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Biomphalaria alexandrina: a model organism for assessing the endocrine disrupting effect of 17β-estradiol
2019
Abu El Einin, Hanaa M. | Ali, Rasha E. | Gad El-Karim, Rasha M. | Youssef, Alaa A. | Abdel-Hamid, Hoda | Habib, Mohamed R.
A wide range of endocrine disruptor compounds are routinely discharged to the ecosystem. Water contaminated with these compounds has a potential effect on the reproductive physiology of aquatic organisms as well as humans. In the present study, we tested the effect of the steroid estrogen, 17β-estradiol, on Biomphalaria alexandrina, a snail species that is widely distributed in Egypt and that acts as an intermediate host for the human blood fluke, Schistosoma mansoni. The effects of exposure to 0.3 mg/L and 1 mg/L 17β-estradiol on fecundity (MX) and reproductive rate (R₀) of B. alexandrina were recorded. In addition, levels of steroid sex hormones and antioxidants in the hemolymph and ovotestis (OT) of exposed snails were measured. Histopathological changes in the OT of B. alexandrina were also investigated. Exposure to 0.3 mg/L and 1 mg/L 17β-estradiol caused a significant increase in the number of egg masses per snail after 3 weeks and 1 week of exposure for the two tested concentrations compared with unexposed controls. An increase in the levels of progesterone hormone was recorded in the hemolymph of exposed snails in comparison with unexposed controls. Additionally, levels of the antioxidant enzyme glutathione (GSH) were increased in the hemolymph and OT tissues of snails after 2 and 4 weeks of exposure. Histopathological sections in the OT revealed an increase in the oocyte and a decrease in the sperm densities after 2 weeks and this effect was restored to normal conditions after 4 weeks of exposure to both tested concentrations. The current results indicate that B. alexandrina is sensitive to 17β-estradiol and can therefore be used as bioindicator and model organism for the assessment of water pollution with endocrine disruptor compounds.
Show more [+] Less [-]Indirect source apportionment of methyl mercaptan using CMB and PMF models: a case study near a refining and petrochemical plant
2019
Feng, Jingjing | Gao, Song | Fu, Qingyan | Chen, Xiaojia | Chen, Xiaolin | Han, Demin | Cheng Jinping,
Identifying the sources of volatile organic compounds (VOCs) is key to air quality control and pollution prevention. Though receptor models have been widely used in source apportionment of VOCs, they are not applicable to identify the potential source of labile species. In this study, the potential source of methyl mercaptan (MeSH) near a large refining and petrochemical plant was identified using an indirect method. When wind directions were controlled, the study period was separated into two subperiods depending on the detection of MeSH. Relative contributions from potential sources were predicted by chemical mass balance model and positive matrix factorization model based on ambient concentrations of sulfur-free compounds. Both models predicted that petroleum refinery and petrochemical production were the dominant sources of VOCs in the study area. When MeSH was detected, the relative contribution from gasoline, liquefied petroleum gas, or crude oil increased by 7.4 to 26.8% point, depending on wind direction and the predictive model used, suggesting a close relationship between MeSH and the emission from petroleum refinery. Consistent with the indirect source apportionment, among the coexisting VOCs, MeSH was most highly correlated or associated with ethane, propane, isobutane, cis-2-pentente, and isoprene, which are major components of the products or by-products of petrochemical refining processes.
