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1.
Development policy increasingly focuses on building capacities to respond to change (adaptation), and to drive change (innovation). Few studies, however, focus specifically on the social and gender differentiation of capacities to adapt and innovate. We address this gap using a qualitative study in three communities in Solomon Islands; a developing country, where rural livelihoods and well-being are tightly tied to agriculture and fisheries. We find the five dimensions of capacity to adapt and to innovate (i.e. assets, flexibility, learning, social organisation, agency) to be mutually dependant. For example, limits to education, physical mobility and agency meant that women and youth, particularly, felt it was difficult to establish relations with external agencies to access technical support or new information important for innovating or adapting. Willingness to bear risk and to challenge social norms hindered both women’s and men’s capacity to innovate, albeit to differing degrees. Our findings are of value to those aspiring for equitable improvements to well-being within dynamic and diverse social–ecological systems.  相似文献   

2.
Simulating the temporal changes of OCP pollution in Hangzhou, China   总被引:4,自引:0,他引:4  
Cao HY  Liang T  Tao S  Zhang CS 《Chemosphere》2007,67(7):1335-1345
A dynamic fugacity model was applied to simulate the changes of contents and transfer fluxes of hexachlorocyclohexane (HCHs) and dichloro-diphenyl-trichloroethane (DDTs) from 1950s in the environment of Hangzhou, China. The receptors are composed of air, surface water, soils, sediment and biota compartments. The model provides a method to combine loadings of HCHs and DDTs from various sources with a series of physical-chemical processes to estimate concentrations and transport fluxes of HCHs and DDTs. Model results suggested that the calculated concentrations were in line with the observed ones. The highest contents of HCH and DDT in the environment of study area were 523 t and 471 t before 1983, among which about 80.7% HCHs and 93.2% DDTs remained in the soil compartment. From 1984 to now, contents of HCHs and DDTs had decreased to about 0.07% and 0.40% of their highest amount (before 1983), and only about 0.001% and 0.014% will expect to be left in 2020 in the study area according to the model prediction. Before 1983, the main transfer fluxes of HCHs were deposition from air to soil, runoff from soil to water and diffusion from soil to air, but for DDTs the main transfer fluxes were deposition from air to soil and water, and transfer from water to sediment. From 1984 to now, runoff from soil to water and transfer from water to sediment became the dominant processes. Although a large amount of HCHs and DDTs had been applied to the study area, their residue levels in the soils were much lower than those in North China (had lesser HCHs and DDTs application than in South China) at present time, and close to other locations of South China (had similar HCHs and DDTs application level). It can be attributed to the high precipitation and temperature that enhances the processes of wet deposition, evaporation and degradation of OCPs. Sensitivities of the input parameters to the calculated concentrations were evaluated using coefficient-of-variation normalized sensitivity coefficients. The model was also subjected to uncertainty analyses using a Monte Carlo simulation.  相似文献   

3.
This study was conducted to evaluate the effect of hairy vetch cover crop residue on runoff losses of atrazine and metolachlor under both no-till corn field plots and from a laboratory runoff system. A 2-year field study was conducted in which losses of atrazine and metolachlor from vetch and non-vetch field plots were determined from the first runoff event after application (5 and 25 days after application in 1997 and 1998, respectively). A laboratory study was conducted using soil chambers, designed to simulate field soil, water, vegetation, and herbicide treatment conditions, subjected to simulated rain events of 5, 6, 20 and 21 days after application, similar to the rainfall pattern observed in the field study. Atrazine losses ranged from 1.2 to 7.2% and 0.01 to 0.08% and metolachlor losses ranged from 0.7 to 3.1% and 0.01 to 0.1% of the amount applied for the 1997 and 1998 runoff events, respectively. In the laboratory study, atrazine runoff losses ranged from 6.7 to 22.7% and 4.2 to 8.5% and metolachlor losses ranged from 3.6 to 9.8% and 1.1 to 4.7% of the amount applied for the 5-6 and 20-21 day events, respectively. The lower losses from the field study were due to smaller rainfall amounts and a series of small rains prior to the runoff event that likely washed herbicides off crop residue and into soil where adsorption could occur. Runoff losses of both herbicides were slightly higher from non-vetch than vetch field plots. Losses from the laboratory study were related to runoff volume rather than vegetation type.  相似文献   

