Oak Ridge Reservation: Public Health Assessment Work Group

Public Health Assessment Work Group

September 15, 2003 - Meeting Minutes

Attendance

ORRHES Members attending:
Bob Craig (Chair), LC Manley, Kowetha Davidson, James Lewis, Susan Kaplan, Pete Malmquist, George Gartseff, and David Johnson

Public Members attending:
Tim Joseph, John Merkle, Gordon Blaylock, and J.D. Hutchins

ATSDR Staff attending:
Bill Taylor, Melissa Fish, Jack Hanley-telephone, Dee Williamson-telephone, and Lorine Spencer-telephone

Purpose

There were four items on the agenda for discussion.

1. Review of PHAWG Meeting Minutes of 9/2/03
2. Discussion of Cancer Incidence Review
3. Brief presentation about Public Health Assessment conclusion categories
4. Presentation about past Mercury exposures
1. Air releases of mercury
2. Inventories not accounted for

Meeting Minutes

Pete Malmquist said that he was not at the September 2^nd PHAWG meeting. Pete asked if the overheads that Bill Taylor used in his presentation are available in the office. Without a copy of the overheads, a person coming into the office a year from now would not understand what went on and what the individual comments and concerns noted in the minutes were actually referring to. Bill Taylor told the group that a copy of the overheads and the handouts are available in the binders with the minutes.

James Lewis stated that the September 2, 2003 meeting minutes were adequate for the casual observer. James felt that Melissa Fish’s previous detailed minutes were better and that the quality and style of the previous minutes were beneficial to the work group as well as those who could not attend the meetings. James asked that the group give consideration to the meeting minutes issue and said that the meeting minutes issue may be discussed in more detail in COWG. James added that the work group minutes are the only product that the work groups’ produce and that the work group meetings deserve quality minutes.

Susan Kaplan agreed with James Lewis and added that the meeting minutes Melissa Fish previously produced were like actually attending the meeting. Susan felt that the previous minutes played a role in bringing a person up to speed on the topic if they had to miss a meeting.

Bob Craig said that he appreciated the input and that the group is trying to strike a balance with the meeting minutes’ issue. Bob added that meeting minute structure varies among different organizations.

James Lewis said that some people feel that the public issues have been lost. The “he said, she said” is beneficial to outsiders who are trying to become involved in the process. James went on to say that the group needs to consider other people who are not members of the work group or who are not able to attend every meeting. James added that flexibility is also important with this issue.

David Johnson stated that detailed minutes, like those that were originally being produced by Melissa Fish are an important part of packaging the science/facts for people off the street. The previous minutes allowed a person to understand what had transpired over the course of time.

James Lewis said that the group might not understand the value of what they were getting. James said that many times the work group has to return to the same issues over and over because the issue was not previously captured in a detailed type manner.

George Gartseff said that he disagrees with James Lewis about the meeting minutes being a product, rather George views the minutes as a record. George does agree that the work group meetings are where most of the vocal public input takes place. George suggested a possible solution being that the group have carry-over agenda items so that ongoing community input is captured and that the community is part of the process. Also, people should make sure that their quotes were captured correctly so that the other types of arguments are avoided.

Bill Taylor told the group that the decision to make the September 2nd meeting minutes different was done as somewhat of a pilot in order to get feedback from the work group and community members. There has been internal discussion about the minutes and it is important to address the issue of what purposes the minutes serve. The meeting minutes seem to have different purposes and value for different people. Bill Taylor told the group that he appreciated the discussion.

David Johnson stated that each person who reads the meeting minutes has their own agenda and personality; with that in mind, it raises the question of how much detail is enough.

Tim Joseph asked how long it had taken to create the previous detailed minutes. Melissa Fish responded that the previous detailed minutes took approximately 16 hours.

Bill Taylor said that he understands the value of the previous detailed minutes. Bill asked the group what do they lose in the abbreviated format. Bill said that Melissa is still capturing the concerns but the aspect that is missing is the “who said what.”

Bob Craig said that if a person is interested in the full detail of a meeting that the person can listen to the tape. Tim Joseph agreed with Bob Craig and said that he would listen to the tape if he were interested in additional detail beyond what the minutes supplied. Tim added that if he were really interested in a meeting, he would likely prefer the audiotape to the meeting minutes.

Susan Kaplan responded saying that not all people are auditory learners and that some people are visual learners.

Bill Taylor told the group that any person is welcome to come to the office and speak to him if they miss a meeting. However, this option is only helpful for the duration of the field office operation.

James Lewis said that the minutes are one component of running an effective meeting and the other component of an effective meeting are the skills of the chairperson. James felt that the meeting minute issue is a dynamic issue and is not a simple issue. James added that there are things that can be done to help the person taking the meeting minutes.

