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51.
Bunnell JE Tatu CA Bushon RN Stoeckel DM Brady AM Beck M Lerch HE McGee B Hanson BC Shi R Orem WH 《Environmental geochemistry and health》2006,28(6):577-587
In May and September, 2002, 14 private residential drinking water wells, one dewatering well at a lignite mine, eight surface
water sites, and lignite from an active coal mine were sampled in five Parishes of northwestern Louisiana, USA. Using a geographic
information system (GIS), wells were selected that were likely to draw water that had been in contact with lignite; control
wells were located in areas devoid of lignite deposits. Well water samples were analyzed for pH, conductivity, organic compounds,
and nutrient and anion concentrations. All samples were further tested for presence of fungi (cultures maintained for up to
28 days and colonies counted and identified microscopically) and for metal and trace element concentration by inductively-coupled
plasma mass spectrometry and atomic emission spectrometry. Surface water samples were tested for dissolved oxygen and presence
of pathogenic leptospiral bacteria. The Spearman correlation method was used to assess the association between the endpoints
for these field/laboratory analyses and incidence of cancer of the renal pelvis (RPC) based on data obtained from the Louisiana
Tumor Registry for the five Parishes included in the study. Significant associations were revealed between the cancer rate
and the presence in drinking water of organic compounds, the fungi Zygomycetes, the nutrients PO4 and NH3, and 13 chemical elements. Presence of human pathogenic leptospires was detected in four out of eight (50%) of the surface
water sites sampled. The present study of a stable rural population examined possible linkages between aquifers containing
chemically reactive lignite deposits, hydrologic conditions favorable to the␣leaching and transport of toxic organic compounds
from the lignite into the groundwater, possible microbial contamination, and RPC risk. 相似文献
52.
Electrokinetic enhancement of phenanthrene biodegradation in creosote-polluted clay soil 总被引:5,自引:0,他引:5
Niqui-Arroyo JL Bueno-Montes M Posada-Baquero R Ortega-Calvo JJ 《Environmental pollution (Barking, Essex : 1987)》2006,142(2):326-332
Given the difficulties caused by low-permeable soils in bioremediation, a new electrokinetic technology is proposed, based on laboratory results with phenanthrene, to afford bioremediation of polycyclic aromatic hydrocarbons (PAH) in clay soils. Microbial activity in a clay soil historically polluted with creosote was promoted using a specially designed electrokinetic cell with a permanent anode-to-cathode flow and controlled pH. The rates of phenanthrene losses during treatment were tenfold higher in soil treated with an electric field than in the control cells without current or microbial activity. Results from experiments with Tenax-assisted desorption and mineralization of 14C-labeled phenanthrene indicated that phenanthrene biodegradation was limited by mass-transfer of the chemical. We suggest that the enhancement effect of the applied electric field on phenanthrene biodegradation resulted from mobilization of the PAH and nutrients dissolved in the soil fluids. 相似文献
53.
Nitrous oxide nitrification and denitrification 15N enrichment factors from Amazon forest soils. 总被引:1,自引:0,他引:1
Tibisay Pérez Diana Garcia-Montiel Susan Trumbore Stanley Tyler Plínio de Camargo Marcelo Moreira Marisa Piccolo Carlos Cerri 《Ecological applications》2006,16(6):2153-2167
The isotopic signatures of 15N and 18O in N2O emitted from tropical soils vary both spatially and temporally, leading to large uncertainty in the overall tropical source signature and thereby limiting the utility of isotopes in constraining the global N2O budget. Determining the reasons for spatial and temporal variations in isotope signatures requires that we know the isotope enrichment factors for nitrification and denitrification, the two processes that produce N2O in soils. We have devised a method for measuring these enrichment factors using soil incubation experiments and report results from this method for three rain forest soils collected in the Brazilian Amazon: soil with differing sand and clay content from the Tapajos National Forest (TNF) near Santarém, Pará, and Nova Vida Farm, Rond?nia. The 15N enrichment factors for nitrification and denitrification differ with soil texture and site: -111 per thousand +/- 12 per thousand and -31 per thousand +/- 11 per thousand for a clay-rich Oxisol (TNF), -102 per thousand +/- 5 per thousand and -45 per thousand +/- 5 per thousand for a sandier Ultisol (TNF), and -10.4 per thousand +/- 3.5 per thousand (enrichment factor for denitrification) for another Ultisol (Nova Vida) soil, respectively. We also show that the isotopomer site preference (delta15Nalpha - delta15Nbeta, where alpha indicates the central nitrogen atom and beta the terminal nitrogen atom in N2O) may allow differentiation between processes of production and consumption of N2O and can potentially be used to determine the contributions of nitrification and denitrification. The site preferences for nitrification and denitrification from the TNF-Ultisol incubated soils are: 4.2 per thousand +/- 8.4 per thousand and 31.6 per thousand +/- 8.1 per thousand, respectively. Thus, nitrifying and denitrifying bacteria populations under the conditions of our study exhibit significantly different 15N site preference fingerprints. Our data set strongly suggests that N2O isotopomers can be used in concert with traditional N2O stable isotope measurements as constraints to differentiate microbial N2O processes in soil and will contribute to interpretations of the isotopic site preference N2O values found in the free troposphere. 相似文献
54.