4.
Environmental manipulation experiments showed that species respond individualistically to each environmental-change variable. The greatest responses of plants were generally to nutrient, particularly nitrogen, addition. Summer warming experiments showed that woody plant responses were dominant and that mosses and lichens became less abundant. Responses to warming were controlled by moisture availability and snow cover. Many invertebrates increased population growth in response to summer warming, as long as desiccation was not induced. CO2 and UV-B enrichment experiments showed that plant and animal responses were small. However, some microorganisms and species of fungi were sensitive to increased UV-B and some intensive mutagenic actions could, perhaps, lead to unexpected epidemic outbreaks. Tundra soil heating, CO2 enrichment and amendment with mineral nutrients generally accelerated microbial activity. Algae are likely to dominate cyanobacteria in milder climates. Expected increases in winter freeze-thaw cycles leading to ice-crust formation are likely to severely reduce winter survival rate and disrupt the population dynamics of many terrestrial animals. A deeper snow cover is likely to restrict access to winter pastures by reindeer/caribou and their ability to flee from predators while any earlier onset of the snow-free period is likely to stimulate increased plant growth. Initial species responses to climate change might occur at the sub-species level: an Arctic plant or animal species with high genetic/racial diversity has proved an ability to adapt to different environmental conditions in the past and is likely to do so also in the future. Indigenous knowledge, air photographs, satellite images and monitoring show that changes in the distributions of some species are already occurring: Arctic vegetation is becoming more shrubby and more productive, there have been recent changes in the ranges of caribou, and "new" species of insects and birds previously associated with areas south of the treeline have been recorded. In contrast, almost all Arctic breeding bird species are declining and models predict further quite dramatic reductions of the populations of tundra birds due to warming. Species-climate response surface models predict potential future ranges of current Arctic species that are often markedly reduced and displaced northwards in response to warming. In contrast, invertebrates and microorganisms are very likely to quickly expand their ranges northwards into the Arctic.  相似文献   

5.
Planarian neoblasts are somatic stem cells that have the potential to be used in genotoxicity assays due to their proliferative nature, sensitivity to genotoxic agents, and experimental accessibility. Two freshwater planarian species, Girardia tigrina and Girardia schubarti, were used to develop a neoblast-based micronucleus (MN) assay to assess genotoxicity. Intact or regenerating planarians were exposed to gamma-rays, methyl methanesulphonate (MMS), or cyclophosphamide (CP), and neoblast MN frequency was measured. Exposure to the clastogens had no detectable effect on the MN frequency of intact planarian neoblasts. However, for regenerating individuals, active neoblast proliferation was induced by decapitation, and gamma-ray doses as low as 0.5 Gy, and MMS and CP concentrations as low as 0.8 microM and 100 mM, respectively, induced a significant increase in MN frequency. Exposure to higher doses of gamma-rays consistently resulted in detectable increases in MN frequency. For MMS and CP, concentrations of up to 1.6 microM and 200 mM, respectively, resulted in significant increases in MN frequency, but exposures to higher concentrations led to a decrease to non-significant levels, possibly due to cytotoxic effects of MMS and CP. After completion of regeneration, the MN frequencies returned to those of non-exposed controls, indicating that the neoblast MN assay for regenerating G. tigrina or G. schubarti reflects chromosomal damage caused by acute exposure to clastogenic agents. Upon standardization, this assay may represent an interesting alternative that allows damage caused to freshwater organisms by potentially genotoxic environmental pollutants to be monitored.  相似文献   

