Quantifying Flood Risks in the Netherlands

The Flood Risk in the Netherlands project (Dutch acronym: VNK2) is a large‐scale probabilistic risk assessment for all major levee systems in the Netherlands. This article provides an overview of the methods and techniques used in the VNK2 project. It also discusses two examples that illustrate the potential of quantitative flood risk assessments such as VNK2 to improve flood risk management processes: (i) informing political debates about the risks of flooding and the effectiveness of risk management actions, and (ii) (re)directing research efforts towards important sources of uncertainty.     

Landslide Risk Models for Decision Making

This contribution presents a quantitative procedure for landslide risk analysis and zoning considering hazard, exposure (or value of elements at risk), and vulnerability. The method provides the means to obtain landslide risk models (expressing expected damage due to landslides on material elements and economic activities in monetary terms, according to different scenarios and periods) useful to identify areas where mitigation efforts will be most cost effective. It allows identifying priority areas for the implementation of actions to reduce vulnerability (elements) or hazard (processes). The procedure proposed can also be used as a preventive tool, through its application to strategic environmental impact analysis (SEIA) of land-use plans. The underlying hypothesis is that reliable predictions about hazard and risk can be made using models based on a detailed analysis of past landslide occurrences in connection with conditioning factors and data on past damage. The results show that the approach proposed and the hypothesis formulated are essentially correct, providing estimates of the order of magnitude of expected losses for a given time period. Uncertainties, strengths, and shortcomings of the procedure and results obtained are discussed and potential lines of research to improve the models are indicated. Finally, comments and suggestions are provided to generalize this type of analysis.     

Discrimination, Vulnerability, and Justice in the Face of Risk

Recent research finds that perceived risk is closely associated with race and gender. In surveys of the American public a subset of white males stand out for their uniformly low perceptions of environmental health risks, while most nonwhite and nonmale respondents reveal higher perceived risk. Such findings have been attributed to the advantageous position of white males in American social life. This article explores the linked possibility that this demographic pattern is driven not simply by the social advantages or disadvantages embodied in race or gender, but by the subjective experience of vulnerability and by sociopolitical evaluations pertaining to environmental injustice. Indices of environmental injustice and social vulnerability were developed as part of a U.S. National Risk Survey (n= 1,192) in order to examine their effect on perceived risk. It was found that those who regarded themselves as vulnerable and supported belief statements consistent with the environmental justice thesis offered higher risk ratings across a range of hazards. Multivariate analysis indicates that our measures of vulnerability and environmental injustice predict perceived risk but do not account for all of the effects of race and gender. The article closes with a discussion of the implications of these findings for further work on vulnerability and risk, risk communication, and risk management practices generally.     

Interactive Hazards Education Program for Youth in a Low SES Community: A Quasi‐Experimental Pilot Study

A pilot study of an interactive hazards education program was carried out in Canberra (Australia), with direct input from youth participants. Effects were evaluated in relation to youths’ interest in disasters, motivation to prepare, risk awareness, knowledge indicators, perceived preparedness levels, planning and practice for emergencies, and fear and anxiety indicators. Parents also provided ratings, including of actual home‐based preparedness activities. Using a single group pretest‐posttest with benchmarking design, a sample of 20 youths and their parents from a low SES community participated. Findings indicated beneficial changes on a number of indicators. Preparedness indicators increased significantly from pre‐ to posttest on both youth (p < 0.01) and parent ratings (p < 0.01). Parent ratings reflected an increase of just under six home‐based preparedness activities. Youth knowledge about disaster mitigation also was seen to increase significantly (p < 0.001), increasing 39% from pretest levels. While personalized risk perceptions significantly increased (p < 0.01), anxiety and worry levels were seen either not to change (generalized anxiety, p > 0.05) or to reduce between pre‐ and posttest (hazards‐specific fears, worry, and distress, ps ranged from p < 0.05 to < 0.001). In terms of predictors of preparedness, a number of variables were found to predict posttest preparedness levels, including information searching done by participants between education sessions. These pilot findings are the first to reflect quasi‐experimental outcomes for a youth hazards education program carried out in a setting other than a school that focused on a sample of youth from a low SES community.     

