Public Comment

ATSDR's Response

ATSDR's Health Guidelines for Chemical Effects

53

Please explain why the MRL of the insoluble forms of uranium, rather than soluble. (p. 7, line 31)

As noted on page 58 of the PHA, the predominant chemical form of uranium released into the air from the Y-12 plant was highly insoluble uranium oxide (ChemRisk 1999).

54

Figure 9 shows a radiogenic cancer comparison value for internal radiation dose, stated in terms of mrem. Then, for airborne chemical exposure, and external concentration, designated an MRL, is given in units of mg/m**3. Then, for past soil and surface water contamination, an internal chemical dose rate, designated and MRL, is given in units of mg/kg/day. Technically, this discussion lacks logic, due to the unexplained difference in units used for the two MRLs for past chemical exposure. Table 25 could be used to good advantage to improve the explanation. Clearly the units of dose for radiation exposure and chemicals exposure cannot be the same. But why do the units associated with air as the pathway represent an external concentration, and then those associated with soil and surface water as the pathways represent an internal, mass-based, dose rate? Can't all the doses for internal chemical exposure be expressed in the same units? When communicating with the public, you can't just quote the techies' statements verbatim. You first have to make sure that they are internally consistent and make sense, both in terms of cause-and-effect, and with respect to the numbers and the units associated with those numbers.

The main theme of the comments concerns the disparate units of measurement used to quantify chemical exposures, without efforts to either eliminate the disparity or to explain it. [The commenter provided a table that could not easily be inserted into this table. Therefore, it is provided as Table A at the end of this table.] [ATSDR staff] state that the units used for each pathway are those describing the quantities that have been experimentally correlated, directly or indirectly, with health effects.

There seems to be inconsistencies between the interpretations of Figs. 16, 17, 25 & 26. Fig. 16 is interpreted to indicate that no adverse health effects due to airborne uranium were caused to occur in the past in residents of Scarboro, because the average airborne concentrations of uranium in Scarboro were always less than the minimum risk level (MRL). Then, Fig. 17 is interpreted to indicate that, even thought dose rates for internal absorption in 6-year olds could have been higher than MRL between 1953 and 1973, still no adverse health effects due to soil and water contamination occurred in the past because the exposure levels were always less than the lowest observed adverse effect level (LOAEL). Then for evaluating current risks of adverse health effects due to soil contamination, by means of Figs. 25 and 26, you revert to using the MRL as a criterion, because all the calculated current doses rates are below it. Finally, for evaluating current risks of adverse health effects due to water contamination, yet another set of units is introduced. This time the units are for an external concentration, in mg/L, instead of the internal dose rate of mg/kg/day shown in Fig. 17. Furthermore, the safety criterion for water as the pathway changes from an MRL to an Environmental Media Evaluation Guide. These unexplained changes in units and criteria are exasperating, because they make it impossible to develop a perspective on the subject. Is there no discipline in the field of environmental science that prescribes an agreed-upon set of units and criteria for a given subject? You can't just switch back and forth between units and criteria and retain credibility, especially, in this case, between an MRL and a LOAEL. If the MRL means what it says, then any exposure above it creates some risk, whether or not any adverse health effects have yet been observed. Therefore, the answer to the last question on page 1 cannot be an unequivocal "no". You seem to have put yourselves between a rock and a hard place, by making a statement that doesn't agree with the numbers.

Part of the problem involving criteria relates to their definitions, as given in Appendix A of the PHA. The ATSDR term Minimum Risk Level (MRL) is defined as a dose below which adverse (noncancerous) health effects are unlikely. But a statement is added to the effect that MRLs should not be used as predictors of adverse health effects, without saying whether or not there is supposed to be a margin between the MRL and the dose at which harmful effects become likely. Notwithstanding this warning, the text of the Brief implicitly uses MRLs as predictors of harmful health effects, if for no other reason than not stating a deliberate margin between and MRL and a LOAEL. Then there is an analogous term defined by EPA, using a deliberate safety factor, as a Reference Dose (RfD), which is a dose unlikely to cause harm in humans. In addition, there is the Lowest-Observed-Adverse-Effect Level (LOAEL), the definition of which is self-evident. Finally, there is the No-Observed-Adverse-Effect Level (NOAEL), the definition of which is also self-evident. This latter criterion in no used in the Brief. The various criteria discussed above should be identified by labels in Fig.9, or in another figure, and then these terms should be used in the brief only in strict accordance with their definitions. By so doing, the correct criteria for judging safety will be more evident and understandable.

Because uranium has both radioactive and chemical properties, ATSDR evaluated both radiation and chemical aspects of uranium exposure. As explained in Appendix A (ATSDR's Glossary) the dose for chemicals that are not radioactive is the amount of a substance to which a person is exposed over some time period. It is often expressed as milligrams (a measure of quantity) per kilogram (a measure of body weight) per day (a measure of time). The dose for radioactive chemicals is the amount of energy from radiation that is actually absorbed by the body. The radiation dose is expressed in mrem and mrem/year. The corresponding screening values and health guidelines retain the same units.

ATSDR's public health assessment process involves two levels of screening and a weight-of-evidence "decision-making" evaluation (see Figure 7). The first step in identifying contaminants that warrant further evaluation is to compare the concentrations detected in the environment to media-specific comparison values (such as the environmental media evaluation guides [EMEGs] and risk-based concentration [RBC] values given in Table 2). Each media-specific concentration is expressed in the appropriate units (µg/m³ for air, µg/L for water, and mg/kg for soil and fish). As explained in the Evaluating Exposures section (Section III.A.2.), comparison values reflect concentrations that are much lower than those that have been observed to cause adverse health effects. Thus, comparison values are protective of public health in essentially all exposure situations. As a result, concentrations detected at or below ATSDR's comparison values are not considered to warrant health concern. Therefore, if the concentration in the environment is below the comparison value, no further evaluation is conducted.

If the concentration exceeds the comparison value, ATSDR further evaluates the exposure potential by calculating exposure doses (defined above). During this second level of screening, ATSDR compares the calculated dose to a health guideline (such as the MRL values given in Table 3). While ATSDR's oral MRLs are expressed as a dose per unit of bodyweight (mg/kg/day), the inhalation MRLs are expressed as air concentrations (milligrams per cubic meter). As explained in the Evaluating Exposures section (Section III.A.2.), regardless of the media being evaluated, MRLs are an estimate of the daily human exposure to a hazardous substance that is likely to be without appreciable risk of adverse noncancer health effects over a specified duration of exposure. They have built-in uncertainty or safety factors, making them considerably lower than levels at which health effects have been observed. Estimated doses that are less than the MRL are not considered to be of health concern.

More information about the development of ATSDR's MRLs can be found in Appendix A of the Uranium and Ionizing Radiation Toxicological Profiles at the following Web site: http://www.atsdr.cdc.gov/toxpro2.html#-T-.

If the calculated exposure dose is higher than the MRL, it does not automatically mean harmful health effects will occur. Rather, this is an indication that ATSDR should further examine the harmful effect levels reported in the scientific literature and more fully review exposure potential. In this "decision-making" step, ATSDR conducts a weight-of-evidence analysis to evaluate the public health implications. ATSDR uses the best medical and toxicologic information available to determine the health effects that may result from exposure to contaminants at a site (such as LOAELs [lowest observed adverse effect levels] and NOAELs [no observed adverse effect levels]). Such information is usually derived from ATSDR's chemical-specific Toxicological Profiles (available at the following Web site: http://www.atsdr.cdc.gov/toxpro2.html#-T-).

The step in which the various uranium scenarios were screened out (as safe) dictates the guideline and units that are presented during the health evaluation. For example, as shown in Figure 27, the average uranium air concentrations for current chemical exposure were well below the MRL (appropriately given as a concentration). Therefore, no further evaluation was required and ATSDR did not calculate exposure doses. Even though the air concentrations can be converted into a dose, it is an unnecessary step.

An interactive program that provides an overview of the public health assessment process ATSDR uses to evaluate whether people will be harmed by hazardous materials is available at: http://www.atsdr.cdc.gov/training/public-health-assessment-overview/html/index.html.

