More than 21,000 contaminated sites have been identified on Department of Defense (DoD) installations. The scope of this environmental problem is obvious whether one considers the nature and extent of contamination or the amount of resources required to evaluate and/or clean up such a large number of sites. Under most circumstances, decisions regarding the need for and the scope of any cleanup action will be driven by environmental risk assessment. As required by Federal regulation, such assessments must address the potential risk to human health and the environment posed by the contaminants present at any particular site. Over the last 20 years, methods for performing human health risk assessments have developed, matured, and been incorporated into well established Federal guidance used within various Federal programs and agencies, Compensation and Liability Act or Superfund. Greater public concern recent years has been focused on more general environmental problems resulting from the presence of contaminants in the environment. However, the issues involved in making a determination about the broader ecological consequences of contaminant exposure are more complex than those related to human health risk. This fact is most simply illustrated by considering that human heath risk assessments need only focus on the risk to one receptor, humans; whereas, an ecological risk assessment must potentially consider the risk to hundreds of interacting species located at any particular site. This disparity in the complexity involved in human and ecological assessments of risk is further emphasized by the fact that for ecological risk assessments, the number and kinds of receptors vary considerably from site to site.

A Practical Guide to Understanding, Managing and Reviewing Environmental Risk Assessment Reports provides team leaders and team members with a strategy for developing the elements of risk assessment into a readable and beneficial report. The authors believe that successful management of the risk assessment team is a key factor is quality repor

The Fate & Effects Advisory Committee (FEAC) identified the need for the development of models capable of providing information relating to the fate and effects of Military Relevant Compounds (MRCs) on both ecological and human resources. Requirements for better modeling capabilities of contaminant concentration over time for risk assessment were stated. In an effort to address the requirement, a work unit was initiated for the development of an Army Risk Assessment Modeling System (ARAMS). This system will incorporate other research efforts conducted in the Fate & Effects Research Program and will enable thorough evaluation of ecological and human risk assessments. The ARAMS will be developed for the purpose of conducting ecological and human risk assessments. Development of this system will incorporate current state-of-the-art modeling technologies and will further utilize concurrent research efforts in the Fate and Effects Research Program. ARAMS is a tool to characterize, integrate, and estimate ecological risk. The system will provide several tiers of complexity such that screening-level and complex model issues can be addressed. The system will include: (a) screening level assessments based on simple exposure-response relationships and limited spatial and temporal scales, (b)an expanded assessment capability based on linkage of more rigorous exposure and ecological assessment techniques, and (c) linkage of ecological risk, comprehensive exposure models, and integrated temporal-spatial exposure,..i.e., probabilistic estimate of exposure for individuals/population in time and space. The objective of this workshop was to ascertain the current state of the art in risk assessment modeling and to facilitate discussion of the components required for an ARAMS is anticipated to take several years to complete.

Preparation for anticipated, unknown, and invariably adverse battlefield conditions requires military training activities involving military smokes and obscurants (S & Os) and related chemical compounds, and can result in the release of other chemical agents and military unique compounds (MUCs) associated with munitions. This study evaluates the potential long-term impacts on selected threatened and endangered species resulting from dispersion and deposition of vapors and particles found in the fog oils, hexachloroethane smoke, colored smokes, white phosphorus, and obscurants such as brass flakes and graphite flakes used during training. Residue from these constituents can deposit directly on plants and prey species favored by higher vertebrates and other species or can be taken up by plants and prey species from the soil. From the literature and installation use reports, the authors develop estimates of toxicity and exposure to calculate installation-specific screening-level risk for selected threatened and endangered species.

The Department of Defense (DoD) lacks the methodology to address risks to natural resources resulting from multiple activities, multiple effects, and cumulative effects of military activities. The objective of this project was to develop a structured, scientifically valid, integrated Ecological Risk Assessment (ERA) framework to provide, at both the installation and command levels, a common context for characterizing different kinds of risks for comparison and prioritization for risk-based sustainable management of DoD training and testing assets. This document provides a risk assessment framework consistent with, but extending beyond, the EPA's ecological risk assessment framework, and specifically addresses DoD-activities and management needs. It is titled Military Ecological Risk Assessment Framework (MERAF) to convey this military focus. The modifications made to the EPA ecological risk assessment framework in developing MERAF enable MERAF to: (1) explicitly address risks from the imposition of multiple and diverse stressors on a site, (2) explicitly address risks resulting from causal chains (e.g., effects on habitat that indirectly impact wildlife), and (3) incorporate the fact that risks to natural resources imply other consequent risks.

The objective of this research is to provide the DoD with a framework based on a systematic, risk-based approach to assess impacts for management of natural resources in an ecosystem context. This risk assessment framework is consistent with, but extends beyond, the EPA's ecological risk assessment framework, and specifically addresses DoD activities and management needs. MERAF is intended to be consistent with existing procedures for environmental assessment and planning with DoD testing and training. The intention is to supplement these procedures rather than creating new procedural requirements. MERAF is suitable for use for training and testing area assessment and management. It does not include human health risks nor does it address specific permitting or compliance requirements, although it may be useful in some of these cases. Use of MERAF fits into the National Environmental Policy Act (NEPA) process by providing a consistent and rigorous way of organizing and conducting the technical analysis for Environmental Impact Statements (EISs) (Sigal 1993; Carpenter 1995; Canter and Sadler 1997). It neither conflicts with, nor replaces, procedural requirements within the NEPA process or document management processes already in place within DoD.

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.