前哨动物在环境污染物人体健康风险评价中的应用

前哨动物能够在污染物对生态系统或人体健康产生明显影响之前做出反应,所以利用前哨动物能够对环境污染的健康风险做早期预报,同时可提供环境中污染物种类、污染水平、生物可利用性、富集代谢等多方面的信息.虽然来自前哨动物的信息不能直接外推于人,但由于动物和人体结构和功能的相似性,这些信息可作为污染物对人体作用的早期警报.论文对作为前哨动物的某些鱼类、两栖动物和哺乳动物在环境污染物人体健康风险评价中的应用进行了简要概述,讨论了它们作为前哨动物各自的优缺点和适用范围,最后建议在国内大力开展前哨动物生态毒理学调查,以促进人体健康风险评价工作.     

Prehistoric Decline in Freshwater Mussels Coincident with the Advent of Maize Agriculture

Abstract:  During late prehistory, high population densities and intensive agricultural practices of Native American societies had profound effects on the pre-Columbian landscape. The degree to which Native American land use affected aquatic ecosystems is unknown. Freshwater mussels are particularly sensitive harbingers of modern-day ecosystem deterioration. We used data from prehistoric Native American shell middens to examine prehistoric trends in abundance of freshwater mussels of the genus Epioblasma in North America during the last 5000 years. The relative abundance of Epioblasma declined steadily during this period, a result that could be explained either by an increase in human impacts to streams or by long-term climatic changes unrelated to human activities. The rate of decline of Epioblasma increased significantly, however, after the advent of large-scale maize agriculture in the southeastern United States about 1000 years before the present. Our results suggest that human land-use activities in prehistory caused changes in freshwater mussel communities that were lower in magnitude but similar in direction to changes caused by recent activities.     

利用微量热法研究Cd2+和Cu2+对嗜热四膜虫(Tetrahymena thermophila)的毒性效应

利用微量热法研究Cd2 和Cu2 对嗜热四膜虫BF5(TetrahymenathermophilaBF5)生长代谢毒性效应 ,结果表明 :①低浓度的Cd2 (0～ 0 .4mgL-1)和Cu2 (0～ 10mgL-1)对四膜虫的生长有促进作用 ,而高浓度的Cd2 (0 .8～ 3.2mgL-1)和Cu2 (2 0～ 2 0 0mgL-1)则产生抑制作用 ;②Cd2 和Cu2 的半抑制浓度IC50 分别为 2 .0 4mg/L和15 5 .5mg/L ;③联合毒性为协同作用 ;④微量热法所得Cd2 和Cu2 单独作用时的IC10 分别为 0 .96mg/L和 19.9mg/L ,高于种类损伤法结果 ;⑤微量热法所得Cd2 和Cu2 单独作用时的IC10 均高于II级饮用水水质标准 .而Cd2 和Cu2 间的协同作用使Cd2 的IC10 降低为 0 .31mg/L ,高于水质标准 ;Cu2 的IC10 降低为 1.16mg/L ,与水质标准相近 .总之 ,微量热法不仅是一种快速评价污染物毒性效应的新方法 ,而且可用于相关的环境毒理学理论研究 .图 1表 5参 16     

谈人为因素对船舶防污染的影响及解决思路

简述了人为因素及其特点。分析了船舶溢油事故的成因。从人为因素的角度提出防治船舶污染的思路     

人类活动对北京东灵山地区景观格局影响分析

干扰改变景观格局,同时又受景观格局的影响,干扰是景观异质性的一个主要来源。应用ＩＬＷＩＳ地理信息系统,以１∶２００００植被图为基础,结合野外考察,分析了北京东灵山地区森林景观空间格局,采用缓冲区分析方法,研究了人类活动对该地区森林景观格局的影响。研究结果表明,在东灵山地区,人类活动的强弱与景观的破碎化表现出一定的相关性。人类作用强的地区斑块面积较小,作用弱的地区斑块面积较大,人类的活动对该地区的景观破碎化产生了明显的影响。随着距所选择的干扰区的远近,几个景观多样性指数没有表现出有规律的大小变化。虽然该地区人类活动有愈来愈强的趋势,但目前决定该地区景观空间格局的因子主要还是自然要素,人类活动虽然也对该区的景观格局产生了一定的影响,但还不是决定因素     

Active Amplification of the Terrestrial Albedo to Mitigate Climate Change: An Exploratory Study

