Evaluation of farmers' attitude and perception toward production risk: Lessons from Khyber Pakhtunkhwa Province,Pakistan

The variations in farming risk are classified into three key categories: market liberalization, natural disasters such as floods or drought, and climate change. This study aims at filling the existing research gap by the assessment of risk attitude and risk perceptions toward various types of risks. Primary data of 600 respondents were collected through a structured questionnaire in four flood-prone districts namely Peshawar, Mardan, Charsadda, and Nowshera of Khyber Pakhtunkhwa (KP) province of Pakistan. Equally Likely Certainty Equivalent and risk matrix techniques were utilized in determining the risk attitude and risk perceptions among the farmers. A probit regression model was used to analyze the relationships among dependent and independent variables. Findings of the study show that majority of the farmers were risk-averse, and floods, high input prices, crop diseases, and excessive precipitation were the main risks perceived by the farmers. Results of the probit regression model indicated that age, education level, farm location, off-farm income, and access to market information were the main factors that affect the farmers' risk attitude and perceptions. The research offers essential findings that can be used by policy-makers in the farming sector and researchers to understand risk attitude and perceptions of farmers empirically.     

基于改进的“证据-权重法”评估污染土壤生态风险:以江苏靖江某电镀场地为例

污染场地土壤生态风险评估能够为准确制定土壤环境质量标准、污染土壤修复目标、土壤修复后效果评估及安全利用提供科学依据,是保障土壤健康和安全的重要手段。“证据-权重法”由于具有系统性、整体性和科学性的特点在风险评估中应用广泛。然而,当前“证据-权重法”大多依赖专家打分法进行权重设置,并且在实际操作中难以获得定量化的、信息全面的完整证据链,风险评估结果缺乏客观性和可比性。针对以上问题,本研究耦合美国EPA的四步法与层级法构建了“证据-权重法”污染场地土壤生态风险评估框架,统一了每个层级的评估方法与程序。采用多标准决策分析对权重进行定量化,通过预先设置证据链之间的层级来保证其相对独立性,基于基质试验和野外调查保证场地的针对性。最后,以靖江某电镀场地为案例进行实证研究,结果表明: 所构建的方法具有较强的可操作性,评估结果具有较高的客观性、科学性和准确性。     

城市化的生态风险及其管理

城市化体现在人口向城市聚集和城市景观扩张的同时,社会结构发生了极大变化,城市生产生活方式向更加广泛的地区扩散。然而,随着人口的过度密集和城市的日益扩张,交通拥堵、空气污染、废物堆积、流行病肆虐等"城市病"频发。城市通过大量汲取和消耗自然资源,向周围环境排放大量污染物,改变了区域生态系统的原有结构和功能,产生了严峻的生态风险,进而制约着城市生态系统的可持续发展。城市化的生态风险正逐步得到广泛关注,但对其具体的内涵和影响尚不明晰。归类描述了城市化过程中面临的各种生态风险,分析了导致生态风险的主要因素,阐述了辨识与评价生态风险的基本方法,提出了城市化生态风险的调控管理对策。     

区域生态风险管理研究进展

近20a来,随着生态风险评价研究的不断深化,区域生态风险评价的理论和方法日臻完善,与此紧密相关的生态风险管理日益受到了广泛关注.生态风险管理具有基于监控的反馈机制、风险受害者参与、程序灵活非线性化、关注成本效益等共同点.总结了国内外生态风险管理的研究进展,发现近年来生态风险管理的研究多是基于生态风险评价的结果,针对不同的风险类型和等级采取不同的管理措施.国内现有的研究对灾害风险管理的体系、机制建设较为成熟,但区域生态风险管理的机制研究尤其是预警和防范方面研究尚不成熟.基于此,构建了基于风险来临前、风险到来时和风险过后的区域生态风险管理的基本框架,研究结果对生态风险管理理论的构建和实践应用具有重要的意义.     

Are all distributions of risk with the same 95thpercentile equally acceptable?

