CDR Joseph L. Hughart, MPH
Deputy Director, Office of Federal Programs
Agency for Toxic Substances and Disease Registry
1600 Clifton Road
Atlanta, GA 30333
(404) 639-0730
email: jxh8@cdc.gov

Although the Superfund program is primarily known for its environmental clean up mandate, there are a number of public health activities that must be conducted at all Superfund sites by the Agency for Toxic Substances and Disease Registry (ATSDR), an Operating Division of the U.S. Department of Health and Human Services. These activities include public health assessments of sites where hazardous substances have been released into the environment, and if necessary, follow-up health activities such as epidemiologic studies, exposure registries, and health surveillance programs.

ATSDR currently conducts CERCLA public health activities at 25 sites operated by DOE. ATSDR and DOE coordinate these activities through DOE's Office of Environmental Restoration and Office of Environment, Safety, and Health. ATSDR has assessed about half of these sites to date. Most DOE sites require no further health follow-up. However, ATSDR has found what appears to be increased rates of lung cancer and kidney disease at the Monticello Mill Tailings site in Utah that may be related to exposure to radon and uranium released into the community from the mill. ATSDR is considering conducting epidemiologic studies to evaluate this potential association. ATSDR is also initiating epidemiologic studies, a radiation exposure subregistry, and annual medical examinations for people exposed to Iodine-131 released from the Hanford Reservation in the late 1940s and early 1950s.

ATSDR also provides health consultations to DOE, EPA and States to assist in developing cleanup programs that adequately protect public health in a cost-effective manner. Working together, these agencies saved $39 million in cleanup funds at Oak Ridge by raising the cleanup level of mercury in sediments in East Fork Poplar Creek.

The U.S. Department of Energy's Environmental Restoration Program is driven significantly by clean up mandates defined in the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA, or "Superfund"), and its attendant environmental regulations under Volume 40 Part 300 of the Code of Federal Regulations. However, a less well known aspect of CERCLA involves public health activities mandated under section 104(i) of that law [1]. Section 104(i) established the Agency for Toxic Substances and Disease Registry (ATSDR) under the U.S. Department of Health and Human Services, and requires ATSDR to conduct a broad range of public health activities at CERCLA sites, including DOE facilities subject to CERCLA.

ATSDR's mandated activities under CERCLA can be divided into two broad categories: substance-specific activities and site-specific activities. Substance-specific activities include a requirement for ATSDR to develop a list of hazardous substances of public health concern most commonly found in the environment at Superfund sites; to develop toxicological profiles of those substances that describe the latest peer-reviewed scientific evidence about potential adverse health impacts from exposure to those substances; and to develop a toxicological research program in conjunction with the National Toxicology Program to address gaps in knowledge about the health effects of exposure to the substances.

To date, ATSDR has reviewed environmental monitoring data for 25 DOE Superfund sites; compiled a list of hazardous substances of public health concern commonly found at those sites; and has identified 14 hazardous substances for development of toxicological profiles [2]. In 1997, ATSDR completed draft toxicological profiles for uranium (including depleted uranium), and for ionizing radiation (a compilation of several substances posing ionizing radiation hazards), and has made those profiles available to the public for review [3]. In 1999, ATSDR plans to initiate toxicological profiles on Cesium 137, Iodine 131, Strontium, and Cobalt. ATSDR's toxicological profiles are available in print from the National Technical Information Service; and are available on CD ROM under an agreement with Lewis Publishers [5]. ATSDR is currently in the process of placing the toxicological profiles on the Internet.

ATSDR's site-specific activities include health consultations, available on request to government agencies, on a broad range of issues involving human exposure to hazardous substances in the environment, and a series of public health activities mandated for sites subject to CERCLA where hazardous substances have been released into the environment.

The mandated activities begin with a public health assessment of the site. ATSDR is required to conduct public health assessments at sites listed on, or proposed for listing on, the U.S. Environmental Protection Agency's (EPA's) National Priorities List (NPL). ATSDR may also conduct public health assessments at sites where hazardous substances have been released into the environment, and there is some basis for concern about potential human exposure to those substances, as a result of a petition from the public. ATSDR has assessed over 1,400 sites nationwide under the Superfund program [6]. Twenty-five of the sites that ATSDR must assess are operated by DOE.

