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At least 19 recordsLinked to original sources
PubMed1995

Human tissue monitoring and specimen banking: opportunities for exposure assessment, risk assessment, and epidemiologic research.

A symposium on Human Tissue Monitoring and Specimen Banking: Opportunities for Exposure Assessment, Risk Assessment, and Epidemiologic Research was held from 30 March to 1 April 1993 in Research Triangle Park, North Carolina. There were 117 registered participants from 18 states and 5 foreign countries. The first 2 days featured 21 invited speakers from the U.S. Environmental Protection Agency, the Centers for Disease Control and Prevention, the National Institute of Environmental Health Sciences, various other government agencies, and universities in the United States, Canada, Germany, and Norway. The speakers provided a state-of-the-art overview of human exposure assessment techniques (especially applications of biological markers) and their relevance to human tissue specimen banking. Issues relevant to large-scale specimen banking were discussed, including program design, sample design, data collection, tissue collection, and ethical ramifications. The final group of presentations concerned practical experiences of major specimen banking and human tissue monitoring programs in the United States and Europe. The symposium addressed the utility and research opportunities afforded by specimen banking programs for future research needs in the areas of human exposure assessment, risk assessment, and environmental epidemiology. The third day of the symposium consisted of a small workshop convened to discuss and develop recommendations to the U.S. Environmental Protection Agency regarding applications and utility of large-scale specimen banking, biological monitoring, and biological markers for risk assessment activities.

Biomarkers↗
PubMed1999

Assessing risk for violence among psychiatric patients: the HCR-20 violence risk assessment scheme and the Psychopathy Checklist: Screening Version.

This study evaluated the predictive validity of the HCR-20 (Historical, Clinical, and Risk Management) violence risk assessment scheme and the Psychopathy Checklist: Screening Version (PCL:SV). Files of 193 civilly committed patients were coded. Patients were followed up in the community for an average of 626 days. Receiver operating characteristic analyses with the HCR-20 yielded strong associations with violence (areas under curve [AUCs] = .76-.80). Persons scoring above the HCR-20 median were 6 to 13 times more likely to be violent than those scoring below the median. PCL:SV AUCs were more variable (.68-.79). Regression analyses revealed that the HCR-20 added incremental validity to the PCL:SV and that only HCR-20 subscales predicted violence. Implications for risk assessment research, and the clinical assessment and management of violence, are discussed.

Adult↗
PubMedDate not supplied

Ecological risk assessment: risk for what? How do we decide?

Ecological risk assessment is defined both in theory and in practice. To do it properly, we need to know what targets we are protecting, but these targets are not always obvious and clearly defined. The pragmatic approach, used most generally in the context of environmental protection legislation, is the risk quotient method. Two other approaches involving more transparency and ecological relevance are critically assessed. One is based on species sensitivity distributions; the other is based on generalized population dynamics. Challenges for the future are considered.

Ecology↗
PubMed1997

[Expert systems in risk assessment. Risk or opportunity?].

Experts underwriting systems in the risk selection of individual life insurance have a high place value and are, in future, indispensable in the daily underwriting process. The chance to reduce drastically dual operations enables the insurance companies to make more cost-efficient underwriting decisions. The rapidly advancing technology develops not only new dimensions for individualism and for providing customer service but also for a fast underwriting process which is of great benefit to the insurers who are up against stiff competition. The qualified underwriter and the physician will be relieved of standard work and have more time in investing their knowledge and know-how in the underwriting process which calls for an absolutely individual reflection. New activities are inevitably ahead of this group of persons: Maintenance and attendance of the experts system! A task with which the quality of such a system stands and falls. We are expectant to see what the future has in store for this field.

Artificial Intelligence↗
PubMed2002

Industrial solvents and liver toxicity: risk assessment, risk factors and mechanisms.

Organic solvents utilized in various industrial processes may be associated with hepatotoxicity. The hepatotoxicity of some of the solvents was recognized as early as 1887, 1889 and 1904. Factors contributing to the hepatotoxicity of solvents include 1) species differences, 2) liver blood flow, 3) protein binding, 4) point of binding intracellularly, 5) genetic factors, 6) different cellular enzymatic degradation, 7) age, 8) nutritional condition, 9) interaction with alcohol, and 10) interaction with medications of use and abuse. The hepatotoxicity of solvents in general and of carbon tetrachloride, trichloroethylene, tetrachloroethylene, toluene, and 1,1,1-trichloroethene are discussed. Experimental animal data, human data, and in vitro studies are explored. Suggested mechanisms of direct toxicity, indirect toxicity and autoimmune mechanisms are elaborated. The most important message from this review is that laboratory testing that is commonly used by clinicians to detect liver toxicity may not be sensitive enough to detect early liver hepatotoxicity from industrial solvents and new methodologies are being encouraged and utilized in the early recognition and diagnosis of hepatotoxicity for solvents. The final clinical assessment of hepatotoxicity and industrial solvents must take into account synergism with medications, drugs of use and abuse, alcohol, age, and nutrition. Early recognition and reporting will be helpful in further understanding the incidence, cofactors and possible mechanisms.

