Overview

Toxic Releases: A Little History

In the 1940s, the Manhattan Project built several nuclear sites around the country, including a main facility 25 miles east of Knoxville, Tennessee. The Army Corps of Engineers constructed Oak Ridge, a new, secure city surrounded by a barbed-wire fence. The government built four major installations at Oak Ridge Reservation to produce the special radioactive materials needed for atomic weapons: 

• Y-12 plant (now known as the Y-12 National Security Complex) was created to enrich uranium
• K-25 site (now known as the East Tennessee Technology Park Complex) was created to enrich uranium
• S-50 site was created to enrich uranium
• X-10 site (now known as the Oak Ridge National Laboratory) was created to demonstrate processes for producing and separating plutonium

After WWII, the U.S. government used the facilities for nuclear research and production projects vital to national security. Over the years, activities at the Oak Ridge Reservation generated and released radioactive and chemical waste that contained various toxic metals, chemicals, and radionuclides. Some wastes remained in disposal sites on the reservation, and some pollutants were released into the nearby environment.

ATSDR Comes to the Oak Ridge Reservation

In 1989, the U.S. Environmental Protection Agency (EPA) added the Oak Ridge Reservation to the National Priorities List (NPL) of sites and facilities that pose a sufficient threat to human health or the environment to warrant cleanup. The U.S. Department of Energy is cleaning up the Oak Ridge Reservation under a Federal Facility Agreement with the EPA and the Tennessee Department of Environment and Conservation.

The Agency for Toxic Substances and Disease Registry (ATSDR) joined the public health work at the Oak Ridge Reservation in 1991. ATSDR is the principal federal public health agency charged with evaluating the human health effects of exposure to hazardous substances in the environment from hazardous waste and environmental spills. ATSDR assessments determine whether community members could potentially be at risk of harmful health effects from eating, drinking, breathing, or in any way contacting toxic releases away from the Oak Ridge Reservation. In Oak Ridge and surrounding communities, ATSDR worked with community members, civic organizations, and other government agencies to evaluate their health concerns about toxic releases from the Oak Ridge Reservation into off-site communities.

ATSDR Responds to Community Needs

During the two decades that ATSDR evaluated the health effects of releases of hazardous substances from the Oak Ridge Reservation and responded to more than 500 community health concerns, we responded to community needs by conducting or creating

• 150 community meetings
• 12 informational brochures
• 9 public health assessments
• 9 health education sessions for physicians and community members
• 4 health consultations
• 4 videos on public health assessments
• 4 scientific journal articles (published by ATSDR staff and members of the science panel)
• 1 medical data review
• 1 exposure investigation
• 1 science panel

ATSDR Findings

From 1991–2012, ATSDR evaluated the possible health effects of exposure to toxic substances released by the activities at the Oak Ridge Reservation. Some of the key findings are:

• Mercury in East Fork Popular Creek
  In its 1993 evaluation of East Fork Poplar Creek, ATSDR found that soil and sediment in two areas were contaminated with levels of mercury that pose public health concerns. In 1995 the agency provided recommendations and guidance on the mercury clean-up to the Department of Energy.
• PCBs and Watts Bar Residents
  The Watts Bar exposure investigation for PCBs, completed in 1998, found that PCB levels in area residents who eat large amounts of fish from the Watts Bar Reservoir were the same as levels in most of the fish-eating population. However, to minimize exposure to PCBs, ATSDR concurred with the fish advisory issued by the Tennessee Department of Environmental Control. The fish advisory recommends refraining from eating some types of fish and limiting others, especially for pregnant women and small children.
• Cancer
  The health consultation analyzing cancer data for 42 different cancer types in the 8 counties surrounding the Oak Ridge Reservation found no consistent pattern in cancer occurrence.
• Oak Ridge Reservation Contaminants
  In 8 public health assessments conducted for the Oak Ridge Reservation, scientists found that potential current and past off-site exposure to contaminants released from the reservation were below levels that cause health effects. This indicated that no further evaluation of health outcome data was needed.  
• Mercury from the Y-12 Facility
  The final public health assessment on mercury released from the Y-12 facility, published in 2012, found that current exposure to mercury from the facility was not harmful to health. The assessment also found that at different times in the past, children or pregnant women could have been exposed to amounts of mercury that are potentially harmful to health. Not enough environmental monitoring data exist to determine health effects from breathing mercury, swallowing mercury in creek water, or eating fish contaminated by mercury during specific periods during the 1950s and 1960s.
• Limitations
  Not enough environmental data exists for ATSDR to determine the amount of potential exposure for the following past releases:
  • Potential effects on the thyroid of persons who were under the age of 18 when exposed to I-131 released from X-10 from 1944 to 1956.
  • Potential for temporary respiratory irritation in sensitive persons living in the Sugar Grove and Union/Lawnville communities following short-term (acute) exposure to fluoride and hydrogen fluoride from the large, sudden UF6 releases in the 1940s and 1950s during accidents and equipment maintenance at the K-25/S-50 site.
  • Health risk from exposure to dioxins in fish.

ATSDR assessments and evaluations indicate that additional epidemiology studies or medical monitoring are neither warranted nor scientifically appropriate. Now residents of these communities can have confidence that they are not currently exposed to toxic substances that may cause harmful health effects.