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Applications of Toxicogenomic Technologies to Predictive Toxicology and Risk Assessment (2007) / Chapter Skim
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Appendix C: Overview of Risk Assessment
Pages 270-276

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From page 270...
... An Overview of Current Risk Assessment Practice Government agencies charged with protecting public and worker health are required to review, quantify, and ultimately regulate chemicals, physical agents, and pharmaceuticals in a manner that will protect and enhance the public health and the environment. One of these regulatory responsibilities is to assess the risk to human health from chemical exposures.
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From page 271...
... Step 3: Exposure assessment involves specifying the population that might be exposed to the agent of concern, identifying the routes through which exposure can occur, and estimating the magnitude, duration, and timing of the doses that people might receive as a result of their exposure. Step 4: Risk characterization involves integrating information from the first three steps to develop a qualitative or quantitative estimate of the likelihood that any of the hazards associated with the agent of concern will be realized in exposed people.
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From page 272...
... Toxicogenomic data may also be used to better understand areas of uncertainty, including variability in the human population, extrapolation of data from one species to another, identification of susceptible subpopulations, and provision of quantitative data to improve risk assessments. Quantification of Risk Different analytical techniques are used in cancer and noncancer risk assessments to quantify risk.
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From page 273...
... The EPA cancer guidance (EPA 2005) states that "when available data are insufficient to establish the mode of action for a tumor site and when scientifically plausible based on the available data, linear extrapolation is used as a default approach."8 Further, "A nonlinear approach should be selected when there are sufficient data to ascertain the mode of action and conclude that it is not linear at low doses and the agent does not demonstrate mutagenic or other activity consistent with linearity at low doses." For 5 In some cases, the largest divisor the EPA will use is 3,000 because of the uncertainty when so many uncertainty factors are applied (for example, see the risk assessment for trichloroethylene (EPA 2001)
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From page 274...
... Environ mental Protection Agency by Members of the Risk Assessment Task Force.
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From page 275...
... Washington, DC: The National Academies Press. PCCRARM (Presidential/Congressional Commission on Risk Assessment and Risk Management)
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Key Terms

  • noncancer risk
  • risk assessments
  • hazard identification
  • uncertainty spanning
  • reference dose

  • deleterious effects
  • linear extrapolation
  • reference concentration
  • exposure assessment
  • cancer risk

  • critical effect
  • ing sensitive
  • risk characterization
  • risk estimates
  • animal data

  • lifetime exposure
  • health risk
  • appreciable risk
  • sensitive subgroups
  • toxicogenomic data

  • uncertainty factors
  • protecting public
  • reference value
  • quantify risk
  • agencies charged

  • body burdens
  • otherwise reduce
  • complete databases
  • empirically observable
  • clarify data


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