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Implications of speciation on rare earth element toxicity: A focus on organic matter influence in Daphnia magna standard test
2022
Lachaux, Nicolas | Catrouillet, Charlotte | Marsac, Rémi | Poirier, Laurence | Pain-Devin, Sandrine | Gross, Elisabeth Maria | Giamberini, Laure
Rare earth elements (REE) have become essential in high- and green-technologies. Their increasing use lead to the release of anthropogenic REE into the environment including aquatic systems. The limited data available on the aquatic ecotoxicology of REE indicate their biological effects are highly dependent on their speciation, posing challenges for a reliable environmental risk assessment (ERA). The current study assessed the influence of speciation on the toxicity of neodymium (Nd), gadolinium (Gd) and ytterbium (Yb) in the Daphnia magna mobility inhibition test (ISO 6341:2012). REE toxicity was assessed individually and in ternary mixture, in the absence and presence of dissolved organic matter (DOM). Speciation was predicted by modeling and REE bioaccumulation by D. magna was measured to better understand the relationship between REE speciation and toxicity. DOM decreased significantly the toxicity of Nd, Gd and the mixture towards this freshwater crustacean. This was explained by a lower REE bioaccumulation in the presence of DOM due to REE-DOM complexation, which reduced REE bioavailability. DOM effects on Yb toxicity and bioaccumulation were limited because of Yb precipitation. We show that the way of expressing EC50 values (based on nominal, measured or predicted REE concentrations in solution) drastically changed REE toxicity assessment and that these changes were influenced by REE speciation. This study demonstrates for the first time that REE speciation, and especially REE-DOM complexation, significantly influences REE bioaccumulation and toxicity towards D. magna. Our results have implications for the subsequent ERA of REE.
Afficher plus [+] Moins [-]Recent developments in modification of biochar and its application in soil pollution control and ecoregulation
2022
Bao, Zhijie | Shi, Chunzhen | Tu, Wenying | Li, Lijiao | Li, Qiang
Soil pollution has become a real threat to mankind in the 21st century. On the one hand, soil pollution has reduced the world's arable land area, resulting in the contradiction between the world's population expansion and the shortage of arable land. On the other hand, soil pollution has seriously disrupted the soil ecological balance and significantly affected the biodiversity in the soil. Soil pollutants may further affect the survival, reproduction and health of humans and other organisms through the food chain. Several studies have suggested that biochar has the potential to act as a soil conditioner and to promote crop growth, and is widely used to remove environmental pollutants. Biochar modified by physical, chemical, and biological methods will affect the treatment efficiency of soil pollution, soil quality, soil ecology and interaction with organisms, especially with microorganisms. Therefore, in this review, we summarized several main biochar modification methods and the mechanisms of the modification and introduced the effects of the application of modified biochar to soil pollutant control, soil ecological regulation and soil nutrient regulation. We also introduced some case studies for the development of modified biochars suitable for different soil conditions, which plays a guiding role in the future development and application of modified biochar. In general, this review provides a reference for the green treatment of different soil pollutants by modified biochar and provides data support for the sustainable development of agriculture.
Afficher plus [+] Moins [-]Sublethal effects of metal toxicity and the measure of plant fitness in ecotoxicological experiments
2022
Nowak, Juljan Ignacy | Faure, Nathalie | Glorieux, Cédric | Vile, Denis | Pauwels, Maxime | Frérot, Hélène
Anthropogenic pollution is a major driver of global environmental change. To be properly addressed, the study of the impact of pollutants must consider both lethal effects and sublethal effects on individual fitness. However, measuring fitness remains challenging. In plants, the total number of seeds produced, i.e. the seed set, is traditionally considered, but is not readily accessible. Instead, performance traits related to survival, e.g., vegetative biomass and reproductive success, can be measured, but their correlation with seed set has rarely been investigated. To develop accurate estimates of seed set, relationships among 15 vegetative and reproductive traits were analyzed. For this purpose, Noccaea caerulescens (Brassicaceae), a model plant to study local adaptation to metal-contaminated environments, was used. To investigate putative variation in trait relationships, sampling included several accessions cultivated in contrasting experimental conditions. To test their applicability, selected estimates were used in the first generation of a Laboratory Natural Selection (LNS) experiment exposing experimentally plants to zinc soil pollution. Principal component analyses revealed statistical independence between vegetative and reproductive traits. Traits showing the strongest positive correlation with seed set were the number of non-aborted silicles, and the product of this number and mean silicle length. They thus appeared the most appropriate to document sublethal or fitness effects of environmental contaminants in plant ecotoxicological studies. The relevance of both estimates was confirmed by using them to assess the fitness of parental plants of the first generation of an LNS experiment: the same families consistently displayed the highest or the lowest performance values in two independent experimental metal-exposed populations. Thus, both these fitness estimates could be used to determine the expected number of offspring and the composition of successive generations in further LNS experiments investigating the impact of multi-generational exposure of a plant species to environmental pollution.
