bluuebunny/crossref_metadata_2025 huggingface dataset:
Public Concern About Industrial Hazards
Authors: Stallen Pieter Jan M. , Tomas Arend
Published: May 2006

In this paper we propose adopting a noncognitive perspective for the understanding of people's anxiety or, its opposite, feelings of security about living near hazardous industrial facilities. Results of our empirical investigations among residents of a heavily industrialized area indicate that at least four qualitatively different response patterns exist: the Secure, the Accepting, the Defensive, and the Vigilant response. In this order manifest anxiety increases, which increase is shown to be a function of the assessment of the threat, of the opportunities for personal control (specific), and of hope (generalized) to bring about a better environment by one's own action. As an application of the usefulness of this typology we discuss the various explanations for the often‐observed male/female difference in anxiety regarding industrial threat.
A Monte Carlo Analysis of Health Risks from PCB‐Contaminated Mineral Oil Transformer Fires
Authors: Eschenroeder Alan Q. , Faeder Edward J.
Published: May 2006

The objective of this study is the estimation of health hazards due to the inhalation of combustion products from accidental mineral oil transformer fires. Calculations of production, dispersion, and subsequent human intake of polychlorinated dibenzofurans (PCDFs) provide us with exposure estimates. PCDFs are believed to be the principal toxic products of the pyrolysis of polychlorinated biphenyls (PCBs) sometimes found as contaminants in transformer mineral oil. Cancer burdens and birth defect hazard indices are estimated from population data and exposure statistics. Monte Carlo‐derived variational factors emphasize the statistics of uncertainty in the estimates of risk parameters. Community health issues are addressed and risks are found to be insignificant.
Technical and Democratic Values in Risk Analysis1
Authors: Fiorino Daniel J.
Published: May 2006

So, we can argue that the lay public are not fools in their attitudes about risk. That nonexperts should show more concern over hazardous waste facilities in their neighborhoods than radon levels in their homes is not a sign of irrationality (because aggregate and individual risks are greater from the radon), but simply a sign that nonexperts are working from a different set of criteria. These criteria are incorporated in what I call the democratic model. The democratic model evaluates risk based on its social and political consequences, such as possible disruption in the social fabric or a loss of communality. Lay criteria for assessing the impact of risk decisions are not explicit, like the those of the risk analyst, but are embedded in cultural values. Similarly, lay evaluations of risk incorporate substantive and procedural democratic values, such as the acceptability of processes for making decisions, the ethics of the distribution of risk, and the capacity to control a source of risk in the community's interests. Finally, the democratic model relates judgments about risks to the competence (Can we trust them?) and the legitimacy (Should we trust them?) of the social institutions that impose and control those risks. The public's judgments about risk are not inferior, but different, and arguably richer than those of the experts.
The Role of Actuaries and Underwriters in Insuring Ambiguous Risks
Authors: Kunreuther Howard
Published: May 2006

Although there is a large body of literature on the unwillingness of the insurance industry to offer protection against risks such as environmental pollution, there has been only limited analysis regarding two key actors in the decision process—actuaries and underwriters. However, if actuaries and underwriters feel that a particular type of risk is uninsurable, then it is unlikely to be offered. This paper investigates how ambiguities associated with a risk affect actuary and underwriter decision processes, the paper contends that the decision of the insurance industry to not provide protection against environmental pollution liability is due to ambiguity of the risk. Empirical evidence from controlled laboratory experiments with actuaries and a model of choice in underwriter decision processes support this point.
Are Large Differences in “Lifesaving” Costs Justified? A Psychometric Study of the Relative Value Placed on Preventing Deaths
Authors: Mendeloff John M. , Kaplan Robert M.
Published: May 2006

Government actions to reduce risks to health have varied greatly in their cost per death prevented, frequently by 10‐fold or even 100‐fold. This research asks whether disparities of this magnitude are justified by citizens’preferences abut the relative value of reducing deaths from different hazards. Four samples were asked to rank the relative priority of preventing deaths through 8 realistic programs, each addressed to a different hazard, and then to rate how large the differences in spending should be. Subjects were not asked to give absolute values on preventing deaths and were asked only for their relative valuation of the benefits of preventing a death, not to weigh the benefits and costs or to determine an optimal spending level. We found that in all samples the median respondent valued his top‐rated program 5 to 6 times more than his bottom‐rated program. However, because individuals disagreed upon the relative priority for different programs, the aggregated rankings barely showed more than a 2‐fold difference in the amounts that should be spent. Thus, for the important programs considered by these samples, a large variation in spending does not appear to be justified on the basis of differentials in the values placed on preventing different types of deaths. A more deliberative methodology like the one used here appears fruitful for providing insights to policymakers about preferences in this sensitive area.
Calculating the Hazard Function and Probability of Tumor for Cancer Risk Assessment When the Parameters Are Time‐Dependent
Authors: Quinn Dennis W.
Published: May 2006