When evaluating a probabilistic health risk assessment, say at a hazardous waste site, risk managers need a risk management policy that distinguishes an acceptable distribution of risks to individuals in a population from an unacceptable one. If a risk manager decides that the distribution of risk for the status quo is unacceptable, then a risk assessor needs a way to compute cleanup targets, i.e., the risk assessor needs a policy statement against which to estimate distributions of exposure point concentrations which, if engineered at a site, will achieve an acceptable distribution of risk. Some regulatory agencies base acceptability on whether the 95^th percentile of the risk distribution falls at or below a given value, without considering the behavior of the rest of the distribution. As regulatory agencies adopt risk management policies for use with probabilistic risk assessments, we recommend that they base their new policies on two simultaneously binding constraints‐one on an upper percentile and one on the arithmetic mean of the distribution of risk‐in addition to other non‐risk criteria.     

生态风险评价方法述评

生态风险是由环境的自然变化或人类活动引起的生态系统组成、结构的改变而导致系统功能损失的可能性。生态风险评价是定量预测各种风险源对生态系统产生风险的或然性以及评估该风险可接受程度的方法体系,因而是生态环境风险管理与决策的定量依据。在介绍了生态风险概念的基础上,按照风险源性质的分类标准将生态风险划分为化学污染类风险源、生态事件类风险源、复合类风险源3类,并分别论述了3类生态风险对应评价方法的特点与发展的方向。另外,针对生态风险评价研究的现状,讨论了我国生态风险研究的优先领域,包括建立急性、慢性毒理数据库,构建外来生物入侵风险评价标准等,同时,建议将综合概率统计学、复杂系统理论与遥感技术等手段引入生态风险评价方法中,以进一步提高风险评价结果在生态风险管理中的有效性。     

美国、加拿大环境和健康风险管理方法

对目前美国和加拿大多个部门使用的风险评价与风险管理方法进行了全面回顾和综合分析,论述各种不同方法的特征,深入探讨各种管理方法的基础、利弊、使用经验,辨识环境、人类健康和职业健康风险综合方法中应该包含的要素,阐述风险管理目标的确定方法,以期为中国的环境风险管理提供经验。     

A novel quantitative ecological and microbial risk assessment methodology: theory and practice

Abstract

The environment is a complex system where humans, materials (e.g. pollutants), and ecological (e.g. plants, animals, microbes) and meteorological conditions interact with each other. The impact of humans potentially causes significant damage to either the environment (e.g. oil spills may pollute coastal ecosystems) or turns against humans themselves by favoring the growth of unwanted species (e.g. poor sanitation increases microbial populations that cause the risk of large numbers of humans falling ill). Thus, this paper presents a flexible method for quantifying either ecological risks (i.e. the percentage likelihood of adverse effects on the ecosystem due to its exposure to stressors such as chemicals, fishing, etc.) or microbial risks (i.e. the likelihood of negative effects in humans due to their exposure to microbial pathogens). The method uses population modeling to simulate future changes in the numbers of key-species (e.g. fish, corals, sharks, parasites), in various scenarios including the impacts of humans, adverse weather and risk management. Finally, risk is calculated as the probability of the quasi-extinction or quasi-explosion of key-species over time, and then is categorized so that the risks involved may be better communicated to decision-makers. Using the method is illustrated in three different real cases in Brazil.     

区域生态风险评价的关键问题与展望

区域生态风险评价具有多风险因子、多风险受体、多评价终点、强调不确定性因素以及空间异质性的特点,它与传统的生态风险评价在风险源、胁迫因子和评价尺度上具有明显区别。尝试建立了一个基于陆地生态系统的区域生态风险评价框架,同时针对目前区域生态风险评价的研究现状,指出不确定性分析、尺度外推难、评价指标不统一、评价标准不统一、风险因子筛选及优先排序、区域内污染物复合、水生过渡到陆生生态系统风险评价、特殊的人为因素等是目前区域生态风险评价存在的关键问题及难点所在,并提出解决这些问题可能所需的工具、手段和理论方法突破。最后指出区域生态风险观测与数据采集加工、区域生态风险指标体系的统一与整合、区域生态风险评价方法论、区域生态风险的空间分布特征与表达以及区域生态风险评价反馈与管理机制5个方面是区域生态风险评价未来的研究重点。     

福建省台风灾害风险评估与区划

应用GIS技术,采用灾害风险指数法和加权综合评价法对福建省台风灾害风险进行评估及区划.结果表明:致灾因子危险性最大值分布在福建省东部沿海,承灾体的脆弱性最高值分布在东部的福州、厦门、泉州、漳州、莆田和宁德沿海以及西部的三明、龙岩、南平等地级市辖区,防灾减灾能力的分布比较分散,最高值主要分布在闽南的漳州、厦门、同安,闽中的泉州沿海以及莆田与福州沿海地区,另外还零散分布在福建西部的龙岩、三明、南平等地级市;综合考虑各因子指数的台风灾害风险度最高值(即风险度＞0.126)集中分布在福建省东部沿海的漳州、厦门、泉州、莆田、福州和宁德沿海地区.福建省台风灾害风险评估及区划可为福建省可持续发展和防灾减灾决策提供科学依据.     