A public health assessment is an evaluation of existing information about the nature and extent of environmental contamination, potential exposure pathways, populations susceptible to exposure, and potential exposure levels to determine whether exposures should be reduced, or whether additional information on exposure or health impacts is needed and should be obtained.

Following is a summary of ATSDR public health assessments at DOE sites.

If the results of a public health assessment indicate that additional information about health impacts is needed and should be obtained, ATSDR is required to conduct a pilot health study to determine whether rates of diseases that may be related to exposure to hazardous substances released from the site are elevated; to determine whether a full epidemiologic study is feasible; and to determine the most efficient and effective statistical method for conducting the study. ATSDR has determined that pilot health studies are needed at the Maywood and Monticello sites [7,8]. Preliminary results of a pilot health study in a community adjacent to the Maywood site reflected an elevated rate of brain cancer in elderly females. ATSDR is currently evaluating the results of that study to determine whether additional investigations are needed to determine the association between brain cancers and contaminants released from the site. Results of the public health assessment for the Monticello sites indicated that members of the Monticello community had been exposed to radon and uranium released from the mill at levels that may have exceeded health guidelines, and that rates of two plausible diseases (lung cancer and kidney failure) may be elevated. In FY 1998, ATSDR will initiate pilot health studies to determine whether the elevated rates can be confirmed; whether a full epidemiologic investigation is needed; and if it is, the appropriate design for the investigation.

Based on the results of public health assessments for the Hanford Superfund sites, in 1997 ATSDR initiated a full epidemiologic investigation of adverse birth outcomes in a population exposed to Iodine-131 released into the air from the Hanford Reservation in the 1940s and 1950s [9]. Preliminary results from that study are expected in 1999.

ATSDR is also required under CERCLA to establish and maintain the National Exposure Registry to track a broad range of biologically plausible diseases in populations exposed to hazardous substances released into the environment. The National Exposure Registry is divided into substance-specific subregistries. Subregistries have been established for populations exposed to Trichloroethylene, Trichloroethane, Dioxin, and Benzene. As a result of the Hanford public health assessments, in FY 1998 ATSDR is establishing a Radiation Subregistry to track adverse health outcomes in a cohort of 14,000 people exposed to Iodine-131 released from the Hanford site in the 1940s and 1950s [9].

Under CERCLA, ATSDR is required to provide health surveillance services to populations exposed to hazardous substances released into the environment when public health assessments, epidemiologic studies, or other investigations indicate that the exposures exceeded health guidelines. In 1998, ATSDR is initiating a health surveillance program for the Hanford "Downwinders" described above [9]. The program will consist of annual medical examinations for thyroid disease, and will be made available to the cohort of 14,000 people believed to have had the highest exposures during the 1940s and 1950s.

One of ATSDR's most popular services with communities and DOE Operations Offices is the health consultation. ATSDR provides health consultations on request to government agencies to respond to questions about human exposure to hazardous substances in the environment. ATSDR consultations on tritium in ground water near Los Alamos [10], and on milk and garden produce in the vicinity of Fernald [11], have helped communities obtain an independent, scientific evaluation of site-specific health issues, and have helped to bridge the credibility gap currently existing between many DOE sites and adjacent communities. In many cases, the consultations have laid to rest long-standing community health concerns. Health consultations are usually inexpensive, and conducted within a short time frame, and are therefore one of the most efficient and effective services that ATSDR can provide DOE's Environmental Restoration program. At Oak Ridge, ATSDR provided health consultations on clean up levels for mercury in sediment in the East Fork of Poplar Creek [12]. These consultations helped bring DOE, EPA, the State, and community members together to agree to raise the clean up level from 50 ppm to 400 ppm, resulting in substantial savings in clean up costs for DOE (savings reported to ATSDR are in excess of $39 million).

Under sections 120 and 107 of CERCLA, DOE is financially "liable" for the costs of ATSDR's mandated activities at DOE Superfund sites. ATSDR and DOE established a Memorandum of Understanding in 1992 to define procedures and responsibilities for conducting the ATSDR mission at DOE sites, and to establish a mechanism to transfer funds from DOE to ATSDR to meet the CERCLA liability requirement [13]. ATSDR's annual budgets for activities at DOE sites range from $4.5 million to $8.0 million, but beginning in FY 1998, those budgets increased to $17.1 million in response to the need to conduct a Radiation Subregistry and medical monitoring for thyroid disease in populations exposed to radiation released from Hanford.

