A Framework for Hazardous Materials Transport Risk Assessment

In this paper, we provide a framework for quantitative risk assessment in hazardous materials transport. We first outline a basic model where population centers are approximated by points on a plane with the assumption that in the case of an incident all residents in a population center will experience the same consequences. Different versions of this model have been used by other authors in the literature. This model may be valid if the hazardous materials route goes by small population centers. Then we extend this basic model to assess risks of shipping hazardous materials through large population centers that cannot be modeled as single points on a plane. In the extended model, large population centers are treated as two-dimensional objects on the plane, which allows for a more accurate treatment of consequences than the basic model. To the extent of our knowledge the extended model is novel. We provide numerical examples for both the basic and the extended models, and finish by discussing limitations of the suggested risk assessment framework.     

有害物品运输中“多点”-“多点”的风险公平性研究

在有害物品运输过程中,可能在多个起点和多个终点之间需要完成运输任务,因此网络中的某些路段可能被多次选择,从而导致这些路段上的人口与其他人口相比承担了较多的风险.为了实现有害物品运输过程中的风险公平性,本文给出了有害物品运输过程中区域风险差异和个体风险差异的定义,并建立了区域风险差异和个体风险差异的模型,然后,构建了一个考虑了人口风险、区域风险差异和个体风险差异的实现有害物品运输中"多点"-"多点"的风险公平性的模型,并给出了进行路径选择的启发式算法.     

Risk Management for Hazardous Materials Transportation: A Local Study in Lyons

A probabilistic risk assessment study has been undertaken in the French city of Lyons. The issue was to know whether it was justified to forbid hazardous material lorries in the city center and to divert them through the suburbs. Therefore, two routes, the City Center route and the Suburban route were compared. This paper describes the analysis and shows how the results were used in the decision-making process. It also lists the difficulties that are encountered when trying to incorporate formal risk analysis into actual decision-making processes. The risk analysis showed that rerouting is an effective option with respect to all criteria. The mathematical expectation of the number of deaths is divided by three, the reduction on the annual frequency of catastrophic accidents is even more important (about one order of magnitude for accidents involving more than 50 deaths). The spatial analysis proved that the risk was more evenly distributed along the Suburban route. However, the annual expected number of death is low: 0.5 in the worst case. So traditional decision-making approaches do not indicate the necessity of rerouting. Such a situation is believed to be typical for risk management of major hazards. In Lyons, the use of a very small risk aversion factor is sufficient to justify the rerouting option on a formal decision-aiding basis. This is rather unusual, but it is thought that the recognition of the importance of risk aversion by the decision-makers themselves is a very positive outcome from this study.     

The Tradeoffs Associated with Rerouting Highway Shipments of Hazardous Materials to Minimize Risk

Recent legislative and regulatory activities at the federal level have focused attention on the highway routing of hazardous materials. The question is whether routes that minimize the risk of release accidents (i.e., the expected number of persons impacted by releases of hazardous materials) should be used in lieu of the routes that have the lowest operating costs. This policy issue is addressed for interstate shipments by using a national network model to determine the practical route and minimum risk route between each of 100 different origin-destination pairs (state capitals). The resulting cost-risk tradeoffs are then used to estimate the average cost of rerouting per fatality averted, the value of which turns out to be within the range of values for a number of familiar existing regulations.     

Estimated Risk of Occupational Fatalities Associated with Hazardous Waste Site Remediation

This study presents a method to assess short term traumatic fatality risks for workers involved in hazardous waste site remediation to provide a quantitative, rather than qualitative, basis for evaluating occupational exposures in remediation feasibility studies. Occupational employment and fatality data for the years 1979–1981 and 1983 were compiled from Bureau of Labor Statistics data for 11 states. These data were analyzed for 17 occupations associated with three common remediation alternatives: excavation and landfill, capping, and capping plus slurry wall. The two occupations with the highest death rates, truck driver and laborer, contributed most to total exposure hours in each alternative. Weighted average death rates were produced for each alternative and multiplied by respective total person-years of exposure. The resultant expected number of fatalities was converted, using the Poisson distribution, to the risk of experiencing at least one fatality, as follows: 0.149 for excavation and landfill, 0.012 for capping, and 0.014 for capping plus slurry wall. These risks were discussed in light of the need to obtain more reliable and comprehensive data than are currently available on the occupational safety and health risks associated with hazardous waste site remediation and the need for a more scientific, quantitative approach to remediation decisions involving risks to workers.     

