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Cognitive function among schoolchildren in Lebanon: association with maternal alcohol drinking and smoking during pregnancy and domestic use of detergents and pesticides during childhood Полный текст
2019
Hallit, Souheil | Haddad, Chadia | Zeidan, Rouba Karen | Obeid, Sahar | Kheir, Nelly | Khatchadourian, Talar | Salameh, Pascale
To evaluate the relation between caregiver exposure to toxics during pregnancy and childhood and the child’s cognitive function in Lebanese children. This was a cross-sectional study conducted on Lebanese students in public and private schools from November 2017 to May 2018, enrolling 464 children. A first linear regression, taking the Cattell total score as the dependent variable and taking sociodemographic characteristics and the family history of the child as independent variables, showed that higher age (Beta = 1.65) was significantly associated with higher cognition, whereas a history of eczema in any of the parents (Beta = −7.32) was significantly associated with lower cognition in the child. A second linear regression, taking the Cattell total score as the dependent variable and taking sociodemographic characteristics and the family history of the child, and the exposure to toxics as independent variables, showed that maternal alcohol intake during pregnancy (Beta = −1.07) and detergent mixing (Beta = −1.48) were significantly associated with lower cognition in the child. A third linear regression, taking the Cattell total score as the dependent variable and taking sociodemographic characteristics and the family history of the child, the exposure to toxics and the diseases in the child as independent variables, showed that maternal alcohol intake during pregnancy (Beta = −1.07) and detergent mixing (Beta = −1.45) were significantly associated with lower cognition in the child, whereas a history of eczema in the child before the age of 2 years (Beta = 8.72) was significantly associated with higher cognition in the child. This study is the first to examine the association of a child’s prenatal exposure and their exposure during childhood to environmental toxicants with their cognitive function in Lebanon. We consider this study to be important as it shows the possible effect of cleaning products mixing and maternal alcohol consumption on cognitive functions among children in Lebanon.
Показать больше [+] Меньше [-]Variations in dissolved inorganic carbon species in effluents from large-scale municipal wastewater treatment plants (Qingdao, China) and their potential impacts on coastal acidification Полный текст
2019
Liu, Xiang-Yu | Yang, Xu-Feng | Li, Yun-Xiao | Zang, Han | Zhang, Long-Jun
With rapid development of global wastewater treatment plants (WWTPs), acidification and enhanced CO₂ release in receiving waters caused by high-CO₂ treated wastewater input have raised concerns. Insights into the variations in dissolved inorganic carbon (DIC) species in treated wastewater contribute to understanding the mechanisms of the acidification process. Here, we investigated three large-scale municipal WWTPs that discharged into the coast of Qingdao, China, for variations in effluent DIC species and their control mechanisms. The results showed that the effluent DIC concentrations, with a range of 2554–5718 μmol/L, significantly exceeded the concentration in seawater and mainly increased from winter to spring and decreased from summer to autumn. The effluent DIC and its δ¹³CDIC showed a good negative correlation. The ratios of effluent DIC to total alkalinity (DIC/TAlk) ranged from 1.00 to 1.24, and the proportions of CO₂ in DIC ranged from 0.9 to 19.7%; both sets of values significantly exceeded those in seawater. The proportions of CO₃²⁻ in DIC were only ~ 0.4%. These features determined that the CO₂ concentrations in effluents fluctuated from 3 to 80 times the concentration in seawater, whereas the CO₃²⁻ concentrations were less than 1/15 of those in seawater. Organic matter degradation and nitrogen removal processes made important contributions to the high effluent CO₂ concentrations. The increase in solubility induced by decreased temperature may be the main cause for the higher effluent CO₂ concentrations during winter as well as spring months with low effluent temperatures. Correspondingly, the effluent pH values were significantly lower than the seawater pH values and showed a good negative logarithmic correlation with the DIC/TAlk values, reflecting the control of DIC species on the pH values in treated wastewater. Variations in DIC species in treated wastewater can cause changes in the affected region and the degree of the induced acidification in receiving waters.
