bluuebunny/crossref_metadata_2025 huggingface dataset:
Perception and Acceptance of Technological and Environmental Risks: Why Are Poor Countries Less Concerned?
Authors: Sokolowska Joanna , Tyszka Tadeusz
Published: May 2006

The research has been aimed at answering two questions: (1) What factors impact perception and acceptance of technological and environmental hazards? (2) Why are rich societies involved more in protecting their environment and health than poor societies? Data has been collected from representative samples of two countries—Poland and Sweden. The results indicate that (1) contrary to earlier findings, the inverse relations between perceived benefits and dangers of hazards has not been observed, (2) acceptance of a risk has been mostly influenced by perceived benefits, (3) rejection of a risk has been mostly influenced by its perceived harmful consequences. Concerning the second question, it has been found that: (1) perceived hazard's danger and benefit is not the only factor that impacts its acceptance, and (2) a broader economic context can impact acceptance (tolerance) of hazards. It has been found that being aware of high dangers and not very high benefits of hazardous activities, Poles still have accepted them. Thus, Poles seem to follow an old proverb: “When one does not have what one likes, one has to like what one has.”
Consideration of Background Exposures in the Management of Hazardous Waste Sites: A New Approach to Risk Assessment
Authors: Smith Allan H. , Sciortino Stanley , Goeden Helen , Wright Catherine C.
Published: May 2006

The current approach to health risk assessment of toxic waste sites in the U.S. may lead to considerable expenditure of resources without any meaningful reduction in population exposure. Risk assessment methods used generally ignore background exposures and consider only incremental risk estimates for maximally exposed individuals. Such risk estimates do not address true public health risks to which background exposures also contribute. The purpose of this paper is to recommend a new approach to risk assessment and risk management concerning toxic waste sites. Under this new approach, which we have called public health risk assessment, chemical substances would be classified into a level of concern based on the potential health risks associated with typical national and regional background exposures. Site assessment would then be based on the level of concern for the particular pollutants involved and the potential contribution of site contaminants to typical background human exposures. While various problems can be foreseen with this approach, the key advantage is that resources would be allocated to reduce the most important sources of human exposure, and site remediation decisions could be simplified by focussing on exposure assessment rather than questionable risk extrapolations.
Risk Perception and Symptom Reporting
Authors: MacGregor Donald G. , Fleming Raymond
Published: May 2006

Public reaction to chemical technologies has included a perception that chemical exposure is a contributor to human health problems. Though these perceptions sometimes correspond with technical assessments of chemical risks, at other times they do not. This paper presents a descriptive model of the relationship between perception of one's health status and a set of factors that are used by individuals as part of causal reasoning about the meaning of somatic change. The model incorporates both personal events and experiences associated with somatic change (e.g., stress, sensory cues), as well as aspects of an individual's social context in which perceptions of chemical risks serve as a powerful framework for attributing meaning to chemical exposure. Within this model, the causal inferences that people make about the effects of chemical exposure on symptomatology are viewed as part of a natural, psychological adaptation in which the individual seeks to decrease their uncertainty about the factors or conditions that cause them to feel as they do.
The Role of Heavy Drinking in the Risk of Traffic Fatalities
Authors: Kennedy Bruce P. , Isaac Nancy E. , Graham John D.
Published: May 2006

Recent studies have identified a “hard core” of drinking drivers who do not fit a “social” drinker profile and may require medical intervention. This article builds on these studies by quantifying the role of heavy drinking in motor vehicle fatalities. Data on male alcohol‐involved fatally‐injured drivers (AIFIDs) were obtained from the U.S. Fatal Accident Reporting System (FARS) for the years 1989–1990 (n = 8876). The AIFIDs were grouped into either a “heavy” or “light” drinking category based on drinking behaviors inferred from prior driving records and blood alcohol concentrations (BAC). The majority of male AIFIDs were between the ages of 20–39 (70%). Sixty‐five percent had a BAC of 150 mg/dl or greater, and 41% had a BAC in excess of 200 mg/dl. AIFIDs with high BACs were more likely to have histories of DUI convictions and license suspensions than AIFIDs with low BACs. According to the study's criteria, 73% percent of the AIFIDs could be classified as “heavy” drinkers. There were no driving variables that differentiated the heavy and light drinker groups, indicating that heavy drinking per se is the primary factor that distinguishes the groups. Male alcohol‐involved fatally injured drivers are comprised mostly of heavy drinkers who may suffer from serious drinking problems or alcoholism. Successful interventions may require medical treatment as well as punitive criminal justice policies.
Variance‐Based Importance Analysis Applied to a Complex Probabilistic Performance Assessment
Authors: Manteufel Randall D.
Published: May 2006

