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Disruption of thyroid hormone regulated proteins and gene expression by polychlorinated biphenyls, polybrominated diphenyl ethers and new flame retardants in residents of an e-waste region Texte intégral
2019
Guo, Ling-Chuan | Yu, Shengbing | Wu, De | Huang, Jinxu | Liu, Tao | Xiao, Jianpeng | Huang, Weixiong | Gao, Yanhong | Li, Xing | Zeng, Weilin | Rutherford, Shannon | Ma, Wenjun | Zhang, Yonghui | Lin, Lifeng
Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and new flame retardants (NFRs) are known thyroid hormone (TH) disruptors, but their disrupting mechanisms in humans are not completely understood. In this study, we aimed to explore the disrupting mechanisms of the aforementioned chemicals via examining TH-regulated proteins and gene expression in human serum. Adult participants from an e-waste dismantling (exposed group) and a control region (control group) in South China provided blood samples for the research. Some compounds of PCBs, PBDEs, and NFRs showed strong binding affinity to the thyroid-stimulating hormone (TSH), thyroglobulin, thyroxine-binding globulin (TBG), gene expression of TH receptor α (TRα) and β, and iodothyronine deiodinase I (ID1). The highly exposed individuals had lower levels of TBG, TSH, and expression of TRα, but higher expression of ID1 than those of the control group. The disruption of TH-regulated proteins and gene expression suggested the exertion of different and, at times, even contradictory effects on TH disruption. However, no statistically significant difference was found in the TH levels between the exposed and the control group, implying that the TH disruption induced by these chemicals depends on the combined influence of multiple mechanisms. Gene expression appears to be an effective approach for investigations of TH disruption and the potential health effects.
Afficher plus [+] Moins [-]Understanding plastics pollution: The role of economic development and technological research Texte intégral
2019
Barnes, Stuart J.
Our world is awash with plastic. The massive increase in plastics production, combined with a shift to single-use, disposable plastics and widespread mismanagement of plastic waste, has created a huge “tragedy of the commons” (Hardin, 1968) in our oceans, seas and waterways. Plastics pollution is now a global externality that damages ecosystems, curtails biodiversity and ultimately has the potential to affect everyone on the planet. Although waste output is often modelled separately from environmental pollution in research, in the case of plastics, the waste problem has become one of global pollution. In this paper, we model the relationship between mismanaged plastic waste1 and income per capita for 151 countries, and for the first time find empirical support for the environmental Kuznets curve using plastics pollution data. Further, we find support for the hypothesis that a key instrument for reducing plastics pollution is investment in scientific and technological research. The paper concludes with a discussion of the results, limitations, and implications for future research and practice.
Afficher plus [+] Moins [-]Cell-based assays seem not to accurately predict fish short-term toxicity of pesticides Texte intégral
2019
Rodrigues, Elsa T. | Varela, Ana T. | Pardal, Miguel A. | Oliveira, Paulo J.
A key action of current aquatic environmental sciences is the determination of concentration-response assessments to quantitatively measure the risk of pollutants, and fish lethal tests are still a regulatory requirement for assessing the environmental risk of both new and existing substances in the aquatic compartment. However, animal health and welfare aspects, as well as the time and resources required to support fish lethal testing, stimulate research for alternative in vitro methods, and cell-based assays are considered as one such alternative. The first goal of the present study was to compile existing fish short-term toxicity and cell toxicity data of pesticides through a scientific literature search, and relate in vivo and in vitro results to identify sensitive cell models, mammalian-, fish- or arthropod-derived. Discovering cell models which are sensitive is of great importance, since the risk of false negatives, believed to be the main limitation of cell-based assays as an alternative to fish tests, may decrease. As to the second goal, this study also determined and compared cell toxicity results for 12 pesticides using rat cardiomyoblast H9c2(2–1) cells with the corresponding fish LC₅₀,₉₆ₕ (50% lethal concentration at 96 h of exposure) values collected in literature. On the whole, the in vivo/in vitro ratio was obtained for 50 pesticides belonging to 23 groups, and presented only 27% of positive results, thus confirming the low sensitivity of cell-based assays in relation to fish lethal data for pesticides. In general, cell-based assays still do not seem to be an alternative to the regulatory short-term fish assay for pesticides, making further studies necessary.
