3
Scientific Program Assessment: Agency for Toxic Substances and Disease Registry

The Agency for Toxic Substances and Disease Registry (ATSDR) was established and operates under the mandates of the 1986 amendments to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, commonly known as the Superfund law). Memoranda of Understanding (MOUs) between ATSDR and the Department of Energy (DOE) were signed in 1990, 1992, and 1997. In 2000, rather than establishing separate agreements with the three agencies of the Department of Health and Human Services (HHS) involved in the Worker and Public Health Activities Program, ATSDR was added to the MOU that updated the working arrangements between DOE, the National Institute for Occupational Safety and Health (NIOSH), and the National Center for Environmental Health. This MOU expired at the end of FY 2004. A new MOU was proposed in April 2005 and is currently in negotiation between HHS and DOE.

To evaluate the quality of the programs from the viewpoint of science and public policy, the committee used a sampling strategy that reviewed selected studies from three DOE sites and, in some cases, products that were not site-specific (see detailed description of strategy in Chapter 1). Briefly, the selection rationale took into account the following factors:

  • The range of time over which health studies were initiated.

  • The number of workers involved as part of the program.

  • A variety of types of dissemination and communication challenges.

  • A variety of security challenges.

  • Size of the surrounding public community.

  • Geographic distribution of the sites.



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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services 3 Scientific Program Assessment: Agency for Toxic Substances and Disease Registry The Agency for Toxic Substances and Disease Registry (ATSDR) was established and operates under the mandates of the 1986 amendments to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, commonly known as the Superfund law). Memoranda of Understanding (MOUs) between ATSDR and the Department of Energy (DOE) were signed in 1990, 1992, and 1997. In 2000, rather than establishing separate agreements with the three agencies of the Department of Health and Human Services (HHS) involved in the Worker and Public Health Activities Program, ATSDR was added to the MOU that updated the working arrangements between DOE, the National Institute for Occupational Safety and Health (NIOSH), and the National Center for Environmental Health. This MOU expired at the end of FY 2004. A new MOU was proposed in April 2005 and is currently in negotiation between HHS and DOE. To evaluate the quality of the programs from the viewpoint of science and public policy, the committee used a sampling strategy that reviewed selected studies from three DOE sites and, in some cases, products that were not site-specific (see detailed description of strategy in Chapter 1). Briefly, the selection rationale took into account the following factors: The range of time over which health studies were initiated. The number of workers involved as part of the program. A variety of types of dissemination and communication challenges. A variety of security challenges. Size of the surrounding public community. Geographic distribution of the sites.

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services With these factors in mind, the committee selected three DOE nuclear operations sites—Hanford, Oak Ridge, and Los Alamos—as a subset of the total DOE sites on which it would focus its attention. In addition to this sampling strategy for site-specific aspects of the program, the committee requested and considered detailed information from the agencies on broad aspects of the program. In selecting ATSDR products to evaluate, the committee searched through web sites listing ATSDR research products. In addition, all agencies were asked to identify in writing work conducted under the MOU. Further queries were made to determine whether specific studies were conducted under the MOU. In addition to conducting an overview of the types of studies conducted under the MOU, the committee selected certain specific products for closer evaluation. ATSDR PROGRAM AREAS RELEVANT TO THE MOU ATSDR produces six principal products as specified in amendments to CERCLA: Public Health Assessments (PHAs) Health Studies Toxicological Profiles Medical Surveillance Exposure and Disease Registries Health Education and Promotion The committee evaluated the ATSDR DOE-funded program by evaluating ATSDR products listed at the ATSDR web site and through responses to information requests sent to ATSDR (2006) (see Table 3-1). The committee also specifically evaluated selected PHAs at the three committee-selected sites and a health study conducted at one of the sites. Toxicological Profiles developed with DOE funds were also evaluated. The metrics used to evaluate these products included assessment of their appropriateness to the DOE mission and their usefulness in informing the communities surrounding DOE sites of possible health hazards due to past and present activities of DOE. REVIEW OF SELECTED PUBLIC HEALTH ASSESSMENTS AT THE THREE COMMITTEE-SELECTED SITES As part of its evaluation of the appropriateness and scientific quality of ATSDR, the committee reviewed selected PHAs at each of the three sites designated in the committee sampling strategy, Hanford, Oak Ridge, and Los Alamos (see sampling strategy in Chapter 1). The ATSDR web site1 lists one PHA at Los 1 See http://www.atsdr.cdc.gov. Last accessed November 2006

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services TABLE 3-1 ATSDR Activities Under the MOUa(except when noted otherwise) Name of Product Type of Product Comments Public Health Assessments Assessments of potential community health hazards at DOE sites. ATSDR notes that PHAs are in-depth evaluations of data and information on the release of hazardous substances into the environment In 1992, there were 20 DOE sites on ATSDR’s work plan (19 DOE NPL sites + 1 petition site). ATSDR has completed 20 PHAs addressing 22 DOE sites Health studies Health studies can be divided into two basic types: those that are primarily exploratory in their approach (Type-1 studies), and those that require rigorous scientific methods to evaluate specific exposure-outcome relationships (Type-2 studies).bA health study consists of activities that use epidemiological principles to examine the occurrence of health conditions, exposure to harmful substances, or both, by systematically collecting, analyzing, and interpreting data Under CERCLA and when appropriate, ATSDR on the basis of health assessment results conducts pilot studies of health effects for selected groups of exposed individuals to determine the desirability of conducting a full-scale epidemiological or other health study Toxicological Profiles Toxicological Profiles characterize the toxicologic and adverse health effects information for the hazardous substance in question ATSDR provided the committee seven Toxicological Profiles funded entirely or partially by DOE: americium, cesium, cobalt, iodine, ionizing radiation, strontium, and uranium. ATSDR also noted in its response to the committee that two interaction profiles were funded by DOE Public Health Statements (PHSs) PHSs are stand-alone versions of Chapter One of the Toxicological Profiles. PHSs provide more extensive information than is found in the ToxFAQs and are written at an eighth-grade reading level Spanish versions available ToxFAQs Excerpted from the Toxicological Profiles; ToxFAQs are written at about eighth-grade level and are used to educate and inform the public in affected communities Spanish versions available