The most important input parameters in a complex probabilistic performance assessment are identified using a variance‐based method and compared with those identified using a regression‐based method. The variance‐based method has the advantage of not requiring assumptions about the functional relationship between input and output parameters. However, it has the drawback of requiring heuristic assessments of threshold variance ratios above which a parameter is considered important, and it also requires numerous executions of the computer program, which may be computationally expensive. Both methods identified the same top 5 and 7 of the top 10 most important parameters for a system having 195 inputs. Although no distinct advantage for the variance‐based approach was identified, the ideas which motivate the new approach are sound and suggest new avenues for exploring the relationships between the inputs and the output of a complex system.
Bounding Estimates for Critical Events When Directly Disposing Highly Enriched Spent Nuclear Fuel in Unsaturated Tuff
Authors: Rechard Rob P. , Tierney Martin S. , Sanchez Larry C. , Martell Mary‐Alena
Published: May 2006

This paper examines the possibility of criticality in a nuclear waste repository. The estimated probabilities are rough bounds and do not entirely dismiss the possibility of a critical condition; however, they do point to the difficulty of creating conditions under which a critical mass could be assembled (i.e., corrosion of containers, separation of neutron absorbers from the fissile material, and collapse or precipitation of the fissile material). In addition, should a criticality occur in or near a container, the bounding consequence calculations showed that fissions from one critical event are quite small (<˜1020 fissions, if similar to aqueous and metal accidents and experiments). Furthermore, a reasonable upper bound of total critical events of 1028 fissions corresponds to only 0.1% of the number of fissions represented by the spent nuclear fuel inventory in a repository containing 70,000 metric tons of heavy metal (MTHM) (the expected size for the proposed repository at Yucca Mountain, Nevada).
Remedial Policies in Radiologically‐Contaminated Forests: Environmental Consequences and Risk Assessment
Authors: Linkov Igor , Morel Benoit , Schell William R.
Published: May 2006

As a result of the Chernobyl nuclear power plant accident in 1986, large forested areas in Europe were contaminated by radionuclides. Extensive societal pressure has been exerted to decrease the radiation dose to the population and to the environment. Thus, in making abatement and remediation policy decisions not only economic costs, but also human and environmental risk assessment are desired. Forest remediation by organic layer removal, one of the most promising cleanup policies, is considered in this paper. Ecological risk assessment requires evaluation of the radionuclide distribution in forests. The FORESTPATH model(1,2) is used for predicting the radionuclide fate in forest compartments after deposition as well as for evaluating the application of the remedial policy. Time of intervention and radionuclide deposition profile was predicted as being crucial for the remediation efficiency. Risk assessment conducted for a critical group of forest users in Belarus shows that consumption of forest products (berries and mushrooms) leads to about 0.004% risk of a fatal cancer. Cost‐benefit analysis for forest cleanup suggests that complete removal of organic layer is too expensive for application in Belarus.
Importance of Distributional Form in Characterizing Inputs to Monte Carlo Risk Assessments
Authors: Haas Charles N.
Published: May 2006

The selection among distributional forms for inputs into uncertainty and variability (e.g., Monte Carlo) analyses is an important task. This paper considers the importance of distributional selection by examining the overall and tail behavior of the lognormal, Weibull, gamma, and inverse gaussian distributions. It is concluded that at low relative standard deviation (below 1), there is less of a difference between upper tail behavior among the distributions than at higher RSD values. Sample sizes in excess of 200 are required to reliably distinguish between distributional forms at the higher RSD values. The likelihood statistic appears to offer a reasonable approach to distributional discrimination, and it, or a similar approach, should be incorporated into distributional fitting procedures used in risk analysis.
Air Pollution and Human Health: Perspectives for the ‘90s and Beyond
Authors: Lipfert Frederick W.
Published: May 2006

This paper considers the health effects of air pollution from three perspectives: historical, statistical, and public policy, and also as depicted by the recent epidemiology, primarily mortality studies. The historical perspectives establish the reality of population‐based health effects, and they provide data with which to evaluate more recent evidence. Statistical perspectives imply that, while there is strong evidence that associations between air quality and health persist, many details of these relationships remain obscure, especially as to the existence of concentration thresholds that might define safe exposure levels. Additional major questions include the effects of uncertainties in actual pollution exposures, the degree of prematurity of “excess” deaths, and whether the development of new cases of chronic disease is associated with air pollution. Public policy issues center around interpreting the new epidemiological studies in the light of these uncertainties and the analysis and management of the concomitant health risks.
Hazardous Materials Releases in the Northridge Earthquake: Implications for Seismic Risk Assessment
Authors: Lindell Michael K. , Perry Ronald W.
Published: May 2006

