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Resultados 3111-3120 de 3,208
An appraisal of biological responses and network of environmental interactions in non-mining and mining impacted coastal waters Texto completo
2015
Fernandes, Christabelle E. G. | Malik, Ashish | Jineesh, V. K. | Fernandes, Sheryl O. | Das, Anindita | Pandey, Sunita S. | Kanolkar, Geeta | Sujith, P. P. | Velip, Dhillan M. | Shaikh, Shagufta | Helekar, Samita | Gonsalves, Maria Judith | Nair, Shanta | LokaBharathi, P. A.
The coastal waters of Goa and Ratnagiri lying on the West coast of India are influenced by terrestrial influx. However, Goa is influenced anthropogenically by iron-ore mining, while Ratnagiri is influenced by deposition of heavy minerals containing iron brought from the hinterlands. We hypothesize that there could be a shift in biological response along with changes in network of interactions between environmental and biological variables in these mining and non-mining impacted regions, lying 160 nmi apart. Biological and environmental parameters were analyzed during pre-monsoon season. Except silicates, the measured parameters were higher at Goa and related significantly, suggesting bacteria centric, detritus-driven region. At Ratnagiri, phytoplankton biomass related positively with silicate suggesting a region dominated by primary producers. This dominance perhaps got reflected as a higher tertiary yield. Thus, even though the regions are geographically proximate, the different biological response could be attributed to the differences in the web of interactions between the measured variables.
Mostrar más [+] Menos [-]Screening of 18 species for digestate phytodepuration Texto completo
2015
Pavan, Francesca | Breschigliaro, Simone | Borin, Maurizio
This experiment assesses the aptitude of 18 species in treating the digestate liquid fraction (DLF) in a floating wetland treatment system. The pilot system was created in NE Italy in 2010 and consists of a surface-flow system with 180 floating elements (Tech-IA®) vegetated with ten halophytes and eight other wetland species. The species were transplanted in July 2011 in basins filled with different proportions of DLF/water (DLF/w); periodic increasing of the DLF/w ratio was imposed after transplanting, reaching the worst conditions for plants in summer 2012 (highest EC value 7.3 mS cm/L and NH₄-N content 225 mg/L). It emerged that only Cynodon dactylon, Typha latifolia, Elytrigia atherica, Halimione portulacoides, Salicornia fruticosa, Artemisia caerulescens, Spartina maritima and Puccinellia palustris were able to survive under the system conditions. Halophytes showed higher dry matter production than other plants. The best root development (up to 40-cm depth) was recorded for Calamagrostis epigejos, Phragmites australis, T. latifolia and Juncus maritimus. The highest nitrogen (10–15 g/m²) and phosphorus (1–4 g/m²) uptakes were obtained with P. palustris, Iris pseudacorus and Aster tripolium. In conclusion, two halophytes, P. palustris and E. atherica, present the highest potential to be used to treat DLF in floating wetlands.
Mostrar más [+] Menos [-]Effects of ambient PM2.5 on pathological injury, inflammation, oxidative stress, metabolic enzyme activity, and expression of c-fos and c-jun in lungs of rats Texto completo
2015
Li, Ruijin | Kou, Xiaojing | Xie, Lizhi | Cheng, Fangqin | Geng, Hong
Fine particulate matter (PM₂.₅) exposure is associated with morbidity and mortality induced by respiratory diseases and increases the lung cancer risk. However, the mechanisms therein involved are not yet fully clarified. In this study, the PM₂.₅ suspensions at different dosages (0.375, 1.5, 6.0, and 24.0 mg/kg body weight) were respectively given to rats by the intratracheal instillation. The results showed that PM₂.₅ exposure induced inflammatory cell infiltration and hyperemia in the lung tissues and increased the inflammatory cell numbers in bronchoalveolar lavage fluid. Furthermore, PM₂.₅ significantly elevated the levels of pro-inflammatory mediators including tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1β, and intercellular adhesion molecule 1 (ICAM-1) and the expression of c-fos and c-jun in rat lungs exposed to higher dose of PM₂.₅. These changes were accompanied by decreases of activities of superoxide dismutase and increases of levels of malondialdehyde, inducible nitric oxide synthase, nitric oxide, cytochrome P450s, and glutathione S-transferase. The results implicated that acute exposure to PM₂.₅ induced pathologically pulmonary changes, unchained inflammatory and oxidative stress processes, activated metabolic enzyme activity, and enhanced proto-oncogene expression, which might be one of the possible mechanisms by which PM₂.₅ pollution induces lung injury and may be the important determinants for the susceptibility to respiratory diseases.