Approaches for Integrated Risk Assessment

Recognizing the need to enhance the effectiveness and efficiency of risk assessments globally, the World Health Organization's International Programme on Chemical Safety, the U.S. Environmental Protection Agency, the European Commission, and the Organization for Economic Cooperation and Development developed a collaborative partnership to foster integration of assessment approaches used to evaluate human health and ecological risks. The objectives of this effort included: improving understanding of the benefits of integration, identifying obstacles to the integration process, and engaging key agencies, organizations, and scientific societies to promote integration. A framework with supporting documentation was developed to describe an approach for integration. Four case studies were constructed to illustrate how integrated risk assessments might be conducted for chemical and nonchemical stressors. The concepts and approaches developed in the project were evaluated in an international workshop. The goal of this effort was international acceptance of guidance for integrated risk assessment.     

Integrated Risk Assessment — Results from an International Workshop

The World Health Organization's International Programme on Chemical Safety and international partners have developed a framework for integrated assessment of human health and ecological risks and four case studies. An international workshop was convened to consider how ecological and health risk assessments might be integrated, the benefits of and obstacles to integration, and the research and mechanisms needed to facilitate implementation of integrated risk assessment. Using the case studies, workshop participants identified a number of opportunities to integrate the assessment process. Improved assessment quality, efficiency, and predictive capability were considered to be principal benefits of integration. Obstacles to acceptance and implementation of integrated risk assessment included the disciplinary and organizational barriers between ecological and health disciplines. A variety of mechanisms were offered to overcome these obstacles. Research recommendations included harmonization of exposure characterization and surveillance methods and models, development of common risk endpoints across taxa, improved understanding of mechanisms of effect at multiple scales of biological organization, and development of methods to facilitate comparison of risks among endpoints.     

Perspectives on environmental risk assessment

Risk is by no means a simple concept. Natural variability and definitional problems with the concept of probability complicate the measurement and use of risk as an analytical tool. Variability requires that risk assessment methods separate natural from total risk when attempting to estimate anthropogenic risk. Failure to do so results in the over estimation of anthropogenic risk and the eventual loss of credibility for risk assessment methodologies. The common frequentist approach to probability is not consistent with anything but a modelling approach to risk assessment. When combined with its ability to account for natural variability, incorporate laboratory-assay data and offer complete statistical and experimental control, modelling is a promising approach to risk assessment. Modelling, however, is not without its drawbacks. Initialization bias can result in the over, or under, estimation of both natural and anthropogenic risk. Furthermore, model estimates are time dependent. The convergence of natural and anthropogenic risk poses problems for modelling-based risk assessment and requires clear statements as to the importance of the time dimension in risk assessment. When combined, the drawbacks to modelling-based risk assessment argue that risk should never be stated as a scalar quantity. Instead, modelling-based risk assessment should provide estimates of the complete range of risk measures (total, natural, and anthropogenic) as well as indications of convergence time. Only then can the modelling-based approach be viewed as the most appropriate means of carrying out scientifically credible risk assessment.     

The Concept of Data Utility in Health Risk Assessment: A Multi-Disciplinary Perspective

Human and ecological health risk assessments and the decisions that stem from them require the acquisition and analysis of data. In agencies that are responsible for health risk decision-making, data (and/or opinions/judgments) are obtained from sources such as scientific literature, analytical and process measurements, expert elicitation, inspection findings, and public and private research institutions. Although the particulars of conducting health risk assessments of given disciplines may be dramatically different, a common concern is the subjective nature of judging data utility. Often risk assessors are limited to available data that may not be completely appropriate to address the question being asked. Data utility refers to the ability of available data to support a risk-based decision for a particular risk assessment. This article familiarizes the audience with the concept of data utility and is intended to raise the awareness of data collectors (e.g., researchers), risk assessors, and risk managers to data utility issues in health risk assessments so data collection and use will be improved. In order to emphasize the cross-cutting nature of data utility, the discussion has not been organized into a classical partitioning of risk assessment concerns as being either human health- or ecological health-oriented, as per the U.S. Environmental Protection Agency's Superfund Program.     