In recent years, increasing attention has been given to the problem of earthquake‐initiated hazardous materials releases (EIHRs). While the evidence indicates that EHIRs are an important part of the earthquake hazard profile, little attention has been given to documenting them in a way that could form the basis for more systematic estimates of their probability and consequences. Data from the January 17, 1994 Northridge earthquake document the range and nature of hazardous materials events in the impact area, including those at fixed‐site facilities and in transportation systems. Proportional estimates of hazmat incidence are provided, and the implications of these data for developing risk assessments and earthquake hazard management are discussed.
Compliance Versus Risk in Assessing Occupational Exposures
Authors: Tornero‐Velez Rogelio , Symanski Elaine , Kromhout Hans , Yu Rong C. , Rappaport Stephen M.
Published: May 2006

Assessments of occupational exposures to chemicals are generally based upon the practice of compliance testing in which the probability of compliance is related to the exceedance [γ, the likelihood that any measurement would exceed an occupational exposure limit (OEL)] and the number of measurements obtained. On the other hand, workers’ chronic health risks generally depend upon cumulative lifetime exposures which are not directly related to the probability of compliance. In this paper we define the probability of “overexposure” (θ) as the likelihood that individual risk (a function of cumulative exposure) exceeds the risk inherent in the OEL (a function of the OEL and duration of exposure). We regard θ as a relevant measure of individual risk for chemicals, such as carcinogens, which produce chronic effects after long‐term exposures but not necessarily for acutely‐toxic substances which can produce effects relatively quickly. We apply a random‐effects model to data from 179 groups of workers, exposed to a variety of chemical agents, and obtain parameter estimates for the group mean exposure and the within‐ and between‐worker components of variance. These estimates are then combined with OELs to generate estimates of γ and θ. We show that compliance testing can significantly underestimate the health risk when sample sizes are small. That is, there can be large probabilities of compliance with typical sample sizes, despite the fact that large proportions of the working population have individual risks greater than the risk inherent in the OEL. We demonstrate further that, because the relationship between θ and γ depends upon the within‐ and between‐worker components of variance, it cannot be assumed a priori that exceedance is a conservative surrogate for overexposure. Thus, we conclude that assessment practices which focus upon either compliance or exceedance are problematic and recommend that employers evaluate exposures relative to the probabilities of overexposure.
Risk Perception, Federal Spending, and the Savannah River Site: Attitudes of Hunters and Fishermen
Authors: Burger Joanna , Sanchez Jessica , Gibbons J. Whitfield , Gochfeld Michael
Published: May 2006

This paper examines the attitudes of 285 hunters and fishermen from South Carolina about hunting and fishing, risk, environmental issues, and future land use of the Savannah River Site. We test the null hypothesis that there is no difference in hunting and fishing rates, attitudes toward the safety of fish and deer obtained from SRS, attitudes toward future land use at SRS, and perceptions of the severity of environmental problems as a function of how far respondents lived from the site. Respondents hunted or fished an average of over 40 days a year, and only half felt that the fish and deer from SRS were safe to eat. Willingness to expend federal funds was correlated with perceptions of the severity of the problem. Preferences for future land use at SRS fell into three categories: high (environmental research park, hunting, fishing, camping), medium (nuclear production, factories, preserve only), and low (nuclear waste storage, residential). There were no differences in hunting and fishing rates, ranking of the severity of environmental problems, and willingness to expend federal funds as a function of distance of residence from SRS, but attitudes toward future land use differed significantly as a function of location of residence. Those living close to SRS were more willing to have the site used for factories, residential, nuclear material production and to store nuclear wastes than those living farther from the site. Our data on recreational rates, attitudes toward future land use, and willingness to expend federal funds to solve environmental problems reiterate the importance of assessing stakeholder attitudes toward decisions regarding future land use at DOE sites
Estimation from Zero‐Failure Data
Authors: Bailey Robert T.
Published: May 2006

When performing quantitative (or probabilistic) risk assessments, it is often the case that data for many of the potential events in question are sparse or nonexistent. Some of these events may be well‐represented by the binomial probability distribution. In this paper, a model for predicting the binomial failure probability,P, from data that include no failures is examined. A review of the literature indicates that the use of this model is currently limited to risk analysis of energetic initiation in the explosives testing field. The basis for the model is discussed, and the behavior of the model relative to other models developed for the same purpose is investigated. It is found that the qualitative behavior of the model is very similar to that of the other models, and for larger values ofn(the number of trials), the predictedPvalues varied by a factor of about eight among the five models examined. Analysis revealed that the estimator is nearly identical to the median of a Bayesian posterior distribution, derived using a uniform prior. An explanation of the application of the estimator in explosives testing is provided, and comments are offered regarding the use of the estimator versus other possible techniques.
Statistical Quantification of the Sources of Variance in Uncertainty Analyses
Authors: Robinson R. Bruce , Hurst Brian T.
Published: May 2006

A statistical method using linear regression is shown for quantifying each variable's contribution to the uncertainty analysis in environmental health risk assessments. The method suggests that uncertainty analyses can be significantly simplified when a linear relationship can be established between risk or log(risk) and the independent variables.
The Environmental Geochemistry and Bioaccessibility of Mercury in Soils and Sediments: A Review
Authors: Davis Andy , Bloom Nicolas S. , Que Hee Shane S.
Published: May 2006