Animals↗
PubMed1987

Risk assessment, risk perception and decision making about courses of action involving genetic risk: an overview of concepts and methods.

Developments in medical diagnostics and shifts in the ethics of human reproduction increasingly present prospective parents with deliberate choice problems involving possible child deficiencies. An adequate handling of such problems may be supported by explicit methodologies for judging risks and making decisions under uncertainty. The paper gives an overview of concepts, models and methods concerning risk analysis, risk perception and "good" decision making. Several different (stimulus) definitions of risk are presented, and it is shown that "perceived risk" (a response-defined concept) may be operationally measured at different levels of an organism's activity. Disputes on the meaning of probability statements are related to differences in the available information basis which may result from a combination of frequentistic/nonfrequentistic data about, and external/internal determination of possible consequences. After a listing of various notions of "acceptable risk", three different approaches towards making good decisions are discussed. The paper concludes with a summary and some suggestions for the improvement of genetic counseling procedures.

Decision Making↗
PubMedDate not supplied

Role of exposure databases in risk assessment.

Risk assessments have assumed an increasingly important role in the management of risks in this country. The determination of which pollutants or public health issues are to be regulated, the degree and extent of regulation, and the priority assigned to particular problems are all areas of risk assessment that influence the country's $100 billion annual investment in environmental protection. Recent trends in public policy have brought the practice of risk assessment under greater scrutiny. As policy makers increasingly insist that specific numerical risk levels (so-called bright lines) be incorporated into regulatory decisions, the stakes for good risk assessment practice, already high, are raised even further. Enhancing the scientific basis of risk assessments was a major goal of the Workshop on Exposure Databases. In this article, we present the Risk Assessment Work Group's evaluation of the use of exposurerelated databases in risk assessment and the group's recommendations for improvement. The work group's discussion focused on the availability, suitability, and quality of data that underly exposure assessments, a critical component of risk assessment. The work group established a framework for evaluation, based on exposure scenarios typically used in regulatory decisions. The scenarios included examples from Superfund, the Clean Air Act, the Toxic Substances Control Act, and other regulatory programs. These scenarios were used to illustrate current use of exposure data, to highlight gaps in existing data sources, and to discuss how improved exposure information can improve risk assessments. The work group concluded that many of the databases available are designed for purposes that do not meet exposure and risk assessment needs. Substantial gaps exist in measurements of actual human exposure and in the data necessary to model exposures, to characterize distributions of exposure, to identify high-risk groups, and to identify possible environmental inequities in exposure. The work group, on the basis of its findings, made both short-term and longer-term recommendations for improving the collection of exposure data in the future.

Animals↗
PubMed1996

Biokinetics and biokinetic models in risk assessment.

Risk assessment of xenobiotics using animal data involves extrapolation from high doses to low ones, and from animal species to humans. In some cases it also involves extrapolation from one route of exposure to another. To assess the risk of exposure to xenobiotics, information on both biokinetics and biodynamics are needed. The contribution of biokinetics to risk assessment is the subject of this review. The review includes the general aspects of biokinetics of chemicals, the models available to describe the biokinetic behaviour of a chemical and a discussion of the class of biokinetic models that is considered most suited for application to risk assessment: the physiologically-based biokinetic (PBBK) models. The power of PBBK models is illustrated with a few examples.

Administration, Cutaneous↗
PubMed2002

Evaluating public commentary and scientific evidence submitted in the development of a risk assessment.

