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1.
Application of bioassays in toxicological hazard, risk and impact assessments of dredged sediments 总被引：1，自引：0，他引：1
Given the potential environmental consequences of dumped dredged harbour sediments it is vital to establish the potential risks from exposure before disposal at sea. Currently, European legislation for disposal of contaminated sediments at sea is based on chemical analysis of a limited number of well-known contaminants for which maximum acceptable concentrations, action levels (ALs), have been set. The present paper addresses the issue of the applicability of in vitro and in vivo bioassays for hazard, risk and local impact assessment of dredged polluted sediments to be disposed of at sea. It discusses how and to what extent selected bioassays can fill in the gaps left open by chemical analysis and the way in which the bioassays may contribute to the present licensing system for disposal. Three different purposes for application were distinguished: the most basic application (A) is a rapid determination of the hazard (potential toxicity) of dredged sediments which is then compared to ALs in a licensing system. As with chemical analysis on whole sediment extracts, the bioavailability of the chemicals is not taken into account. As in vitro assays with sediment extracts are not sensitive to matrix effects, a selection of specific in vitro bioassays can be suitable fast and standardized additions for the licensing system. When the outcome of (A) does not convincingly demonstrate whether the sediment is clean enough or too polluted, further bioanalysis can help the decision making process (B). More aspects of the mostly unknown complex chemical mixtures are taken into account, including the bioavailability and chronic toxicity focusing on ecologically relevant endpoints. The ecotoxicological pressure imposed by the dredged sediments can be quantified as the potentially affected fraction (PAF) based on chemical or biological analysis of levels of contaminants in sediment or biota. To validate the predicted risk, the actual impact of dumped harbour sediments on local ecosystems (C) can be determined using a dedicated set of in vitro and in vivo bioassays as well as bio-indicators selected based on the information obtained from (A) and (B) and on the characteristics of the local ecosystem. Conversely, the local sediment impact assessment (C) can direct fine-tuning of the selection of chemical and bioassay analyses and for setting safe levels in the licensing system. It is concluded that in vitro and in vivo bioassays and biological indicators are useful tools in the process of hazard, ecotoxicological risk and impact assessment of dredged harbour sediments, provided they are consciously chosen and quality criteria for assay performance are defined. 相似文献
2.
Hylland K 《Marine pollution bulletin》2006,53(10-12):614-619
Coastal ecosystems are impacted by many stressors, of which chemicals are possibly not the most important. Chemicals differ from most other stressors such as eutrophication and hypersedimentation in the time scale-effects from the latter act on the scale of weeks or months, whereas effects from chemicals may take years to manifest themselves in population or community changes. There are four different approaches available to manage chemicals in marine ecosystems: target contaminant levels, target individual effects, target community impacts (biodiversity) and, finally, target processes. These four differ in the analytical methods available and the analyst's ability to separate effects from chemicals from other environmental factors and natural variation. There is furthermore, a need to develop a framework to integrate biological effects methods with risk assessment methodology. Such integration will improve the basis for risk-based assessment of chemicals. A problematic issue relevant to all aspects of environmental management are the interactions between chemicals, and between chemicals and eutrophication or sedimentation. There is a clear need for more knowledge about such interactions. 相似文献
3.
George E. DeVaull Ileana A. L. Rhodes Emiliano Hinojosa Cristin L. Bruce 《Ground Water Monitoring & Remediation》2020,40(4):44-53
Spills and releases of hydrocarbons may result in zones of nonaqueous phase liquids (NAPL) within soils and groundwater. The NAPL will change, or “weather” over time due to a range of physical, chemical, and biological processes. Hydrocarbon constituents in environmental samples collected from NAPL-impacted groundwater wells, sediments, or soils vary in composition over time due to weathering. The changing composition can be used to estimate mass depletion rates and trends for the bulk NAPL and for individual constituent chemicals relative to marker constituents which are less susceptible to weathering. Methods for the selection of marker constituents and for quantitatively and conservatively estimating NAPL depletion rates and trends over time are shown. Estimates are included for two sites with different NAPL mixtures present (crude oil and gasoline/diesel-range product), for which depletion of half the initial total NAPL is estimated at 13.6 ± 2.9 years and 7.3 ± 1.8 years respectively, and with no active NAPL remediation at either site. Similar methods for oil or NAPL depletion estimates have often relied on a prior-identified suite of presumed-conserved marker constituents. The method presented here includes steps which identify the best set of analyzed candidate marker constituents in a NAPL mixture. This can confirm prior-selected markers but is particularly useful for NAPL mixtures in which no prior-identified marker constituents are present. 相似文献
4.