There have been many studies of mercury geochemistry in the environment and its bioconcentration/bioaccumulation through the aquatic food chain. However, there is a dearth of information regarding the bioaccessibility of mercury in human receptors exposed primarily by soil ingestion. This paper reviews the current state of knowledge of mercury bioaccessibility and speciation in soils, and the utility of speciation methods to estimate mercury bioaccessibility. We conclude that additional research is necessary to determine: (1) whether analytical measurements can adequately determine the bioaccessibility of mercury in sediments and soils; (2) the accuracy of in vitro analyses in assessing mercury bioaccessibility; (3) the ability of mercury to cross tissue membranes of the mouth, esophagus, stomach, and the small and large intestines; (4) the speciation and distribution of mercury in biological fluids; and (5) mercury bioavailability using an in vivo animal model relevant to human gastrointestinal tract conditions.
The Effect of Decisions About Spent Nuclear Fuel Storage on Residential Property Values
Authors: Metz William C. , Clark David E.
Published: May 2006

National, regional, state, and local surveys have revealed that people have intensely negative images of “nuclear” and “radioactive” technologies, activities, and facilities, as well as associated fears of stigmatization. In light of these perceptions, the debate over where to temporarily store or permanently dispose of spent nuclear fuel (at the reactor site, an interim storage facility, or a permanent repository) provokes immense concern among possible host jurisdictions. To address these concerns, one needs to know if people's subjective opinions conform with the choices they make and are therefore reflected in their economic behavior. Argonne National Laboratory researchers used a hedonic model to complete a study of residential property value dynamics over a 5‐year period within a 15‐mile radius of two California nuclear power plants. They tracked the economic ramifications of decisions about the spent nuclear fuel stored at those reactors. The study revealed that no significant negative effects on residential property values resulted from a decision to move spent nuclear fuel from wet storage to a dry‐cask storage facility or from a request to extend the reactor operating permit (given future changes in the type of nuclear fuel storage facility that would accompany such an extension).
Biosphere Model for High Level Waste Repository
Authors: Barrdahl Runo
Published: May 2006

Method for environmental impact modeling involving uncertainty, overcoming the disadvantage of providing only one upper bound based on accumulated effects from all extreme events. This method provides a suite of upper and lower bounds based on any subset of such extreme events, to be chosen among by the decision maker.
Projection of Health Benefits from Ambient Ozone Reduction Related to the Use of Methyl tertiary Butyl Ether (MTBE) in the Reformulated Gasoline Program
Authors: Erdal Serap , Gong Henry , Linn William S. , Rykowski Richard
Published: May 2006

To estimate potential public health benefits from ozone (O3) pollution reduction attributable to the use of methyl tertiary‐butyl ether (MTBE) in gasoline, O3 dose‐response estimates from the biomedical literature were combined with model estimates of O3 reduction. Modeling employed EPA MOBILE5a and Complex models to predict emission changes, industry AQIRP techniques to predict ambient O3 changes, and the National Exposure Model to predict human exposures. Human health effects considered were lung function decrements and respiratory irritant symptoms (using dose‐response functions measured in laboratory and field studies), and increased death rates (using concentration‐response functions inferred statistically from public‐health data). Other reported health effects, such as lung inflammation, increases in asthma attacks, and hospitalizations, were not addressed because of inadequate dose‐response information. Even for the health responses considered, quantitation of improvements due to MTBE use is problematical, because MTBE affects only a small percentage of existing O3 pollution, and because exposure‐response relationships are not well understood for population subgroups most likely to be affected. Nevertheless, it is reasonable to conclude that even small MTBE‐associated reductions in peak ambient O3 levels (1–5 ppb, according to model estimates) should yield considerable public health benefits. Tens of millions of Americans are potentially exposed to O3 in the concentration range associated with health effects. Even if only a small percentage of them are susceptible, any incremental reduction in O3 (as with MTBE use) must mitigate or prevent effects for a meaningful number of people. Better quantitative estimates of benefit must await a more detailed understanding of each link in the chain of causation.
Route‐to‐Route Extrapolation of the Toxic Potency of MTBE
Authors: Dourson Michael L. , Felter Susan P.
Published: May 2006

