Affiner votre recherche
Résultats 5961-5970 de 6,541
Urinary bisphenol A, phthalate metabolites, and obesity: do gender and menopausal status matter? Texte intégral
2020
Lim, Jung-eun | Choi, BongKyoo | Jee, Sun Ha
Previous studies of urinary bisphenol A (BPA), phthalate metabolites, and obesity risk have shown inconsistent results. Menopausal status is one of the main factors that affect hormone secretion change in women. In this study, we examined whether urinary BPA and phthalate metabolite levels are associated with obesity and whether the associations differ by sex and menopausal status in a sample of Korean adult populations. We recruited participants at three branches (Yeouido, Gangnam, and Gwanghwamun) of the Korea Medical Institute, a nationwide health check-up center, from 2015 to 2016. Urinary BPA level was measured by high-performance liquid chromatography–tandem mass spectrometry (Agilent 6490 Triple Quad LC-MS/MS; Agilent Technologies, CA, USA). Urinary six phthalate metabolites were analyzed with ultra-high-performance liquid chromatography–tandem mass spectrometry (TSQ Quantum Access Mass; Thermo Fisher Scientific, MA, USA). Participants with body mass index ≥ 25 kg/m² were defined as general obesity group. Men with waist circumference (WC) ≥ 90 cm and women with WC ≥ 85 cm were defined as abdominal obesity group. Age, sex, alcohol intake, smoking, and exercise were considered in multivariate logistic regression models. Among the total of 702 participants, 211 participants were classified into the general obesity group, and 131 participants were classified into the abdominal obesity group. Urinary phthalate metabolite levels were not associated with general and abdominal obesity in men and women. However, in women, urinary BPA concentration was positively associated with abdominal obesity (OR = 1.50, 95% CI 1.00–2.26). Also, the association was stronger in postmenopausal women (OR = 2.23, 1.01–4.92), while it was weak in premenopausal women (OR = 1.31, 0.78–2.20). In this study, urinary BPA concentration was associated with abdominal obesity in women, especially postmenopausal women. Future studies should consider sex and menopausal status when investigating associations between urinary BPA, phthalate metabolites levels, and obesity.
Afficher plus [+] Moins [-]Environmental and economic assessment of Enhanced Landfill Mining in Tehran Texte intégral
2020
Sabour, Mohammad Reza | Alam, Ehsan | Mostafa Hatami, Amir
Landfilling brings many difficulties such as leaching of hazardous substances, methane gas production, loss of land, and natural resources such as groundwater, soil, and minerals. Enhanced landfill mining (ELFM) gives an opportunity to deal with such related problems. This study aimed to assess the environmental performance of ELFM through the application of life cycle assessment (LCA). SimaPro (v 8.5) was utilized to model the consequential life cycle assessment. Moreover, a comprehensive cost-benefit analysis was applied to assess the economic performance along with the Monte Carlo simulation to address the related uncertainties. In addition, the indicator of net present value (NPV) was adopted to understand the economic feasibility of the project. The case study landfill was the closed 55-hectare dumpsite of the municipality of Tehran in Kahrizak due to the need for further landfilling space in the future. The results of this study indicated that ELFM could lead to remarkable environmental benefits compared with the landfill’s current status (the do-nothing scenario). The ELFM project reduced the impact of global warming by 1,759,790 ton CO₂ eq, equaling to 134% reduction in comparison with the do-nothing scenario. Moreover, the potential profitability of the project was calculated to be 370 million $. Among the processes, recycling and thermal treatment of waste significantly dominated the environmental results of the project. Although the research was based on a case study landfill, the methodology can be applied to similar projects worldwide.