Show more [+] Less [-]Strong insecticidal potential of methanol extract of Ferulago trifida fruits against Anopheles stephensi as malaria vector
2019
Goodarzi, Saied | Tavakoli, Saeed | Abai, Mohammad Reza | Amīnī, Zahrā | Vatandoost, Hassan | Yassa, Narguess | Hadjiakhoondi, Abbas | Tofighi, Zahra
Many researchers have focused on controlling pest insects and vectors by natural products because of their low environmental pollution. The present study was conducted to evaluate the antioxidant and larvicidal activities of chloroform and methanol extracts of the leaves, fruits, roots, and isolated coumarin compounds (prantschimgin, oxypeucedanin, and 6-hydroxymethylherniarin) of Ferulago trifida from the Apiaceae family against Anopheles stephensi as one of the main malaria vectors. For insecticidal evaluation, A. stephensi larvae were exposed to different concentrations of the extracts and pure compounds (0.625–1280 ppm) according to the WHO protocol. The mortality percentages were measured 24 h after treatment and lethal concentration values were calculated. In addition, radical scavenging activities of the mentioned extracts and compounds were measured by the DPPH method. The methanol extract of fruits showed potent insecticidal properties with LC₅₀ and LC₉₀ values of 2.94 and 18.12 ppm, respectively. The chloroform extracts of the fruits and leaves were the second and third extracts with larvicidal effects. Among pure compounds, only oxypeucedanin showed moderate toxicity against A. stephensi with LC₅₀ and LC₉₀ values of 116.54 and 346.41 ppm, respectively. The antioxidant activities of the methanol extracts of leaves and fruits were stronger than other extracts with IC₅₀ values of 155.83 and 159.32 ppm, respectively. In conclusion, the methanol extract of F. trifida fruits can be used as a potent bio-insecticide in green control programs of mosquitoes, especially A. stephensi.
Show more [+] Less [-]Sono-advanced Fenton-like degradation of aromatic amines in textile dyeing sludge: efficiency and mechanisms
2019
Zou, Haiyuan | Ning, Xun-an | Wang, Yi | Sun, Jian | Hong, Yanxiang
In this paper, a novel strategy integrating ultrasound (US) with a Fenton-like (zero-valent iron/EDTA/air, ZEA) process was proposed for the removal of the refractory and carcinogenic aromatic amines (AAs) in textile dyeing sludge for the first time. The operating condition was optimized as 1.08 W/cm³ ultrasonic density, 15 g/L ZVI, and 1.0 mM EDTA, which could reach degradation efficiencies of 51.79% in US, 72.88% in ZEA, and 92.40% in US/ZEA system after 90-min reaction. Quenching experiments showed that electron transfer reactions generated by the iron ligands in ZEA brought about various reactive oxidative species (ROS), in which Fe (IV), O₂˙⁻, and ˙OH dominated the degradation. US induced sludge disintegration by ultrasonic shear, proven by particle size decrease and supernatant organic matter upsurge, which helps ROS contact with those pollutants in the sludge cavities. Besides, US facilitated the iron redox cycle for oxygen activation by promoting the corrosion of ZVI and stripping considerable ferric ions from sludge iron oxides which were verified by SEM, XRF, and XPS. Graphical abstract
Show more [+] Less [-]Degradation of diethyl phthalate (DEP) by vacuum ultraviolet process: influencing factors, oxidation products, and toxicity assessment
2019
Wu, Yangtao | Deng, Lin | Bu, Lingjun | Zhu, Shumin | Shi, Zhou | Zhou, Shiqing
The vacuum ultraviolet (VUV) process, which can directly produce hydroxyl radical from water, is considered to be a promising oxidation process in degrading contaminants of emerging concern, because of no need for extra reagents. In this study, the influencing factors and mechanism for degradation of diethyl phthalate (DEP) by the VUV process were investigated. The effects of irradiation intensity, inorganic anions, natural organic matter (NOM), and H₂O₂ dosage on the performance of VUV process were evaluated. The results showed that DEP could be more efficiently degraded by the VUV process compared with ultraviolet (UV)-254-nm irradiation. The presence of HCO₃⁻, NO₃⁻ and NOM in the aqueous solutions inhibited the degradation of DEP to a different degree, mainly by competing hydroxyl radicals (HO•) with DEP. Degradation rate and removal efficiency of DEP by VUV process significantly enhanced with the addition of H₂O₂, while excess H₂O₂ dosage could inhibit the DEP degradation. Moreover, based on the identified seven oxidation byproducts and their time-dependent evolution profiles, a possible pathway for DEP degradation during the VUV process was proposed. Finally, the ecotoxicity of DEP and its oxidation byproducts reduced overall according to the calculated results from Ecological Structure Activity Relationships (ECOSAR) program. The electrical energy per order (EE/O) was also assessed to analysis the energy cost of the DEP degradation in the VUV process. Our work showed the VUV process could be an alternative and environmental friendly technology for removing contaminants in water.