Risk assessments form the methodological basis for many public policies. A key component of the risk assessment process is the public commentary period. We conducted a case study of the California environmental tobacco smoke risk assessment to describe the contribution of the commentary to the risk assessment process. We used content analysis to examine the sources, quantity, and quality of public commentary, as well as the agency's response to the commentary. We examined the type and quality of publications cited in the commentary. Most of the comments were from critics of the risk assessment (36/44, 80%), especially tobacco industry affiliates (30/36, 83%). Critics were more likely to evoke the science evaluation criteria of study quality, reliability, and validity than were supporters. More than half the critics argued that appropriate procedures were not followed (13/23, 57%). Of the 29 commentaries on the respiratory, carcinogenic, and cardiovascular chapters, four resulted in changes to the risk assessment, such as the addition of new references or reanalysis of data. Journal articles were the most frequently cited type of reference, cited by critics (1,022/1,526 of references, 67%) and supporters (39/60, 65%). However, journal articles submitted by critics had lower impact factors than those cited by supporters (2.6 vs. 3.6, p=0.03). Participation in the public input process was not balanced among all interested parties, although this may reflect different opportunities for stakeholders to participate in stages of the process. Critics and supporters of the risk assessment used different criteria to evaluate the scientific evidence, suggesting that they were socially constructing the evidence to support their positions.

California↗
PubMed1997

Chloroform mode of action: implications for cancer risk assessment.

Risk assessment methodology, particularly pertaining to potential human carcinogenic risks from exposures to environmental chemicals, is undergoing intense scrutiny from scientists, regulators, and legislators. The current practice of estimating human cancer risk is based almost exclusively on extrapolating the results of chronic, high-dose studies in rodents to estimate potential risk in humans. However, many scientists are questioning whether the logic used in this current risk assessment methodology is the best way to safeguard public health. A major tool of human cancer risk assessment is the linearized multistage (LMS) model. The LMS model has been identified as an aspect of risk assessment that could be improved. One way to facilitate this improvement is by developing a way to incorporate a carefully derived, more biologically relevant mechanism of action data on carcinogenesis. Recent data on chloroform indicate that the dose-response relationship for chloroform-induced tumors in rats and mice is nonlinear, based upon events secondary to cell necrosis and subsequent regeneration as the likely mode of action for the carcinogenic effects of chloroform. In light of these data, there is a sound scientific basis for removing some of the uncertainty that accompanies current cancer risk assessments of chloroform. The following points summarize the critical data: (1) a substantial body of data demonstrates a lack of direct in vivo or in vitro genotoxicity of chloroform; (2) chloroform induces liver and kidney tumors in long-term rodent cancer bioassays only at doses that induce frank toxicity at these target sites; (3) the chloroform doses required to produce tumors in susceptible species exceed the MTD, often by a considerable margin; (4) cytotoxicity and compensatory cell proliferation are associated with the chloroform doses required to induce liver or kidney tumors in susceptible rodent species; (5) there are no instances of chloroform-induced tumors that are not preceded by this pattern of dose-dependent toxic responses; (6) it is biologically plausible that cytolethality leads to chronically stimulated cell proliferation and related events such as inflammation and growth stimulation which act to initiate and promote the carcinogenic process; and (7) the consistently linked cellular events of cytolethality and subsequent cell proliferation, for which doses of no adverse effect have been clearly shown to exist, are one of the biological prerequisites for chloroform-induced tumors in animals. Based on these data, it is inappropriate to extrapolate cancer risk from high doses that produce necrosis and regenerative cell proliferation to low doses that do not with a model that presumes genotoxicity and a linear dose-response relationship. The weight of the scientific evidence concerning chloroform-induced tumors in rodents is consistent with and supports a cancer risk assessment methodology based on mode of action as the basis for establishing regulatory standards for this compound.

Administration, Inhalation↗
PubMedDate not supplied

Risk assessment.

Risk assessment, when applied to living systems, is the process of determining the types and likelihoods of adverse effects that may result from exposure to chemical, biological, or physical hazards. Risk assessment is used as a tool to help set regulations and guidelines to prevent or minimize adverse health effects of long-term exposures to low levels of toxicants. It is also applied to evaluating the safety of pharmaceuticals, to protecting workers exposed intermittently to hazardous materials in the workplace, and to evaluating the potential future consequences of past or current exposures. Most toxicological information used in human health risk assessment comes from in vivo experiments in animals and focuses on the pathological response occurring as a result of exposure to the toxicant. Dose and response data must then be extrapolated between individuals and species and from high to low doses, all of which increase the degree of uncertainty in risk estimates. This presentation provides a general overview of risk assessment, exploring its strengths, weaknesses, and ongoing evolution. The distinction between real and perceived risks is also discussed and is shown to be driven by the extent to which mechanistic information is available and how it is integrated into the risk assessment process. Finally, the presentation explores ways in which pathologists and risk assessors can work more closely to enhance risk assessment's ability to be a defensible tool for evaluating health concerns associated with chronic low-level exposures to toxicants in our environment.