Afficher plus [+] Moins [-]Biomimetic detoxifier Prunus cerasifera Ehrh. silver nanoparticles: innate green bullets for morbific pathogens and persistent pollutants Texte intégral
2020
Jaffri, Shaan Bibi | Ahmad, Khuram Shahzad
Silver nanoparticles were fabricated in the presence and absence of light with silver nitrate and aqueous extract of Prunus cerasifera leaf via facile and one-pot green method. P. cerasifera leaf extract reduced and stabilized the nanoparticles with phytometabolites expunging the need for addition of external reducing agents. Optimized silver nanoparticle syntheses was done with variations in leaf extract concentration, time, temperature, and molarity for deciphering the photocatalytic, antifungal, and antibacterial potential of synthesized nanoparticles. Optical, compositional, and morphological analyses of the synthesized nanoparticles were done by UV-visible spectrometry (UV-Vis), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Formation of silver nanoparticles was confirmed firstly through UV-Vis by exhibition of peaks with 400–450 nm. FTIR confirmed the presence of major organic groups responsible for reduction of nanoparticles. AFM confirmed the spherical morphology of the synthesized nanoparticles with remarkable dispersion without any agglomeration. Phytochemical analysis for P. cerasifera leaf metabolites was done by GC-MS. Spherical nanoparticles having a size range of 57–144 nm were obtained with face-centered cubic crystals. The average crystallite size obtained from XRD spectra was 2.34 nm. Enhanced photocatalytic first-order kinetics were obtained for persistent organic pollutants, i.e., crystal violet, methylene blue, and malachite green (R² = 0.99, 0.99, 0.98) in less than 15 min. Biomedical and agricultural significance as an antibiotic drug and utilization as a fungicides substitute was explored against nine resistant microbes. Statistically significant variations were analyzed via one-way analysis of variance (ANOVA) and Kruskal-Wallis test and specific multi comparison tests. Active to highly active inhibition zones manifested the use of biogenic silver nanoparticles as potential candidate for applications in biological arenas and as environmental remediators.
Afficher plus [+] Moins [-]Innovative health risk assessments of heavy metals based on bioaccessibility due to the consumption of traditional animal medicines Texte intégral
2020
Zuo, Tian-Tian | Qu, Hao-Ran | Jin, Hong-Yu | Zhang, Lei | Luo, Fei-Ya | Yu, Kun-Zi | Gao, Fei | Wang, Qi | Sun, Lei | He, Huai-Zhen | Ma, Shuang-Cheng
Few studies reported the extent of heavy metal accumulation in traditional Chinese medicines (TCMs). Currently, oral bioaccessibility of lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), and copper (Cu) present in traditional animal medicines was investigated with physiologically based extraction test–extracted in vitro model. We are the first to develop a health risk assessment strategy by combinational analysis of bioaccessible heavy metal levels to calculate target hazard quotient (THQ), target hazard index (THI) and cancer risk (CR), which has capacity to evaluate the heavy metal associated heath risk of traditional animal medicines. To precisely acquire a realistic risk assessment, questionnaire data was adopted to measure the frequency and duration of the exposure to traditional animal medicines, and the safety factor was highlighted as well. Our data revealed that the bioaccessibility of Hg was the lowest among the five heavy metals. After the adjustment with the bioaccessibility of each heavy metal to target hazard index (THI) values, excitingly, the results manifested that the consumption of traditional animal medicines might not exert an unacceptable health risk in a broad community. In addition, the CR values of As and Pb indicated that the risk of developing cancers was quite lower than their acceptable levels in the clinic.
Afficher plus [+] Moins [-]Evaluation of bisphenol A levels in Nigerian thermal receipts and estimation of daily dermal exposure Texte intégral
2020
Adeyemi, Joseph A. | Gallimberti, Matheus | Olise, Christian C. | Rocha, Bruno Alves | Adedire, Chrs O. | Barbosa Jr, Fernando
Bisphenol A (BPA) is a high production volume chemical that has wide industrial applications, especially as a color developer in thermal papers. The present study focused on the determination of levels of BPA in thermal receipts collected from different locations in Akure, Nigeria, and the estimation of daily intake of BPA through dermal absorption. Thermal receipts were collected from different locations, and the levels of extracted BPA were determined using fluorescence spectroscopy. The daily intake of BPA was estimated, and the amount was compared with the reference value. BPA was detected in all the samples analyzed with levels ranging from 1.50 to 3.16 mg/g. These values were lower than the values detected in thermal receipts obtained from other countries. The estimated mean daily intakes of BPA by dermal absorption due to handling of thermal receipts were 0.20 and 9.89 μg/day for the general population and the occupationally exposed individuals, respectively, and were much lower than the reference value of 50 μg/kg bw/day provided by the European Food Safety Authority. This indicates that dermal exposure to BPA is not a serious health risk to the population.
