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1.
The temporal and spatial distributions of boundary-layer ozone were studied during June 2000 at Summit, Greenland, using surface-level measurements and vertical profiling from a tethered balloon platform. Three weeks of continuous ozone surface data, 133 meteorological vertical profile data and 82 ozone vertical profile data sets were collected from the surface to a maximum altitude of 1400 m above ground.The lower atmosphere at Summit was characterized by the prevalence of strong stable conditions with strong surface temperature inversions. These inversions reversed to neutral to slightly unstable conditions between ∼9.00 and 18.00 h local time with the formation of shallow mixing heights of ∼70–250 m above the surface.The surface ozone mixing ratio ranged from 39 to 68 ppbv and occasionally had rapid changes of up to 20 ppb in 12 h. The diurnal mean ozone mixing ratio showed diurnal trends indicating meteorological and photochemical controls of surface ozone. Vertical profiles were within the range of 37–76 ppb and showed strong stratification in the lower troposphere. A high correlation of high ozone/low water vapor air masses indicated the transport of high tropospheric/low stratospheric air into the lower boundary layer. A ∼0.1–3 ppb decline of the ozone mixing ratio towards the surface was frequently observed within the neutrally stable mixed layer during midday hours. These data suggest that the boundary-layer ozone mixing ratio and ozone depletion and deposition to the snowpack are influenced by photochemical processes and/or transport phenomena that follow diurnal dependencies. With 37 ppb of ozone being the lowest mixing ratio measured in all data no evidence was seen for the occurrence of ozone depletion episodes similar to those that have been reported within the boundary layer at coastal Arctic sites during springtime.  相似文献   

2.
ABSTRACT

Geologic sequestration appears to be a technically feasible method of storing carbon dioxide in underground aquifers in order to lower greenhouse gas emissions into the atmosphere. The overall feasibility of geologic sequestration is still in question and as such, has been the focus of intense research over the past decade. Researchers have looked to the oil/gas industry and water well industry for lessons learned and technical knowledge, however, a better industry to emulate may well be the waste industry. Viewing geologic sequestration repositories as underground landfills has a great many benefits. First, there is a plethora of existing research and investigations that are directly analogous to geologic sequestration projects. Second, the regulatory framework is rather mature and can be easily adapted to serve geologic sequestration. This paper conducts an extensive literature search of the environmental, waste, and geologic sequestration literature to ascertain planning, design, and operational methodologies, lessons learned, and concepts that are directly useful for geologic sequestration to improve the technical and regulatory framework. Lastly, the paper uses a hypothetical underground landfill geologic sequestration site (ULGSS) in Florida, USA to discuss some of the findings and implications from the literature. It is concluded that there are a number of literature findings from the waste and environmental arena that should be adapted for geologic sequestration.

IMPLICATIONS Geologic sequestration is a promising solution for greenhouse gas control. This work supports that notion but suggests further improvements to the technical and regulatory framework based upon an extensive review of the waste management and environmental literature. The improvements include suggestions in the areas of permitting, site selection, operations, cost accounting, and special waste handling. Some of these improvements are discussed using a hypothetical project site in Florida, USA.  相似文献   

3.
Environmental Science and Pollution Research - The establishment of reference conditions and typology are two important steps in water resources management. The reference conditions enable the...  相似文献   

4.
Environmental Science and Pollution Research - To evaluate the residue levels of fluopimomide, pyraclostrobin and its metabolite BF-500–3 in garlic ecosystems, supervised garlic field trials...  相似文献   

5.
The effects of arbuscular mycorrhizal fungi (AMF) - Glomus intraradices and G. geosporum on arsenic (As) and phosphorus (P) uptake by lowland (Guangyinzhan) and upland rice (Handao 502) were investigated in soil, spiked with and without 60 mg As kg−1. In As-contaminated soil, Guangyinzhan inoculated with G. intraradices or Handao 502 inoculated with G. geosporum enhanced As tolerance, grain P content, grain yield. However, Guangyinzhan inoculated with G. geosporum or Handao 502 inoculated with G. intraradices decreased grain P content, grain yield and the molar ratio of grain P/As content, and increased the As concentration and the ratio of grain/straw As concentration. These results show that rice/AMF combinations had significant (p < 0.05) effects on grain As concentration, grain yield and grain P uptake. The variation in the transfer and uptake of As and P reflected strong functional diversity in AM (arbuscular mycorrhizal) symbioses.  相似文献   

6.

