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1.
转基因植物的生态风险评价   总被引:33,自引:0,他引:33       下载免费PDF全文
自从1983年第一株转基因植物诞生以来,至今各种类型的转基因植物进入大田试验的已不计其数,近10种转基因作物的产物已经商品化。与此同时,转基因植物向环境释放后可能带来的生态风险问题也越来越受到人们的重视。关于转基因植物的生态风险或对环境的危害,科学家提出了不同的概念和测试方法。生态毒理学的经验以及80年代发展起来的,为作环境决策用的生态风险评价的经验可以借鉴以作转基因植物生态风险的评价。本文介绍了转基因植物对农田生态系统和自然生态系统可能带来的危害以及从基因、基因组、个体、种群以至生态系统等各级水平上危害测试的方法。对风险的判断作了详细的论述,对风险的管理也作了概略的介绍,并对生态风险评价当前发展的水平进行了讨论。  相似文献   

2.
乐安江沉积物中金属污染的潜在生态风险评价   总被引:114,自引:3,他引:114  
选择污染严重的乐安江河流沉积物为对象,利用风险因子E和风险指数RI等定量诊断工具开展沉积物中重金属污染的潜在生态风险评价。根据风险指标体系和空间分异规律,将流域划分居不同特征的4种生态风险功能区。对比评价效果。潜在生态风险评价与地积累 情况大同小异,可以相互补充和借鉴。  相似文献   

3.
Problem formulation, risk analysis, and risk characterization are, respectively, the design, estimation, and interpretation stages of risk assessment. Models traditionally have been used to estimate exposure and effects; now opportunities are growing to use them to design and interpret risk assessments as well. This could raise the level of rigor, reproducibility, and transparency in the risk assessment process, and improve the way information and expertise gets integrated to advise risk managers. The importance of good design and interpretation to the success of risk assessment and risk management, and the role of modeling in that success, is becoming increasingly apparent, but to date models are used only to a fraction of their potential. We provide two examples of the use of models to design and interpret risk assessments. The first looks at the use of models to better characterize risks by modeling uncertainties and exposure from offsite sources, and the second to forecast future risks of a new technology. Following the examples, we discuss some important obstacles to translating new modeling opportunities into practice. These include practical limits on the abilities of organizations to assimilate new tools and methods, and conceptual limits in the way people think about models.  相似文献   

4.
按离路基不同距离采集土壤、麦苗和籽粒样品, 在测定样品重金属 (Pb、Cd、Zn、Cr和Cu) 的基础上, 开展了路旁土壤-小麦系统重金属分布、积累和污染状况分析, 并对膳食小麦 (Triticumaestivum) 引起的健康风险进行了评价。结果表明:1) 土壤-小麦系统重金属含量随着离开路基距离的增加呈先增加后减少的趋势, 土壤重金属含量>麦苗重金属含量>籽粒重金属含量。2) 麦苗和小麦籽粒对土壤重金属富集能力的大小顺序均为Cu>Cd>Zn>Pb>Cr, 麦苗对重金属的富集能力大于小麦籽粒。3) 膳食小麦所致的Cd个人健康风险较大。  相似文献   

5.
The U.S. Environmental Protection Agency determined that one of the major impediments to the advancement and application of ecological risk assessment is doubt concerning appropriate assessment endpoints. The Agency's Risk Assessment Forum determined that the best solution to this problem was to define a set of generic ecological assessment endpoints (GEAEs). They are assessment endpoints that are applicable to a wide range of ecological risk assessments; because they reflect the programmatic goals of the Agency, they are applicable to a wide array of environmental issues, and they may be estimated using existing assessment tools. They are not specifically defined for individual cases; some ad hoc elaboration by users is expected. The GEAEs are not exhaustive or mandatory. Although most of the Agency's ecological decisions have been based on organism-level effects, GEAEs are also defined for populations, ecosystems, and special places.  相似文献   