Afficher plus [+] Moins [-]Environmental, mechanical, and biochemical benefits of water hyacinth (Eichhornia crassipes) Texte intégral
2020
Adelodun, Adedeji Adebukola | Hassan, Usman Olamide | Nwachuckwu, Victor Oluwatobi
Water hyacinth (WH) has high tolerance in extreme environmental conditions. Here, we examined the potentials of WH (Eichhornia crassipes (Mart) solms) to remove excess nutrients from sewage wastewater. We used four prototypes of water systems: prototypes A (WH + underlay water) and C (WH + sewage water), whereas prototypes B and D were experimental control for A and C, respectively. For prototype A, the percentage removal efficiencies (%Rₑ) for nitrate and phosphate achieved were 75.12 ± 4.22% and 78.90 ± 8.72%, respectively, with a pH increase from 6.29 to 7.69; whereas for prototype C, the values were 54.7 ± 8.11% and 86.10 ± 7.34%, respectively, with a pH decrease from 8.13 to 7.15. For the 3-week retention time, the biomass weight increased in both prototype A (33.26%; [Formula: see text] rate = 15.46 g/week) and prototype C (26.43%; [Formula: see text] rate = 12.54 g/week). Further, the respective mechanical strength and nutritional values of the WH’s fiber and the organic extracts were examined. The air-dried WH stem showed an average tensile stress of 0.04 MPa on a load at maximum stress of 137.1 N. By comparison, a strand of WH has a tensile strength of 14 MPa, inferior to 15, 61, and 400 MPa shown by timber, wood, and steel, respectively. However, by knitting, four strands of WH yielded a much-improved tensile strength of 315 MPa. Finally, a gas chromatography-mass spectrometer analysis of the plant’s extract showed that it contains 35.51% oleic acid, a nutritional extract of high value. Thence, we established a profound economic significance of WH, a macrophyte with latent immense benefits.
Afficher plus [+] Moins [-]Ferulic acid prevents oxidative stress, inflammation, and liver injury via upregulation of Nrf2/HO-1 signaling in methotrexate-induced rats Texte intégral
2020
Mahmoud, Ayman M. | Hussein, Omnia E. | Hozayen, Walaa G. | Bin-Jumah, May | Abd El-Twab, Sanaa M.
Liver injury is one of the adverse effects of methotrexate (MTX). Ferulic acid (FA) is an antioxidant phytochemical that confers hepatoprotective efficacy; however, its effect against MTX hepatotoxicity remains unexplored. This study investigated the role of FA in modulating oxidative stress, inflammation, Nrf2/HO-1 signaling, and PPARγ in MTX-administered rats. Following oral FA supplementation for 15 days, rats received a single dose of MTX at day 16 and samples were collected at day 19. MTX provoked multiple histological manifestations, including degenerative changes, steatosis, inflammatory cells infiltration and hemorrhage, and altered serum transaminases, bilirubin, and albumin. Reactive oxygen species, lipid peroxidation, and nitric oxide were increased in the liver of rats that received MTX. FA prevented all histological alterations, ameliorated liver function markers, suppressed oxidative stress, and boosted antioxidants in MTX-induced rats. FA reduced serum TNF-α and IL-1β, and hepatic NF-κB p65, Bax, and caspase-3, whereas increased Bcl-2, Nrf2, NQO1, HO-1, and PPARγ. In conclusion, FA prevented MTX hepatotoxicity by activating Nrf2/HO-1 signaling and PPARγ, and attenuating oxidative stress, inflammation, and cell death.