Afficher plus [+] Moins [-]Roles of H19/miR-29a-3p/COL1A1 axis in COE-induced lung cancer
2022
Zhang, Heng | Li, Xinmei | Jia, Mengmeng | Ji, Jing | Wu, Zhaoxu | Chen, Xian | Yu, Dianke | Zheng, Yuxin | Zhao, Yanjie
Occupational lung cancer caused by coke oven emissions (COE) has attracted increasing attention, but the mechanism is not clear. Many evidences show ceRNA (competing endogenous RNA) networks play important regulatory roles in cancers. In this study, we aimed to construct and verify the ceRNA regulatory network in the occurrence of COE-induced lung squamous cell carcinoma (LUSC). We performed RNA sequencing with lung bronchial epithelial cell (16HBE) and COE induced malignant transformed cell (Rf). Furthermore, we analyzed RNA sequencing data of LUSC and adjacent tissues in the cancer genome atlas (TCGA) database. Combined our data and TCGA data to determine the differentially expressed lncRNAs, miRNAs, mRNAs. lncBASE, miRDB and miRTarBase were used to predict the binding relationship between lncRNA and miRNA, miRNA and mRNA. Based on these, we construct the ceRNA network. FREMSA, dual-luciferase reporter assay, quantitative real-time PCR (qRT-PCR), western-blot were used to verify the regulatory axis. CCK8 assay, phalloidin staining, p53 detection were used to explore the roles of this axis in the COE induced malignant transformation. Results showed 7 lncRNAs, 7 miRNAs and 146 mRNAs were identified. Among these, we constructed a ceRNA network including 1 lncRNA, 2 miRNAs and 9 mRNAs. Further verification confirmed the trend of lncRNA H19, miR-29a-3p and COL1A1 were consistent with sequencing results. H19 and COL1A1 were significantly higher in Rf than in 16HBE and miR-29a-3p was reverse. Regulatory investigation revealed H19 increased COL1A1 expression by sponging miR-29a-3p. Knockdown of H19, COL1A1 or overexpression of miR-29a-3p in Rf cells could inhibit cell proliferation, increased cell adhesion and p53 level. However, knockdown of H19 while suppressing the miR-29a-3p partially rescue the malignant phenotype of Rf caused by H19. In conclusion, all these indicated H19 functioned as a ceRNA to increase COL1A1 by sponging miR-29a-3p and promoted COE-induced cell malignant transformation.
Afficher plus [+] Moins [-]Polystyrene microplastics inhibit the neurodevelopmental toxicity of mercury in zebrafish (Danio rerio) larvae with size-dependent effects
2022
Wang, Jing | Wu, Jin | Cheng, Haodong | Wang, Yudi | Fang, Yanjun | Wang, Lei | Duan, Zhenghua
Insufficient evidence exists regarding the effects of microplastics (MPs) on the neuronal toxicity of heavy metals in the early stages of organisms. Herein, the effects of micro-polystyrene (μ-PS; 157 μm) and nano-polystyrene (n-PS; 100 nm) particles on the neurodevelopmental toxicity of mercury (Hg) in zebrafish embryos were compared. Zebrafish embryos exposed to Hg at the concentration of 0.1 mg L⁻¹ revealed blood disorders, delayed hatching, and malformations such as pericardial oedema and tail deformity. The length of the larval head was significantly reduced (P < 0.01) and in vivo expression of atoh1a in the cerebellum of neuron-specific transgenic zebrafish Tg(atoh1a:dTomato) larvae was inhibited by 29.46% under the Hg treatment. Most of the toxic effects were inhibited by the combined exposure to μ-PS or n-PS with Hg, and n-PS decreased the neurodevelopmental toxicity of Hg more significantly than μ-PS. Metabolomic analysis revealed that in addition to inhibiting the amino acid metabolism pathway as in the μ-PS+Hg treatment, the n-PS+Hg treatment inhibited unsaturated fatty acid metabolism in zebrafish larvae, likely because of a greater reduction in Hg bioavailability, thus reducing the oxidative damage caused by Hg in the larvae. The combined effects of MPs and heavy metals differ greatly among different species and their targeted effects. We conclude that the combined toxicity mechanisms of MPs and heavy metals require further clarification.