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services Health activities Health activities may include new studies, ongoing studies, medical screenings, and/or analysis of existing datasets   Surveillance activities Surveillance activities are described as the ongoing systematic collection, analysis, and interpretation of health data over time; these are essential to the planning, implementation, and evaluation of public health practice   Health consultations Health consultations are very focused and generally address one specific question. Requests come from DOE, EPA, state agencies, or impacted communities   Exposure investigations In exposure studies, biological samples such as blood or urine are assessed to see whether exposure to a particular hazardous material can be established   Exposure and disease registries A registry is a database that includes information about people with specific exposures or diseases   Health education and promotion CERCLA 104 (i)(14) mandates that ATSDR assemble, develop as necessary, and distribute appropriate educational materials on medical surveillance, screening, and methods of diagnosis and treatment of injury or disease related to exposure to hazardous substances See Chapter 5 for an evaluation of dissemination activities under the MOU aBased on ATSDR responses to committee questions received February 19, 2006. bSee http://www.atsdr.cdc.gov/HS/gd1.html. Last accessed July 2006. NOTE: EPA = U.S. Environmental Protection Agency; NPL = National Priorities List.

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services Alamos (the site itself) and that PHA was selected for review, consistent with the selection strategy. Three of the sites at Hanford were selected for review because the sites span the range from very contaminated (200-Area), to intermediate contamination (300-Area), to very low contamination (1100-Area) and the three PHAs reviewed represented the various stages of the PHA generation process from initial release (200 Area) to final assessment (1100-Area). The ATSDR web site lists a number of PHAs at the Oak Ridge reservation. The Y-12 site was selected because of a wide range of activities at the site over the years of its operation and because of the potential for uranium releases in the past. The TSCA incinerator PHA was selected for review as an assessment that evaluates the potential hazards of a “waste reduction and disposal operation.” The copies reviewed represented a range of stages in the PHA generation process including public comment versions and final versions. PDF versions of the reports were accessed on the ATSDR web site and hard copies of the reports were obtained from ATSDR. Public Health Assessments ATSDR has indicated to the committee that the criteria used to establish the order of priority for selecting DOE sites for assessment were published in the Federal Register (57 FR 37382, August 18, 1992). These criteria included the toxicity of the chemicals present, the site population, exposure pathways, health outcome data, and the plausibility of community concerns. Furthermore, in 1986, amendments to the Superfund law directed ATSDR to conduct a PHA at each of the sites on the Environmental Protection Agency’s (EPA’s) National Priorities List (NPL; ATSDR 2005a). See Annex 3A for selected language from the CERCLA legislation mandating PHAs at sites on the NPL. Many of the DOE sites evaluated by HHS are on the NPL. A health assessment determines whether people are being exposed to hazardous substances, and if so, the health assessors determine whether that exposure should be stopped or reduced. As the first step, ATSDR scientists review the extent of contamination at a site and how people might come into contact with that contamination. If the initial step indicates that individuals have or will come into contact with a hazardous substance, ATSDR scientists evaluate the risk of harmful effects from these exposures, with a focus on health impacts on the community as a whole. This phase of the assessment usually involves a comparison of the maximum levels of a given substance to which ATSDR estimates the public is exposed with various regulatory standards or non-regulatory guidance values for that substance that estimate what levels of exposure are safe. “Safe” generally is not viewed as an absolute absence of risk; rather, if any risk does exist, it is minimal. The PHA can also present conclusions about the level of the threat, if any, and can recommend ways to stop or reduce exposure to that threat. In the past,

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services CERCLA specifically exempted health assessments from peer review, but beginning in 1997, ATSDR began submitting DOE PHAs for peer review (ATSDR 2006). ATSDR notes that the health assessment process is an interactive one, with information solicited from local and federal governments as well as from members of communities during the Public Comment Period. The Public Comment Period allows the community to ask questions about the assessment as well as state concerns they may have with the initial PHA. While many of the questions posed to ATSDR by the public are responded to in writing by ATSDR in the final PHA, the committee is not aware of any independent evaluations performed to assess the objectivity or scientific merit of the responses to the public published in the final PHA. It should be noted that due to the short review period, the committee did not have sufficient time to review either the completeness or the scientific validity of the responses by ATSDR to the public comments that were included in the final PHAs reviewed. Hanford Site The committee reviewed PHAs at three sites on the Hanford Nuclear Reservation in southeast Washington State. The Hanford area was the site of plutonium production beginning with the Manhattan Project during the Second World War. The three sites reviewed are designated the 200-Area, which once housed the process that chemically separated uranium from highly radioactive uranium fuel rods produced in the 100-Area reactors; the 5.7-square-mile 300-Area, which once fabricated uranium fuel rods that were irradiated in the 100-Area to produce plutonium; and the 1.2-square-mile 1100-Area that borders the Columbia River and is the closest site to the community of Richland, Washington. Public Health Assessment for Hanford 200-Area (DOE Initial Release Version July 16, 1997) The 200-Area at Hanford is one of four NPL sites designated at the Hanford Nuclear Reservation (ATSDR 1997b). There are too many toxic substances stored on the 200-Area site to be listed in this short review, but such substances include many radiological and toxic solvent by-products of plutonium production. Radioactive wastes dissolved in chemical solvents have been stored in tanks with varying long-term containment integrities. Soils and water on the site have been contaminated at various times, and air releases of radioactive materials have occurred. Low-level wastes are also stored on the 200-Area, and the site even contains some naval submarine reactor compartments that eventually will be buried. Off-site contamination has also occurred from the 200-Area. The ATSDR assessment includes a thorough description of the history of the site and the types of toxic materials that are distributed throughout the site. The assessment includes a section comparing exposure levels with measures of toxicity such as minimal risk levels and reference doses.

