bluuebunny/crossref_metadata_2025 huggingface dataset:
Executive Functioning in Preschool‐Age Children Prenatally Exposed to Alcohol, Cocaine, and Marijuana
Authors: Noland Julia S. , Singer Lynn T. , Arendt Robert E. , Minnes Sonia , Short Elizabeth J. , Bearer Cynthia F.
Published: May 2006

Background: Reports from clinical and experimental (animal) research converge on the suggestion that prenatal exposure to alcohol, cocaine, or marijuana undermines executive functioning (EF) and its neurological underpinnings. However, large, adequately controlled, prospective studies of alcohol and marijuana effects on EF have reported conflicting findings, and there have been no such studies of cocaine exposure.

Methods: EF was investigated in a cohort (n= 316) of 4‐year‐old children the majority of whose mothers had used varying combinations of cocaine, alcohol, and marijuana during pregnancy. With use of postpartum maternal report and biological assay, children were assigned to overlapping prenatal cocaine‐exposed, alcohol‐exposed, and marijuana‐exposed groups and to complementary control groups. The postnatal environmental assessment included measures of maternal intellectual and psychosocial functioning, current drug or alcohol use, and home environment.

Results: The children in the alcohol‐exposed group had worse tapping‐inhibition performance than children in the non‐alcohol‐exposed group, and this effect persisted when potential confounding environmental variables, other drug variables, and concurrent verbal intelligence were controlled for.

Conclusions: Prenatal alcohol is predictive of decreased EF in early childhood that could not be attributed to environmental factors. The results are discussed in terms of the age and overall high‐risk status of the children.
Effects of Alcohol, Personality, and Provocation on the Expression of Anger in Men: A Facial Coding Analysis
Authors: Parrott Dominic J. , Zeichner Amos , Stephens Dana
Published: May 2006

Background: Research has demonstrated that alcohol‐related aggression is modulated by anger‐based personality traits. However, it is unclear how anger, as a concomitant of aggression, is affected by an interaction among these variables. The present study evaluated the effects of alcohol, anger‐based traits, and physical provocation on anger.

Methods: Participants were 136 male social drinkers who completed measures designed to assess trait anger and anger expression styles and were assigned to an alcohol or no‐alcohol control beverage group. Participants engaged in a competitive reaction time task in which electric shocks were received from a fictitious opponent. Participants’ experience of anger was assessed unobtrusively via the Facial Action Coding System.

Results: Intoxicated participants displayed more facial expressions of anger than sober participants. Interactive effects between anger expression styles and beverage group also were detected in that, among intoxicated participants, a positive relationship between facial expressions of anger and the tendency to express anger outwardly was found after high, but not low, provocation. This relationship was not observed at either provocation level in the no‐alcohol control group. Similarly, whereas participants’ tendency to control anger resulted in fewer facial expressions of anger by intoxicated participants, no such relationship was found among sober participants.

Conclusions: Findings suggest that alcohol intoxication facilitates the experience of anger after provocation and enhances the relationship between state anger and behavioral tendencies to control anger expression.
Value of a Life: What Difference Does It Make?1
Authors: Graham John D. , Vaupel James W.
Published: May 2006

A comparison of the costs and benefits of 57 lifesaving programs reveals striking disparities across agencies and programs in cost/life saved and even greater disparities in cost/life‐year saved. Within a broad range the monetary value assigned to the benefits of averting a death usually does not alter the policy implications of the analyses. The findings suggest that despite the substantial disagreements and uncertainties in the theory and practice of valuing lives, careful quantitative analysis can be helpful in setting health, safety, and environmental priorities.
Risk Management and Decision Rules for Light Water Reactors
Authors: Griesmeyer J. Michael , Okrent David
Published: May 2006

A quantitative approach to risk management for accidents in light water nuclear power reactors is proposed to serve as one focus for discussion. In this proposal risk management is divided into two major tasks: the predominantly social and political task of setting the safety goals and the technical task of estimating the risks and deciding whether the safety goals have been met. The proposed safety goals include limits on the following: risk to the individual of early death or delayed cancer death; overall societal risk of early or delayed death; and the frequency of core melt accidents as well as the frequency of containment failure, given a core melt. Also included are a small element of risk aversion and an “as low as reasonably achievable” (ALARA) approach with a cost‐effectviness criterion which includes both economic and health effects.
Methods for Uncertainty Analysis: A Comparative Survey
Authors: Cox David C. , Baybutt Paul
Published: May 2006

This paper presents a survey and comparative evaluation of methods which have been developed for the determination of uncertainties in accident consequences and probabilities, for use in probabilistic risk assessment. The methods considered are: analytic techniques, Monte Carlo simulation, response surface approaches, differential sensitivity techniques, and evaluation of classical statistical confidence bounds. It is concluded that only the response surface and differential sensitivity approaches are sufficiently general and flexible for use as overall methods of uncertainty analysis in probabilistic risk assessment. The other methods considered, however, are very useful in particular problems.
A Risk Evaluation of the Chlorine Industry in North America
Authors: Helmeste Richard J. , Phillips Colin R.
Published: May 2006