Show more [+] Less [-]Effect of prenatal PFOS exposure on liver cell function in neonatal mice
2019
Liang, Xiaoliu | Xie, Guojie | Wu, Xinmou | Su, Min | Yang, Bin
Perfluorooctane sulfonate (PFOS), a hepatotoxic pollutant, is detected in the human cord blood, and it may induce health risk to an embryo. In this study, we established intrauterine exposure to PFOS in mice to evaluate potential impacts of PFOS on postnatal day 1 (PND1) offspring through conducting biochemical tests, quantitative PCR, and immunostaining. As results, PFOS-exposed maternal mice showed marked hepatomegaly and induced liver steatosis in a high dose of 5 mg PFOS/kg. In PND1 mice, intrahepatic contents of triglyceride, total cholesterol, and LDL were elevated by high-dose PFOS exposure, while intracellular HDL content was decreased. As shown in quantitative PCR, functional messenger RNAs of cytochrome P4A14 (CYP4A14) for fatty acid oxidation, CD36 for hepatic fatty acid uptake, and apolipoprotein B100 (APOB) and fibroblast growth factor 21 (FGF21) for hepatic export of lipids in PND1 livers were changed when compared to those in PFOS-free controls. In further validations, immunofluorescence stains showed that hepatic CYP4A14 and CD36 immunoreactive cells were increased in PFOS-exposed PND1 mice. In addition, reduced immunofluorescence-positive cells of APOB and FGF21 were observed in PND1 livers. Collectively, these preliminary findings demonstrate that prenatal exposure to PFOS may affect lipid metabolism in liver cells of PND1 mice.
Show more [+] Less [-]Influences of fine-grained NaCl particles on performance and denitration efficiency of activated carbon during sintering flue gas purification process
2019
Fan, Xiaohui | Yao, Jiawen | Gan, Min | Lv, Wei | Ji, Zhiyun | Chen, Xuling | Wong, Guojing | Tang, Qingyu
Alkali metal chlorides emitted from sintering flue gas are easily adsorbed on the surface of activated carbon (AC) in the purification process. In this paper, NaCl particles adsorbing onto AC were simulated by impregnation method, and the size and morphology of NaCl particles were similar to those of NaCl-PM₁₀ emitted from sintering flue gas. With the adsorption of NaCl particles, 2–10-μm pores of AC were filled, and the specific surface area of AC decreased. But NaCl led to the increase of acidic functional groups on the surface of AC. When 0.75 wt% NaCl was adsorbed, it was beneficial for AC catalytic denitration (de-NOx), because the chemical reaction was strengthened by acidic functional groups, so it showed a certain promotion of de-NOx efficiency. As 1.5 wt% NaCl and 3 wt% NaCl were adsorbed, NaCl had an inhibitory effect on AC de-NOx, which was because the specific surface area of AC decreased, and the prevention of physical adsorption played a major role. As a result, the de-NOx efficiency of AC adsorbed with 3 wt% NaCl decreased from 40.59 to 23.02% at 150 °C. Therefore, the absorption of NaCl fine particles on AC should not exceed 0.75 wt%.
