共查询到10条相似文献，搜索用时 78 毫秒
1.
饮水水源水质的人体健康安全是水源是否安全的首要问题。在调查锡矿矿坑水作为个旧市A镇及B矿段锡矿生活区饮用水源情况的基础上,应用国际辐射防护委员会和美国环保署推荐的风险评估模型,开展饮用水的人体健康风险评价。结果表明,水源中重金属致癌物质所引起的健康危害较高,风险值超过了国际辐射防护委员会推荐的最大可接受风险水平,其中以Cr6+和As的致癌风险最大,应优先控制;非致癌物质所引起的健康风险较小,风险值在10-8以下,远低于推荐的最大可接受风险水平。虽然水中重金属含量符合相关标准要求,但是长期饮用对人体存在健康风险。 相似文献
2.
饮水水源水质的人体健康安全是水源是否安全的首要问题。在调查锡矿矿坑水作为个旧市A镇及B矿段锡矿生活区饮用水源情况的基础上,应用国际辐射防护委员会和美国环保署推荐的风险评估模型,开展饮用水的人体健康风险评价。结果表明,水源中重金属致癌物质所引起的健康危害较高,风险值超过了国际辐射防护委员会推荐的最大可接受风险水平,其中以Cr6＋和As的致癌风险最大,应优先控制;非致癌物质所引起的健康风险较小,风险值在10-8以下,远低于推荐的最大可接受风险水平。虽然水中重金属含量符合相关标准要求,但是长期饮用对人体存在健康风险。 相似文献
3.
《International Geology Review》2012,54(11):1403-1431
A review of Geochemistry of Steppes and Deserts was published in an earlier issue of International Geology Review (v. 5, no. 6, p. 737). On the basis of this review, the Committee recomended that the eight papers constituting the major portion of the symposium be translated and published in International Geology Review. Therefore, /he first of these translations is published below. The remaining papers will be published in succeeding issues of IGR when possible and will be presented in the order as listed in the table of contents in the original symposium.--AGI Translation Office. 相似文献
4.
Tom Beer 《Natural Hazards》2007,42(3):469-480
The United Nations has declared 2008 to be the International Year of Planet Earth. It is being organised under the auspices of the International Union of Geological Sciences and UNESCO. Planning for the International Year of Planet Earth has consisted of establishing 10 major science themes including Hazards. The Hazards Theme is centred around the following key questions: (1) How have humans altered the geosphere, the biosphere and the landscape, thereby creating long-term changes detrimental to life and the environment and triggering certain hazards, while increasing societal vulnerability to geophysical (geological and hydrometeorological) hazards? (2) What technologies and methodologies are required to assess the vulnerability of people and places to hazards and how might these be used at a variety of spatial scales? (3) How do geophysical hazards compare relative to each other regarding current capabilities for monitoring, prediction and mitigation and what can be done in the short-term to improve these capabilities (4) What barriers exist to the utilisation of risk and vulnerability information by governments (and other entities) for risk and vulnerability reduction policies and planning (including mitigation) from each of the geophysical hazards? Following the 26 December 2004 Indian Ocean Tsunami and the UN World Conference on Disaster Reduction held in Kobe, Japan in January 2005, the International Council for Science (ICSU) decided to establish a major research programme and initiative on Natural and Human Induced Environmental Hazards and Disasters that will co-operate with the Hazards theme of the International Year and continue through to 2011. 相似文献
5.
6.
Contributions to a symposium of the IUGS Subcommission on Cambrian Stratigraphy at the International Geological Congress in Montreal in 1972 are the basis of this paper which is intended to give guidance to further work of what is now a Working Group on the Precambrian—Cambrian boundary of the International Geological Correlation Programme (UNESCO/IUGS). The proposed principles for the definition of the boundary are based on those accepted by the Commission on Stratigraphy, particularly on stratigraphic classification and on defining the Silurian—Devonian boundary. These matters are discussed by the authors in general terms and by W.B. Harland in terms of procedure. They are illustrated by examples of stratigraphic sequences across the boundary in Siberia given by A.Yu. Rozanov and discussed critically by V.E. Savitsky. New relevant discoveries of Early Cambrian faunas and their stratigraphic setting are reviewed by A. Boudda et al. P.E. Cloud's contribution, published elsewhere, and work in Australia are reviewed by the authors.The conclusions, based not only on the symposium material but also on current opinion, are that no single sequence which could serve as a reference standard for the Precambrian—Cambrian boundary has yet been identified but that many significant ones have been described which will be further examined. While the general limits for the choice of a boundary definition should lie between the horizons with fossils of Ediacaran type and those with diversified trilobite assemblages, a number of “Working Reference Points” exist in that interval which are correlatable horizons of faunal change. These cannot be defined simply as horizons of first appearance. 相似文献
7.
《Russian Geology and Geophysics》2007,48(8):668-674
In dividing supracrustal strata, formation and horizon have been and are basic stratigraphic units. Stratigraphic boundaries of a formation, a natural geologic body, are drawn mostly on the basis of its composition. Paleontological remains constrain the formation in time and spatially locate it in the Earth's crust. Boundaries between formations can be of three types: strictly stratigraphic, parastratigraphic, and allostratographic. The stratigraphic interval can range from a fraction of a horizon or chronozone to several stages. At the boundary between two systems the adjacent parts of the formation can relate to both systems. The main stratigraphic characteristics for recognizing horizons are paleontologic (biostratigraphic) features, revealed by zonal, paleoecosystemic (ecostratigraphic), bioeventual, and other methods to make a basis for their immanent signature. Horizon can be characterized by boundaries of only two types: strictly stratigraphic and allostratigraphic. The stratigraphic interval of a horizon can vary from a single chronozone to a stage. Boundaries of neighboring horizons at the contact between two stages or systems should coincide with the latter. The stratigraphic units of the International Stratigraphic Chart, in contrary to formation and horizon, are characterized by borders of only one type — strictly stratigraphic. 相似文献
8.
随着欠平衡作业和控制压力钻井应用的不断推广,为了更好的对这两项技术进行控制和管理,国际钻井承包商协会下属的UBO／MPD委员会对这两种技术按照风险等级、作业类别和流体系统进行了分类,共分为6级、3类、5种。首先介绍了这种分类体系,然后分别对欠平衡作业和控制压力钻井这两类作业方式的作业目的、流体类型选择、优缺点以及适用范围进行了分析评价。以期通过以上论述,为在具体施工作业中选择合适的钻井方式提供依据。 相似文献
9.
在全面收集地质和工程勘察资料基础上,系统梳理了成都市地下空间资源综合利用需要防范关注的7类地质问题以及需要统筹保护的4类地质资源。根据城市地下空间资源综合利用约束性地质要素（地质问题、地质资源）和地质结构在垂向上的差异,将成都市0~200 m地下空间划分为0~30 m、30~60 m、60~100 m、100~200 m 4个层位,在此基础上,提出了成都市地下空间分区、分层开发利用建议,编制了《支撑服务成都市地下空间资源综合利用地质环境图集》。图集范围覆盖成都市中心城区、高新西区、高新南区、国际生物城、天府新区成都直管区、天府空港新城、简州新城、淮州新城等重点地区,包括39张图件和1个地质调查报告。图集为成都市城市地下空间综合利用、城市空间优化拓展、城市功能品质提升以及国土空间开发、空间转型升级和城市集约、绿色、可持续发展提供了地质依据,对于全国其他城市开展同类图集编制具有示范和借鉴意义。 相似文献