This study analyzes the risk involved in the chlorine industry in North America. A hypothetical chlorine plant with diaphragm electrolytic cells and a chlorine production of 300,000 metric tons per year was studied. Risk in terms of man‐days lost per year was evaluated for nine stages in the manufacture and distribution of chlorine. The highest risk was found to be “Maintenance of the Chlorine Plant” (37.6% of total man‐days lost per year). “Raw Material Acquisition for Materials in Chlorine Plant” (1.3%) and “Storage of Chlorine at Chlorine Plant” (0.3%) both had very little risk. “Transport of Chlorine to User by Rail, Pipeline, Barge, and Truck Combined” also gave relatively low risk (10.2%), an important result since this risk is involuntary and is the category that usually causes the most concern. The kind of risk evaluation presented here, while relatively new, should be helpful in identifying those areas in industry on which time and money can be spent with maximum benefit to reduce risk.
Long‐Term Consequences of the Linear‐No‐Threshold Dose‐Response Relationship for Chemical Carcinogens
Authors: Cohen Bernard L.
Published: May 2006

U.S. Government agencies have adopted a linear‐no‐threshold dose‐response relationship for chemical carcinogens, and have set up a Carcinogen Assessment Group (CAG) to determine the proportionality constants in these relationships. Their results are summarized for the carcinogenic elements Be, Cr, Ni, As, and Cd. It is shown that when effects are integrated over ∼105 years, an atom of these elements in the ground has a reasonable chance (10‐4‐10‐1)of being ingested orally by a human. From this it is shown that, over this time period, producing electricity by coal burning causes 320 fatalities/GWe‐yr and all coal burning in the United States causes 74,000 fatalities/year. Commercial use of these carcinogenic elements causes the following numbers of fatalities/yr: Be–900, Cr–87,000, Ni–10,000, As–62,000, and Cd–230,000. Use of CdS and GaAs photovoltaics would cause 2200 and 66 fatalities/GWe‐yr, respectively, and production of construction materials for photovoltaic arrays would cause 11 fatalities/GWe‐yr through use of coal. The calculational methods are derived from those used in risk assessments of radioactive wastes, and their questionable aspects apply equally to those assessments. It is shown that, contrary to present beliefs, it is much safer to dump these elements into rivers than to bury them in the ground, and by far the safest procedure is to dump them in the oceans.
Artifactual Uncertainty in Risk Analysis
Authors: Cox Louis Anthony
Published: May 2006

The field of comparative risk analysis of electrical energy alternatives has traditionally been plagued by highly uncertain estimates of risk rates, and consequently by conflicting judgements of relative risk. To the extent that this uncertainty arises from traditional sources–imperfect observations or actual variance in the data–it can be brought within a Bayesian statistical framework which allows policy conclusions to be formulted and tested at different levels of confidence. It is shown that there are important methodological or “artifactual” sources of uncertainty, however, that cannot be treated by statistical means; these require conceptual advances for their resolution. By identifying these sources of uncertainty in simple thought experiments and examples, it is shown in what ways the concept of attributable risk, which is the policy‐maker's chief concern, must be sharpened and refined to have unambiguous meaning. The conventional “multilinear” formula for calculating risk indices is challenged as a measure of attributable risk, and directions for further research to improve the methodological foundations of comparative risk analysis are identified.
An Illustration of Matrix Formulation for a Probabilistic Risk‐Assessment Study
Authors: Sancaktar Selim
Published: May 2006

A matrix formulation is described and numerically illustrated to calculate the public risk and identify the dominant contributors to it arising from the operation of a nuclear power plant. The matrix methodology is used as a superstructure in a probabilistic risk‐assessment study to organize the calculated probabilities and to facilitate the analysis and documentation effort. The matrix structure is built to manipulate the large amount of data arising from event and fault‐tree analysis and other supporting analyses. It lends itself easily to computerization and provides an analytic capability to identify dominant contributors to risk. It is a useful tool for aiding sensitivity analyses and also a potential formalism for standardization of risk‐assessment studies. This tool is already used in the two recent comprehensive nuclear power plant risk‐assessment efforts, the Zion and Indian Point Safety Studies.
Evacuation Risks: A Tentative Approach for Quantification
Authors: Bastien M. C. , Dumas M. , Laporte J. , Parmentier N.
Published: May 2006

