Environmental Compliance

Risk Assessments

Risk assessments are characterizations of the potential adverse effects to human health and the environment from environmental hazards. They may be independent documents used for planning purposes, or may be subordinate parts of more complex analyses such as environmental impact statements. The Animal and Plant Health Inspection Service (APHIS) routinely prepares several types of risk assessments for its programs, including human health risk assessments, nontarget species risk assessments, and ecological risk assessments.

Other kinds of risk assessments also may be used in Agency planning or decisionmaking. These include pest risk assessments and economic impact assessments. These documents provide basic information about pest characteristics, effectiveness of control methods, and costs of various actions or alternatives or lack thereof. The Council on Environmental Quality's National Environmental Policy Act implementing regulations (40 CFR  1502.14(a)) require the Agency to "rigorously explore and objectively evaluate all reasonable alternatives," and these
documents facilitate and enhance that process.

Traditionally, risk assessment involves hazard identification, exposure assessment, and a method of exposure-response assessment to determine the risk. The calculations required are generally quantitative, but qualitative determinations based on available evidence are sometimes required when quantitative data are scarce. The calculation of risk has generally been made for populations, on a species-by-species basis. However, the survival of an individual species may depend upon the protection of habitats or susceptible individuals within the population. This has resulted in an emphasis on protection of ecosystems and landscapes rather than individuals. Differing approaches have been used to determine risk in special situations, such as for endangered and threatened species (where regulations have placed an emphasis on individuals of the species) or for hypersensitive individuals within a population (where minimal exposures can result in high risk).