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Occurrence of organotin compounds in river sediments under the dynamic water level conditions in the Three Gorges Reservoir Area, China
2015
Gao, Jun-Min | Zhang, Ke | Chen, You-Peng | Guo, Jin-Song | Wei, Yun-Mei | Jiang, Wen-Chao | Zhou, Bin | Qiu, Hui
The Three Gorges Project is the largest hydro project in the world, and the water level of the Three Gorges Reservoir (TGR) is dynamic and adjustable with the aim of flood control and electrical power generation. It is necessary to investigate the pollutants and their underlying contamination processes under dynamic water levels to determine their environmental behaviors in the Three Gorges Reservoir Area (TGRA). Here, we report the assessment of organotin compounds (OTs) pollution in the river sediments of the TGRA. Surface sediment samples were collected in the TGRA at low and high water levels. Tributyltin (TBT), triphenyltin (TPhT), and their degradation products in sediments were quantified by gas chromatography-mass spectrometry. Butyltins (BTs) and phenyltins (PhTs) were detected in sediments, and BTs predominated over PhTs in the whole study area under dynamic water level conditions. The concentrations of OTs in sediments varied markedly among locations, and significant concentrations were found in river areas with high levels of boat traffic and wastewater discharge. Sediments at all stations except Cuntan were lightly contaminated with TBT, and total organic carbon (TOC) was a significant factor affecting the fate of TBT in the TGRA. The butyltin and phenyltin degradation indices showed no recent inputs of TBT or TPhT into this region, with the exception of fresh TPhT input at Xiakou Town. Shipping activity, wastewater discharge, and agriculture are the most likely sources of OTs in the TGRA.
Afficher plus [+] Moins [-]Assessment of hematological profiles of adult male athletes from two different air pollutant zones of West Bengal, India
2015
Das, Paulomi | Chatterjee, Pinaki
Health effects from air pollution are severe concern of today’s world. The study was undertaken to assess the effects of air pollution on hematological profiles of trained and untrained males of West Bengal. The sample consisted of 60 sprinters, 60 footballers, and 120 untrained males, subdivided into two groups from two zones, namely, Tollygunge and Sonarpur. Suspended particulate matter (SPM), respirable particulate matter (RPM), oxides of sulfur (SOₓ), and oxides of nitrogen (NOₓ) of ambient air were monitored for both zones. Height and weight of all the subjects were measured. Venous blood sample was drawn from the cubital vein, and the red blood cell count (TC), packed cell volume (PCV), hemoglobin (Hb) concentration, mean corpuscular volume (MCV), and mean corpuscular hemoglobin concentration (MCHC) were determined by standard methods. Results revealed that SPM, RPM, SOₓ, and NOₓ concentrations were significantly higher in the Tollygunge area than Sonarpur. TC, PCV, and Hb concentration of untrained males were significantly higher than footballers in both regions but no significant difference were observed when compared with sprinters, except the Hb concentration in the Tollygunge zone. On the other hand, all hematological parameters of both trained and untrained males were significantly higher in the Sonarpur area than Tollygunge. It was concluded that environmental air pollutants might influence hematological profile adversely both in trained and sedentary males. However, further investigation in this area is needed.
Afficher plus [+] Moins [-]Life cycle analysis of management options for organic waste collected in an urban area
2015
Di Maria, Francesco | Micale, Caterina
Different options for managing the organic fraction (OF) of municipal solid waste generated in a given urban area were analyzed by life cycle assessment (LCA) for different source segregation (SS) intensities ranging from 0 to 52 %. The best management option for processing the OF remaining in the residual organic fraction (ROF) for the different SS intensities was by incineration. Landfilling and mechanical biological treatment (MBT) of ROF gave higher impacts. Aerobic treatment alone or combined with anaerobic digestion (AD) for processing the source-segregated organic fraction (SSOF) led to relevant environmental impact reduction even if the difference between the two options was quite negligible. The weighted impact showed that scenarios using incineration always gave environmental gains, whereas there was a higher environmental burden with the scenarios using MBT.
Afficher plus [+] Moins [-]Leaching behaviour and environmental risk assessment of heavy metals from electronic solder in acidified soil
2015
Lao, Xiaodong | Cheng, Congqian | Min, Xiaohua | Zhao, Jie | Zhou, Dayu | Li, Xiaogang
The leaching behaviour of Sn and Pb elements from eutectic SnPb solder of electronic waste in acidic soil was investigated through acidification with HCl–H₂SO₄ solution and compared with saline solution. The amounts of Sn and Pb elements leached, when subjected to acidic soil, are higher than those with saline soil. Evidence for the significantly preferential release of Sn into the leachate is provided; the galvanic couple accelerated such preferential release. Surface product analysis reveals the slight damage of SnPb in saline soil. Serious dissolution due to electrochemical reaction and a thick, porous PbSO₄ surface layer are observed in acidified soil, suggesting more severe toxicity potential of Pb in soil rather than in water.