This study tries to assess the risk of deaths and injuries from motor vehicle accidents associated with an evacuation of population groups in case of nuclear plant accidents. The risk per person–km is evaluated using: (a) data from previous evacuation: information from Soufriere evacuation (Guadeloupe Island 1976) and Mississauga (1979), added to Hans and Sell's data: no road accident occurred for a sample of 1,500,000 persons; (b) national recording system for motor vehicle accident: the rates of 2.2 10 ‐8 deaths per person–km and 32 10‐8 injuries per person–km is calculated as an average. These last rates in France overestimate the number of casualties. A reasonable hypothesis is to assume that the probability of road accident occurrence follows a Poisson distribution, as these events are independent and unfrequent, as no accident was observed in a sample of 1,500,000 persons the probability is between 0 and an upper value of 0.24 10‐8 deaths per person‐km and 3.29 10‐8 injuries per person–km. The average and maximum population involved within different radii around French and U.S. Nuclear power sites are taken as a sample size in order to study the total risk of deaths and injuries in the hypothesis of an evacuation being necessary to protect the populations.
Powerline Frequency Electric and Magnetic Fields: A Pilot Study of Risk Perception
Authors: Morgan M. Granger , Slovic Paul , Nair Indira , Geisler Dan , MacGregor Donald , Fischhoff Baruch , Lincoln David , Florig Keith
Published: May 2006

The perception of the potential risk arising from human exposure to 50/60 Hz electric and magnetic fields was studied with a quasi‐random sample of 116 well‐educated, opinion leaders using the risk perception framework previously developed by Slovic, Fischhoff, and Lichtenstein. These individuals rated exposure to fields from transmission lines and electric blankets on a variety of scales that have been found useful in characterizing people's risk attitudes and perceptions. These judgments allowed us to conjecture about the likely desire for regulation of these potential hazards and the likely response to a publicized problem (e.g., an accident or ominous research finding) involving these two sources of exposure. Various forms of detailed information about 50/60 Hz fields were supplied to respondents. The provision of information produced modest, but statistically significant, changes in perceptions in the direction of greater concern about the risks. In response to questions of public policy, participants desired modest regulatory control of field exposure from transmission lines and little or no control of field exposure from appliances like electric blankets.
Ambiguous Carcinogens and Their Regulation1
Authors: Weinberg Alvin M. , Storer John B.
Published: May 2006

Examination of five animal and one human studies suggest that certain agents increase the incidence of some cancers but simultaneously reduce the incidence of other cancers. Yellow die 3, for example, sharply increases the incidence of liver tumors but practically eliminates naturally occurring leukemia/lymphoma in F‐344 male rates. Such ambiguity in the action of presumed carcinogens suggests that caution must be used by regulatory bodies in proscribing suspected carcinogens, or even in recommending changes in lifestyle or dietary habits as a means of reducing incidence of cancer.
Medical Decision Making and Elective Surgery: The Case of Hysterectomy
Authors: Travis Cheryl Brown
Published: May 2006

Review and analyses of three sources of data are presented indicating that 25% of hysterectomies are elective. Annual mortality associated with elective hysterectomy is estimated to be 319, or about 12,122 woman years. Cost‐benefit analyses of mortality, life expectancy, morbidity, psychological sequelae, as well as dollar expenditures, reveal high costs and relatively limited benefits. Explanations for this apparent anomaly in decision making are explored and include economic incentives, system structure, sexism, and cancer prophylaxis. Principles of risk perception are discussed in terms of potential biases associated with the cancer prophylaxis motive. It is suggested that physicians’judgements of risk may be more salient to the decision process than those of prospective patients.
Statistical Modeling of Animal Bioassay Data with Variable Dosing Regimens: Example—Vinyl Chloride
Authors: Brown Kenneth G. , Hoel David G.
Published: May 2006

We consider animal bioassay experiments with variable dosing regimens in which groups of animals are dosed beginning at different ages and for varying durations. Two response models are discussed and then applied to data from an experiment on vinyl chloride exposure of F‐344 rats, B6C3F1 and Swiss CD‐1 mice, and Syrian Golden hamsters. The multistage model of Armitage and Doll,(1) as extended by Whittemore,(2) Day and Brown,(3) and Crump and Howe,(4) is used to estimate the dose effect on the ordered stages of tumor development. The data for all endpoints and species/strains examined consistently indicate a predominant effect on the first stage, suggesting that vinyl chloride is primarily a tumor initiator. This is consistent with evidence from two‐stage experiments on this chemical.5The second response model, new to this article, adjusts for survival nonparametrically. It is used to test for an age difference in susceptibility, to evaluate alternative exposure durations, and to compare the effectiveness of alternative dosing regimens for detecting carcinogenicity.
Multistage Model Interpretation of Additive and Multiplicative Carcinogenic Effects1
Authors: Gibb Herman J. , Chen Chao W.
Published: May 2006

Under the assumption of multistage carcinogenesis, a multiplicative carcinogenic effect would be produced by the action of different carcinogens in a mixture on different stages of the carcinogenic process. An additive effect would be produced by the effect of different carcinogens on the same stage. A mathematical argument for these hypotheses is presented here.
Intersystem Common Cause Analysis of a Diesel Generator Failure
Authors: Plastiras Joan K.
Published: May 2006