MTBE is a volatile organic compound used as an oxygenating agent in gasoline. Inhalation from fumes while refueling automobiles is the principle route of exposure for humans, and toxicity by this route has been well studied. Oral exposures to MTBE exist as well, primarily due to ground‐water contamination from leaking stationary sources, such as underground storage tanks. Assessing the potential public health impacts of oral exposures to MTBE is problematic because drinking water studies do not exist for MTBE, and the few oil‐gavage studies from which a risk assessment could be derived are limited. This paper evaluates the suitability of the MTBE database for conducting an inhalation route‐to‐oral route extrapolation of toxicity. This includes evaluating the similarity of critical effect between these two routes, quantifiable differences in absorption, distribution, metabolism, and excretion, and sufficiency of toxicity data by the inhalation route. We conclude that such an extrapolation is appropriate and have validated the extrapolation by finding comparable toxicity between a subchronic gavage oral bioassay and oral doses we extrapolate from a subchronic inhalation bioassay. Our results are extended to the 2‐year inhalation toxicity study by Chun et al. (1992) in which rats were exposed to 0, 400, 3000, or 8000 ppm MTBE for 6 hr/d, 5 d/wk. We have estimated the equivalent oral doses to be 0, 130, 940, or 2700 mg/kg/d. These equivalent doses may be useful in conducting noncancer and cancer risk assessments.
Risk Characterization of Methyl tertiary Butyl Ether (MTBE) in Tap Water
Authors: Stern Bonnie R. , Tardiff Robert G.
Published: May 2006

Methyl tertiary butyl ether (MTBE) can enter surface water and groundwater through wet atmospheric deposition or as a result of fuel leaks and spills. About 30% of the U.S. population lives in areas where MTBE is in regular use. Ninety‐five percent of this population is unlikely to be exposed to MTBE in tap water at concentrations exceeding 2 ppb, and most will be exposed to concentrations that are much lower and may be zero. About 5% of this population may be exposed to higher levels of MTBE in tap water, resulting from fuel tank leaks and spills into surface or groundwater used for potable water supplies. This paper describes the concentration ranges found and anticipated in surface and groundwater, and estimates the distribution of doses experienced by humans using water containing MTBE to drink, prepare food, and shower/bathe. The toxic properties (including potency) of MTBE when ingested, inhaled, and in contact with the skin are summarized. Using a range of human toxic potency values derived from animal studies, margins of exposure (MOE) associated with alternative chronic exposure scenarios are estimated to range from 1700 to 140,000. Maximum concentrations of MTBE in tap water anticipated not to cause adverse health effects are determined to range from 700 to 14,000 ppb. The results of this analysis demonstrate that no health risks are likely to be associated with chronic and subchronic human exposures to MTBE in tap water. Although some individuals may be exposed to very high concentrations of MTBE in tap water immediately following a localized spill, these exposures are likely to be brief in duration due to large‐scale dilution and rapid volatilization of MTBE, the institution of emergency response and remediation measures to minimize human exposures, and the low taste and odor thresholds of MTBE which ensure that its presence in tap water is readily detected at concentrations well below the threshold for human injury.
Estimating Benchmark Concentrations and Other Noncancer Endpoints in Epidemiology Studies
Authors: Bailer A. J. , Stayner L. T. , Smith R. J. , Kuempel E. D. , Prince M. M.
Published: May 2006

Methods for evaluating the hazards associated with noncancer responses with epidemiologic data are considered. The methods for noncancer risk assessment have largely been developed for experimental data, and are not always suitable for the more complex structure of epidemiologic data. In epidemiology, the measurement of the response and the exposure is often either continuous or dichotomous. For a continuous noncancer response modeled with multiple regression, a variety of endpoints may be examined: (1) the concentration associated with absolute or relative decrements in response; (2) a threshold concentration associated with no change in response; and (3) the concentration associated with a particular added risk of impairment. For a dichotomous noncancer response modeled with logistic regression, concentrations associated with specified added/extra risk or with a threshold responses may be estimated. No‐observed‐effect concentrations may also be estimated for categorizations of exposures for both continuous and dichotomous responses but these may depend on the arbitrary categories chosen. Respiratory function in miners exposed to coal dust is used to illustrate these methods.
Risk Analysis and Management of Dam Safety
Authors: Lave Lester B. , Balvanyos Tunde
Published: May 2006

The current safety criteria for a high hazard dam focus on protecting the dam during a large flood. While protecting the dam does help to protect downstream people and property, the two objectives are not the same. Instead, the criteria should focus on lowering property damage (including damage to the dam) and preventing flood deaths.

High hazard dams must survive a design flood in the current safety criteria. However, experts don't agree on the size of the peak flow that meets this criteria.

Statistical hydrologists have proposed an alternative to using professional judgment to specify the design flood. Unfortunately, peak flow distributions cannot be estimated with confidence for extreme floods given available data.

A major safety goal is to prevent deaths from floods. Preventing deaths is a major reason for constructing the spillway to handle extreme floods so that the dam doesn't fail due to overtopping. However, even if the dam doesn't fail, the spilled floods could cause many deaths. A better approach is to warn people to get them out of harm's way if a flood is coming.

