Any iodine-131 (I-131) released from the X-10 site on the Oak Ridge Reservation, TN, during the 1940s through 2004 has decayed completely or is currently not present in the environment at levels of health concern, says the public health assessment released by the Agency for Toxic Substances and Disease Registry (ATSDR).

The agency will host a meeting at the Doubletree Hotel, 215 South Illinois Ave. in Oak Ridge on Sept. 11 from 6:00 to 8:00 p.m. to discuss these findings and its recommendations.

ATSDR conducted the public health assessment to evaluate whether past, current and potential future releases of I-131 from the Oak Ridge Reservation could harm people living in communities near the reservation. The radioactive lanthanum (RaLa) process at the X-10 site released I-131 into the air from 1944 to 1956. People who lived near the ORR during this time could have come in contact with I-131, primarily from drinking local goat’s and cow’s milk.

Because of limitations with available data, ATSDR cannot reach a definitive conclusion about the potential for health effects from past I-131 exposures for those residents who were under the age of 18 at RaLa was processed. However, after reviewing historical air monitoring data and current literature, ATSDR did conclude the following about past I-131 releases:

• Recently discovered historical air monitoring data from the early and mid-1950s and deer thyroid data from 1979 to 1989 suggest that I-131 released into the air from RaLa processing did not extend beyond the X-10 site boundary at levels that would cause a public health hazard.
  
  
• Individuals who were living near the Oak Ridge Reservation and who were at least 21 years of age during RaLa processing were not exposed to I-131 at levels that would have caused thyroid diseases or thyroid cancer.
  
  
• Individuals who were under the age of 18, who lived near the Oak Ridge Reservation during the years of RaLa processing, and who may have received a thyroid radiation dose in excess of 10 rads are the critical-sensitive population with the potential for developing thyroid diseases, including thyroid cancer. However, because sufficient information was not available about the actual areas impacted by RaLa releases, ATSDR cannot identify which communities surrounding the X-10 site may have been impacted in the past by thyroid doses in excess of 10 rads.
  

ATSDR recommends collecting on- and off-site soil samples downwind and upwind of Oak Ridge National Laboratory and analyzing these soil samples for I-129.  Although I-131 from the RaLa process is no longer present in the environment, the current radioactivity of I-129 in the soil can be used to evaluate past I-131 concentrations. Data collected from this I-129 analysis can be used to address the uncertainties associated with the estimated thyroid doses in the 1999 Tennessee Department of Health report Oak Ridge Dose Reconstruction Task 1 Report ¯Iodine 131 Releases from the Radioactive Lanthanum Process at the X-10 Site in Oak Ridge, Tennessee (1944-1956) and to better define the off-site populations impacted by I-131 releases.

The public health assessment is available to the public for review and comment, however ATSDR will not be able to address comments or make this report final unless additional U.S. Department of Energy funds are received. Community members are encouraged to submit comments during the public comment period, even though we do not know whether ATSDR will be able to respond. Public comments are an important part of the public record.

The public health assessment is available at the following locations:

The ATSDR Oak Ridge Field Office is now closed. Members of the community with questions about this public health assessment may contact Senior Health Physicist Paul Charp, Ph.D., Environmental Health Scientist Jack Hanley or Health Communication Specialist Marilyn Palmer Horton, toll free, at 1-800-CDC-INFO. Or, for more information about ATSDR activities at the Oak Ridge Reservation, visit www.atsdr.cdc.gov/HAC/oakridge.

ATSDR, a federal public health agency of the U.S. Department of Health and Human Services, evaluates the human health effects of exposure to hazardous substances.