Show more [+] Less [-]The possible global hazard of cell phone radiation on thyroid cells and hormones: a systematic review of evidences
2019
Asl, Jafar Fatahi | Larijani, Bagher | Zakerkish, Mehrnoosh | Rahim, Fakher | Shirbandi, Kiarash | Akbari, Rasoul
The aim of this review was to investigate the effects of possible harmful waves from either cell phone use or being within the range of the cell phone from 450 to 3800 MHz on the thyroid cells and hormones. Eight electronic datasets were systematically searched using MeSH terms, including “cell phone,” “mobile phone,” “GSM,” “radio frequency,” “smartphone,” “triiodothyronine,” “thyroxin,” “thyroid-stimulating hormone,” “T3,” “T4,” “TSH,” and “morphological” and all possible combinations, to identify relevant studies published up to Dec 2018. We also manually searched the reference lists of potentially selected studies to identify further relevant publications. About 161 relevant studies were initially found. After screening titles and abstracts, 139 studies were excluded, and finally 22 studies (comprising 7182 cases) were included in the qualitative synthesis. Of the 22 included studies, 11 studies reported changes in T3 and T4 levels (six reported a decrease in T3 levels and one reported increase in it); moreover, five found decreased T4 levels and two studies an increased level. In other 10 studies, TSH alteration was reported. Of these, two studies reported a decrease in TSH level and one reported an increase in the hormone levels, while in the remaining studies non-significant changes were reported. Finally, seven studies examined histological changes in the thyroid gland follicles and showed that the volume of these cells was reduced. Based on the evidence discussed above, the reduction in diameter of thyroid follicles is potentially linked with cell phone radiation. Exposure may negatively influence the iodine uptake in the thyroid gland or increases temperature effect on the thyroid gland. However, further research are needed in order to show that the level of TSH and thyroid hormone suppression by microwave.
Show more [+] Less [-]Does tourism investment improve the energy efficiency in transportation and residential sectors? Evidence from the OECD economies
2019
Li, Haiping | Gözgor, Giray | Lau, Chi Keung Marco | Paramati, Sudharshan Reddy
This paper investigates the impact of tourism investments on energy efficiency across the transportation and residential sectors of 32 Organization for Economic Co-operation and Development economies. Using annual data from 1995 to 2012, we employ various panel econometric techniques to achieve the study objectives. Given the nature of variables, the paper applies panel autoregressive distributed lag models to estimate the long-run elasticities of energy intensity. The long-run estimates confirm that tourism investments play an essential role in improving energy efficiency across the transportation and residential sectors. Furthermore, the results show that both the foreign direct investment inflows and trade openness also play a considerable role in reducing energy uses across these sectors. Finally, the findings suggest that the tourism investments Granger cause energy efficiency of transportation and residential sectors in the short-run. Given these findings, the paper adds considerable value to the empirical literature and also provides various policy- and practical implications.
Show more [+] Less [-]Arsenate removal from aqueous solutions by cuttlebone/copper oxide nanobiocomposite
2019
Momeni, Safieh | Ahmadi, Raheleh | Nabipour, Iraj
This study aims to illustrate the preparation of a new nanobiocomposite by incorporating copper oxide nanoparticles into cuttlebone matrix (CB/CuO NPs), and it was tested to define how effective it was to adsorb and remove arsenate from aqueous systems. CB is the bone tissue of cuttlefish with high porosity, permeability, and low cost. CuO NPs have been introduced as an effective arsenate adsorbent. Producing nanocomposite by introducing of CuO NPs in the structure of CB enhanced their stability and facilitated their separation from solution. Incorporation of CuO NPs in the structure of CB enhanced the adsorption capacity of CB. The adsorption data were fitted with both Langmuir and Freundlich isotherms, but Langmuir isotherm exhibited better matching rather than Freundlich isotherm. The maximum adsorption capacity (qₘₐₓ) was calculated from Langmuir adsorption isotherm which was around 25.13 mg g⁻¹. Kinetic data fitted well to the pseudo-second-order reaction model. The results indicate that the possible mechanism of arsenate adsorption on CB/CuO is through development of inner sphere complex. Simple preparation and abundant and good adsorption capacity in the presence of calcium ions indicate that the CB/CuO is suitable for removal of arsenate from contaminated drinking water.
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