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services On-site Hazard Evaluation This ATSDR PHA concludes that the 200-Area of the Hanford site poses a health hazard to workers on the site itself from site-related contaminants released to the air, soils, and groundwater; specifically the PHA notes that on-site soil levels of radiological contaminants present a hazard to workers. Each of the operable units or process areas in the 200 East and West Areas has produced at least one completed exposure pathway with respect to on-site workers. The groundwater is not available to humans, although small amounts of the contaminants might migrate to the Columbia River. The 200-Area is part of lands held in trust for some Native American tribes. Although the area is undergoing remediation, current plans will not release this area for public use. Off-site Hazard Evaluation The location and buffer zone around the area have prevented completion of most of the potential exposure pathways extending off-site; the only exceptions are the atmospheric pathway and the Columbia River pathway. The assessment notes that currently available scientific evidence indicates that radiological contaminants released from the 200-Area are not expected to cause adverse health effects for the communities surrounding the sites. While ATSDR believes this area may have posed a public health risk in the past, inadequate data and the lack of documented off-site contamination in the past directly attributable to the 200-Area have not allowed the agency to assess past public health risks. ATSDR also notes that it found the available health outcome data for Washington State and the area around Hanford to be insufficient for this study. In this regard, ATSDR proposed three health-related projects. One of these, the Hanford Fetal Death and Infant Mortality Study, is reviewed later in this chapter as an example of an ATSDR health study. Public Health Assessment for Hanford 300-Area (DOE Initial Release Version July 16, 1997) The 300-Area is on the NPL because “on-site groundwater is contaminated with uranium and trichloroethelene” (ATSDR 1997a). Soils on-site contain polychlorinated biphenyls (PCBs), trichloroethylene (TCE), cobalt, and uranium. DOE has detected uranium in springs both around the site and in the Columbia River, while strontium and uranium are present in vegetation around the site. This ATSDR PHA concludes that there is no health hazard to the public because “… the public cannot come in contact with the contaminants identified in the [on-site] water and the soil.” Although the public is concerned about releases of radioactive materials to publicly available lands and waters, the PHA concludes that such releases have not occurred from the 300-Area. The 300-Area is part of lands held in trust for some Native American tribes, and ATSDR notes

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services that if the land were returned for tribal use, “ATSDR would need to evaluate the public health implications of contaminants present on site at that time.” Public Health Assessment for Hanford 1100-Area (DOE November 20, 1995) The 1.2-square-mile 1100-Area at Hanford is on the NPL because “on-site wells contain volatile organic compounds that include trichloroethylene” (ATSDR 1995). On-site soils are contaminated with heavy metals and PCBs. Possible exposure routes on-site include direct contact with or accidental ingestion of contaminated groundwater and soil. The Yakima River borders the site and is a main fishing source for the Yakima Indian Reservation (ATSDR 1995). The 1100-Area currently serves as a vehicle maintenance and general support area for DOE’s 560-square-mile Hanford Reservation. Because of its proximity to the city of Richland, Washington, good amounts of data on the area have been collected. This PHA concludes that the 1100-Area poses no apparent public health hazard because no one (off-site) can come in contact with these contaminants; the contaminants identified on-site were not identified off-site. The PHA further concludes that there are no known past or current completed exposure pathways to the local population and that there are unlikely to be completed exposure pathways in the future. ATSDR notes that community health concerns relate mainly to radioactive releases from other areas at Hanford and not to the 1100-Area, where radioactive contamination has not been detected. Oak Ridge Reservation ATSDR scientists have conducted or are conducting PHAs on the following releases: Y-12 releases of uranium, Y-12 releases of mercury, X-10 release of iodine-131, X-10 release of radionuclides from White Oak Creek, K-25 releases of uranium and fluoride, and PCBs released from all three facilities. ATSDR’s assessment of cancer incidence in counties adjacent to Oak Ridge Reservation shows that higher rates of some cancers and lower rates of other cancers were found in several of the counties for which data were analyzed, although there was no consistent pattern in cancer occurrence. ATSDR concludes that radionuclides released from X-10 via White Oak Creek are not a public health hazard for people who lived near or used the Clinch River or Lower Watts Bar Reservoir in the past or present. ATSDR also found that the TSCA incinerator releases very small amounts of contaminants into the environment, but notes that the amounts are far below levels associated with health effects.2 The committee reviewed the completed Y-12 uranium PHA at Oak Ridge and the completed Oak Ridge TSCA incinerator PHA. 2 See http://www.atsdr.cdc.gov/HAC/oakridge/phact/index.html. Last accessed July 2006.