Beaumont NJ Austen MC Atkins JP Burdon D Degraer S Dentinho TP Derous S Holm P Horton T van Ierland E Marboe AH Starkey DJ Townsend M Zarzycki T 《Marine pollution bulletin》2007,54(3):253-265
This paper identifies and defines ecosystem goods and services provided by marine biodiversity. Case studies have been used to provide an insight into the practical issues associated with the assessment of marine ecosystem goods and services at specific locations. The aim of this research was to validate the definitions of goods and services, and to identify knowledge gaps and likely difficulties of quantifying the goods and services. A validated theoretical framework for the assessment of goods and services is detailed, and examples of the goods and services at a variety of case study areas are documented. These results will enable future assessments of marine ecosystem goods and services. It is concluded that the utilisation of this goods and services approach has the capacity to play a fundamental role in the Ecosystem Approach, by enabling the pressures and demands of society, the economy and the environment to be integrated into environmental management. 相似文献
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In this study, we propose a simple hydrophobicity-based approach to predict the toxicity of mixtures of marine organic micropollutants. Fifty mixtures were chosen, comprising individual chemicals randomly chosen from three halogenated benzenes, three phenols, two petroleum hydrocarbons, three polychlorinated biphenyls (PCBs), four organochlorine pesticides (OCPs) and two herbicides, with the intention of simulating the mixtures of organic micropollutants that may exist in some marine waters. The hydrophobicity of the mixtures was quantified by measuring the C(18)-Empore(TM) disk/water partition coefficients (K(MD)). A K(MD)-based approach was proposed to describe their toxicity to Photobacterium phosphoreum, and the application of this approach to another 10 related mixtures proved its predictive capability, as indicated by the consistency between the predicted and observed toxicities (r(2)=0.905, SE=0.101, and F=76.325 at P<0.001). This predictive capability convinces us that the K(MD)-based approach provides a general approach to predicting the toxicity of mixtures of organic micropollutants in marine water. 相似文献
7.
Thorsten Wagener Simon J. Dadson David M. Hannah Gemma Coxon Keith Beven John P. Bloomfield Wouter Buytaert Hannah Cloke Paul Bates Joseph Holden Louise Parry Rob Lamb Nick A. Chappell Matthew Fry Gareth Old 《水文研究》2021,35(7):e14288
There is a no lack of significant open questions in the field of hydrology. How will hydrological connectivity between freshwater bodies be altered by future human alterations to the hydrological cycle? Where does water go when it rains? Or what is the future space–time variability of flood and drought events? However, the answers to these questions will vary with location due to the specific and often poorly understood local boundary conditions and system properties that control the functional behaviour of a catchment or any other hydrologic control volume. We suggest that an open, shared and evolving perceptual model of a region's hydrology is critical to tailor our science questions, as it would be for any other study domain from the plot to the continental scale. In this opinion piece, we begin to discuss the elements of and point out some knowledge gaps in the perceptual model of the terrestrial water cycle of Great Britain. We discuss six major knowledge gaps and propose four key ways to reduce them. While the specific knowledge gaps in our perceptual model do not necessarily transfer to other places, we believe that the development of such perceptual models should be at the core of the debate for all hydrologic communities, and we encourage others to have a similar debate for their hydrologic domain. 相似文献
8.
Independent Component Analysis (ICA) represents a higher-order statistical technique that is often used to separate mixtures of stochastic random signals into statistically independent sources. Its benefit is that it only relies on the information contained in the observations, i.e. no parametric a-priori models are prescribed to extract the source signals. The mathematical foundation of ICA, however, is rooted in the theory of random signals. This has led to questions whether the application of ICA to deterministic signals can be justified at all? In this context, the possibility of using ICA to separate deterministic signals such as complex sinusoidal cycles has been subjected to previous studies. In many geophysical and geodetic applications, however, understanding long-term trend in the presence of periodical components of an observed phenomenon is desirable. In this study, therefore, we extend the previous studies with mathematically proving that the ICA algorithm with diagonalizing the 4th order cumulant tensor, through the rotation of experimental orthogonal functions, will indeed perfectly separate an unknown mixture of trend and sinusoidal signals in the data, provided that the length of the data set is infinite. In other words, we justify the application of ICA to those deterministic signals that are most relevant in geodetic and geophysical applications. 相似文献
9.