Over the years, several myths have developed among staff at some DOE Operations and Headquarters offices about ATSDR's mission as it relates to DOE facilities. One of the most common myths is that DOE sites represent a large portion of ATSDR's workload, and budget, and therefore ATSDR has a vested interest in prolonging activities at DOE sites. DOE sites represent less than 2% of ATSDR's site-specific workload, and funding provided by DOE to ATSDR represents only about 7% of ATSDR's annual budget. Like DOE, ATSDR's workload continues to increase while resources (funding and staff) have remained fairly level over the past few years. It is not in ATSDR's interest or plans to prolong activities at DOE sites any longer than necessary.

Another myth is that meeting the CERCLA liability requirement for ATSDR's activities consumes a sizeable portion of DOE's Environmental Management budget. Since 1992, ATSDR's activities have represented less than one-tenth of one percent of funding provided to DOE for Environmental Management activities.

A third myth is that ATSDR's activities must compete with other DOE clean up activities for funding. This is prohibited under section 120(a)(2) of CERCLA.

A fourth myth is that ATSDR's activities are somehow at variance with the goals of the Environmental Restoration program, and may raise undue community concerns about health impacts. More often than not, ATSDR's health consultations and public health assessments have laid long-standing community health concerns to rest, and ATSDR's health consultations have the potential to provide DOE with significant savings in clean up costs.

DOE's Environmental Management Program exists to address a major social issue in the United States today: the mitigation of a long history of environmental contamination. Although the activities which resulted in that contamination occurred during a period of our nation's history when pressing national security concerns outweighed environmental concerns, the current social problem cannot and will not be addressed by environmental clean up activities alone. Communities adjacent to Superfund sites demand, and have a legal right to, public health services under CERCLA. The challenge for DOE and for ATSDR, working as partners, is to insure that those services are carried out as efficiently and effectively as possible.

1. Comprehensive Environmental Response, Compensation and Liability Act, 42 USC Sections 9601 - 9675, 1980.
2. Internal Correspondence, Division of Toxicology, ATSDR, 1997.
3. Toxicological Profile for Ionizing Radiation (Draft for Public Comment), Division of Toxicology, ATSDR, Atlanta, GA, 1997.
4. Toxicological Profile for Uranium, Including Depleted Uranium (Draft for Public Comment), Division of Toxicology, ATSDR, Atlanta, GA, 1997.
5. ATSDR's Toxicological Profiles on CD ROM, Lewis Publishers, Boca Raton, FL, 1997.
6. Report to Congress: 1993, 1994, 1995, Office of Policy and External Affairs, ATSDR, Public Health Service, U.S. Department of Health and Human Services, Atlanta, GA, 1996.
7. Public Health Assessment for Maywood Chemical Company, New Jersey Department of Health and the Division of Health Assessment and Consultation, ATSDR, Atlanta, GA, 1990.
8. Public Health Assessment for Monticello Mill Tailings and Residential Properties, Division of Health Assessment and Consultation, ATSDR, Atlanta, GA, 1997.
9. Public Health Assessment for the Hanford 200 Area (Initial Release), Division of Health Assessment and Consultation, ATSDR, Atlanta, GA, 1997.
10. Health Consultation on Tritium Contamination in Area Groundwater Wells, Los Alamos, New Mexico, Division of Health Assessment and Consultation, ATSDR, Atlanta, GA, 1995.
11. Health Consultation on Milk Produced Near the Fernald Environmental Management Project, Division of Health Assessment and Consultation, ATSDR, Atlanta, GA, 1995.
12. Health Consultation on Proposed Mercury Clean-Up Levels for the East Fork Poplar Creek Flood Plain Soil, Division of Health Assessment and Consultation, ATSDR, Atlanta, GA, 1995.
13. Memorandum of Understanding Between the Agency for Toxic Substances and Disease Registry and the U.S. Department of Energy, Office of Environment, Safety and Health and Office of Environmental Management, November 1992.