Mostrar más [+] Menos [-]Analytical, toxicological and kinetic investigation of decomposition of the drug diclofenac in waters and wastes using gamma radiation Texto completo
2015
Bojanowska-Czajka, A. | Kciuk, G. | Gumiela, M. | Borowiecka, S. | Nałęcz-Jawecki, G. | Koc, A. | Garcia-Reyes, J. F. | Ozbay, D Solpan | Trojanowicz, M.
The radiolytic decomposition of the drug diclofenac (DCF), and in limited extent, also two other widely used drugs, ibuprofen and carbamazepine, was examined using liquid chromatography (LC) methods. The efficiency of DCF decomposition was examined in function of the absorbed dose of gamma radiation, and also in the presence of selected scavengers of radicals, which are commonly present in natural waters and wastes. Three different tests were employed for the monitoring of toxicity changes in the irradiated DCF solutions. The LC/mass spectrometry (MS) was used for the determination of products of DCF radiolysis. Using pulse-radiolysis method with the spectrophotometric detection, the rate constant values were determined for reactions of DCF with the main products of water radiolysis: hydroxyl radicals (1.24 ± 0.02) × 10¹⁰ M⁻¹ s⁻¹ and hydrated electrons (3.1 ± 0.2) × 10⁹ M⁻¹ s⁻¹. Their values indicate that both oxidative and reductive processes in radiolytic decomposition of DCF can take place in irradiated diluted aqueous solutions of DCF. The possibility of decomposition of all examined analytes was investigated in samples of river water and hospital waste. Compared to the previous studies, the conducted measurements in real samples were carried out at the concentration levels, which are close to those reported earlier in environmental samples.
Mostrar más [+] Menos [-]Influence of environmental contamination on pregnancy outcomes Texto completo
2015
Guimarães, Mariana Tavares | Cunha, Michele Granato | Carvalho, Daniele Pena | Ribeiro, Tatyana Sampaio | Martins, Lourdes Conceição | Braga, Alfésio Luís Ferreira | Pereira, Luiz Alberto Amador
This study aims to compare pregnancy outcomes in four contaminated areas to those observed in a non-contaminated area of similar socioeconomic status. A cross-sectional study was carried out. A structured and pre-tested questionnaire was administered to population-based samples of 788–920 families in each of the five studied areas. The exposure assessment used was an ecological measure. Using logistic regression, odds of several pregnancies outcomes (pregnancy occurrence, miscarriage, stillbirth, prematurity, low birth weight, congenital malformation, and multiple births) were estimated after adjustment for potential confounders such as socioeconomic, demographic, and substance abuse factors. We adopted a statistical significance level of 5 %. In three of the four exposed areas, pregnancy occurrence was reduced in comparison to the control area (Area 2, odds ratio (OR) = 0.68, 95 % CI = 0.54–0.86; Area 3, OR = 0.76, 95 % CI = 0.60–0.97; Area 4, OR = 0.71, 95 % CI = 0.56–0.90). Also, a significantly increased odds of miscarriage for living in Area 3 (OR = 1.83, 95 % CI = 1.07–3.12) was found. The other pregnancy outcomes were not significantly elevated in the exposed areas. In conclusion, this study shows evidence of reduced pregnancy occurrence and increased miscarriage occurrence in some of the contaminated areas, compared to the control area.