Afficher plus [+] Moins [-]Distribution of volatile organic compounds over Indian subcontinent during winter: WRF-chem simulation versus observations Texte intégral
2019
Chutia, Lakhima | Ojha, Narendra | Girach, Imran A. | Sahu, Lokesh K. | Alvarado, Leonardo M.A. | Burrows, J. P. (John P.) | Pathak, Binita | Bhuyan, Pradip Kumar
We investigate the distribution of volatile organic compounds (VOCs) over Indian subcontinent during a winter month of January 2011 combining the regional model WRF-Chem (Weather Research and Forecasting model coupled with Chemistry) with ground- and space-based observations and chemical reanalysis. WRF-Chem simulated VOCs are found to be comparable with ground-based observations over contrasting environments of the Indian subcontinent. WRF-Chem results reveal the elevated levels of VOCs (e. g. propane) over the Indo-Gangetic Plain (16 ppbv), followed by the Northeast region (9.1 ppbv) in comparison with other parts of the Indian subcontinent (1.3–8.2 ppbv). Higher relative abundances of propane (27–31%) and ethane (13–17%) are simulated across the Indian subcontinent. WRF-Chem simulated formaldehyde and glyoxal show the western coast, Eastern India and the Indo-Gangetic Plain as the regional hotspots, in a qualitative agreement with the MACC (Monitoring Atmospheric Composition and Climate) reanalysis and satellite-based observations. Lower values of RGF (ratio of glyoxal to formaldehyde <0.04) suggest dominant influences of the anthropogenic emissions on the distribution of VOCs over Indian subcontinent, except the northeastern region where higher RGF (∼0.06) indicates the role of biogenic emissions, in addition to anthropogenic emissions. Analysis of HCHO/NO₂ ratio shows a NOₓ-limited ozone production over India, with a NOₓ-to-VOC transition regime over central India and IGP. The study highlights a need to initiate in situ observations of VOCs over regional hotspots (Northeast, Central India, and the western coast) based on WRF-Chem results, where different satellite-based observations differ significantly.
Afficher plus [+] Moins [-]Distribution, availability and translocation of heavy metals in soil-oilseed rape (Brassica napus L.) system related to soil properties Texte intégral
2019
Cao, Xuerui | Wang, Xiaozi | Tong, Wenbin | Gurajala, Hanumanth Kumar | Lu, Min | Hamid, Yasir | Feng, Ying | He, Zhenli | Yang, Xiaoe
Heavy metals contamination in agricultural soil has become a worldwide problem, and soil characteristics modulate metal availability in soils. Four field experiments were conducted simultaneously to evaluate concentration and distribution of cadmium (Cd) and lead (Pb) in 39 oilseed rape cultivars at four agricultural locations with different contamination levels of Cd and Pb, as well as the influence of soil characteristics together with soil total and bioavailable Cd and Pb concentration on metal transfer from soil to oilseed rape. Shoot concentrations of Cd and Pb in oilseed rape cultivars ranged from 0.09 to 3.18 and from 0.01 to 10.5 mg kg⁻¹ across four sites. For most cultivars, Cd concentration in root or shoot were higher than pod and lowest in seed, while the highest Pb concentration was observed in root followed by shoot and seed. Stepwise multiple linear regression analysis allows for a better estimation of Cd and Pb concentration in oilseed rape while taking soil properties into consideration. The results demonstrated that Cd and Pb concentration in oilseed rape were correlated with soil organic matter (OM), cation exchange capacity (CEC), available phosphorus (AP), available potassium (AK), sand, soil total and available Cd and Pb concentration, and R² varied from 0.993 to 0.999 (P < 0.05). The Cd and Pb levels found in oilseed rape indicated its phytoextraction potential for Cd and Pb co-contaminated agricultural soils in winter without stopping agricultural activities.