Correlates of Hazard Education Programs for Youth

Virtually no research has examined the hypothesized benefits of hazard education programs for youth in helping to increase community resilience. This exploratory study examined the role of these programs in helping to increase child and family resilience to a range of future hazards. Various aspects of hazards programs were examined in relation to a wide range of child- and parent-reported hazard adjustments in a sample of 560 schoolchildren. Additional factors assessed included childrens' risk perceptions, knowledge of response-related protective activities, and hazard-related emotional factors. Overall, the results supported the role of hazards education programs in increasing hazard adjustments in the home. The findings also supported various aspects of education program involvement as being related to more realistic risk perceptions, increased knowledge, and increased interaction with caregivers. Analyses identified the following features of these programs as being particularly important: provision of specific knowledge (e.g., an emergency management perspective); multiple program involvement over time; and, importantly, promotion of increased interaction between children and parents. Overall, findings supported the idea that hazards education programs for youth provide one gateway through which communities can increase their resilience to the effects of a major hazardous event. Findings also provided an initial foundation for further research in this emerging area.     

Loss of Agro-Biodiversity, Uncertainty, and Perceived Control: A Comparative Risk Perception Study in Austria and China

The biogeographical centers of origin of important food crops-called Vavilov centers-are considered to be crucial sources of genetic diversity for present and future crop-breeding programs and thus for human food safety worldwide. Global environmental change and more intensified modes of crop production may cause genetic erosion (loss of traditional crop varieties and loss of crop wild relatives), especially in Vavilov centers. The present study focused on how the risk of genetic erosion (or loss of agro-biodiversity) is perceived in comparison to 16 other risk topics by experts and lay people in Austria and China. The most striking result was that genetic erosion was perceived to be an exceptionally unknown and uncertain risk topic, given that only genetically modified organisms (GMOs) were perceived as being even more uncertain. As a consequence of the high uncertainty, the idea of applying the precautionary principle to further prevent genetic erosion is discussed. An unprecedented finding-one that differs from Austrian participants-is that the Chinese have a higher perceived control over all risk topics. The increased perception of controllability in China is discussed in light of the theory of reflexive modernization. This theory strives to explain the increased critical attitude in Western countries such as Austria toward scientific innovations and toward the idea that everything can be calculated and mastered at will. By revealing different notions of risk perception, this research also provides additional scientific input to risk communication efforts for public education.     

Social Amplification of Risk in the Internet Environment

This article analyzes the dynamic process of risk amplification in the Internet environment with special emphasis on public concern for environmental risks from a high‐speed railway tunnel construction project in South Korea. Environmental organizations and activists serving as social stations collected information about the project and its ecological impact, and communicated this with the general public, social groups, and institutions. The Internet provides social stations and the public with an efficient means for interactive communication and an open space for active information sharing and public participation. For example, while the website of an organization such as an environmental activist group can initially trigger local interest, the Internet allows this information to be disseminated to a much wider audience in a manner unavailable to the traditional media. Interaction among social stations demonstrates an amplifying process of public attention to the risk. Analyses of the volume of readers’ comments to online newspaper articles and public opinions posted on message board of public and nonprofit organizations show the ripple effects of the amplification process as measured along temporal, geographical, and sectoral dimensions. Public attention is also influenced by the symbolic connotations of risk information. Interpretations of risk in religious, political, or legal terms intensify public concern for the environmental risk.     

Confidence deficits and reducibility: Toward a coherent conceptualization of uncertainty level

Outside of the field of risk analysis, an important theoretical conversation on the slippery concept of uncertainty has unfolded over the last 40 years within the adjacent field of environmental risk. This literature has become increasingly standardized behind the tripartite distinction between uncertainty location, the nature of uncertainty, and uncertainty level, popularized by the “W&H framework.” This article introduces risk theorists and practitioners to the conceptual literature on uncertainty with the goal of catalyzing further development and clarification of the uncertainty concept within the field of risk analysis. It presents two critiques of the W&H framework's dimension of uncertainty level—the dimension that attempts to define the characteristics separating greater uncertainties from lesser uncertainties. First, I argue the framework's conceptualization of uncertainty level lacks a clear and consistent epistemological position and fails to acknowledge or reconcile the tensions between Bayesian and frequentist perspectives present within the framework. This article reinterprets the dimension of uncertainty level from a Bayesian perspective, which understands uncertainty as a mental phenomenon arising from “confidence deficits” as opposed to the ill-defined notion of “knowledge deficits” present in the framework. And second, I elaborate the undertheorized concept of uncertainty “reducibility.” These critiques inform a clarified conceptualization of uncertainty level that can be integrated with risk analysis concepts and usefully applied by modelers and decisionmakers engaged in model-based decision support.     

