PUBLIC HEALTH ASSESSMENT

WHITE OAK CREEK RADIONUCLIDE RELEASES
OAK RIDGE RESERVATION (US DOE)
OAK RIDGE, ROANE COUNTY, TENNESSEE

IV. PUBLIC HEALTH IMPLICATIONS

IV.A. Introduction

When evaluating the public health impact associated with exposures to hazardous substances, CERCLA, as amended by SARA §104 [i][6][f], requires that ATSDR consider 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 could be associated with the observed levels of exposure.

To evaluate health effects from radiation doses received by individuals exposed to radionuclides released into the Clinch River from White Oak Creek, ATSDR used a "weight-of-dose approach." The weight-of-dose approach involves conducting a critical review of available radiological, medical, and epidemiologic information to ascertain levels of significant human exposure, and then comparing the estimated radiation doses that individuals might have encountered at the Clinch River and LWBR to situations that have been associated with disease and injury. This approach is used to determine whether or not harmful health effects might be possible and observable, and to determine if the doses require a public health action to limit, eliminate, or further study any potential harmful exposures.

The exposure pathways analysis in Section III of this public health assessment indicates that radioactive materials were released from X-10 via White Oak Creek. These radioactive contaminants have migrated off site to the Clinch River and the Lower Watts Bar Reservoir (LWBR), where people have or could come in contact with these contaminants. In this section, ATSDR assesses the health implications of past, current, and future exposures to radioactive contaminants released from White Oak Creek for people who used or lived—or currently use or live—near the Clinch River and LWBR. In assessing exposure, ATSDR evaluated radiation doses presented in the Task 4 report or derived radiation doses using available environmental data. When calculating doses, ATSDR made conservative assumptions about the frequency, duration, and magnitude of radiation exposures. These conservative estimates allow ATSDR to evaluate the likelihood, if any, that exposure to radionuclides is associated with adverse health effects. Because cancer is the most recognized adverse health outcome resulting from radiation exposure (though studies are beginning to show cardiovascular effects in atomic bomb survivors), ATSDR will discuss this disease in the public health implications section.

The public health implications of past exposures at the Clinch River and current exposures associated with the Clinch River and the LWBR are presented in Table 22 and Table 23, respectively, and in the discussion that follows.

Table 22. Past Radiation Doses for the Area Along the Clinch River (1944–1991)

Organ	Dose Type^*	Estimated Dose^†	Comparison Value	Is the Estimated Dose Above or Below the Comparison Value?	Conclusion
Whole body	Annual	4 mrem	100 mrem/year ATSDR MRL, ICRP, NCRP, and NRC^‡	Below (25 times less)	The radiation doses received by people in the past are not likely to cause adverse health effects. Past releases of radioactive material from White Oak Creek are not a public health hazard for people who used or lived near the Clinch River and LWBR.
Whole body	Committed effective dose or lifetime	278 mrem	5,000 mrem^§	Below (18 times less)
Bone surface	Committed equivalent dose or lifetime	Less than 1,600 mrem	390,000–620,000 mrem^¶	Below (243 times less)
Lower large intestine	Committed equivalent dose or lifetime	Less than 1,200 mrem	5,000 mrem^§	Below (4 times less)
Red bone marrow	Committed equivalent dose or lifetime	Less than 1,200 mrem	390,000–620,000 mrem^¶	Below (325 times less)
Breast	Committed equivalent dose or lifetime	Less than 500 mrem	10,000 mrem**	Below (20 times less)
Skin	Committed equivalent dose or lifetime	Less than 700 mrem	9,000 mrem^††	Below (12 times less)

^* Annual dose considers a 1-year exposure. Committed effective doses and committed equivalent doses consider a 70-year exposure duration.
^† The estimated doses were taken from Table 11. Please see the discussion related to Table 11 for an explanation on the derivations of the past radiation doses.
^‡ ATSDR's MRL for ionizing radiation is based on noncancer health effects only; it is not based on a consideration of cancer effects. A MRL is an estimate of daily human exposure to a substance that is likely, during a specified duration of exposure, to be without noncarcinogenic health effects (ATSDR 1999b). For more information on MRLs, please refer to http://www.atsdr.cdc.gov/mrls.html. The ICRP, NCRP, and NRC recommended value of 100 mrem/year for the public considers both noncancer and cancer health effects (Health Physics Society 2003; ICRP 1991; Nuclear Energy Institute 2003).
^§ Based on studies of atomic bomb survivors (National Research Council 1988).
^¶ A review of human radium dial workers suggests that a threshold for bone cancers induced by radium should be between 390,000 and 620,000 mrem (Rowland 1994).
^** Based on studies of atomic bomb survivors (Schull 1995).
^†† Based on studies of patients irradiated for the treatment of ringworm (National Research Council 1990).

Table 23. Current Radiation Doses for the Lower Watts Bar Reservoir and Clinch River

Area and Time Frame	Organ	Dose Type^*	Estimated Dose^†	Comparison Value	Is the Estimated Dose Above or Below the Comparison Value?	Conclusion
Lower Watts Bar Reservoir (1988–2003)	Whole body	Annual	Less than 30 mrem/year	100 mrem/year ATSDR MRL, ICRP, NCRP, and NRC^‡	Below (3 times less)	The current radiation doses received by people are not likely to cause adverse health effects. Current releases of radioactive material from White Oak Creek are not a public health hazard for people who currently use or live near the Clinch River and LWBR.^‡‡
Lower Watts Bar Reservoir (1988–2003)	Whole body	Committed effective dose or lifetime	Less than 1,900 mrem	5,000 mrem^§	Below (2.5 times less)
Clinch River (1989–2003)	Whole body	Annual	Less than 3.4 mrem/year	100 mrem/year^‡	Below (29 times less)
	Whole body	Committed effective dose or lifetime	Less than 236 mrem	5,000 mrem^§	Below (21 times less)
	Bone	Committed equivalent dose or lifetime	Less than 218 mrem	390,000–620,000 mrem^¶	Below (1,788 times less)
	Lower large intestine	Committed equivalent dose or lifetime	Less than 270 mrem	5,000 mrem^§	Below (18 times less)
	Skin	Committed equivalent dose or lifetime	Less than 6 mrem	9,000 mrem^††	Below (1,500 times less)

^* Annual dose considers a 1-year exposure. Committed effective doses and committed equivalent doses consider a 70-year exposure duration for the LWBR and an exposure to age 70 for the Clinch River.
^† The annual and committed doses are based on all exposure pathways combined. To derive the committed effective dose and the committed equivalent dose, the dose for a pathway was adjusted for a 70-year exposure for the LWBR and to age 70 for the Clinch River.
^‡ ATSDR's MRL for ionizing radiation is based on noncancer health effects only; it is not based on a consideration of cancer effects. A MRL is an estimate of daily human exposure to a substance that, during a specified duration of exposure, is likely to be without noncarcinogenic health effects (ATSDR 1999b). For more information on MRLs, please refer to http://www.atsdr.cdc.gov/mrls.html. The ICRP, NCRP, and NRC recommended value of 100 mrem/year for the public considers both noncancer and cancer health effects (Health Physics Society 2003; ICRP 1991; Nuclear Energy Institute 2003).
^§ Based on studies of atomic bomb survivors (National Research Council 1988).
^¶ A review of human radium dial workers suggests that a threshold for radium-induced bone cancers is between 390,000 and 620,000 mrem (Rowland 1994).
^†† Based on studies of patients irradiated for the treatment of ringworm (National Research Council 1990).
^‡‡ ATSDR assessed the estimated current doses in its evaluation of future exposures. See the discussion of future exposures in Section IV.C.

IV.B. Past Radiation Exposure (1944–1991)

ATSDR determined that levels of radioactive contaminants from X-10 that entered the Clinch River via White Oak Creek are not a public health hazard for individuals who, in the past, used or lived near the Clinch River. Past exposure to these radioactive contaminants is not expected to cause adverse health effects.

For past exposures, which for the purposes of this PHA occurred between 1944 and 1991, ATSDR evaluated the health implications of the radiation dose estimates presented in Task 4 of the TDOH's Reports of the Oak Ridge Dose Reconstruction, Radionuclide Releases to the Clinch River from White Oak Creek on the Oak Ridge Reservation—an Assessment of Historical Quantities Released, Off-Site Radiation Doses, and Health Risks (referred to as the "Task 4 report"). As discussed in Section III, ATSDR evaluated the 50^th percentile of the uncertainty distribution for doses reported by the Task 4 team. The doses considered past exposures (over a maximum 48-year exposure period) to radionuclides (Cs 137, Ru 106, Sr 90, Co 60, I 131, Ce 144, Zr 95, and Nb 95) via consumption of fish, meat, milk, and water, and external radiation from walking on shoreline sediment (see Table 11) (see Appendix E). ATSDR focused its evaluation on three locations: Jones Island (CRM 20.5), the K-25/Grassy Creek area (CRM 14), and the confluence of the Clinch River with the Tennessee River (CRM 0) near the city of Kingston. ATSDR then used the organ-specific doses derived by the Task 4 team to estimate both the whole-body dose (annual and committed effective dose over 70 years) and total lifetime organ doses for the bone, lower large intestine, red bone marrow, skin, and female breast.