The continuous discharge of diverse chemical products in the environment is nowadays of great concern to the whole world as some of them persist in the environment leading to serious diseases. Several sampling techniques have been used for the characterization of this chemical pollution, although biomonitoring using natural samplers has recently become the technique of choice in this field due to its efficiency, specificity, and low cost. In fact, several living organisms known as biomonitors could accumulate the well-known persistent environmental pollutants allowing their monitoring in the environment. In this work, a review on environmental biomonitoring is presented. The main sampling techniques used for monitoring environmental pollutants are first reported, followed by an overview on well-known natural species used as passive samplers and known as biomonitors. These species include conifer needles, lichen, mosses, bees and their byproducts, and snails, and were widely used in recent research as reliable monitors for environmental pollution.

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7.
Abstract

A simple technique was demonstrated for determining the potential for synthetic organics to stress microbial populations. Oxidized Crowley and Cecil soil materials were amended with varying concentrations of 2,4‐D and methyl parathion, flooded, and then analyzed for changes in pH, redox potential, and levels of soluble plus exchangeable Fe, Mn, and Zn, all of which may be directly or indirectly influenced by the activity of soil microorganisms. At the concentrations tested (up to 75 ppm), there was little effect of 2,4‐D, but methyl parathion apparently did affect microbial activity contributing to changes in the measured soil properties upon flooding. This approach may be a useful technique for screening various compounds for their potential to stress microbial activity that, for many researchers, would be easier than direct observations of microbial parameters such as population numbers and classifications, and enzyme levels.  相似文献   

8.

Background, aim, and scope  

2,2-bis(chlorophenyl)-1,1,1-trichloroethane (DDT) metabolites, other than those routinely measured [i.e., 2,2-bis(chlorophenyl)-1,1-dichloroethylene (DDE) and 2,2-bis(chlorophenyl)-1,1-dichloroethane (DDD)], have recently been detected in elevated concentrations not only in the surface water of Teltow Canal, Berlin, but also in sediment samples from Elbe tributaries (e.g., Mulde and Havel/Spree). This was paralleled by recent reports that multiple other metabolites could emerge from the degradation of parent DDT by naturally occurring organisms or by interaction with some heavy metals. Nevertheless, only very few data on the biological activities of these metabolites are available to date. The objective of this communication is to evaluate, for the first time, the cytotoxicity, dioxin-like activity, and estrogenicity of the least-studied DDT metabolites.  相似文献   

9.
Development and optimisation of alternative strategies to reduce the use of classic chemical inputs for protection against diseases in vineyard is becoming a necessity. Among these strategies, one of the most promising consists in the stimulation and/or potentiation of the grapevine defence responses by the means of elicitors. Elicitors are highly diverse molecules both in nature and origins. This review aims at providing an overview of the current knowledge on these molecules and will highlight their potential efficacy from the laboratory in controlled conditions to vineyards. Recent findings and concepts (especially on plant innate immunity) and the new terminology (microbe-associated molecular patterns, effectors, etc.) are also discussed in this context. Other objectives of this review are to highlight the difficulty of transferring elicitors use and results from the controlled conditions to the vineyard, to determine their practical and effective use in viticulture and to propose ideas for improving their efficacy in non-controlled conditions.  相似文献   

