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931.
Onandia G Olsson AK Barth S King JS Uddling J 《Environmental pollution (Barking, Essex : 1987)》2011,159(10):2350-2354
With rising concentrations of both atmospheric carbon dioxide (CO2) and tropospheric ozone (O3), it is important to better understand the interacting effects of these two trace gases on plant physiology affecting land-atmosphere gas exchange. We investigated the effect of growth under elevated CO2 and O3, singly and in combination, on the primary short-term stomatal response to CO2 concentration in paper birch at the Aspen FACE experiment. Leaves from trees grown in elevated CO2 and/or O3 exhibited weaker short-term responses of stomatal conductance to both an increase and a decrease in CO2 concentration from current ambient level. The impairement of the stomatal CO2 response by O3 most likely developed progressively over the growing season as assessed by sap flux measurements. Our results suggest that expectations of plant water-savings and reduced stomatal air pollution uptake under rising atmospheric CO2 may not hold for northern hardwood forests under concurrently rising tropospheric O3. 相似文献
932.
Choung CB Hyne RV Mann RM Stevens MM Hose GC 《Environmental pollution (Barking, Essex : 1987)》2011,159(10):2648-2655
To examine the link between corn agriculture and the observed decline of the endangered southern bell frog (SBF), the effects of two corn crop pesticides on larval growth and development were investigated. Tadpoles were exposed to terbufos sulfone (10 μg/L), a major breakdown product of the insecticide terbufos, and the herbicide atrazine (25 μg/L) individually and as a mixture until the completion of metamorphosis. Atrazine did not interact synergistically with terbufos sulfone or result in significant effects on growth and development alone, although there was some indication of accelerated metamorphosis in the pilot study. Terbufos sulfone alone and as a mixture (terbufos/atrazine) significantly slowed larval development and ultimately delayed metamorphosis. The observed developmental effects from an environmentally relevant concentration of terbufos sulfone indicates a risk posed by this persistent degradation product to the endangered SBF, which breeds and develops in the rice bays adjacent to corn fields treated with pesticides. 相似文献
933.
Gottschalk F Ort C Scholz RW Nowack B 《Environmental pollution (Barking, Essex : 1987)》2011,159(12):3439-3445
Probabilistic material flow analysis and graph theory were combined to calculate predicted environmental concentrations (PECs) of engineered nanomaterials (ENMs) in Swiss rivers: 543 river sections were used to assess the geographical variability of nano-TiO2, nano-ZnO and nano-Ag, and flow measurements over a 20-year period at 21 locations served to evaluate temporal variation. A conservative scenario assuming no ENM removal and an optimistic scenario covering complete ENM transformation/deposition were considered. ENM concentrations varied by a factor 5 due to uncertain ENM emissions (15%-85% quantiles of ENM emissions) and up to a factor of 10 due to temporal river flow variations (15%-85% quantiles of flow). The results indicate highly variable local PECs and a location- and time-dependent risk evaluation. Nano-TiO2 median PECs ranged from 11 to 1′623 ng L−1 (conservative scenario) and from 2 to 1′618 ng L−1 (optimistic scenario). The equivalent values for nano-ZnO and nano-Ag were by factors of 14 and 240 smaller. 相似文献
934.
The goal of this study was to develop a robust method of analyzing surface water samples for S-triazine herbicides, chloroacetanilide herbicides, and their transformation products (TPs) using solid-phase extraction (SPE) followed by liquid chromatograph-mass spectrometry (LC-MS) with electrospray ionization (ESI) by in-source collision-induced dissociation (ISCID) capability of an orthogonal electrospray ionization probe on a single quadrupole LC-MS system. The method developed here met the goals of the study and yielded estimated method detection limits (EMDLs) averaging 0.3 ± 0.1 ng L(-1) for S-triazines and their TPs and 0.7 ± 0.4 ng L(-1) for chloroacetanilides and TPs. Spiked filtered river water yielded SPE recoveries ranging from 94.2 % ± 4.8 % for S-triazines and TPs after eliminating three compounds with less that 65 % recovery from analysis and 95.9 % ± 19 % for chloroacetanilides and their TPs. The method was field-tested with filtered water samples collected from four sites over a four-month period. Detectible values of S-triazines and TPs ranged from 0.3 to 1540 ng L(-1) with a mean of 79.3 and a median of 19.4 ng L(-1). Detectible values for chloroacetanilides and TPs ranged from 0.31 to 3780 ng L(-1) with a mean of 252 and a median of 25.6 ng L(-1). An additional goal was to determine if the method was useful for microbial degradation studies using native bacterial communities. The bacteria transformed atrazine (2-chloro-4-ethylamino-6-isopropylamino-S-triazine) solely into 2-hydroxy atrazine (2-hydroxy-4-ethylamino-6-isopropylamino-S-triazine) with concentrations of 78.4, 63.3 and 32.5 ng L(-1) after 12 days of incubation compared with 6.3 and 7.1 ng L(-1) for control dark and control sunlight respectively. 相似文献
935.
Kabra AN Khandare RV Kurade MB Govindwar SP 《Environmental science and pollution research international》2011,18(8):1360-1373
Purpose
The dyes and dye stuffs present in effluents released from textile dyeing industries are potentially mutagenic and carcinogenic. Phytoremediation technology can be used for remediating sites contaminated with such textile dyeing effluents. The purpose of the work was to explore the potential of Glandularia pulchella (Sweet) Tronc. to decolorize different textile dyes, textile dyeing effluent, and synthetic mixture of dyes. 相似文献936.
