in southeastern Buenos Aires Province, Argentina Полный текст
2021
Quadri-Adrogué, Agustina | Seco Pon, Juan Pablo | García, Germán Oscar | Castano, Melina Vanesa | Copello, Sofia | Favero, Marco | Beatriz Miglioranza, Karina Silvia
The use of bird feathers to assess environmental contamination has steadily increased in ecotoxicological monitoring programs over the past decade. The Olrog’s Gull (Larus atlanticus) is a species endemic to the Atlantic coast of southern South America, constituting one of the three threatened gull species listed in the entire American continent. The aim of this study was to assess the exposure to Persistent Organic Pollutants (POPs) and chlorpyrifos in the Near Threatened Olrog’s Gull through the analysis of body feathers sampled at the Mar Chiquita coastal lagoon, the main wintering area of the species in Argentina, controlling for sex and age class. Chlorpyrifos showed the highest concentrations among all contaminants and groups of individuals (X¯ = 263 ng g⁻¹), while among POPs the concentration of organochlorine pesticides was higher than polychlorinated biphenyls and polybrominated diphenyl ethers, likely indicating the current use of these agricultural contaminant in the region. The highest values of total POP concentrations (males X¯ = 280 ng g⁻¹, females X¯ = 301 ng g⁻¹) were found in juvenile gulls, likely as a consequence of the incorporation of pollutants during the breeding season. Subadult and adult birds showed difference between sexes in the concentration of contaminants, with higher levels in males than females. The results highlight the need to include birds of different sex and age classes in order to better understand the variation in pollutants loads. The present study provides relevant information to improve the conservation status of the Olrog’s Gull and new insights about the environmental health of the Mar Chiquita coastal lagoon, Argentina, a MAB-UNESCO World Biosphere Reserve. However, there is a continued need for long-term monitoring programs focusing on this threatened species to understand the effects of pollutants on its population.
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