The methodology and results reported in this paper are based on an analysis of a hypothetical accident occurring in a two unit power plant with shared systems (i.e., the diesel generator, the emergency service water, and the residual heat removal service water systems). The accident postulated is a loss of coolant accident (LOCA) in one out of two nuclear units in conjunction with a loss of offsite power (LOOP) and a failure of one out of four diesel generators to start. To analyze the intersystem effects, we needed to develop and apply a new methodology, intersystem common cause analysis (ICCA). The ICCA methodology revealed problems which were not identified by the traditional intrasystem failure modes and effects analysis (FMEA) performed earlier by the design teams. The first potential problem arises if one unit experiences a LOCA and diesel generator failure while one loop of its residual heat removal system is in the suppression pool cooling mode (SPCM); in this event, it is likely that minimum emergency core cooling system (ECCS) requirements will not be met. The second potential problem arises if a diesel generator fails while both units are simultaneously subjected to a controlled forced shutdown (a LOCA need not be postulated for either unit); in this event, it is likely that one unit will be required to use a heat removal path identified as off‐normal in the final safety analysis report (FSAR) for the two unit plant. These and other potential concerns identified through application of the ICCA presented here were resolved early in the design phase.
An Analysis of Damage to U.S. Soybean Yields from 1982 Acid Deposition Levels
Authors: Moskowitz Paul D. , Medeiros William H. , Oden Neal L. , Thode Henry C. , Coveney Elizabeth A. , Rosenthal Robert E.
Published: May 2006

Experimental data were compiled for seven soybean varieties studied at four different locations in the U.S. for a period of one to three years. Three dose–response functions (linear, quadratic, and Weibull) were fitted, as appropriate, to the experimental data. Effects of acid deposition on soybean yields were estimated by combining variety‐specific dose–response and production data. These calculations suggest that U.S. soybean production (2.2 billion bushels in 1982) would increase by 3.2 million bushels with a 10% reduction in 1982 hydrogen ion concentration levels in all counties where soybeans were grown, and by almost 70 million bushels with uniform improvement to pH 5.2. These estimates are based on many simplifying assumptions and are subject to several important sources of uncertainty explored in this study. The calculated changes are small in comparison with effects from other natural and anthropogenic stresses.
On the Use of the Cause Table in Handling Common Cause Events in System Analysis
Authors: Kaplan Stan , Fleming Karl N.
Published: May 2006

A method is presented for applying the cause table concept to the problem of common cause events. This method can be regarded as an alternative to the approach in which these events are included directly into the system fault trees. In comparison with this approach, the cause table method offers the advantage of simple fault trees, convenient visibility of the contributions of causes, and the ability to truncate the numerical calculation conveniently by aggregating small terms into an “other” category. Generally speaking, the cause table method can be said to handle common causes at the level of arithmetic (i.e., numbers) rather than at the level of algebra (determining cutsets and frequency equations).
Risk Communication in the Real World
Authors: Konheim Carolyn S.
Published: May 2006

Rigorous health risk assessments of site‐specific projects are generally little understood by nontechnical decision makers and the public and often appear to them to obfuscate a straightforward answer to their fundamental question: “Is the project safe?” The focus on risk, usually out of context of benefits, deprives the reader of the opportunity to make a fully informed decision on the proposal. While the risk assessment tools may need to be refashioned, confidence in the analytical process can be improved, partly through more citizen involvement, as well as through more effective communication of the conservatism of the assumptions, the thoroughness of the process, and the significance of the results in comparison to other commonly accepted involuntary exposures and risks.
Chernobyl's Effects on the Perceived Risks of Nuclear Power: A Small Sample Test
Authors: McDaniels Timothy L.
Published: May 2006

This paper presents the results of two risk perception surveys, one taken just before and one just after the accident at Chernobyl in May, 1985. The results show that Chernobyl affected short‐term perceptions of nuclear power risks in ways that are predictable and measureable. In this sample, perceived levels of dread of nuclear power increased, perceived knowledge increased, and perceived severity decreased. Overall, the results are informative about how a single event could affect perceived risk characteristics.
An Investigation of Uncertainty and Sensitivity Analysis Techniques for Computer Models
Authors: Iman Ronald L. , Helton Jon C.
Published: May 2006

Many different techniques have been proposed for performing uncertainty and sensitivity analyses on computer models for complex processes. The objective of the present study is to investigate the applicability of three widely used techniques to three computer models having large uncertainties and varying degrees of complexity in order to highlight some of the problem areas that must be addressed in actual applications. The following approaches to uncertainty and sensitivity analysis are considered: (1) response surface methodology based on input determined from a fractional factorial design; (2) Latin hypercube sampling with and without regression analysis; and (3) differential analysis. These techniques are investigated with respect to (1) ease of implementation, (2) flexibility, (3) estimation of the cumulative distribution function of the output, and (4) adaptability to different methods of sensitivity analysis. With respect to these criteria, the technique using Latin hypercube sampling and regression analysis had the best overall performance. The models used in the investigation are well documented, thus making it possible for researchers to make comparisons of other techniques with the results in this study.
Mental Models in Risk Assessment: Informing People About Drugs
Authors: Jungermann Helmut , Schütz Holger , Thüring Manfred
Published: May 2006

