Oak Ridge Reservation: Exposure Evaluation Work Group

PExposure Evaluation Work Group

April 11, 2005 - Meeting Minutes

Attendance

ORRHES Members attending:
Tony Malinauskas (Chair), David Johnson, and Jeff Hill

Public Members attending:
John Merkle

ATSDR Staff attending:
Loretta Bush (phone), Jack Hanley (phone), Marilyn Horton (phone), and Bill Taylor

ERG Contractors attending:
Liz Bertelsen (phone)

Purpose

Dr. Malinauskas called the meeting to order at 5:30 p.m. The purpose of the meeting was to review and approve EEWG recommendations to ORRHES concerning the Agency for Toxic Substances and Disease Registry's (ATSDR) Toxic Substances Control Act (TSCA) Incinerator Public Health Assessment (PHA).

Dr. Malinauskas asked for comments on the meeting minutes from March 21, 2005. No comments were noted and the minutes were approved.

ORRHES Recommendations Concerning the TSCA PHA

Dr. Malinauskas explained that two recommendations were prepared for the EEWG to approve and forward to the ORRHES for its approval and submittal to ATSDR.

• Recommendation #1: ORRHES recommends that ATSDR resolve the ORRHES comments on the TSCA PHA.



• Recommendation #2: ORRHES recommends that the ATSDR issue the TSCA PHA after the ORRHES comments have been resolved satisfactorily.

ORRHES Comments on the PHA for the Oak Ridge Reservation (ORR) TSCA Incinerator
Dr. Malinauskas presented one general comment and 28 specific comments that had been received on the PHA. The EEWG read through these, but did not review the editorial comments (11, 14, 17, and 24) during the meeting. The list of comments is presented verbatim below, followed by discussions on particular comments.

General Comment
The document is well written and, in large measure, should be comprehendible to the lay public. This is partly borne out by the sparse amount of comments that have been made by members of the Exposure Evaluation Work Group and the ORRHES.

Specific Comments

1. P. 10. This section should give some description of the composition of the feedstock (instead of on p. 14) as well as the composition of the incinerator effluents (e.g., water, carbon and nitrogen oxides, chloro compounds, etc.). Also, the fate of the noxious effluents should be addressed more completely here (it is partially covered on p.12). In other words, put both descriptions in the same place.



2. P. 10. State that the ventilated table on which repackaging occurs is ventilated through a filtration system that prevents particulates and noxious gases from entering the atmosphere (if this is indeed correct).



3. P. 12 (and P. 22). The stack of the TSCA incinerator is 100 feet high. The parallel, bounding ridges are 200 feet high, twice as high as the incinerator stack. Has this been considered in the dispersion calculations? How does this affect dispersion?



4. P. 22 (and Fig. 6). Describe the Wind Rose in greater detail and clarity. For example, note that the circular grid lines represent the percent of time that the wind blows in a particular direction, and that the wind direction is from the end of the bar towards the center of the Wind Rose. Also, reword the sentence on p. 22 to something like "As Fig. 6 depicts, the prevailing wind patterns near the TSCA incinerator are from the general southwest direction (i.e., WSW, SW, and SSW) toward the northeast and, to a lesser extent, from the general northeast direction toward the southwest."



5. P. 30. Have you sought input from the Knox County Health Department in your presentation of the air quality of the Greater Knoxville area? This certainly would demonstrate a desire to work openly with a broad range of stakeholders.



6. P. 31. Have incinerator campaigns been conducted during periods of high pollen concentration? If so, what effect would this have on the dispersion of airborne material?



7. P. 39. Refer the reader to the definition of "Comparison Value" on p. E-2 in the appropriate paragraph. Also, the definition of CV needs to be more specific. Is it wrong to state that the CV is intended to be lower than the lowest value known to be associated with adverse health effects by at least (a stated factor) of safety?