The probability of tumor and hazard function are calculated in a stochastic two‐stage model for carcinogenesis when the parameters of the model are time‐dependent. The method used is called the method of characteristics.
Bayesian Methods for Modeling Recovery Times with an Application to the Loss of Off‐Site Power at Nuclear Power Plants
Authors: Iman Ronald L. , Hora Stephen C.
Published: May 2006

Bayesian methods can be very useful in modeling applications used in risk assessments. For example, a Bayesian analysis can be used to provide a probabilistic comparison of different probability models relative to a set of data, as well as to provide uncertainty bounds on the predictions from the various models. For more complex models or composite models, the Bayesian methods easily adapt to include the uncertainty on the weights associated with each of the models that comprise the composite model. Industry data representing the time to recovery of loss of off‐site power at nuclear power plants are used within this paper to demonstrate these aspects of Bayesian analysis.

SUMMARY AND CONCLUSIONS

The Bayesian based method presented in Section 3 for the calculation of posterior odds provides the analyst with a way of quantifying the adequacy of different probability models for a set of data, and thus replaces the subjectivity with an objective criterion. The methods presented in Sections 4 and 5 provide a basis for constructing uncertainty bounds for recovery/probability curves. These uncertainty bounds are useful in risk assessments. The bounds capture parametric uncertainties and uncertainties about relative frequencies of various initiators of events. The methods presented in Section 6 demonstrate how to modify a model to incorporate specific information about the site under study.
A Perspective on Dioxin Emissions from Municipal Solid Waste Incinerators
Authors: Travis Curtis C. , Hattemer‐Frey Holly A.
Published: May 2006

This paper discusses the following key issues concerning human exposure to dioxins and furans emitted from typical, modern MSW incinerators: (1) Are MSW incinerators the major source of PCDD/PCDF input into the environment? (2) Are environmental concentrations around MSW incinerators substantially elevated relative to background levels? And (3) are MSW incinerators the major source of human exposure to PCDDs and PCDFs? Current scientific evidence indicates that (1) combustion sources in general (including steel mills, copper smelting plants, motor vehicles, pulp and paper mills, and MSW incinerators) are major sources of PCDD/PCDF input in the environment; (2) environmental concentrations of PCDDs and PCDFs around operating MSW incinerators are not substantially elevated; and (3) 99% of human exposure to PCDDs and PCDFs is from background contamination, even for individuals living near a modern MSW incinerator.
Additive and Multiplicative Models and Multistage Carcinogenesis Theory
Authors: Brown Charles C. , Chu Kenneth C.
Published: May 2006

In light of the Armitage‐Doll multistage carcinogenesis theory, this paper examines the assumption that an additive relative risk relationship is indicative of two carcinogens that affect the same stage in the cancer process. We present formulas to compute excess cancer risks for a variety of patterns for limited exposure durations to two carcinogens that affect the first and penultimate stages; and using an index of synergy proposed by Thomas (1982), we find a number of these patterns to produce additive, or nearly additive, relative risk relationships. The consistent feature of these patterns is that the two exposure periods are of short duration and occur close together.
Setting a Context for Explaining Risk
Authors: Hance Billie Jo , Chess Caron , Sandman Peter M.
Published: May 2006

Agency representatives often believe that if they could only find ways to explain risk data more clearly, communities would accept risk that scientists see as minimal, and take seriously risks scientists see as serious. While explaining the data effectively is important, agencies and industries need to place a greater priority on understanding community concerns, involving communities in risk decisions, and developing trust and credibility.
Estimating the Risks of Smoking, Air Pollution, and Passive Smoke on Acute Respiratory Conditions
Authors: Ostro Bart David
Published: May 2006

Five years of the annual Health Interview Survey, conducted by the National Center for Health Statistics, are used to estimate the effects of air pollution, smoking, and environmental tobacco smoke on respiratory restrictions in activity for adults, and bed disability for children. After adjusting for several socioeconomic factors, the multiple regression estimates indicate that an independent and statistically significant association exists between these three forms of air pollution and respiratory morbidity. The comparative risks of these exposures are computed and the plausibility of the relative risks is examined by comparing the equivalent doses with actual measurements of exposure taken in the homes of smokers. The results indicate that: (1) smokers will have a 55–75% excess in days with respiratory conditions severe enough to cause reductions in normal activity; (2) a 1 μg increase in fine particulate matter air pollution is associated with a 3% excess in acute respiratory disease; and (3) a pack‐a‐day smoker will increase respiratory restricted days for a nonsmoking spouse by 20% and increase the number of bed disability days for young children living in the household by 20%. The results also indicate that the estimates of the effects of secondhand smoking on children are improved when the mother's work status is known and incorporated into the exposure estimate.
Conventional Wisdom on Risk Communication and Evidence from a Field Experiment
Authors: Johnson F. Reed , Fisher Ann
Published: May 2006