The text on the public health assessment process has been clarified in the final PHA to assist in understanding the two levels of screening and a weight-of-evidence "decision-making" evaluation.

55

[ATSDR staff] further explained that, in the case of some but not all contaminates, relationships between external concentrations and internal doses do exist. From the viewpoint of the public, I believe that it would be desirable to use these relationships, if they exist, in order to create links that are as direct as possible between the quantities being discussed and their effects on human health. If such relationships do not exist, then at the least, a statement that correlations between external concentrations and health effects do exist, but relationships between external concentrations and internal doses don't, would be a helpful and clarifying addition to the brief. In the case of uranium, Section 8 of the Summary Report for the Oak Ridge Dose Reconstruction Project indicates that biokinetic models do exist by which environmental concentrations of uranium can be used to estimate body burdens of that element.

ATSDR will consider your suggestion.

56

In your discussion of chemical toxicity, you did not include the RfD of 0.6 micrograms per kg per day for uranium used in the Radionuclides in Drinking Water Final Regulation. See below:

It should also be noted that ATSDR references an oral MRL of 2 micrograms of uranium per kilogram of body weight per day, a 1989 EPA RfD for uranium of 3.0 micrograms of uranium per kilogram of body weight per day. It also references a LOAEL of 0.05 milligrams per kilogram of body weight per day. These are both based on animal studies alone.

In 1998, EPA sponsored a workshop in Washington, DC, attended by an ATSDR representative, among others. Based on data developed at this workshop, EPA used an RfD of 0.6 micrograms of uranium per kilogram of body weight per day in its Drinking Water Regulations (Part II Environmental Protection Agency, $0 CFR Parts 9, 141,and 142, National Primary Drinking Water Regulations: Radionuclides; Final Rule. Federal Register, Vol. 65 No. 236, pp. 76708-76753; Government Printing Office, Washington, DC; December 7, 2000.) This decision was supported by data from studies of two limited Canadian populations presented at the workshop. A more recent Finnish study of a larger population confirmed that uranium intake in water does have effects at these low exposure levels. (Kurttio, P., et al. Renal Effects of Uranium in Drinking Water, Environmental Health Perspectives, 110: 337-342, 2002). Kurttio, et al. Also reported a "....lack of an obvious threshold for the nephrotoxic effect and possible heterogeneity of effect within populations,...."

This suggests a greater need for caution on the question of chemical toxicity than is evidenced in ATSDR's analysis. Scarboro Uranium exposures are not necessarily safe.

Scarboro uranium exposures are safe. As explained in several places in the PHA (see pages 71, 86, and 95), East Fork Poplar Creek (EFPC) is not used as a drinking water source. The city of Oak Ridge, including Scarboro, is served by municipal water, which must meet specific drinking water quality standards set by EPA. Under the authorization of the Safe Drinking Water Act, EPA has set national health-based standards to protect drinking water and its sources.

Regardless of the fact that EFPC is not used as a drinking water source, the total uranium mean concentrations in surface water from Scarboro ditches and Lower EFPC are below EPA's maximum contaminant level (MCL) for uranium (30 µg/L). In addition, Table 16 shows that the mean total uranium concentrations for surface water samples collected from Scarboro ditches and Lower EFPC are below ATSDR's EMEG of 20 µg/L. Therefore, the concentrations of uranium that people might be exposed to are not of health concern.

As explained in the response to comment 54, comparing the concentration of uranium detected in the water to the EMEG is the first level of the screening process. EMEGs reflect concentrations that are much lower than those that have been observed to cause adverse health effects and are protective of public health in essentially all exposure situations. As a result, concentrations detected at or below this concentration are not considered to warrant health concern. Therefore, because the concentrations were below the environmental guideline, the levels are considered safe. No further analysis is warranted (i.e., no doses need to be calculated and compared to the reference dose [RfD] or MRL).

As is the case with ATSDR's MRLs, EPA's RfDs (Reference Dose: an EPA estimate, with uncertainty or safety factors built in, of the daily lifetime dose of a substance that is unlikely to cause harm in humans; see Appendix A) are screening values that represent an exposure dose considerably lower than levels at which health effects have been observed. If the calculated exposure dose is higher than the MRL or RfD, it does not automatically mean harmful health effects will occur. Rather, this is an indication that ATSDR should further examine the harmful effect levels reported in the scientific literature and more fully review exposure potential (see response to comment 54 for additional details). This is exactly what ATSDR did for past exposures to uranium through ingestion of soil and surface water (see the Past Exposure via Ingestion discussion under the Past Chemical Effects discussion (Section III.B.1.b.)).

The following discusses the basis for EPA's and ATSDR's health guidelines mentioned by the commenter:

• The RfD of 0.6 µg/kg/day (0.0006 mg/kg/day) is based on a LOAEL of 0.06 mg/kg/day in rats and LOAELs of 0.02 to 0.1 mg/kg/day in humans (Federal Register 2000). EPA applied an uncertainty factor of 100 (3 for intraspecies variability, 10 for interspecies variability, and 3 for use of a LOAEL) to estimate the RfD.



• EPA's RfD according to the Integrated Risk Information System (IRIS) is 0.003 mg/kg/day based on a LOAEL of 2.8 mg/kg/day in rabbits, rats, and dogs (EPA 1989). An uncertainty factor of 1,000 was applied to the LOAEL to reflect 10 for both intraspecies and interspecies variability to the toxicity of the chemical in lieu of specific data and 10 for use with a LOAEL from an animal study.



• As discussed on page 63, ATSDR's MRL (0.002 mg/kg/day) is based on a LOAEL of 0.05 mg/kg/day in rabbits (ATSDR 1999a). An uncertainty factor of 30 (3 for use of a minimal LOAEL and 10 for human variability) was applied to the LOAEL to derive the MRL. As mentioned in the response to comment 156, MRLs undergo a rigorous review process.

All of the health effects levels (LOAELs) cited by EPA and ATSDR as the most appropriate for deriving their health guidance (RfDs and MRL) are higher than the doses calculated for past ingestion of uranium through the soil and surface water pathways (see Table 13 and Figure 20). Given the conservative nature of these estimates, ATSDR still concludes that Scarboro uranium levels were also safe in the past.

Discussion of Health Outcome Data

57

The report also neglects to explain why the Oak Ridge population remained constant in the 1960-2000 time frame, while the footprint of Oak Ridge Hospital zone quadrupled in size. The report neglects to tell the growth of the number of medical professionals in Oak Ridge, which would directly relate to the change in health impact on the region.

My comments to make a proper report would be to provide with the population statistics of Oak Ridge, the same year to year data on the number of type of medical practitioners at Oak Ridge's Hospital and medical complex.

There are many factors relating to the number of medical professionals in a community. ATSDR does not believe there is a correlation between the number of medical professionals and health impacts on the region.

As the 1960 Oak Ridge Hospital developed into the 2003 Methodist Medical Center, its drawing area has grown to include four rural counties to the northwest and its services have expanded into several spatiality areas. Any changes in health impacts due to these extensions are not related to the level of uranium in the environment.

58

The report also neglects news articles, which I saw in the mid-80's, that showed three times the death rates for specific illnesses at the Oak Ridge's Hospital compared to ones in Knoxville.

Based on a recommendation by the ORRHES, ATSDR is currently conducting a cancer incidence review for the eight counties surrounding the ORR.

In Appendix B of the PHA, ATSDR summarizes two health statistics reviews conducted by the Tennessee Department of Health (TDOH):

• In 1992, the TDOH conducted a health statistics review to compare the cancer incidence rates (during the period of 1988 to 1990) of counties surrounding the ORR to those from the rest of the state. Findings of the review are in a TDOH memorandum dated October 19, 1992, from Mary Layne Van Cleave to Dr. Mary Yarbrough.



• In 1994, TDOH (in consultation with Peru Thapa, MD, MPH, from the Vanderbilt University School of Medicine) conducted a health statistics review of mortality rates for amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), and other selected health outcomes. The results of the review were reported by the TDOH at the ORHASP public meeting on August 18, 1994.

It should be noted that the Methodist Medical Center draws from areas that are far removed from the ORR (see response to comment 58).