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services Public Health Assessment for Oak Ridge Reservation: Y-12 Uranium Releases (January 30, 2004) In 1942, the federal government established the Oak Ridge Reservation (ORR) in Tennessee as part of the Manhattan Project to produce special nuclear materials for weapons. ORR was added to the EPA’s NPL in 1989 due to the presence of radioactive and non-radioactive wastes on the site. Three of the four facilities built in 1942 were created to enrich uranium. One such facility, designated Y-12, is the subject of this extensive PHA. The 825-acre Y-12 plant, about 2 miles south of downtown Oak Ridge, was used initially to electromagnetically enrich uranium, then to enrich lithium-6 using column-exchange technology, and then to fabricate components for thermonuclear weapons. After the Cold War the mission shifted to weapons disassembly and renovation. The site is a primary storage site for enriched uranium. The town of Oak Ridge, which peaked in population at 75,000 in 1945, has stabilized at about 27,000 people. This PHA considered detailed pathways of exposure to uranium that could result in inhalation or ingestion of uranium off-site. Exposure values for a reference location, the Scarboro Community, that would have received the highest uranium concentrations in past exposures, were also evaluated. In some past exposures involving ingestion pathway, minimal risk levels (MRLs) were exceeded for some age groups.3 When MRLs were exceeded, the ATSDR conducted further evaluations of toxicological end points to reach a conclusion regarding the potential for human health hazard at those exposure levels. An overall conclusion of ATSDR’s evaluation of both past and current exposures to uranium released from the Y-12 plant was that off-site exposures to uranium were too low to be a health hazard for either radiation or chemical health effects. Public Health Assessment for TSCA Incinerator at Oak Ridge Reservation (December 2005 Version). This PHA evaluates environmental exposures to contaminants released from the TSCA incinerator at the ORR in Roane County, Tennessee. DOE contractors currently operate the incinerator at the facility currently known as the K-25 site. The TSCA incinerator, which began operation in 1991, destroys organic chemicals in waste and reduces the volumes of waste materials that contain low-level radioactive contamination. This PHA focuses on direct inhalation of airborne contamination, the most likely pathway of exposure. The authors note that a separate PHA will consider the possibility of contamination in other media, such as surface water, soils, and food items (ATSDR 2005b). This PHA considered the incinerator design and operation, the wastes treated, and the air emissions from the plant. Stack tests were evaluated to identify and measure materials that were released to the environment. A conclusion was that 3 An MRL is an estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse non-cancer health effects over a specified duration of exposure.

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services measured emission rates were lower than limits established in health-protective environmental permits. Dispersion models developed by Tennessee, ATSDR, and DOE were considered; ATSDR concludes that the incinerator does not emit contaminants at levels that would cause health problems. ATSDR also considered air sampling data since 1991 and concluded that emissions have minimal air quality impacts beyond the ORR boundary. The assessment further concludes that exposures to contaminants are possible but not at levels of public health concern. The completed TSCA PHA incorporates a thorough analysis of contaminants released from the incinerator and considers the pathways by which these contaminants might affect the surrounding communities. The demographics of the population living in the vicinity of ORR are also carefully considered. The PHA evaluated was a final version and key findings are highlighted in text boxes in understandable language. Graphics are user friendly and an appendix is included with responses to public comments. Los Alamos National Laboratory The committee reviewed one PHA for Los Alamos National Laboratory. Public Health Assessment for Los Alamos National Laboratory (DOE Public Comment Version April 26, 2005) Los Alamos National Laboratory (LANL) is a 28,000-acre active facility owned by DOE and operated by Los Alamos National Security, LLC, a consortium involving the University of California and three companies (ATSDR 2005a). Approximately 22,000 persons live within a 10-mile radius of LANL. Past activities have released chemical and radioactive wastes into the soil, air, and water around LANL. LANL is investigating the contamination as a first step to monitor hazardous materials and to restore the environment and mitigate past releases. ATSDR has reviewed past, current, and potential future exposures at LANL. For exposures before 1980, ATSDR has made no determination regarding potential health effects because data on pre-1980 LANL exposures were not yet available for evaluation. ATSDR’s review of information since 1980 resulted in a determination that no harmful exposures to the public are presently occurring, and they are not expected to occur in the future due to chemical or radioactive contamination in the groundwater, surface water, soil, air, or biota around LANL. All levels of radioactive and non-radioactive substances that were found to exist at maximum concentrations greater than ATSDR health-based comparison values were judged by ATSDR to be insufficient to result in adverse human health effects. General Evaluation of PHAs Reviewed ATSDR has completed 20 PHAs addressing 22 DOE sites on EPA’s NPL. ATSDR is currently working on five remaining DOE sites, Hanford, Brookhaven