A recent comprehensive review of the literature identified a number of facts and principles governing risk communication. This paper evaluates several of these propositions using recent evidence from a field experiment in communicating the risks from radon in homes. At this point in the research, data relates primarily to the response of risk perceptions to different information treatments and different personal characteristics. The effect of various causal factors is sensitive to the particular test of risk perception applied. No information treatment was clearly superior for all tasks. An important implication of these findings is that risk communicators must determine what specific task or tasks the information program should enable people to do.
Accidents and Nonrandom Error Propagation
Authors: Turner Barry A.
Published: May 2006

The use of random elements in accident analyses is practical in that it avoids the need to enumerate all possible failure paths and allows the application of probability analyses to some elements of a complex system. Sometimes, however, the concept of randomness is used only as a residual category to label unexplained features of accident analysis. When common cause failures or system interactions are involved, such an approach can be misleading. Analyses focusing upon nonrandom elements can thus be important in understanding failures of both technical and organizational systems, and some of the problems of such an approach are explored. A detailed analysis of a fatal fire in a railway sleeping car at Taunton, England, in 1978, demonstrates how initial errors can interact with an existing sociotechnical structure to produce new orderly patterns as an accident develops. A simple model to understand this nonrandom error propagation requires a description of the initial system structure in social and technical terms, specifying features such as the task and the sentient boundaries of subsystems. When an error or a set of errors is introduced into this system, the consequent system interventions are structured by the constraints of the preexisting system which they do not destroy. Rather than offering randomness as an account of such phenomena, the analysis encourages a search for regularities in the apparently unstructured events surrounding large‐scale accidents or system failures.
Not in My Town: Conflicting Views on the Siting of a Hazardous Waste Incinerator
Authors: Faragó Klára , Vári Anna , Vecsenyi János
Published: May 2006

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.
Effects of the Chernobyl Accident on Public Perceptions of Nuclear Plant Accident Risks
Authors: Lindell Michael K. , Perry Ronald W.
Published: May 2006

Assessments of public perceptions of the characteristics of a nuclear power plant accident and affective responses to its likelihood were conducted 5 months before and 1 month after the Chernobyl accident. Analyses of data from 69 residents of southwestern Washington showed significant test‐retest correlations for only 10 of 18 variables—accident likelihood, three measures of impact characteristics, three measures of affective reactions, and hazard knowledge by governmental sources. Of these variables, only two had significant changes in mean ratings; frequency of thought and frequency of discussion about a nearby nuclear power plant both increased. While there were significant changes only for two personal consequences (expectations of cancer and genetic effects), both of these decreased. The results of this study indicate that more attention should be given to assessing the stability of risk perceptions over time. Moreover, the data demonstrate that experience with a major accident can actually decrease rather than increase perceptions of threat.
The Effect of Risk Beliefs on Property Values: A Case Study of a Hazardous Waste Site1
Authors: McClelland Gary H. , Schulze William D. , Hurd Brian
Published: May 2006

Health risk beliefs of homeowners near a landfill site were assessed in a survey and compared to expert judgments of the health risks of living near the site. A bimodal distribution of health risk beliefs suggested sharp disagreement between the experts and at least some of the residents. Correlates of high risk beliefs included perception of odor from the site, exposure to media coverage of the problem, having children living at home, age (younger respondents more concerned), and gender (females more concerned). An aggregated neighborhood health risk belief predicted reductions in home prices even after controlling for home physical characteristics, such as size and other disamenities such as proximity to a freeway. In the 4100 homes near the site, the estimated depression in property values was estimated to total about $40.2 million before the site was closed and to be about $19.7 million after closure. Implications of these results for community conflict and for benefit‐cost analysis of hazard site remediation are discussed.
Risk Communication, Knowledge, and Attitudes: Explaining Reactions to a Technology Perceived as Risky
Authors: Bord Richard J. , O'Connor Robert E.
Published: May 2006

Several factors influence peoples’decisions about food irradiation, a technology perceived as risky. Responses to questions about three dimensions of acceptability of food irradiation provide the dependent variables. Risk message characteristics, respondent background characteristics, knowledge, and attitudes form the independent variables. Multiple regression is used to assess relative effects. Levels of acceptability of food irradiation varied somewhat as the focus of the question changed: negative reactions were more likely if the question mentioned serving it to family members than it it stressed self use. The only message manipulation that had a significant impact was information about irradiated food users (e.g., astronauts) and prestigious national and international organizations that endorse food irradiation.