8. P. 52 (and P. C-14). Despite the difference in the limits of detection of the analytical methods used by TDEC and DOE, the TDEC monitoring data should be considered when selecting contaminants for further consideration. For beryllium, for example, the TDEC value is equal to the comparison value. Also, is limit of detection actually intended, as opposed to precision (i.e., the number of significant figures to which the results may be determined)?



9. P. 52 (and Pp. 53 and 58). There appear to be several instances in which the terms "sampling" and "monitoring" are used interchangeably. "Sampling" implies selecting a portion of the whole for analysis, whereas "monitoring" implies continuously measuring the whole. Also, the terms "continuous sampling" and "sampling continuously" are misleading, and should be replaced with "frequent sampling" or "samples taken at regular intervals."



10. P. 54. If possible, indicate wind speed and direction at the times of the TRV events.



11. P. 59. We suggest re-wording line 13 to read "...deliberately conservative health-based comparison values.



12. P.59 (and Pp. 61, 62, and 64). Attributing a difference between calculated and measured concentrations to one or more causes requires explicit consideration of the accuracy of the calculations. This is particularly true of air-dispersion calculations, so that the perceived five-fold difference may very well be within the uncertainty of the calculation, although the occurrence of sources other than the TSCA incinerator is also a plausible contributing factor.



13. P. 60 (and P. B-4). ATSDR should employ a consistent terminology for health effect concentration limits. In the PHA for uranium releases from Y-12, the term "lowest observed adverse effect level" (LOAEL) is used. In the Y-12 report, the non-cancer LOAEL is approximately 0.7 micrograms per cubic meter, and the cancer-related LOAEL is 50 micrograms per cubic meter. In Table B-1 on p. B-4, the comparison value for arsenic is given as 2x10^-4 micrograms per cubic meter. This value is lower than the non-cancer LOAEL by a factor of 250,000. The definition of LOAEL should be given, as well as the relationship between LOAEL and CV, if only for the sake of consistency.



14. P. 60. Line 30 should read "...highest annual average exposure..."



15. Pp. 60 – 63 (and Pp. B-4 and D-1). The comparison values for arsenic, cadmium, and chromium are 1250- to 500,000-times smaller than the corresponding LOAEL values. Why are the differences so large, and so variable? And what is the relationship of both the LOAEL and the CV to the CREG, that is defined on P. D-1?



16. P. 66. Lines 21 – 26 indicate that several reports that are identified are available for reading in the ATSDR Oak Ridge Field Office. Is this correct?



17. P. B-1. We suggest the following editorial changes:

• Line 4: "...validated sampling data, where available..."
• Line 12: "...actual environmental or topographic conditions..."
• Lines 20 and 32: "...concentrations at ground level..."

Pp. B-2 to B-3. It would be helpful to list the quantities required as input to the ISCST code, and to discuss the uncertainties associated with each one. Also, it would be helpful to cite the EPA User Manual for the ISCST code for those who might wish to pursue this facet further.

P. B-2. Consider providing a set of maps depicting contours of calculated ground level concentrations of contaminants of concern. This might help in providing a visual description of the effects of wind-rose data, stack height, and topography.

Pp. B-4 and B-5. The report of the Tennessee Governor's independent panel (Iglar 1998) should be cited in the text of Appendix B.

P. B-5. The EPA Clean Air Assessment (CAP-88) document does not appear to be cited in the list of references. It is available on-line at www.epa.gov/radiation/assessment/CAP88/.

P. B-7. Knowing that air dispersion calculations do not yield precise values because of theoretical and empirical limitations on the calculations as well as uncertainties associated with the input parameters, it would nonetheless be instructive to compare the calculated ground-level concentrations with reliable measured values for particulate matter, radionuclides, and metals, where the latter are available, instead of dismissing the calculations completely.

P. B-7. It is not obvious that the same dispersion factor can be used for all of the contaminants that have been examined. Justification of this assumption is required.