Mostrar más [+] Menos [-]Ammonium-nitrogen-contaminated groundwater remediation by a sequential three-zone permeable reactive barrier (multibarrier) with oxygen-releasing compound (ORC)/clinoptilolite/spongy iron: column studies Texto completo
2015
Huang, Guoxin | Liu, Fei | Yang, Yingzhao | Kong, Xiangke | Li, Shengpin | Zhang, Ying | Cao, Dejun
A novel sequential permeable reactive barrier (multibarrier), composed of oxygen-releasing compound (ORC)/clinoptilolite/spongy iron zones in series, was proposed for ammonium-nitrogen-contaminated groundwater remediation. Column experiments were performed to: (1) evaluate the overall NH₄⁺–N removal performance of the proposed multibarrier, (2) investigate nitrogen transformation in the three zones, (3) determine the reaction front progress, and (4) explore cleanup mechanisms for inorganic nitrogens. The results showed that NH₄⁺–N percent removal by the multibarrier increased up to 90.43 % after 21 pore volumes (PVs) at the influent dissolved oxygen of 0.68∼2.45 mg/L and pH of 6.76∼7.42. NH₄⁺–N of 4.06∼10.49 mg/L was depleted and NO ₓ ⁻–N (i.e., NO₃⁻–N + NO₂⁻–N) of 4.26∼9.63 mg/L was formed before 98 PVs in the ORC zone. NH₄⁺–N of ≤4.76 mg/L was eliminated in the clinoptilolite zone. NO ₓ ⁻–N of 10.44∼12.80 mg/L was lost before 21 PVs in the spongy iron zone. The clinoptilolite zone length should be reduced to 30 cm. Microbial nitrification played a dominant role in NH₄⁺–N removal in the ORC zone. Ion exchange was majorly responsible for NH₄⁺–N elimination in the clinoptilolite zone. Chemical reduction and hydrogenotrophic denitrification both contributed to NO ₓ ⁻–N transformation, but the chemical reduction capacity decreased after 21 PVs in the spongy iron.
Mostrar más [+] Menos [-]Characterization and environmental risk assessment of heavy metals in construction and demolition wastes from five sources (chemical, metallurgical and light industries, and residential and recycled aggregates) Texto completo
2015
Gao, Xiaofeng | Gu, Yilu | Xie, Tian | Zhen, Guangyin | Huang, Sheng | Zhao, Youcai
Total concentrations of heavy metals (Cu, Zn, Pb, Cr, Cd, and Ni) were measured among 63 samples of construction and demolition (C&D) wastes collected from chemical, metallurgical and light industries, and residential and recycled aggregates within China for risk assessment. The heavy metal contamination was primarily concentrated in the chemical and metallurgical industries, especially in the electroplating factory and zinc smelting plant. High concentrations of Cd were found in light industry samples, while the residential and recycled aggregate samples were severely polluted by Zn. Six most polluted samples were selected for deep research. Mineralogical analysis by X-ray fluorescence (XRF) spectrometry and X-ray diffraction (XRD), combined with element speciation through European Community Bureau of Reference (BCR) sequential extraction, revealed that a relatively slight corrosion happened in the four samples from electroplating plants but high transfer ability for large quantities of Zn and Cu. Lead arsenate existed in the acid extractable fraction in CI7-8 and potassium chromium oxide existed in the mobility fraction. High concentration of Cr could be in amorphous forms existing in CI9. The high content of sodium in the two samples from zinc smelter plants suggested severe deposition and erosion on the workshop floor. Large quantities of Cu existed as copper halide and most of the Zn appeared to be zinc, zinc oxide, barium zinc oxide, and zincite. From the results of the risk assessment code (RAC), the samples from the electroplating factory posed a very high risk of Zn, Cu, and Cr, a high risk of Ni, a middle risk of Pb, and a low risk of Cd. The samples from the zinc smelting plant presented a high risk of Zn, a middle risk of Cu, and a low risk of Pb, Cr, Cd, and Ni.