Table 22 presents ATSDR's estimated whole-body dose (annual dose and committed effective dose over 70 years) and the committed equivalent dose to organs (bone, lower large intestine, red bone marrow, breast, and skin) for past exposures along the Clinch River. An individual exposed to the primary radionuclides in Clinch River water, fish, shoreline sediment, meat, and milk was expected to receive a committed effective dose to the whole body of less than 300 mrem over 70 years and an annual whole-body dose from combining the organ doses of 4 mrem/year. This whole-body dose is well below (18 times less than) ATSDR's radiogenic comparison value of 5,000 mrem over 70 years and the annual whole-body dose is well below (25 times less than) ATSDR's radiogenic minimal risk level (MRL) of 100 mrem/year, which is also the maximum dose constraint for members of the public as recommended by the International Commission on Radiological Protection (ICRP), the U.S. Nuclear Regulatory Commission (NRC), and the National Council on Radiation Protection and Measurements (NCRP). ATSDR also evaluated potential exposures to radionuclides in drinking water (from the K-25 intake) for residents who lived in the Happy Valley settlement camp between 1944 and 1950. ATSDR's estimates suggest that residents of the camp would have received an annual dose of 14 mrem to the whole body, which is at least 7 times less than the ATSDR radiogenic MRL of 100 mrem/year and the ICRP, NRC, and NCRP recommended maximum dose for the public of 100 mrem/year. ATSDR's evaluation of radiological, epidemiological, and medical literature shows that the estimated whole-body radiation doses were well below levels likely to cause observable or detectable health effects.

ATSDR derived the radiogenic comparison value of 5,000 mrem over 70 years after reviewing the peer-reviewed literature and other documents developed to review the health effects of ionizing radiation. Doses below this value are not expected to result in observable health effects. ATSDR's MRL for ionizing radiation of 100 mrem/year is based on noncancer health effects only; it is not based on a consideration of cancer effects. MRLs are estimates of daily human exposures to substances unlikely to result in noncancer effects over a specified duration (ATSDR 1999b). The ICRP, NRC, and NCRP maximum dose constraint for the public of 100 mrem/year considers both noncancer and cancer health effects (Health Physics Society 2003; ICRP 1991; Nuclear Energy Institute 2003).

The doses from past exposure to radionuclides in and along the Clinch River varied by the critical organ. ATSDR's further evaluation of the organ doses is in the discussion that follows.

The bone received the highest estimated total committed equivalent dose over a lifetime (70 years) of exposure to the primary radionuclides along the Clinch River. ATSDR's estimates, however, suggest that the dose to the bone was less than 1,600 mrem over 70 years—at least 243 times lower than the doses of 390,000 to 620,000 mrem shown to cause bone cancers in radium dial workers. Eating many fish meals from the Jones Island area resulted in the highest estimated organ dose to the bone (810 mrem) (see Table 11). Doses to the bone were much lower for people who ate fewer fish or fished further downstream and for all other pathways. Strontium most likely contributed to the higher levels in the bone because it seeks out and accumulates in bone.

Radiation effects on individual organs have not been studied extensively. Most of the available studies on the effects of radiation involve exposures associated with luminous dial painting, the atomic bombing of Japan, medical treatments, and uranium mining. ATSDR's comparison value for the dose to the bone comes from studies that evaluated exposures of radium dial painters to levels of radium known to cause adverse health effects following acute intakes of radium. Workers in these studies were exposed to larger doses and for longer periods of time than exposures associated with White Oak Creek releases. Bone cancers induced by radium exposure were evident in dial workers at doses ranging between 390,000 and 620,000 mrem (Rowland 1994). More recent studies have included workers at nuclear plants and other nuclear industries. For example, studies of nuclear workers at the Mayak facility in Russia suggest that chronic radiation exposure resulting in "chronic radiation syndrome" is associated with cumulative exposures to radiation above 100,000 mrem (USDOE, Office of International Health Programs 2001).¹⁵ In 1999, the Airlie Conference concluded that 10,000 mrem was the lowest dose at which a statistically significant radiation risk has been shown, and that the effects of low-level radiation below 100 mrem/year above background are currently indistinguishable from those of everyday natural health hazards (Mossman et al. 2000).¹⁶ The doses received by individuals in these studies are in substantial excess of the estimated doses from past exposures to White Oak Creek radionuclide releases.

The committed equivalent dose to the lower large intestine was less than 1,200 mrem over 70 years. Exposure from eating fish, from drinking water, and from walking along the shoreline (external exposures) resulted in the highest doses to the lower large intestine. This estimated dose, however, is 4 times lower than ATSDR's radiogenic comparison value of 5,000 mrem over 70 years.

The committed equivalent dose to the red bone marrow was less than 1,200 mrem over 70 years. Exposure from eating fish, drinking Clinch River water, and walking along the shoreline (external exposures) resulted in the highest doses to the red bone marrow. The highest committed equivalent dose, however, is more than 325 times lower than the lowest doses between 390,000 and 620,000 mrem, which is where bone cancers were first observed in radium dial workers with measured amounts of radium in their bodies (Rowland 1994). ATSDR's estimated committed equivalent dose to the red bone marrow for past exposure is also below the levels that epidemiological studies can detect, and below 25,000 mrem, which is the level generally related to blood disorders associated with acute exposures. Doses on the order of 25,000 mrem are believed to affect the formation of blood cells and may induce leukemia. Studies in the atomic bomb survivors indicated that leukemia was observed with acute doses as low as 50,000 millirads (assumed 50,000 mrem), with most of the leukemia occurring within the first 20 years following the bombings (Radiation Effects Research Foundation 2003).

The committed equivalent dose to the breast in females was less than 500 mrem over a 70-year lifetime. Exposure to radionuclides from eating fish and walking on shoreline sediment contributed the highest doses to the breast. For comparison, the committed equivalent dose is 20 times less than doses shown to cause effects in atomic bomb survivors (Schull 1995).

The committed equivalent dose to the skin over a 70-year lifetime of exposure to external radiation was less than 700 mrem. Organ doses to the skin from eating fish and walking along the shoreline exceeded dose estimates for all other pathways. Even so, the committed equivalent dose is 12 times below the value of 9,000 mrem, which is based on the Biological Effects of Ionizing Radiation (BEIR) V report of patients irradiated for the treatment of ringworm (National Research Council 1990).

Organ doses for people who ate fish from the Clinch River exceeded dose estimates for all other exposure pathways (drinking water, meat ingestion, milk ingestion, and external radiation) by at least a factor of 6 (see Table 12). Primarily, the organ dose depended on how often people ate fish and the area of the Clinch River where the fish were collected. The highest cumulative organ doses (1944–1991) were for individuals who consumed fish frequently (1 to 2.5 fish meals per week) and caught their fish near Jones Island, close to the mouth of White Oak Creek. For individuals who frequently ate fish caught near Jones Island and received maximum exposure to radionuclides released from White Oak Creek (see Table 11), ATSDR determined that the estimated doses to each organ were well below ATSDR's comparison values and levels associated with the development of disease or cancer.

Organ doses for people walking along the shore and ingesting milk, water, and meat were much lower than the doses received by people consuming fish (see Tables 11 and 12). For an individual with no exposures other than to shoreline contaminants, the bone and skin were the organs that received the greatest dose. The estimated doses to the bone and skin from walking along the shoreline are well below ATSDR's comparison values and levels associated with the development of disease or cancer. Also, individuals exposed to radionuclides in the past from walking along the shoreline or ingesting milk, water, meat, or fish (further downstream from Jones Island) were not expected to develop adverse health effects or cancer.

Lifetime inhabitants of Grassy Creek (CRM 14) who ingested meat, milk, and water received the highest radiation dose to the bone. ATSDR used the tissue weighting factors to convert each organ dose to the corresponding whole-body dose, and summed the values to achieve a whole-body dose less than 20 mrem. ATSDR does not expect these exposures to have resulted in any observable adverse health effects.

All the estimated doses for past exposure to radionuclides in the Clinch River released from White Oak Creek are lower than ATSDR's comparison values and doses reported in radiological and epidemiological studies on the effects of radiation exposure. Therefore, ATSDR does not expect carcinogenic health effects to have occurred from past exposure to radionuclides in the Clinch River.

IV.C. Current and Future Radiation Exposure (1988–Present and Future)

ATSDR determined that current and future exposure to radioactive materials is not a public health hazard for individuals who use or live near the Clinch River and the Lower Watts Bar Reservoir. Radiation doses for individuals who might contact even the highest current concentrations of radionuclides in Lower Watts Bar Reservoir or Clinch River fish, turtles, geese, surface water, and sediment are too low to be a health hazard now or in the future.

IV.C.1. Current Exposure

For current exposures (1988–present), ATSDR estimated radiation doses for conservative hypothetical scenarios that considered likely pathways of exposure for people who use the LWBR and the Clinch River. ATSDR evaluated current users' exposures to LWBR sediment, surface water, and fish (see Tables 13, 14, 15 for the maximum detected concentrations). ATSDR also evaluated current users' exposures to Clinch River biota (fish, turtles, and geese), external radiation (walking on sediment and swimming), and incidental ingestion of surface water (see Table 17 for the radionuclides evaluated and Table 18 for the exposure pathways evaluated). ATSDR's evaluation shows that current exposures to even the highest detected concentrations of radionuclides in the Clinch River or LWBR biota, sediment, and surface water are not likely to cause health effects for current users of these waterways. In addition, ATSDR analyzed drinking water samples collected around the cities of Kingston, Spring City, and Rockwood from 1990 to the present. ATSDR evaluated these samples for radiological content, and determined that all water samples were below the U.S. Environmental Protection Agency's maximum contaminant levels (MCLs), and therefore, ATSDR considers this water safe for consumption and other potable uses now and in the future.