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services (document released for public comment), Los Alamos (document released for public comment), Savannah River, and Oak Ridge. (Because Oak Ridge is complex, ATSDR is preparing public health assessments for each exposure concern: one assessment is completed [Y-12], three are at public comment [TSCA incinerator, White Oak Creek, and Off-Site groundwater], and five others were in the draft process but stopped due to funding limitations [ATSDR 2006]). These assessments evaluate the levels of toxic substances on the sites and possible pathways that might expose the community to the toxic substance. The focus of ATSDR’s PHAs is the evaluation of possible off-site health effects on communities rather than individuals. Based on the PHAs reviewed by the committee, these assessments appear to provide good detail on concentrations of potentially toxic substances on the sites and potential pathways for exposure of communities surrounding the sites to these toxicants. The off-site exposures from hazardous substances present on the sites are usually extremely low or non-existent. In general, maximum estimated exposures of the communities are compared to guidance values and standards such as ATSDR MRLs; EPA maximum contaminant levels and reference doses; toxicology-based lowest-observed-adverse-effect levels; no-observed-adverse-effect levels; and similar values (see abbreviations and acronyms). If a range of exposures is indicated, the PHAs often will use the highest estimated dose as a “conservative” measure when making comparisons with toxicology values. The PHAs, however, are not in themselves quantitative studies of exposure and health effects. In general, the maximum exposures of the communities adjacent to a site are so low that a finding of no adverse human health effect is likely. One aspect of the PHAs worth noting is that if maximal exposures to the community are below a certain level, a judgment is made that no risk to the community is likely to exist. This may be true of many non-radiological exposures. However, if one accepts a linear-no-threshold (LNT) model for radiation exposure risk, then there is no level of radiation exposure that does not present some risk, although that risk may be very small (NRC 2006). This committee takes no position on whether the extrapolation of human cancer risks from established data to lower doses (where radiation health effects are not detectable by epidemiological methods) should be LNT, supralinear (a greater health risk than would be predicted by the LNT), or sublinear with a threshold below which there is no effect. The committee notes, however, that ATSDR states that conservative (meaning protective) assumptions are made in the development of PHAs. The use of a threshold for radiation risk appears to be a departure from this conservative stance. Using the Oak Ridge Y-12 Uranium Releases PHA as an example, ATSDR concludes “… that doses below the radiogenic cancer comparison value of 5,000 mrem over 70 years are not expected to result in adverse health effects at Oak Ridge (ATSDR 2004a). 5,000 mRem corresponds to 50 mSv. This conclusion is inconsistent with the principles of the conservative approach to the protection of

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services public health that the agency asserts it applies in the evaluation of radioactive agents and ignores a fundamental epidemiological concept that small relative risks can yield significant adverse health outcomes if the population exposed is large. Recent epidemiological studies of long-term exposure to high-LET (linear energy transfer) radiation (Field et al. 2000; Darby et al. 2005; Krewski et al. 2005, 2006), occupational health analyses utilizing the data available from 15 countries (Cardis et al. 2005), National Academies reports (NRC 1990, 1999, 2006), and an evaluation of the LNT for ionizing radiation by the National Council on Radiation Protection and Measurements (NCRP 2001) and use of the LNT by the Biological Effects of Ionizing Radiation (BEIR) VII committee provide contemporary and continuing support for a conservative assumption of no threshold. In addition, most government agencies, including those with regulatory responsibilities, use this principle. HEALTH STUDIES ATSDR has also conducted “health studies” when the initial findings of a PHA indicated that further follow-up was needed. A health study consists of activities that use epidemiological principles to examine the occurrence of health conditions, exposure to harmful substances, or both, by systematically collecting, analyzing, and interpreting data (ATSDR 2006). In response to committee inquiries about projects completed since 1990, ATSDR listed the following Health studies: Hanford CAPI locating—completed March 1998. Hanford Mortality—completed August 1997; Final Report dated November 2000; International Journal of Hygiene and Environmental Health article dated 2001. Tatham, L.M., F.J. Bove, W.E. Kaye, and R.F. Spengler. 2002. Population exposures to I-131 releases from Hanford Nuclear Reservation and preterm birth, infant mortality, and fetal deaths. Int J Hyg Environ Health 205:41-48. Hanford Area School Follow-Up—Locating persons born in Adams, Benton, and Franklin Counties between the years 1940 and 1951. Completed July 1998. Hanford Medical Monitoring—name was changed to Hanford Community Health Project (HCHP). The HCHP was completed September 2005. A journal article is currently being edited. See http://www.atsdr.cdc.gov/hanford/healthcare/. Hanford Cohort—Final Report is being edited; journal article should be complete by July 2006. Hazardous Waste Workers—completed. Reports dated February 2000 and July 2002 Not site-specific. Fernald—University of Cincinnati—Final Report dated August 2001.

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services The committee reviewed a health study conducted at one of the three committee-selected sites: the Hanford Infant Mortality and Fetal Death Analysis (Tatham et al. 2002). The study met the criteria of being a study at one of the three sites represented in the committee’s selection strategy and was published in sufficient detail for committee evaluation. A preliminary, unpublished investigation of infant, neonatal, and fetal death rates in eastern Washington State found an increased rate of infant mortality in 1945 for counties exposed to “high” levels of iodine-131 (I-131) released from the Hanford facility compared to counties with “low” exposure. Populations living near the Hanford facility are known to have been exposed to I-131, with the highest releases occurring between December 1944 and December 1947. A subsequently published ATSDR health study (Tatham et al. 2002) was conducted to investigate the earlier finding of increased infant mortality. Estimates of I-131 dose levels at maternal residential address, defined by zip code, for an eight-county area surrounding the Hanford facility at the time of birth in 1945 and 1946 were assessed for possible associations with infant mortality, fetal death, and preterm birth. In addition, trends and causes of death between 1940 and 1952 were examined. The analysis included 72,154 births, 1,957 infant deaths, and 1,045 fetal deaths over the 13-year study period, and each birth and death record was assigned to one of four exposure groupings. This study found an increased risk of preterm birth in women who lived in counties that had relatively high estimated I-131 exposure in 1945 (OR = 1.6; 95% CI = 1.0-2.6).4 The association was stronger when the exposure occurred during the latter part of the pregnancy (OR = 1.9; 95% CI = 1.2-3.0). Infant mortality rates for areas further from the facility were higher than those for areas closest to the facility for most of the 13-year period, with the exception of 1945 and 1946 (high-exposure years). The report concludes that “I-131 exposure may be associated with preterm birth.” Furthermore, a modest increase in infant mortality was observed, supporting findings from the earlier investigation in 14 counties. Finally, the report concludes that further research on more contemporary populations may be warranted. There is limited information in the literature on I-131 exposure and pregnancy outcomes, and this study has the potential to provide valuable information. A major strength of the study is the nearly complete ascertainment of outcome data (i.e., births and deaths). However, there are a number of study limitations including possible misclassification of exposure as a result of uncertainties in the dose estimates that were derived from the Hanford Environmental Dose Recon- 4 OR = odds ratio. The odds of being exposed among diseased persons divided by the odds of being exposed among non-diseased persons. CI = confidence interval; an interval estimate of an unknown parameter, such as a risk.