6.
Response types in Collembola towards copper in the microenvironment   总被引:7,自引:0,他引:7  
Laboratory studies were carried out to cast light on differences in density responses among collembolan species to copper (Cu)-polluted environments. In a recolonisation experiment, mesofauna originating from a copper (Cupolluted arable field were allowed to colonise defaunated Cu-contaminated and uncontaminated soil cores for 3 months. The abundances of Pseudosinella alba and gamasid mites were higher in the uncontaminated soil, whereas the majority of other collembolans tended to be more abundant in the Cu-enriched soil. Behavioural experiments were conducted to test the ability of single Collembola species to distinguish between filter paper and food soaked in water, Cu, and calcium (Ca) solutions. Onychiurus armatus avoided both Cu and Ca, whereas Folsomia quadrioculata and Folsomia manolachei showed a significant preference for Cu. Isotomurus palustris was not able to distinguish between Cu and water. The results are compared and discussed with regard to other studies on the occurrence and behaviour of Collembola in Cu-contaminated environments. We suggest that microsite selection according to preference or avoidance of high salinity of pore water may partly explain the community structure of Collembola in Cu-polluted soils which are characterised by an increase of euedaphic species. More studies have to be carried out to generalise this concept and to explore to what extent reduced predation by gamasid mites contribute to the success of certain Collembola in Cu-contaminated sites.  相似文献   

7.
Soil vapor extraction (SVE) is typically effective for removal of volatile contaminants from higher-permeability portions of the vadose zone. However, contamination in lower-permeability zones can persist due to mass transfer processes that limit the removal effectiveness. After SVE has been operated for a period of time and the remaining contamination is primarily located in lower-permeability zones, the remedy performance needs to be evaluated to determine whether the SVE system should be optimized, terminated, or transitioned to another technology to replace or augment SVE. Numerical modeling of vapor-phase contaminant transport was used to investigate the correlation between measured vapor-phase mass discharge, MF(r), from a persistent, vadose-zone contaminant source and the resulting groundwater contaminant concentrations. This relationship was shown to be linear, and was used to directly assess SVE remediation progress over time and to determine the level of remediation in the vadose zone necessary to protect groundwater. Although site properties and source characteristics must be specified to establish a unique relation between MF(r) and the groundwater contaminant concentration, this correlation provides insight into SVE performance and support for decisions to optimize or terminate the SVE operation or to transition to another type of treatment.  相似文献   

8.
The COVID-19 pandemic has brought profound social, political, economic, and environmental challenges to the world. The virus may have emerged from wildlife reservoirs linked to environmental disruption, was transmitted to humans via the wildlife trade, and its spread was facilitated by economic globalization. The pandemic arrived at a time when wildfires, high temperatures, floods, and storms amplified human suffering. These challenges call for a powerful response to COVID-19 that addresses social and economic development, climate change, and biodiversity together, offering an opportunity to bring transformational change to the structure and functioning of the global economy. This biodefense can include a “One Health” approach in all relevant sectors; a greener approach to agriculture that minimizes greenhouse gas emissions and leads to healthier diets; sustainable forms of energy; more effective international environmental agreements; post-COVID development that is equitable and sustainable; and nature-compatible international trade. Restoring and enhancing protected areas as part of devoting 50% of the planet’s land to environmentally sound management that conserves biodiversity would also support adaptation to climate change and limit human contact with zoonotic pathogens. The essential links between human health and well-being, biodiversity, and climate change could inspire a new generation of innovators to provide green solutions to enable humans to live in a healthy balance with nature leading to a long-term resilient future.  相似文献   

9.
Increased industrialization of the eastern U.S. over the past several decades has led to regional scale buildup of atmospheric pollutants and concern over possible losses in forest productivity within this region. This paper describes the rationale, methodology, and some preliminary results of a large regional scale study designed to characterize and quantify forest growth impacts attributable to atmospheric stress from both gaseous pollutants and acid rainfall. This research employs a variety of dendroecological techniques to examine the influence of climatic factors, tree age, soil type, competition, and air pollution on tree growth. This broadly collaborative project involves twelve government and university research stations working with a common experimental protocol to examine ≥50 year ringwidth series from approximately 6000 trees distributed over an area extending from Maine to North Carolina and as far west as Missouri. Principal objectives of this research are to determine whether a systematic pattern of decreasing forest growth has occurred, to define its temporal, spatial, and quantitative characteristics, to determine its relationship to differences in soil quality and tree species, and to evaluate its correlation with present and past indices of atmospheric deposition.  相似文献   