KINETIC MODELING OF CONSTITUTIVE RELATIONS FOR PARTICLE MOTION IN LOW TO MODERATELY CONCENTRATED FLOWS 总被引：1，自引：0，他引：1
Guangqian WANG Xudong FU Xingkui WANG 《国际泥沙研究》2005,20(4):305-318
Formulating underlying mechanisms of concentrated solid-liquid flows is essential for simulation of various industrial processes and natural phenomena. A generalized constitutive model for particle motion in flows with low to moderate solids concentrations is developed. This generalized model facilitates characterization of inelastic collisions, particle-fluid interactions, and shearing effects. Moderately concentrated simple shear flows of a sand-water mixture are analyzed, and comparisons of model predictions and experimental data are in good agreement. This model exhibits sound performance in characterizing particle motion for wide ranges of concentration and shear rate, and may supply a reasonable and competent alternative to previous models developed for dilute and rapid-granular flows when applied to moderately concentrated situations. The concentration approaches zero （C --~ O） asymptote is observed at a relatively high shear rate in model predictions. Assumption of low collisional dissipation of the particle phase as C → 0 is more reasonable for this observation, compared to that without the interstitial fluid effect. Accurately modeling energy dissipation is important for characterizing the stability of dilute simple shear flows of solid-liquid mixtures. Incorporating friction forces will also facilitate improvement of the applicability of this generalized model to flows at extremely high concentrations. 相似文献
10.
John P. Sumpter 《洁净——土壤、空气、水》2005,33(1):9-16
Although a relatively new area of environmental research, the field of endocrine disruption has grown very rapidly, and currently many hundreds, perhaps even a few thousand, papers are published annually on the many different aspects covered by the field. As far as endocrine disruption in wildlife is concerned, most attention has been focused on aquatic organisms, for two reasons. Firstly, the aquatic environment receives most of the pollutants intentionally released into the environment, through effluents from wastewater treatment plants, and secondly because many of the best documented examples of endocrine disruption in wildlife are of partially or completely aquatic species. These two reasons are probably not unconnected, of course. Hence, aquatic organisms can receive continuous exposure to endocrine‐disrupting chemicals throughout their lives, albeit usually to low concentrations of these chemicals. Analysis of effluents has identified many of the endocrine‐disrupting chemicals present, and shown that these are both natural and man‐made, and vary greatly in potency. Most attention has been directed to identifying the main estrogenic chemicals, because many of the effects reported in wildlife appear to be a consequence of ‘feminization’ of males. However, chemical analysis of effluents has also demonstrated that chemicals with other types of endocrine activity are present, such as androgens, anti‐androgens, progestagens, etc. The effects (if any, of course) of such chemicals on aquatic organisms are unknown, and largely uninvestigated, presently. Much of the biological research has centred on the effects of estrogenic chemicals, especially to fish. These effects, such as elevated vitellogenin concentrations and intersexuality, have to date been studied almost exclusively at the level of the individual, and hence whether endocrine‐disrupting chemicals cause population‐level consequences is largely unknown (the undeniable effects of TBT on molluscs, leading to local extinctions, being the exception). It is my opinion that rather too much of the recent research has not advanced our understanding of endocrine disruption a great deal, and we are probably not much further forward now than we were five years or so ago. It is surely time to tackle some of the outstanding, unresolved issues, such as the impact of endocrine disruption at the population level, and the issue of how organisms respond when exposed to complex mixtures of endocrine active chemicals. Such research will not be easy, and will require multidisciplinary teams, including people with expertise in areas not yet involved in the field of endocrine disruption, such as mathematical modellers. However, until such research is done, it will not be possible to decide how important an issue endocrine disruption is to wildlife, and how that importance compares to the other factors adversely affecting wildlife, such as habitat loss, climate change, and the introduction of exotic species and novel diseases. 相似文献
11.