10.
Abstract

This paper reports on the adsorption of different organic pesticides by hydrotalcite, hydrotalcite heated to 500°C and organo‐hydrotalcite in aqueous medium by employing adsorption isotherms, and using X‐ray diffraction and infrared spectroscopy techniques. The results suggest that the adsorption capacity of the different materials depends on their nature as well as on the structure, polarity and hydrophobic or anionic nature of the pesticides. The results also show that hydrotalcite, both natural and after calcination at 500°C, is not a good sorbent of hydrophobic pesticides. The data demonstrated that both types of hydrotalcite, however, are very good sorbents of glyphosphate. Furthermore, the organo‐hydrotalcites may be as good sorbents as organo‐montmorillonites for hydrophobic pesticides.  相似文献   

11.
In the present context of global change and search for sustainability, we detected a gap between restoration and society: local communities are usually only considered as threats or disturbances when planning for restoration. To bridge this gap, we propose a landscape design framework for planning riparian rehabilitation in an urban–rural gradient. A spatial multi-criteria analysis was used to assess the priority of riversides by considering two rehabilitation objectives simultaneously—socio-environmental and ecological—and two sets of criteria were designed according to these objectives. The assessment made it possible to identify 17 priority sites for riparian rehabilitation that were associated with different conditions along the gradient. The double goal setting enabled a dual consideration of citizens, both as beneficiaries and potential impacts to rehabilitation, and the criteria selected incorporated the multi-dimensional nature of the environment. This approach can potentially be adapted and implemented in any other anthropic–natural interface throughout the world.  相似文献   

12.
Anti-cholinesterase insecticides constitute a major portion of modern synthetic pesticides and the assessment of cholinesterase (ChE) inhibition is widely used as a specific biomarker for evaluating the exposure of non-target organisms to these pollutants. However, most studies on this biomarker were developed on vertebrates and among invertebrates, gastropod mollusks are rarely used. Gastropods are important members of aquatic habitats and therefore present a high ecological relevance for freshwater ecosystems. In this context, ChE activities were characterized in two freshwater gastropod mollusks, Potamopyrgus antipodarum and Valvata piscinalis, in order to ascertain their value as sentinel species. Firstly, characterization of ChE activities was performed using different substrates (acetylcholine iodide, butyrylcholine iodide and propionylcholine iodide) and specific inhibitors (eserine, iso-OMPA and BW284c51). Secondly, in vivo effect of a widely used organophosphate insecticide, chlorpyrifos, was tested on ChE activity in both species. Results suggested that P. antipodarum possesses two isoforms of cholinesterases, one isoform which properties are intermediate between an acetyl and a propionyl ChE, and one minor isoform which correspond to a butyryl ChE, while V. piscinalis seems to possess only one isoform which displays typical properties of an acetyl ChE. Chlorpyrifos induced no effect on V. piscinalis ChE. In contrast, P. antipodarum activity was significantly decreased by environmental realistic chlorpyrifos concentrations (2.86 and 14.2 nM) after seven days of contact. The present study suggests that P. antipodarum may be employed as a biological indicator for assessing pesticide contamination.  相似文献   

13.
14.
It was planned to install 305 m (1000 ft) of tubing on a television tower to transport ambient air samples from different height levels to pollutant monitoring instruments at ground level. A feasibility study was undertaken to determine the sorption characteristics of sulfur dioxide and carbon monoxide on various conduit materials. Sorption studies were completed on 30.5 m (100 ft) lengths of 1.3 cm (Y2 in) diam tubings of glass, Teflon, tygon, polypropylene, PVC piping, aluminum, and stainless steel. Final tests were completed on 305 m of 1.9 cm (3/4 in) diam stainless steel tubing. The following variables were investigated: tubing diameter, gas concentration, flowrate through the tubing, temperature, humidity, and the effect of sorption with sulfur dioxide and carbon monoxide alone or together. The parameter ranges studied approximated either atmospheric or air sampling conditions. For carbon monoxide, there was no significant difference between the mean inlet and outlet tubing concentrations under the conditions of the study. With sulfur dioxide, there was neither tubing adsorption nor desorption under the experimental parameters studied, except for tygon, PVC, and aluminum. After a conditioning period with sulfur dioxide, tygon, PVC, and aluminum could also be used as air inlet conduits; tygon is not recommended.  相似文献   