One way to communicate about the risks of drugs is through the use of package inserts. The problems associated with this medium of informing patients have been investigated by several researchers who found that people require information about drugs they are using, including extensive risk information, and that they are willing to take this information into account in their usage of drugs. But empirical results also show that people easily misinterpret the information given. A conceptual framework is proposed that might be used for better understanding the cognitive processes involved in such a type of risk assessment and communication. It is based on the idea that people develop, through experience, a mental model of how a drug works, which effects it might produce, that contraindications have to be considered, etc. This mental model is “run” when a specific package insert has been read and a specific question arises such as, for example, whether certain symptoms can be explained as normal or whether they require special attention and action. We argue that the mental model approach offers a useful perspective for examining how people understand package inserts, and consequently for improving their content and design. The approach promises to be equally useful for other aspects of risk analysis that are dependent upon human judgment and decision making, e.g., threat diagnosis and human reliability analysis.
Using the Biological Two‐Stage Model to Assess Risk from Short‐Term Exposures
Authors: Chen James J. , Kodell Ralph L. , Gaylor David W.
Published: May 2006

Two assumptions used in risk assessment are investigated: (1) the assumption of fraction of lifetime dose rate assumes that the risk from a fractional lifetime exposure at a given dose rate is equal to the risk from full lifetime exposure at that same fraction of the given dose rate; (2) the assumption of fraction of lifetime risk assumes that the risk from a fractional lifetime exposure at a given dose rate is equal to that same fraction of the risk from full lifetime exposure at the same dose rate. These two assumptions are equivalent when risk is a linear function of dose. Thus both can be thought of as generalizations of the assumption that cancer risk is proportional to the total accumulated lifetime dose (or average daily dose), which is often made to assess the risk from short‐term exposures. In this paper, the age‐specific cumulative hazard functions are derived using the two‐stage model developed by Moolgavkar, Venzon, and Knudson for situations when the exposure occurs during a single period or at a single instant. The two assumptions described above are examined for three types of carcinogens, initiator, completer, and promoter, in the context of the model. For initiator and completer, these two assumptions are equivalent in the low‐dose region; for a promoter, using the fraction of lifetime risk assumption is generally more conservative than that of the fraction of lifetime dose rate assumption. Tables are constructed to show that the use of either the fraction of lifetime dose rate assumption or the fraction lifetime risk assumption can both underestimate and overestimate the true risk for the three types of carcinogens.
Does a Reactor Need a Safety Backfit? Case Study on Communicating Decision and Risk Analysis Information to Managers
Authors: Brown Rex V. , Ulvila Jacob W.
Published: May 2006

An approach to communicating decision and risk analysis findings to managers is illustrated in a real case context. This article consists essentially of a report prepared for senior managers of the Nuclear Regulatory Commission to help them make a reactor safety decision. It illustrates the communication of decision analysis findings relating to technical risks, costs, and benefits in support of a major risk management decision: whether or not to require a safety backfit. Its focus is on the needs of decision makers, and it introduces some novel communication devices.
Ex Ante and Ex Post Values for Changes in Risks
Authors: Freeman A. Myrick
Published: May 2006

In this paper, I take risk to mean a composite of the probability of an adverse event and the severity of the consequences of the event. I explore two issues in the economic valuation of changes in individual risks brought about by public policies. These are: (1) the relationship between the values of risk prevention (i.e., the lowering of the probabilities of adverse events) and risk reduction (i.e., the reduction of the severity of the consequences of adverse events); and (2) the relationship between ex ante and ex post measures of the value of changes in risk.
Assessing Crew Response Probability for a Sequence of Actions with an Overall Time Constraint
Authors: Vestrucci Paolo
Published: May 2006

The following situation has been considered: during an accident sequence, a crew has to do a proper set of actions within a finite time window in order to achieve a specific goal. The operator actions are considered independent, they are lined up in series, and a single failure leads to mission failure. This paper proposes a general methodology for assessing the crew response (or success) probability, through a convolution integral formulation. This method is general and can be applied to any response probability model; an application to the Human Cognitive Reliability model is given.
Public Perceptions of the Risks and Benefits of Technology1
Authors: Gardner Gerald T. , Gould Leroy C.
Published: May 2006

This study attempted to verify and extend previous research on people's perceptions of the risks and benefits of technology and their judgments concerning the acceptability of technology safety regulations. The study addressed several limitations of prior work, in that: (1) it was the first “expressed‐preference” study to collect data from large, representative samples of Americans; (2) the research design made “person,” rather than “technology,” the unit of statistical analysis; and (3) the study employed an expanded set of independent variables, including three qualitative benefit characteristics. The results confirmed several major conclusions of prior expressed‐preference research, the most important being that members of the public tend to define “risks,”“benefits,” and “acceptability” in a complex, multidimensional manner; and that their definitions differ significantly from those used by professional risk‐managers and other technical experts in quantitative assessments of risk and acceptability. The results also indicated that people's stances toward technology regulation tend to cut across traditional sociodemographic lines.
Informing the Public About Uncertain Risks
Authors: Weterings Rob A.P.M. , Van Eijndhoven Josée C.M.
Published: May 2006

