A glasshouse pot experiment was conducted to investigate effects of the arbuscular mycorrhizal fungus Glomus mosseae on the growth of Vicia faba and toxicity induced by heavy metals (HMs) (Cu, Zn, Pb and Cd) in a field soil contaminated by a mixture of these metals. There was also uninoculation treatment (NM) simultaneously. Mycorrhizal (GM) plants have significantly increased growth and tolerance to toxicity induced by heavy metals compared with NM plants. P uptake was significantly increased in GM plants. Mycorrhizal symbiosis reduced the transportation of HMs fi'om root to shoot by immobilizing HMs in the mycorrhizal, shown by increasing the ratios of HMs from root to shoot. Oxidative stress, which can induce DNA damage, is an important mechanism of heavy metal toxicity. GM treatment decreased oxidative stress by intricating antioxidative systems such as peroxidases and non-enzymic systems including soluble protein. The DNA damage induced by heavy metals was detected using comet assay, which showed DNA damage in the plants was decreased by the GM treatment. 相似文献
Complex interaction between anthropogenic activities, air quality and human health in urban areas, such as in Cracow sustains the need for the development of an interdisciplinary and integrated risk-assessment methodology. In such purpose, we propose a pilot study performed on asthmatics and based on a combined use of a biomarker, such as metallothionein 2A (MT-2A) in the characterization of human exposure to one or a mixture of pollutants and of Geographical Information Systems (G.I.S.) which integrates climatic and urban anthropogenic parameters in the assessment of spatio-temporal dispersion of air pollutants. Considering global incidence of air pollution on asthma and on peripheral blood lymphocytes MT-2A expression should provide a complementary information on biological risks linked to urban anthropogenic activities. Such study would help for the establishment of a sustainable development in urban areas that can maintain the integrity of air quality and preserve human health. 相似文献
The elemental uptake and the growth response of Spinacia oleracea (spinach) to the soil contaminated with the South African bituminous coal mine dump soil, viz. 0%, 5%, 15%, and 25% w/w, was investigated. The contaminated soils were analyzed for pH, cation exchange capacity (CEC), soil organic matter (SOM), and concentrations of selected heavy metals. The pH, SOM, and CEC decreased with an increase in contamination indicating the acidic nature of coal mine soil and the raise in the soil binding sites. The distribution of Fe, Mn, Ni, Cd, and Pb in the in roots and leaves of the plants was determined in two stages of plant growth. Spinach showed high accumulation of Fe and increased levels of Ni and Cd with an increase in contamination. No plant growth was recorded with 25% contamination. 相似文献
Although emission inventories are the foundation of air quality management and have supported substantial improvements in North American air quality, they have a number of shortcomings that can potentially lead to ineffective air quality management strategies. Major reductions in the largest emissions sources have made accurate inventories of previously minor sources much more important to the understanding and improvement of local air quality. Changes in manufacturing processes, industry types, vehicle technologies, and metropolitan infrastructure are occurring at an increasingly rapid pace, emphasizing the importance of inventories that reflect current conditions. New technologies for measuring source emissions and ambient pollutant concentrations, both at the point of emissions and from remote platforms, are providing novel approaches to collecting data for inventory developers. Advances in information technologies are allowing data to be shared more quickly, more easily, and processed and compared in novel ways that can speed the development of emission inventories. Approaches to improving quantitative measures of inventory uncertainty allow air quality management decisions to take into account the uncertainties associated with emissions estimates, providing more accurate projections of how well alternative strategies may work. This paper discusses applications of these technologies and techniques to improve the accuracy, timeliness, and completeness of emission inventories across North America and outlines a series of eight recommendations aimed at inventory developers and air quality management decision-makers to improve emission inventories and enable them to support effective air quality management decisions for the foreseeable future. 相似文献
Goal, Scope and Background
Some anthropogenic pollutants posses the capacity to disrupt endogenous control of developmental and reproductive processes
in aquatic biota by activating estrogen receptors. Many anthropogenic estrogen receptor agonists (ERAs) are hydrophobic and
will therefore readily partition into the abiotic organic carbon phases present in natural waters. This partitioning process
effectively reduces the proportion of ERAs readily available for bioconcentration by aquatic biota. Results from some studies
have suggested that for many aquatic species, bioconcentration of the freely-dissolved fraction may be the principal route
of uptake for hydrophobic pollutants with logarithm n-octanol/water partition coefficient (log Kow) values less than approximately
6.0, which includes the majority of known anthropogenic ERAs. The detection and identification of freely-dissolved readily
bioconcentratable ERAs is therefore an important aspect of exposure and risk assessment. However, most studies use conventional
techniques to sample total ERA concentrations and in doing so frequently fail to account for bioconcentration of the freely-dissolved
fraction. The aim of the current study was to couple the biomimetic sampling properties of semipermeable membrane devices
(SPMDs) to a bioassay-directed chemical analysis (BDCA) scheme for the detection and identification of readily bioconcentratable
ERAs in surface waters.
Methods
SPMDs were constructed and deployed at a number of sites in Germany and the UK. Following the dialytic recovery of target
compounds and size exclusion chromatographic clean-up, SPMD samples were fractionated using a reverse-phase HPLC method calibrated
to provide an estimation of target analyte log Kow. A portion of each HPLC fraction was then subjected to the yeast estrogen
screen (YES) to determine estrogenic potential. Results were plotted in the form of 'estrograms' which displayed profiles
of estrogenic potential as a function of HPLC retention time (i.e. hydrophobicity) for each of the samples. Where significant
activity was elicited in the YES, the remaining portion of the respective active fraction was subjected to GC-MS analysis
in an attempt to identify the ERAs present.
