首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
The U.S. National Environmental Policy Act (NEPA) of 1969 heralded in an era of more robust attention to environmental impacts resulting from larger scale federal projects. The number of other countries that have adopted NEPA's framework is evidence of the appeal of this type of environmental legislation. Mandates to review environmental impacts, identify alternatives, and provide mitigation plans before commencement of the project are at the heart of NEPA. Such project reviews have resulted in the development of a vast number of reports and large volumes of project-specific data that potentially can be used to better understand the components and processes of the natural environment and provide guidance for improved and efficient environmental protection. However, the environmental assessment (EA) or the more robust and intensive environmental impact statement (EIS) that are required for most major projects more frequently than not are developed to satisfy the procedural aspects of the NEPA legislation while they fail to provide the needed guidance for improved decision-making. While NEPA legislation recommends monitoring of project activities, this activity is not mandated, and in those situations where it has been incorporated, the monitoring showed that the EIS was inaccurate in direction and/or magnitude of the impact. Many reviews of NEPA have suggested that monitoring all project phases, from the design through the decommissioning, should be incorporated. Information gathered though a well-developed monitoring program can be managed in databases and benefit not only the specific project but would provide guidance how to better design and implement future activities designed to protect and enhance the natural environment.  相似文献   

2.
3.
Environmental audits: Proposed terminology   总被引:1,自引:0,他引:1  
This paper presents a review of the fast developing subject of environmental auditing with the authors proposing a series of definitions. Of particular concern is a move towards the development of an accepted vocabulary for environmental impact assessment, even though the international dimension of the subject makes this a difficult task. Use of the word audit has become an accepted part of EIA vocabulary, however there are several types of audits being undertaken today. Presently, there are no commonly accepted definitions, consequently this paper will attempts to address this issue. Definitions for seven types of environmental audits are suggested, derived from the experience of the authors and from a review of the current literature. It is hoped that by the presentation of these definitions that such terms will be advocated for future EIA work, and thereby reducing confusion that otherwise may occur. The paper concludes with a brief review of the status of auditing.  相似文献   

4.
The development of chronological reference points to which present levels of inorganic pollutants can be compared is increasingly needed. This review is directed toward biological samples which are datable and have been characterized for one or more elements.  相似文献   

5.
6.
7.
8.
Antimony: global environmental contaminant   总被引:6,自引:0,他引:6  
  相似文献   

9.
Despite the value of aquatic insects in aquatic ecosystem biomonitoring, few studies within North America have addressed relationships between aquatic insect assemblages and landscape-level environmental variables. In this study, over 300,000 adult caddisfly specimens representing 224 species were collected and analyzed from samples of 225 Minnesota aquatic habitats within 58 watersheds. Detrended Correspondence Analysis and a UPGMA dendrogram of caddisfly relative abundance data determined that five regions of caddisfly biodiversity exist within the state. Species richness and diversity were significantly highest in the Lake Superior and Northern regions, lowest in the Northwestern and Southern regions, and intermediate in the Southeastern region. Canonical Correspondence Analysis determined that caddisfly species composition was related to temperature, percentage of disturbed habitat, and stream gradient. Although a strong correlation between temperature and percentage of disturbed habitat made determination of the relative importance of those variables difficult, it is likely that anthropogenic disturbance has decreased caddisfly biodiversity in at least the Northwestern and Southern regions. Now that regions of biodiversity have been established, future changes to the fauna can be evaluated with greater precision and confidence. This study represents the most comprehensive faunal analysis of an aquatic insect order within the Western Hemisphere.  相似文献   

10.
Patchy distributions: Optimising sample size   总被引:1,自引:0,他引:1  
A method for estimating sample size which does not require an a priori definition of desired precision, or the assumption that the population is normally distributed with constant variance, has recently been proposed. This paper discusses this method and presents five modifications which make the method easier to use and reduce the probability of estimating a larger sample size than is actually required. The method is extended and used to estimate the mean abundance of patchily distributed benthic organisms. The technique can be used to guide the design of any environmental sampling programme, be it physical, chemical or biological, where comparisons between times and/or locations are required. Trade-offs between numbers of replicates and numbers of levels/sites are discussed.  相似文献   

11.
12.
Non-regulated water contaminants: emerging research   总被引:4,自引:0,他引:4  
Those chemical pollutants that are regulated under various international, federal, and state programs represent but a small fraction of the universe of chemicals that occur in the environment as a result of both natural processes and human influence. Although the number of these targeted chemicals might be minuscule compared with the universe of both known and yet-to-be identified chemicals, an implicit assumption is that these selective lists of chemicals are responsible for the most significant share of risk with respect to environmental or economic impairment or to human health. This paper examines some of the less-discussed aspects of the background and assumptions that underlie society's relationship with chemical pollutants in water, particularly with respect to the need for a more holistic understanding of exposure and risk.  相似文献   

13.
14.
15.
The present study was undertaken to explore possibilities to judge survey quality on basis of a limited and restricted number of a-priori observations. Here, quality is defined as the ratio between survey and local variance (signal-to-noiseratio). The results indicate that the presented surveys do not permit such judgement. Furthermore, the discussion alsosuggests that the 5-fold local sampling strategies do not merit any sound judgement in about 10% of all cases.The results further imply that surveys will benefit from procedures, controls and approaches in sampling and sample handling, to assess both average, variance and the nature of the distribution of elemental concentrations in local sites. This reasoning is compatible with the idea of the site as a basic homogeneous survey unit, which is implicitly and conceptually underlying any survey performed.  相似文献   

16.
The analysis of toxaphene, a highly complex mixture of chlorinated bornanes, bornenes and camphenes, is a challenging problem, especially as individual congeners are present at trace levels in biota and other relevant samples. The complicated nomenclature of the compounds of interest is briefly discussed. Gas chromatographic techniques are the most important tools in toxaphene analysis because of their high resolution. The main focus of attention is devoted to important steps in the GC-based analytical procedure, such as sample preparation and injection, separation by single-column and multidimensional GC, both heart-cut and comprehensive, and detection by electron capture and, increasingly, MS-based detection/identification. The gradual shift from total toxaphene to individual compound analysis is discussed, and the growing interest in enantiomer-selective separations is highlighted. The problems encountered when selecting appropriate indicator compounds for rapid toxaphene screening are also addressed.  相似文献   

17.
18.
Air quality monitoring is currently ensured by captors measuring few physicochemical parameters, then they cannot evaluate unforeseen compounds and the interaction effects of pollutants. On the contrary, the use of bioindicators can answer these problems. Among them, plants are used in two ways:1) Passive bioindicators: trees, lichens and mosses are used to determine the distribution and even the contaminants long-term effects on vast zones and, possibly, the concentrations of pollutants to which they were exposed.2) Active bioindicators: tobacco and mosses make available the defective zones in plants and enable determination of deposition fluxes.Moreover, techniques based on biomarkers identification should increase the answer's sensitivity. However, the plants present the disadvantage of being unable to provide a response in a time lapse comparable with that of the on-line analysers. Lastly, the development of tools using animal cells should allow, in the near future, to measure the total polluting load under conditions close to those of the routine techniques. Then, the real impact of the contaminant on public health could be approached.  相似文献   

19.
20.
2002 has been a landmark year for children's environmental health, with several major international conferences dedicated to the issue and the publication of numerous reports and studies. In this article we review how and why children's health has emerged as a key environmental policy issue and what the analytical sciences can contribute.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号