Уточнить поиск
Результаты 2281-2290 из 4,042
The Impact of Climate, Sulfur Dioxide, and Industrial Dust on δ18O and δ13C in Glucose from Pine Tree Rings Growing in an Industrialized Area in the Southern Part of Poland Полный текст
2016
Sensuła, Barbara M.
The mass spectrometric analysis of the impact of sulfur dioxide and dust emission on carbon and oxygen stable isotopic compositions of glucose hydrolysed from α-cellulose samples extracted from Scots pine growing in the vicinity of “Huta Katowice” steelworks was the main aim of this study. The annual rings covered the time span from 1975 to 2012 AD. The relationships between climatic conditions, sulfur dioxide, and industrial dust emission and oxygen and carbon isotopic compositions were analyzed using correlation function methods. This study shows the first analysis of carbon and oxygen stable isotopes in glucose as the bio-indicators of CO₂, sulfur dioxide, and industrial dust emission. The anticoincidence trend of δ¹⁸O and δ¹³C and dust and sulfur dioxide confirms that the decreases of dust and sulfur dioxide industrial emission increase δ¹⁸O and δ¹³C values in glucose.
Показать больше [+] Меньше [-]Characterization of river pollution at the watershed scale Полный текст
2016
Lesueur Jannoyer M. | Mottes C. | Clostre F. | Carles C. | Guene M. | Plet J. | Della Rossa P. | Bazizi A. | Cattan P.
Crisis management of chronic pollution: contaminated soil and human health Полный текст
2016
Lesueur Jannoyer M. (ed.) | Cattan P. (ed.) | Woignier T. (ed.) | Clostre F. (ed.)
Crisis Management of Chronic Pollution: Contaminated Soil and Human Health deals with a long term pollution problem, generated by the former use of organochlorine pesticides. Through a case study of the chlordecone pollution in the French West Indies, the authors illustrate a global and systemic mobilization of research institutions and public services. This "management model", together with its major results, the approach and lessons to be learned, could be useful to other situations. This book gathers all the works that have been carried out over the last ten years or more and links them to decision makers' actions and stakeholders' expectations. This reference fills a gap in the literature on chronic pollution. (Résumé d'auteur)
Показать больше [+] Меньше [-]Disruption of steroidogenesis after dimethoate exposure and efficacy of N-acetylcysteine in rats: an old drug with new approaches Полный текст
2016
Jallouli, Manel | El Bini Dhouib, Ines | Dhouib, Hanène | Lasram, Montassar | Gharbi, Najoua | El Fazaa, Saloua
Organophosphates (OPs) like dimethoate (DMT), are pesticides used worldwide, which can affect both animals and human. Whereas their toxicity is due to acetylcholinesterase inhibition, their secondary toxic effects have been related to free oxygen radical biosynthesis. The present study was designed to investigate the reprotoxic effects of DMT and the protective role of N-acetylcysteine (NAC) in male rat. DMT (20 mg/ kg/body weight) was administered daily to rats via gavage in corn oil and NAC (2 g/l) was added to drinking water for 30 days. Rats were sacrificed on the 30th day, 2 h after the last administration. Markers of testis injury (steroidogenesis impairment) and oxidative stress (lipid peroxidation, reduced glutathione, and antioxidant status) were assessed. In DMT-exposed rats, the serum level of testosterone was decreased. Further, a significant increase in lipid peroxidation level and a significant decrease in the activities of antioxidant enzymes were observed in the testis of rats during DMT intoxication. Real-time PCR (RT-PCR) analysis demonstrated a decrease in messenger RNA (mRNA) levels for testicular steroidogenic acute regulatory StAR protein, cytochrome P450scc, 3β-hydroxysteroid dehydrogenase (3β-HSD), and 17β hydroxysteroid dehydrogenase (17β-HSD) in the testis after DMT exposure. No significant changes in the oxidative stress status and selected reproductive variables were observed on CTN group, whereas NAC restored the oxidative stress and the steroidogenesis on NAC group. Dimethoate induces reprotoxicity and oxidative stress. N-acetylcysteine showed therapeutic recovery effects against dimethoate toxicity.