Показать больше [+] Меньше [-]Carbon emission intensity of electricity generation in Belt and Road Initiative countries: a benchmarking analysis Полный текст
2019
Zhang, Xingping | Zhang, Haonan | Zhao, Changhong | Yuan, Jiahai
The scope of this study is to analyze the carbon emissions intensity of electricity generation in “Belt and Road Initiative” (BRI) countries. The total CO₂ emissions from electricity generation in BRI nations increases from 4232.34 Mt in 2013 to 4402.38 Mt in 2015, accounting for 34.45% of global CO₂ emissions from electricity generation. Logarithmic mean Divisia index methodology is applied to analyze the drivers of carbon emissions intensity in BRI nations. The decomposition results revealed that the regional carbon emissions intensity in BRI nations increases during 2013–2015 and the power generation efficiency is the essential factor to improve carbon emissions performance in BRI developing countries. For BRI developing countries, promoting clean and efficient thermal power is a pragmatic priority for green power development.
Показать больше [+] Меньше [-]Effect of electrolytes on the simultaneous electrochemical oxidation of sulfamethoxazole, propranolol and carbamazepine: behaviors, by-products and acute toxicity Полный текст
2019
García-Espinoza, Josué Daniel | Mijaylova Nacheva, Petia
In this work, the effect of supporting electrolytes on the simultaneous electrochemical oxidation of the pharmaceuticals sulfamethoxazole (SMX), propranolol (PRO), and carbamazepine (CBZ) in aqueous solutions has been studied. Based on the identified by-products, the degradation mechanisms were proposed and the acute toxicity was evaluated for each electrolyte. Assays were carried out in batch mode in a 2 L undivided reactor using a niobium coated with boron-doped diamond (Nb/BDD) mesh anode and Ti cathode at 2.5 A in presence of different supporting electrolytes (Na₂SO₄, NaCl, or NaBr) at the same concentration of 7 mM. The degradation rates were higher in the assays with NaCl and NaBr. Reaction by-products were identified by gas chromatography–mass spectrometry. Indirect oxidation by electrogenerated reactive halogen species (RHS) was the main mechanism when halide ions were used as electrolytes. Ten by-products were detected using Na₂SO₄ as electrolyte, while 19 (12 non-halogenated and 7 halogenated) and 20 (10 non-halogenated and 10 halogenated) using NaCl and NaBr respectively. The proposed degradation pathways involve transformation (hydroxylation, deamination, desulfonation, and halogenation) and bond rupture to produce less molecular weight compounds and their further transformation until total degradation. Chlorinated and brominated by-products confirm halogenation reactions. The electrogenerated RHS presented a significant inhibition effect on Vibrio fischeri; nevertheless, acute toxicity was not presented using Na₂SO₄ as electrolyte and a pharmaceutical concentration of 5 μg/L. In this view, the role of the supporting electrolyte in electrochemical oxidation process is crucial since it strongly influence degradation rate, by-products, and acute toxicity.
Показать больше [+] Меньше [-]Gallic acid degradation by electron beam irradiation under various conditions Полный текст
2019
Alkhuraiji, Turki S. | Boukari, Sahidou O. B. | Leitner, Nathalie Karpel Vel
In this study, aqueous solutions of gallic acid (GA) were irradiated in an electron beam (EB) accelerator under different experimental conditions (various initial GA concentrations, presence or absence of oxidant and oxygen). For an initial GA concentration of 50 μM, complete GA degradation was achieved with an absorbed dose of 850 Gy in the presence of dissolved oxygen. Both GA removal and mineralization are favored when oxygen is present. The addition of persulfate anions (S₂O₈²⁻) or hydrogen peroxide (H₂O₂) also increased the efficiency of GA degradation and mineralization. For an absorbed dose of 14 kGy, GA mineralization reached approximately 45%, 55%, and 72% for the EB, EB/H₂O₂, and EB/S₂O₈²⁻systems, respectively. Three transformation products were tentatively identified in the presence of oxygen, these are the result of hydroxylation and ring opening reactions. No specific transformation product was found for the sulfate radical anion (SO₄–●) reaction. Four additional compounds, including a dimer, were identified in oxygen-free solutions. These findings demonstrate that water radiolysis based on EB irradiation is an efficient process to activate H₂O₂ and S₂O₈²⁻ anions and is an advanced oxidation process (AOP).