《Marine pollution bulletin》2012,65(12):2782-2789
Plastics are known to sorb persistent organic pollutants from seawater. However, studies to quantify sorption rates have only considered the affinity of chemicals in isolation, unlike the conditions in the environment where contaminants are present as complex mixtures. Here we examine whether phenanthrene and 4,4′-DDT, in a mixture, compete for sorption sites onto PVC with no added additives (unplasticised PVC or uPVC) and Ultra-High Molecular Weight polyethylene. Interactions were investigated by exposing particles of uPVC and UHMW PE to mixtures of 3H and 14C radiolabelled Phe and DDT. Changes in sorption capacity were modelled by applying a Freundlich binding sorption isotherms. An Extended Langmuir Model and an Interaction Factor Model were also applied to predict equilibrium concentrations of pollutants onto plastic. This study showed that in a bi-solute system, DDT exhibited no significantly different sorption behaviour than in single solute systems. However, DDT did appear to interfere with the sorption of Phe onto plastic, indicating an antagonistic effect. 相似文献
12.
Gary Bickford John Toll Judi Hansen Elaine Baker Robert Keessen 《Marine pollution bulletin》1999,39(1-12):335-345
Sydney Water has completed a risk assessment to assess the risks to human health and aquatic organisms in creeks, rivers, estuaries and ocean waters affected by wet weather sewage overflows, stormwater and sewage treatment plant discharges. The risk assessment methodology consists of a comparison of measured and predicted concentrations of chemicals with toxicity reference values. Estimates of receiving water chemical concentrations were derived using data from a 10-year period so that the variable rainfall pattern was represented. Computer models were used to simulate and predict wet weather discharges during this ten year period. Risks were validated by bioassays and bioassessments. Risks to aquatic life from wet weather discharges were attributed to 14 chemicals at one or more of the sites and stormwater was the predominate source of the chemicals. There were no risks to people engaged in water based activities. Noncarcinogenic risks from fish ingestion are predicted at three sites. Predicted cancer risks for most individual chemicals were relatively small. Carcinogenic risks were typically associated with organochlorine compounds, polycyclic aromatic hydrocarbons, dichlorobenzene, and arsenic. The predicted cancer risks also appear to be largely the result of stormwater rather than sewage overflow inputs and largely due to historical contamination by organochlorine pesticides. It is expected the concentrations of these chemicals will decrease over time. 相似文献
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An ecotoxicological assessment is given to the state of small lakes in specially protected natural areas in Northwestern and Central European Russia, which suffer from aerotechnogenic acidification. The toxicity of water and bottom sediments is shown to increase with decreasing water pH. The most sensitive characteristics of aquatic organisms in different trophic groups are chosen, allowing the state of lakes to be monitored. 相似文献
15.
New Ways to Ecotoxicology: Quantitative Recording of Behaviour of Fish as Toxicity Endpoint The BehavioQuant system will be introduced which uses the integrative whole-organism response by automatized recording and quantifying the spontaneous behaviour of fish and other test organisms. While moving unrestricted within the test chamber, the movements of each single fish are recorded by video imaging, and their traces are digitized numerically by x-/y-coordinates. From the object traces several test parameters are calculated which give information about behavioural changes of the observed fishes. These various parameters are: the average swimming velocity (motility), the average swimming depth below surface, the inconstancy of motility, the frequency of turns, the standard frequency distributions of vertical and horizontal positions (can be used for quantification of a preference for dark or light habitats), and the distance behaviour. A continuously monitoring of up to 16 aquaria is possible. The statistic comparison between treated groups and control groups is done for each test parameter separately. The automatical evaluation of the continuous observation of surface waters results from a comparison of the actual behaviour data to the data of a reference period. Some examples for the applications of the BehavioQuant system will be demonstrated (effects of atrazine), and their results will be discussed. Behavioural changes of a single species can finally cause changes in biocenotic structures and functions. Therefore, it is necessary to include the results of quantitative behaviour measurements in ecotoxicological hazard assessment. 相似文献
16.
