National Academy of Sciences | 150 Year Anniversary

Questions? Call 800-624-6242

| Items in cart [0]

The National Academies Press

PAPERBACK
price:$52.00
add to cart

Rights & Permissions

topleft topright

Health Risks from Dioxin and Related Compounds: Evaluation of the EPA Reassessment (2006)
Board on Environmental Studies and Toxicology (BEST)

Citation Manager

. "7 Review of Risk Characterization." Health Risks from Dioxin and Related Compounds: Evaluation of the EPA Reassessment. Washington, DC: The National Academies Press, 2006.

Please select a format:

BibTeX EndNote RefMan


Page
187
bottomleft bottomright

The following HTML text is provided to enhance online readability. Many aspects of typography translate only awkwardly to HTML. Please use the page image as the authoritative form to ensure accuracy.


Health Risks from Dioxin and Related Compounds: Evaluation of the EPA Reassessment

als with high intakes. The lack of such a focus in the Reassessment results in a diffuse risk characterization that is difficult to follow and that does not provide clear guidance to risk managers.

The Reassessment should describe clearly the following aspects:

  1. The effects seen at the lowest body burdens that are the primary focus for any risk assessment—the “critical effects.”

  2. The modeling strategy used for each noncancer effect, paying particular attention to the critical effects, and the selection of a point of comparison based on the biological significance of the effect; if the ED01 is retained, then the biological significance of the response should be defined and the precision of the estimate given.

  3. The precision and uncertainties associated with the body burden estimates for the critical effects at the point of comparison, including the use of total body burden rather than modeling steady-state concentrations for the relevant tissue.

  4. The committee encourages EPA to calculate RfDs as part of its effort to develop appropriate margins of exposure for different end points and risk scenarios, including the proportions of the general population and of any identified groups that might be at increased risk (See Table A-1 in the Reassessment, Part III Appendix, for the different effects; appropriate exposure information would need to be generated.) Interpretation of the calculated values should take into consideration the uncertainties in the POD values and intake estimates.

  5. Consideration of individuals in susceptible life stages or groups (e.g., children, women of childbearing age, and nursing infants) who might require an estimation of a separate MOE using specific exposure data.

  6. Distributions that provide clear insights about the uncertainty in the risk assessments, along with discussion about the key contributors to the uncertainty.

Page
187