6.
Ecological risk assessments at military installations that are performed to support natural resources management objectives rely on information from the surrounding region. Stressors such as noise, ozone, and ozone precursors cross installation boundaries, and effects of urbanization and highway development are regional in scale. Ecological populations are not limited to one side of the installation boundary. Therefore, a framework for transboundary ecological risk assessment at military installations is under development. This article summarizes the problem formulation stage. Components include: (1) regional management goals such as installation Integrated Natural Resources Management Plans and land acquisition, (2) involvement of multiple stressors, and (3) large-scale assessment endpoint entities. Challenges of selecting measures of exposure include: quantifying exposure to aggregate stressors, describing land cover consistently in the region, describing rates of land-cover transition, scaling local measurements to a region, and aggregating or isolating exposures from within and outside of the installation. Measures of effect that are important to transboundary or regional ecological risk assessments at military installations are those that represent: effects at a distance from the stressor, large-scale effects, effects of habitat change or fragmentation, spatial extrapolations of localized effects, and integrated effects of multiple stressors. These factors are reflected in conceptual models.  相似文献   

7.
Toxicity tests are widely used to set “acceptable” levels of chemical exposure. Different organizations have identified a base set of tests specifying a mix of endpoints, durations, and species to be tested. A specific test and endpoint is chosen as the basis for calculation of human health risk values like reference doses (RfDs). This study empirically evaluates the data and choices made in setting acute and chronic RfDs for 352 conventional pesticides. The results suggest that for Acute, Acute-Female Specific, and Chronic RfDs one test is used far more than others. Ninety-six percent of the 116 Acute Female-Specific RfDs relied on a developmental toxicity test and 78% of Chronic RfDs used the chronic bioassay. Tests in rats were used far more often than other species in all RfD calculations. For all types of RfDs a total uncertainty factor of 100 was most common although values as low as 1 and as high as 3000 were seen. These results provide insights not only into the science policy frameworks used, but also into ways toxicity testing and risk assessment may be streamlined and made more efficient.  相似文献   

8.
Over the past 30 years, risk assessment has developed into a scientific discipline. It is critical that the next generation of risk assessors understand the history of our field, and recognize the numerous successes and failures that have taken place. This short Perspective identifies and describes specific books, monographs, and reports that are required reading for any nascent risk assessor.  相似文献   

9.
How should UNOS deal with the presence of scientific controversies on the risk factors for organ rejection when designing its allocation policies? The answer I defend in this paper is that the more undesirable the consequences of making a mistake in accepting a scientific hypothesis, the higher the degree of confirmation required for its acceptance. I argue that the application of this principle should lead to the rejection of the hypothesis that ‘less than perfect’ Human Leucocyte Antigen (HLA) matches are an important determinant of kidney graft survival. The scientific community has been divided all along on the significance of partial antigen matches. Yet reliance on partial matches has emerged as one of the primary factors leading blacks to spend a much longer time than whites on the waiting list for kidneys, thereby potentially impacting the justice of the kidney allocation policy. My case study illustrates one of the legitimate roles non‐epistemic values can play in science and calls into question the ideal of a value‐free science.  相似文献   

10.
本文提出一个危险度估测的对数正态概率模型,用此模型可建立某已知各浓度反应概率资料的反应经典曲线,估测不同浓度下总体的反应概率或个体被侵害的概率、某样本浓度的反应概率及某样本反应概率时的容许平均浓度.  相似文献   

11.
Data requirements are not harmonized globally for the regulation of food and feed derived from stacked genetically modified (GM) events, produced by combining individual GM events through conventional breeding. The data required by some regulatory agencies have increased despite the absence of substantiated adverse effects to animals or humans from the consumption of GM crops. Data from studies conducted over a 15‐year period for several stacked GM event maize (Zea mays L.) products (Bt11 ×  GA21, Bt11 ×  MIR604, MIR604 ×  GA21, Bt11 ×  MIR604 ×  GA21, Bt11 ×  MIR162 ×  GA21 and Bt11 ×  MIR604 ×  MIR162 ×  GA21), together with their component single events, are presented. These data provide evidence that no substantial changes in composition, protein expression or insert stability have occurred after combining the single events through conventional breeding. An alternative food and feed risk assessment strategy for stacked GM events is suggested based on a problem formulation approach that utilizes (i) the outcome of the single event risk assessments, and (ii) the potential for interactions in the stack, based on an understanding of the mode of action of the transgenes and their products.  相似文献   