Many problems arise in connection with the communication of risk information. In this article the content of the information communicated is taken as a starting‐point for analyzing the risk communication process. We studied the way in which authorities communicated health risks to local residents in Dutch soil pollution situations and found that communication problems were characterized more by misunderstanding and conflict between parties with different views and interests than by a lack of understanding. Therefore, it is important to look more closely at the way the communicators of information (in our cases, officials) select risk information from risk assessments, and to study the effects that the information selected has on the receivers (in our cases, residents). Both the process of selection by the officials and the process of interpretation by the residents will be shown to be influenced by the different institutional backgrounds. The article presents a new approach to risk communication. Both the risk information presented by the authorities and the public reactions to this risk information are considered to reflect the institutional background of authorities and residents, and can be analyzed in these terms. Such an approach has consequences for the study of risk communication and the manner in which it is practiced.
A Dose‐Response Analysis of Skin Cancer from Inorganic Arsenic in Drinking Water1
Authors: Brown Kenneth G. , Boyle Kerrie E. , Chen Chao W. , Gibb Herman J.
Published: May 2006

A study of the prevalence of skin cancer among 40,421 persons consuming arsenic‐contaminated drinking water in Taiwan was used for a cancer dose‐response assessment of ingested arsenic. The numbers of persons at risk over three dose intervals and four exposure durations were estimated from the data in order to apply the method of maximum likelihood to a multistage‐Weibull time/ dose–response model. A constant exposure level since birth for each of the exposure categories was assumed. It was found that the cumulative hazard increases as a power of three in age, and is linear or quadratic (with a linear coefficient) in dose. Observations from a smaller epidemiologic survey in Mexico were similar to what would be predicted from the model of the Taiwan data. Assuming that the skin cancer risk from ingested arsenic in the American population would also be similar to the Taiwan population, an American male would have a lifetime risk of developing skin cancer of 1.3 × 10−3 (3.0 × 10−3) if exposed to 1 μg/kg/day for a 76‐year lifespan (median lifespan in the U.S.).
Simplified Containment Event Tree Methodology Applied to Peach Bottom SBO‐ST Sequences1
Authors: Galyean William J. , Wagner K. C. , Dallman R. Jack
Published: May 2006

The methodology presented here identifies an approach to accurately and economically analyze the effects on risk of various containment performance issues. Although this method facilitates the evaluation of potential containment improvements, it does so while utilizing the significant amount of information accumulated by the U.S. NRC Reactor Risk Reference Program. The use of hindsight and the acceptance of point estimate quantifications of risks allows the proposed methodology to be scrutable and understandable to the community as well as relatively simple and inexpensive to apply. A study of containment venting strategies was used to demonstrate the capabilities of the simplified containment event tree methodology. However, the methodology is flexible enough for a wide range of risk evaluations.
Multistage Modeling of Lung Cancer Mortality Among Arsenic‐Exposed Copper‐Smelter Workers
Authors: Mazumdar Sati , Redmond Carol K. , Enterline Philip E. , Marsh Gary M. , Costantino Joseph P. , Zhou Susan Y. J. , Patwardhan Rita N.
Published: May 2006

Multistage modeling incorporating a time‐dependent exposure pattern is applied to lung cancer mortality data obtained from a cohort of 2802 arsenic‐exposed copper‐smelter workers who worked 1 or more years during the period 1940–1964 at a copper smelter at Tacoma, Washington. The workers were followed for death through 1976. There were 100 deaths due to lung cancer during the follow‐up period. Exposures to air arsenic levels measured in μ/m3 were estimated from departmental air arsenic and workers urinary arsenic measurements. Relationships of different temporal variables with excess death rates are examined to judge qualitatively the implications of the multistage cancer process. Analysis to date indicates a late stage effect of arsenic although an additional early stage effect cannot be ruled out.
Interspecies Conversion of Kinetically Equivalent Doses1
Authors: O'Flaherty Ellen J.
Published: May 2006

