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1.
The dinoflagellate cyst records in sediments from New Bedford Harbor and Apponagansett Bay demonstrate sensitivity to environmental change caused by human activity in the watersheds over the last 500 years. Changes in the species richness, as well as absolute and relative abundance of dinoflagellate cyst taxa reflect recent periods of development around the estuaries. Cyst taxa sensitive to these changes include Dubridinium spp., Polykrikos schwartzii, Lingulodinium machaerophorum, Operculodinium israelianum and Selenopemphix quanta. The greatest changes in the dinoflagellate cyst record occur during the 20th century, when New Bedford Harbor was exposed to both toxic pollution and heavy nutrient loading from point and non-point sources. Apponagansett Bay was not subject to industrial pollution and nutrient enrichment has been lower (from non-point sources). In Apponagansett Bay there is an increase in the dinoflagellate cyst species richness while species richness first increased, then declined in New Bedford Harbor. During the same period, the total dinoflagellate cyst concentration in New Bedford Harbor fluctuated over a wide range. The decline of species richness and the large fluctuations in the total cyst abundances signal the intensified anthropogenic disturbance in the watershed, notably a high degree of eutrophication and toxic pollution.  相似文献   

2.
In this study we present a novel comparison of three proxy indicators of paleoproductivity, pigments, biogenic silica (BSi), and cysts of autotrophic dinoflagellates measured in cored sediments from New Bedford Harbor, Massachusetts. In addition to detailed historical reports we use palynological signals of land clearance, changes in the ratio of centric and pennate diatoms, sedimentary organic carbon and stable carbon isotopes to constrain our interpretations. Our study spans the period from prior to European settlement to approximately 1977, during which watersheds were cleared, port development occurred and much of the coastal property became industrialized. The combined effects of nutrient loading from watershed clearance and urban sewage on the estuarine ecosystem shifted not only levels of primary production, but also the nature of the production. Our proxies show that when European colonists first arrived the estuarine production was benthic-dominated, but eventually became pelagic-dominated. Importance of water column production (by diatoms and dinoflagellates) rapidly increased as soil nitrogen was released following forest clearance. Stabilization in rates of forest clearance is reflected as a decline in production. However, population increases in the urbanizing watershed brought new sources of nutrients through direct sewage discharge, apparently again stimulating primary production. We assume that early 20th century changes in sewage discharge and introduction of heavy metals into Harbor waters caused a temporary reduction in primary production. The introduction of a new sewer outfall near the core site and changes in estuarine hydrography due to construction of a hurricane barrier across the mouth of the harbor are reflected by renewed water column production, but decreases in the population of diatoms and dinoflagellates. Fossil pigments suggest renewed water column production in the latest years recorded by our sediment core.  相似文献   

3.
Recent laboratory studies show that adding activated carbon to marine sediments reduces the bioavailability of persistent organic contaminants, such as polychlorinated biphenyls, to benthic organisms. The present work investigates how mixing activated carbon into cohesive sediment affects the stability of sediment obtained from the intertidal zone at the Hunters Point Naval Shipyard Superfund site in South Basin, San Francisco Bay, CA. Our results show for these sediments that mixing activated carbon into sediment does not significantly affect stability of surface sediments, as measured by sediment erosion rate and critical shear stress for incipient motion, thus supporting the potential field application of this technique for in situ stabilization of persistent organic contaminants. Hydrodynamic modeling was used to estimate the maximum bottom shear stress encountered during high-wind storm events at the estuarine inlet from which the sediments were obtained. Comparison of estimated bottom shear stresses with measured critical shear stresses shows that surface sediments will not erode under normal, non-storm conditions. Bottom shear stresses caused by large waves under infrequent high-wind storm conditions may erode surface sediments for short periods of time. We conclude from sediment stability tests and hydrodynamic modeling that mixing activated carbon amendment with cohesive sediment at selected locations within South Basin will not reduce surface sediment stability nor result in significant erosion of treated sediments.  相似文献   

4.
The main pollution problems of air, water and land are outlined. Although examples of intensive pollution ("hot‐spots") are probably less common than in the 19th century, current pollution is more widespread and the number of pollutants much greater. This makes the recognition of pollution more difficult and emphasizes the need for studies on the chronic effects of low concentrations of contaminants on individuals, populations, and communities. A study is also needed of synergistic effects resulting from the co‐action of contaminants which individually may be below threshold toxicity levels. Studies are also needed on the range of natural tolerance to a given toxin possessed by individuals and single species populations and on the environmental‐experimental aspects of selection pressures. The need for field experiments and a predictive model approach is stressed. The use of organisms as indicators and integrators of environmental pollutant burdens provides a quick and effective comparative method of mapping geographical and secular changes in contaminants.  相似文献   