The Risk Perception Paradox—Implications for Governance and Communication of Natural Hazards

This article reviews the main insights from selected literature on risk perception, particularly in connection with natural hazards. It includes numerous case studies on perception and social behavior dealing with floods, droughts, earthquakes, volcano eruptions, wild fires, and landslides. The review reveals that personal experience of a natural hazard and trust—or lack of trust—in authorities and experts have the most substantial impact on risk perception. Cultural and individual factors such as media coverage, age, gender, education, income, social status, and others do not play such an important role but act as mediators or amplifiers of the main causal connections between experience, trust, perception, and preparedness to take protective actions. When analyzing the factors of experience and trust on risk perception and on the likeliness of individuals to take preparedness action, the review found that a risk perception paradox exists in that it is assumed that high risk perception will lead to personal preparedness and, in the next step, to risk mitigation behavior. However, this is not necessarily true. In fact, the opposite can occur if individuals with high risk perception still choose not to personally prepare themselves in the face of a natural hazard. Therefore, based on the results of the review, this article offers three explanations suggesting why this paradox might occur. These findings have implications for future risk governance and communication as well as for the willingness of individuals to invest in risk preparedness or risk mitigation actions.     

Characterizing Risk for Cumulative Risk Assessments

In assessing environmental health risks, the risk characterization step synthesizes information gathered in evaluating exposures to stressors together with dose–response relationships, characteristics of the exposed population, and external environmental conditions. This article summarizes key steps of a cumulative risk assessment (CRA) followed by a discussion of considerations for characterizing cumulative risks. Cumulative risk characterizations differ considerably from single chemical‐ or single source‐based risk characterization. CRAs typically focus on a specific population instead of a pollutant or pollutant source and should include an evaluation of all relevant sources contributing to the exposures in the population and other factors that influence dose–response relationships. Second, CRAs may include influential environmental and population‐specific conditions, involving multiple chemical and nonchemical stressors. Third, a CRA could examine multiple health effects, reflecting joint toxicity and the potential for toxicological interactions. Fourth, the complexities often necessitate simplifying methods, including judgment‐based and semi‐quantitative indices that collapse disparate data into numerical scores. Fifth, because of the higher dimensionality and potentially large number of interactions, information needed to quantify risk is typically incomplete, necessitating an uncertainty analysis. Three approaches that could be used for characterizing risks in a CRA are presented: the multiroute hazard index, stressor grouping by exposure and toxicity, and indices for screening multiple factors and conditions. Other key roles of the risk characterization in CRAs are also described, mainly the translational aspect of including a characterization summary for lay readers (in addition to the technical analysis), and placing the results in the context of the likely risk‐based decisions.     

Tiered Chemical Testing: A Value of Information Approach

In December 2000 the EPA initiated the Voluntary Children's Chemical Evaluation Program (VCCEP) by asking manufacturers to voluntarily sponsor toxicological testing in a tiered process for 23 chemicals selected for the pilot phase. The tiered nature of the VCCEP pilot program creates the need for clearly defined criteria for determining when information is sufficient to assess the potential risks to children. This raises questions about how to determine the "adequacy" of the existing information and assess the need to undertake efforts to reduce uncertainty (through further testing). This article applies a value of information analysis approach to determine adequacy by modeling how toxicological and exposure data collected through the VCCEP may be used to inform risk management decisions. The analysis demonstrates the importance of information about the exposure level and control costs in making decisions regarding further toxicological testing. This article accounts for the cost of delaying control action and identifies the optimal testing strategy for a constrained decisionmaker who, absent applicable human data, cannot regulate without bioassay data on a specific chemical. It also quantifies the differences in optimal testing strategy for three decision criteria: maximizing societal net benefits, ensuring maximum exposure control while net benefits are positive (i.e., benefits outweigh costs), and controlling to the maximum extent technologically feasible while the lifetime risk of cancer exceeds a specific level of risk. Finally, this article shows the large differences that exist in net benefits between the three criteria for the range of exposure levels where the optimal actions differ.     