Results and Discussion
Estrograms from each of the field samples showed that readily bioconcentratable ERAs were present at each of the sampling
sites. Estimated log Kow values for the various active fractions ranged from 1.92 to 8.63. For some samples, estrogenic potential
was associated with a relatively narrow range of log Kow values whilst in others estrogenic potential was more widely distributed
across the respective estrograms. ERAs identified in active fractions included some benzophenones, various nonylphenol isomers,
benzyl butyl phthalate, dehydroabietic acid, sitosterol, 3-(4-methylbenzylidine)camphor (4-MBC) and 6-acetyl-1,1,2,4,4,7-hexamethyltetralin
(AHTN). Other tentatively identified compounds which may have contributed to the observed YES activity included various polycyclic
aromatic hydrocarbons (PAHs) and their alkylated derivatives, methylated benzylphenols, various alkylphenols and dialkylphenols.
However, potential ERAs present in some active fractions remain unidentified.
Conclusions and Outlook
Our results show that SPMD-YES-based BDCA can be used to detect and identify readily bioconcentratable ERAs in surface waters.
As such, this biomimetic approach can be employed as an alternative to conventional methodologies to provide investigators
with a more environmentally relevant insight into the distribution and identity of ERAs in surface waters. The use of alternative
bioassays also has the potential to expand SPMD-based BDCA to include a wide range of toxicological endpoints. Improvements
to the analytical methodology used to identify ERAs or other target compounds in active fractions in the current study could
greatly enhance the applicability of the methodology to risk assessment and monitoring programmes. 相似文献
Biphenyl could be successfully degraded by Burkholderia xenovorans LB400, initially described as Pseudomonas sp. LB400, in two-phase partitioning bioreactors (TPPBs). TPPBs are comprised of an aqueous, cell containing phase, and an immiscible, biocompatible organic phase that partitions toxic and/or poorly soluble substrates (in this case biphenyl) based on maintaining a thermodynamic equilibrium. The critical LogKO/W of the organism was found to be approximately 5.5, indicating that solvents with a LogKO/W larger than 5.5 are suitable as delivery phases for B. xenovorans LB400. Two solvents selected for the TPPB system were octadecene and bis(2-ethylhexyl)sebacate (BES). In one experiment a total of 6.6 g biphenyl per l aqueous-phase-equivalent (biphenyl delivered in solvent, at an aqueous phase to solvent ratio of 10) could be degraded in 25 h during batch operation with octadecene. The specific growth rate and the half saturation constant of the Monod model were estimated to be mumax=0.25 h-1 and KS=0.0001 g l-1, and the yield coefficient was YX/S=0.48 g biomass per g biphenyl. These parameter estimates were used to predict the time course of biphenyl degradation at different initial substrate concentrations and with biphenyl delivered from the two solvents with different partitioning behaviour for biphenyl. The predictions were validated by experimental data, confirming the microbial kinetics as well as the expected partitioning effects. 相似文献
The rapid urbanisation of the twentieth century, along with the spread of high-consumption urban lifestyles, has led to cities becoming the dominant drivers of global anthropogenic greenhouse gas emissions. Reducing these impacts is crucial, but production-based frameworks of carbon measurement and mitigation—which encompass only a limited part of cities’ carbon footprints—are much more developed and widely applied than consumption-based approaches that consider the embedded carbon effectively imported into a city. Frequently, therefore, cities are left blind to the importance of their wider consumption-related climate impacts, while at the same time left lacking effective tools to reduce them. To explore the relevance of these issues, we implement methodologies for assessing production- and consumption-based emissions at the city-level and estimate the associated emissions trajectories for Bristol, a major UK city, from 2000 to 2035. We develop mitigation scenarios targeted at reducing the former, considering potential energy, carbon and financial savings in each case. We then compare these mitigation potentials with local government ambitions and Bristol’s consumption-based emissions trajectory. Our results suggest that the city’s consumption-based emissions are three times the production-based emissions, largely due to the impacts of imported food and drink. We find that low-carbon investments of circa £3 billion could reduce production-based emissions by 25% in 2035. However, we also find that this represents <10% of Bristol’s forecast consumption-based emissions for 2035 and is approximately equal to the mitigation achievable by eliminating the city’s current levels of food waste. Such observations suggest that incorporating consumption-based emission statistics into cities’ accounting and decision-making processes could uncover largely unrecognised opportunities for mitigation that are likely to be essential for achieving deep decarbonisation.
Socioecological models predict that contest competition for clumped foods can lead to higher energy intake and lower energy expenditure for higher-ranking individuals. Here, we examine the relationships between dominance rank and energy intake and expenditure of female mountain gorillas in Bwindi Impenetrable National Park, Uganda (Gorilla beringei beringei). Bwindi gorillas have weak dominance relationships, feed on nonreproductive plant parts throughout the year, and consume fruit when it is seasonally available. We used behavioral observations on one group of gorillas and nutritional analysis of their major food items to calculate energy intake rates and estimated energy expenditure. Using linear mixed models, we found a significant positive relationship between dominance rank and energy intake rates, due to higher-ranking females having faster ingestion rates, rather than consuming foods with higher energy concentrations. Lower-ranking females did not spend significantly more time feeding to compensate for their lower energy intake rates. Lower-ranking females spent significantly more time traveling than higher-ranking females, leading to a negative relationship between dominance rank and energy expenditure. The combined results revealed a significant positive relationship between dominance rank and energy balance. Higher-ranking females did not spend longer feeding on fruit than lower-ranking ones, and the relationship between dominance rank and energy intake rates was not stronger when fruit was available. According to socioecological models, these results suggest that contest competition may be occurring with both fruit and nonreproductive plant parts, which would be consistent with growing evidence that nonreproductive plant parts can be contestable. 相似文献