Support for a normative/value type of decision‐making is more substantial than for a rational/technical type of decision‐making. Although knowledge of food irradiation correlates with support for the technology, trust factors are much more powerful predictors. The implications for effective risk communications are discussed.
Risk Assessment for Aflatoxin: II. Implications of Human Epidemiology Data
Authors: Bruce Robert D.
Published: May 2006

A review of epidemiology literature revealed that only studies conducted in Africa and Asia included data adequate to permit quantitative assessment of the dose–response relationship between aflatoxin exposure levels and liver cancer rates. Although these studies were judged adequate, their direct use to predict risks in U.S. populations may be questioned since hepatitis B virus (HBV) infections are far more common in the studied areas than in the U.S. Recent research indicates that, if aflatoxin contributes to the development of liver cancer, it almost always does so in the presence of HBV infection. The African/Asian data do not permit us to estimate the potency of aflatoxin in the absence of HBV. Recognizing this, these data can only be used to establish upper limits for the predicted excess lifetime risk for liver cancer in the U.S. When used in conjunction with aflatoxin exposure estimates for the Southeast U.S., these data predict a liver cancer rate, due to aflatoxin alone, far above that actually observed due to all causes; this provides an indication of the conservatism of this approach. Data from the Southeast U.S. may be used to estimate an excess lifetime risk for liver cancer of 2.17 10‐6 (aflatoxin intake, ng/kg/day).
Chloroform Exposure and the Health Risk Associated with Multiple Uses of Chlorinated Tap Water
Authors: Jo Wan K. , Weisel Clifford P. , Lioy Paul J.
Published: May 2006

Recently, showers have been suspected to be an important source of indoor exposure to volatile organic compounds (VOC). The chloroform dose to an individual from showering was determined based on exhaled breath analysis. The postexposure chloroform breath concentration ranged from 6.0‐21 μg/m3, while all corresponding background breath concentrations were less than 0.86 μg/m3. The internal dose from showering (inhalation plus dermal) was comparable to estimates of the dose from daily water ingestion. The risk associated with a single, 10‐min shower was estimated to be 1.22 10‐4, while the estimated risk from daily ingestion of tap water ranged from 0.130 10‐4 to 1.80 10‐4 for 0.15 and 2.0 L, respectively. Since the estimates of chloroform risk from domestic water use for the three exposure routes—ingestion, inhalation, and dermal—are similar, all routes must be used to calculate the total risk when making policy decisions regarding the quality of the municipal water supply.
Risk Assessment Methodologies for Passive Smoking‐Induced Lung Cancer1
Authors: Repace James L. , Lowrey Alfred H.
Published: May 2006

Risk assessment methodologies have been successfully applied to control societal risk from outdoor air pollutants. They are now being applied to indoor air pollutants such as environmental tobacco smoke (ETS) and radon. Nonsmokers' exposures to ETS have been assessed based on dosimetry of nicotine, its metabolite, continine, and on exposure to the particulate phase of ETS. Lung cancer responses have been based on both the epidemiology of active and of passive smoking. Nine risk assessments of nonsmokers' lung cancer risk from exposure to ETS have been performed. Some have estimated risks for lifelong nonsmokers only; others have included ex‐smokers; still others have estimated total deaths from all causes. To facilitate interstudy comparison, in some cases lung cancers had to be interpolated from a total, or the authors' original estimate had to be adjusted to include ex‐smokers. Further, all estimates were adjusted to 1988. Excluding one study whose estimate differs from the mean of the others by two orders of magnitude, the remaining risk assessments are in remarkable agreement. The mean estimate is approximately 5000 ± 2400 nonsmokers' lung cancer deaths (LCDSs) per year. This is a 25% greater risk to nonsmokers than is indoor radon, and is about 57 times greater than the combined estimated cancer risk from all the hazardous outdoor air pollutants currently regulated by the Environmental Protection Agency: airborne radionuclides, asbestos, arsenic, benzene, coke oven emissions, and vinyl chloride.
Using Related Samples in Assessing Conformance to Safety Goals: A Nuclear Reactor Safety Application
Authors: Brooks Daniel G.
Published: May 2006

Quantifying safety goals is a key to the regulation of activities which are beneficial on the whole but entail some risks in being performed. Determining compliance with safety goals involves dealing with uncertainties. A recent article by Bier(I) describes some of the difficulties encountered using measures with uncertainty to determine compliance with safety goals for nuclear reactors. This paper uses a hierarchical Bayes approach to address two practical modeling problems in determining safety goal compliance under uncertainty: (1) allowing some modeling assumptions to be relaxed, and (2) allowing data from previous related samples to be included in the analysis. The two issues effect each other to the extent that relaxing some assumptions allows the use of a broader range of data. The usefulness of these changes and their impact on assessing safety compliance for nuclear reactors is shown.
Is It Safer to Fly or Drive?
Authors: Evans Leonard , Frick Michael C. , Schwing Richard C.
Published: May 2006