Diego Gil Alfonso Marzal Florentino de Lope Marisa Puerta Anders P. Møller 《Behavioral ecology and sociobiology》2006,60(1):96-100
Female birds deposit in the yolks of eggs substantial amounts of androgens, such as testosterone and androstenedione. These
androgens have been shown to speed up nestling development, induce a fast development of ornaments and increase dominance
in adults. Experiments in several species have reported that females invest greater amounts of androgens in the eggs fathered
by attractive males, suggesting that yolk androgen is a costly investment for either the offspring or the mother. There is
some evidence that nestling immunocompetence may be partially suppressed by high levels of yolk androgens, but it is not known
whether this is also the case for females. We tested this hypothesis in the house martin by inducing an immune challenge through
an injection of sheep red blood cells, a standard challenge of the humoral immune system. Experimental birds laid eggs with
lower amounts of yolk androstenedione than controls, and there was a similar non-significant trend for testosterone. Furthermore,
the probability of laying a replacement clutch was higher for birds that had laid a first clutch with relatively high levels
of yolk testosterone. These results suggest that yolk androgen deposition is limited by immune costs in the female, and that
only females in good condition may afford to invest high levels of androgen in eggs in this species. 相似文献
55.
Gabriele Klumpp Andreas Klumpp Marisa Domingos Robert Guderian 《Environmental monitoring and assessment》1995,35(1):27-42
In the frame of an active monitoring study at the Serra do Mar near the industrial pool of Cubatão, Brazil,Hemerocallis was tested for its suitability as bioindicator of airborne fluoride pollution. In a screening experiment with various cultivars comparison of susceptibility, correlation of visible injury and foliar fluoride concentration as well as comparison with exposure ofGladiolus gave best results for theHemerocallis cultivar ‘Red Moon’. When exposed simultaneously foliar fluoride accumulation ofHemerocallis showed a highly significant linear correlation with fluoride content ofLolium multiflorum, the ‘standardized grass culture’ andGladiolus, well-known bioindicator species for fluoride impact. With respect to the extent of foliar injuryHemerocallis was less sensitive thanGladiolus, in terms of accumulation capacity it ranged betweenLolium andGladiolus. In general, the results of the biomonitoring study proved that the Atlantic Forest vegetation in a valley downwind from the Cubatão fertilizer industries is still suffering from severe fluoride pollution. 相似文献
56.
Marisa Casale Scott Drimie Timothy Quinlan Gina Ziervogel 《Regional Environmental Change》2010,10(2):157-168
Within southern Africa, many households are facing increasing pressures as they deal with multiple challenges such as low
employment, high levels of disease, environmental resources under pressure and changing political landscapes. To respond to
the needs of different individuals and households, it is important to define the nature of their vulnerability. An increasing
amount of theoretical and empirical work on the concept of ‘vulnerability’ has led to a range of definitions, indicators and
measurement tools, which have come to characterise this field of study. As a result, there is no one general consensus. This
paper presents the results from the latest in a series of applied studies conducted since 2004 by a network of scientists
working in southern Africa, aimed at refining the definition and application of the concept of vulnerability. The study employed
a recently developed multiple-stressor model to guide the collection and analysis of data from three sites in South Africa
and Malawi. In this paper, we identify and explore five key ‘symptoms’ of vulnerability emerging from our multi-country data
and reflect on the usefulness of the model employed. 相似文献
57.
Christiane D. Vitzthum von Eckstaedt Marisa Ioppolo-ArmaniosDavid Kelly Mark Gibberd 《Chemosphere》2012,89(11):1407-1413
This study presents carbon (δ13C) and hydrogen (δD) isotope values of volatile organic compounds (VOCs) in various emission sources using thermal desorption-gas chromatography-isotope ratio mass spectrometry (TD-GC-irMS). The investigated VOCs ranged from C6 to C10. Samples were taken from (i) car exhaust emissions as well as from plant combustion experiments of (ii) various C3 and (iii) various C4 plants. We found significant differences in δ values of analysed VOCs between these sources, e.g. δ13C of benzene ranged between (i) −21.7 ± 0.2‰, (ii) −27.6 ± 1.6‰ and (iii) −16.3 ± 2.2‰, respectively and δD of benzene ranged between (i) −73 ± 13‰, (ii) −111 ± 10‰ and (iii) −70 ± 24‰, respectively. Results of VOCs present in investigated emission sources were compared to values from the literature (aluminium refinery emission). All source groups could be clearly distinguished using the dual approach of δ13C and δD analysis. The results of this study indicate that the correlation of compound specific carbon and hydrogen isotope analysis provides the potential for future research to trace the fate and to determine the origin of VOCs in the atmosphere using thermal desorption compound specific isotope analysis. 相似文献
58.
Ferreira MI Domingos M Gomes Hde A Saldiva PH de Assunção JV 《Environmental pollution (Barking, Essex : 1987)》2007,146(1):219-224
We report seasonal variation in CH(4) and N(2)O emission rate from solid storage of bovine manure in Delhi as well as emission factors and emission inventory from manure management systems in India. Emission flux observed in the year 2002-2003 was 4.29+/-1, 4.84+/-2.44 and 12.92+/-4.25 mg CH(4)kg(-1)dung day(-1), as well as 31.29+/-4.93, 72.11+/-16.22 and 6.39+/-1.76 microgN(2)O kg(-1)dung day(-1) in winter, summer and rainy seasons, respectively. CH(4) emission factors varied from 0.8 to 3.3 kg hd(-1)year(-1) for bovines and were lower than IPCC-1996 default values. N(2)O emission factors varied from 3 to 11.7 mg hd(-1)year(-1) from solid storage of manure. Inventory estimates were found to about 698+/-27 Gg CH(4) from all manure management systems and 2.3+/-0.46 tons of N(2)O from solid storage of manure for the year 2000. 相似文献
59.
Poliana Cardoso-Gustavson Francine Faia Fernandes Edenise Segala Alves Mariana Pereira Victorio Barbara Baesso Moura Marisa Domingos Caroline Albuquerque Rodrigues Andreza Portella Ribeiro Catarina Carvalho Nievola Ana Maria G Figueiredo 《Environmental science and pollution research international》2016,23(2):1779-1788
60.