Bookmark and Share

Health Risk Science -
U.S. National Research Council Risk Assessment Framework

The National Research Council was established by the United States National Academy of Sciences in 1916 to advise the federal government within the broad community of science and technology.   Upon the initiative of the United States Congress, the National Research Council conducted a study to strengthen the reliability and objectivity of the scientific assessment that forms the basis for federal regulatory policies pertaining to carcinogens and other public health hazards.  This study was conducted under contract with the U.S. Food and Drug Administration within the Department of Health and Human Services.

The NRC (1983a) model consists of two stages: risk assessment and risk management (see figure) {National Research Council 1983 234 /id}.   Risk assessment refers to the use of a factual base to define the health effects of the exposure of individuals or populations to hazardous materials or situations. Elements of risk assessment are numerous and include a description of the potential adverse health effects determined in epidemiological, clinical, toxicological, and environmental studies. Results obtained from research need to be extrapolated before the type and extent of health effects in exposed humans to a specific substance can be predicted. Risk assessment also includes judgments on exposed individuals to determine the number and characteristics and those exposed at a range of intensities and durations.  Finally, risk assessment can facilitate summary judgments on whether any public-health problems are factual and important while taking into account uncertainties.  Risk management is the process of evaluating regulatory options and selecting from among them.

Risk assessment is subdivided into four components: hazard identification, dose response assessment, exposure assessment, and risk characterization. The process of risk assessment doesn’t always contain all four components because it is possible that no adverse health effect is found, and no further analyses are required. At the risk management stage, alternative regulatory options are developed and evaluated. Selection of a particular regulatory option involves consideration of the public health, economic, social, and political consequences of implementation. 

The NRC model was subsequently adopted by the United States Environmental Protection Agency (1984) {United States Environmental Protection Agency 1984 245 /id} with no significant structural or definitional changes.   The United States Department of Health and Human Services (DHHS) {United States Department of Health and Human Services 1985 244 /id} has expanded the NRC model to include consideration of nonregulatory options for risk management.  These include advisory options as well as risk reduction through technological means.   The DHHS also recommends expansion of research so as to reduce the uncertainties associated with scientific knowledge. 

U.S. National Research Council Framework for Risk Assessment (1983)



National Research Council. 1983. Risk Assessment in the Federal Government: Managing the Process. National Academy Press, Washington, D.C.

Home             Links              Sitemap               Contact Us
© McLaughlin Centre for Population Health Risk Assessment