Retrofitting existing dams that could pass a “probable maximum flood” (PMF) when built is almost never a good use of funds. Instead, funds would be spent better by focusing on preventing damage from small floods, lowering the damage from medium‐sized floods, and warning people in the event of a flood that could pose risks to life.
A Methodology to Select a Wire Insulation for Use in Habitable Spacecraft
Authors: Paulos Todd , Apostolakis George
Published: May 2006

This paper investigates electrical overheating events aboard a habitable spacecraft. The wire insulation involved in these failures plays a major role in the entire event scenario from threat development to detection and damage assessment. Ideally, if models of wire overheating events in microgravity existed, the various wire insulations under consideration could be quantitatively compared. However, these models do not exist. In this paper, a methodology is developed that can be used to select a wire insulation that is best suited for use in a habitable spacecraft. The results of this study show that, based upon the Analytic Hierarchy Process and simplifying assumptions, the criteria selected, and data used in the analysis, Tefzel is better than Teflon for use in a habitable spacecraft.
An Approach to Vulnerability Analysis of Complex Industrial Systems
Authors: Einarsson Stefän , Rausand Marvin
Published: May 2006

The concept of vulnerability of complex industrial systems is defined and discussed in relation to risk and system survivability. The discussion is illustrated by referring to a number of previous industrial accidents. The various risk factors, or threats, influencing an industrial system's vulnerability are classified and discussed. Both internal and external threats are covered. The general scope of vulnerability analysis is compared to traditional risk analysis approaches and main differences are illustrated. A general procedure for vulnerability analysis in two steps, including building of scenarios and preparation of relevant worksheets, is described and discussed.
Expert Informants and Relative Risk: A Methodology for Modeling Waterways1
Authors: Gramling Robert , Forsyth Craig J. , Wooddell George
Published: May 2006

This project describes a methodology for assessing relative risk along a transportation corridor utilizing waterborne transportation on the busiest port area in the world, the lower Mississippi River (from the mouth of Southwest Pass up through Baton Rouge, Louisiana). The paper calculates a relative risk scale, using data obtained from maritime experts, previous research, and existing databases. The research aggregates the vessel traffic data and geographic risk location data to produce relative risk scores for each mile along the River from the mouth of Southwest Pass to the termination of shipping at the U.S. 190 bridge across the River at Baton Rouge. This is done in a very simple and practical way for this initial model: (1) each vessel traveling the Mississippi is classified according to its risk potential for those miles that it passes in route to where it docks, and (2) points along the river are assigned a relative risk score based upon risk variables identified by expérts identified through a standard sampling procedure. The relative risk scores for river miles are combinations of these two factors.
A Risk Assessment for Consumers of Mourning Doves
Authors: Burger Joanna , Kennamer Robert A. , Brisbin I. Lehr , Gochfeld Michael
Published: May 2006

Recreational and subsistence hunters and anglers consume a wide range of species, including birds, mammals, fish and shellfish, some of which represent significant exposure pathways for environmental toxic agents. This study focuses on the Department of Energy's (DOE'S) Savannah River Site (SRS), a former nuclear weapons production facility in South Carolina. The potential risk of contaminant intake from consuming mourning doves (Zenaida macroura), the most popular United States game bird, was examined under various risk scenarios. For all of these scenarios we used the mean tissue concentration of six metals (lead, mercury, cadmium, selenium, chromium, manganese) and radiocesium, in doves collected on and near SRS. We also estimated risk to a child consuming doves that had the maximum contaminant level. We used the cancer slope factor for radiocesium, the Environmental Protection Agencies UptakeBiokinetic model for lead, and published reference doses for the other metals. As a result of our risk assessments we recommend management of water levels in contaminated reservoirs so that lake bed sediments are not exposed to use by gamebirds and other terrestrial wildlife. Particularly, measures should be taken to insure that the hunting public does not have access to such a site. Our data also indicate that doves on popular hunting areas are exposed to excess lead, suggesting that banning lead shot for doves, as has been done for waterfowl, is desirable.
Retrospective Temporal and Spatial Mobility of Adult Iowa Women
Authors: Field R. William , Smith Brian J. , Brus Christine P. , Lynch Charles F. , Neuberger John S. , Steck Daniel J.
Published: May 2006

Human exposure assessments require a linkage between toxicant concentrations in occupied spaces and the receptor's mobility pattern. Databases reporting distinct populations' mobility in various parts of the home, time outside the home, and time in another building are scarce. Temporal longitudinal trends in these mobility patterns for specific age and gender groups are nonexistent. This paper describes subgroup trends in the spatial and temporal mobility patterns within the home, outside the home, and in another building for 619 Iowa females that occupied the same home for at least 20 years. The study found that the mean time spent at home for the participants ranged from a low of 69.4% for the 50‐59 year age group to a high of 81.6% for the over 80‐year‐old age group. Participants who lived in either one‐ or two‐ story homes with basements spent the majority of their residential occupancy on the first story. Trends across age varied for other subgroups by number of children, education, and urbadrural status. Since all of these trends were nonlinear, they indicate that error exists when assuming a constant, such as a 75% home occupancy factor, which has been advocated by some researchers and agencies. In addition, while aggregate data, such as presented in this report, are more helpll in deriving risk estimates for population subgroups, they cannot supplant good individual‐level data for determining risks.
A Quantitative Test of the Cultural Theory of Risk Perceptions: Comparison with the Psychometric Paradigm
Authors: Marris Claire , Langford Ian H. , O'Riordan Timothy
Published: May 2006