59

A large part of the reason for ATSDR to become involved in Oak Ridge was due to the exposure of the community of Scarboro in the Tennessean newspaper and the rates of illness in children, particularly asthma.

ATSDR's Involvement at the ORR

ATSDR is involved with the ORR because it is listed on EPA's National Priorities List (NPL). Since 1986, ATSDR has been required by law to conduct a PHA at each of the sites on the NPL (as noted on page i of Foreword of the PHA). Additionally, ATSDR embraces the philosophy that community involvement is a key component of the public health assessment process.

Since the community members have a high interest and concern regarding health issues at the ORR, ATSDR and the Centers for Disease Control and Prevention (CDC) established ORRHES in 1999 to provide a forum for communication and collaboration between citizens and the agencies that are evaluating public health issues and conducting public health activities at the ORR. ATSDR's community involvement activities promote collaboration between ATSDR scientists, community members, and other agencies. These activities also provide opportunities for community members to have a role in ATSDR's public health assessment process. Figures 4 and 5 in the PHA depict the process whereby the ORRHES, the PHAWG, and the public participate and provide input into the ATSDR public health assessment process.

Also, responding to community health concerns is an essential part of ATSDR's overall mission and commitment to public health. ATSDR actively gathers comments and other information from the people who live near the ORR and will be addressing these community health concerns in the ORR PHAs that are related to those concerns (see the Section VI of the PHA and response to comment 4 for more information about ATSDR's Community Health Concerns Database and ATSDR's response to community concern).

Scarboro Community Health Investigation

In response to a 1997 newspaper article describing the respiratory illness among children in Scarboro, the CDC and Tennessee Department of Health conducted the Scarboro Community Health Investigation. In Section II.F.3 of the PHA, ATSDR summarizes the Scarboro health investigation conducted in 1998 (by the CDC, TDOH, the Oak Ridge medical community, and the Morehouse School of Medicine) to investigate a reported excess of respiratory illness among children in the Scarboro community. Physical examinations were conducted and did not indicate any unusual pattern of illness among children in Scarboro. The illnesses that were detected were not more severe than would be expected and were typical of those that might be found in any community. The findings of examinations essentially confirmed the results of the community health survey. The newspaper allegations were not borne out by the Scarboro health investigation.

In addition, the asthma rate among children in Scarboro was compared to national estimates among all children aged 0–18 years and among African American children aged 0–18 years. The wheezing rate among children in Scarboro was compared to international estimates.

60

The news was largely connected to a Dr. Bill Reid, who saw elevated immune system parameters in Oak Ridge, and his wife Sandra that made these issues public. The plants have long polluted and damaged the workers health and the medical care for these workers awry with medical misdiagnosis and avoiding measurement of immune system parameters.

It would then appear proper to look at the immune system effects and mechanisms in any health assessment.

In Appendix B, ATSDR summarizes the clinical laboratory analysis and review that were conducted in 1992 and 1993 by ATSDR and the National Center for Environmental Health (NCEH) in response to concerns raised by an Oak Ridge physician. ATSDR concluded that this case series did not provide sufficient evidence to associate low levels of metals with these diseases. The TDOH came to the same conclusion.

Additionally, as summarized in Appendix B, the TDOH conducted two health statistics reviews (in 1992 and 1994) of cancer incidence rates for the period between 1988 and 1990. The review covered the counties surrounding the ORR and examined mortality rates for amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), and other selected health outcomes (see the response to comment 58).

61

My comments to make a proper report would be to...discuss that metals are connected to damage to the immune system that lead to varied pathogen presence in the body that add to health effects.

The discussion of the cytokine factors in lung related illness is required for proper reporting. It is well established that fine particulates and chemicals set off lung immune factors and any additional environmental factors can trigger these effects to stronger degrees. In the community of Scarboro, this effect stems partially from uranium emissions. The uranium emissions stem from Y-12's uranium processing, the Y-12 coal plant, the K-25 plant, and the two large TVA coal plants used to power these DOE facilities. All these emissions are cause for concern and any single source additional exposures from Y-12 only exasperate these problems.

The following information was obtained from the Toxicological Profile for Uranium:

"Animal studies in a number of species and using a variety of compounds confirm that uranium is a nephrotoxin... The kidneys have been identified as the most sensitive target of uranium toxicosis, consistent with the metallotoxic action of a heavy metal... All of the MRLs derived for uranium are based on renal effects, the most sensitive toxic end point" (ATSDR 1999a).

"Although no studies were located that specifically tested immunological effects in humans following inhalation exposure to uranium, all epidemiologic studies of workers in uranium mines and fuel fabrication plants showed no increased incidence of death due to diseases of the immune system (Brown and Bloom 1987; Checkoway et al. 1988; Keane and Polednak 1983; Polednak and Frome 1981). Human studies that assessed damage to cellular immune components following inhalation exposure to uranium found no clear evidence of an immunotoxic potential for uranium. No association was found between the uranium exposure and the development of abnormal leukocytes in workers employed for 12–18 years at a nuclear fuels production facility (Cragle et al. 1988)... There is some evidence from animal studies that exposure to >90% enriched uranium may affect the immune system. Adverse effects reported from such exposures include damage to the interstitium of the lungs (fibrosis) and cardiovascular abnormalities (friable vessels). However, access to U 235 enriched or other high specific-activity uranium is strictly regulated by the NRC and the U.S. Department of Energy (DOE). Therefore, the potential for human exposure to this level of radioactivity is limited to rare accidental releases in the workplace... No information was located regarding the effects of uranium on the immune system in humans following oral exposure for any duration. In laboratory animals, oral exposure of rats, mice, and rabbits to uranium had no significant effect on immune system function" (ATSDR 1999a).

"Human and animal studies have shown that long-term retention in the lungs of large quantities of inhaled insoluble uranium particles (e.g., carnotite dust [4% uranium as uranium dioxide and triuranium octaoxide, 80–90% quartz, and <10% feldspar]) can lead to serious respiratory effects. However, animals exposed to high doses of purified uranium (as uranyl nitrate hexahydrate, uranium tetrachloride, uranium dioxide, uranium trioxide, uranium tetraoxide, uranium fluoride, or uranium acetate) through the inhalation or oral route in acute-, intermediate-, or chronic-duration exposures failed to develop these respiratory ailments. The lack of significant pulmonary injury in animal studies with insoluble compounds indicates that other factors, such as diverse inorganic particle abrasion or chemical reactions, may contribute to these effects" (ATSDR 1999a).

Please also see the responses to comments 58 through 60.

62

The discussion for uranium should also go on to discuss lung retention and migration of uranium into the lymph nodes and also mentionable that uranium oxides retain in the sentinel lymph nodes for decades. The lymph nodes are the sensing zones of the immune system. It is here type 1 cytokine secretory cells, like stationery macrophages, are situated. It is not only that uranium that is pulled into these lymph nodes, it is a plethora of particles and chemicals that cause synergism to trigger inflammatory cytokine's of these immune cells. Failure to discuss this mechanism is scientific malpractice for health assessment. It is also scientific fraud and abuse.

My comments to make a proper report would be to...include the information on the lymph node processes for uranium migration that directly relates to the immunity activation related illness in Scarboro and Oak Ridge town.

The following information was obtained from the Toxicological Profile for Uranium:

"Once in the blood, uranium is distributed to the organs of the body. Uranium in body fluids generally exists as the uranyl ion (UO2)2+ complexed with anions such as citrate and bicarbonate. Approximately 67% of uranium in the blood is filtered in the kidneys and leaves the body in urine within 24 hours; the remainder distributes to tissues. Uranium preferentially distributes to bone, liver, and kidney. Half-times for retention of uranium are estimated to be 11 days in bone and 2–6 days in the kidney... [However,] the less soluble uranium particles may remain in the lungs and in the regional lymph nodes for weeks (uranium trioxide, uranium tetrafluoride, uranium tetrachloride) to years (uranium dioxide, triuranium octaoxide)... The human body burden of uranium is approximately 90 µg; it is estimated that 66% of this total is in the skeleton, 16% in the liver, 8% in the kidneys, and 10% in other tissues. The large majority of [ingested] uranium (>95%) that enters the body is not absorbed and is eliminated from the body via the feces. Excretion of absorbed uranium is mainly via the kidney."