A New Approach to Hazardous Materials Transportation Risk Analysis: Decision Modeling to Identify Critical Variables

We take a novel approach to analyzing hazardous materials transportation risk in this research. Previous studies analyzed this risk from an operations research (OR) or quantitative risk assessment (QRA) perspective by minimizing or calculating risk along a transport route. Further, even though the majority of incidents occur when containers are unloaded, the research has not focused on transportation-related activities, including container loading and unloading. In this work, we developed a decision model of a hazardous materials release during unloading using actual data and an exploratory data modeling approach. Previous studies have had a theoretical perspective in terms of identifying and advancing the key variables related to this risk, and there has not been a focus on probability and statistics-based approaches for doing this. Our decision model empirically identifies the critical variables using an exploratory methodology for a large, highly categorical database involving latent class analysis (LCA), loglinear modeling, and Bayesian networking. Our model identified the most influential variables and countermeasures for two consequences of a hazmat incident, dollar loss and release quantity , and is one of the first models to do this. The most influential variables were found to be related to the failure of the container. In addition to analyzing hazmat risk, our methodology can be used to develop data-driven models for strategic decision making in other domains involving risk.     

Using Choice Experiments to Assess People''s Preferences for Railway Transports of Hazardous Materials

This article investigates whether the choice experiment approach can be used to assess people's preferences and the determinants of these preferences in order to estimate the costs and benefits of different configurations of the transport of hazardous materials by rail. Changes in the exposure to hazardous materials that people are subjected to are used rather than changes in accident risk. To the best knowledge of the author, this has not been done before in a study of people's preferences toward hazardous materials. A mail survey, carried out in two cities in Sweden, is used to obtain tentative estimates of the willingness to pay for a reduction in exposure as well as the willingness to accept an increase in exposure. Special attention is given to viability, since the complexity of the activity studied, transport of hazardous materials, and the method used pose particular challenges. The response rate and tests of validity and consistency indicate that this method can be applied. Moreover, the results suggest that studies of this kind may provide guidance on changes in the transport of hazardous materials, especially because policymakers may influence the attributes presented here. Referring to the exposure of hazardous materials highlights the importance of providing the respondents with adequate information regarding hazardous transports. An important finding is that the amount of background information may have some effect on the stated preferences.     

A GIS-Based Framework for Hazardous Materials Transport Risk Assessment

This article presents a methodology for assessment of the hazardous materials transport risk in a multicommodity, multiple origin-destination setting. The proposed risk assessment methodology was integrated with a Geographical Information System (GIS), which made large-scale implementation possible. A GIS-based model of the truck shipments of dangerous goods via the highway network of Quebec and Ontario was developed. Based on the origin and destination of each shipment, the risk associated with the routes that minimize (1) the transport distance, (2) the population exposure, (3) the expected number of people to be evacuated in case of an incident, and (4) the probability of an incident during transportation was evaluated. Using these assessments, a government agency can estimate the impact of alternative policies that could alter the carriers' route choices. A related issue is the spatial distribution of transport risk, because an unfair distribution is likely to cause public concern. Thus, an analysis of transport risk equity in the provinces of Quebec and Ontario is also provided.     

Risk Associated with Transportation of Spent Nuclear Fuel Under Demanding Security Constraints: The Colombian Experience

This note describes some of the safety and security concerns posed by the transportation of highly enriched uranium (HEU) from a nuclear research reactor located in Bogota (Colombia) to a port on the Colombian Caribbean coast. The operation was made at a moment of extremely high guerilla activity in Colombia, so that the decision-problem belongs in the extension of risk analysis known as threat analysis. By invoking a principle of dispreference for probability based on the concept of stochastic dominance, a qualitative risk comparison was made between the road and air alternatives.     