Afficher plus [+] Moins [-]Assessment of red tide risk by integrating CRITIC weight method, TOPSIS-ASSETS method, and Monte Carlo simulation
2022
Chen, Yu-Lin | Shen, Shui-Long | Zhou, Annan
This study proposes a red tide risk assessment method based on intercriteria correlation (CRITIC), technique for order preference by similarity to an ideal solution (TOPSIS), assessment of estuarine trophic status (ASSETS) methods and Monte Carlo simulation (MCS) to calculate the probability of each risk level. The integrated TOPSIS-ASSETS method is used to calculate the risk levels of each year, where index weight is determined by CRITIC method. MCS method is employed to calculate the probability of each risk level. The results showed that level III to level V indicates high possibility of red tides in the case study area (Tolo Harbor). The highest risk rating was level V in 1988. The change of the risk level of red tide is consistent with the real situation of the occurrence of red tide. Another case of the east part of Skagerrak Strait shows that the results of this method are consistent with field situation. When there is an error between the evaluation results and the real situation, MCS can further suggest the probability of error in the evaluation results. Meanwhile, sensitivity analysis was used to test the performance of the evaluation model and two comparative methods. The results show that the proposed risk assessment method has better performance than other methods and can provide an effective risk evaluation for red tide management.
Afficher plus [+] Moins [-]Thermoregulation of Eremias argus alters temperature-dependent toxicity of beta-cyfluthrin: Ecotoxicological effects considering ectotherm behavior traits
2022
Wang, Zikang | Liu, Ran | Zhang, Luyao | Yu, Simin | Nie, Yufan | Deng, Yue | Liu, Rui | Zhu, Wentao | Zhou, Zhiqiang | Diao, Jinling
Risk assessments of the ecotoxicological effects insecticides impose on ectotherms have increasingly considered temperature. However, the changes toxicants induce in thermoregulatory behavioral traits may lead to a divergence of thermal selection and temperature-dependent changes of contaminant toxicity. This study demonstrated the interaction of behavioral thermoregulation and temperature-dependent toxicity of beta-cyfluthrin (BC) in the lizard Eremias argus. Based on the negative relationship between temperature and BC toxicity, seeking a warming environment was assumed to represent a self-rescue behavior (and vice versa). The results showed that BC-treated lizards (0–20 μg/g body weight (bw)) showed such self-rescue behavior, while lizards exposed to an extremely high BC dose (200 μg/g bw) sought a cooler environment. Biochemical assays showed that BC affected neurotransmitter systems, caused oxidative stress, and interfered with ion-transport in the central nervous system. Biomarkers of the cholinergic and glutamatergic system, ion-transport function, and oxidative stress were identified as potential biochemical variables related to thermoregulatory behavior. Apparently, seeking a warmer environment is a survival strategy with the aim to neutralize BC toxicity, while seeking a cooler environment aims to attenuate the harmful effects of metabolic and oxidative stress, and to decelerate internal BC diffusion. This phenomenon could be also explained by the concept of the “cooling trap”, i.e., a behavior where cooler temperatures are sought. This impairs survival after exposure to BC at it has a negative temperature coefficient, derived from a dysfunction of the central nervous system regarding thermoregulation caused by the high dosage of neurotoxicant and resulting temperature maladaptation. Implications of the interaction between thermoregulatory behavior and temperature-dependent toxicity are presented, which may aid further temperature-dependent risk assessments.