Afficher plus [+] Moins [-]Effects of bisphenol A on chlorophyll fluorescence in five plants
2015
Zhang, Jiazhi | Wang, Lihong | Li, Man | Jiao, Liya | Zhou, Qing | Huang, Xiaohua
The aim of this study was to evaluate the effects of bisphenol A (BPA) on plant photosynthesis and determine whether the photosynthetic response to BPA exposure varies in different plants. Chlorophyll fluorescence techniques were used to investigate the effects of BPA on chlorophyll fluorescence parameters in tomato (Lycopersicum esculentum), lettuce (Lactuca sativa), soybean (Glycine max), maize (Zea mays), and rice (Oryza sativa) seedlings. Low-dose (1.5 or 3.0 mg L⁻¹) BPA exposure improved photosystem II efficiency, increased the absorption and conversion efficiency of primary light energy, and accelerated photosynthetic electron transport in each plant, all of which increased photosynthesis. These effects weakened or disappeared after the withdrawal of BPA. High-dose (10.0 mg L⁻¹) BPA exposure damaged the photosystem II reaction center, inhibited the photochemical reaction, and caused excess energy to be released as heat. These effects were more evident after the highest BPA dose (17.2 mg L⁻¹), but they weakened after the withdrawal of BPA. The magnitude of BPA exposure effects on the chlorophyll fluorescence parameters in the five plants followed the order: lettuce > tomato > soybean > maize > rice. The opposite order was observed following the removal of BPA. In conclusion, the chlorophyll fluorescence response in plants exposed to BPA depended on BPA dose and plant species.
Afficher plus [+] Moins [-]Physiological and biochemical response of soil-grown barley (Hordeum vulgare L.) to cerium oxide nanoparticles
2015
Rico, Cyren M. | Barrios, Ana C. | Tan, Wenjuan | Rubenecia, Rosnah | Lee, Sang-Chul | Varela-Ramirez, Armando | Peralta-Videa, Jose R. | Gardea-Torresdey, Jorge L.
A soil microcosm study was performed to examine the impacts of cerium oxide nanoparticles (nCeO₂) on the physiology, productivity, and macromolecular composition of barley (Hordeum vulgare L.). The plants were cultivated in soil treated with nCeO₂ at 0, 125, 250, and 500 mg kg⁻¹ (control, nCeO₂-L, nCeO₂-M, and nCeO₂-H, respectively). Accumulation of Ce in leaves/grains and its effects on plant stress and nutrient loading were analyzed. The data revealed that nCeO₂-H promoted plant development resulting in 331 % increase in shoot biomass compared with the control. nCeO₂ treatment modified the stress levels in leaves without apparent signs of toxicity. However, plants exposed to nCeO₂-H treatment did not form grains. Compared with control, nCeO₂-M enhanced grain Ce accumulation by as much as 294 % which was accompanied by remarkable increases in P, K, Ca, Mg, S, Fe, Zn, Cu, and Al. Likewise, nCeO₂-M enhanced the methionine, aspartic acid, threonine, tyrosine, arginine, and linolenic acid contents in the grains by up to 617, 31, 58, 141, 378, and 2.47 % respectively, compared with the rest of the treatments. The findings illustrate the beneficial and harmful effects of nanoceria in barley.
Afficher plus [+] Moins [-]Influence of effluent organic matter on copper speciation and bioavailability in rivers under strong urban pressure
2015
Matar, Z. | Soares Pereira, C. | Chebbo, G. | Uher, E. | Troupel, M. | Boudahmane, L. | Saad, M. | Gourlay-France, C. | Rocher, V. | Varrault, Gilles
This study focuses on spatiotemporal variations in the type of dissolved organic matter (DOM) and copper binding ability both upstream and downstream of Paris. It also compares the relative influence of both natural DOM upstream of Paris and effluent dissolved organic matter (EfDOM) output from a wastewater treatment plant (WWTP) on trace metal speciation and bioavailability in aquatic systems. In addition to the typical high- and low-affinity binding sites, a third family of very high-affinity binding sites has been highlighted for EfDOM. In receiving waters downstream of Paris during low-flow periods, the percentage of high- and very high-affinity sites originating from EfDOM reaches nearly 60 %. According to the speciation computation, the free copper concentration upstream of Paris exceeds the downstream Paris concentration by a factor of 2 to 4. As regards copper bioavailability, the highest EC50ₜₒₜ values were observed for EfDOM and downstream DOM, with a very low aromaticity and low UV absorbance. This finding suggests that specific ultraviolet absorbance (SUVA) is unlikely to be useful in assessing metal speciation and toxicity in aquatic systems subject to strong urban pressures. These results also highlight that the copper speciation computation for surface water exposed to considerable human pressures should include not only the humic and/or fulvic part of dissolved organic carbon but more hydrophilic fractions as well, originating for example from EfDOM.