时变随机网络下有时间窗的有害物品运输路径选择研究

研究了时变随机网络下有害物品运输路径选择问题。首先定义了可行路径的具有随机性和时变性的选择向量,以期望值为目标,建立了多目标时变随机网络下有软、硬时间窗限制的有害物品运输路径选择模型。给出了时变随机网络下的有效路径的定义,并设计了多维时变随机动态标号,利用此标号设计了求解模型的多项式算法,通过此算法可以得到时变随机网络下有害物品运输路径的所有有效解。最后给出了一个应用算例。     

Monte Carlo Sensitivity Analysis of Unknown Parameters in Hazardous Materials Transportation Risk Assessment

The US Department of Transportation was interested in the risks associated with transporting Hydrazine in tanks with and without relief devices. Hydrazine is both highly toxic and flammable, as well as corrosive. Consequently, there was a conflict as to whether a relief device should be used or not. Data were not available on the impact of relief devices on release probabilities or the impact of Hydrazine on the likelihood of fires and explosions. In this paper, a Monte Carlo sensitivity analysis of the unknown parameters was used to assess the risks associated with highway transport of Hydrazine. To help determine whether or not relief devices should be used, fault trees and event trees were used to model the sequences of events that could lead to adverse consequences during transport of Hydrazine. The event probabilities in the event trees were derived as functions of the parameters whose effects were not known. The impacts of these parameters on the risk of toxic exposures, fires, and explosions were analyzed through a Monte Carlo sensitivity analysis and analyzed statistically through an analysis of variance. The analysis allowed the determination of which of the unknown parameters had a significant impact on the risks. It also provided the necessary support to a critical transportation decision even though the values of several key parameters were not known.     

Generalized Quantification of Risk Associated with Extreme Events1

In the partitioned multiobjective risk method (PMRM) the probability axis is typically partitioned into three regimes: high-exceedance low-consequence, intermediate-exceedance intermediate-consequence, and low-exceedance high-consequence (LE/HC). For each regime, the PMRM generates a conditional expected risk-function given that the damage lies within the regime. The theme of this paper is the conditional expected-risk function for the LE/HC regime. This function, denoted by f₄(.), captures the behavior of the “extreme events” of an underlying decision-making problem. The PMRM offers two advantages: (a) it isolates LE/HC events, allowing the decision-maker(s) to focus on the impacts of catastrophies; and (b) it generates more valuable information than that obtained from the common unconditional expected-risk function. Theoretical problems may arise from uncertainty about the behavior of the tail of the risk curve describing the underlying frequency of damages. When the number of physical observations in small (e.g., in flood frequency analysis), the analyst is forced to make assumptions about the density of damages. Each succeeding distributional assumption will generate a different value of f₄(.). An added dimension of difficulty is also created by the sensitivity of f₄(.) to the choice of the boundary of the LE/HC regime. This paper has two overall objectives: (a) to present distribution-free results concerning the magnitude of f₄(.); and (b) to use those results to obtain a distribution-free estimate of the sensitivity of f₄(.) to the choice of the boundary of the LE/HC regime. The above objectives are realized by extending, and further developing, existing inequalities for continuously distributed random variables.     

An Approach to Assessing the Impacts of Incident-Free Transportation of Radioactive Materials: I. Air Transportation

Annual radiation doses and risks to passengers and crew are calculated for shipments of radioactive materials in passenger aircraft under accident-free and incident-free conditions (i.e., under normal transportation conditions). The 1982 database developed by Sandia National Laboratories is used, and calculations are made using RADTRAN 4.0. This paper is one of two papers estimating radiological risk associated with incident-free transportation of radioactive materials.     

An Approach to Assessing the Impacts of Incident-Free Transportation of Radioactive Materials: II. Highway Transportation

Annual radiation doses and risks to the public living near, and traveling on, public highways, and occupational doses are calculated for highway shipments of radioactive materials under accident-free and incident-free conditions (i.e., under normal transportation conditions). The database developed by Sandia National Laboratories is used, and calculations are made using RADTRAN 4.0. This report is one of two reports estimating radiological risk associated with transportation of radioactive materials.     

企业国际化经营中关键风险的识别研究

风险识别是企业从事国际化经营时进行风险管理采取的首要步骤,也是进一步实施风险防范与规避的前提和基础.本文以中国企业的国际化经营为研究背景,在对国际风险分类与识别进行理论推导的基础上,通过实证研究,对企业在采取不同国际市场进入模式时所面临的各类风险加以识别,并对关键风险进行聚焦探析.     

Natural Disasters in the United States as Release Agents of Oil, Chemicals, or Radiological Materials Between 1980-1989: Analysis and Recommendations

Generally, hazards research and literature has treated natural and technological disasters as separate entities. This study attempts to determine how frequently interaction between these two types of disaster took place in the United States from 1980-1989. Data were collected by performing a literature review, contacting organizations and individuals active in hazards research and mitigation, and through a questionnaire sent to the emergency management agencies of all 50 states. The consensus derived from the data is that the number of incidents where natural and technological disasters interact is rising while preparations, which recognize the complications inherent in such combined events, remain cursory. There is a pressing need for states to record, and make available to managers, information regarding the number of combined natural/technological events affecting their areas. Only when such data are available will it be possible to make appropriate decisions regarding the best way to reduce the effects of a natural disaster causing a catastrophic release of hazardous materials.     