Afficher plus [+] Moins [-]A novel human biomonitoring study by semiconductor gas sensors in Exposomics: investigation of health risk in contaminated sites
2022
Longo, Valentina | Forleo, Angiola | Radogna, Antonio Vincenzo | Siciliano, P. (Pietro) | Notari, Tiziana | Pappalardo, Sebastiana | Piscopo, Marina | Montano, Luigi | Capone, Simonetta
Two areas in central-southern Italy Land of Fires in Campania and Valley of Sacco river in Lazio are known to be contaminated sites, the first due to illegal fly-tipping and toxic fires, and the second due to an intensive industrial exploitation done by no-scruple companies and crooked public administration offices with dramatic consequences for environment and resident people. The work is intended to contribute to Human BioMonitoring (HBM) studies conducted in these areas on healthy young male population by a semiconductor gas sensor array trained by SPME-GC/MS. Human semen, blood and urine were investigated. The fingerprinting of the Volatile Organic Compounds (VOCs) by a gas sensors system allowed to discriminate the different contamination of the two areas and was able to predict the chemical concentration of several VOCs identified by GC/MS.
Afficher plus [+] Moins [-]Facile synthesis of electrocatalytically active bismuth oxide nanosheets for detection of palladium traces in pharmaceutical wastewater
2022
Zhao, Ke | Ge, Liya | Lisak, Grzegorz
Current synthesis routes of bismuth oxide nanosheets (BiONS) are relatively complicated, requiring the use of halogens or metalloids. Herein, a facile method to synthesize BiONS without the addition of halogens or other metalloids was developed. The synthesized BiONS were identified to have flake-shaped structures (300–1000 nm in width) with the thickness of 6–10 nm, which were predominantly made of β-Bi₂O₃. Such BiONS were applied to modify the surface of screen-printed carbon electrodes (BiONS-SPCEs) for the development of a robust palladium (Pd²⁺) sensor. After optimizing the electrochemical parameters of the sensor, it was found that the linear sensor response range and limit of detection for Pd²⁺ were 40–400 and 1.4 ppb, respectively. The electrocatalytic activity of the Pd²⁺-sensor was validated in the competing environment of other metal and metalloid ions. Real samples collected during a Pd recovery process from pharmaceutical wastewater were used to verify the application of BiONS-SPCEs in control of palladium recovery process. The quantitative results of post recovery palladium concentrations obtained using BiONS-SPCEs in treated pharmaceutical wastewater samples were in good agreement with those obtained by inductively coupled plasma-optical emission spectrometry (ICP-OES). Thus, such Pd²⁺-sensor provided the possibility of on-site process control of complex industrial samples for obtaining near-instant information that would lead to better management of resources used in the process, and same time assure environmental standards for both recovered products and processed discharge.
Afficher plus [+] Moins [-]The combined supplementation of melatonin and salicylic acid effectively detoxifies arsenic toxicity by modulating phytochelatins and nitrogen metabolism in pepper plants
2022
Kaya, Cengiz | Sarıoglu, Ali | Ashraf, Muhammad | Alyemeni, Mohammed Nasser | Ahmad, Parvaiz
The main objective of the study was to assess if joint application of melatonin (MT, 0.1 mM) and salicylic acid (SA 0.5 mM) could improve tolerance of pepper plants to arsenic (As) as sodium hydrogen arsenate heptahydrate (0.05 mM). The imposition of arsenic stress led to accumulation of As in roots and leaves, and increased contents of leaf proline, phytochelatins, malondialdehyde (MDA) and H₂O₂, but it reduced plant biomass, chlorophylls (Chl), PSII maximum efficiency (Fv/Fm) and leaf water potential. Melatonin and SA applied jointly or alone enhanced nitrogen metabolism by triggering the activities of glutamate synthase, glutamine synthetase, and nitrite reductases and nitrate. In comparison with a single treatment of MT or SA, the joint treatment of MT and SA had better impact on enhancing growth and key biological events and decreasing tissue As content. This clearly shows a cooperative function of both agents in enhancing tolerance to As-toxicity in pepper plants.
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