12.
13.
Uncertainty may influence decision-making. A prerequisite for a decision to be well founded is thus that scientific experts inform decision-makers about all decision relevant uncertainty. A set of conditions is provided for adequate characterization of scientific uncertainty for the purposes of regulatory decision-making. These conditions require specification of (1) the character and degree of uncertainty about the assessment variables, (2) the possibility of reducing the uncertainty, and (3) the degree of agreement among experts. Furthermore, it is required that (4) the information covered by the previous conditions is presented in a clear and comprehensible way. The point of departure is that characterizing scientific uncertainty conceptually means specifying all potentially important possibilities that are consistent with the state of scientific knowledge. The conditions are intended to be applied to human health risk assessment of chemicals. However, the basic approach, to consider potentially important possibilities, should be useful also to environmental, and site-specific risk assessment.  相似文献   

14.
Objective: To explore the relationship between public trust in scientific experts on obesity and public attention to nutrition recommendations, to investigate trust as a predictor of weight‐related behaviors, and to identify the sociodemographic characteristics associated with high and low trust in scientific experts on obesity. Research Methods and Procedures: This analysis used survey data from two sources: 1) a 2005 Harvard School of Public Health Obesity Survey (N = 2033), and 2) the 2004 General Social Survey (N = 2812). Five outcome measures were used. Three were used to explore trust as a predictor of attention and weight‐related behaviors. Two were used to identify the sociodemographic predictors of trust. Logistic regression analysis was used to model the outcome variables. Results: Trust in scientific experts was the strongest predictor of public attention to nutritional recommendations from scientific experts, but it was not directly related to weight‐related behaviors. Public attention was significantly associated with two weight‐related behaviors: tracking fruit and vegetable intake and exercise. Women and more educated individuals had significantly higher odds of trusting scientific experts. Characteristics associated with distrust in scientific experts included Hispanic race and older age (over 50). Discussion: Public health experts should work toward building trust as an important step in stemming the obesity epidemic. Further, more research is necessary to better understand the factors driving trust in scientific experts on obesity. A deeper insight in this area will certainly be of great benefit to obesity‐related risk communication and potentially lead to positive behavior change.  相似文献   

15.
晋冀鲁豫接壤区生态环境现状评价   总被引:3,自引:0,他引:3  
刘全友  张遂业 《生态学报》1998,18(6):582-588
对“中国资源、生态环境预警研究”的有关方法,建立了晋冀鱼豫接壤区11个地、市的生态环境质量评价指标体系,并用层次分析法,对11个地市作出的生态环境质量进行了排序,以表征该区经济持续发展能力及其潜力。  相似文献   

16.
An ecological risk assessment was conducted at Yuma Proving Ground, Arizona, as a demonstration of the Military Ecological Risk Assessment Framework (MERAF). The focus of the assessment was a testing program at the Cibola Range, which involved an Apache Longbow helicopter firing Hellfire missiles at moving targets, that is, M60-A1 tanks. The problem formulation for the assessment included conceptual models for three component activities of the test, helicopter overflight, missile firing, and tracked vehicle movement, and two ecological endpoint entities, woody desert wash communities and desert mule deer (Odocoileus hemionus crooki) populations. An activity-specific risk assessment framework was available to provide guidance for assessing risks associated with aircraft overflights. Key environmental features of the assessment area include barren desert pavement and tree-lined desert washes. The primary stressors associated with helicopter overflights were sound and the view of the aircraft. The primary stressor associated with Hellfire missile firing was sound. The principal stressor associated with tracked vehicle movement was soil disturbance, and a resulting, secondary stressor was hydrological change. Water loss to desert washes and wash vegetation was expected to result from increased ponding, infiltration, and/or evaporation associated with disturbances to desert pavement. A plan for estimating integrated risks from the three military activities was included in the problem formulation.  相似文献   