Afficher plus [+] Moins [-]A margin of exposure approach to assessment of non-cancerous risk of diethyl phthalate based on human exposure from bottled water consumption
2015
Zare Jeddi, Maryam | Rastkari, Noushin | Ahmadkhaniha, Reza | Yunesian, Masud | Nabizadeh, Ramin | Daryabeygi, Reza
Phthalates may be present in food due to their widespread presence as environmental contaminants or due to migration from food contact materials. Exposure to phthalates is considered to be potentially harmful to human health as well. Therefore, determining the main source of exposure is an important issue. So, the purpose of this study was (1) to measure the release of diethyl phthalate (DEP) in bottled water consumed in common storage conditions specially low temperature and freezing conditions; (2) to evaluate the intake of DEP from polyethylene terephthalate (PET) bottled water and health risk assessment; and (3) to assess the contribution of the bottled water to the DEP intake against the tolerable daily intake (TDI) values. DEP migration was investigated in six brands of PET-bottled water under different storage conditions room temperature, refrigerator temperature, freezing conditions (40 °C ,0 °C and −18 °C) and outdoor] at various time intervals by magnetic solid extraction (MSPE) using gas chromatography–mass spectroscopy (GC-MS). Eventually, a health risk assessment was conducted and the margin of exposure (MOE) was calculated. The results indicate that contact time with packaging and storage temperatures caused DEP to be released into water from PET bottles. But, when comprising the DEP concentration with initial level, the results demonstrated that the release of phthalates were not substantial in all storage conditions especially at low temperatures (<25 °C) and freezing conditions. The daily intake of DEP from bottled water was much lower than the reference value. However, the lowest MOE was estimated for high water consumers (preschooler > children > lactating women > teenagers > adults > pregnant women), but in all target groups, the MOE was much higher than 1000, thus, low risk is implied. Consequently, PET-bottled water is not a major source of human exposure to DEP and from this perspective is safe for consumption.
Afficher plus [+] Moins [-]Stable isotope probing reveals the importance of Comamonas and Pseudomonadaceae in RDX degradation in samples from a Navy detonation site
2015
Jayamani, Indumathy | Cupples, Alison M.
This study investigated the microorganisms involved in hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) degradation from a detonation area at a Navy base. Using Illumina sequencing, microbial communities were compared between the initial sample, samples following RDX degradation, and controls not amended with RDX to determine which phylotypes increased in abundance following RDX degradation. The effect of glucose on these communities was also examined. In addition, stable isotope probing (SIP) using labeled (¹³C₃, ¹⁵N₃-ring) RDX was performed. Illumina sequencing revealed that several phylotypes were more abundant following RDX degradation compared to the initial soil and the no-RDX controls. For the glucose-amended samples, this trend was strong for an unclassified Pseudomonadaceae phylotype and for Comamonas. Without glucose, Acinetobacter exhibited the greatest increase following RDX degradation compared to the initial soil and no-RDX controls. Rhodococcus, a known RDX degrader, also increased in abundance following RDX degradation. For the SIP study, unclassified Pseudomonadaceae was the most abundant phylotype in the heavy fractions in both the presence and absence of glucose. In the glucose-amended heavy fractions, the 16S ribosomal RNA (rRNA) genes of Comamonas and Anaeromxyobacter were also present. Without glucose, the heavy fractions also contained the 16S rRNA genes of Azohydromonas and Rhodococcus. However, all four phylotypes were present at a much lower level compared to unclassified Pseudomonadaceae. Overall, these data indicate that unclassified Pseudomonadaceae was primarily responsible for label uptake in both treatments. This study indicates, for the first time, the importance of Comamonas for RDX removal.
Afficher plus [+] Moins [-]pH and ionic strength effects on the binding constant between a nitrogen-containing polycyclic aromatic compound and humic acid
2015
Zhang, Guizhen | Lee, Chon-Lin | Hsieh, Ping-Chieh | Brimblecombe, Peter | Gao, Shumin
Polycyclic aromatic compounds (PACs) are widespread environmental pollutants with a high potential to act as human carcinogens and mutagens. The behavior of PACs is significantly affected by their interactions with dissolved organic matter (DOM), such as their transport, solubility, bioavailability, and bioaccumulation in the aquatic environment. Being a basic PAC, benzo(h)quinoline (BQ) is the dominant species, as the solution’s pH value is higher than BQ’s pK ₐ (pK ₐ of BQ = 4.2). In contrast, benzo(h)quinolinium (BQH⁺) is the major species, as the solution’s pH value is lower than its pK ₐ. The binding constant (K DOC), measured by fluorescence quenching, between BQ/BQH⁺ and Leonardite humic acid (LHA) would decrease 70 to 95 % and 20 to 90 % when increasing the ionic strength in acidic and neutral to basic conditions, respectively. The results can be attributed to the added cation (Na⁺ and Mg²⁺), which forms a bridge with LHA and enhances the intramolecular reaction among these functional groups, therefore inducing the coiling up within the LHA molecule. In addition, the decrease of the K DOC with added MgCl₂/MgSO₄ (75–95 %) is higher than that with added NaCl/Na₂SO₄ (20–75 %), indicating that the K DOC was affected by the charge density of cations. The fluorescence intensity of BQH⁺ in the absence of LHA (F ₀) was found to decay only in the acidic solution with Cl⁻, suggesting that Cl⁻ might be a heavy atom serving as a quencher in an acidic solution.
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