In attempts to soothe the nascent fear of the scheduled airline traveler, passengers waiting takeoff are sometimes reminded of the cliche that they may have already completed the most dangerous part of their trip — the drive to the airport. The objective of this paper is to communicate under what conditions air travel is indeed safer than highway travel and vice versa. The conventional wisdom among risk communicators that air travel is so much safer than car travel arises from the most widely quoted death rates per billion miles for each — 0.6 for air compared to 24 for road. There are three reasons why such an unqualified comparison of aggregated fatality rates is inappropriate. First, the airline rate is passenger fatalities per passenger mile, whereas the road rate is all fatalities (any occupants, pedestrians, etc.) per vehicle mile. Second, road travel that competes with air travel is on the rural interstate system, not on average roads. Third, driver and vehicle characteristics, and driver behavior, lead to car‐driver risks that vary over a wide range. Expressions derived to compare risk for drivers with given characteristics to those on airline trips of given distance showed that 40‐year‐old, belted, alcohol‐free drivers of cars 700 pounds heavier than average are slightly less likely to be killed in 600 miles of rural interstate driving than in airline trips of the same length. Compared to this driver, 18‐year‐old, unbelted, intoxicated, male drivers of cars 700 pounds lighter than average have a risk over 1000 times greater. Furthermore, it is shown that the cliche above is untrue for a group of drivers having the age distribution of airline passengers.
Priority Topics in the Study of Environmental Risk in Developing Countries: Report on a Workshop Held at the East–West Center, August, 1988
Authors: Edgerton Sylvia A. , Smith Kirk R. , Carpenter Richard A. , Siddiqi Toufiq A. , Olive Steven G. , Claudio Corazon Pe Benito , Covello Vincent T. , Fingleton Donald J. , Kim Kwi‐Gon , Wilcox Bruce A.
Published: May 2006

The rapid industrialization occurring in developing regions of the world brings not only economic benefits, but changes in the types and severity of health and environmental problems that each region experiences. As the industrialized world moves toward the use of risk assessment methodologies to aid in problem evaluation and regulatory and policy decision analysis, it seems inevitable that these methodologies will be applied globally. The changes brought about by rapid industrialization, however, must be viewed within the context of societies that are still struggling with the more traditional and basic environmental problems associated with urban and rural poverty. The urgency of development and the lack of adequate resources for characterizing health and environmental changes, often present under these circumstances, offer special challenges to the application of risk assessment methodologies.
An Evaluation of the Rai and Van Ryzin Dose‐Response Model in Teratology
Authors: Carr Gregory J. , Portier Christopher J.
Published: May 2006

The underlying assumptions of the Rai and Van Ryzin dose‐response model for reproductive toxicological data are evaluated on the basis of existing experimental data. The model under consideration is unusual in its use of litter size to completely account for extra‐binomial variation in the data by associating litter size with reproductive outcome. The experimental data show that controlling litter size is not sufficient to account for the litter‐to‐litter variability in responses. It is also shown that the two linear components of the Rai and Van Ryzin model are inappropriate. For the component which applies to the dam, the data suggest a strong nonlinearity, supported by rejection of the linear model via statistical hypothesis tests. In the component involving litter size, a relationship with dose is not apparent. The litter size parameters offer considerable potential for bias in estimation; bias which is at least partly masked by the model having good prediction characteristics due to the increased number of parameters. A simulation study is presented to illustrate how the Rai and Van Ryzin model can exaggerate litter size effects on the probability of response when the simulated data arise from a model involving a nonlinear dam component, common to this type of data, and no effect of litter size.
Fishing a Superfund Site: Dissonance and Risk Perception of Environmental Hazards by Fishermen in Puerto Rico
Authors: Burger Joanna , Gochfeld Michael
Published: May 2006

Risk perception studies show that individuals tend to underestimate significant risks, overestimate negligible ones, and distrust authorities. They also rely on a variety of strategies or heuristics to reach decisions regarding their risk‐taking behavior. We report on a survey of fishermen and crabbers engaged in recreational and subsistence fishing in a Puerto Rican estuary (near Humacao), which has been declared a “Superfund site” because of suspected contamination by mercury, and at ecologically similar control sites. Nearly everyone interviewed at the Humacao site was aware of the mercury contamination, but either denied its importance, believed the contamination was restricted to a distant part of the estuary, or assumed that the estuary would be closed by the authorities if the threat was real. All site‐users consumed the fish and crabs they caught. At Humacao, the average catch was 7 fish per fishermen (mostly tilapia, Tilapia mossambica, and tarpon, Megalops atlantica) and 13 crabs per crabber (all blue crabs, Callinectes sapidus). On average, the site‐users returned to the lagoons about 3‐4 times per month. At control sites, fewer fish were eaten. The worst case consumption of tarpon, a species which concentrated mercury at Eastern Puerto Rico, provided an exposure exceeding the EPA reference dose, whereas consumption of one tarpon per week did not entail excess exposure. Fortunately, few individuals caught tarpon exclusively. Unlike counterparts in the northeastern United States, they trusted authorities and indicated that they would have heeded warnings of mercury contamination posted where they fished.
General Deterrence of Drunk Driving: Evaluation of Recent American Policies
Authors: Evans William N. , Neville Doreen , Graham John D.
Published: May 2006