Afficher plus [+] Moins [-]Microplastics in the crustaceans Nephrops norvegicus and Aristeus antennatus: Flagship species for deep-sea environments? Texte intégral
2019
Cau, Alessandro | Avio, Carlo Giacomo | Dessì, Claudia | Follesa, Maria Cristina | Moccia, Davide | Regoli, Francesco | Pusceddu, Antonio
Ingestion of microplastics (MPs) has been documented in several marine organisms, but their occurrence in deep-sea species remains almost unknown. In this study, MPs were investigated in two economically and ecologically key crustaceans of the Mediterranean Sea, the Norwegian lobster Nephrops norvegicus and the shrimp Aristeus antennatus. Both the species were collected from 14 sites around Sardinia Island, at depths comprised between 270 and 660 m. A total of 89 and 63 stomachs were analysed for N. norvegicus and A. antennatus respectively, and more than 2,000 MPs-like particles were extracted and sorted for identification and characterization by μFT-IR. In N. norvegicus, 83% of the specimens contained MPs, with an average abundance of 5.5 ± 0.8 MPs individual−1, while A. antennatus showed a lower frequency of ingestion (67%) and a lower mean number of MPs (1.66 ± 0.1 MPs individual−1). Composition and size of particles differed significantly between the two species. The non-selective feeding strategy of N. norvegicus could explain the 3–5 folds higher numbers of MPs in its stomach, which were mostly composed of films and fragments derived by polyethylene and polypropylene single-use plastic items. Contrarily, most MPs in the stomachs of A. antennatus were polyester filaments. The MPs abundance observed in N. norvegicus is among the highest detected in Mediterranean species considering both fish and invertebrates species, and provides novel insights on MPs bioavailability in deep-sea habitats. The overall results suggest that both N. norvegicus and A. antennatus, easily available in common fishery markets, could be valuable bioindicators and flagship species for plastic contamination in the deep-sea.
Afficher plus [+] Moins [-]A comparative study on biochar properties and Cd adsorption behavior under effects of ageing processes of leaching, acidification and oxidation Texte intégral
2019
Chang, Ruihai | Sohi, Saran P. | Jing, Fanqi | Liu, Yuyan | Chen, Jiawei
Biochar has potential to control the bioavailability and migration of potentially toxic heavy metals in soil by adsorption. Natural ageing in the environment may change the physicochemical properties and adsorption function of biochar over the long-term. The present study compared the effects of different simulated ageing treatments on Cd adsorption of high and low temperature biochar from straw of corn (Zea mays). Fresh and aged biochars were systematically characterized by elemental analysis, FTIR, XPS, Zeta, SEM-EDS, XRD and the composition of their mineral ash. The adsorption of Cd to fresh and aged biochars was then assessed under the influence of pH. Drawing the results together the effects of ageing on the extent and mode of Cd adsorption could be elucidated. The results showed that the adsorption capacity of fresh biochar produced at 650 °C was higher than of biochar made at 350 °C, and that mineral co-precipitation plays a dominant role in Cd sorption. Leaching removed organic and inorganic ash components from biochars, markedly diminishing the capacity of the high temperature biochar to adsorb Cd. The adsorption performance of the low temperature biochar was dependent on surface complexation. The adsorption capacity of low-temperature biochar was markedly enhanced by oxygen-containing functional groups formed through acidification and oxidation. The long-term benefits of biochar in the management of polluted soil require a rethink, considering the contrasting ageing behavior of different temperature biochar and their response to different ageing environments.
Afficher plus [+] Moins [-]Speciation and location of arsenic and antimony in rice samples around antimony mining area Texte intégral
2019
Wu, Tong-Liang | Cui, Xiao-Dan | Cui, Pei-Xin | Ata-Ul-Karim, Syed Tahir | Sun, Qian | Liu, Cun | Fan, Ting-Ting | Gong, Hua | Zhou, Dong-Mei | Wang, Yurun
Arsenic (As) and antimony (Sb) are considered as priority environmental pollutants and their accumulation in crop plants particularly in rice has posed a great health risk. This study endeavored to investigate As and Sb contents in paired soil-rice samples obtained from Xikuangshan, the world largest active Sb mining region, situated in China, and to investigate As speciation and location in rice grains. The soil and rice samples were analyzed by coupling the wet chemistry, laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), synchrotron-based micro X-ray fluorescence mapping (μ-XRF) and micro X-ray absorption near-edge structure (μ-XANES) spectroscopy. The results of field survey indicated that the paddy soil in the region was co-polluted by Sb (5.91–322.35 mg kg−1) and As (0.01–57.21 mg kg−1). Despite the higher Sb concentration in the soil, rice accumulated more As than Sb indicating the higher phytoavailability of As. Dimethylarsinic acid (DMA) was the predominant species (>60% on average) in the rice grains while the percentage of inorganic As species was 19%–63%. The μ-XRF mapping of the grain section revealed that the most of As was distributed and concentrated in rice husk, bran and embryo. Sb was distributed similarly to As but was not in the endosperm of rice grain based on LA-ICP-MS. The present results deepened our understanding of the As/Sb co-pollution and their association with the agricultural-product safety in the vicinity of Sb mining area.