A framework is presented within which to organize consideration of appropriate measures of delivered dose and selection of an appropriate procedure for interspecies conversion of kinetically equivalent doses. Systematic species dependencies of simple kinetic relationships between administered and delivered dose are developed. Interspecies scaling of kinetic parameters, including firstorder rate constants and maximum rates of capacity‐limited processes, is discussed, and the effects of conventional scaling procedures on initial and steady‐state concentrations and on areas under the blood concentration curve are shown. Particular attention is given to production of reactive metabolites. It is shown that interspecies dose or dose rate conversion on the basis of the 3/4 power of body weight is consistently either realistic or conservative when the conversion is carried out from smaller to larger species, except when first‐order elimination and capacity‐limited production of an active metabolite coexist. In this case, the 3/4 power of body weight conversion procedure may be either overpredictive or underpredictive, depending on the relative dependence of the efficiency of metabolite production and elimination on species body weight. Interspecies dose conversion on a direct mg/kg body weight basis is consistently much less conservative than the 3/4 power of body weight procedure, resulting when scaling from smaller to larger species in underestimation of delivered dose or of steady‐state concentration of both parent and metabolite for all of the kinetic relationships considered. Applicability and limitations of these procedures are also discussed.
What Do We Know About Making Risk Comparisons?
Authors: Roth Emilie , Morgan M. Granger , Fischhoff Baruch , Lave Lester , Bostrom Ann
Published: May 2006

The risks of unfamiliar technologies are often evaluated by comparing them with the risks of more familiar ones. Such risk comparisons have been criticized for neglecting critical dimensions of risky decisions. In a guide written for the Chemical Manufacturers Association, Covello et al.(1) have summarized these critiques and developed a taxonomy that characterizes possible risk comparisons in terms of their acceptability (or objectionableness). We asked four diverse groups of subjects to judge the acceptability of 14 statements produced by Covello et al. as examples of their categories. We found no correlation between the judgments of acceptability produced by our subjects and those predicted by Covello et al..
Associations Between Morbidity and Alternative Measures of Particulate Matter
Authors: Ostro Bart D.
Published: May 2006

This paper explores the association between acute respiratory morbidity and different measures of exposure to airborne particulate matter, including sulfates, total suspended particulates, and fine and inhalable particulates. Regression analysis was used to test for the impacts of these alternative measures of particulate matter on respiratory morbidity using the 1979–1981 annual Health Interview Surveys and EPA's Inhalable Particle Monitoring Network. The general results indicate that, of the surrogate measures for particulate matter, sulfates appear to have the greatest association with morbidity. To the extent that sulfuric acid aerosols are correlated with airborne sulfates, the results suggest that respiratory impairment sufficient to lead to days of reduced activity may be related to the existence of acidity in the air. These findings are consistent with the results of ecological studies reporting an association between mortality and exposures to fine particles and sulfates.
Public Attitudes Toward Siting a High‐Level Nuclear Waste Repository in Nevada
Authors: Kunreuther Howard , Easterling Douglas , Desvousges William , Slovic Paul
Published: May 2006

This paper examines the sources of public opposition to a high‐level nuclear waste repository among samples of 1001 residents of Nevada and a national sample of 1201 residents. Two models of choice are contrasted: A benefit‐cost model and a risk‐perception model of individual choice. The data suggest that the willingness of Nevada residents to accept a repository at Yucca Mountain depends upon subjective risk factors, especially the perceived seriousness of risk to future generations. Perceived risk depends in part on level of trust placed in the Department of Energy to manage a repository safely. Opposition to a local repository did not decrease significantly if compensation in the form of annual rebates, either ($1000, $3000, or $5000 per year for 20 years) were offered to residents. The public needs to be convinced before compensation is considered, that the repository will possess minimal risks to themselves as well as to future generations, and that the site currently targeted is suitable. One way to do this is through adoption of mitigation and control procedures such as strict federal standards and local control over the operation of the repository. The federal government should also consider returning to the fair procedure for selection between candidate sites specified in the initial Nuclear Waste Policy Act of 1982.
Risk Assessment for Aflatoxin: I. Metabolism of Aflatoxin B1 by Different Species
Authors: Gorelick Nancy J.
Published: May 2006

A comparison of the generation and detoxification of reactive aflatoxin B1 metabolites in different species may elucidate why animal species vary widely in sensitivity to aflatoxin B1 carcinogenicity, in addition to offering some perspective on how sensitive man may be to the carcinogenic effects of this mycotoxin. Scientific literature comparing the ability of cellular fractions from different species to metabolize aflatoxin B1 is reviewed. However, in vitro studies exclude components for multiple metabolic pathways, eliminating the possibility of competition between metabolic activation and detoxification. Quantification of metabolic activation by different species from these studies is therefore limited. The species‐specific carcinogenic potency of aflatoxin B1 may be reflected in levels of aflatoxin B1‐DNA adducts generated in vivo. The current paucity of quantitative information on human DNA adduct levels does not permit comparision between different species on this basis.
Major Sources of Exposure to Benzene and Other Volatile Organic Chemicals1,2
Authors: Wallace Lance
Published: May 2006