Показать больше [+] Меньше [-]Comparison of PAHs uptake by selected Monocotyledones and Dicotyledones from municipal and industrial sewage sludge Полный текст
2016
Gworek, Barbara | Klimczak, Katarzyna | Kijeńska, Marta | Gozdowski, Dariusz
The study was focused on two goals: (i) the confirmation of the existence of a general relation between the content of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge and in plants growing in it, regardless of the type and content of sewage sludge, and (ii) if so, the answer to the question whether the uptake of PAHs by plants depends on their type. To realize the set aims, the contents of PAHs in four differentiated plant species were measured, two belonging to the Monocotyledones and two belonging to Dicotyledones group, growing in municipal and industrial sewage sludge in two locations. All the investigations were carried out during the period of 3 years. The results clearly demonstrated that the uptake of PAHs by a plant depended on polyaromatic hydrocarbon concentration in the sewage sludge. The relation between accumulation coefficient of PAHs in plant material vs. the content of PAH in sewage sludge was of exponential character. The results indicate that in case of four- and five-ring PAHs, the root uptake mechanism from soil solution occurs, regardless of the type and origin of sewage sludge and the type of plant. For three-ring PAHs, we can assume for Monocotyledones that the root uptake mechanism occurs because we observe a significant correlation between the content of fluorene, phenanthrene, and anthracene in plant material and in the sewage sludge. For Dicotyledones, the correlation is insignificant, and in this case probably two mechanisms occur—the uptake by roots and by leaves.
Показать больше [+] Меньше [-]Predicting seasonal fate of phenanthrene in aquatic environment with a Markov chain Полный текст
2016
Sun, Caiyun | Ma, Qiyun | Zhang, Jiquan | Zhou, Mo | Chen, Yanan
Phenanthrene (Phe) with carcinogenicity is ubiquitous in the environment, especially in aquatic environment; its toxicity is greater. To help determine toxicity risk and remediation strategies, this study predicted seasonal fate of Phe in aquatic environment. Candidate mechanisms including biodegradation, sorption, desorption, photodegradation, hydrolysis and volatility were studied; the results for experiments under simulated conditions for normal, wet and dry seasons in the Yinma River Basin indicated that biodegradation in sediment, sorption, desorption, and volatility were important pathways for elimination of Phe from aquatic environment and showed seasonal variations. A microcosm which was used to mimic sediment/water system was set up to illustrate seasonal distribution and transport of Phe. A Markov chain was applied to predict seasonal fate of Phe in air/water/sediment environment, the predicted results were perfectly agreed with results of microcosm experiments. Predicted results with a Markov chain suggested that volatility and biodegradation in sediment were main elimination pathways, and contributions of elimination pathways showed seasonal variations; Phe was eliminated from water and sediment to negligible levels over around 250 h in August and over 1000 h in May; in November, Phe was eliminated from water to a negligible level while about 31 % of Phe amount still remained in sediment over 1000 h.
Показать больше [+] Меньше [-]Oxalate-assisted oxidative degradation of 4-chlorophenol in a bimetallic, zero-valent iron–aluminum/air/water system Полный текст
2016
Fan, Jinhong | Wang, Hongwu | Ma, Luming
The reaction of zero-valent iron and aluminum with oxygen produced reactive oxidants that can oxidize 4-chlorophenol (4-CP). However, oxidant yield without metal surface cleaning to dissolve the native oxide layer or in the absence of ligands was too low for practical applications. The addition of oxalate (ox) to dissolved oxygen-saturated solution of Fe⁰–Al⁰ significantly increased oxidant yield because of the dissolution, pH buffer, and complexing characteristics of ox. Ox-enhanced reactive oxidant generation was affected by ox concentration and solution pH. The critical effect of ox dosing was confirmed with the reactive species of [Feᴵᴵ(ox)₀] and [Feᴵᴵ(ox)₂ ²⁻]. Systematic studies on the effect of the initial and in situ solution pH revealed that 4-CP oxidation was controlled by the continuous release of dissolved Fe²⁺ and Al³⁺, their fate, and the activation mechanisms of O₂ reduction. The degradation pathway of 4-CP in ox-enhanced Fe⁰–Al⁰/O₂ may follow the 4-chlorocatechol pathway. The robustness of the ox-enhanced Al⁰–Fe⁰–O₂ process was determined with one-time dosing of ox. Therefore, ox is an ideal additive to enhancing the Fe⁰–Al⁰/O₂ system for the oxidative degradation of aqueous organic pollutants.
