Recently, environmental scientists have been required to perform a new type of assessment-ecological risk assessment. This is the first book that explains how to perform ecological risk assessments and gives assessors access to the full range of useful data, models, and conceptual approaches they need to perform an accurate assessment. It explains how ecological risk assessment relates to more familiar types of assessments. It also shows how to organize and conduct an ecological risk assessment, including defining the source, selecting endpoints, describing the relevant features of the receiving environment, estimating exposure, estimating effects, characterizing the risks, and interacting with the risk manager. Specific technical topics include finding and selecting toxicity data; statistical and mathematical models of effects on organisms, populations, and ecosystems; estimation of chemical fate parameters; modeling of chemical transport and fate; estimation of chemical uptake by organisms; and estimation, propagation, and presentation of uncertainty. Ecological Risk Assessment also covers conventional risk assessments, risk assessments for existing contamination, large scale problems, exotic organisms, and risk assessments based on environmental monitoring. Environmental assessors at regulatory agencies, consulting firms, industry, and government labs need this book for its approaches and methods for ecological risk assessment. Professors in ecology and other environmental sciences will find the book's practical preparation useful for classroom instruction. Environmental toxicologists and chemists will appreciate the discussion of the utility for risk assessment of particular toxicity tests and chemical determinations.

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 U.S. Environmental Protection Agency was created to protect public health and the environment, and it has traditionally emphasized its regulatory mission over its scientific mission. Yet for environmental policy to be credible with the public and policymakers, EPA's actions must have a sound basis in science. In Science at EPA, Mark Powell offers detailed case studies that map the origins, flow, and impact of scientific information in eight EPA decisions involving the agency's major statutory programs. Drawing on extensive research and interviews, he provides the most comprehensive examination available on the acquisition and use of science in environmental regulation. Powell describes the key obstacles to the practical, efficient, and effective acquisition and use of knowledge in what is a crucial, but complex endeavor. His book is an essential contribution for practitioners, scholars and students, and citizens who are determined to protect our environment rationally and effectively.