Chih Ted Yang 《Surveys in Geophysics》1977,3(1):39-68
Sediment movement in rivers is a complex phenomenon. The rate of sediment transport is related to many variables such as water discharge, average flow velocity, stream power, energy slope, shear stress, water depth, particle size, water temperature, and strength of turbulence. Different theories of sediment transport were developed by assuming different independent variables as the dominant variables. This survey provides a comprehensive review of the important theories of incipient motion and sediment transport. It discusses basic concepts and findings upon which knowledge of sediment transport is based and presents mathematical derivations and equations only in sufficient detail to illustrate some basic concepts. Data collected from natural rivers and laboratory flumes are used to compare the accuracy and applicability of different sediment transport equations. Finally, procedures are suggested for selecting sediment transport equations under different flow and sediment conditions. 相似文献
17.
T. I. Moiseenko 《Water Resources》2005,32(2):163-174
Comparative analysis of approaches and methods of biological assessment of water quality is presented. A method of ecotoxicological diagnostic of aquatic ecosystem health and water quality evaluation based on the physiological state of fish are substantiated. Characteristics of the main symptoms of diseases in fish inhabiting freshwater bodies and pathologic disturbances in their organs and tissues, caused by water bodies contamination with toxic substances, are presented. The method of ecotoxicological assessment of water quality is shown to be both highly informative and easy-to-use in practical monitoring.Translated from Vodnye Resursy, Vol. 32, No. 2, 2005, pp. 184–195.Original Russian Text Copyright © 2005 by Moiseenko. 相似文献
18.
With the Water Framework Directive (WFD) the European Commission (EC) is requested to define environmental quality standards for pollutants to protect aquatic life in surface waters. Quality standards have to be derived by a scientific risk assessment and should not be exceeded. The recommended quality standards are mainly based on long term toxicological tests with algae, crustaceans and fish. The lowest effect concentration is divided by an assessment factor between 10 and 1000, which considers the data quality and quantity. In this work funded by the German Länder Working Party on Water (Länderarbeitsgemeinschaft Wasser – LAWA) environmental quality standards for 40 considered relevant substances were derived for aquatic ecosystems. The data sheets cover the identification of the compounds, their behaviour in the environment (physical‐chemical properties, biotic and abiotic degradation, sorption, bioaccumulation), information about mode of action, uses, analytical determination and available quality criteria. Ecotoxicological effect concentrations for bacteria, algae, protozoa, aquatic plants, crustaceans, fish, amphibians, insects and molluscs are listed. For 17 of the 40 hazardous substances investigated, quality objectives above 1 μg/L were derived. For 12 substances the values were between 0.1 μg/L and 1 μg/L and for 5 substances lower than 0.1 μg/L. Incomplete ecotoxicological data sets of the remaining compounds do not allow the derivation of quality standards. Especially for drugs further ecotoxicological test results are needed. 相似文献
19.
In this study the stress–strain characteristics of sand-ground rubber mixtures are investigated in the sandlike zone,at different confining pressures,using hollow cylinder specimens subjected to torsional monotonic and cyclic loading.Under monotonic loading a mixture of sand-ground rubber with 10% and 25% rubber content show more contraction behaviour than that observed in a pure sand specimen.Phase transformation point in these mixtures are located on a larger shear strain.As expected,the shear strength of specimens decreases with increase of ground rubber content.However,with increasing of effective confining pressure,the loss in shear strength of the mixture is decreased.In addition,a mixture with 25% ground rubber shows a smaller loss in shear strength compared to a mixture with 10% ground rubber mixture.Under cyclic loading mixtures with 10% and 25% ground rubber have similar liquefaction resistance,especially at confining pressures of 110 k Pa and 260 k Pa.Therefore,by using of the mixture with 25% ground rubber,a larger volume of scrap tires could be recycled.The addition of ground rubber to sand would affect the shear strain variation and excess pore water pressure trends,and this effect was further intensified with increasing ground rubber percentage. 相似文献
20.
This study focuses on the prediction of the porosity of nonuniform sediment mixtures,considering the effects of particle packing.A random particle packing model has been developed for the porosity of bimodal mixtures by extending the existing random particle filling theory.Coefficients in the developed model are calibrated by fitting the model to measured data for a variety of bimodal mixtures,including spherical glass particles,rounded quarry grains,and natural sediments.The model coefficients ... 相似文献