Source Credibility in Environmental Health – Risk Controversies: Application of Meyer''s Credibility Index

This article applies an existing five-item index for measuring source credibility in the context of environmental health-risk controversy. Survey data were gathered in five upstate New York communities facing environmental health-risk issues. Analysis of the five case studies and a combined dataset (N = 870) show that the credibility index was consistently reliable across all applications. Use of the resulting index is demonstrated through a comparison of the credibility of the New York State Department of Health (active in each case), the industries associated with each case, and the newspaper providing coverage of each case. The credibility index was used to predict risk judgments in a structural equation model. Overall, the analysis demonstrated that the credibility index performed consistently well across the five cases and illuminated important differences in each. As such, the index should be a useful addition to many environmental health and risk communication studies.     

The Distinction Between Risk and Hazard: Understanding and Use in Stakeholder Communication

A major issue in all risk communication efforts is the distinction between the terms “risk” and “hazard.” The potential to harm a target such as human health or the environment is normally defined as a hazard, whereas risk also encompasses the probability of exposure and the extent of damage. What can be observed again and again in risk communication processes are misunderstandings and communication gaps related to these crucial terms. We asked a sample of 53 experts from public authorities, business and industry, and environmental and consumer organizations in Germany to outline their understanding and use of these terms using both the methods of expert interviews and focus groups. The empirical study made clear that the terms risk and hazard are perceived and used very differently in risk communication depending on the perspective of the stakeholders. Several factors can be identified, such as responsibility for hazard avoidance, economic interest, or a watchdog role. Thus, communication gaps can be reduced to a four‐fold problem matrix comprising a semantic, conceptual, strategic, and control problem. The empirical study made clear that risks and hazards are perceived very differently depending on the stakeholders’ perspective. Their own worldviews played a major role in their specific use of the two terms hazards and risks in communication.     

On the Limits of the Precautionary Principle

The precautionary principle (PP) is an influential principle of risk management. It has been widely introduced into environmental legislation, and it plays an important role in most international environmental agreements. Yet, there is little consensus on precisely how to understand and formulate the principle. In this article I prove some impossibility results for two plausible formulations of the PP as a decision‐rule. These results illustrate the difficulty in making the PP consistent with the acceptance of any tradeoffs between catastrophic risks and more ordinary goods. How one interprets these results will, however, depend on one's views and commitments. For instance, those who are convinced that the conditions in the impossibility results are requirements of rationality may see these results as undermining the rationality of the PP. But others may simply take these results to identify a set of purported rationality conditions that defenders of the PP should not accept, or to illustrate types of situations in which the principle should not be applied.     

A Framework for Understanding Risk Perception,Explored from the Perspective of the Water Practitioner

Sustainable urban water systems are likely to be hybrids of centralized and decentralized infrastructure, managed as an integrated system in water‐sensitive cities. The technology for many of these systems is available. However, social and institutional barriers, which can be understood as deeply embedded risk perceptions, have impeded their implementation. Risk perceptions within the water sector are often unrecognized or unacknowledged, despite their role in risk management generally in informing value judgments and specifically in ranking risks to achieve management objectives. There has been very little examination of the role of these risk perceptions in advancing more sustainable water supply management through the adoption of alternative sources. To address this gap, this article presents a framework that can be used as a tool for understanding risk perceptions. The framework is built on the relational theory of risk and presents the range of human phenomena that might influence the perception of an “object at risk” in relation to a “risk object.” It has been synthesized from a critical review of theoretical, conceptual, and empirical studies of perception broadly and risk perception specifically, and interpreted in relation to water practitioners. For a water practitioner, the risk object might be an alternative water system, a component, a process, or a technology, and the object at risk could be public or environmental health, profitability, or professional reputation. This framework has two important functions: to allow practitioners to understand their own and others’ risk perceptions, which might differ, and to inform further empirical research.     