Please also see the responses to comments 58 through 61.

63

It would be a lie for ATSDR to claim there is "no" health concern for uranium from Y-12, as differential amounts can trigger immunity cytokine lung damage factors.

My comments to make a proper report would be to...remove the comments that uranium causes "no" health effects.

In the Conclusion section (Section VIII.) of the PHA, ATSDR concluded that the levels of uranium released from the Y-12 plant in the past and currently would not result in harmful health effects for either adults or children living near the Y-12 plant, including the city of Oak Ridge and the Scarboro community. ATSDR has categorized this site as having no apparent public health hazard from exposure to uranium. ATSDR's category of no apparent public health hazard means that people could be or were exposed, but the level of exposure would not likely result in adverse health effects. The Y-12 uranium releases are not a health hazard to the people living near the Y-12 plant.

64

It would be proper report technique to discuss the mechanisms for why asthma occurs in children and related occupation asthma information. This would mean that the report should discuss the effects of particulate's and chemical's, like HF, and how these deposit in the lungs and trigger immune system cytokine's and long term inflammation.

In Section II.F.3, ATSDR summarizes the Scarboro community health investigation conducted in 1998 (by the CDC, TDOH, the Oak Ridge medical community, and the Morehouse School of Medicine) to investigate a reported excess of respiratory illness among children in the Scarboro community. Physical examinations were conducted and did not indicate any unusual pattern of illness among children in Scarboro. The illnesses that were detected were not more severe than would be expected and were typical of those that might be found in any community. The findings of examinations essentially confirmed the results of the community health survey.

As mentioned several times (e.g., pages 2 and 31), this PHA evaluates community health concerns and issues associated with the uranium releases from the Y-12 plant. The release and exposure to other contaminants of concern (such as mercury, iodine-131, PCBs, uranium from the K-25 facility, and fluorides) are not addressed in this document. These contaminants and other topics will be evaluated by ATSDR in separate PHAs.

65

The report also fails to mention that the State of Tennessee, in looking at the asthma rates, compared Scarboro to large polluted cities asthma rates.

As discussed in Section II.F. of the PHA, the asthma rate among children in Scarboro was compared to national estimates among all children aged 0–18 years and among African American children aged 0–18 years. The wheezing rate among children in Scarboro was compared to international estimates.

66

This has not even been mentioned in your sub-standard report that fails to follow standards and practice and standards of care for proper health assessment. Such an omission should be termed fraud and abuse.

ATSDR is required by law to conduct a PHA at the ORR because it is listed on the NPL. In 1980, the U.S. Congress created ATSDR to implement the health-related sections of the laws that protect the public from hazardous waste and environmental spills of hazardous substances. The Comprehensive Environmental Remediation, Compensation, and Liability (CERCLA), commonly known as the "Superfund" Act, provided a congressional mandate to clean up abandoned and inactive hazardous waste sites and to provide federal assistance in emergencies involving toxic substances. As the lead public health agency for implementing the health-related provisions of CERCLA, ATSDR is charged under the Superfund Act to assess the presence and nature of health hazards at specific Superfund sites, help reduce or prevent further exposure, and expand the knowledge base about health effects related to exposure to hazardous substances (as noted in the response to community concern #9).

The procedures and evaluations conducted by ATSDR follow the guidelines set forth in the Public Health Assessment Guidance Manual (available at the following Web site: http://www.atsdr.cdc.gov/HAC/HAGM/). The manual is a guidance document for health assessors both at ATSDR and in the states. It outlines the health assessment process and provides information to the health assessors on different technical and scientific aspects of performing PHAs.

An interactive program that provides an overview of the public health assessment process ATSDR uses to evaluate whether people will be harmed by hazardous materials is available at: http://www.atsdr.cdc.gov/training/public-health-assessment-overview/html/index.html.

Toxicological profiles are ATSDR documents that examine, summarize, and interpret information about a hazardous substance to determine harmful levels of exposure and associated health effects. ATSDR relied on the information presented in the Toxicological Profiles for Uranium (ATSDR 1999a) and Ionizing Radiation (ATSDR 1999b). Every toxicological profile is prepared in accordance with guidelines developed by ATSDR and EPA, is released for public comment, and undergoes a rigorous review process (Health Effects/MRL Workgroup reviews within the Division of Toxicology, expert panel peer reviews, and agency-wide MRL Workgroup reviews, with participation from other federal agencies, such as the EPA, and comments from the public).

67

I would recommend that ATSDR postpone making formal conclusions about the public health significance of atmospheric releases of uranium from the Y-12 facility at Oak Ridge without first considering the magnitude and uncertainty of the absorbed organ dose, as a function of year and age at time of exposure.

ATSDR did calculate organ-specific doses, when appropriate. Please see Table 15 and Table 19 for estimated doses to the lung and bone.

68

I would recommend that ATSDR postpone making formal conclusions about the public health significance of atmospheric releases of uranium from the Y-12 facility at Oak Ridge without first considering the magnitude and uncertainty associated with the conversion of organ dose to cancer and non-cancer health risk, including uncertainty in the tissue and radiation weighting factors, and the uncertainty in the low dose and low dose rate effectiveness factor for high LET radiation.

As we have previously stated, the Task 6 report was a screening evaluation that routinely and appropriately used several layers of conservatism and protective assumptions and approaches in estimating concentrations and doses. These estimated concentrations and doses are at a magnitude where we believe a quantitative uncertainty analysis is not warranted. For additional information on uncertainty analysis see ATSDR's response to comment 81.

69

The issues of metal oxides entering the body happens for multiple metals in Oak Ridge and examples are uranium from the DOE processes and from coal emissions, mercury from Y-12 Li-6 enrichment and coal emissions, and even beryllium metals from Y-12. Metal oxides cause problems because of their long internalization time in lymph nodes due to their insolubility.

ATSDR agrees that "less soluble uranium particles may remain in the lungs and in the regional lymph nodes for weeks (uranium trioxide, uranium tetrafluoride, uranium tetrachloride) to years (uranium dioxide, triuranium octaoxide)" (ATSDR 1999a). However, "animal studies in a number of species and using a variety of compounds confirm that uranium is a nephrotoxin... The kidneys have been identified as the most sensitive target of uranium toxicosis, consistent with the metallotoxic action of a heavy metal... [and] all of the MRLs derived for uranium are based on renal effects, the most sensitive toxic end point" (ATSDR 1999a).

70

The long internalization effects also occur from fluoride'' exposures, which tend to form calcium-fluoride in the body and like long term internalization, similar to insoluble metal oxides. Fluorides exposure stem for the uranium processes at Y-12, K-25, the emissions from TVA's power plants, fluoridated public water, and rising levels in the food chain.

My comments to make a proper report would be to...discuss the fluorides effects on increasing the metals and uranium retention due to reduction of macrophage activity that helps clear these metals. Discuss the effects of fluorides on the parathyroid gland, which change calcium and metal retention. The effects of metals and fluorides on cell mitochondria. Include the synergism effects of uranium with other metals and fluorides.

Oak Ridge is known for thyroid damage connected to fluorides. Fluorides also causes higher retention of toxic metals, like uranium, due to damage to the macrophage processes. The report fails to mention these effects, and the fluoride synergism with uranium is a very serious oversight.

The ATSDR report also makes use of the ORHASP panel studies, which also have a number of flaws. ORHASP has tried to loose the long term and extreme releases of UF-6 from the K-25 gas diffusion plant. These UF-6 releases add to the local uranium levels and the chemical exposure to HF and fluorides. Fluorides add to the thyroid damage factors, in addition to the multiple I-131 releases in the area. The K-25 analysis has yet to release the mass balance numbers for fluorides and uranium releases that not only damaged health, but the trees in the area.

As mentioned several times (e.g., pages 2 and 31), this PHA evaluates community health concerns and issues associated with the uranium releases from the Y-12 plant. The release and exposure to other contaminants of concern are not addressed in this document. Exposure to fluorides and uranium released from the K-25 facility and iodine-131 released from the X-10 site will be evaluated by ATSDR in separate PHAs.