Humans↗
PubMed2003

Modeling microbial growth within food safety risk assessments.

Risk estimates for food-borne infection will usually depend heavily on numbers of microorganisms present on the food at the time of consumption. As these data are seldom available directly, attention has turned to predictive microbiology as a means of inferring exposure at consumption. Codex guidelines recommend that microbiological risk assessment should explicitly consider the dynamics of microbiological growth, survival, and death in foods. This article describes predictive models and resources for modeling microbial growth in foods, and their utility and limitations in food safety risk assessment. We also aim to identify tools, data, and knowledge sources, and to provide an understanding of the microbial ecology of foods so that users can recognize model limits, avoid modeling unrealistic scenarios, and thus be able to appreciate the levels of confidence they can have in the outputs of predictive microbiology models. The microbial ecology of foods is complex. Developing reliable risk assessments involving microbial growth in foods will require the skills of both microbial ecologists and mathematical modelers. Simplifying assumptions will need to be made, but because of the potential for apparently small errors in growth rate to translate into very large errors in the estimate of risk, the validity of those assumptions should be carefully assessed. Quantitative estimates of absolute microbial risk within narrow confidence intervals do not yet appear to be possible. Nevertheless, the expression of microbial ecology knowledge in "predictive microbiology" models does allow decision support using the tools of risk assessment.

Bacteria↗
PubMed2003

Underlying issues including approaches and information needs in risk assessment.

Risk assessment requires a delicate consideration of the factors modifying exposure and effects. In this contribution a review is given of the qualitative and quantitative information needs that are essential for a proper risk assessment. The focus is on the details of metal exposure and exposure assessment, following the themes of environmental, physicochemical, and biological components that define exposure. Apart from a description of the principle processes and pathways, exposure assessment is placed in the context of risk assessment and its use in policy and regulatory decision making.

Animals↗
PubMed1996

A conceptual framework to assess the risks of human disease following exposure to pathogens. ILSI Risk Science Institute Pathogen Risk Assessment Working Group.

Currently, risk assessments of the potential human health effects associated with exposure to pathogens are utilizing the conceptual framework that was developed to assess risks associated with chemical exposures. However, the applicability of the chemical framework is problematic due to many issues that are unique to assessing risks associated with pathogens. These include, but are not limited to, an assessment of pathogen/host interactions, consideration of secondary spread, consideration of short- and long-term immunity, and an assessment of conditions that allow the microorganism to propagate. To address this concern, a working group was convened to develop a conceptual framework to assess the risks of human disease associated with exposure to pathogenic microorganisms. The framework that was developed consists of three phases: problem formulation, analysis (which includes characterization of exposure and human health effects), and risk characterization. The framework emphasizes the dynamic and iterative nature of the risk assessment process, and allows wide latitude for planning and conducting risk assessments in diverse situations, each based on the common principles discussed in the framework.

Disease↗
PubMed1988

Perceived risk, real risk: social science and the art of probabilistic risk assessment.

Risk assessment is commonly seen as the domain of physical and biological sciences, with social scientists focusing instead on risk management and communication. This division is unnecessary, and it may lead to errors in risk assessments. Social science input is needed for more accurate calculations of risk consequences and probabilities and for identifying potential biases created by certain risk assessment procedures, as well as in analyzing and explaining public responses to risk. Findings, moreover, suggest that the dichotomy between "real" and "perceived" risk is less "real" than is often assumed, particularly in cases involving controversial technologies.

Accidents↗
PubMed1993

Mechanistic modelling and risk assessment.

Risk Assessment in the United States has been rapidly changing over the last few years. The historical methods and endpoints by which risk estimates were derived are gradually being replaced by newer methods and a broader spectrum of endpoints. For carcinogenic risk assessment, there is movement from the routinely used "linearized multistage model" for low dose risk estimation to methodology which is more deeply rooted in carcinogenic mechanisms and which allows the incorporation of additional data into the estimation of risks in a direct, quantitative fashion. There is also a determined effort under way to develop methods for assessing risks from exposure based on other endpoints such as effects on the immune system and the reproductive system. This paper briefly discusses some of the statistical and mathematical issues which will play important roles in determining the utility and precision of these new methods for estimating risks from environmental exposures.

Animals↗