A testable hypothesis of deterrence theory is that efforts to increase the expected cost of criminal activity by increasing the threat of punishment should, other things being equal, reduce the crime rate. In this paper, we examine whether the incidence of drinking and driving is responsive to escalation of the punitive threat. The recent national campaign against drunk driving provides a natural experiment in which to test the predictions of deterrence theory. Using state level data over the 1975–1986 period, we report no conclusive evidence that any specific form of punitive legislation is having a measurable effect on motor vehicle fatalities. We report suggestive evidence that multiple laws designed to increase the certainty of punishment (e.g., sobriety checkpoints and preliminary breath tests) have a synergistic deterrent effect. The most striking finding is that mandatory seat belt use laws and beer taxes may be more effective at reducing drunk driving fatalities than policies aimed at general deterrence.
Worry Over Technological Activities and Life Concerns
Authors: MacGregor Donald
Published: May 2006

A common mental response to risk is worry. Though generally associated with fear and anxiety, worry is primarily a cognitive activity that can, under some circumstances, be beneficial for developing coping strategies to deal with stressful events. The present study reports an assessment of worry done both before and after the reactor accident at Three Mile Island (TMI). Worries over nuclear risks were assessed in the context of central life concerns such as financial, physical, and interpersonal well‐being. The TMI incident elevated nuclear energy worries to a level near those of central life concerns. The productive value of worry is discussed in terms of its relationship with opportunities for personal control.
Atmospheric Dispersion of Inflammable Substances for Estimating Vulnerable Zones in Hydrocarbon Industry
Authors: Mohan Manju , Singh M. P. , Panwar T. S.
Published: May 2006

The present study utilizes an operational model as well as simple empirical relationships for estimating hazard zones due to fire, explosion, and toxic vapor cloud dispersion. The empirical relationships are based on giving appropriate weightage to each of the parameters on which the hazard in question (viz. fire, explosion, toxic vapour dispersion) is dependent. Results from these two approaches [i.e., an operational model FLAMCALC of U.K. Health and Safety Executive (HSE) and an empirical model named FIREX] have been compared with the data obtained from the Mexico City disaster in 1984. In general, results from the empirical approach and FLAMCALC are comparable to the observed effects.
Estimation of Vulnerable Zones Due to Accidental Release of Toxic Materials Resulting in Dense Gas Clouds
Authors: Singh M. P. , Mohan Manju , Panwar T. S. , Chopra H. V. K.
Published: May 2006

Heavy gas dispersion models have been developed at IIT (hereinafter referred as IIT heavy gas models I and II) with a view to estimate vulnerable zones due to accidental (both instantaneous and continuous, respectively) release of dense toxic material in the atmosphere. The results obtained from IIT heavy gas models have been compared with those obtained from the DEGADIS model [Dense Gas Dispersion Model, developed by Havens and Spicer (1985) for the U.S. Coast Guard] as well as with the observed data collected during the Burro Series, Maplin Sands, and Thorney Island field trials. Both of these models include relevant features of dense gas dispersion, viz., gravity slumping, air entrainment, cloud heating, and transition to the passive phase, etc. The DEGADIS model has been considered for comparing the performance of IIT heavy gas models in this study because it incorporates most of the physical processes of dense gas dispersion in an elaborate manner, and has also been satisfactorily tested against field observations. The predictions from IIT heavy gas models indicate a fairly similar trend to the observed values from Thorney Island, Burro Series, and Maplin experiments with a tendency toward overprediction. There is a good agreement between the prediction of IIT heavy Gas models I and II with those from DEGADIS, except for the simulations of IIT heavy gas model‐I pertaining to very large release quantities under highly stable atmospheric conditions. In summary, the performance of IIT heavy gas models have been found to be reasonably good both with respect to the limited field data available and various simulations (selected on the basis of relevant storages in the industries and prevalent meteorological conditions performed with DEGADIS). However, there is a scope of improvement in the IIT heavy gas models (viz., better formulation for entrainment, modification of coefficients, transition criteria, etc.).