17.
We discuss ethical aspects of risk‐taking with special focus on principlism and mid‐level moral principles. A new distinction between the strength of an obligation and the degree to which it is valid is proposed. We then use this distinction for arguing that, in cases where mid‐level moral principles come into conflict, the moral status of the act under consideration may be indeterminate, in a sense rendered precise in the paper. We apply this thought to issues related to pandemic influenza vaccines. The main conclusion of the paper is that on a principlist approach some acts may be neither right nor wrong (or neither permissible nor impermissible), and we claim that this has important implications for how we ought to make decisions under risk.  相似文献   

18.
《Chronobiology international》2013,30(5):1149-1158
In Germany, risk assessment of the working time arrangement is legally required, and within this context the authors assessed the usefulness of the fatigue and risk index (FRI) to predict any detrimental effects to health and safety. This assessment was made using data from two different surveys. Each contained records of working hours over a 4-wk period plus information on occupational accidents and health complaints. The independent variables drawn from the FRI parameters included the maxima, means, variances, and index factor scores. Phi-correlations between the FRI (dichotomized to the index of the reference system) and the incidence of an occupational accident were rather moderate, with a maximum correlation of .22 using the mean fatigue index (FI). Correlations between the two index factor scores and health complaints (sleep problems, stomach pain, eructation/heartburn) revealed the FI component, but not the risk index (RI) component, was related to those health complaints. Forward stepwise logistic regression analysis indicated the FI (but not the RI) predicted occupational accidents (FIfactor odds ratio [OR]?=?1.90, confidence interval [CI] 1.23–2.93). When using multiple regression analyses, the FI was able to predict sleep problems and other circadian related-problems, but the regression coefficients were moderate. In general, the results were not considered sufficient to justify a mandatory use of the FRI. (Author correspondence: )  相似文献   

19.
Background: Biomedical science is producing an avalanche of data about risk factors, often with a small predictive value, associated with a broad diversity of diseases. Prevention and screening are increasingly moving from public health into the clinic. Therefore, the question of which risk factors to investigate and disclose in the individual patient, becomes ethically increasingly urgent. In line with Wilson and Jungner's public health‐related 10 principles for screening, it seems crucial to distinguish important from unimportant health risks. Aim: to explore the ways in which clinicians distinguish important from unimportant health risks. Methods: We interviewed 36 respondents (gastroenterologists and gynaecologists/obstetrics) in 5 focus group interviews and 15 open in‐depth interviews on their interpretation of what makes a health risk important. Results: Physicians primarily interpreted importance as the severity of the possible harm, less often its probability. Possibilities of prevention or reassurance strongly influenced their judgment on importance. Discussion: It is not likely that interpreting ‘important’ as ‘severe’ will help in differentiating meaningful from meaningless risk knowledge. A more fundamental change in our ways of dealing with risk may be called for. We discuss existing literature on resilience as an alternative way to deal with risk. Balancing prevention and risk reduction with resilience could be a fruitful direction.  相似文献   

20.
The purpose of this paper is to show that a decontextualized approach to ethical issues is not just unhelpful for the decision making process of real, situated human beings, but dangerous. This is so, because by neglecting the context in which people make moral decisions we run the risk of reinforcing or furthering injustices against already disadvantaged groups. To show this, I evaluate three moral obligations that our ability to obtain genetic information has made salient: the duty to obtain genetic information about ourselves, the obligation to inform family members about genetic risks and the duty not to reproduce when we know that there is a high risk of transmitting a serious disease or defect. I will argue here that in ignoring the context in which these moral obligations are put into practice, and in particular the situation of women in our society, those who defend these moral duties might be furthering injustices against women.  相似文献   

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