Lower Watts Bar Reservoir (1988–present)

ATSDR's estimated committed effective dose to the whole body for all pathways combined is less than 1,900 mrem over 70 years—2.5 times below ATSDR's radiogenic CV of 5,000 mrem over 70 years. The estimated annual whole-body dose is less than 30 mrem, and below ATSDR's screening comparison value and ICRP's, NCRP's, and NRC's recommended values for the public of 100 mrem/year. Therefore, the estimated exposures for the LWBR are not expected to result in adverse health effects.

Clinch River (1989–present)

ATSDR's estimated committed effective dose to the whole body for all pathways along the Clinch River combined is less than 240 mrem to 70 years of age—more than 20 times below ATSDR's radiogenic CV of 5,000 mrem over 70 years. The estimated annual whole-body dose is less than 3.4 mrem, and nearly 30 times below the dose of 100 mrem per year recommended for the public by ATSDR, ICRP, NCRP, and NRC. Therefore, the estimated exposures for the Clinch River are not expected to result in adverse health effects.

The current radiation doses from exposure to radionuclides along the Clinch River varied by organ as summarized below.

ATSDR estimated that the bone receives the highest total committed equivalent dose over a lifetime (i.e., to age 70) of exposure to the primary radionuclides detected along the Clinch River. The highest committed equivalent doses to the bone were estimated for a 15-year-old adolescent based on a 55-year exposure from ingestion of goose muscle or liver (230 mrem) and fish (114 mrem), which resulted in a committed equivalent dose of 344 mrem over 55 years. ATSDR's estimates indicate that the teenager would receive the highest dose because of the age-weighted dose coefficients associated with accelerated bone growth in this age group. The committed equivalent dose to the bone from all pathways combined was based on exposures for adults occurring over a 50-year period. Estimates suggest that the committed equivalent dose to the bone for adults from all pathways is less than 218 mrem to 70 years of age. This is at least 1,788 times lower than the doses of 390,000 to 620,000 mrem associated with bone cancers in radium dial workers. Much lower doses were associated with ingestion of Clinch River water (2.8 mrem) and external exposures from walking on sediment (13 mrem) and swimming (1.2 mrem) in the study area. Note that the bone dose for swimming at background locations (expressed as the average of all background locations under study) of 5.83 mrem exceeds the dose incurred from swimming in the Clinch River study area.

On the basis of exposures estimated for a 20-year-old adult over 50 years, the committed equivalent dose to the lower large intestine from all pathways combined is less than 270 mrem. This estimated dose is about 18 times lower than ATSDR's radiogenic comparison value of 5,000 mrem over 70 years, which is based on studies of atomic bomb survivors, radiation workers, and radiation workers' children. Exposure to radionuclides from adults eating fish contributed to the highest committed equivalent dose—109 mrem—to the lower large intestine.

The committed equivalent dose to the skin over a 50-year exposure for adults is less than 6 mrem, which is 1,500 times below the value of 9,000 mrem that is based on a review of the BEIR V report of patients irradiated for ringworm treatment (National Research Council 1990). As one would expect from the amount of skin exposure, swimming in the Clinch River resulted in the highest dose to the skin (3.9 mrem) out of all pathways evaluated.

Estimated doses for current exposure to radionuclides in the LWBR and Clinch River released from White Oak Creek in the present are lower than ATSDR's screening comparison values and doses reported in radiological and epidemiological studies on the effects of radiation exposure. ATSDR does not expect these current exposures to result in any adverse health effects.

IV.C.2. Future Exposure

For future exposures (exposures occurring after the "current" time period), ATSDR evaluated current doses and exposures related to releases from White Oak Creek, data on current contaminant levels in the LWBR and the Clinch River, consideration of the possibility that radionuclides could be released to White Oak Creek during remedial activities, engineering controls to prevent off-site releases, and institutional controls that are in place to monitor contaminants in the LWBR and the Clinch River. These institutional controls consist of

prevention of sediment-disturbing activities in the Clinch River and LWBR,
the Department of Energy's (DOE) annual monitoring of Clinch River and LWBR surface water, sediment, and biota,
DOE's monitoring of White Oak Creek releases,
the Tennessee Department of Environment and Conservation's (TDEC) monitoring of public drinking water supplies in Tennessee under the Safe Drinking Water Act for EPA-regulated contaminants, and
TDEC DOE Oversight Division's quarterly radiological monitoring of five public water supplies on the ORR and in its vicinity under the EPA's Environmental Radiation Ambient Monitoring System program.

Lower Watts Bar Reservoir and Clinch River

Because the current radionuclide levels in the Clinch River and LWBR are not expected to result in adverse health effects, because on-site engineering controls are in place to prevent off-site contaminant releases, and because institutional controls reduce and monitor contaminants released from White Oak Creek, ATSDR concludes that future contaminant levels in the Clinch River and LWBR will not increase as a result of White Oak Creek releases. This conclusion is also based on DOE continuing its expected comprehensive system of monitoring (e.g., of remedial activities and contaminant levels in media), maintenance, and institutional and engineering controls. Further, because of remedial actions and preventive measures at X-10, and because of physical movement of sediments from that area and radiological decay, the radionuclide releases from White Oak Creek have decreased over time. The concentrations of radionuclides in the water and along the shoreline have decreased as well. Though a slight potential remains that radionuclides could be released to White Oak Creek due to remedial activities taking place at the ORR, these releases are expected to be minimal, and as noted previously, would be monitored by DOE. Therefore, as current exposures are not expected to result in adverse health effects, ATSDR does not expect adverse health effects to result from future concentrations of radionuclides in the Clinch River or Lower Watts Bar Reservoir fish, geese, turtles, sediment, or surface water.

V. HEALTH OUTCOME DATA EVALUATION

Health outcome data are measures of disease occurrence in a population. Common sources of health outcome data are existing databases (cancer registries, birth defects registries, death certificates) that measure morbidity (disease) or mortality (death). Health outcome data can provide information on the general health status of a community—where, when, and what types of diseases occur and to whom they occur. Public health officials use health outcome data to look for unusual patterns or trends in disease occurrence by comparing disease occurrences in different populations over periods of years. These health outcome data evaluations are descriptive epidemiologic analyses. They are exploratory as they could provide additional information about human health effects and they are useful to help identify the need for public health intervention activities (for example, community health education). That said, however, health outcome data cannot—and are not meant to—establish cause and effect between environmental exposures to hazardous materials and adverse health effects in a community.

ATSDR scientists generally consider health outcome data evaluation when there is a plausible, reasonable expectation of adverse health effects associated with the observed levels of exposure to contaminants. In this public health assessment on X-10 radionuclide releases to the Clinch River and the Lower Watts Bar Reservoir from White Oak Creek, ATSDR scientists determined that people using the Clinch River and the Lower Watts Bar Reservoir for food, water, and recreation were exposed to radionuclides released via White Oak Creek from the 1940s to 2003.

Criteria for Conducting a Health Outcome Data Evaluation

To determine how to use or analyze health outcome data in the public health assessment process, or even whether to use it at all, ATSDR scientists receive input from epidemiologists, toxicologists, environmental scientists, and community involvement specialists. These scientists consider the following criteria, based only on site-specific exposure considerations, to determine whether a health outcome data evaluation should be included in the public health assessment.

Is there at least one current (or past) potential or completed exposure pathway at the site?

Can the time period of exposure be determined?

Can the population that was or is being exposed be quantified?

Are the estimated exposure doses(s) and the duration(s) of exposure sufficient for a plausible, reasonable expectation of health effects?

Are health outcome data available at a geographic level or with enough specificity to be correlated to the exposed population?

Do the validated data sources or databases have information on the specific health outcome(s) or disease(s) of interest—for example, are the outcome(s) or disease(s) likely to occur from exposure to the site contaminants—and are those data accessible?

Using the findings of the exposure evaluation in this public health assessment, ATSDR sufficiently documented completed exposure pathways to radionuclides via the surface water, sediment, and biota pathways from the mid-1940s to 2003 for people using the Clinch River and the Lower Watts Bar Reservoir. In this public health assessment, the documented evidence of off-site exposure to radionuclides indicates that estimates of past and current radiation doses are below doses associated with health effects (see Section IV. Public Health Implications).

The estimated radiation doses for people using the Clinch River and the Lower Watts Bar Reservoir for food, water, and recreation are less than the 1) average U.S. background radiation dose, 2) ATSDR's screening values for ionizing radiation, 3) the NCRP's, ICRP's, and NRC's recommended limits of exposure to the public, and 4) organ-specific doses shown to cause adverse health effects. Therefore, residents using the river and reservoir have not been exposed to harmful levels of radionuclides from White Oak Creek, and they are not currently being exposed to harmful levels of radionuclides released to White Oak Creek from the X-10 site. Because the estimated radiation doses are not expected to cause health effects, no further analysis of health outcome data is appropriate. Analysis of site-related health outcome data is not scientifically reasonable unless the level of estimated exposure is likely to result in an observable number of health effects. And because such an estimate of exposure cannot be made, the requirement to consider analysis of site-related health outcome data on the basis of exposure is complete.