Further, isotons (nomograms) have been prepared by using IIT heavy gas models for chlorine, which provide safe distance for various storage amounts for 24 meteorological scenarios prevalent in the entire year. These nomograms are prepared such that a nonspecialist can use them easily for control and management in case of an emergency requiring the evacuation of people in the affected region. These results can also be useful for siting and limiting the storage quantities.
A Multistage Model of Carcinogenesis Incorporating DNA Damage and Repair
Authors: Portier C. J. , Kopp‐Schneide A.
Published: May 2006

Mathematical models of carcinogenesis are one tool used for research into the mechanisms of carcinogenesis and for assessing risks from exposure to carcinogenic agents. Recent research into carcinogenic mechanisms has focused on the role of cell replication in fixing damage to cellular DNA and increasing the incidence of malignancies. The most commonly used multistage model of carcinogenesis does not explicitly account for DNA damage and the contribution of cell replication rates on the transformation of cells through the various stages. In this manuscript, a generalized multistage model of carcinogenesis is developed in which DNA damage, cell replication, and DNA repair are explicitly included.
Estimating the Value of Avoiding Morbidity and Mortality from Foodborne Illnesses
Authors: Mauskopf Josephine A. , French Michael T.
Published: May 2006

When people consume products violating the Food, Drug, and Cosmetic (FD & C) Act they may experience morbidity or mortality from foodborne illness. Some studies have used survey data to estimate the dollar value of avoiding a few illnesses, but surveys are expensive and the resulting estimates cannot easily be generalized to the wide variety of foodborne illnesses. We develop a method that uses published data to estimate the value of avoiding morbidity and mortality from foodborne illnesses using two metrics–quality‐adjusted life‐years and dollars. The method first describes the effects of different illnesses on the patient and then converts these descriptions into changes in time spent in different health states with different relative utility weights. We use these estimated changes to compute losses in quality‐adjusted life‐years with different illnesses. We then use the empirical literature to estimate a value for these lost quality‐adjusted life‐years. We demonstrate our method and derive estimates for the value of avoiding a future case of botulism, salmonellosis, chronic hepatitis, and bladder cancer. Researchers can use our method to compare the value of avoiding all illnesses caused by violations of the FD & C Act. More importantly, government officials can use our method to quickly and cost‐effectively generate morbidity and mortality valuation estimates for any illness for policy purposes.
Management Errors and System Reliability: A Probabilistic Approach and Application to Offshore Platforms
Authors: Paté‐Cornell M. Elisabeth , Bea Robert G.
Published: May 2006

Probabilistic risk analysis, based on the identification of failure modes, points to technical malfunctions and operator errors that can be direct causes of system failure. Yet component failures and operator errors are often rooted in management decisions and organizational factors. Extending the analysis to identify these factors allows more effective risk management strategies. It also permits a more realistic assessment of the overall failure probability. An implicit assumption that is often made in PRA is that, on the whole, the system has been designed according to specified norms and constructed as designed. Such an analysis tends to overemphasize scenarios in which the system fails because it is subjected to a much higher load than those for which it was designed. In this article, we find that, for the case of jacket‐type offshore platforms, this class of scenarios contributes only about 5% of the failure probability. We link the PRA inputs to decisions and errors during the three phases of design, construction, and operation of platforms, and we assess the contribution of different types of error scenarios to the overall probability of platform failure. We compute the benefits of improving the design review, and we find that, given the costs involved, improving the review process is a more efficient way to increase system safety than reinforcing the structure.
Perception of Risk and Credibility at Toxic Sites
Authors: Mitchell Jerry V.
Published: May 2006

This study integrates previous research methodologies to compare the risk perceptions and responses to risk messages of agency personnel and neighbors of Superfund sites in Michigan. The integration attempted and the focus on risk messages are shaped by a critical review of the social amplification conceptual framework. The study involved all four agency groups and three groups of site neighbors actively involved in Superfund planning across the state. The first part of the study utilized the psychometric techniques of hazard rating and hazard profiles that had not previously been used in studies involving stakeholders. While agency personnel responded similarly to experts in previous studies, the responses of individuals in the neighbor groups reflected experience with toxic sites and were dissimilar to previous ratings by the general public. The second part of the study consisted of a hypothetical toxic site scenario that focused on specific risk messages at different times in the site history. Results indicate that the difference in perception of risk occurs after the first testing at a site, and that dramatic differences arise between agency and resident groups regarding the credibility of information sources and the need for independent testing. A general lack of trust in the Superfund program was demonstrated by all groups. The results indicate that problems of institutional credibility and program adequacy cannot be addressed by better risk comunication.
The Interplay of Science, Values, and Experiences Among Scientists Asked to Evaluate the Hazards of Dioxin, Radon, and Environmental Tobacco Smoke
Authors: Carlo George L. , Lee Nora L. , Sund Kelly G. , Pettygrove Sydney D.
Published: May 2006