This paper seeks to compare two frameworks which have been proposed to explain risk perceptions, namely, cultural theory and the psychometric paradigm. A structured questionnaire which incorporated elements from both approaches was administered to 129 residents of Norwich, England. The qualitative risk characteristics generated by the psychometric paradigm explained a far greater proportion of the variance in risk perceptions than cultural biases, though it should be borne in mind that the qualitative characteristics refer directly to risks whereas cultural biases are much more distant variables. Correlations between cultural biases and risk perceptions were very low, but the key point was that each cultural bias was associated with concern about distinct types of risks and that the pattern of responses was compatible with that predicted by cultural theory. The cultural approach also provided indicators for underlying beliefs regarding trust and the environment; beliefs which were consistent within each world view but divergent between them. An important drawback, however, was that the psychometric questionnaire could only allocate 32% of the respondents unequivocally to one of the four cultural types. The rest of the sample expressed several cultural biases simultaneously, or none at all. Cultural biases are therefore probably best interpreted as four extreme world views, and a mixture of qualitative and quantitative research methodologies would generate better insights into who might defend these views in what circumstances, whether there are only four mutually exclusive world views or not, and how these views are related to patterns of social solidarity, and judgments on institutional trust.
Lognormal Distributions for Skin Area as a Function of Body Weight1
Authors: Burmaster David E.
Published: May 2006

This paper reanalyzes the dataset cited by the U.S. Environmental Protection Agency in its Exposure Factors Handbook that contains measurements of skin area, height, and body weight for 401 people spanning all stages of development. The reanalysis shows that a univariate model for total skin area as a function of body weight gives useful and practical results with little or no loss of reliability as compared to the Agency's bivariate model. This new result leads to a new method to develop Lognormal distributions for total skin area as a function of body weight alone.
Methodological Approaches to Assessing Risk Perceptions Associated with Food‐Related Hazards
Authors: Frewer Lynn J. , Howard Chaya , Hedderley Duncan , Shepherd Richard
Published: May 2006

The psychometric approach developed by Slovic and his co‐workers has been effectively used to assess risk perceptions associated with different food‐related hazards. However, further examination (using questionnaire data and partial correlation techniques) has indicated that technological hazards are highly differentiated from lifestyle hazards, in terms of both hazard control and knowledge about the hazard. Optimistic bias was also seen to vary between hazards. Further research has focused on a particular hazard, genetic engineering. Risk perceptions associated with genetic engineering are underpinned by ethical concern and questions relating to perceived need for the technology, as well as perceptions of risk or harm. However, increasing the specificity of hazard stimuli was found to alter the factor structure of underlying risk perceptions. The utility of preference mapping procedures in determining individual differences in trust in risk regulators is also discussed.
Information and Risk Perception: A Dynamic Adjustment Process
Authors: Liu Shiping , Huang Ju‐Chin , Brown Gregory L.
Published: May 2006

It is common in catastrophic food‐contamination events that consumers fail to adjust instantaneously to a normal consumption level. One explanation is that consumers only gradually accept new positive information as being trustworthy. The gradual establishment of the trustworthiness of the released information depends on both positive and negative media coverage over time. We examine the individual “trust” effects by extending the prospective reference theory (Viscusi, 1989) to include a dynamic adjustment process of risk perception. Conditions that allow aggregation of changes in risk perceptions across individuals are described. The proposed model describes a general updating process of risk perceptions to media coverage and can be applied to explain the temporal impact of media coverage on consumption of a broad range of goods (food or nonfood). A case study of milk contamination is conducted to demonstrate consumer demand adjustment process to a temporarily unfavorable shock. The results suggest that effects of positive and negative information to adjustment of consumption and risk perception are asymmetric over time.
Gender Differences in Risk Perception: Theoretical and Methodological erspectives
Authors: Gustafsod Per E.
Published: May 2006