15.
Henry’s law constants H of formaldehyde and benzaldehyde were determined using a dynamic system based on the water/air equilibrium at the interface within the length of a microporous tube. The measurements were conducted over the range 273–293 K in (i) deionized water, (ii) 35 g L?1 solution of NaCl simulating seawater and (iii) two nitric acid solutions, i.e. 0.63 and 6.3 wt%.In pure water, the obtained data were used to derive the following Arrhenius expressions: ln H = (6423 ± 542)/T ? (13.4 ± 2.0) and ln H = (6258 ± 280)/T ? (17.5 ± 1.0) for formaldehyde and benzaldehyde, respectively. The H values, calculated at 293 K from Arrhenius expressions cited above were the following (in units of M atm?1): H = 5020 ± 1170 (formaldehyde), H = 47 ± 5 (benzaldehyde). The temperature dependence of H permits then to derive the solvation enthalpies for both compounds: ΔHsolv = ?(53.4 ± 4.5) kJ mol?1 and ΔHsolv = ?(52.0 ± 2.3) kJ mol?1 for formaldehyde and benzaldehyde, respectively.In 35 g L?1 salt solution, the H values were 27–66% and 12–21% lower than their respective determinations in deionized water, for formaldehyde and benzaldehyde respectively. The observed salt effect was used to estimate the following Setschenow coefficients at 293 K for 0.6 M NaCl: formaldehyde (0.21) and benzaldehyde (0.09).In 6.3 wt% nitric acid solution, H values of benzaldehyde were approximately 30% higher than those found in pure water although no significant influence was observed for formaldehyde.Finally, our experimental data were then used to estimate the fractions of formaldehyde and benzaldehyde in atmospheric aqueous phase and their derived atmospheric lifetimes.  相似文献   

16.
We report the evaluation of changes in water quality, increasing pollution level, of a section of Suquía River basin (Córdoba, Argentina) by using Myriophyllum quitense as bioindicator in addition to the measurement of chemical parameters, combined with chemometrics (ANOVA, Cluster and Discriminant Analysis). Myriophyllum quitense was collected upstream from Córdoba city at an unpolluted site of Suquía River basin. After collection plants were transplanted to different sites with different pollution levels. Subsequent to transplantation plants were weekly collected from the original site as well as from transplantation stations. Water quality was evaluated throughout the transplantation experiment, while the use of this macrophyte as bioindicator was verified through the activation of its antioxidant defenses and biotransformation system. Myriophyllum quitense reacts to the pollution stress increasing the activity of glutathione-S-transferases (CDNB and Fluorodifen), glutathione reductase (GR) and peroxidase (POD). Elevated enzyme activities agreed to different pollution levels, especially inorganic nitrogen loads combined with elevated lead and aluminum concentrations, all of them originated by anthropogenic activities, thus presenting Myriophyllum quitense as a good biomonitor for assessment of water quality in this polluted aquatic ecosystem.  相似文献   

17.
Previous studies have reported that the extent of leaf injury in Nicotiana tabacum “Bel-W3” exposed to environmental conditions in the city of São Paulo is influenced by weather conditions. This influence may occur by means of antioxidant responses. Thus, this study aimed to evaluate whether daily antioxidant responses to environmental variations interfere on the progression of leaf injury on plants of this cultivar during their exposure in a state park of São Paulo and to determine a linear combination of variables, among antioxidants and environmental factors, which mostly explain this visible response. Plants were exposed at the mentioned site for 14 days in four different experiments. During each experiment, three plants were daily sampled to determine the accumulated percentage of leaf area affected by necrosis and antioxidant responses (concentrations of total ascorbic acid (AA) and activity of superoxide dismutase (SOD) and peroxidases (POD)). Ozone concentrations and weather conditions were also daily measured. Pearson correlations and multivariate analyses assessed the relationship between biological and environmental variables. Leaf injury appeared between the 3rd and 6th days of exposure and increased over the exposure periods. The daily concentrations of AA tended to decrease with time of exposure in all experiments, but the activity of SOD and POD oscillated during plant exposure. Positive correlations were observed between AA or SOD and O3 concentrations, as well as negative correlations between AA and air temperature. The increasing percentage of leaf necrosis across the whole period was explained by decreasing levels of AA 2 days before injury estimation and by higher O3 concentrations 5 days before (R2 = 0.36; p < 0.001). The use of N. tabacum Bel-W3 as a bioindicator can be restricted by leaf antioxidant responses to both atmospheric contamination and weather conditions.  相似文献   