To investigate the extent to which personal values and experiences among scientists might affect their assessment of risks from dioxin, radon, and environmental tobacco smoke (ETS), we conducted an experiment through a telephone survey of 1461 epidemiologists, toxicologists, physicians, and general scientists. Each participant was read a vignette designed to reflect the mainstream scientific thinking on one of the three substances. For half of the participants (group A) the substance was named. For the other half (group B), the substance was not named but was identified only as Substance X, Y, or Z. Knowing the name of the substance had little effect on the scientists’ evaluation of dioxin, although those who knew the substance to be dioxin were more likely to rate the substance as a serious environmental health hazard (51% vs. 42%, p= 0.062). For radon, those who knew the substance by name were significantly more likely to consider it an environmental health hazard than were those who knew it as substance Z (91% vs. 78%, p<0.001). Participants who knew they were being asked about ETS rather than substance X were significantly more likely to consider the substance an environmental health hazard (88% vs. 66%, p<0.001), to consider the substance a serious environmental health hazard (70% vs. 33%, p<0.001), to believe that background exposure required public health intervention (85% vs. 41%,p<0.001), and to believe that above‐background exposure required public health intervention (90% vs. 74%, p<0.001). These findings suggest that values and experiences may be influencing health risk assessments for these substances, and indicate the need for more study of this phenomenon.
Expert Judgment in Risk Analysis and Management: Process, Context, and Pitfalls
Authors: Otway Harry , von Winterfeldt Detlof
Published: May 2006

The regulation and management of hazardous industrial activities increasingly rely on formal expert judgment processes to provide wisdom in areas of science and technology where traditional “good science” is, in practice, unable to supply unambiguous “facts.” Expert judgment has always played a significant, if often unrecognized, role in analysis; however, recent trends are to make it formal, explicit, and documented so it can be identified and reviewed by others. We propose four categories of expert judgment and present three case studies which illustrate some of the pitfalls commonly encountered in its use. We conclude that there will be an expanding policy role for formal expert judgment and that the openness, transparency, and documentation that it requires have implications for enhanced public involvement in scientific and technical affairs.
A Malformation Incidence Dose‐Response Model Incorporating Fetal Weight and/or Litter Size as Covariates
Authors: Chen James
Published: May 2006

A dose‐response model is often fit to bioassay data to provide a mathematical relationship between the incidence of a developmental malformation and dose of a toxicant. To utilize the interrelations among the fetal weight, incidence of malformation and number of the live fetuses, a conditional Gaussian regression chain model is proposed to model the dose‐response function for developmental malformation incidence using the litter size and/or the fetal weight as covariates. The litter size is modeled as a function of dose, the fetal weight is modeled as a function of dose conditional on the litter size, and the malformation incidence is modeled as a function of dose conditional on both the litter size and the fetal weight, which itself is also conditional on the litter size. Data from a developmental experiment conducted at the National Center for Toxicological Research to investigate the growth stunting and increased incidence of cleft palate induced by Dexamethasone (DEX) exposure in rats was used as an illustration.
Pharmacokinetic Modeling of Trichloroethylene and Trichloroacetic Acid in Humans
Authors: Allen Bruce C. , Fisher Jeffrey W.
Published: May 2006

The development and application of appropriate physiologically based pharmacokinetic (PBPK) models of chemical contaminants will provide a rational basis for risk assessment extrapolation. Trichloroethylene (TCE) is a widespread contaminant found in soil, groundwater, and the atmosphere. Exposures to TCE and its metabolites have been found to be carcinogenic in rodents. In this study, a PBPK model for TCE and its major metabolite, trichloroacetic acid (TCA), is developed for humans. The model parameters, estimated from the relevant published literature on human exposures to TCE and its metabolites, are described. Key parameters describing the metabolism of TCE and the kinetics of TCA were estimated by optimization. The optimization was accomplished by simultaneously matching model predictions to observations of TCE concentrations in blood and exhaled breath, TCA plasma concentrations, and urinary TCA excretion from five published studies. The optimized human PBPK model provides an excellent description of TCE and TCA kinetics. The predictions were especially good for TCA plasma concentrations following repeated TCE inhalation, an exposure scenario similar to that occurring in the workplace. The human PBPK model can be used to estimate dose metrics resulting from TCE exposures and is therefore useful when considering the estimation of human health risks associated with such exposures.
The Value of Animal Test Information in Environmental Control Decisions
Authors: Taylor Alison C. , Evans John S. , McKone Thomas E.
Published: May 2006

Value of information (VOI)analytic techniques are used to evaluate the benefit of performing animal bioassays to provide information about the cancer potency of specific chemical compounds. These tools allow the identification of the conditions in which the cost of reducing uncertainty about potency, by performing a subchronic or chronic bioassay, is justified by the benefit of having improved information for making control decisions. The decision analytic results are readily scaled to apply to a range of human contact rates (exposures)and a variety of control strategies. The sensitivity of results to uncertainty about animal to human extrapolation and the design of the bioassay is explored. An evaluation of the possible gains in general understanding about the mechanisms of carcinogenicity resulting from chronic bioassays is beyond the scope of this approach.