5.
Based on extensive GC/MS screening analyses, the molecular diversity of petrochemical effluents discharged to a river in North Rhine-Westphalia was characterised. Within a wide spectrum of organic wastewater constituents, specific compounds that might act as source indicators have been determined. This differentiation was based on (i) the individual molecular structures, (ii) the quantitative appearance of organic compounds in treated effluents and (iii) the information on their general occurrence in the technosphere and hydrosphere. Principally, site-specific indicators have been distinguished from candidates to act as general petrochemical indicators. Further on, monitoring the environmental behaviour of target organic contaminants in an aquatic system shortly after their release into the river allowed a first evaluation of the impact of the petrogenic emission in terms of the quantity and spatial distribution.The identification of petrogenic contaminants was not restricted to constituents of the effluents only, but comprised the compounds circulating in the wastewater systems within a petrochemical plant. A number of environmentally relevant and structurally specific substances that are normally eliminated by wastewater treatment facilities were identified. Insufficient wastewater treatment, careless waste handling or accidents at industrial complexes are potential sources for a single release of the pollutants.This study demonstrates the relevance of source specific organic indicators to be an important tool for comprehensive assessment of the potential impact of petrochemical activities to the contamination of an aquatic environment.  相似文献   

6.
The structural diversity of the wastewater composition was described by the use of detailed non-target screening analyses of industrial effluents from chemical production sites. Determination of the indicative organic compounds acting as potential molecular indicators for industrial emissions from chemical production industries has been possible due to (i) detailed characterisation of industrial contaminants and identification of compounds with high source specificity, (ii) quantitative determination of the organic constituents in the industrial effluents and (iii) the review of their industrial applications. The determination of potential site-specific markers and industrial molecular indicators corresponding to certain production processes (production of starting materials for manufacturing paper and printing inks, powder coatings as well as epichlorohydrin production) was performed in this work.The results of this study allowed significant contributions to the chemical characterisation of industrial contaminants and isolation of indicators that can act as representatives of industrial effluents in the aquatic environment.  相似文献   

7.
《Planning》2019,(1)
Civil science and technology associations have been widely springing up everywhere in Britain, especially the new industrial towns in the eighteenth and nineteenth centuries. Associations held various academic activities, organized and funded scientific research, which played an important role in promoting the progress of science and technology and the development of industrial society. Based on case study on British Association for the Advancement of Science and Manchester Literary and Philosophical Society by academic circles at home and abroad, development situation of British science and technology associations in the middle and late 19~(th) century is summarized, and a series of activities of associations participating in industrial and agricultural development and environmental health reform are systematically sorted out, while the promoting role of science and technology associations in the social development of Britain in the 19~(th) century is explored.  相似文献   

8.
始建于1937年的天津第一热电厂位于天津市河东区六纬路,处于城市中心区,紧邻海河,是天津市最大的热电联产企业。自上世纪中叶以来,天津第一热电厂为天津市及周边省市的供电、供热做出了巨大贡献。天津第一热电厂记录了天津产业的发展历程,以其独特的文化价值和精神价值构成了天津城市历史的印记。因此,对天津第一热电厂产业建筑遗存改造再利用的研究是非常必要的。通过对第一热电厂的现状进行分析,结合德国鲁尔区、英国泰特艺术馆、纽约苏荷区等进行案例分析;阐明了适合于天津第一热电厂产业建筑遗存改造再利用的开发模式与类型,为今后天津第一热电厂和类似产业建筑遗存改造再利用提供参考。  相似文献   

9.
The Human Health Effect Programme in Greenland, a review   总被引:1,自引:0,他引:1  
The burden of persistent organic pollutants (POPs) in Arctic peoples has been monitored for some years. In 1997, the Alta Declaration extended the mandate of the Arctic Assessment and Monitoring Programme (AMAP) to cover assessment of the combined effects of environmental stressors. The AMAP Phase I assessment report (Assessment report: Arctic pollution issues. Arctic monitoring and assessment programme (AMAP), Oslo Norway, xii+859 pp. Vol xii + 859 pp. Oslo, Norway, 1998) gave an overview of the classical toxicology of contaminants. Only recently a programme for measuring the potential biological effects of these contaminants has been established: The AMAP Human Health Effect Monitoring Programme. Body burden data alone are not enough to assess the health risks associated with exposure to environmental contaminants in Arctic peoples. Furthermore, laboratory studies of the effects of single chemicals or chemical mixtures in laboratory animals and cell cultures cannot fully elucidate the human health risks. Integration of epidemiological health research and effect-biomarker studies on humans from exposed populations in the Arctic is needed in order to obtain information about the real health risks resulting from exposure to the accumulated mixtures of contaminants in the Arctic. The present text aims to give a short account of background literature on known and suspected effects of environmental chemicals on endocrine regulated processes with special emphasis on Arctic conditions. Following the evaluation of existing knowledge, a survey of the recently started Human Health Effect Biomarker Programme in Greenland is given.  相似文献   