Xu H Jiang Y Al-Rasheid KA Al-Farraj SA Song W 《Environmental science and pollution research international》2011,18(7):1213-1221
Introduction
Ciliated protozoa play important roles in aquatic ecosystems especially regarding their functions in micro-food web and have many advantages in environmental assessment compared with most other eukaryotic organisms. The aims of this study were focused on analyzing the application of an indicator based on taxonomic relatedness of ciliated protozoan assemblages for marine environmental assessment. 相似文献937.
Ma BL Blackshaw RE Roy J He T 《Journal of environmental science and health. Part. B》2011,46(7):590-599
Knowledge about the prevalence and diversity of antibiotic resistance genes in soil bacteria communities is required to evaluate the possibility and ecological consequences of the transfer of these genes carried by genetically modified (GM) plants to soil bacteria. The neomycin phosphotransferase gene (nptII) conferring resistance to kanamycin and neomycin is one of the antibiotic resistance genes commonly present in GM plants. In this study, we investigated kanamycin-resistant (Km(R)) and neomycin-resistant (Nm(R)) soil bacterial populations in a 3-year field trial using a commercial GM corn (Zea mays L.) carrying the nptII gene and its near isogenic line. The results showed that a portion (2.3 - 15.6 %) of cultivable soil bacteria was naturally resistant to kanamycin or neomycin. However, no significant difference in the population level of Km(R) or Nm(R) soil bacteria was observed between the GM and non-GM corn fields. The nptII gene was not detected in any of the total 3000 Km(R) or Nm(R) isolates screened by PCR. Further, total soil bacterial cells were collected through Nycodenz gradient centrifugation and bacterial community DNA was subjected to PCR. Detection limit was about 500 cells per gram of fresh soil. Our study suggests that the nptII gene was relatively rare in the soil bacterial populations and there was no evidence of gene transfer from a GM corn plant to soil bacteria based on the data from total soil bacterial communities. 相似文献
938.
Jofré MB Antón RI Caviedes-Vidal E 《Environmental science and pollution research international》2011,19(7):2889-2897
Purpose
Heavy metals have been detected in water and sediments from the Embalse La Florida, an artificial lake in the arid region of San Luis province, Argentina, representing one of the few sources of permanent water for reproduction of native anuran species. This study assesses lead (Pb) and cadmium (Cd) concentrations in the anuran species found in this water reservoir as well as differences between compounds, species and sites of collection.Methods
Adult anuran amphibians were collected on the north and south shores of the Embalse La Florida and Pb and Cd concentrations were measured in whole body homogenates digested using wet ashing techniques.Results
All individuals of the six species assayed had detectable levels of Pb and Cd that ranged from 1.19 to 5.57 ??g/g dry mass and from 1.09 to 6.86 ??g/g dry mass, respectively. Anuran amphibians collected in the more contaminated south shore accumulated 21% more Cd and 40% more Pb than individuals from the less altered north shore. Cd and Pb accumulation was not significantly correlated with the concentration in water at the site of collection.Conclusions
Amphibians of the Embalse La Florida accumulate Cd and Pb. Between and within species, differences were detected in Cd and Pb concentrations. Differences in metal concentrations between species, metals, and individuals collected on shores of the Embalse La Florida with different contamination, were detected. Therefore, it is crucial to implement adequate policies to protect amphibians from the accelerated urban development experienced in this location. 相似文献939.
In this study, we tested the effects of dietary nickel on the activity of glutathione S-transferase (GST), esterases, phenoloxidase, and encapsulation in the haemolymph of larvae of the greater wax moth Galleria mellonella. We also explored the effects of dietary nickel on larval resistance to infection by the fungus Beauveria bassiana. Larvae fed a low dose of nickel (10 μg g−1) had significantly higher GST, phenoloxidase activity and encapsulation responses than controls fed on a nickel-free diet. We also found that larvae fed a sublethal dose of nickel (50 μg g−1) had increased GST, esterase activity and encapsulation rates but decreased phenoloxidase activity. Although, a sublethal dose of dietary nickel enhanced innate immunity, we found that this reduced resistance against the real pathogen. Our results suggest that enhanced immunity and detoxification enzyme activity of insects may not be beneficial to resistance to fungal infection. It appears that there is a trade off between different resistance mechanisms in insects under different metal treatments. 相似文献
940.
McGoldrick DJ Durham J Leknes H Kierkegaard A Gerhards R Powell DE McLachlan MS 《Chemosphere》2011,85(8):1241-1247
Cyclic volatile methyl siloxanes (cVMS) are high volume production chemicals used in a wide range of industrial and consumer products. Three cVMS compounds (D4, D5, and D6) have and are undergoing environmental risk evaluations in several countries and have been proposed for legal regulation in Canada. As interest in monitoring concentrations of these chemicals in the environment increase, there is a need to evaluate the analytical procedures for cVMS in biological matrices in order to assess the quality of data produced. The purpose of this study was to determine laboratory testing performance for measuring residues of D4, D5, and D6 in a standard set of fish homogenate samples and to estimate limits of determination for each substance. The samples sent to each laboratory consisted of homogenized whole body tissues of hatchery raised rainbow trout which were fed food fortified with D4, D5, and D6 (dosed) and trout that were fed standard food rations (control). The participants analyzed each sample using their analytical method of choice using their own standards and procedures for quantification and quality control. With a few exceptions, participating laboratories generated comparable results for D4, D5, and D6 in both the dosed and control samples having z-scores between 2 and −2. Method detection limits for the whole fish matrix were on average 2.4 ng g−1 ww for D4, 2.3 ng g−1 ww for D5, and 1.8 ng g−1 ww for D6. 相似文献