ATSDR scientists will also conduct PHAs on the following releases and issues: Y-12 releases of mercury, X-10 release of radionuclides from White Oak Creek, PCBs released from all three facilities, releases from the TSCA incinerator, and off-site groundwater. ATSDR is also screening current (1990 to 2003) environmental data to determine whether additional chemicals will require further evaluation.

71

The discussion of Y-12 uranium releases should also mention all the other sources for uranium emissions in the area.

As mentioned several times (e.g., pages 2 and 31), this PHA evaluates community health concerns and issues associated with the uranium releases from the Y-12 plant. As mentioned on pages 68 and 82 of the PHA, "fossil fuel plants, such as coal burning plants, release naturally occurring radioactive materials through their stacks. Because the Bull Run and Kingston Steam Plants are in the vicinity of Oak Ridge, these facilities could be impacting the uranium analyses performed in Oak Ridge. ATSDR could not locate specific information about these plants from the Tennessee Valley Authority. The agency did, however, locate information from a peer-reviewed publication that reported the typical concentrations of uranium in coal ash and fly ash. These values were 4 picocuries per gram (pCi/g) and 5.4 pCi/g, respectively (Stranden 1985)."

Exposure to uranium released from the K-25 facility will be evaluated by ATSDR in a separate PHA.

72

The uranium emissions are metal oxides and the toxic metal effects would dominate.

ATSDR agrees "natural and depleted uranium are only weakly radioactive and are not likely to cause cancer from their radiation...animal studies in a number of species and using a variety of compounds confirm that uranium is a nephrotoxin and that the most sensitive organ is the kidney... The chance of getting cancer is greater if you are exposed to enriched uranium, because it is more radioactive than natural uranium... Enriched uranium is considered to be more of a radiological than a chemical hazard" (ATSDR 1999a).

73

The ATSDR report mentions the TSCA incinerator's uranium emissions, but fails to mention the incinerator burns unary-fluorides to de-water them and in the 1994 time frame they burned some 5 million pounds of uranium. The incinerator emitted uranium, fluorides, and HF and in this same time frame all the downwind pine trees of in the incinerator died. The plant tried to field it was pine beetles, but when I pointed out to the DNFSB that this was fraud, these signs cam down quickly. Even Y-12 has reduced its HF emissions by changing the Y-12 salt shop or the HF uranium processing zone to total air scrubbing to reduce HF emissions that damage the workers, Scarboro and Oak Ridge health.

As mentioned several times (e.g., pages 2 and 31), this PHA evaluates community health concerns and issues associated with the uranium releases from the Y-12 plant. A separate PHA will be conducted to evaluate releases from the TSCA incinerator.

ATSDR scientists will also conduct PHAs on the following releases and issues: 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, PCBs released from all three facilities, and off-site groundwater. ATSDR is also screening current (1990 to 2003) environmental data to determine whether additional chemicals will require further evaluation.

74

I would recommend that ATSDR postpone making formal conclusions about the public health significance of atmospheric releases of uranium from the Y-12 facility at Oak Ridge without first considering the magnitude and uncertainty of the cumulative exposure to other sources of radiation released from the Oak Ridge Reservation or deposited in the Oak Ridge region during the same period of time.

As mentioned several times (e.g., pages 2 and 31), this PHA evaluates community health concerns and issues associated with the uranium releases from the Y-12 plant. However, ATSDR noted on pages 68 and 82 that the fossil fuel plants (such as coal burning plants) could impact the uranium analyses performed in Oak Ridge. The uranium analysis of Scarboro soil sampling and the ORR air monitoring would have included all other possible sources of uranium in the Oak Ridge area. In addition, ATSDR scientists will also conduct PHAs on the following releases and issues: 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, PCBs released from all three facilities, and off-site groundwater. ATSDR is also screening current (1990 to 2003) environmental data to determine whether additional chemicals will require further evaluation.

After all the individual assessments have been completed, ATSDR will evaluate cumulative exposures from significant sources of radiation at the ORR.

75

The document seriously underestimates the problems with releases and exposures at Oak Ridge, and indeed, does not even mention most of these problems. It needs to take account of the documented problems at U.S. nuclear facilities as detailed in US OTA 1991; US GAO 1998, 1999; US Congress 1994, 1998, 1999. Much of the document is at odds with these earlier reports, which are extraordinarily well documented.

There are gaps in the uranium release estimates.

The pertinent background information is that Y-12 has processed larger quantities of depleted uranium than enriched uranium under conditions that quite probably favored its release relative to enriched uranium. This makes any assumptions about the character of the release stream highly speculative.

The document has not accounted for the environmental fate of the bulk of uranium released from Y-12.

As noted on page 49, the Task 6 team independently evaluated past Y-12 airborne uranium releases and generated release estimates much higher than those previously reported by DOE (see Figure 13 and Table 5). From pages 2-7 to 2-15, the Task 6 team describes how the Y-12 air release estimates were derived. As stated on page 2-12 in the Task 6 report, "To estimate releases for those periods for which monitoring data or reported releases were not found, Task 6 investigators used production data and release estimates for adjacent years. Production data for an unmonitored period was compared to production data for adjacent time periods for which release estimates were available. Release estimates for the unmonitored period were then calculated based on the differences in production data for the two time periods." They attributed the difference to DOE's use of incomplete sets of effluent monitoring data and release documents, along with their use of release estimates based on effluent monitoring data not adequately corrected to account for sampling biases (ChemRisk 1999).

While the simultaneous release of depleted, normal, and enriched uranium makes the emission of specific isotopes difficult, it does not change the conclusion that the total effect was low.

The total uranium release estimate calculated by the Task 6 team are over seven times higher than the release totals reported by DOE (ChemRisk 1999; see Figure 13). Some individual years are as much as 140 times higher than the original DOE estimates. The evaluation of past exposures is based on the higher Task 6 estimates.

76

The document has not accounted for the exposures of individuals and populations who are, as yet unidentified.

I would recommend that ATSDR postpone making formal conclusions about the public health significance of atmospheric releases of uranium from the Y-12 facility at Oak Ridge without first considering the number of persons exposed.

The Scarboro community is used as a reference location because it represents an established community adjacent to the ORR where residents resided during the years of uranium releases. Consequently, if the Scarboro community–the population likely to have received the highest uranium exposures from the Y-12 plant–was not in the past and is not currently being exposed to harmful levels of uranium from the Y-12 plant, then other residents living near the Y-12 plant, including those within the city of Oak Ridge, are also not being exposed to harmful levels of uranium.

As stated in the title, the Task 6 report was a "Screening Evaluation of Potential Off-Site Exposure." Since the screening evaluation, which contained conservative aspects (see list of conservative aspects of the screening evaluation on pages 48 and 92 of the PHA), resulted in a total past uranium dose below levels of health concern, ATSDR does not believe it is necessary to conduct further evaluation or identify the number of people exposed.

Discussion of Multiple Chemical and Pathway Exposures

77

Will the dose from thorium releases also be estimated?

No. Thorium was evaluated during the Dose Reconstruction Feasibility Study, which was an initial screening that determined which chemicals required further evaluation (ChemRisk 1993b). In short, screening calculations were conducted to rank the chemicals and radionuclides with respect to their potential to cause harmful health effects. Based on the ranking, four substances were identified as high priority chemicals for further study (radioactive iodine, radioactive cesium, mercury, and PCBs). Thorium was not identified as a high priority chemical for further study based on the relative magnitude of potential hazard. See the Oak Ridge Health Studies Phase I Reports on the Project-CD entitled, "The Oak Ridge Health Agreement Studies, Oak Ridge Dose Reconstruction."

78

A proper health assessment for a community close to Y-12, like Scarboro, [or for Oak Ridge] should mention all the sources of particulate's and chemicals that form long term insoluble particles in the body. The problems from Scarboro stem from the practice of emitting uranium oxide dusts and many other metal oxides dusts from not only Y-12, but the other DOE plants and the highly polluting TVA systems that power them. The burning of PCB cutting oils and DU at the Y-12 burn yard and the formation of uranium oxides and dioxin products also affected Scarboro. Toxic metals, fluorides, and dioxin are known to damage cell mitochondria.