Identifying Childhood Age Groups for Exposure Assessments and Monitoring

The purpose of this article is to describe a standard set of age groups for exposure assessors to consider when assessing childhood exposure and potential dose to environmental contaminants. In addition, this article presents examples to show how the age groups can be applied in children's exposure assessments. A consistent set of childhood age groups, supported by an underlying scientific rationale, will improve the accuracy and comparability of exposure and risk assessments for children. The effort was undertaken in part to aid the U.S. Environmental Protection Agency (EPA) in implementing such regulatory initiatives as the 1997 Presidential Executive Order 13,045, which required all federal agencies to ensure that their standards take into account special risks to children. The standard age groups include: birth to <1 month; 1 to <3 months; 3 to <6 months; 6 to <12 months; 1 to <2 years; 2 to <3 years; 3 to <6 years; 6 to <11 years; 11 to <16 years; and 16 to <21 years. These age groups reflect a consideration of developmental changes in various behavioral, anatomical, and physiological characteristics that impact exposure and potential dose. It is expected that the availability of a standard set of early-life age groups will inform future analyses of exposure factors data as well as guide new research and data collection efforts to fill knowledge gaps.     

Ecological Risk Ranking: Development and Evaluation of a Method for Improving Public Participation in Environmental Decision Making

This article reports an extension of the Carnegie Mellon risk-ranking method to incorporate ecological risks and their attributes. On the basis of earlier risk-perception studies, we identified a set of 20 relevant attributes for describing health, safety, and environmental hazards in standardized risk summary sheets. In a series of three ranking sessions, 23 laypeople ranked 10 such hazards in a fictional Midwestern U.S. county using both holistic and multiattribute ranking procedures. Results were consistent with those from previous studies involving only health and safety hazards, providing additional evidence for the validity of the method and the replicability of the resulting rankings. Holistic and multiattribute risk rankings were reasonably consistent both for individuals and for groups. Participants reported that they were satisfied with the procedures and results, and indicated their support for using the method to advise real-world risk-management decisions. Agreement among participants increased over the course of the exercise, perhaps because the materials and deliberations helped participants to correct their misconceptions and clarify their values. Overall, health and safety attributes were judged more important than environmental attributes. However, the overlap between the importance rankings of these two sets of attributes suggests that some information about environmental impacts is important to participants' judgments in comparative risk-assessment tasks.     

The Role of Environmental Accidental Risk Assessment in the Process of Granting Development Consent

Environmental impact assessment (EIA) is a procedure that must be followed for certain types of development before they are granted development consent. The procedure requires the developer to compile an environmental impact report (EIR) describing the likely significant effects of the project on the environment. A regulatory requirement in Slovenia is that an accidental risk assessment for a new installation should be a part of an EIR. The article shows how risk assessment (RA) related to accidental release of methylene diphenyl diisocyanate (MDI) or a polyvalent alcohol mixture from a new planned unit of a chemical factory in the Alpine region of Slovenia was performed in the framework of an EIA for the purpose of obtaining a construction permit. Two accidental scenarios were considered: (a) a spill of 20 m³ of MDI or polyvalent alcohol mixture into the river Soča (the river runs close to the chemical factory) and (b) a fire in the warehouse storing the raw material, where emission of toxic gases HCN, NO_x, and CO is expected during combustion of MDI. One of the most important results of this case is the agreement among the developer, the competent authority, and a consultant in the field of EIA and RA to positively conclude the licensing process despite the absence of formal (regulatory) limit values for risk. It has been approved that transparent, reasonably uncertain, and semi-quantitative environmental risk assessment is an inevitable component of an EIA, and an essential factor in informed, licensing-related decision making.     

Risk Perception and Technological Development at a Societal Level

This article tests the hypothesis that the exposure to the threat to societies posed by the introduction of new technologies is associated with a normalization of risk perception. Data collected in 2000 by the International Social Survey Programme (ISSP) on environmental issues were used to explore this hypothesis. Representative samples from 25 countries were employed to assess the national levels of perceived threat to the environment associated with a series of technologies and activities. These values were correlated with economic indicators (mainly from the World Bank) of the diffusion of each of the technologies or activities in each country. Results indicate a negative association of risk perception with the level of technological prevalence (societal normalization effect) and a positive association with the rate of growth of the technology (societal sensitivity effect). These results indicate that the most acute levels of perceived environmental risk are found in those countries where the level of technological prevalence is low but where there has recently been substantial technological development. Environmental awareness is a mediator of the relationship between risk perception and the indices of technological diffusion. This result means that: (1) societal normalization of risk is not a direct consequence of prevalence of the technology, but is driven by awareness of technological development and that (2) societal sensitivity to risk is associated with lower levels of environmental awareness.