Показать больше [+] Меньше [-]On the causal links between health indicator, output, combustible renewables and waste consumption, rail transport, and CO2 emissions: the case of Tunisia Полный текст
2016
Ben Jebli, Mehdi
This study employs the autoregressive distributed lag (ARDL) approach and Granger causality test to investigate the short- and long-run relationships between health indicator, real GDP, combustible renewables and waste consumption, rail transport, and carbon dioxide (CO₂) emissions for the case of Tunisia, spanning the period of 1990–2011. The empirical findings suggest that the Fisher statistic of the Wald test confirm the existence of a long-run relationship between the variables. Moreover, the long-run estimated elasticities of the ARDL model provide that output and combustible renewables and waste consumption have a positive and statistically significant impact on health situation, while CO₂ emissions and rail transport both contribute to the decrease of health indicator. Granger causality results affirm that, in the short-run, there is a unidirectional causality running from real GDP to health, a unidirectional causality from health to combustible renewables and waste consumption, and a unidirectional causality from all variables to CO₂ emissions. In the long-run, all the computed error correction terms are significant and confirm the existence of long-run association among the variables. Our recommendations for the Tunisian policymakers are as follows: (i) exploiting wastes and renewable fuels can be a good strategy to eliminate pollution caused by emissions and subsequently improve health quality, (ii) the use of renewable energy as a main source for national rail transport is an effective strategy for public health, (iii) renewable energy investment projects are beneficial plans for the country as this contributes to the growth of its own economy and reduce energy dependence, and (iii) more renewable energy consumption leads not only to decrease pollution but also to stimulate health situation because of the increase of doctors and nurses numbers.
Показать больше [+] Меньше [-]Seafood consumption among Chinese coastal residents and health risk assessment of heavy metals in seafood Полный текст
2016
Zhao, Ran | Yan, Shuangshuang | Liu, Min | Wang, Bi | Hu, Dong | Guo, Dongbei | Wang, Juan | Xu, Wanting | Fan, Jun
The aims of the present study were to obtain the seafood dietary patterns of coastal residents, to determine the concentrations of heavy metals, and to evaluate the possible health risks caused by seafood intake. The daily food intakes of 24 types of seafood were collected from 738 participants from Xiamen, a southern Chinese coastal city, using food frequency questionnaire (FFQ) and dietary history method. One hundred and fifty-six samples of 14 types of highest intake seafood were collected from local markets for lead (Pb), cadmium (Cd), chromium (Cr), mercury (Hg), and arsenic (As) determination. Health risks via seafood consumption were evaluated by calculating the target hazard quotient (THQ) and the total hazard index (HI) for carcinogenic and non-carcinogenic effects recommended by the US Environmental Protection Agency. The results showed that the seafood daily intake of Xiamen residents was 61.5 (2.14, 115) g/day. The concentrations of Pb, Cd, Cr, Hg, and As in seafood were ND–0.45 mg/kg, ND–0.19 mg/kg, ND–0.80 mg/kg, ND–0.70 mg/kg, and 0.32–16.9 mg/kg, respectively. Concentrations of Cd and As in some samples were higher than national limitation standards. Consumption of 14 common types of seafood would not pose non-carcinogenic risk. However, some types, such as sparuslatus, oyster, and porphyra tenera, would form a carcinogenic risk. Regardless of a carcinogenic or non-carcinogenic risk, As posed the highest risk on humans. The observed HI value for non-carcinogenic effect of all metals in all seafood reached 0.69–2.20, and the metal orders of risk can be listed as As > Hg > Cr > Cd > Pb, reiterating the risk of As is a matter of concern in seafood from Xiamen markets.
Показать больше [+] Меньше [-]Speciation of potentially mobile Si in Yangtze Estuary surface sediments: estimates using a modified sequential extraction technique Полный текст
2016
Zhu, Huagang | Wang, Chao | Wang, Peifang | Hou, Jun | Qian, Jin | Ao, Yanhui | Liu, Cui
To improve our understanding of the Si-related biogeochemical processes that occur in estuarine ecosystems with large subaqueous deltas (e.g., the Yangtze Estuary; YE), the speciation of Si in the surface sediments of the YE was investigated. The relationships between the different Si species and sediment bulk parameters were also discussed. Based on modified sequential extraction method, we can successfully estimate the following five sedimentary potentially mobile Si pools: weak acid leachable Si (W-Si); Si bound to organic matter (H-Si); Si coprecipitated with amorphous Fe/Al oxides (O-Si); Si coprecipitated with crystalline Fe/Al oxides (Oᵤᵥ-Si), and biogenic silica (B-Si). The total potentially mobile Si pool (T-Si) ranged between 1689.31 and 5487.10 μg/g, with high values observed in deltaic mud deposits. The Si fractions were closely correlated with grain size compositions, except for O-Si. In deltaic mud deposits, efficient loss of organic matters and recycling of Fe oxides probably resulted in the amorphous or poorly crystalline Fe oxides uncoupled with the clay fractions, and thus leading to the lack of correlation between O-Si and grain size. As compared with Oᵤᵥ-Si, the O-Si should possess stronger mobility, which highlights the importance of quantifying the O-Si pool in deltaic sediments.
Показать больше [+] Меньше [-]