10.
In urban areas, a highly variable mixture of pollutants is deposited as particulate matter. The concentration and bioavailability of individual pollutants within particles need to be characterised to ascertain the risks to ecological receptors. This study, carried out at two urban parks, measured the deposition and water-solubility of metals to four species common to UK urban areas. Foliar Cd, Cr, Cu, Fe, Ni, Pb and Zn concentrations were elevated in at least one species compared with those from a rural control site. Concentrations were, however, only affected by distance to road in nettle and, to a lesser extent, birch leaves. Greater concentrations of metal were observed in these species compared to cypress and maple possibly due to differences in plant morphology and leaf surfaces. Solubility appeared to be linked to the size fraction and, therefore, origin of the metal with those present predominantly in the coarse fraction exhibiting low solubility.  相似文献   

11.
Photochemical grid models are addressing an increasing variety of air quality related issues, yet procedures and metrics used to evaluate their performance remain inconsistent. This impacts the ability to place results in quantitative context relative to other models and applications, and to inform the user and affected community of model uncertainties and weaknesses. More consistent evaluations can serve to drive improvements in the modeling process as major weaknesses are identified and addressed. The large number of North American photochemical modeling studies published in the peer-reviewed literature over the past decade affords a rich data set from which to update previously established quantitative performance “benchmarks” for ozone and particulate matter (PM) concentrations. Here we exploit this information to develop new ozone and PM benchmarks (goals and criteria) for three well-established statistical metrics over spatial scales ranging from urban to regional and over temporal scales ranging from episodic to seasonal. We also recommend additional evaluation procedures, statistical metrics, and graphical methods for good practice. While we primarily address modeling and regulatory settings in the United States, these recommendations are relevant to any such applications of state-of-the-science photochemical models. Our primary objective is to promote quantitatively consistent evaluations across different applications, scales, models, model inputs, and configurations. The purpose of benchmarks is to understand how good or poor the results are relative to historical model applications of similar nature and to guide model performance improvements prior to using results for policy assessments. To that end, it also remains critical to evaluate all aspects of the model via diagnostic and dynamic methods. A second objective is to establish a means to assess model performance changes in the future. Statistical metrics and benchmarks need to be revisited periodically as model performance and the characteristics of air quality change in the future.

Implications: We address inconsistent procedures and metrics used to evaluate photochemical model performance, recommend a specific set of statistical metrics, and develop updated quantitative performance benchmarks for those metrics. We promote quantitatively consistent evaluations across different applications, scales, models, inputs, and configurations, thereby (1) improving the user’s ability to quantitatively place results in context and guide model improvements, and (2) better informing users, regulators, and stakeholders of model uncertainties and weaknesses prior to using results for policy assessments. While we primarily address U.S. modeling and regulatory settings, these recommendations are relevant to any such applications of state-of-the-science photochemical models.  相似文献   


12.
A personal air quality model (PAQM) has been developed to estimate the effect of being indoors on total personal exposure to outdoor-generated air pollution. Designed to improve air toxics risk assessment, PAQM accounts for individual hourly activity patterns, indoor-outdoor differences, physical exercise level, and geographic location for up to 56 different population groups. Unique hourly activity profiles are specified for each population group; group members are assigned each hour to one of up to 10 different indoor and outdoor microenvironments. To illustrate PAQM use, we apply it to two example cases: a long-term example representative of situations where pollutant health impact is related to integrated exposure (as in the case of potentially carcinogenic air toxics) and a short-term example representative of situations where health impact is related to acute exposure to peak concentrations (as with ozone).

Case study results illustrate that personal exposure, and thus health risk, attributable to outdoor-generated air pollution is sensitive to indoor-outdoor differences and population mobility. Where health impact is related to long-term integrated exposure (e.g., air toxics), exposure and subsequent risk are likely to be lower than that estimated by previous modeling techniques which do not account for such effects.  相似文献   

