"Published under the joint sponsorship of the United Nations Environment Programme, the International Labour Organisation and the World Health Organization, and produced within the framework of the Inter-Organization Programme for the Sound Management of Chemicals."

Risk assessment has become a dominant public policy tool for making choices, based on limited resources, to protect public health and the environment. It has been instrumental to the mission of the U.S. Environmental Protection Agency (EPA) as well as other federal agencies in evaluating public health concerns, informing regulatory and technological decisions, prioritizing research needs and funding, and in developing approaches for cost-benefit analysis. However, risk assessment is at a crossroads. Despite advances in the field, risk assessment faces a number of significant challenges including lengthy delays in making complex decisions; lack of data leading to significant uncertainty in risk assessments; and many chemicals in the marketplace that have not been evaluated and emerging agents requiring assessment. Science and Decisions makes practical scientific and technical recommendations to address these challenges. This book is a complement to the widely used 1983 National Academies book, Risk Assessment in the Federal Government (also known as the Red Book). The earlier book established a framework for the concepts and conduct of risk assessment that has been adopted by numerous expert committees, regulatory agencies, and public health institutions. The new book embeds these concepts within a broader framework for risk-based decision-making. Together, these are essential references for those working in the regulatory and public health fields.

The public depends on competent risk assessment from the federal government and the scientific community to grapple with the threat of pollution. When risk reports turn out to be overblownâ€"or when risks are overlookedâ€"public skepticism abounds. This comprehensive and readable book explores how the U.S. Environmental Protection Agency (EPA) can improve its risk assessment practices, with a focus on implementation of the 1990 Clean Air Act Amendments. With a wealth of detailed information, pertinent examples, and revealing analysis, the volume explores the "default option" and other basic concepts. It offers two views of EPA operations: The first examines how EPA currently assesses exposure to hazardous air pollutants, evaluates the toxicity of a substance, and characterizes the risk to the public. The second, more holistic, view explores how EPA can improve in several critical areas of risk assessment by focusing on cross-cutting themes and incorporating more scientific judgment. This comprehensive volume will be important to the EPA and other agencies, risk managers, environmental advocates, scientists, faculty, students, and concerned individuals.

Introduction to Chemical Exposure and Risk Assessment focuses on the principles involved in assessing the risks from chemical exposure. These principles include the perception of risk, an understanding of how numbers are handled, and how chemicals affect health. The book briefly describes the major sinks, such as water and air, where chemicals are introduced. This is followed by a discussion on how concentrations are estimated and risk assessments are made. A discussion of risk benefit analysis and a presentation of several case studies using the principles for assessing risks are also included.

The objective of this manual is to provide guidance to risk assessors on the use of quantitative toxicokinetic and toxicodynamic data to address interspecies and interindividual differences in dose and concentration-response assessment. Section 1 focuses on the relevance of this guidance in the context of the broader risk assessment paradigm and other initiatives of the International Program on Chemical Safety (IPCS) project on the Harmonization of Approaches to the Assessment of Risk from Exposure to Chemicals. Technical background material is presented in section 2, followed by generic guidance for the development of chemical-specific adjustment factors in section 3 and accompanying summary figures. Illustrative case-studies are included in an Appendix, and a glossary of terms is also provided.--Publisher's description.

A state-of-the-art review of methods and procedures for assessing the risks to human health posed by environmental chemicals. Addressed to regulatory authorities, risk managers and other decision-makers, the book aims to demystify the principles of risk assessment and thus encourage wider use of this powerful tool for protecting populations. Since the detection of chemical hazards may have socioeconomic and political consequences, the book gives particular attention to methods for the accurate identification of risks and determination of their severity. The book has four chapters covering each logical step in the process of risk assessment. The first, on hazard identification, explains how data on a chemical's toxicity and mode of action can be used to determine whether the chemical will cause adverse effects on health. The strengths and limitations of different types of data are discussed together with criteria commonly used to establish causality. Methods for assessing dose-response relationships are reviewed in chapter two, which explains how to characterize the relationship between the dose administered or received and the incidence of an adverse effect. Exposure assessment is covered in the next chapter, which describes methods for determining the nature and extent of contact with chemical substances and discusses the characteristics of exposure in the general environment, in the workplace, and from consumer products. The final chapter explains the procedure of risk characterization as a decision-making tool that brings together estimates of exposure levels and risks and summarizes sources of uncertainty in the scientific data. Practical options for risk management are presented as a range of regulatory, non-regulatory, economic, and technological measures.

and for those interested in toxic effects of chemicals on humans, Human Variability in Response to Chemical Exposures: Measures, Modeling, and Risk Assessment recognizes and addresses the increasing awareness that individual biological differences be reflected when assessing human health risks associated with exposure to chemicals. Eight original manuscripts, commissioned by the ILSI Risk Science Institute, address the evidence for variability in human response to chemicals associated with reproductive and developmental effects, effects on the nervous system and lungs, and cancer. Their reports convey both the current state of scientific understanding of response variability and the genetic basis for such observations. This book recognizes that understanding of variability in response is critical in accounting for interindividual variability in susceptibility and, hence, risk, if the regulatory community and others are expected to characterize human health risks associated with exposure to chemicals. Models for incorporating measures of response variability in the risk assessment process are critically reviewed and illustrated with published data. This authoritative work indicates that, in the case of certain chemicals and in the context of certain specific toxic effects, we have considerable ability to predictively and quantitatively characterize human variability, but, in the majority of cases, our ability to do so is limited. If we improve both quantity and quality of information available on response variability and increase our understanding of target tissue dosimetry, we should be better able to account for variability in human susceptibility to the toxic effects of chemicals.