Mostrar más [+] Menos [-]Exploring factors influencing farmers’ willingness to pay (WTP) for a planned adaptation programme to address climatic issues in agricultural sectors Texto completo
2015
Ahmed, Adeel | Masud, Muhammad Mehedi | Al-Amin, Abul Quasem | Yahaya, Siti Rohani Binti | Rahman, Mahfuzur | Akhtar, Rulia
This study empirically estimates farmers’ willingness to pay (WTP) for a planned adaptation programme for addressing climate issues in Pakistan’s agricultural sectors. The contingent valuation method (CVM) was employed to determine a monetary valuation of farmers’ preferences for a planned adaptation programme by ascertaining the value attached to address climatic issues. The survey was conducted by distributing structured questionnaires among Pakistani farmers. The study found that 67 % of respondents were willing to pay for a planned adaptation programme. However, several socioeconomic and motivational factors exert greater influence on their willingness to pay (WTP). This paper specifies the steps needed for all institutional bodies to better address issues in climate change. The outcomes of this paper will support attempts by policy makers to design an efficient adaptation framework for mitigating and adapting to the adverse impacts of climate change.
Mostrar más [+] Menos [-]Assessment of water quality in urban streams based on larvae of Hydropsyche angustipennis (Insecta, Trichoptera) Texto completo
2015
Tszydel, Mariusz | Markowski, Marcin | Majecki, Janusz | Błońska, Dagmara | Zieliński, Mateusz
Hydropsyche angustipennis (Insecta, Trichoptera) larvae were used as indicators of stream contamination in the city of Łódź, Poland. The larvae of H. angustipennis were present at 9 sampling sites established for this study. Significant differences between the sampling sites were noted for environmental parameters as well as concentration of chemicals in water and biodiversity of aquatic invertebrates. Statistical analyses showed significant correlations between quantity and quality of water pollutants and density of H. angustipennis larvae, concentration of metals in larval bodies, and the appearance of morphological anomalies in tracheal gills and anal papillae. In comparison to literature data, the level of contaminants in water, including heavy metals, for each of the studied streams of Łódź was surprisingly low while concentration of these metals in the whole bodies of H. angustipennis larvae was very high. Some of the heavy metals present in the water might be identified only after conducting analyses of their concentration in the larval bodies. Therefore, long life cycle of H. angustipennis and heavy metal tolerance with a possibility of their accumulation in the larval bodies may constitute a support to traditional chemical assessment of water quality or traditional biomonitoring.
Mostrar más [+] Menos [-]Effect of different nitrogenous nutrients on the cadmium hyperaccumulation efficiency of Rorippa globosa (Turcz.) Thell Texto completo
2015
Wei, Shuhe | Ji, Dandan | Twardowska, Irena | Li, Yunmeng | Zhu, Jiangong
This experiment was used to explore whether the 11 nitrogenous nutrients affect the hyperaccumulation of Rorippa globosa (Turcz.) Thell. to Cd. Pot culture experiments using soil spiked with Cd as CdCl₂·2.5H₂O and 11 nitrogen-containing chemicals were conducted to determine the efficiency of the accumulation of Cd by R. globosa. Application of all 11 nitrogenous nutrients significantly (p < 0.05) enhanced Cd accumulation by R. globosa (Turcz.) Thell. Two major modes of Cd accumulation were observed: (i) through increase of biomass yield without reduction of Cd uptake and (ii) through increase of Cd uptake efficiency in parallel with increase of biomass yield. Bicarbonate > phosphate > chloride compounds of NH₄ enhanced the biomass yield to the greatest extent, while oxalate > nitrate > chloride > and bicarbonate caused a significant increase of Cd uptake by R. globosa. Competition between N and Cd translocation caused either significant reduction of Cd translocation factor or decrease of biomass yield. Of studied nutrients, ammonium bicarbonate NH₄HCO₃ and ammonium chloride NH₄Cl exerted the best joint effect of these two processes on the efficiency of R. globosa as a Cd hyperaccumulator. Application of these chemicals caused increase of Cd concentrations in roots of R. globosa by 35.1 and 41.1 %, and in shoots by 13.9 and 56.4 %, while biomasses of roots increased by 5.8- and 3.8-fold and in shoots by 7.4-fold, and 6.4-fold, respectively, compared to the control. As a result, accumulated load (μg pot⁻¹) of Cd in roots increased by 8.2- and 5.8-fold and in shoots by 8.6- and 10.6-fold in both pots. Consequently, chemicals (NH₄HCO₃ and NH₄Cl) that enhanced both Cd enrichment and biomass yield had the greatest effect on the bioaccumulation capacity of R. globosa.
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