A substantial body of risk research indicates that women and men differ in their perceptions of risk. This paper discusses how they differ and why. A review of a number of existing empirical studies of risk perception points at several problems, regarding what gender differences are found in such studies, and how these differences are accounted for. Firstly, quantitative approaches, which have so far dominated risk research, and qualitative approaches give different, sometimes even contradictory images of women's and men's perceptions of risk. Secondly, the gender differences that appear are often left unexplained, and even when explanations are suggested, these are seldom related to gender research and gender theory in any systematic way. This paper argues that a coherent, theoretically informed gender perspective on risk is needed to improve the understanding of women's and men's risk perceptions. An analysis of social theories of gender points out some relations and distinctions which should be considered in such a perspective. It is argued that gender structures, reflected in gendered ideology and gendered practice, give rise to systematic gender differences in the perception of risk. These gender differences may be of different kinds, and their investigation requires the use of qualitative as well as quantitative methods. In conclusion, the arguments about gender and risk perception are brought together in a theoretical model which might serve as a starting point for further research.
Beliefs and the Perception of Risks and Accidents
Authors: Kouabenan Dongo Rémi
Published: May 2006

Identifying the causes of accidents is a necessary prerequisite for preventive action. Some research suggests however that the analysis of accidents does not only differ between experts and laymen but that it is also linked to certain characteristics inherent in the analyst and in the social group to which he belongs: beliefs, value systems, norms, experiences in common, attitudes, roles, social and technical practices, etc. Culturally determined bias seems to affect the perception of risk and the causes of accidents. This article presents a certain number of thoughts and results based upon research carried out on causal attributions of traffic accidents in The Ivory Coast (West Africa) and discusses the importance of culture in risk‐taking and accident prevention. It shows in particular that fatalistic beliefs and mystical practices influence the perception of accidents and consequently incite one to take more risks and neglect safety measures.
On Summarizing Group Exposures in Risk Assessment: Is an Arithmetic Mean or a Geometric Mean More Appropriate?
Authors: Crump Kenny S.
Published: May 2006

Since substantial bias can result from assigning some type of mean exposure to a group, risk assessments based on epidemiological data should avoid the grouping of data whenever possible. However, ungrouped data are frequently unavailable, and the question arises as to whether an arithmetic or geometric mean is the most appropriate summary measure of exposure. It is argued in this paper that one should use the type of mean for which the total risk that would result if every member of the population was exposed to the mean level is as close as possible to the actual total population risk. Using this criterion an arithmetic mean is always preferred over a geometric mean whenever the dose response is convex. In each of several data sets examined in this paper for which the dose response was not convex, an arithmetic mean was still preferred based on this criterion.
Topics in Microbial Risk Assessment: Dynamic Flow Tree Process
Authors: Marks Harry M. , Coleman Margaret E. , Lin C.‐T. Jordan , Roberts Tanya
Published: May 2006

Microbial risk assessment is emerging as a new discipline in risk assessment. A systematic approach to microbial risk assessment is presented that employs data analysis for developing parsimonious models and accounts formally for the variability and uncertainty of model inputs using analysis of variance and Monte Carlo simulation. The purpose of the paper is to raise and examine issues in conducting microbial risk assessments. The enteric pathogen Escherichia coli O157:H7 was selected as an example for this study due to its significance to public health. The framework for our work is consistent with the risk assessment components described by the National Research Council in 1983 (hazard identification; exposure assessment; dose‐response assessment; and risk characterization). Exposure assessment focuses on hamburgers, cooked a range of temperatures from rare to well done, the latter typical for fast food restaurants. Features of the model include predictive microbiology components that account for random stochastic growth and death of organisms in hamburger. For dose‐response modeling, Shigella data from human feeding studies were used as a surrogate for E. coli O157:H7. Risks were calculated using a threshold model and an alternative nonthreshold model. The 95% probability intervals for risk of illness for product cooked to a given internal temperature spanned five orders of magnitude for these models. The existence of even a small threshold has a dramatic impact on the estimated risk.
Stochastic Response Surface Methods (SRSMs) for Uncertainty Propagation: Application to Environmental and Biological Systems
Authors: Isukapalli S. S. , Roy A. , Georgopoulos P. G.
Published: May 2006

Comprehensive uncertainty analyses of complex models of environmental and biological systems are essential but often not feasible due to the computational resources they require. “Traditional” methods, such as standard Monte Carlo and Latin Hypercube Sampling, for propagating uncertainty and developing probability densities of model outputs, may in fact require performing a prohibitive number of model simulations. An alternative is offered, for a wide range of problems, by the computationally efficient “Stochastic Response Surface Methods (SRSMs)” for uncertainty propagation. These methods extend the classical response surface methodology to systems with stochastic inputs and outputs. This is accomplished by approximating both inputs and outputs of the uncertain system through stochastic series of “well behaved” standard random variables; the series expansions of the outputs contain unknown coefficients which are calculated by a method that uses the results of a limited number of model simulations. Two case studies are presented here involving (a) a physiologically‐based pharmacokinetic (PBPK) model for perchloroethylene (PERC) for humans, and (b) an atmospheric photochemical model, the Reactive Plume Model (RPM‐IV). The results obtained agree closely with those of traditional Monte Carlo and Latin Hypercube Sampling methods, while significantly reducing the required number of model simulations.