Responding to Community Concerns

Responding to community health concerns is an essential part of ATSDR's overall mission and commitment to public health. Concerns of all community members are important and must be addressed during the public health assessment process. The individual community health concerns addressed in the Community Health Concerns section (Section VI) of this public health assessment are concerns from the ATSDR Community Health Concerns Database that are related to issues associated with radionuclides released from White Oak Creek.

Area residents have also voiced concerns about cancer. Citizens living in the communities surrounding the ORR expressed many concerns to the ORRHES about a perceived increase in cancer in areas surrounding the ORR. A 1993 TDOH survey of eight counties surrounding the ORR indicated that cancer was mentioned as a health problem more than twice as much as any other health problem. The survey also showed that 83% of the surveyed population in the surrounding counties believed it was very important to examine the actual occurrence of disease among residents in the Oak Ridge area.

"Cancer incidence" refers to newly diagnosed cases of cancer that are reported to the Tennessee Cancer Registry.

To address these concerns, ORRHES requested that ATSDR conduct an assessment of health outcome data (cancer incidence) in the eight counties surrounding the ORR. Therefore, ATSDR conducted an assessment of cancer incidence using data already collected by the Tennessee Cancer Registry. This assessment is a descriptive epidemiologic analysis that provides a general picture of the occurrence of cancer in each of the eight counties. The purpose of this evaluation was to provide citizens living in the Oak Ridge Reservation area with information regarding cancer rates in their county compared to the state of Tennessee. The evaluation only examines cancer rates at the population level—not at the individual level. It is not designed to evaluate specific associations between adverse health outcomes and documented human exposures, and it does not—and cannot—establish cause and effect.

The results of the assessment of cancer incidence, released in 2006, indicated both higher and lower rates of certain cancers in some of the counties examined when compared to cancer incidence rates for the state of Tennessee. Most of the cancers in the eight-county area occurred at expected levels, and no consistent pattern of cancer occurrence was identified. The reasons for the increases and decreases of certain cancers are unknown. ATSDR's ORR Assessment of Cancer Incidence is available online at http://www.atsdr.cdc.gov/HAC/oakridge/phact/cancer_oakridge/index.html.

In addition, over the last 20 years, local, state, and federal health agencies have conducted public health activities to address and evaluate public health issues and concerns related to chemical and radioactive substances released from the Oak Ridge Reservation. For more information, please see the Compendium of Public Health Activities at http://www.atsdr.cdc.gov/HAC/oakridge/phact/c_toc.html.

VI. COMMUNITY HEALTH CONCERNS

ATSDR actively gathers comments and other information from those who live or work near the ORR. ATSDR is particularly interested in hearing from area residents, civic leaders, health professionals, and community groups. ATSDR will be addressing these community site-related health concerns in the ORR public health assessments that are related to those concerns.

To improve the documentation and organization of community health concerns at the ORR, ATSDR developed a Community Health Concerns Database specifically designed to compile and track community health concerns related to the site. The database allows ATSDR to record, track, and respond appropriately to all community concerns, and also to document ATSDR's responses to these concerns.

From 2001 to 2005, ATSDR compiled more than 3,000 community health concerns obtained from the ATSDR/ORRHES community health concerns comment sheets, written correspondence, phone calls, newspapers, comments made at public meetings (ORRHES and work group meetings), and surveys conducted by other agencies and organizations. These concerns were organized in a consistent and uniform format and imported into the database.

The community health concerns addressed in this public health assessment are those concerns in the ATSDR Community Health Concerns Database that are related to issues associated with radionuclide releases from White Oak Creek. The following table contains the actual comments and ATSDR's responses. These concerns and responses are sorted by category (e.g., X-10 facility processes and exposure pathway concerns, concerns about radionuclides associated with X-10's releases to White Oak Creek, concerns about contaminants released from the Oak Ridge Reservation, and general concerns related to the Oak Ridge Reservation).

Community Health Concerns From the Oak Ridge Reservation Community Health Concerns Database