Показать больше [+] Меньше [-]The nephroprotective effects of allicin and ascorbic acid against cisplatin-induced toxicity in rats Полный текст
2019
Abdel-Daim, Mohamed M. | Abushouk, Abdelrahman Ibrahim | Donia, Thoria | Alarifi, Saud | Alkahtani, Saad | Aleya, Lotfi | Bungau, Simona G.
Cisplatin (CDDP) may induce nephrotoxicity through oxidative stress, DNA damage, and inflammation. This study was performed to evaluate the antioxidant and anti-inflammatory effects of allicin and ascorbic acid (AA) and investigate the nephroprotective efficacy of their combination against CDDP-induced intoxication. Rats were divided into seven groups: control, allicin (10 mg/kg for 14 days), AA (20 mg/kg for 14 days), CDDP (7 mg/kg as a single dose on the seventh experimental day), CDDP-allicin, CDDP-AA, and CDDP-allicin-AA (at the aforementioned doses). The administration of CDDP induced marked body weight loss and renal damage, manifested by significant increases (p < 0.05) in serum creatinine, urea, and uric acid levels and significant reductions in serum Na, Ca, and phosphorus concentrations, in addition to severe alterations in serum and renal tissue levels of tumor necrosis factor-α in comparison with control rats. Moreover, CDDP-intoxicated rats exhibited significantly (p < 0.05) higher lipid peroxidation, as well as lower levels of reduced glutathione and activities of glutathione peroxidase, superoxide dismutase, and catalase enzymes in the renal tissue, compared with control rats. The administration of allicin or AA significantly reduced (p < 0.05) the CDDP-induced changes in all the aforementioned parameters. Interestingly, allicin achieved comparable nephroprotection to AA in most assessed parameters; however, the restoration of normal serum and renal tissue concentrations of these parameters was more frequent in the CDDP-AA group. In conclusion, both allicin and AA showed significant nephroprotective effects against CDDP intoxication and their combination exhibited better protection than either agent alone. These results are probably mediated by their antioxidant and anti-inflammatory activities.
Показать больше [+] Меньше [-]Photosynthetic behaviors in response to intertidal zone and algal mat density in Ulva lactuca (Chlorophyta) along the coast of Nan’ao Island, Shantou, China Полный текст
2019
Jiang, Heng | Gong, Jingyu | Lou, Wenyong | Zou, Dinghui
Intertidal macroalgae suffer different environmental conditions and mat densities during growing period. In the present study, Ulva lactuca Linnaeus were collected from high, intermediate, and low tidal zones at Nan’ao Island, China. These algal photosynthetic pigments and photosynthesis behaviors with different mat densities were measured. The aim is to examine how the physiological responses and acclimation match the representative tidal distribution and algal mat density. The photosynthetic pigment (chlorophyll a and carotenoid) contents and irradiance-saturated maximum photosynthetic rates (Pₘₐₓ) were greater in low zone–grown U. lactuca compared with the algae grown at high and intermediate zones. Under low algal mat density, the Pₘₐₓ, apparent photosynthetic efficiency (α), and dark respiration rate (Rd) of U. lactuca grown at low zone were increased, whereas the irradiance saturation points (Iₖ) were decreased, compared with the algae grown at higher zone. However, the Pₘₐₓ of high and intermediate zone–grown U. lactuca at high algal mat density were greater than at low density. Moreover, the pH compensation point of low zone–grown thalli (9.98) was lower than the higher zone–grown thalli (more than 10.15); however, the chlorophyll fluorescence parameters (reflect photosynthetic system activity) of the thalli collected from the three different zones were similar. Therefore, we proposed that the effects of varied densities on the photosynthetic rates of these three tidal zone–grown U. lactuca thalli were different, which might be related with different capacity of HCO₃⁻ utilization of macroalgae at their zonations.