Not in My Town: Conflicting Views on the Siting of a Hazardous Waste Incinerator

In recent years a large number of conflicts associated with environmental risks have arisen in Hungary. The case study described here is related to the siting of a hazardous waste incinerator in Dorog. First, the history of the siting procedure is outlined in terms of the multiparty, multiattribute decision framework. Subsequently, the case reveals how stakeholder groups can be identified in the structure of decision-making, how they think about the object causing the conflict, about the conflict itself, and the possibilities of resolving it. In investigating the conflict, a combination of analytical tools were applied. The multiple-perspective model of Linstone and the argumentation analysis of Toulmin provided the frame for analyzing the information collected by interviews in the affected town, Dorog, and two other towns affected to different degrees in environmental problems.     

Estimates of the Health Risk Reductions Associated with Attainment of Alternative Particulate Matter Standards in Two U.S. Cities

As part of its periodic re-evaluation of particulate matter (PM) standards, the U.S. Environmental Protection Agency estimated the health risk reductions associated with attainment of alternative PM standards in two locations in the United States with relatively complete air quality data: Philadelphia and Los Angeles. PM standards at the time of the analysis were defined for particles of aerodynamic diameter less than or equal to 10 microm, denoted as PM-10. The risk analyses estimated the risk reductions that would be associated with changing from attainment of the PM-10 standards then in place to attainment of alternative standards using an indicator measuring fine particles, defined as those particles of aerodynamic diameter less than or equal to 2.5 microm and denoted as PM-2.5. Annual average PM-2.5 standards of 12.5, 15, and 20 microg/m3 were considered in various combinations with daily PM-2.5 standards of 50 and 65 microg/m3. Attainment of a standard or set of standards was simulated by a proportional rollback of "as is" daily PM concentrations to daily PM concentrations that would just meet the standard(s). The predicted reductions in the incidence of health effects varied from zero, for those alternative standards already being met, to substantial reductions of over 88% of all PM-associated incidence (e.g., in mortality associated with long-term exposures in Los Angeles, under attainment of an annual standard of 12.5 microg/m3). Sensitivity analyses and integrated uncertainty analyses assessed the multiple-source uncertainty surrounding estimates of risk reduction.     

Assessment and Management of Risk in the Transport of Dangerous Materials: The Case of Chlorine Transport in France

The purpose of this paper is to provide the main results of a study concerning the risk of chlorine transport by train in France. The specific problem of chlorine transport is presented in the framework of a general model for assessing the risk in the transport of dangerous materials. The probability of accidents followed with a chlorine release involving fatalities are put in perspective with other risks having potential health effects on the public. Two types of application of the model are envisaged in relation to the management of risk: the selection of protective measures through a cost-effectiveness approach and the use of the model for a better planning of decisions in an accident situation.     

Making Sense of Risk—A Sociological Perspective on the Management of Risk

This article describes how risk has been conceptualized in the business and organizational literature through four distinct transformations: from the techno‐scientific perspective to the cognitive, the social‐cultural, and, finally, to the constructionist perspective. Each domain conceptualizes risk in different ways, as organizations have found it difficult to understand and mitigate using the risk management tools available. Conceptualizing risk as sensemaking becomes relevant due to the complexity of information available to the risk manager, and, coupled with time constraints, this means that risk managers increasingly rely on making sense of possible threats rather than on the accuracy of the information received. This shift presents four contributions to the current literature. First, it suggests that the role of risk management is shifting from being technical in nature to being about risk sensemaking, where the manager engages with the social and physical environment with the aim of acquiring cues that could indicate how future events will unfold. Second, a sensemaking perspective implies a shift in the use of risk management systems from being “containers” of knowledge about past risk events to lending legitimacy to the plausibility of the success of future decisions. Third, the role of the risk manager in managing individual risks changes and becomes one of managing everything using the social networks and systems available as indicators of future risk events. Finally, the risk manager and the systems he or she relies upon are regarded as a source of risk in themselves as both act as gatekeepers for organizational risk decision making.