	Actual Comment	ATSDR's Response
*X-10 Processes and Exposure Pathways Evaluated*
1	My first thoughts are what are the routes of entry, what are we looking at from the waterway, from the airway, from the soil. Because if you are talking about the water and fisherman and residents you're talking downstream. But if you're talking wind, I don't know where that ends. I would like to hear what are you're thoughts are on what routes are we looking at. That would expand it even further if you look at sports men and the hunting migration.	This public health assessment evaluates the releases of radionuclides from the X-10 facility (now known as the Oak Ridge National Laboratory [ORNL]) into the water in White Oak Creek, and also assesses past, current, and future off-site exposures to these radionuclides in the water for residents living within the White Oak Creek study area (the area along the Clinch River and the Lower Watts Bar Reservoir from the Melton Hill Dam to the Watts Bar Dam [see Figure 11]). This public health assessment evaluates the following key issues and concerns: surface water and sediment (surface and deep channel), and surface water, milk, game animals, fish, turtles, and homegrown vegetables. Please see Section. III.B. Exposure Evaluation of the Clinch River and Lower Watts Bar Reservoir and Figure 20. Possible Exposure Situations Along the Clinch River for more details.
2	How did they/are we looking at the X-10's major processes that may still be delivering an effect? There were cesium releases from the dam in 1985. And a flood in 1964 along with regular releases.	The Tennessee Department of Health's 1999 Reports of the Oak Ridge Dose Reconstruction, Radionuclide Releases to the Clinch River from White Oak Creek on the Oak Ridge Reservation—an Assessment of Historical Quantities Released, Off-Site Radiation Doses, and Health Risks (referred to as the "Task 4 report") focused on historical X-10 radionuclide releases to White Oak Creek dating back to 1944. ATSDR has evaluated the historical data, as well as data that were collected since the dose reconstruction (for example, data from the state of Tennessee, EPA, and DOE). As a result, this public health assessment evaluates the past and current, as well as future, off-site exposures related to radionuclides from X-10. In this public health assessment, ATSDR considers the potential effects from the releases of cesium that occurred in 1956 when severe rains caused a flood that eroded the bottom sediment of White Oak Lake (Blaylock et al. 1993; ChemRisk 1999a). In addition, the Task 4 report estimated the amount of radionuclides that were released to White Oak Dam, and ATSDR considers these releases in its public health assessment (ChemRisk 1999a). See Appendix D for a brief on the Task 4 report. Copies of the Task 4 report are available at the DOE Information Center located at 475 Oak Ridge Turnpike, Oak Ridge, Tennessee (telephone number: 865-241-4780) or through DOE's public-use database at http://cedr.lbl.gov/DR/dror.html .
3	The problems of the buried waste include little documentation on low-level waste, and that the X-10 records on high-level waste were destroyed in 1984. Some were reconstructed, but in general that is not an accurate inventory. That makes more important the good records of the outflows off the reservation.	In general, the records on X-10's earlier operations are not complete. However, a rather accurate account of X-10's major waste generating programs has been created from reviewing available records and by interviewing employees who worked at X-10 throughout most of its operational history. Six activities were determined to be responsible for basically all of X-10's waste production and on-site waste disposal. The six activities were the following (USEPA 1996): Fuel reprocessing Isotope production Waste management Radioisotope applications Reactor developments Multi-program laboratory operations The liquid and solid waste streams that were generated by these activities at X-10 can be described as non-hazardous, chemically hazardous, radioactive, or mixed (for example, consisting of both hazardous chemicals and radioactive substances). Even though X-10 generates various types of waste streams, the majority of its hazardous waste is mixed or radioactive. In addition to X-10's on-site waste production, a large amount of solid, low-level radioactive wastes that were produced at other sites are brought to the X-10 site for disposal. Several remedial activities have been conducted at the X-10 site (USEPA 1996). See Section II.C. Remedial and Regulatory History for more details. In addition, the Tennessee Department of Health evaluated radioactive waste disposal at X-10 dating back to 1944 in its Task 4 report titled Radionuclide Releases to the Clinch River from White Oak Creek on the Oak Ridge Reservation—an Assessment of Historical Quantities Released, Off-Site Radiation Doses, and Health Risks. See Appendix D for a brief on the 1999 Task 4 report. Copies of the Task 4 report are available at the DOE Information Center located at 475 Oak Ridge Turnpike, Oak Ridge, Tennessee (telephone number: 865-241-4780) or through DOE's public-use database at http://cedr.lbl.gov/DR/dror.html .
4	A subcommittee member asked whether, since vegetables and fish are the dominant pathways, people who live downstream are at higher risk.	In 1996, ATSDR conducted a health consultation to evaluate the health implications of current exposure to chemical and radiological contaminants in the Lower Watts Bar Reservoir (LWBR) surface water, sediment, and fish. ATSDR concluded that only PCBs in reservoir fish were of potential public health concern. The current levels of other contaminants in surface water, sediment, and fish were not a public health hazard. See Appendix D for a brief on the 1996 Health Consultation on the Lower Watts Bar Reservoir. ATSDR evaluated radioactive contaminant data for the Clinch River and the LWBR surface water, sediment, and fish, as well as Clinch River vegetables, turtles, and local game animals. The agency's purpose was to determine whether the levels of radionuclides might pose a past, current, or future public health hazard. The evaluation included the following exposure scenarios (depending on the waterway and time period): Incidental ingestion of water during recreational activities Use of river or reservoir water as drinking water Contact with surface sediment Contact with dredged sediment used as topsoil in home gardens Consumption of locally grown milk, meat, or produce Consumption of fish, turtles, or local game animals ATSDR concluded that people who used or who lived near the Clinch River could have contacted these radionuclides in the past by eating fish and meat, by drinking milk and water, and by walking along shoreline sediment. In the past, the highest cumulative organ doses were for people who frequently ate fish (i.e., 1 to 2.5 fish meals per week) caught near Jones Island, close to the mouth of White Oak Creek. For persons who frequently ate fish caught near Jones Island and who received maximum exposure to radionuclides released from White Oak Creek, ATSDR determined that the estimated doses to each organ were well below ATSDR's comparison values and below levels associated with the development of disease or cancer. In addition, past exposure to radionuclides from drinking milk and water, walking along the shoreline, or eating meat and fish further downstream from Jones Island is not a health hazard and is not expected to result in adverse health effects or cancer. Therefore, ATSDR concluded that past exposures to radionuclides in sediment, surface water, and food in the Clinch River pose no apparent public health hazard. ATSDR concluded that currentand future exposures to radionuclides from drinking surface water, contacting surface water and shoreline sediment via recreation, and consuming fish and game is not a health hazard because current exposure to radionuclides in the Clinch River and LWBR would result in radiation doses below levels expected to cause adverse health effects. Thus, current exposure to radionuclides released to the Clinch River and the LWBR via White Oak Creek poses no apparent public health hazard. ATSDR is still evaluating past exposure to mercury and PCBs in the Clinch River and Lower Watts Bar Reservoir, and will address the health implications of past exposure to these contaminants in future public health assessments.
5	My question is about safe gardening. How could you consider safe gardening in a contaminated soil?	The general answer is that it depends on what the soil is contaminated with and how much is contaminated. This public health assessment evaluates exposures to radioactive contaminants released to the Clinch River and the Lower Watts Bar Reservoir via White Oak Creek. In the dose reconstruction of radionuclides released historically, the Task 4 report determined that the radionuclide levels in irrigation water (for homegrown vegetables) were below screening levels and therefore were not considered a hazard to people who ate locally grown vegetables. Given its assessment of both past and current data, ATSDR does not believe that radionuclides in soil within the White Oak Creek study area present a health hazard for people who consume vegetables from their gardens. ATSDR will address this question further when it considers other contaminants in future public health assessments. As a general rule, ATSDR recommends that everyone wash and peel all homegrown fruits, vegetables, and root crops before consumption. For more information on ATSDR's analysis of homegrown vegetables, see Section III.B. Exposure Evaluation of the Clinch River and Lower Watts Bar Reservoirfor more details.
6	Was any analysis done of the game living on the reservation?	The annual DOE monitoring reports include analysis of some of the game that live on the reservation. Also, some of the ecological studies conducted under EPA's Superfund clean up work will include data on game. These DOE monitoring reports are available from the DOE Information Center located at 475 Oak Ridge Turnpike, Oak Ridge, Tennessee. You can obtain documents from the Information Center at http://www.oakridge.doe.gov/info_cntr/index.html or by calling 865-241-4780. This public health assessment evaluates the past consumption of fish and the current (1988–2003) consumption of fish, geese, and turtles that might have lived on the reservation property. Please see Section III.B. Exposure Evaluation of the Clinch River and the Lower Watts Bar Reservoir for more information.
7	People, actually, some of you might kind of take this lightly, but a lot of people in Oak Ridge feel this same way, a lot of people in Oak Ridge don't drink Oak Ridge water. They buy water. They don't drink Oak Ridge water.	Oak Ridge is supplied with public water from a water treatment plant that draws surface water from Melton Hill Lake. The intake at the lake is located approximately 1 mile upstream of the ORR. Until May 2000, DOE owned and operated the water treatment plant at its Y-12 facility and sold drinking water to the city of Oak Ridge for distribution to residents and businesses. The city of Oak Ridge now owns and operates the water distribution system (City of Oak Ridge 2002). Under the Safe Drinking Water Act, EPA sets health-based standards for hundreds of substances in drinking water and specifies treatments for providing safe drinking water (USEPA 1999a). The public water supply for Oak Ridge is continually monitored for these regulated substances. The Tennessee Department of Environment and Conservation (TDEC) receives a copy of the monitoring report to ensure that people are receiving clean drinking water. More information about the quality of the Oak Ridge public water supply system can be found at: http://www.cortn.org/PW-html/CCR2004.pdf (City of Oak Ridge 2002.) To ask specific questions related to your drinking water, please call TDEC's Environmental Assistance Center in Knoxville, Tennessee at 865-594-6035. To find additional information related to your water supply or other water supplies in the area, please call EPA's Safe Drinking Water Hotline at 800-426-4791 or visit EPA's Safe Drinking Water Web site at http://www.epa.gov/safewater . You can also look up monitoring results for the Oak Ridge or other public water supplies by visiting EPA's Safe Drinking Water Information System at http://www.epa.gov/enviro/html/sdwis/sdwis_query.html .