13.
Yan ND  Leung B  Keller W  Arnott SE  Gunn JM  Raddum GG 《Ambio》2003,32(3):165-169
Surface water acidity is decreasing in large areas of Europe and North America in response to reductions in atmospheric S deposition, but the ecological responses to these water-quality improvements are uncertain. Biota are recovering in some lakes and rivers, as water quality improves, but they are not yet recovering in others. To make sense of these different responses, and to foster effective management of the acid rain problem, we need to understand 2 things: i) the sequence of ecological steps needed for biotic communities to recover; and ii) where and how to intervene in this process should recovery stall. Here our purpose is to develop conceptual frameworks to serve these 2 needs. In the first framework, the primarily ecological one, a decision tree highlights the sequence of processes necessary for ecological recovery, linking them with management tools and responses to bottlenecks in the process. These bottlenecks are inadequate water quality, an inadequate supply of colonists to permit establishment, and community-level impediments to recovery dynamics. A second, more management-oriented framework identifies where we can intervene to overcome these bottlenecks, and what research is needed to build the models to operationalize the framework. Our ability to assess the benefits of S emission reduction would be simplified if we had models to predict the rate and extent of ecological recovery from acidification. To build such models we must identify the ecological steps in the recovery process. The frameworks we present will advance us towards this goal.  相似文献   

14.
Total nationwide health costs due to air pollution and cigarette smoking were evaluated by determining the percentages of the total respiratory disease cost for 1970 due to the separate and the synergistic effects of smoking and air pollution. Previous studies known to the authors did not properly account for the well established synergistic effect of smoking and air pollution, and also assumed that the urban factor (ratio of urban incidence to rural incidence) was due primarily or exclusively to air pollution. Recent evidence strongly indicates that air pollution is not the primary cause of the urban factor, although it does make a contribution. Taking a minimum of 10% and a maximum of 50% of the urban factor to be due to air pollution, the total 1970 nationwide health cost due to air pollution was found to be between $62 million and $311 million, and the nationwide health cost due to cigarette smoking was found to be $4.23 billion.  相似文献   

15.
Tipping Toward Sustainability: Emerging Pathways of Transformation   总被引:2,自引:0,他引:2  
This article explores the links between agency, institutions, and innovation in navigating shifts and large-scale transformations toward global sustainability. Our central question is whether social and technical innovations can reverse the trends that are challenging critical thresholds and creating tipping points in the earth system, and if not, what conditions are necessary to escape the current lock-in. Large-scale transformations in information technology, nano- and biotechnology, and new energy systems have the potential to significantly improve our lives; but if, in framing them, our globalized society fails to consider the capacity of the biosphere, there is a risk that unsustainable development pathways may be reinforced. Current institutional arrangements, including the lack of incentives for the private sector to innovate for sustainability, and the lags inherent in the path dependent nature of innovation, contribute to lock-in, as does our incapacity to easily grasp the interactions implicit in complex problems, referred to here as the ingenuity gap. Nonetheless, promising social and technical innovations with potential to change unsustainable trajectories need to be nurtured and connected to broad institutional resources and responses. In parallel, institutional entrepreneurs can work to reduce the resilience of dominant institutional systems and position viable shadow alternatives and niche regimes.  相似文献   

16.
The wild tomato species Lycopersicon pimpinellifolium (currant tomato) was exposed to different O3 concentration, both in controlled environment fumigation facilities and in open-top chambers, to assess its sensitivity and to verify its potential as a bioindicator plant. Plants appeared particularly sensitive to O3 at an early stage of growth, responding with typical chlorotic spots within 24 h after exposure to a single pulse of 50 ppb for 3 h, and differentiating peculiar symptoms, such as reddish necrotic stipples, bronzing and extensive necrosis, depending on O3 concentration. Histo-cytochemical investigations with 3,3'-diaminobenzidine, to localize H2O2, and Evans blue, to detect dead cells, suggested that currant tomato sensitivity to O3 could be due to a deficiency in the anti-oxidant pools. The combination of these stainings proved to be useful, either to predict visible symptoms, early before their appearance, and to validate leaf ozone injury.  相似文献   