P. B-8. Line 4: "...by the fact that..."

P. B-8 (and C-6). The statement that dioxins and furans are the air contaminants of greatest concern for incineration facilities seems to contradict the statement on P. C-6, based on Table C-2, that the maximum annual measured air concentrations at ground level of arsenic, cadmium, and chromium exceeded their respective comparison values.

P. B-9. Is the report (EPA 1998) available at the DOE Information Center?

P. C-13. The statement that only arsenic and chromium had at least one measured concentration greater than their health-based comparison values is not exactly correct, as Table C-5 indicates that the highest measured value of beryllium was equal to its CV. Also, it would be helpful to include the uncertainties associated with these measured values.

There are four sets of parameters that are pertinent to this report for arsenic, cadmium, chromium, and beryllium. They are the CV numbers, calculated concentrations, LOAEL values, and measured maximum and long-term concentrations. A table that allows a comparison to be made of the four sets of values would be most instructive.

Discussion on Comments

Specific Comment 6: Mr. Merkle asked about interactions at the surface. Dr. Taylor said that this would be possible.

Specific Comment 7: Mr. Merkle noted that safety factors vary. Dr. Taylor said that ATSDR has different comparison values (CVs). Mr. Merkle inquired whether Cancer Risk Evaluation Guides (CREGs) were used for metals. Dr. Taylor replied that this depended on the toxicity of the metals and the available evidence. Dr. Malinauskas suggested clarifying this in the PHA.

Mr. Merkle stated his belief that the public would be interested in information on ATSDR's lowest-observed-adverse-effect level (LOAEL).

Specific Comment 8: Mr. Merkle suggested clarifying limits of detection. Dr. Malinauskas noted that a lower concentration might not be detectable. Mr. Merkle recommended that ATSDR define the limits.

Specific Comment 12: Dr. Malinauskas expressed concern about the accuracy of the calculations. Mr. Merkle indicated that the calculations were not expected to be completely accurate, but had a mathematical basis.

Specific Comment 13: Dr. Malinauskas suggested clarifying and explaining the various health-based CVs in the PHA.

Specific Comment 16: Dr. Malinauskas asked Dr. Taylor to ensure that these reports are in the field office.

Specific Comment 18: Dr. Malinauskas indicated that a description of the Industrial Source Complex Short Term (ISCST) code was available on the Internet, and Mr. Merkle had provided the Web site address to be included in the PHA.

Specific Comment 20: After group discussion, it was determined that this comment should be removed.

Specific Comment 22: Dr. Taylor requested clarification on the phrase "dismissing the calculations." Mr. Merkle suggested including comparisons of the calculations to ensure their accuracy. Dr. Taylor replied that these data were possibly unavailable. Mr. Merkle recommended that ATSDR make additional comparisons if the data were available.

Specific Comment 25: Dr. Taylor said that the first part of this comment referred to incineration facilities in general, and the second portion referred to actual measurements from monitoring stations that exceeded ATSDR's health-based CVs. Mr. Hanley noted that Dr. Taylor's comments were accurate and indicated that this would be clarified in the PHA.

Specific Comment 27: Mr. Merkle expressed his concern that this indicated ATSDR believed the U.S. Department of Energy (DOE's) findings. Dr. Taylor inquired whether Mr. Merkle's statements referred to an issue of precision instead of accuracy. Mr. Merkle recommended illustrating precision by presenting measured values.

Voting on Comments

The EEWG unanimously approved recommendations 1 and 2. Dr. Malinauskas explained that the comments would be sent to Dr. Kowetha Davidson and then to the ORRHES members. Ms. Horton noted the next ORRHES meeting would be held from 12 to 2 p.m. on May 3, 2005.

Additional Comments

Mr. Hanley expressed his appreciation to the work group members for their comments on the PHA, and noted that ATSDR would provide responses to the comments before the final PHA is released.

Dr. Malinauskas adjourned the meeting at 6:05 p.m.