The major sources of human exposure to about a dozen volatile organic chemicals (VOCs) have recently been identified.1 For nearly every chemical, the major sources of exposure are completely different from the major sources of emissions. This finding implies that current environmental regulations and control strategies are misdirected. Important sources of exposure are typically not regulated in any way, whereas unimportant sources are heavily regulated. Vast sums of money are spent on problems involving little risk (e.g., hazardous waste sites), whereas few resources are expended on problems involving higher risk (e.g., indoor air pollution). The following paper summarizes recent findings regarding major sources of exposure to several VOCs. Benzene is selected as a case study. Brief discussions of tetrachloroethylene and paradichlorobenzene are also included.
Desired Risk: Broadening the Social Amplification of Risk Framework1
Authors: Machlis Gary E. , Rosa Eugene A.
Published: May 2006

Recently Kaspersonet al.(6)have proposed a conceptual framework, “The Social Amplification of Risk,” as a beginning step in developing a comprehensive theory of public experience of risk. A central goal of their effort is to systematically link technical assessments of risk with the growing findings from social scientific research. A key and growing domain of public risk experience is “desired” risk, but this is virtually neglected in the framework. This paper evaluates the scope of the “Social Amplification of Risk Framework,” asking whether it is applicable to desired risks, such as risk recreation (hang gliding, mountain climbing, and so forth). The analysis is supportive of the framework's applicability to the domain of desired risk.
Two‐Event Model for Carcinogenesis: Biological, Mathematical, and Statistical Considerations
Authors: Moolgavkar Suresh H. , Luebeck Georg
Published: May 2006

A two‐mutation model for carcinogenesis is reviewed. General principles in fitting the model to epidemiologic and experimental data are discussed, and some examples are given. A general solution to the model with time‐dependent parameters is developed, and its use is illustrated by application to data from an experiment in which rats exposed to radon developed lung tumors.
Cancer Fatalities from Waterborne Radon (Rn‐222)
Authors: Crawford‐Brown Douglas J.
Published: May 2006

A model of the biokinetics of radon in the human body following ingestion is developed from existing data. Calculations of the probability of cancer fatality from use of radon‐laden water in the home then are presented. The pathways of emanation and ingestion are examined and shown to lead to roughly equal risks. The probability of fatal cancer resulting from lifetime use of water at a radon concentration of 1 pCi/L is shown to be 1 × 10−6, with a reasonable range between 2 × 10−7 and 5 × 10−6. The allowed concentration consistent with an excess risk of 10−4 then is approximately 100 pCi/L, which is exceeded in a significant fraction of U.S. water supplies. The lifetime number of premature deaths due to waterborne radon in the U.S. is estimated to lie between 5000 and 125,000, with a best estimate of 25,000.
What Risks Are People Concerned About
Authors: Fischer Gregory W. , Morgan M. Granger , Fischhoff Baruch , Nair Indira , Lave Lester B.
Published: May 2006

An unusual questionnaire was used to explore what risks concern laypeople. It asked respondents to list, in their own words, as many risks of personal concern as they could. They then selected the five risks of greatest concern and answered a set of specific questions about each. A coding scheme was developed for categorizing these responses and was shown to have good reliability. The questionnaire was administered to a heterogeneous convenience sample of subjects. They reported a very broad range of risks of concern, which differed in plausible ways as a function of their gender and age. Females and student‐age subjects were generally more concerned about the environment, whereas males and older subjects were more likely to mention health and safety risks. Both the extent of the risk‐reduction actions that they reported and their expressed willingness to pay for future risk reductions were greater for risk that presented a direct personal threat (e.g., health risks) than for risks that posed a diffuse threat to the environment or to people in general (e.g., pollution). Respondents perceived themselves as bearing primary responsibility for managing threats to their own health, but generally saw government as bearing a heavier responsibility for managing environmental risks (especially for pollutants) and war. The questionnaire instrument and coding structure developed for this work are well‐suited to a variety of future research applications. They provide a way to identify the risks that concern lay groups, as well as to track the evolution of those concerns over time.
Biological Basis of Chemical Carcinogenesis: Insights from Benzene
Authors: Cox Louis Anthony
Published: May 2006

Benzene is one of the best studied of the known human carcinogens. It causes leukemia in humans and a variety of solid tumors in rats and mice. Decades of research on benzene metabolism, pharmacokinetics, cytotoxicity, genotoxicity, and carcinogenicity in vivo and in vitro are starting to converge on a small set of overlapping hypotheses about the most probable biological mechanisms of benzene toxicity and carcinogenicity. Although there is still room for surprises, it seems likely that the ultimate answer to the mystery of how benzene exerts its multiple effects will consist of elaborations and extensions of one or more of the current hypotheses. This paper reviews benzene health effects and biology, showing how various aspects of metabolism and cytotoxicity fit together with genotoxic and nongenotoxic effects to help explain how benzene may cause cancer. Its goals are: (i) to introduce the qualitative biological background needed for detailed quantitative dose‐response modeling of benzene cancer risks; and (ii) to survey a rapidly evolving area of research that shows promise of producing fundamental insights into the mechanisms of toxicity and carcinogenesis for several chemicals–benzene and perhaps phenols, catechols, and other hydroxylated ring hydrocarbons–in the decade ahead.