In 1998 and 2001, FAMU and EPA Region IV, respectively, collected soil, sediment, and surface water samples from the Scarboro community (FAMU 1998; EPA 2003). All FAMU samples were analyzed for mercury, gross alpha/beta content, uranium, and gamma emitting radionuclides. About 10% of the FAMU samples were also analyzed for target compound list organics, target analyte list inorganics, strontium 90, uranium, thorium, and plutonium. All EPA Region IV samples were subjected to a full analytical scan, including inorganic metals, volatile organic compounds, semi-volatile organic compounds, radiochemicals, organochlorine pesticides, and PCBs. The EPA Region IV report concluded that "there is not an elevation of chemical, metal, or radionuclides above a regulatory health level of concern... the Scarboro community is not currently being exposed to substances from the Y-12 facility in quantities that pose an unreasonable risk to health or the environment... the Scarboro community is safe" (EPA 2003). ATSDR also evaluated the environmental sampling data in Scarboro (FAMU and EPA) and determined that none of the soil, sediment, or surface water samples collected from the Scarboro community contained chemicals at levels of health concern.

As mentioned several times (e.g., pages 2 and 31), this PHA evaluates community health concerns and issues associated with the uranium releases from the Y-12 plant. The release and exposure to other contaminants of concern are not addressed in this document. ATSDR scientists will conduct additional PHAs on the following releases and issues: K-25 releases of fluorides and uranium, Y-12 releases of mercury, X-10 release of iodine-131, X-10 release of radionuclides from White Oak Creek, PCBs released from all three facilities, releases from the TSCA incinerator, and off-site groundwater. ATSDR is also screening current (1990 to 2003) environmental data to determine whether additional chemicals will require further evaluation.

79

ATSDR has not accounted for the total doses and risks from all pathways, bonined for all ages, and across all lifetimes. Its estimates are massively incomplete.

ATSDR evaluated past and current lifetime exposures to uranium through multiple pathways. The total past uranium dose across all media (see Tables 7, 9, and 10) is presented in Table 4 and discussed on pages 43–65. The current uranium dose from inhalation of the air, ingestion of soil, and ingestion of vegetables is summed in Table 14 and discussed on pages 66–87.

Quantitative Risk Assessment and Uncertainty/Sensitivity Analyses

80

The lack of a quantitative risk assessment associated in the PHA is another example of ATSDR's flat refusal to incorporate community concerns. In line with aforementioned observations about ATSDR selectively refusing to address multiple contaminants and risk assessment is the added fact that ATSDR selectively refused to incorporate neither a quantitative risk evaluation resulting from cumulative exposures to similar types of contaminants during similar time periods, nor has it carried out a quantitative uncertainty and sensitivity analysis, processes that have been integral to all previous dose reconstruction studies at DOE facilities. Once more these fall in contrast to release and risk analysis from weapons production e.g. the NCI-131 calculator that provides both dose and risk assessments for concerned individuals.

As explained in Section 2 of ATSDR's Public Health Assessment Guidance Manual (http://www.atsdr.cdc.gov/HAC/HAGM/) and in A Citizen's Guide to Risk Assessments and Public Health Assessments at Contaminated Sites (written jointly by ATSDR and EPA Region IV), there are deliberate differences between ATSDR's health assessments and EPA's risk assessments. The two agencies have distinct purposes that necessitate different goals for their assessments. An EPA risk assessment is used to support the selection of a remedial measure at a site. An ATSDR health assessment is a mechanism to provide the community with information on the public health implications of a specific site, identifying those populations for which further health actions or studies are needed. See the response to comment 127 for additional information distinguishing a risk assessment from a health assessment.

Following the ATSDR Cancer Framework Policy, ATSDR does not perform risk assessments. The agency, however, does recognize the importance of EPA risk assessment and risk analysis to determine if levels of chemicals at hazardous waste sites pose an unacceptable risk as defined by regulatory standards and requirements and to help regulatory officials make decisions in support of cleanup strategies that will ensure overall protection of human health and the environment. ATSDR acknowledges that conservative safety margins are built into EPA risk assessments and that these assessments do not measure the actual health effects that hazardous chemicals at a site have on people.

Current ATSDR policy does not allow for the use of risk coefficients in determining the impact on public health. The issue with applying a "quantitative" risk coefficient to any dose is that one can calculate any risk and this is "perceived" as a true value. As stated in the ATSDR Cancer Framework Policy, "this artificial appearance of precision can lead decision makers to rely heavily on numerical risk estimates. Although ATSDR recognizes the utility of numerical risk estimates in risk analysis, the Agency considers these estimates in the context of the variables and assumptions involved in their derivation and in the broader context of biomedical opinion, host factors, and actual exposure conditions." The agency acknowledges that, at present, no single generally applicable procedure for exposure assessment exists, and, therefore, exposures to carcinogens must be assessed on a case-by-case or context-specific basis.

For additional information, please review the framework policy that can be found at http://www.atsdr.cdc.gov/cancer.html.

Please see the response to comment 81 for a discussion about conducting uncertainty and sensitivity analyses.

81

The document employs massively inadequate risk-assessment methodology, in large part because it is full of subjective guesses and estimates, employs no uncertainty analyses, and does no sensitivity analysis. All three failures are contrary to standard best risk-assessment practice and all three problems are specifically noted as ones to be avoided in the 1996 classic National Academy of Sciences document, Science and Judgment in Risk Assessment.

This issue of conducting an uncertainty analysis was raised by an ORRHES member at the April 22, 2003 meeting and addressed by ATSDR in a written response provided to ORRHES at the June 2, 2003 meeting. The following provides details from ATSDR's response:

As discussed in the NCRP Commentary 14, A Guide for Uncertainty Analysis in Dose and Risk Assessments Related To Environmental Contamination, issued in 1996, if a conservatively based screening calculation is performed and this screening calculation indicates the risk is "clearly below regulatory or risk levels of concern," and the possible exposure is low, then a quantitative uncertainty analysis may not be necessary. By design, conservative screenings are "highly unlikely to underestimate the true dose or risk."

This issue of uncertainty analyses and sensitivity analysis was evaluated by the Task 6 team, ATSDR's technical reviewers, and ATSDR scientists.

As stated in the title, the Task 6 report was a "Screening Evaluation of Potential Off-Site Exposure," that routinely and appropriately used several layers of conservatism and protective assumptions and approaches in estimating concentrations and doses. Task 6 report states "some level of conservatism was maintained in the uranium concentration estimates used in Level II screening to ensure that hazards to a significant portion of the potentially exposed population were not underestimated" (page ES-9). Also, the Task 6 report states on page 2-13 that a level of conservatism was added by combining the uranium activity amounts for U 234 and U 235 and that this approach is considered reasonable for this screening assessment since the Task 6 estimates do not include a formal uncertainty analysis. On page D-3, the Task 6 authors state "although an uncertainty analysis of the Task 6 air source term was not within the scope of Task 6, experts interviewed during the project consider release estimates for enriched uranium to be suitable for the Task 6 screening assessment and are within an order of magnitude of actual releases" (ChemRisk 1999). The authors also state (on page 5-2) that based on the project team's experience in the Dose Reconstructions Feasibility Study and the Task 6 screening evaluation they identified areas they believe are significant contributors of the overall uncertainty of the results of the Task 6 screening evaluation. The authors state that "these areas should be examined if the evaluation of Oak Ridge uranium releases is to proceed beyond the conservative screening stage and on to nonconservative screening and possibly a stage of refined evaluation that would likely include uncertainty and sensitivity analyses to assist in the decision making process" (ChemRisk 1999).

Also, the internationally recognized expert technical reviewers hired by ATSDR to review the Task 6 report pointed out that the report is somewhat lacking in uncertainty and sensitivity analysis. However, "the estimates made in the report tend to be on the conservative side–one expects, therefore, that (when in error) the report would tend to overestimate the extent to which exposure to uranium is a problem in the Oak Ridge area. Further refinements to the study are likely to reveal that uranium exposures are actually lower than those currently estimated." Also, the technical reviewers stated the report is technically sound and applicable to decision-making (see page G-7 of the PHA).