Afficher plus [+] Moins [-]Determining the carrying capacity and environmental risks of livestock and poultry breeding in coastal areas of eastern China: an empirical model Texte intégral
2020
Li, Jianguo | Liu, Lili
The scale of regional livestock and poultry breeding (LPB) is generally not determined by the supporting capacity (fodder supply), but by the environmental carrying capacity of wastes from the LPB. The soil’s own nutrient-supplying capacity used to be overlooked, which consequently produced an inaccurate result of carrying capacity estimation of the LPB. An empirical method was, therefore, employed to evaluate the soil’s own nutrient-supplying capacity and further determine the carrying capacity and environmental risks of the LPB accurately. Thirteen counties along the coast of Jiangsu were selected to conduct this study, according to the framework of planting-breeding balance. Our results indicate that, including the soil’s own nutrient-supplying capacity in the estimation of the carrying capacity of the LPB, it can reduce the original carrying capacity by 50%. This suggests that our empirical method can significantly increase the accuracy of estimating the carrying capacity of the LPB. The carrying capacity of the LPB in the study area varies from 1.5 to 48.08 pigs/hm², with a mean of 14 pigs/hm² based on phosphorus (P) balance. Furthermore, four sub-regions (Ganyu, Dongtai, Dafeng, and Guannan) that have a high P pollution risk should focus on controlling the scale of the LPB. The nitrogen (N) pollution risk in the study area is generally low. Results suggest that the soil’s own nutrient-supplying capacity plays an important role in estimating the carrying capacity of the LPB accurately. This study can provide insights on reducing environmental risks of the LPB, which may be beneficial for decision makers.
Afficher plus [+] Moins [-]How do FDI and technical innovation affect environmental quality? Evidence from China Texte intégral
2020
Hao, Yu | Wu, Yerui | Wu, Haitao | Ren, Siyu
Foreign direct investment (FDI) is an important driving force for economic growth and technological innovation, but it also brings environmental pollution problems along with economic development. From the perspective of technological innovation, the impact of FDI on China’s environmental pollution deserves further study. With the spatial econometric tools employed to account for the potential spatial dependence of environmental pollution, this study uses the panel data of 30 province-level units in China from 1998 to 2016 to investigate the impact of FDI and technological innovation on environmental pollution. The results show that increased FDI can reduce environmental pollution, confirming the existence of the “pollution halo hypothesis”; technological innovation can reduce the emissions of sulfur dioxide and smoke dust but increase the chemical oxygen demand. Therefore, vigorous introduction of foreign capital is good for sustainable development for government, but it is also necessary to pay attention to screening and identifying environment-friendly enterprises with advanced production technology and management experience and to reject high-pollution and high-energy-consuming enterprises eliminated by developed countries.
Afficher plus [+] Moins [-]Plastic floating debris along a summer-winter estuarine environmental gradient in a coastal lagoon: how does plastic debris arrive in a conservation unit? Texte intégral
2020
Lorenzi, Luciano | Reginato, Bruna Conte | Mayer, Devon Gebauer | Dantas, David Valença
Improper management of plastic waste is an important contributor to the pollution in water bodies. However, how floating plastic debris is transported to coastal lagoons and marine conservation units is still poorly understood. This work determined the level of contamination due to floating plastic debris in Acaraí Lagoon by establishing density distribution patterns along the lagoon ecocline in the winter and summer. Four areas were chosen that followed the estuarine gradient of the lagoon (external, lower, middle, and upper), and in each area, three samples of were collected by trawling with a plankton net. The plastic debris was classified into paint fragments, hard solids, plastic filaments, and soft plastics, and the plastic debris density and surface area were determined in each sampling area. The concentrations of the plastics in the downstream and upstream areas resulted from the high density of debris that occurred during the winter due to the absence of rain and the entry of coastal waters into the lagoon. The reduced abundance and surface area of the plastics in the summer were related to the substantial output of water from the interior of the lagoon to the mouth of the lagoon due to high rainfall during this season. The absence of plastic waste management actions and developed areas at the mouth of the lagoon that were associated with the spatial and temporal fluctuations in the environmental variables favored the occurrence and high abundance of plastic debris in the water column, contaminating the entire system of Acaraí State Park.
Afficher plus [+] Moins [-]