Afficher plus [+] Moins [-]Synergistic effects of key parameters on the fate of antibiotic resistance genes during swine manure composting Texte intégral
2019
Lu, Xiao-Ming | Lu, Peng-Zhen
Livestock manure is a reservoir of antibiotic resistance genes (ARGs), posing a potential risk to environment and human health. However, there has been no optimization study about the comprehensive composting treatment for livestock manure ARGs based on multiple operation factors. In this study, anaerobic composting of swine manure in light was conducted under different combined conditions of composting time, temperature, water content, pH, heavy metal passivators and wheat straw. The diversity and relative abundance of ARGs in the compost were detected using high throughput quantitative real-time PCR, and the concentrations of antibiotics and heavy metals were determined. The results showed that under the optimized conditions (composting time, 30 d; temperature, 50 °C; water content, 50%; pH 9.0; heavy metal passivators and wheat straw), compared with the control, the detected number of ARGs and mobile genetic elements in the compost was reduced by 45% and 27.3%, and their relative abundance decreased by 33.9% and 36.9%, respectively. Moreover, the exchangeable heavy metal content of the compost declined by 34.7–57.1%, and the antibiotic level decreased by 28.8–77.8%. This study proposes that synergistic effects of key parameters can effectively mitigate the combined contamination of ARGs, antibiotics, and heavy metals in swine manure.Optimized parameters (anaerobic composting time 30 d, temperature 50 °C, water content 50%, pH 9.0) effectively mitigated the combined pollution of ARGs, antibiotics, and heavy metals in swine manure.
Afficher plus [+] Moins [-]Vertical profiles and distributions of aqueous endocrine-disrupting chemicals in different matrices from the Pearl River Delta and the influence of environmental factors Texte intégral
2019
Gong, Jian | Ran, Yong | Zhang, Dainan | Chen, Diyun | Li, Haiyan | Huang, Youda
The occurrence and distributions of selected endocrine-disrupting chemicals (EDCs), along with related environmental factors, were investigated in two rivers and six reservoirs in the Pearl River Delta. The vertical profiles of aqueous 4-tert-octylphenol (OP), 4-nonylphenol (NP), and estrone (E1) were constant, with little change in concentration between the surface and the river bottom, while higher aqueous concentrations of bisphenol A (BPA) were found in the bottom layers of the rivers. OP and NP in suspended particulate matter (SPM) were transferred from the surface to the bed layer, ultimately accumulating in the sediment. However, the particulate profiles of BPA and E1 both featured increases from the surface to the bottom layers and attenuation in the river bed. Dissolved oxygen (DO), water temperature, and pH were negatively correlated with the EDC concentrations, and negative relationships between DO and distribution coefficient (Kd) values for OP and NP were found as well. This indicated that these environmental parameters were primarily responsible for the EDC vertical distribution and SPM-water partitioning in the rivers. Positive relationships were observed between chlorophyll a and EDCs in the particulate phase, and the algae/water Kd values for EDCs in reservoirs were comparable to the SPM/water and sediment/water Kd values from the rivers. These results suggest that algae played an important role in regulating the distribution of EDCs in surface waters. Moreover, relationships between UV absorbance and EDCs revealed that π-π interactions were among the dissolved organic carbon (DOC)-EDC binding mechanisms and that DOC fractions with higher degrees of aromaticity and humification possessed higher affinities towards EDCs.
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