ATSDR scientists also identified other aspects of the Task 6 report that resulted in several additional layers of conservatism and protective assumptions and approaches (see list of conservative aspects of the screening evaluation on pages 48 and 92 of the PHA). Since the Task 6 screening evaluation of air, soil, and surface water pathways resulted in a total past uranium radiation CEDE (155 mrem over 70 years) well below (32 times less than) the ATSDR radiogenic cancer comparison value (5000 mrem over 70 years), ATSDR does not believe the evaluation of Y-12 uranium releases requires a further nonconservative screening or a refined evaluation with uncertainty and sensitivity analyses.

In addition, the total past uranium radiation CEDE (155 mrem over 70 years) is also less than the average annual background radiation dose received by individuals living in Denver or the radiation dose an individual would receive during a computed tomography (CT) scan (1,000 mrem/scan) at a local hospital (see Figure 12). As shown in Table 15, ATSDR also calculated a radiological dose to the lung following the inhalation of uranium. This dose is not considered a dose of public health concern. Even using the conservative overestimated doses, people in the Scarboro community (as well as the Oak Ridge community) were not exposed to levels of uranium that are above levels of health concern.

Additionally, the following is a list of conservative aspect of the screening evaluation that resulted in the overestimated doses.

1. The Task 6 report noted that the Y-12 uranium releases for some of the years may have been understated due to omission of some unmonitored release estimates. This would cause the empirical c/Q values (used in the air dispersion model) to be overestimated and in turn would cause the air concentrations to be overestimated.



2. The majority of the total uranium radiation dose is attributed to frequently eating fish from the EFPC and eating vegetables grown in contaminated soil over several years. If a person did not regularly eat fish from the creek or homegrown vegetables over a prolonged period of time (which is very probable), then that person's uranium dose would likely have been substantially lower than the estimated doses reported in this PHA.



3. According to ATSDR's regression analysis, the method that the Task 6 team used to estimate historical uranium air concentrations overestimated uranium 234/235 concentrations by as much as a factor of 5. Consequently, airborne uranium 234/235 doses based on this method were most likely overestimated.



4. In evaluating the soil exposure pathway, the Task 6 team used EFPC floodplain soil data to calculate doses instead of Scarboro soil. Actual measured uranium concentrations in Scarboro soil are much lower than the uranium concentrations in the floodplain soil. The estimated doses would be much lower if they were based on actual measured concentrations in Scarboro.

As explained in Section 2 of ATSDR's Public Health Assessment Guidance Manual (http://www.atsdr.cdc.gov/HAC/HAGM/) and in A Citizen's Guide to Risk Assessments and Public Health Assessments at Contaminated Sites (written jointly by ATSDR and EPA Region IV), there are deliberate differences between ATSDR's health assessments and EPA's risk assessments. The two agencies have distinctly different purposes that necessitate different goals for their assessments. A risk assessment is used to support the selection of a remedial measure at a site. An ATSDR health assessment is a mechanism to provide the community with information on the public health implications of a specific site, identifying those populations for which further health actions or studies are needed. See the response to comment 127 for additional information distinguishing a risk assessment from a health assessment.

Data and Modeling

82

The Summary should contain a paragraph listing the many types and sources of data that contribute to the estimation of uranium level around INCLUDING the sources that confirm the low levels by the absence of detection. (P8)

Thank you for the comment. The sources have been added to the summary in the final PHA.

83

ATSDR has not provided all the data sets used.

The original EPA data is not included making verification very doubtful. (p84-88)

It is not ATSDR's policy to provide raw data from primary sources that are publicly available. But ATSDR does supply references to the data used; which is good technical practice.

The past exposure evaluation primarily relied on data provided in the Task 6 report (ChemRisk 1999), which is available at the following Web site: http://www2.state.tn.us/health/CEDS/OakRidge/ORidge.html .

The current exposure evaluation primarily relied on data supplied by OREIS, a centralized, standardized, quality-assured, and configuration-controlled environmental data management system. It is a public data source available at the following Web site http://www-oreis.bechteljacobs.org/oreis/help/oreishome.html . ATSDR also supplemented the current exposure pathway with data from FAMU (1998) and EPA Region IV (2003). The FAMU data are available in OREIS. EPA Region IV's final report is available at the following Web site: http://www.epa.gov/Region4/waste/fedfac/doeorr.htm .

All DOE sources are available at the DOE Information Center (475 Oak Ridge Turnpike, Oak Ridge TN 37830; phone: 865-241-4780; Web site: http://www.oakridge.doe.gov/info_cntr/index.html ).

84

This entire section dwells on the EPA data and neglects the FAMU data which is more complete. (p84-88)

ATSDR focused the majority of the uranium enrichment evaluation using the EPA Region IV data because the FAMU data did not include isotopic analysis for U 234. The EPA Region IV and FAMU data did not differ significantly. However, the FAMU averages are included in Figures 24 and 25.

85

Please specify which modeling program(s) was used to estimate radiation exposure.

Will the modeling program information be made available for review?

As mentioned in the PHA, ATSDR selected appropriate exposure parameters and values from EPA's Exposure Factors Handbook (EPA 1997). The equations used for the estimation of radiation exposure were those used in other types of assessments as well as those used in the Task 6 Report. ATSDR estimated the radiation dose and used the ICRP database of dose coefficients to estimate the CEDEs. The ICRP dose coefficients are copyrighted and can be obtained through many university and technical libraries. They are also available from the following Web site: http://www.icrp.org/ .

86

The public comment section of the ATSDR uranium report includes some of my comments on Oak Ridge releases, but totally omits my comments on the fluorides effect on Oak Ridge and the principle health mechanism. This appears fraudulent in nature to omit a principle mechanism for uranium and metal oxides effects on the immune system. The principle mechanism, which I have told in public meetings and even the local newspaper, points out the migration of metals and fluorides into the lymph nodes. This triggering cytokine's that set off Th-1 type inflammation and in the long term, the leading to Th-2 mode and IL-10 dominated effects that shut down macrophage actions. Since I have made this very public and told [ATSDR staff] this directly, I can only assume he is intent on covering up the real health problems in Oak Ridge and needs to be removed from this project. It is inexcusable to not report this in the "Public Comment" section of the report.

As mentioned several times (e.g., pages 2 and 31), this PHA evaluates community health concerns and issues associated with the uranium releases from the Y-12 plant. Community concerns related to the release and exposures to other contaminants of concern are not addressed in this document. The commenter's community health concerns about fluorides will be addressed in a separate PHA that evaluates exposure to fluorides and uranium released from the K-25 facility.

ATSDR scientists will conduct additional PHAs on the following releases and issues: Y-12 releases of mercury, X-10 release of iodine-131, X-10 release of radionuclides from White Oak Creek, PCBs released from all three facilities, releases from the TSCA incinerator, and off-site groundwater. ATSDR is also screening current (1990 to 2003) environmental data to determine whether additional chemicals will require further evaluation.

87

Expand the response to indicate that fly overs have revealed the presence of relatively small amounts of contaminant, i.e., several Clinch River Cs137 hot spots at one half the action level by measurement, and Chattanooga shale outcrop on East Fork Ridge containing natural uranium. The method does more than detect large releases. (P128)

Thank you for the additional information, which has been added to the final PHA.

88

[ATSDR staff] and I also talked on June 5 about the potential value of writing a booklet to explain the various criteria being used for environmental protection and health assessments, and the deliberately chosen margins that exist between them. Such a booklet would be a valuable reference for people reading the PHA reports.

There are several ATSDR resources already available to the public that explain ATSDR's health assessment process:

• An interactive program that provides an overview of the public health assessment process ATSDR uses to evaluate whether people will be harmed by hazardous materials is available at: http://www.atsdr.cdc.gov/training/public-health-assessment-overview/html/index.html.



• ATSDR's Public Health Assessment Guidance Manual, which outlines the health assessment process, is available at: http://www.atsdr.cdc.gov/HAC/HAGM/).



• Appendix A of ATSDR's chemical-specific Toxicological Profiles discuss the derivation of the each of the MRLs. These profiles are available at: http://www.atsdr.cdc.gov/toxpro2.html#-T-.

89

There is a wealth of valuable information contained in the appendices of the PHA, but the table of contents of the PHA does not list the titles of the appendices. This gives the impression that the appendices are not considered important (but they are) and that perhaps ATSDR would rather no have people to study them (which was probably not ATSDR's intent). It is therefore suggested that the appendices be listed in the table of contents, including the sub-parts of Appendix G.