10.
粤港澳大湾区9+2城市群是中国开放程度最高、经 济活力最强的区域之一,是以生态优先,绿色发展理念,建设 美丽湾区为引领,着力提升生态环境质量为目标的生态文明建 设区域。珠海处于粤港澳大湾区中最典型的珠江口地区,以该 区域城镇发展最快、规模最大的珠海西部河口湿地为研究对 象,对其植物景观群落的观赏性、耐盐性、抗风性、耐涝性、 耐旱性和耐污性等特质进行综合分析,结合对典型河口湿地景 观植物种类及立地条件开展调查,对河口湿地植物立地影响因 子进行了定量分析与评价。通过主成分分析法(PCA),综合 评估现阶段该区域湿地景观植物的适宜性、观赏性,并提出今 后适宜河口环境的景观植物种类,为河口湿地景观植物选择提 供技术支撑。  相似文献   

11.
Soils represent an important reservoir for persistent organic pollutants (POPs) in the terrestrial environment and thus the fate of contaminants deposited to the surface soils is important to understand. Since only a limited number of studies of the vertical distribution of POPs are available in the literature, the purpose of this study was to collect and analyze PCB concentrations in different layers of soil cores taken at agricultural and non-agricultural sites in Sweden. PCB concentrations at the agricultural site were nearly uniform on a dry weight basis throughout the depth considered (0-12 cm) while a distinct gradient with depth was observed at the five non-agricultural sites. On an organic carbon normalized basis, the concentration gradient was maintained at three of the non-agricultural sites while a more uniform distribution was observed at the other two sites. A statistically significant relationship between dry weight soil concentrations and organic carbon content was determined for all PCB congeners in the surface layers (0-1 cm) but not in the deeper layers (4-5 cm, 9-10 cm). These results were interpreted in relation to vertical soil transport processes and then the implications for environmental fate models including soil compartments were discussed.  相似文献   

12.
何伟骥 《建筑学报》2006,(12):14-16
20世纪晚期,资本主义经济体系经历了从福特主义转向弹性积累的过程,这一历史变迁,构成了后现代社会存在的基础。城市获得众多新特性,预示着后现代时期的来临。海市规划和首尔新国际机场,正是在这一背景下建构城市的两个尝试,透过后现代理论,我们将发现这两种城市的存在基础和建构逻辑。  相似文献   

13.
Environmental archives like peat deposits allow for the reconstruction of both naturally and anthropogenically forced changes in the biogeochemical cycle of Pb as well as the quantification of past and present atmospheric Pb pollution. However, records of atmospheric Pb deposition from pre-industrial times are lacking.In a publication by Weiss et al. [Weiss, D., Shotyk, W., Boyle, E.A., Kramers, J.D., Appleby, P.G., Cheburkin, A.K., Comparative study of the temporal evolution of atmospheric lead deposition in Scotland and eastern Canada using blanket peat bogs. Sci Total Environ 2002;292:7-18]. Pb isotopes data measured by Q-ICP-MS and TIMS, concentration and enrichment data was presented for sites in eastern Canada (PeW1) and northwestern Scotland (LL7c), dating to 1586 A.D and 715 A.D., respectively. Here these same cores are re-analysed for Pb isotopes by MC-ICP-MS thereby acquiring 204Pb data and improving on the original data in terms of resolution and temporal coverage. Significant differences were found between the Q-ICP-MS/TIMS and MC-ICP-MS measurements, particularly at PeW1. These discrepancies are attributed to the problematic presence of organic matter during sample preparation and analysis complicated by the heterogeneity of the organic compounds that survived sample preparation steps. The precision and accuracy of Pb isotopes in complex matrices like peat is not always well estimated by industrial standards like NIST-SRM 981 Pb.Lead pollution histories at each site were constructed using the MC-ICP-MS data. The entire LL7c record is likely subject to anthropogenic additions. Contributions from local mining were detected in Medieval times. Later, coal use and mining in Scotland, Wales and England became important. After industrialization (ca. 1885 A.D.) contributions from Broken Hill type ores and hence, leaded petrol, dominate atmospheric Pb signatures right up to modern times. At PeW1 anthropogenic impacts are first distinguishable in the late 17th century with the mining and use of local coal. After industrialization (ca. 1810 A.D.), coal and petrol are the main Pb sources. A comprehensive estimate of the natural atmospheric background 206Pb/207Pb signature in eastern Canadian aerosols is made with a value of ~ 1.19.  相似文献   