8	Do agencies do some of their own sampling even when it has already been done before? The Ten Mile area gets water from a company in Spring City and this company has another company of choice test it. The State has never tested it independently and did not follow-up on water testing. Could ATSDR take a sample?	If ATSDR believed that the water at Spring City was a public health issue, then it would recommend that sampling be conducted. However, based on this PHA's findings and ongoing monitoring programs, additional sampling is not necessary. Under the Safe Drinking Water Act, EPA sets health-based standards for hundreds of substances in drinking water and specifies treatments for providing safe drinking water (USEPA 1999a). The public water supplies for Kingston, Spring City, and Rockwood—systems in the White Oak Creek public health assessment study area that draw their water from the Tennessee River system—are continually monitored for these regulated substances. According to EPA's Safe Drinking Water Information System (SDWIS), the Kingston, Spring City, and Rockwood public water supply systems have not had any significant violations (USEPA 2004b). To look up information for these water supplies or other supplies in the area, go to EPA's SDWIS Web site at http://www.epa.gov/enviro/html/sdwis/sdwis_query.html . In 1996, the Tennessee Department of Environment and Conservation's (TDEC) DOE Oversight Division began participating in EPA's Environmental Radiation Ambient Monitoring System (ERAMS). Under this program, TDEC has conducted filter backwash sludge sampling at Spring City because contaminants from the ORR could potentially move downstream into community drinking water supplies. Also since 1996, EPA has analyzed samples from five public water suppliers located on and near the ORR through its ERAMS drinking water program. On a quarterly basis, TDEC takes finished drinking water samples from these locations and EPA analyzes the samples for radionuclides. The public water suppliers are as follows: Kingston Water Treatment Plant (TRM 568.4), DOE Water Treatment Plant at K-25 (CRM 14.5), West Knox Utility (CRM 36.6), DOE Water Treatment Plant at Y-12 (CRM 41.6), and Anderson County Utility District (CRM 52.5) (TDEC 2003b). In addition, the Tennessee Valley Authority (TVA) conducts sampling of radionuclides in fish tissues, and also analyzes the PCBs, pesticides, and metals in sediments from the river mile at Spring City.
9	When you're thinking of Bradbury (TN), that's basically going west of Exit 10. So the impact is basically southwest of the fact—to me it looks that people along the interstate, that area, would have been most susceptible to iodine than Bradbury. But Bradbury would be the most susceptible to some of the stuff dumped in White Oak Creek.	This public health assessment evaluates the X-10 releases of radionuclides into the water in White Oak Creek, which flows into the Clinch River and the Lower Watts Bar Reservoir. This assessment evaluates past, current, and future exposure to radionuclide releases for people who use or live along the Clinch River and the Lower Watts Bar Reservoir (the area along the Clinch River from the Melton Hill Dam to the Watts Bar Dam [see the study area in Figure 11]). Bradbury and I-40 areas are in the study area. This document does not address the X-10 releases of iodine 131 into the air. ATSDR will evaluate the release of iodine 131 into the air in a future public health assessment.
10	Two community members noted that there was a barrier at White Oak Creek, but that people still fished there. The community members continued that the barrier was simply a cable that went across with a sign that said not to enter the area. They said that people would lift this up, go under the cable, and fish at the creek.	White Oak Creek is located on the Oak Ridge Reservation. Because White Oak Creek is on the ORR, access to the creek is restricted and controlled by DOE (ChemRisk 1999a). DOE has a cable barrier that runs across White Oak Creek to prevent trespassers from entering the creek for fishing and other prohibited activities. Also, DOE has posted warning signs at the creek so that people will not enter the area (EEWG [former PHAWG] meeting minutes, May 5, 2003). Therefore, people who fish or enter White Oak Creek for other purposes are trespassing on DOE property.
11	She wondered if there are any substances in the drinking water.	Kingston maintains public water supplies in the vicinity of the Oak Ridge Reservation (see Figure 13). The Kingston water supply has two water intakes, but only one of the intakes—located upstream on the Tennessee River in Watts Bar Lake at Tennessee River Mile (TRM) 568.4—would potentially be impacted by ORR contaminants (Hutson and Morris 1992; G. Mize, Tennessee Department of Environment and Conservation, Drinking Water Program, personal communication re: Kingston public water supply, 2004). Spring City obtains its water from an intake on the Piney River branch of Watts Bar Lake (Hutson and Morris 1992). The city of Rockwood receives its water from an intake on the King Creek branch of Watts Bar Lake, located at TRM 552.5 (TDEC 2001, 2006b; TVA 1991). Under the Safe Drinking Water Act, the EPA has set health-based standards for substances in drinking water and specified treatments for providing safe drinking water since 1974 (USEPA 1999a). In 1977, EPA gave the state of Tennessee authority to operate its own Public Water System Supervision Program under the Tennessee Safe Drinking Water Act. Through this program, TDEC's Division of Water Supply regulates drinking water at all public water systems. As a requirement of this program, all public water systems in Tennessee individually monitor their water supply for EPA-regulated contaminants and report their monitoring results to TDEC. The public water supplies for Kingston, Spring City, Rockwood, and other supplies in Tennessee are monitored for substances that include 15 inorganic contaminants, 51 synthetic and volatile organic contaminants, and 4 radionuclides (USEPA 2004a). EPA's monitoring schedules for each contaminant is available at http://www.epa.gov/safewater/pws/pdfs/qrg_smonitoringframework.pdf (USEPA 2004a). On a quarterly basis, TDEC submits the individual water supply data to EPA's Safe Drinking Water Information System (SDWIS) (TDEC 2003c). According to EPA's SDWIS, the Kingston, Spring City, and Rockwood public water supply systems have not had any significant violations (USEPA 2004b). To look up information related to these and other public water supplies, go to EPA's Local Drinking Water Information Web Site at http://www.epa.gov/safewater/dwinfo.htm . In addition, in 1996 TDEC's DOE Oversight Division started to participate in EPA's Environmental Radiation Ambient Monitoring System (ERAMS). As part of the Oak Ridge ERAMS program, TDEC collects samples from five facilities on the ORR and in its vicinity. Under the Oak Ridge ERAMS, TDEC collects finished drinking water samples from the Kingston Water Treatment Plant on a quarterly basis and then submits the samples to EPA for radiological analyses. The schedule and contaminants sampled at the Kingston Water Treatment Plant are presented in Section II.F.3. Also see the TDEC–DOE Oversight Division's annual report to the public at http://www.state.tn.us/environment/doeo/active.shtml for a summary of radiological drinking water sampling results. TDEC has also conducted filter backwash sludge sampling at Spring City because radioactive contaminants from the ORR could potentially move downstream into community drinking water supplies. TDEC analyzed Spring City samples for gross alpha, gross beta, and gross gamma emissions (TDEC 2002, 2003a, 2003b). To ask specific questions related to your drinking water, please call TDEC's Environmental Assistance Center in Knoxville, Tennessee at 865-594-6035 or call EPA's Safe Drinking Water Hotline at 800-426-4791. More details are also available at EPA's Safe Drinking Water Web site at http://www.epa.gov/safewater/ .
*Radionuclides Associated with X-10's Releases to White Oak Creek*
12	A subcommittee member asked about known health effects of niobium, sheet metal form.	Niobium has been used on the Oak Ridge Reservation at both the X-10 and Y-12 plants. In Phase I of the Oak Ridge Health Studies (Dose Reconstruction Feasibility Study), the Tennessee Department of Health investigated niobium from the Oak Ridge Reservation and determined that it was not a high priority contaminant. In, however, the Reports of the Oak Ridge Dose Reconstruction, Radionuclide Releases to the Clinch River from White Oak Creek on the Oak Ridge Reservation—an Assessment of Historical Quantities Released, Off-Site Radiation Doses, and Health Risks (referred to as the "Task 4 report"), TDOH reevaluated niobium 95 releases into White Oak Creek and the radiation dose from niobium 95 was included in the evaluation of external exposure from shoreline sediments. In addition, the state reevaluated niobium from Y-12 in the Task 7 Report—Screening-level Evaluation of Additional Potential Materials of Concern. Through its assessment, the state determined that quantities of niobium from Y-12 were not large enough to present health risks to off-site populations (ATSDR et al. 2000; ChemRisk 1999b). Data on the toxicological effects of niobium are very limited, and EPA has not established regulatory limits for chronic exposure to niobium (ChemRisk 1999b). Most people rarely encounter niobium compounds. Unless known otherwise, all niobium compounds should be regarded as highly toxic in the laboratory. The metal dust causes eye and skin irritation, and is likely to represent a fire hazard. See Appendix D for briefs on the 1993 Phase I Dose Reconstruction Feasibility Study, the 1999 Task 4 report, and the 1999 Task 7 report. Copies of these three reports are available at the DOE Information Center located at 475 Oak Ridge Turnpike, Oak Ridge, Tennessee (telephone number: 865-241-4780) or through DOE's public-use database at http://cedr.lbl.gov/DR/dror.html .
13	Does cesium stay in the muscle?	Cesium can enter the body through ingestion, inhalation, or injury to the skin. Once cesium enters the body, it is dispersed throughout the body's soft tissues. Slightly larger concentrations of cesium are found in muscle compared with amounts of cesium found in bone and fat. Compared with some of the other radionuclides, cesium remains in the body for a fairly short period of time (USEPA 2003a). Cesium does not stay in the muscle or other tissues. Cesium has a physical half-life of about 30 years and a biological half-life of 70 days. Therefore, the cesium is removed from the body through urine in about 70 days (EEWG [former PHAWG] meeting minutes from December 10, 2001; USEPA 2003a).
14	A community member thought that over 2,000 curies (Ci) were released in one year (1956) over White Oak Dam, but this was a short half-life. He thought that it was two weeks for ruthenium 106. The community member thought that ruthenium went to rhodium, which had the largest beta of any radionuclide.	Ruthenium (Ru) 106 is a fission product with a radioactive half-life of approximately 368 days. Ru 106 decays, releasing a beta particle with energy of 0.039 million electron volts (MeV). This means that Ru 106 is a very weak emitter; however, its decay product rhodium (Rh) 106 is a very strong beta particle emitter. Rh 106 has a radioactive half-life of about 30 seconds and the maximum beta particle energy emission is 3.5 MeV. Rh 106 also emits several gamma rays of varying energy. When Ru 106 is taken into the body, the dose methodology and the dose coefficients used take into account the production of rhodium by the radioactive decay of the ruthenium. However, the dose delivered by the rhodium is not considered because its half-life of 30 seconds is too short to have an impact. In fact, neither the ICRP nor the EPA publish dose coefficients for Rh 106.