A list of appendices, including their titles, is included on page vi.

90

While the Lower East Fork Poplar Creek was being remediated for mercury, sections were also remediated for uranium. This seems relevant to this report. (p. 14, lines 11 - 23)

Thank you for the additional information, which has been added to the final PHA.

91

The clean-up of Boneyard/Burnyard is complete with the waste buried in the EMWMF. (p. 14, lines 25 - 30)

Thank you for the additional information, which has been added to the final PHA.

92

Another former name for ETTP is the Oak Ridge Gaseous Diffusion Plant. (p. 15, line 11)

Thank you for the additional information, which has been added to the final PHA.

93

Uranium was also processed for use in commercial nuclear reactors. (p. 11, line 4)

Thank you for the additional information, which has been added to the final PHA.

94

It is not clear in this section that deer hunts are held on the Oak Ridge Reservation, in which case the deer are monitored for radiation prior to being released to the hunter. (p. 16, lines 13 - 17)

The text has been clarified in the final PHA.

95

What is the reference for the EPA CERCLA cleanup level of 15 mrem/yr?

EPA. 1997. Establishment of Cleanup Levels for CERCLA Sites with Radioactive Contamination. Memorandum from Stephen Luftig, Director of the Office of Emergency and Remedial Response, and Larry Weinstock, Acting Director of the Office of Radiation and Indoor Air. August 22, 1997. OSWER No. 9200. 4-18.

96

The [organization] is a non-profit regional organization funded by the state of Tennessee and established to provide local government and citizen input into the environmental management, decision-making and operation of the DOE's Oak Ridge Reservation. The Board of Directors is composed of elected and appointed officials from the City of Oak Ridge and the seven counties surrounding and downstream of the ORR, and the chair of the Citizen's Advisory Panel. The [organization] is a stakeholder organization with up to 20 members with diverse backgrounds who represent the greater ORR region; the [organization] supports Board interests by reviewing and providing recommendations on DOE decisions and policies.

The [organization] appreciates the opportunity to comment on ATSDR's PHA for Y-12 Uranium Releases.

You are welcome. ATSDR appreciates receiving comments from community members, civic organizations, and other government agencies interested in the public health activities at the ORR.

97

The charge of HHS and ATSDR is for public health protection and the piece-meal approach to a serious problem in Oak Ridge is not in the public's interest. ATSDR has a well established record of not implementing effective studies designed to get to the root of health problems and this current Y-12 uranium report and the techniques of [ATSDR staff] is one more prime example.

As noted in the response to comment 66, ATSDR is the lead public health agency for implementing the health-related provisions of CERCLA and is charged under the Superfund Act to assess the presence and nature of health hazards at specific Superfund sites, help reduce or prevent further exposure, and expand the knowledge base about health effects related to exposure to hazardous substances (as noted in the response to community concern #9).

ATSDR scientists followed the guidance set forth in the Public Health Assessment Guidance Manual (available at the following Web site: http://www.atsdr.cdc.gov/HAC/HAGM/). The manual is a guidance document for health assessors both at ATSDR and in the states. It outlines the health assessment process and provides information to the health assessors on different technical and scientific aspects of performing PHAs. The Public Health Assessment Guidance Manual is the result of the combined efforts of ATSDR, Oak Ridge National Laboratory, and state health departments participating in the ATSDR Public Health Assessment Cooperative Agreement Program. The draft manual was made available for public comment through an announcement in the Federal Register and distributed to federal, state, and local entities, private consultants and corporations, and trade/professional organizations.

ATSDR scientists will conduct additional PHAs on the following releases and issues: K-25 releases of fluorides and uranium, Y-12 releases of mercury, X-10 release of iodine-131, X-10 release of radionuclides from White Oak Creek, PCBs released from all three facilities, releases from the TSCA incinerator, and off-site groundwater. ATSDR is also screening current (1990 to 2003) environmental data to determine whether additional chemicals will require further evaluation. ATSDR decided to release each PHA as it is completed to be most responsive in addressing the community's concerns.

98

[Organization] believes this study is dangerously defective. [Organization] members desire only that the best science be imparted to such an important endeavor. At present we see no evidence of such by ATSDR.

As noted in the response to comment 97, this PHA follows guidance set forth by the Agency in the Public Health Assessment Guidance Manual. ATSDR is committed to updating the Public Health Assessment Guidance Manual as new technical information becomes available. The Agency welcomes comments from users of the manual. If there is a weakness in the methods and techniques employed during this PHA, please provide specific comments to the Agency, so that these issues can be addressed.

In addition, the Y-12 Uranium Releases PHA underwent internal ATSDR review and an external peer review. All peer reviewers approved of the assessment and found no major flaws that would invalidate ATSDR conclusions and recommendations. In the words of one peer reviewer: "the assessment is very well done, clearly characterized and summarized. I could find no errors of fact of logic, nor were assumptions inappropriate or unrealistic."

99

We haven't found Osama, we haven't found Saddam, or his sons. We haven't found solid evidence of the weapons of mass destruction. And there does seem to be a search on for these men and weapons. But we also cannot find evidence that uranium releases from Y-12 caused health problems in the adjoining community, not now, not ever, according to the Agency for Toxic Substances and Disease Registry. None? Not ever? 5,920 claims have been filed for compensation due to radiation-induced cancers under the Energy Employees Occupational Illness Compensation Plan Act at Oak Ridge Operations alone. A large number were from Y-12. Are we supposed to assume that the "rad gremlins" know their place, and will not dare pass outside the plant's boundaries? With the proper spin on results of studies, the number may look low, but I find it irrational to qualitatively state that no harm at all has come to the community.

ATSDR's PHAs are evaluations of exposures to off-site populations. This PHA addresses community health concerns and issues associated with past and current uranium releases from the Y-12 plant. It is not an evaluation of people who were exposed while working on-site at the Y-12 plant. This responsibility is assigned to other agencies.

ATSDR evaluated past and current off-site exposures to uranium contamination released from the Y-12 plant and found that the levels of uranium that people were exposed to (off-site) are not at levels expected to cause adverse radiation or chemical health effects. The conclusion of no apparent public health hazard for people living near the Y-12 plant is based on a conservative screening evaluation that did not underestimate the level of exposure (see list of conservative aspects on pages 48 and 92 of the PHA).

100

The document is seriously scientifically flawed in 3 major ways, as well as in 7 additional ways, and is an embarrassment to the U.S. government, to science, and to ATSDR. This document must be massively improved, prior to publication, or it will engender massive scientific criticism.

As noted in the response to comment 97, ATSDR scientists followed the guidance set forth in the Public Health Assessment Guidance Manual (available at the following Web site: http://www.atsdr.cdc.gov/HAC/HAGM/). The draft manual was made available for public comment through an announcement in the Federal Register and distributed to federal, state, and local entities, private consultants and corporations, and trade/professional organizations.

On numerous occasions, the procedures and methods used in the PHA have been presented to the PHAWG and ORRHES, which include technical scientists from the Oak Ridge community. As noted in the response to comment 102, the PHAWG and ORRHES have provided many useful recommendations and discussions to ATSDR and their comments have been very helpful in improving the document. See Figure 5 for opportunities for the public to provide input into the ATSDR PHAs on the ORR.

Additionally, the Y-12 Uranium Releases PHA underwent internal ATSDR review and an external peer review. All peer reviewers approved of the assessment and found no major flaws that would invalidate ATSDR conclusions and recommendations. In the words of one peer reviewer: "the assessment is very well done, clearly characterized and summarized. I could find no errors of fact of logic, nor were assumptions inappropriate or unrealistic."

Throughout this process, ATSDR, ORRHES, and PHAWG have not identified a scientific flaw or technical challenge that would change our conclusions or warrant any further evaluation or study.

101

The ATSDR has failed in its radiation-dose calculations in the past, and I have carefully reviewed, line by line, at least two such examples of shoddy science. This appears to be the same.

ATSDR stands by the radiation dose calculations in this PHA. Without more specifics, ATSDR cannot respond further.