Finding fault with health risk assessment: A typology for risk assessment criticism

Although systematic, quantitative assessment of environmental health risks is a staple of regulatory decision-making, complaints regarding its perceived failures and shortcomings are an intrinsic feature of the policy landscape. In this article, we (a) catalog the classic criticisms of conventional health risk assessment, (b) create a typology that orders the critiques according to their focus on either input errors or output biases, and (c) identify selected allegations that fall within each category. We also note that the risk assessment–risk management paradigm has evolved over the past several decades, partially in accordance with the general direction and spirit of these classic critiques. The debate continues today along familiar lines invoking the traditional critiques and rebuttals outlined here.     

Perceptions of Mercury Risk and Its Management

Anthropogenic activities, such as coal burning for electricity generation, release mercury (Hg), a toxic, bioaccumulative pollutant with potential health impacts primarily borne by specific population groups such as women of child-bearing age and subsistence fishers. Current Hg risk communication efforts and much of the extant research on Hg risk perceptions focus on these groups most at-risk. Little is known about the perceptions of Hg risk among the general public, although their support is required for implementing Hg emissions mitigation policies. We report results from two surveys—one a U.S. nationally representative Internet survey and the other a mail survey of New England residents—on a range of perceptions of the general population regarding Hg risk and its management. Our analysis of quantitative and qualitative data from the surveys point toward some gaps in public understanding of Hg risk, on aspects such as sources of mercury release, agencies responsible for mercury information, and products that contain mercury. Our results suggest that agencies responsible for providing Hg information should go beyond fish advisories and enhance their efforts at wider dissemination of information on Hg risk and its management.     

Framework for the Integration of Health and Ecological Risk Assessment

The World Health Organization's International Programme on Chemical Safety (IPCS), the Organization for Economic Cooperation and Development (OECD), and the U.S. Environmental Protection Agency have developed a collaborative partnership to foster integration of assessment approaches for human health and ecological risks. This paper presents the framework developed by that group. Integration provides coherent expressions of assessment results, incorporates the interdependence of humans and the environment, uses sentinel organisms, and improves the efficiency and quality of assessments relative to independent human health and ecological risk assessments. The paper describes how integration can occur within each component of risk assessment, and communicates the benefits of integration at each point. The goal of this effort is to promote the use of this internationally accepted guidance as a basis for harmonization of risk assessment.     

The properties of global risk networks and corresponding risk management strategies

Global risks interconnect with one another and threaten our society as a highly interdependent system. However, knowledge on how risk materializations influence one another is limited. Thus, this study provides a network model to measure risk interdependence and presents recommendations on the integrative risk management framework.

This study develops a global risk network and calculates its key indicators of structural characteristics. Results show that global risks are closely interconnected and a particular triangle relationship exists among environmental, geopolitical, and societal risks. To improve the resilience of a risk system, the systematic important risks, which are “man-made environmental catastrophes” and “interstate conflict” in this study, should be monitored and controlled. Furthermore, we simplify the risk system by entirely managing risks in the same group based on our reclassification. Our method is considerably effective in detecting upcoming crisis and assists supervisors take timely action to prevent crisis.     

Practical Issues in the Use of Probabilistic Risk Assessment

Probabilistic risk assessment (PRA) represents an important step in the evolution of risk assessment methodology to assist decision-making at hazardous waste sites. Despite considerable progress in the development of PRA techniques, regulatory acceptance of PRA has been limited, in part because a number of practical issues in its use must yet be resolved. A recent workshop on PRA identified several areas to be addressed, including the need for: (1) better demonstration of the value of PRA in risk management; (2) PRA training and education opportunities; (3) the development of technical criteria for acceptability of a PRA; (4) policy decisions on acceptable risk distributions; (5) ways to deal with risk communication issues; and (6) a variety of technical issues, including ways to include estimates of variability and uncertainty associated with toxicity values. Solutions to many of these issues will require better dialog between risk assessors and risk managers than has existed in the past.