To date, international efforts to mitigate climate change have focussed on reducing emissions of greenhouse gases in the energy, transportation and agriculture sectors, and on sequestering atmospheric carbon dioxide in forests. Here, the potential to complement these efforts by actions to enhance the reflectance of solar insolation by the human settlement and grassland components of the Earth's terrestrial surface is explored. Preliminary estimates derived using a static two dimensional radiative transfer model indicate that such efforts could amplify the overall planetary albedo enough to offset the current global annual average level of radiative forcing caused by anthropogenic greenhouse gases by as much as 30% or 0.76 Wm^{− 2}. Terrestrial albedo amplification may thus extend, by about 25 years, the time available to advance the development and use of low-emission energy conversion technologies which ultimately remain essential to mitigate long-term climate change. While a scoping analysis indicates the technical feasibility of sufficiently enhancing human settlement and grassland albedos to levels needed to achieve reductions in radiative forcing projected here, additional study is required on two fronts. Firstly, the modelled radiative forcing reductions are static estimates. As they would generate climate feedbacks, more detailed dynamic climate modelling would be needed to confirm the stationary value of the radiative forcing reduction that would result from land surface albedo amplification. Secondly, land surface albedo amplification schemes may have important economic and environmental impacts. Accurate ex ante impact assessments would be required to validate global implementation of related measures as a viable mitigation strategy.     

Striving for efficiency,harmony and vitality─A human ecological approach to urban sustainable development

Sustainability can only be assured with a human-ecological understanding of the complexinteractions among environmental,economic and social/cultural factors and with careful planningand management grounded in ecological principles. This paper will probe an integrative methodologyfor achieving environmentally sound, economically productive, and ecologically responsibledevelopment in urban and industrial areas of China through ecological regulation. The central objec-tive is to promote highly efficient resource use rather than high speed development,harmonious sys-tem′s relationship rather than inflexible compartmentalization, and robust and vital self-organizationrather than bureaucrstic control. This ecological order is to be regulated through technological inno-vation,institutional reform, and behavioral incentives that promote positive economic dcvelopmentwhile mitigating negative environmental impacts.     

Environmentally stratified sampling design for the development of Great Lakes environmental indicators

Understanding the relationship between human disturbance and ecological response is essential to the process of indicator development. For large-scale observational studies, sites should be selected across gradients of anthropogenic stress, but such gradients are often unknown for a population of sites prior to site selection. Stress data available from public sources can be used in a geographic information system (GIS) to partially characterize environmental conditions for large geographic areas without visiting the sites. We divided the U.S. Great Lakes coastal region into 762 units consisting of a shoreline reach and drainage-shed and then summarized over 200 environmental variables in seven categories for the units using a GIS. Redundancy within the categories of environmental variables was reduced using principal components analysis. Environmental strata were generated from cluster analysis using principal component scores as input. To protect against site selection bias, sites were selected in random order from clusters. The site selection process allowed us to exclude sites that were inaccessible and was shown to successfully distribute sites across the range of environmental variation in our GIS data. This design has broad applicability when the goal is to develop ecological indicators using observational data from large-scale surveys.     

Water Environmental Degradation of the Heihe River Basin in Arid Northwestern China

Water environmental degradation is a major issue in the Heihe River Basin belonging to the inland river basin of temperate arid zone in northwestern China. Mankind’s activities, such as dense population and heavy dependence on irrigated agriculture, place immense pressure on available and limited water resources during the last century, especially the recent five decades. An investigation on the water environmental degradation in the Heihe River Basin and analysis of its causation were conducted. The results indicated that water environmental changes in the whole basin were tremendous mostly in the middle reaches, which reflected in surface water runoff change, decline of groundwater table and degeneration of surface water and groundwater quality. Some new forms of management based on traditional and scientific knowledge must be introduced to solve problems of water environmental degradation in the Heihe River Basin.     

Between economics and ecology: some historical and philosophical considerations for modelers of natural capital

Natural capital models attempt to remediate the relationship between economics and ecology either by conjoining models and theories from each discipline or by finding a type of phenomena that can be meaningfully measured by both fields. The developmentof a widely accepted model which integrates economics and ecologyhas eluded researchers since the early 1970s. This paper offers an historical and philosophical perspective on some of the conceptual problems or obstacles that hinder the development ofnatural capital models. In particular, the disciplinary assumptions of economic science and ecological science are examined and it is argued that these assumptions are antithetical. Hence, the development of an effective and acceptednatural capital model will require that economics and ecology reconsider their self-conceptions as sciences. For the purposesof theoretical research and practical policy, the paper cautionsagainst confusing the issue of whether or not economic models accord with ecological models with the issue of whether or not economic activities accord with ecological realities.