14.
Eutrophication and contamination with micropollutants have been major problems in water quality management. Both problems have been subjected to extensive research and modelling but traditionally are treated separately. Traditional simulation models for aquatic systems can be categorised as eutrophication models, contaminant fate models, food web models and food chain bioaccumulation models. Because they are single issue models, many interactions and feedbacks between the food web, nutrient and toxicant cycles are missed. Linking these models is essential to evaluate the fate and risks of contaminants in systems with changing nutrient loading, to assess the natural attenuation of contaminants or to understand the selfpurifying capacity of ecosystems. Combination of the single issue models requires inclusion of 'interaction processes' to account for the coupling between the (sub-) model types, such as organic carbon cycling. toxicity, transport and accumulation of organic contaminants in the food chain, and bottom up versus top down control of primary production and nutrient cycling. This review first provides a brief overview of traditional approaches in modelling eutrophication, contaminant fate, food web dynamics and food chain bioaccumulation. Second, five existing integrated eutrophication, fate and/or effects models are reviewed. Third, the gaps and limitations in modelling the four types of interaction processes are discussed. It is concluded that these models are invaluable tools to focus attention to feedback mechanisms that are often overlooked, to identify dominating processes in ecosystems, to formulate counterintuitive hypotheses on ecosystem functioning, or to assess short term risks of acutely toxic stressors. However, the potential of integrated models for long term simulations of contaminant exposure. food chain bioaccumulation and effects to higher trophic levels remains limited, mainly because of principal limitations in food web modelling. In contrast, the potential of integrated models for long term simulations of contaminant fate is better because the environmental distribution of contaminants is mainly determined by the major abiotic compartments and by biotic compartments at the base of the food chain.  相似文献   

15.
Among the present environmental issues drinking water quality and more specifically organic micropollutants receive not the highest priority. The long tradition of potable water quality assurance and the sophisticated evaluation methodologies provide a very useful approach which has great potential for wider application in environmental research and policy making.Water consumption patterns and the relative importance of the drinking water exposure route show that inorganic water contaminants generally contribute much more to the total daily intake than organic micropollutants. An exception is chloroform and probably the group of typical chlorination by-products. Among the carcinogenic organic pollutants in drinking water only chlorination by-products may potentially increase the health risk. Treatment should therefore be designed to reduce chemical oxidant application as much as possible.It is expected that in the beginning of next century organic micropollutants will receive much less attention and that the present focus on treatment by-products will shift to distribution problems. Within the total context of water quality monitoring microbiological tests will grow in relative importance and might once again dominate chemical analysis the next century.As disinfection is the central issue of the present water treatment practice the search for the ideal disinfection procedure will continue and might result in a further reduction in the use of chemical oxidants.  相似文献   

16.
The aim of this study was to compare the composition of bacterial and archaeal communities in contaminated sediments (Vidy Bay) with uncontaminated sediments (Ouchy area) of Lake Geneva using 16S rRNA clone libraries. Sediments of both sites were analysed for physicochemical characteristics including porewater composition, organic carbon, and heavy metals. Results show high concentrations of contaminants in sediments from Vidy. Particularly, high contents of fresh organic matter and nutrients led to intense mineralisation, which was dominated by sulphate-reduction and methanogenesis. The bacterial diversity in Vidy sediments was significantly different from the communities in the uncontaminated sediments. Phylogenetic analysis revealed a large proportion of Betaproteobacteria clones in Vidy sediments related to Dechloromonas sp., a group of dechlorinating and contaminant degrading bacteria. Deltaproteobacteria, including clones related to sulphate-reducing bacteria and Fe(III)-reducing bacteria (Geobacter sp.) were also more abundant in the contaminated sediments. The archaeal communities consisted essentially of methanogenic Euryarchaeota, mainly found in the contaminated sediments rich in organic matter. Multiple factor analysis revealed that the microbial community composition and the environmental variables were correlated at the two sites, which suggests that in addition to environmental parameters, pollution may be one of the factors affecting microbial community structure.  相似文献   