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services struction Project (see Chapter 4); change in residence during the pregnancy; inadequate control of potential confounders (e.g., body mass index, mother’s education); and the use of multiple comparisons. General Evaluation ATSDR’s use of health studies when PHAs or other initial indicators suggest that a health hazard may exist is a logical transition to the use of standard epidemiological techniques to quantitatively evaluate potential hazards. The use of such studies also provides a bridge between the methodologies used by ATSDR and those used by NIOSH. The committee encourages the use of epidemiological methods, such as in study design and analytical approaches, similar to those employed by NIOSH while recognizing that the exposures of communities surrounding DOE sites (the ATSDR focus) must be estimated, while exposures of workers at the sites (the population studied by NIOSH) can sometimes be determined by radiation external and internal personal dosimetry measurements. ATSDR TOXICOLOGY PROFILES ATSDR also produces toxicological profiles of chemicals or radiological substances. The criteria for selecting toxicological profiles for development were published in the Federal Register in 1993 (58 FR 27286-27287, May 7, 1993). This publication also describes the approach that ATSDR uses to develop or update profiles. Between August and December 1996, ATSDR developed and finalized a list of the top 12 radioactive substances at DOE sites with input from DOE. ATSDR identified seven radiation ToxProfiles™ as being funded or partially funded by DOE. These profiles included six radiological substances that one might expect would be present at some DOE sites and one profile of ionizing radiation itself. Americium, cesium, cobalt, iodine, strontium, and ionizing radiation profiles were funded by DOE. The uranium profile was developed using CERCLA funds but updated in FY 1999 using DOE funding. In general, the toxicological profiles address community needs and concerns. Many of the profiles have a “Quick Reference for Health Care Providers” section immediately following the preface and preceding the table of contents. This section is intended to attract the attention of health care providers and to guide them to selected chapters and sections of the report that should be of interest and value to the health care professional. In addition, contact and referral information is provided for use by health care professionals. Chapter 1 of the reviewed toxicology profiles is a public health statement. This chapter is written in such a way as to be of value to the lay reader. Using the cesium toxicology profile as an example, headings include “What is Cesium?”

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services “How Might I Be Exposed to Cesium?” “How Can Cesium Affect My Health?” (ATSDR 2004b). Chapter 2, which discusses relevance to public health, is also written for the lay reader and “evaluates, interprets, and assesses the significance of toxicity data to human health” (in the case of the Ionizing Radiation Toxicological Profile, Chapter 2 departs from this structure and is about the “principles of ionizing radiation”) (ATSDR 1999). Chapter 3, on health effects, is more technical, and specific health effects are reported by type of health effect, route of exposure, and length of exposure; both human and animal studies are reported when available. Toxicological profiles undergo internal and external review and are made available for public comment prior to completion. General Evaluation The committee concludes that the seven DOE-funded ATSDR radiation toxicological profiles are relevant to DOE’s mission and provide in-depth evaluations of the characteristics of the radiological material profiled. The profiles of specific radiological substances, in general, provide an overview of the knowledge base on the potential radiological hazards present at some DOE sites. The profile on the toxicology of ionizing radiation in general, a potential hazard at many DOE sites, is a useful supplement to many reports on this subject, such as the National Research Council’s BEIR series and the United Nations Scientific Committee on the Effects of Atomic Radiation series, and International Agency for Research on Cancer publications 75 and 78. Extensive information is presented in the technical chapters from the biological and epidemiological literature. The physics and dosimetry nomenclature are described thoroughly. The format of the first two chapters is designed to be understandable by both the public and health care providers in communities surrounding the sites, and the committee considers this to be of value to DOE and the public. The committee includes more detail on the origin and intent of toxicological profiles (ATSDR 2006) in Annex 3B. OTHER ATSDR PRODUCTS For a tabulation of the range of ATSDR products see Table 3-1. General descriptions of selected additional products are provided below. Medical Surveillance CERCLA mandates, when appropriate, the testing of exposed individuals, epidemiological studies, periodic survey and screening programs, or other assistance to determine relationships between exposure to toxic substances and illness. In addition to the PHA and health studies already mentioned, ATSDR also