15	Back in the 1950s and 1960s when they were doing a lot of testing, strontium was a big worry. I'd never heard of I 131. Everyone was concerned then about health effects from strontium. Now all this talk about I 131. All of this was from same fallout (I 131 and strontium). Strontium pathway is basically the same as iodine.	The Task 4 report evaluated the estimated amount of radioactivity that was released from X-10 into White Oak Creek. During its evaluation, the state determined that specific radionuclides required further investigation; strontium 90 and iodine 131 were both included in this group. In this PHA, ATSDR evaluated past and current exposure to strontium contamination released from White Oak Creek, and determined that the levels of strontium in the water, sediment, vegetables, fish, and game were too low to be of public health concern (ChemRisk 1999a). See Section III. Evaluation of Environmental Contamination and Potential Exposure Pathways in this PHA for ATSDR's analysis of past and present exposures to strontium. ATSDR will address historical exposures to iodine 131 released into the air from X-10 in a future PHA. Inhalation, drinking water, and food consumption are the pathways for both iodine and strontium. However, the primary health effects differ between these two radionuclides. Strontium 90 affects bone marrow and bone surfaces; its 29-year radioactive half-life and 30-year biological half-life make strontium one of the more hazardous contaminants associated with radioactive fallout. The primary health concerns for strontium include bone tumors and tumors in the blood cell forming organs. Whereas iodine 131 is deposited into the thyroid, and consequently, the primary health concern for iodine 131 is thyroid tumors. Traditionally, the primary exposure pathway to iodine 131 has been drinking milk from cows that consumed contaminated crops. Consumption of fruits and vegetables, and also inhalation, are other exposure pathways for iodine 131 (INEEL 2001a, 2001b). ATSDR will provide additional information on iodine from X-10 in a future PHA on iodine 131.
*Evaluation of Contaminants Released from the Oak Ridge Reservation*
16	The board (ORRHES) should familiarize itself with the off-site contamination that has gone on down river and downstream. There are 6 initial contaminants of concern (which include iodine 131, mercury, uranium, radionuclides in White Oak Creek, polychlorinated biphenyls, fluorine/fluoride), although there may be others. Why weren't the Oak Ridge signature contaminants of nickel, strontium, cesium, and chromium, which are in residents' bodies, included in the Phase I evaluation, and why was it not peer reviewed?	At the March 2001, June 2001, December 2001, and February 2002 Oak Ridge Reservation Health Effects Subcommittee (ORRHES) meetings, and at the Exposure Evaluation Work Group (formerly known as the Public Health Assessment Work Group [PHAWG]) meetings in 2001 and 2002, ATSDR presented and discussed in detail its screening process for evaluating past exposures (1944–1990) and determining contaminants of concern that warrant further evaluation. This comprehensive screening analysis included an evaluation of releases of hazardous substances (chemical and radiological) into the air, creeks, streams, and rivers from the Oak Ridge Reservation and the potential of off-site exposure to contaminants downstream. These detailed presentations also included discussions of ATSDR's review and analysis of the Tennessee Department of Health's 1993 Phase I of the Oak Ridge Health Study—Dose Reconstruction Feasibility Study, and 1999 Reports of the Oak Ridge Dose Reconstruction, The Report of Project Task 7—Screening-Level Evaluation of Additional Potential Materials of Concern. These studies evaluated past chemical and radionuclide releases from the Oak Ridge Reservation and the potential of their releases to impact the health of people living near the reservation. Using ATSDR's screening process for evaluating past exposures, ATSDR scientists are conducting public health assessments on the release of and exposure to uranium, iodine 131, mercury, PCBs, radionuclides from White Oak Creek, fluorides, and other topics, such as the TSCA incinerator and off-site groundwater. ATSDR will evaluate past and current off-site exposures to these contaminants. In addition, the EEWG conducted an evaluation of ATSDR's screening process for past exposures. The EEWG's evaluation consisted of a detailed review and understanding of ATSDR's screening presentations to the subcommittee, ATSDR's independent technical reviewers' comments, the subcommittee's review and assessment of technical documents (as needed), and related public concerns or issues (as needed). After completing its evaluation, the EEWG recommended at the February 2002 ORRHES meeting that the ORRHES endorse ATSDR's screening process for determining contaminants of concern for past exposures (1944–1990 data). This endorsement begins with using the state of Tennessee's screening process and associated findings that identified ORR off-site releases warranting further evaluation. The ORRHES approved the EEWG's recommendation to endorse ATSDR's screening evaluation of past exposures. The February 2002 ORRHES meeting minutes are available on the ATSDR Web site at http://www.atsdr.cdc.gov/HAC/oakridge/meet/orr/m8_27.html . Cesium and strontium were first evaluated by the state of Tennessee in its 1993 Phase I of the Oak Ridge Health Study Dose Reconstruction Feasibility Study and then reevaluated in the 1999 Reports of the Oak Ridge Dose Reconstruction, Radionuclide Releases to the Clinch River from White Oak Creek on the Oak Ridge Reservation—an Assessment of Historical Quantities Released, Off-Site Radiation Doses, and Health Risks (referred to as the "Task 4 report"). ATSDR evaluated past, current, and future exposure to cesium and strontium in this public health assessment. Nickel and chromium were evaluated in the 1993 Phase I of the Oak Ridge Health Study—Dose Reconstruction Feasibility Study and reevaluated in the 1999 Reports of the Oak Ridge Dose Reconstruction, The Report of Project Task 7—Screening-Level Evaluation of Additional Potential Materials of Concern (ATSDR et al. 2000; ChemRisk 1999b). The Tennessee Department of Health had the 1993 Phase I of the Oak Ridge Health Study—Dose Reconstruction Feasibility Study reviewed by SENES Oak Ridge in 1995. This report titled A Review of the Preliminary Screening Analysis Carried Out During the Oak Ridge Dose Reconstruction Feasibility Study was evaluated by ATSDR and the EEWG (former PHAWG). See Appendix D for briefs on the 1993 Phase I feasibility study, 1999 Task 4 report, and the 1999 Task 7 report. Copies of the Tennessee Department of Health reports are available at the DOE Information Center located at 475 Oak Ridge Turnpike, Oak Ridge, Tennessee (telephone number: 865-241-4780) or through DOE's public-use database at http://cedr.lbl.gov/DR/dror.html .
17	I had some questions about your study of the hundred and sixteen people in the southern Watts Bar area. I don't know if I am being premature in my questions to you, but did you all come to the conclusion that there was no danger from eating the fish for anything other than PCBs, when that was the only thing you tested for? If your testing was accurate and your conclusions were accurate, why hasn't something changed so far as all of those fish advisories? I don't think the community would mind if you had an advisory on don't eat the turtles.	ATSDR conducted a health consultation in 1996 to evaluate the public health implications of current exposure to chemical and radiological contaminants in the Lower Watts Bar Reservoir surface water, sediment, and fish and the effectiveness of the Department of Energy's (DOE) proposed remedial action plan for protecting public health. ATSDR found that only PCBs in the reservoir fish were of potential public health concern. The current levels of other contaminants in the surface water, sediment, and fish are not a public health hazard. After reviewing current levels of contaminants in the water, in sediment, and in local fish populations, ATSDR concluded that: The levels of PCBs in the Lower Watts Bar Reservoir fish posed a public health concern. Frequent and long-term ingestion of fish from the reservoir posed a moderately increased risk of cancer in adults and increased the possibility of developmental effects in infants whose mothers consumed fish regularly during gestation and while nursing. Turtles in the reservoir might also contain PCBs at levels of public health concern. Current levels of contaminants in the reservoir surface water and sediment were not a public health hazard. The reservoir was safe for swimming, skiing, boating, and other recreational purposes. Drinking water from the municipal water systems, which draw surface water from tributary embayments in the Lower Watts Bar Reservoir and the Tennessee River upstream from the Clinch River and Lower Watts Bar Reservoir, was safe to drink. DOE's selected remedial action was protective of public health. ATSDR recommended that the Lower Watts Bar Reservoir fish advisory remain in effect to minimize exposure to PCBs. ATSDR followed up the 1996 health consultation by conducting the Watts Bar Reservoir Exposure Investigation in March 1998. This study was done to measure actual PCB and mercury levels in people who have eaten large amounts of Watts Bar Reservoir fish or turtles. ATSDR tested for PCBs because previous investigations estimated that people who eat certain fish or turtles might have higher than average levels of PCBs in their bodies and suggested that the levels of PCBs in fish were a public health concern. ATSDR tested the blood samples for mercury because mercury was a historic contaminant of concern. Recent studies, however, have not detected mercury at levels of health concern in surface water, sediments, or fish from the Watts Bar Reservoir. The ATSDR exposure investigation revealed that the 116 study participants who consumed moderate to large amounts of fish and turtles had PCB levels similar to those of the general population. The PCB and mercury levels were less than ATSDR health officials expected for people who consume moderate to large amounts of certain fish or turtles from the Watts Bar Reservoir. Five people (4% of the 116 participants) had elevated serum levels of PCBs (above 20 micrograms per liter), one person had PCB levels above those in the general population, and one person had elevated blood mercury levels (above 10 micrograms per liter). ATSDR health officials believed that health effects were not likely based on the PCB and mercury levels seen in the exposure investigation participants. ATSDR recommended that health education activities be targeted to local health care providers, pregnant and nursing mothers, and any other potentially vulnerable populations to minimize exposure to PCBs. ATSDR developed an instructive brochure on the Tennessee Department of Environment and Conservation (TDEC) fish consumption advisories for the Watts Bar Reservoir. The brochure was the result of the collaborative effort of local citizens, organizations, and state officials. See Appendix D for a brief of the exposure investigation and Section II.F.1. for ATSDR's public health activities related to White Oak Creek radionuclide releases (ATSDR et al. 2000; ORHASP 1999).
18	Since the contamination from fish ingestion will not necessarily be measurable in the bloodstream at high levels at all times, a challenge test is needed to detect it. This was not used by ATSDR and is not normally used in a standard physician's office visit test. The ATSDR study results are countered by other studies, and communities in the southeast whose problems were addressed by ATSDR were not helped.	