The History of Risk at EPA
- 1970s: EPA was involved with risk assessment practices since EPA’s early days, although risk assessment per se was not a formally recognized process then. EPA completed its first risk assessment document in December 1975: Quantitative Risk Assessment for Community Exposure to Vinyl Chloride (Kuzmack and McGaughy, 1975*). The next significant document appeared in 1976: Interim Procedures and Guidelines for Health Risk and Economic Impact Assessments of Suspected Carcinogens (Train, 1976*). The preamble of this document, signed by the Administrator, signaled the Agency’s intent that "rigorous assessments of health risk and economic impact will be undertaken as part of the regulatory process." A general framework described a process to be followed in analyzing cancer risks of pesticides, and the document recommended that the health data be analyzed independently of the economic impact analysis.
- 1980s: EPA announced the availability of water quality criteria documents for 64 contaminants (USEPA, 1980*). This was the first application of quantitative procedures developed by EPA to a large number of carcinogens, and the first EPA document describing quantitative procedures used in risk assessment.
Then in 1983, the National Academy of Science (NAS) published Risk Assessment in the Federal Government: Managing the Process (NRC, 1983*; commonly referred to as the “Red Book”). EPA has integrated the principles of risk assessment from this groundbreaking report into its practices to this day. The following year, EPA published Risk Assessment and Management: Framework for Decision Making (USEPA, 1984*), which emphasizes making the risk assessment process transparent, describing the assessment’s strengths and weaknesses more fully, and providing plausible alternatives within the assessment. Also in the 80's, EPA releases the Integrated Risk Information System (IRIS), a database of human health effects that may result from exposure to various substances found in the environment.
- 1990s: Shortly after the publication of the Red Book, EPA began issuing a series of guidelines for conducting risk assessments (e.g., in 1986 for cancer, mutagenicity, chemical mixtures, developmental toxicology, and in 1992 for estimating exposures). Although EPA efforts focused initially on human health risk assessment, the basic model was adapted to ecological risk assessment in the 1990s to deal with risks to plants, animals and whole ecosystems.
Over time, the NAS expanded on its risk assessment principles in a series of subsequent reports, including Pesticides in the Diets of Infants and Children (NRC, 1993*), Science and Judgment in Risk Assessment (NRC, 1994*; also known as the “Blue Book”), and Understanding Risk: Informing Decisions in a Democratic Society (NRC, 1996*). For example, the NAS places equal emphasis on fully characterizing the scope, uncertainties, limitations, and strengths of the assessment and on the social dimensions of interacting with decision makers and other users of the assessment in an iterative, analytic-deliberative process. The purpose of this process is to ensure that the assessments meet the intended objectives and are understandable. EPA risk assessment practices have evolved over time along with this progression of thought, and in many cases helped drive the evolution of thinking on risk assessment.
In 1995, EPA updated and issued the current Agency-wide Risk Characterization Policy (USEPA, 1995a*). The Policy calls for all risk assessments performed at EPA to include a risk characterization to ensure that the risk assessment process is transparent; it also emphasizes that risk assessments be clear, reasonable, and consistent with other risk assessments of similar scope prepared by programs across the Agency. Effective risk characterization is achieved through transparency in the risk assessment process and clarity, consistency, and reasonableness of the risk assessment product — TCCR. EPA’s Risk Characterization Handbook (USEPA, 2000a*) was developed to implement the Risk Characterization Policy.
The Congressional/Presidential Commission on Risk Assessment and Risk Management (CRARM) was created by the Clean Air Act Amendments of 1990 and formed in 1994. Its mandate was to make a full investigation of the policy implications and appropriate uses of risk assessment and risk management in regulatory programs, under various federal laws, designed to prevent cancer and other chronic health effects that may result from exposure to hazardous substances. More specifically, its mandate was to provide guidance on how to deal with residual emissions from Section 112 hazardous air pollutants (HAPs) after technology-based controls have been placed on stationary sources of air pollutants. In 1997, the Commission published its report in two volumes (CRARM, 1997a*; CRARM, 1997b*). These discussed the importance of better understanding and quantification of risks, as well as the importance of evaluating strategies to reduce human and ecological risks.
- 2000s: EPA’s risk assessment principles and practices build on our own risk assessment guidances and policies — such as the Risk Characterization Policy; Guidance for Cumulative Assessment, Part 1: Planning and Scoping (USEPA, 1997a*); the Risk Assessment Guidance for Superfund, or RAGS (USEPA, 1989a*, and subsequent updates); EPA’s Information Quality Guidelines (USEPA, 2002a*); and A Summary of General Assessment Factors for Evaluating the Quality of Scientific and Technical Information (USEPA, 2003a*) — as well as the NAS, the CRARM, and others’ concepts. It is understood that risk assessment provides important information about the nature, magnitude, and likelihood of possible environmental risks to inform decisions — principles that evolved out of these many efforts.