18.
Human and ecotoxicological impacts were analyzed in the lower basin of the Coatzacoalcos River (Veracruz, State in Mexico). High pollution levels of contaminants from the oil industry have been reported in natural streams and the Coatzacoalcos River and in their sediments. USEtox? model was employed to evaluate environmental fate, exposure, and effect of nine organic compounds (polycyclic aromatic hydrocarbons and one of which was in the group of polychlorinated biphenyls), a heavy metal (lead), and the effect of the industrial wastewater emitted into the river, on the Coatzacoalcos region. Most of these compounds are highly toxic; they bioaccumulate in human and animal tissue, mainly in the fatty tissues and can damage different organs and systemic targets such as the liver, kidney, hormonal system, nervous system, etc., of both humans and wildlife. The model estimates that 96 % (3,247 kg/day) of organic compounds is transferred from the water into air, whereas only 4 % (151 kg/day) remains in the water. In addition, it predicts that humans are mainly exposed to polychlorinated biphenyls (PCBs) congeners (28 and 153) by eating contaminated fish, due to PCBs accumulating in the fish fat tissue. The number of cases of cancer and noncancer (1 in 862 habitants per additional kilogram) is expected to have an increment due to the higher PCBs exposure of human population. Genetic damages in fishes, earthworms, and toads have been observed and related to higher exposure to organic compounds. The relationship between the field reported data and those one predicted by the USEtox? model have been confirmed empirically by using the nonparametric correlation analysis (Spearman's rho). Based on the USEtox model, the environmental stress in the Coatzacoalcos industrial zone is between 2 and 6 orders of magnitude over geometric mean of acute aquatic EC50s. We think that USEtox model can be used to expand the number of substances that have the current water quality guidelines to improve the water management in Mexico.  相似文献   

19.
Shrimp aquaculture in Vietnam is in the process of being transformed into a major industry around the intensification of the production system. The experiences of other countries in the region, especially in Thailand where high input production systems dominate, suggests that now is a critical time for intervention to redirect industry into pathways that are more sustainable ecologically, socially, and economically. In Thailand, years of experience with intensified systems and a complex industrial organization has not led to sustainable solutions. The challenge here is for society to regain control and then to redirect the transformation along more efficient and benign pathways. Our analyses suggest that current pathways in both countries are unlikely to lead to a sustainable industry. A complete transformation of the way shrimp are grown, fed, processed, distributed, and regulated is needed.  相似文献   

20.
In the 1960s, the Baltic Sea was severely polluted by organic contaminants such as PCBs, HCHs, HCB, and DDTs. Elevated concentrations caused severe adverse effects in Baltic biota. Since then, these substances have been monitored temporally and spatially in Baltic biota, primarily in herring (Clupea harengus) and in guillemot (Uria aalge) egg, but also in cod (Gadus morhua), perch (Perca fluviatilis), eelpout (Zoarces viviparous), and blue mussel (Mytilus edulis). These chemicals were banned in Sweden in the late 1970s/early 1980s. Since the start of monitoring, overall significant decreases of about 70–90 % have been observed. However, concentrations are still higher in the Baltic Sea than in, for example, the North Sea. CB-118 and DDE exceed the suggested target concentrations (24 µg kg?1 lipid weight and 5 µg kg?1 wet weight, respectively) at certain sites in some of the monitored species, showing that concentrations may still be too high to protect the most sensitive organisms.  相似文献   

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