Показать больше [+] Меньше [-]Impact of energy consumption and human activities on carbon emissions in Pakistan: application of STIRPAT model Полный текст
2019
Anser, Muhammad Khalid
This study examines the impact of fossil fuel consumption, nonrenewable energy consumption, population, affluence, and poverty on carbon emissions in Pakistan by using a time series data from 1972 to 2014. The study uses a flexible ecological framework known as the STIRPAT model. The Auto Regressive Distributive Lag (ARDL) Model and Error Correction Model (ECM) are used to estimate the robust results. The results show that consumption of fossil fuels, population growth, improvement in affluence level, and urbanization are contributing factors to high carbon emissions in Pakistan. The results also highlight that poverty alleviation and carbon emissions have opposite trends, this shows that the efforts to reduce poverty are stimulating the consumption of low-cost energy sources such as fossil fuels, and contributing to carbon emissions. However, results indicate that an increase in the share of renewable energy in total energy use and consumption of hydroelectric energy has the potential to reduce carbon emissions in Pakistan. The results highlight that there is a need to promote the use of renewable and hydroelectric energy. At domestic level, this will assist to meet the energy demand of the growing population and also prove helpful to reduce carbon emissions. Thus, the study recommends that a transition from fossil fuel energy to renewable and hydroelectric energy could prove an effective strategy to improve the affluence level, to alleviate poverty and effective to reduce carbon emissions in Pakistan.
Показать больше [+] Меньше [-]Using nitrogen and oxygen isotopes to access sources and transformations of nitrogen in the Qinhe Basin, North China Полный текст
2019
Qin, Yong | Zhang, Dong | Wang, Fushun
Nitrate pollution in water is a common environmental problem worldwide. The Qinhe Basin (QHB) faces with the risk of eutrophication. To clarify nitrate pollution of river water, water chemical data, water isotope values (δD and δ¹⁸O–H₂O), and dual nitrate isotope values (δ¹⁵N–NO₃⁻ and δ¹⁸O–NO₃⁻) were used to discern sources and transformation mechanisms of nitrogen in the QHB. The nitrate concentrations of river water ranged from 0.71 to 20.81 mg L⁻¹. The δD and δ¹⁸O–H₂O values of river water varied from − 74 to −52‰ and from − 10.8 to − 7.2‰, with an average value of − 60‰ and − 8.2‰, respectively. The δ¹⁵N–NO₃⁻ and δ¹⁸O–NO₃⁻ values of nitrate ranged from − 6.7 to + 14.8‰ and from − 6.0 to + 5.6‰, with a mean value of + 4.6‰ and − 0.6‰, respectively. Assimilation by algae and the mixing of soil nitrogen, chemical fertilizer, sewage, and industrial wastewater could account for increasing δ¹⁵N–NO₃⁻ values. There was neither significantly positive nor negative correlation between δ¹⁵N–NO₃⁻ and δ¹⁸O–NO₃⁻ in river water, indicating that no obvious denitrification shifted isotopic values of nitrate in the QHB. Based on the dual isotopic values of nitrate and land use change in the watershed, it could be concluded that intensive nitrification dominated in the QHB, and dissolved nitrate was mainly derived from nitrification of ammonium in fertilizer, soil nitrogen, and domestic sewage. As the primary nitrate sources identified in the QHB, effective fertilization and afforestation can be taken to protect water resource from nitrate pollution.
Показать больше [+] Меньше [-]Pb2+ adsorption by a compost obtained from the treatment of tobacco from smuggled cigarettes and industrial sewage sludge Полный текст
2019
Seremeta, Daniele Cristina Hass | da Silva, Cleber Pinto | Zittel, Rosimara | de Campos, Sandro Xavier
The adsorption of Pb²⁺ by a compost obtained from the treatment of tobacco from smuggled cigarettes (SCT) and industrial sewage sludge (ISS) was investigated. The Pb²⁺ adsorption process was evaluated as function of different concentrations of adsorbent and adsorbate, pH variations, and contact time. Fourier transformed infrared spectroscopy (FTIR) and energy dispersive X-ray spectrometry (EDX) were adopted to obtain information regarding structural changes and a better understanding of the adsorption mechanism. The adsorbent maximum adsorption capacity for Pb²⁺, calculated using the Sips equation, was 21.454 mg/g with 3 g/L adsorbent at pH 5. The adsorption kinetics best adjustment was obtained using the pseudo-second-order model with a time of 240 min to reach the adsorption equilibrium. FTIR and EDX results suggest that Pb²⁺ might have bonded to phenolic, carboxylic, hydroxyl, and amine groups; they also show formation of organometallic complexes and cationic exchange between the compost and the solution. The study confirmed that the compost evaluated can be used as a potential adsorbent in environments contaminated with Pb²⁺.
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