17.
During the twentieth century, two trajectories of urban development in the Arctic, Ralph Erskine's social and environmental project for a new town in Resolute, Canada, and the massive industrial city of Norilsk in the Soviet Union, converged on a set of ideas that define a unique typology of urban and architectural design in extreme northern climates. Best described as a microrayon—a Soviet planning concept that originated in the late 1950s—that has been adapted and transformed to accommodate environmental and social conditions in the extreme north, these two projects share many similarities despite their vastly different scales, and social, political, and economic contexts. Their evolution and development establishes an important precedent for urban design in extreme northern climates and future Arctic cities.  相似文献   

18.
Soil organic matter is a key component in ecosystems, as it is the essential part of a set of relevant processes and constitutes an important carbon pool contributing to Global Change. The design of environmental monitoring programmes should include indicators of the current status of ecosystems, alerting to incipient changes in them. In this context, a sampling scheme has been designed taking into account the main processes and soil uses affecting the dynamics of soil organic matter. Well-tested parameters were determined in order to assess which of them are most useful as indicators of soil organic matter evolution in arid soil, such as that in the "Cabo de Gata-Níjar" Natural Park (SE Spain). The parameters characterising the lability of the different fractions indicate changes in soil organic matter triggered by changes in soil use and soil dynamics. Changes in soil use, when drastic, are best reflected by those fractions comprising a high percentage of the total soil carbon, while the processes having slower dynamics are best demonstrated by the labile fractions. As a result of the sensitivity analysis of parameters versus changes, and taking into account the operational difficulties for determining them, the following indicators are proposed for a monitoring programme: total organic carbon, active fraction of the organic carbon and ratios of this fraction versus total organic carbon (%) (as given by the lability index proposed).  相似文献   

19.
In the early 20th century, zoning, restrictive covenants, deed restrictions, and federallysponsored real estate maps that directed bank loans operated at multiple levels to perpetuate spatial patterns that separated whites from Blacks, Asians, and other non-Anglo ethnics; homeowners from renters; and single-family dwellings from multi-family units. The obvious overtly racial biases of those systems are socially unacceptable today but their underlying purposes have since been augmented by new tools that mask further discrimination. This article presents a critical examination of the relationship between historic preservation, open space easements, and farmland preservation practices to reveal how these regulations support racial and social discrimination in American land-use practices. Existing literature presumes that history, nature, and farming, preserved by these practices are cultural, environmental, and public positives. An examination of the underlying forces shows how these goals are achieved by restrictive instruments that create exclusion and protect privilege by controlling development and establishing and maintaining social norms that exclude certain groups while welcoming others. Using documentary evidence, this paper establishes historic preservation’s origins as an instrument of racial and ethnic exclusion in Charleston, South Carolina and Philadelphia, Pennsylvania of the United States, and the subsequent evolution of historic districts into gentrified, white neighborhoods. Two case studies in the New York metropolitan area, chosen for their use of historic preservation with farmland preservation (Cranbury Township, Middlesex County, New Jersey), and historic preservation with open space easements (Town of Bedford, Westchester County, New York) as resistance to affordable residential development, demonstrate how enclaves of exclusion and privilege were created. This article further establishes how these tools commodify history and landscapes into transactional entities that attain value in today’s neoliberal wealth-focused environment.  相似文献   

20.
Mercury-contaminated effluent was discharged into Minamata Bay from a chemical plant over a 20-year period until 1965 (from 1958 to 1959, effluent was discharged into Minamata River), causing Minamata disease. In an effort to characterize the extent of the contamination in the Yatsushiro Sea, the vertical and horizontal distributions of mercury in sediment were investigated. Sediment was sampled at 62 locations in the southern part of the sea from 4 to 6 March 1996. In the lower layers of the long cores of sediment, the total amount of mercury was at a relatively uniform low concentration. We interpret these low values to represent the background concentration absent of anthropogenic influence. The background value thus estimated for the Yatsushiro Sea was 0.059 +/- 0.013 mg kg(-1) (mean +/- S.D., n = 51). The highest concentration in each sample ranged from 0.086 to 3.46 mg kg(-1) (mean, 0.57 mg kg(-1)). The higher values were obtained at stations near Minamata Bay and the Minamata River (the sources of the pollution). Concentrations decreased with distance from the source. An inspection of the vertical profiles of mercury concentration in cores suggested that the deposited mercury had not been fixed in sediment but had been transported, despite 30 years having past since the last discharge of contaminated effluent. At nine stations, extractable inorganic and organic mercury concentrations were determined differentially. Inorganic mercury is the predominant species in sediment and organic mercury comprising approximately 1% of the total.  相似文献   

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