Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock ( Lock A locked padlock ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

  • Environmental Topics
  • Laws & Regulations
  • Report a Violation
  • About EPA
Risk Assessment
Contact Us

THYROID FOLLICULAR CELL CARCINOGENESIS: MECHANISTIC AND SCIENCE POLICY CONSIDERATIONS (SAB REVIEW DRAFT)

On this page:

  • Overview
  • History

Alert
Alert Notice - This site contains archived material(s)

Archive disclaimer
Archived files are provided for reference purposes only. The file was current when produced, but is no longer maintained and may now be outdated. Persons with disabilities having difficulty accessing archived files may contact the Risk Webmaster for assistance. Please use the contact us form if you need additional support.

Abstract

A Technical Panel of EPA's Risk Assessment Forum investigated the potential mechanisms of action of agents that cause thyroid follicular tumors in animals and potentially in humans in an effort to develop a scientifically plausible approach for assessing risk due to exposure to these agents. Based on its review of relevant scientific information, the Technical Panel concluded that:

(1) thyroid follicular cell tumors may arise from long-term disturbances in thyroid-pituitary hormonal feedback under conditions of reduced circulating thyroid hormone and elevated thyroid stimulating hormone (TSH);
(2) the steps leading to these tumors are expected to show thresholds, such that the risks of tumor development are minimal when thyroid-pituitary homeostasis exists; and
(3) models that assume thresholds may be used to assess the risks of certain thyroid follicular cell tumors where there is evidence of thyroid-pituitary imbalance.

The policy set out in this report provides guidance on determining whether it is reasonable to presume that the observed thyroid follicular tumors are the result of thyroid-pituitary imbalance, and on selecting appropriate procedures to use in estimating the risks related to these tumors.

History/Chronology

Additional Information

Note: a complete electronic version of this document that preserves its original appearance (such as in a pdf file format) is not currently available.
  • Risk Assessment Home
  • About Risk Assessment
  • Risk Recent Additions
  • Human Health Risk Assessment
  • Ecological Risk Assessment
  • Risk Advanced Search
    • Risk Publications
  • Risk Assessment Guidance
  • Risk Tools and Databases
  • Superfund Risk Assessment
  • Where you live
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on August 17, 2010
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshots
  • Grants
  • No FEAR Act Data
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data
  • Inspector General
  • Jobs
  • Newsroom
  • Open Government
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions

Follow.