Risk Assessment

Risk is the chance of an injury, illness or death caused by exposure to a hazard. The EPA defines risk as "The probability of injury, disease, or death under specific circumstances." Environmental risk assessment is a tool that helps people make informed decisions in determining the use of a potentially hazardous substance, or about actions to take when environmental contamination has already occurred. Environmental contaminants can cause injury to humans, animals, the ecosystem, the economy and aesthetics. Risk assessment provides an evaluation of the likelihood and severity of these injuries. This series of pages will describe a basic framework for human and ecological health-based risk assessment, describe standards of risk assessment, risk management and ends with a discussion about risk communication. The processes of risk assessment for human health and ecology are similar. Factsheets on each process are available. A diagram will help show how the processes flow.

For the other risk-related pages, please see:

  • Steps to Assessment. This page describes detailed descriptions of the steps in risk assessment, with emphasis on human health risk assessment.
  • Risk Assessment Standards This page provides a discussion on standards for risk assessment based on the American Society for Testing and Materials.
  • Ecological Risk Assessment This page focuses on the unique aspects of ecological risk assessment.
  • Risk Management This page provides information about plans for managing and/or preventing risk.
  • Risk Communication This page provides information about communicating with communities facing contaminated sites.
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