17.
Dyke PH  Stratford J 《Chemosphere》2002,47(2):103-116
The changes recommended by the World Health Organisation (WHO) to the toxic equivalency factors (TEFs) for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) and the recommendation to extend both the TEF scheme and the tolerable daily intake (TDI) to include "dioxin-like" PCB congeners have significant implications for regulators who have relied heavily on the International TEF (I-TEF) scheme in setting and monitoring limits and exposure to these compounds. This paper examines example data sets of sources, environmental concentrations, food and exposure to indicate likely changes in calculated toxic equivalent (TEQ) due to the recommended changes to TEFs. Many published data sets available do not provide congener specific data for PCDD/F which limits the ability to recalculate TEQs. There are even fewer congener specific data published to enable calculation of TEQs for the dioxin-like PCBs. In general TEQs calculated using the WHO scheme for emissions to air were found to show small increases (in the order of 1-10%) in comparison to the I-TEQ (for PCDD/F), some sludge samples showed substantial decreases (up to 70%). Levels in food and calculations of exposure showed that the change to TEFs for PCDD/F increased calculated exposure by 10-20% while the change to PCB TEFs decreased calculated TEQ attributable to PCB by 0-10%. The effects of including PCB in the overall TEQ and the changes to TEFs for PCDD/F substantially increase calculated TEQ exposure. Congener specific data should be presented to allow calculation of desired TEQ and the impact of the changes on emission limits, regulations on sludge use and environmental quality standards should all be carefully considered. The absence of data on emissions of dioxin-like PCB means that it is not possible to estimate with any certainty the impact on overall TEQ emissions of including the nominated PCB. Given the potential for confusion with the proliferation of TEFs and the extension to include both PCDD/F and PCB in the calculation of TEQs it is important that great care is taken to clearly express which compounds are included and which TEF scheme has been applied in each case.  相似文献   

18.
The advent of stringent regulation of the storage of liquids in underground containers presents a new dimension to an operating practice long taken for granted. Previously, tanks went underground to provide a safe and convenient method for handling.liquids. Unfortunately, the environmental impact of leakage from those containers was not anticipated, nor were tank designs properly configured to minimize the threat. As local officials became alert to the potential for damage, public pressure forced tank owners to rethink this casual practice. Manufacturers and suppliers of tanks and associated hardware have moved rapidly to the new state of the art called for to meet the new standards for storage techniques, and to provide effective leak prevention and detection. This paper presents a chronology of the progress made to date in storage equipment and operating practices to provide the environmental protection demanded of underground tank owners and operators. Tank design, secondary containment, monitoring, spill and overfill protection, tank testing methods, and installation and closure procedures—as related to leak prevention—are presented  相似文献   

19.
Eutrophication of coastal marine environments is a widespread and transboundary problem necessitating consideration of measures to conserve and restore the marine environments that have been adversely affected. As of now, there exist no criteria set for eutrophication of coastal marine waters due to the difficulty to establish single national/international assessment criteria for eutrophication applicable to all coastal waters with different geographic and climatic conditions. However, there appear to be a number of joint and integrated studies among coastal countries to harmonise the outcomes of their scientific research and monitoring activities that might change the natural attributes of the environment. The common findings may then be utilised to develop guidelines on establishing eutrophication criteria together with application of policies and strategies. This study attempts to review the recent efforts of certain groups gathered together and of some countries to develop and improve approaches for assessment of eutrophication in coastal marine waters. Studies of OSPAR Commission, USEPA, and Australia and New Zealand related councils, will also be referred to.  相似文献   

20.
A numerical model of metabolic reductive dechlorination is used to describe the performance of enhanced bioremediation in fractured clay till. The model is developed to simulate field observations of a full scale bioremediation scheme in a fractured clay till and thereby to assess remediation efficiency and timeframe. A relatively simple approach is used to link the fermentation of the electron donor soybean oil to the sequential dechlorination of trichloroethene (TCE) while considering redox conditions and the heterogeneous clay till system (clay till matrix, fractures and sand stringers). The model is tested on lab batch experiments and applied to describe sediment core samples from a TCE-contaminated site. Model simulations compare favorably to field observations and demonstrate that dechlorination may be limited to narrow bioactive zones in the clay matrix around fractures and sand stringers. Field scale simulations show that the injected donor is expected to be depleted after 5 years, and that without donor re-injection contaminant rebound will occur in the high permeability zones and the mass removal will stall at 18%. Long remediation timeframes, if dechlorination is limited to narrow bioactive zones, and the need for additional donor injections to maintain dechlorination activity may limit the efficiency of ERD in low-permeability media. Future work should address the dynamics of the bioactive zones, which is essential to understand for predictions of long term mass removal.  相似文献   

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