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services provides health consultations (HCs). HCs are very focused and generally only one specific question. Requests for consultations come from DOE, EPA, state agencies, or impacted communities. Consultations can address exposure issues as they arise after PHAs are completed. Examples include Paducah, Kentucky— consult on nickel and metal exposures from historic smelter operations; Maywood, New Jersey—consult on each residential property for elevated lead levels; W.R. Grace/Wayne, New Jersey—soil in children’s’ sand boxes. ATSDR consultations can also address questions for non-NPL sites: Alba Craft Lab, Ohio (Formerly Utilized Sites Remedial Action Program [FUSRAP])—residential soil cleanup levels; Cape Thompson, Alaska (FUSRAP)—cancer incidence rates; West Valley Demonstration Project, New York—reviewed Environmental Impact Statement at request of local tribe; Lawrence-Berkeley, California—confirmed and concurred with overall tritium risk assessment done by DOE (ATSDR 2006). Exposure Investigations In exposure investigations, biological samples such as blood or urine are assessed to see whether exposure to a particular hazardous material can be established. As an example, ATSDR has conducted an exposure investigation at Oak Ridge, one of the three committee-selected sites, assessing levels of PCBs and mercury in blood. In 1997, ATSDR screened more than 500 persons and obtained blood samples from 116 persons who were consuming fish from Watts Bar Reservoir. Of the 116 persons, 5 (4 percent) tested had PCB levels greater than 20 µg/L, which is considered elevated. In addition, one participant had a total blood mercury level greater than 10 µg/L, which is also considered elevated (ATSDR 2006). Exposure and Disease Registries CERCLA mandates that ATSDR, in cooperation with the states, establish and maintain a national registry of serious diseases and illnesses and a national registry of persons exposed to toxic substances. As an example, ATSDR maintains the National Exposure Registry (NER), which is a long-term effort that meets the need for collecting information concerning the potential impact of hazardous substances on human health. The registry is a listing of persons exposed to hazardous substances. It contains subregistries for specific substances. There are currently four active subregistries—TCE, trichloroethane, benzene, and dioxin. This exposure registry could be expanded to include other substances, One purpose of the NER is to help scientists understand how long-term exposure to hazardous substances may affect human health. Another purpose of the registry is to have a mechanism through which participants can be notified of the results of research related to their expo-

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services sure. The registry program carries out its mandate by creating a large database of similarly exposed persons. This database is used to facilitate epidemiological research in ascertaining any adverse health effects of persons exposed to low levels of chemicals over a long period. All data collected are confidential. Names and addresses are protected under the Privacy Act and are not released without written permission of the registrant.”5 Health Education and Promotion CERCLA mandates that ATSDR assemble, develop as necessary, and distribute appropriate educational materials on medical surveillance, screening, and methods of diagnosis and treatment of injury or disease related to exposure to hazardous substances through such means as the administrator of ATSDR deems appropriate. The committee evaluates communication efforts in Chapter 5 of this report. SUMMARY ATSDR is the source of a number of products, some of which are funded or partially funded by DOE, that have value for the program conducted under the MOU and are generally of a high quality. The PHAs and toxicological profiles are presented in such a way as to have potential value to the communities surrounding DOE sites. Some of this utility has been compromised by the public’s reaction to ATSDR’s use of a threshold for radiation effects in some of the PHAs. In 1997, ATSDR began submitting DOE PHAs for peer review. The committee supports the continued peer review of these documents in the future. An overview of ATSDR’s DOE-funded activities suggests that research priorities and project selection are appropriate, with the understanding that many of the priorities are mandated by CERCLA FINDINGS AND RECOMMENDATIONS 1. The PHAs are presented in such a way as to have potential value to the communities surrounding DOE sites. Some of this utility has been compromised by the public’s reaction to ATSDR’s use of a threshold for radiation effects. As a result, the committee recommends the following: In light of ATSDR’s mandate to adopt and apply conservative assumptions, the committee recommends that ATSDR reevaluate its use of a radiation risk threshold. 5 See http://www.atsdr.cdc.gov/NER/index.html. Last accessed July 2006.

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services 2. ATSDR has completed 20 PHAs addressing 22 DOE sites on EPA’s NPL. ATSDR is currently working on five remaining DOE sites, Hanford, Brookhaven, Los Alamos, Savannah River, and Oak Ridge. The committee concludes that the PHAs have potential value to the communities surrounding DOE sites and that the PHAs at the five sites that have already been initiated should be completed. As a result, the committee recommends the following: DOE funding of ATSDR activities at the five DOE sites should continue. ANNEX 3A CERCLA DIRECTIVE REGARDING PUBLIC HEALTH ASSESSMENTS SUBCHAPTER I—HAZARDOUS SUBSTANCES RELEASES, LIABILITY, COMPENSATION…. 9604. [CERCLA 104] Response authorities…. (i) Agency for Toxic Substances and Disease Registry; establishment, functions, etc…. (6) (A) The Administrator of ATSDR shall perform a health assessment for each facility on the National Priorities List established under section 9605 of this title…. (F) For the purposes of this subsection and section 9611 (c)(4) of this title, the term “health assessments” shall include preliminary assessments of the potential risk to human health posed by individual sites and facilities, based on such factors as the nature and extent of contamination, the existence of potential pathways of human exposure (including ground- or surface-water contamination, air emissions, and food chain contamination), the size and potential susceptibility of the community within the likely pathways of exposure, the comparison of expected human exposure levels to the short-term and long-term health effects associated with identified hazardous substances and any available recommended exposure or tolerance limits for such hazardous substances, and the comparison of existing morbidity and mortality data on diseases that may be associated with the observed levels of exposure…. ANNEX 3B ATSDR DESCRIPTION OF TOXICOLOGICAL PROFILES Information Provided to the Committee by ATSDR Regarding Toxicological Profiles Provide an examination, summary, and interpretation of a hazardous substance to determine its human health impact. Profiles also include guidance values known as MRLs, which are defined as estimates of daily human exposure to