There are reliable and accurate medical tests that measure the level of mercury in the body by analyzing blood, breast milk, hair, or urine samples. These are not routine clinical tests, but they could be requested from a doctor. Most of these tests do not determine the form of mercury to which an individual is exposed. These clinical tests can show if mercury exposure has occurred, provide an idea as to the extent of exposure, and can be used to assess if harmful health effects are likely to occur, but they cannot tell exactly how much exposure has occurred (ATSDR 1999a). For more information on mercury, review ATSDR's toxicological profile on mercury at http://www.atsdr.cdc.gov/toxprofiles/phs46.html. PCBs are pervasive environmental contaminants that are found in body tissue and fluids of the general population. There are also medical tests that measure the level of PCBs in the body by analyzing blood, body fat, and breast milk. Serum or plasma lipid PCB concentrations are an indicator of PCB body burden. These are not routine clinical tests, but they could be requested from a doctor. These tests can indicate if a person was exposed to PCBs, but they cannot determine the exact amount of exposure, type of PCBs, or if adverse health effects will occur. Though, these tests can indicate whether you have been exposed to PCBs to a greater extent than the general public. Blood tests are the best method for detecting recent exposure to large amounts of PCBs. Thus, a physician with a background in environmental and occupational health should carefully interpret the test results (ATSDR 2000). For more information on PCBs, visit ATSDR's Web site for the PCB toxicological profile at http://www.atsdr.cdc.gov/toxprofiles/phs17.html. Previous investigations identified PCBs in reservoir fish as a possible contaminant of public health concern. TDEC and DOE had detected PCBs at levels up to about 8 ppm in certain species of reservoir fish during past studies. In an investigation on turtles in the Watts Bar Reservoir and the Clinch River, TDEC detected the highest PCB concentrations in the fat tissue (ranged from 0.274 to 516 ppm) of snapping turtles. The PCB concentrations detected in the muscle tissue of turtles ranged from 0.032 to 3.38 ppm. In 1994 and 1996 remedial investigations, based on estimated PCB exposure doses and estimated excess cancer risks for people consuming large amounts of fish over an extended time period, DOE determined that the fish ingestion pathway had the greatest potential to cause adverse health effects in the Lower Watts Bar Reservoir and the Clinch River/Poplar Creek, respectively. ATSDR also conducted a 1996 health consultation on the Lower Watts Bar Reservoir that reached similar conclusions as found in the remedial investigation. None of these studies, however, considered actual blood levels in fish and turtle consumers nor confirmed if people were actually exposed to PCBs or had elevated PCB levels. Because of these reasons and since so many uncertainties are involved in estimating exposure doses and excess cancer risk from ingesting reservoir fish and turtles, ATSDR conducted an exposure investigation to actually measure the serum PCB levels in fish and turtle consumers. In fact, ATSDR knows of no other studies in the Oak Ridge area that measured actual blood levels in community members to evaluate exposures from fish and turtle consumption. For this investigation, ATSDR targeted people who consumed moderate to large amounts of reservoir fish and turtles. Based on the actual measurements of serum PCB levels in participants, only 1 out of 116 had a serum PCB level higher than levels observed in the general population. Therefore, based on actual levels—not theoretical estimates as used in previous studies—of people who consumed moderate to high amounts of fish and turtles from the reservoir, PCB levels were comparable to the general population. See Appendix D for a brief on the 1998 Watts Bar Reservoir Exposure Investigation and a brief on the Turtle Sampling in Watts Bar Reservoir and Clinch River.
19	Concerning studies of PCBs and blood samples in people who eat fish, I wonder how valid the information would be. Do PCBs stay in the blood, for example, and were they are a lot higher, one would presume, right after eating a meal than a week later? Were those factors taken into account in the study?	The 1998 Watts Bar Reservoir Exposure Investigation was a cross-sectional study because it evaluated PCB and mercury exposures at a specific point in time. Blood tests are the best method for detecting exposure to PCBs. Serum or plasma lipid PCB concentrations are indicators of PCB body burden and can indicate whether you have been exposed to PCBs to a greater extent than the general public. In this type of study (a cross-sectional study), PCB and mercury blood levels indicate both chronic and acute (short-term) exposures, depending on recent fish consumption. PCB blood levels are likely to be higher right after eating a fish meal containing PCBs. This factor was taken into account in the exposure investigation. The investigation is discussed in more detail in Section II.F.1. of this document. In addition, ATSDR will address issues solely related to PCBs in a separate public health assessment that will be released in the near future. See Appendix D for a brief on the 1998 Watts Bar Reservoir Exposure Investigation.
20	A community member said there are a couple of other dimensions that will complicate matters but she hopes they will be considered. One is the time frame. The workers and residents who lived nearby in the 50s and 60s had different exposures than now and will have different symptoms now. Also, geographically, the flow of water, the underground aquifer, that sort of thing. The two dimensions are geography and time will complicate this and shouldn't be overlooked. There may be people who lived in different locations and the well water was of different composition.	In this public health assessment, ATSDR evaluates radionuclides released into the surface water in White Oak Creek, and assesses past, current, and future impact from exposures to these radionuclide releases in the water for residents living off the Oak Ridge Reservation within the White Oak Creek study area (the area along the Clinch River and the Lower Watts Bar Reservoir from the Melton Hill Dam to the Watts Bar Dam [see Figure 11]). This PHA evaluates the following key issues and concerns: contacting surface water and sediment (both surface and deep channel) and consuming surface water, milk, game animals, fish, turtles, and homegrown vegetables. In addition to this PHA, ATSDR scientists are conducting public health assessments on the releases of iodine 131, mercury, PCBs, uranium, fluorides, and other topics including off-site groundwater. The geography and characteristics of the aquifer are considered in the groundwater public health assessment available at http://www.atsdr.cdc.gov/HAC/PHA/region_4.html#groundwater. In conducting PHAs, ATSDR scientists are evaluating and analyzing the information, data, and findings from previous studies and investigations to assess the public health implications of past, current, and future exposures.
21	Will exposure investigations be done as they were for PCBs at Watts Bar?	ATSDR is not planning additional exposure investigations at this time. Instead, ATSDR is conducting public health assessments on the releases of iodine 131, mercury, PCBs, uranium, fluorides, and other topics. In conducting these public health assessments, ATSDR scientists are evaluating and analyzing the information, data, and findings from previous studies and investigations to assess the public health implications of past, current, and future exposures. ATSDR uses the public health assessment process to Identify populations (groups of people) off the site who could have been exposed to hazardous substances at levels of health concern, Determine the public health implications of exposure, Address the site-specific health concerns of people in the community, Recommend any needed follow-up public health actions to address exposure, and Communicate ATSDR's findings to the public.
*General Concerns Related to the Oak Ridge Reservation*
22	What is the probability of a clinic for residents closely associated and who live close by incinerators and the Clinch River and East Fork Poplar Creek?	ATSDR is using the public health assessment process to evaluate previous studies and environmental data to determine whether releases of hazardous substances from the Oak Ridge Reservation could have affected the health of people in communities near the reservation. The public health assessment is the primary public health process ATSDR uses to Identify populations (groups of people) off the site who could have been exposed to hazardous substances at levels of health concern, Determine the public health implications of exposure, Address the site-specific health concerns of people in the community, Recommend any needed follow-up public health actions to address exposure, and Communicate ATSDR's findings to the public. ATSDR worked with the Oak Ridge Reservation Health Effects Subcommittee (ORRHES) to ensure that the public health questions of people living in the Oak Ridge Reservation area were answered. In response to community concerns regarding a clinic, the ORRHES Needs Assessment Work Group conducted a comprehensive program review of the various federal agencies to determine whether it was possible to establish an occupational/environmental clinic or another form of clinical intervention near the Oak Ridge Reservation. On August 27, 2002, the ORRHES made the following recommendation to ATSDR. "The Oak Ridge Reservation Health Effects Subcommittee (ORRHES) has determined that discussion of public health activities related to the establishment of a clinic, clinical evaluations, medical monitoring, health surveillance, health studies, and/or biological monitoring is premature. Thus, the ORRHES recommends that formal consideration of these issues be postponed until the ATSDR public health assessment (PHA) process identifies and characterizes an exposure of an off-site population at levels of health concern. If this exposure warrants follow-up public health activities, the ORRHES will then consider these issues in making its recommendations to ATSDR." This ORRHES recommendation was based on the review, evaluation, and understanding of the comprehensive program review presented by the Needs Assessment Work Group at the August 27, 2002, ORRHES meeting. The August 27, 2002, ORRHES meeting minutes are available on ATSDR's Web site at http://www.atsdr.cdc.gov/HAC/oakridge/meet/orr/m8_27.html.
23	Will you screen the effects of the environmental pollutants from the Kingston and Bull Run power plants whose interaction with the ORR concerns many people?	ATSDR is not evaluating all sources of contaminants in the area and is not adding exposures from these other sources. Congress created ATSDR to implement the health related sections of the 1980 Superfund law. ATSDR's congressional mandate is to conduct a public health assessment at EPA's National Priorities List for Uncontrolled Hazardous Waste Sites (NPL). The DOE Oak Ridge Reservation (ORR) is on the NPL. ATSDR's focus is on ORR releases of contaminants to off-site locations. ATSDR is not going to conduct an evaluation of releases of contaminants from other industries in the area. However, environmental samples (air, water, sediment, and soil) collected in and around the ORR may contain contaminants released from other industries in the area (for example, arsenic, mercury, and uranium released from the two large Tennessee Valley Authority [TVA] power plants). ATSDR will evaluate the levels of contaminants in these samples regardless of the source of the contaminants. If ATSDR identifies contaminants in off-site locations during its assessment that are of public health concern, then ATSDR will address exposures to these contaminants in the PHA.
24	This second paper in Radiation Research (after the Mangano paper) was a study of the mortality of 106,020 workers employed between 1943 and 1985 at the federal nuclear plants in Oak Ridge (who also live in communities around ORR). This second paper DID NOT find an increase in leukemia deaths relative to U.S. white males. A smaller group of 28,347 white males employed at X-10 or Y-12 who were at risk for exposure to external penetrating radiation was examined to determine if there was a relationship between rates of death from selected causes and level of radiation dose. There was no evidence for an association between leukemia deaths and external radiation. Leukemia death rates for X-10 workers were higher than U.S. rates and other similar Oak Ridge workers.	ATSDR is conducting public health assessments to evaluate whether the releases of contaminants from the Oak Ridge Reservation could be harmful to people who live in communities near the reservation. This assessment focuses on exposures to contaminants that occurred off the reservation. ATSDR does not evaluate health issues related to workplace exposures. ATSDR did, however, conduct an assessment of cancer incidence that evaluated cancers in the eight counties surrounding the reservation. For the review, ATSDR used cancer incidence data from the state of Tennessee's cancer registry. The assessment of cancer incidence report is available at http://www.atsdr.cdc.gov/HAC/oakridge/phact/cancer_oakridge/index.html. Information specific to workers can be found on the Internet at http://cedr.lbl.gov . This site provides information about epidemiologic studies of U.S. Department of Energy workers, including studies of workers at the Y-12, X-10, and K-25 sites.

¹⁵ Please see http://www.utah.edu/radiobiology/mayak/index.html#toc

for additional information.
¹⁶ Please see http://www.inea.org.br/bridradia.htm

for more details.

Next Section Table of Contents

PUBLIC HEALTH ASSESSMENT

WHITE OAK CREEK RADIONUCLIDE RELEASES OAK RIDGE RESERVATION (US DOE) OAK RIDGE, ROANE COUNTY, TENNESSEE

IV. PUBLIC HEALTH IMPLICATIONS

V. HEALTH OUTCOME DATA EVALUATION

VI. COMMUNITY HEALTH CONCERNS

WHITE OAK CREEK RADIONUCLIDE RELEASES
OAK RIDGE RESERVATION (US DOE)
OAK RIDGE, ROANE COUNTY, TENNESSEE