Exposure to I-131 from Hanford Nuclear Reservation: Hanford Community Health Project (HCHP)

Did you grow up near the Hanford Nuclear Reservation? If so, there is a health resource, developed by the U.S. Department of Health and Human Services, for you to learn more about potential exposure to radiation (radioactive iodine 131) released from Hanford.

Between 1944 and 1972 radioactive iodine (I-131) was released from the Hanford Nuclear Reservation. The majority of these releases occurred between 1944 and 1951. The releases were related to the production of plutonium for use in nuclear weapons.

It’s estimated that children who were up to five years old and lived in Adams, Benton or Franklin counties in Washington state at the time of the releases, received the highest doses of I-131. Today, these are adults between the ages of 54 and 65. Much of this exposure came through consumption of contaminated milk produced by cows (and goats) grazing on contaminated pastures downwind of Hanford.

Public health researchers have conducted extensive epidemiological research around the releases of I-131 at Hanford and the potential link to thyroid disease. The Hanford Thyroid Disease Study, published in June 2002, did not show any association between Hanford’s I-131 releases and the occurrence of thyroid disease.

Other epidemiological studies, including investigations at Chernobyl and the Marshall Islands, have shown that exposure to radioactive iodine is associated with an increased risk of developing thyroid cancer and other thyroid related diseases.

Despite the findings of the Hanford Thyroid Disease Study, downwinders remain concerned about the releases, and there is a demonstrated need in the community for more educational resources. To address this need the Hanford Community Health Project has developed new resources for people concerned about exposure.

What Interested Individuals Can Do

Visit www.hanfordhealth.info. This web site has educational resources about exposure to I-131 including:

  • A self-assessment tool. A guide to help you learn if you were exposed
  • HCHP mailing list sign-up form
  • Educational materials about the releases from Hanford so you can work with your physician to make more informed health care choices
  • HCHP information line toll-free at 1-800-207-3996

About the Hanford Community Health Project

The Hanford Community Health Project (HCHP) is an outreach and education initiative sponsored by ATSDR (Agency for Toxic Substances and Disease Registry) of the U.S. Department of Health and Human Services. The project provides educational resources to individuals, and their health care providers, who were exposed as young children to radioactive iodine (I-131) released from the Hanford Nuclear Reservation in south central Washington state. The focus is on releases of I-131 that took place between 1944 and 1951.The project's goal is to assist concerned individuals and their health care providers in making informed health care choices concerning these exposures. For more information visit www.hanfordhealth.info.


The mission of the Agency for Toxic Substances and Disease Registry (ATSDR), as an agency of the U.S. Department of Health and Human Services, is to serve the public by using the best science, taking responsive public health actions, and providing trusted health information to prevent harmful exposures and disease related to toxic substances. For more information visit www.atsdr.cdc.gov.

Last updated: October 23, 2006