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services a hazardous substance that are likely to be without appreciable risk of adverse, non-cancer health effects. MRLs are used as screening levels by health assessors to assist in decision making at hazardous waste sites. Succinctly characterize the toxicological and adverse health effects information. Determine levels of exposure that present a significant risk to human health. Identify research needed to fill data gaps. Undergo independent peer review. Make available for public comment. ATSDR’s approach to toxicological profiles was published in the Federal Register on May 11, 1993. Toxicological profiles are developed pursuant to Section 104(i)(3) and (5) of CERCLA for hazardous substances found at DOE waste sites. CERCLA directs ATSDR to develop profiles on substances most commonly found at NPL sites that pose a significant potential threat to human health, as determined by ATSDR and EPA. Section 104(i)(5) of CERCLA, as amended, directs ATSDR (in consultation with EPA) to assess whether adequate information on the health effects of a profiled substance is available. CERCLA directs ATSDR, in conjunction with EPA, to prepare a list, in order of priority, of at least 100 hazardous substances that are most commonly found at facilities on the NPL and, in their sole discretion, are determined to pose the most significant potential threats to human health (52 FR 12866, April 17, 1987). The “Priority List of Hazardous Substances at Department of Energy National Priorities List Sites and Support Document” was released as final in November 1996 (61 FR 38451, July 24, 1996). REFERENCES ATSDR (Agency for Toxic Substances and Disease Registry). 1995. Hanford 1100-Area (US DOE), Richland, Benton County, Washington. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. ATSDR (Agency for Toxic Substances and Disease Registry). 1997a. Hanford 300-Area (DOE), Richland, Benton County, Washington. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. ATSDR (Agency for Toxic Substances and Disease Registry). 1997b. Hanford 200-Area (DOE), Richland, Benton County, Washington. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. ATSDR (Agency for Toxic Substances and Disease Registry). 1999. Toxicological Profile for Ionizing Radiation. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. ATSDR (Agency for Toxic Substances and Disease Registry). 2004a. Y-12 Uranium Releases: U.S. Department of Energy Oak Ridge Reservation Oak Ridge, Anderson County, Tennessee. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.

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Review of the Worker and Public Health Activities Program Administered by the Department of Energy and the Department of Health and Human Services ATSDR (Agency for Toxic Substances and Disease Registry). 2004b. Toxicological Profile for Cesium. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. ATSDR (Agency for Toxic Substances and Disease Registry). 2005a. Public Health Assessment for Los Alamos National Laboratory (USDOE Public Comment version April 26, 2005). Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. ATSDR (Agency for Toxic Substances and Disease Registry). 2005b. TSCA Incinerator: U.S. Department of Energy Oak Ridge Reservation Oak Ridge, Anderson County, Tennessee. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service. ATSDR (Agency for Toxic Substances and Disease Registry). 2006. ATSDR response to committee questions. To the Committee to Review the Worker and Public Health Activities Program, Atlanta, GA, February 10. Cardis, E., M. Vrijheid, M. Blettner, E. Gilbert, M. Hakama, C. Hill, G. Howe, J. Kaldor, C.R. Muirhead, M. Schubauer-Berigan, and T. Yoshimura. 2005. Risk of cancer after low doses of ionising radiation: retrospective cohort study in 15 countries. Br Med J 331(7508):77-80. Darby. S., D. Hill, A. Auvinen, J.M. Barros-Dios, H. Baysson, F. Bochicchio, H. Deo, R. Falk, F. Forastiere, M. Hakama, I. Heid, L. Kreienbrock, M. Kreuzer, F. Lagarde, I. Makelainen, C. Muirhead, W. Oberaigner, G. Pershagen, A. Ruano-Ravina, E. Ruosteenoja, A.S. Rosario, M. Tirmarche, L. Tomasek, E. Whitley, H.E. Wichmann, and R. Doll. 2005. Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies. Brit Med J 330(7485):223. Field, R.W., D.J. Steck, B.J. Smith, C.P. Brus, E.L. Fisher, J.S. Neuberger, C.E. Platz, R.A. Robinson, R.F. Woolson, C.F. Lynch. 2000. Residential radon gas exposure and lung cancer: the Iowa Radon Lung Cancer Study. Amer J Epi 151(11):1091-1102. Krewski, D., J.H. Lubin, J.M. Zielinski, M. Alavanja, V.S. Catalan, R.W. Field, J.B. Klotz, E.G. Letourneau, C.F. Lynch, J.I. Lyon, D.P. Sandler, J.B. Schoenberg, D.J. Steck, J.A. Stolwijk, C. Weinberg, and H.B. Wilcox. 2005. Residential radon and risk of lung cancer: a combined analysis of 7 North American case-control studies. Epidemiology 16(2):137-145. Krewski, D., J.H. Lubin, J.M. Zielinski, M. Alavanja, V.S. Catalan, R.W. Field, J.B. Klotz, E.G. Letourneau, C.F. Lynch, J.L. Lyon, D.P. Sandler, J.B. Schoenberg, D.J. Steck, J.A. Stolwijk, C. Weinberg, and H.B. Wilcox. 2006. A combined analysis of North American case-control studies of residential radon and lung cancer. J Toxicol Environ Health A 69(7):533-597. NCRP (National Council on Radiation Protection and Measurements). 2001. Evaluation of the Linear-Nonthreshold Dose-Response Model for Ionizing Radiation, NCRP Report No. 136. Bethesda, MD. NRC (National Research Council). 1990. Health Effects of Exposure to Low Levels of Ionzing Radiation (BEIR V). Washington, DC: National Academy Press. NRC (National Research Council). 1999. Health Risks of Radon (BEIR VI Report). Washington, DC: National Academy Press. NRC (National Research Council). 2006. Health Risks from Exposure to Low Levels of Ionizing Radiation. BEIR VII Phase 2. Washington, DC: National Academy Press. Tatham, L.M., F.J. Bove, W.E. Kaye, and R.F. Spengler. 2002. Population exposures to I-131 releases from Hanford Nuclear Reservation and preterm birth, infant mortality, and fetal deaths. Int J Hyg Environ Health 205:41-48.