The group did not vote to approve the September 2, 2003 PHAWG minutes. The vote to approve the September 2, 2003 PHAWG minutes was postponed.

The meeting minutes issue was revisited at the end of the meeting.

Discussion of Cancer Incidence Review

Dee Williamson reviewed the draft Assessment of Cancer Incidence PowerPoint presentation that she plans to present to ORRHES at the October meeting. Topics of the presentation included the purpose, geographic area, cancer incidence data, statistical methods, interpretation, examples, strengths, and weaknesses of the assessment of cancer incidence. A copy of the presentation is available in the field office.

Dee Williamson and Pete Malmquist pointed out that the 49 census tracts surrounding Oak Ridge will be looked at as one large group rather than individual census tracts.

Bob Craig’s questions helped to clarify that the geographic area of interest is based on the areas that ORRHES defined earlier in the process.

Because it was noted that thyroid cancer as well as “sarcoma” was missing from the list of cancers to be examined, Dee Williamson said that she would check with Toni Bounds to make sure that she (Dee) has included all of the cancer types that the state has complete data for (1990-1996).

Pete Malmquist pointed out that gender was not in the list of demographic and medical data available on each individual cancer patient. Dee Williamson said that the list of limited data available should include: name, address at time of diagnosis, census tract code, primary cancer site, histology type, age at diagnosis, race, and gender.

Susan Kaplan pointed out that many people go to Vanderbilt and other outside areas for treatment: Where would those people be listed? Dee Williamson responded that the cancer incidence is reported for the area that you are living in at the time of diagnosis and not the area where treatment or diagnosis occurs.

Dee Williamson pointed out that she would take into account age and race for different cancers. Dee also explained that the data for each different cancer type and for each gender would be reported individually per county/area of interest. Dee added that she will be providing a descriptive analysis and that the analysis will not establish a cause and effect. Data is not available concerning risk factors or the length of time people have resided in particular counties. Dee Williamson also explained that a small number of cases often create unstable results.

In addition, Dee Williamson noted that the Tennessee Cancer Registry has its own set of limitations. She added that the group will be looking at descriptive information about the population level and not the individual level, and Dee reiterated that this type of analysis would not be able to establish a cause and effect.

After noting that lung cancer was listed as a cancer type to be examined, Gordon Blaylock asked if smokers versus non-smokers would be included in the lung cancer category. Dee Williamson said that the Cancer Registry does not have information regarding smoking status, which is one of its limitations.

There was some confusion expressed regarding the dotted lines on the ORRHES Geographic Areas of Interest map. It was decided that ATSDR would clarify the purpose and/or meaning of the dotted lines or get rid of the dotted lines as appropriate.

Pete Malmquist requested input from the group regarding the types of responses that should be given when a particular type of cancer is elevated in a certain geographical area. Pete feels that with 26 different cancers, most likely there will be some elevated cancer levels.

James Lewis asked about situations like example three. When it appears that there are an elevated number of cases but there is very little information, how will these types of issues be addressed? James feels that many questions or challenges could result from situations like example three.

Kowetha Davidson said that Dee Williamson would need to incorporate her explanation for each result.

Tim Joseph said that it is difficult to explain the term confidence interval to the public. It is extremely important to clearly explain the confidence interval to the public in language that the general public can understand. If not, the public would look at the numbers and be unnecessarily alarmed.

Jack Hanley suggested that one way Dee Williamson could effectively communicate with the lay public is to provide an example such as changing the cancer number by one or two cancers so that the public can see what happens.

Dee Williamson is concerned about what type of information will go to the media. Dee asked the group what they are comfortable with going to the media. Dee also asked how the group should address the cancers that are found to be a true elevation. Because there will most likely be elevated cancer findings, Dee would like the groups involved (Tennessee Cancer Registry, ORRHES, and ATSDR) to develop a plan as to how to communicate elevated cancer findings.

Bob Craig said that the group should look at the data prior to establishing a plan. Bob feels that it is not a good use of time to work on developing responses before the group sees the data.

Jack Hanley pointed out that the National Cancer Institute has a website with fact sheets for almost all cancers. Thus, if there is an elevated cancer the NCI fact sheet could be used to inform the public about what is known about the cancer. After some discussion, the group decided that fact sheets for all 26 cancers should be included regardless of whether or not the cancer is elevated.

Kowetha Davidson said that it is important to clearly establish up front that any elevations in cancer incidence cannot be linked to exposure.

Susan Kaplan said that it is known that some cancers are caused by certain contaminants of concern. Susan felt that all of the information that is known about cancer and contaminants should also be presented. Dee Williamson pointed out that most cancers have various risk factors. Jack Hanley replied that the NCI fact sheets are clearly written and describe what is known about all risk factors, including environmental risk factors.

Dee Williamson pointed out that Susan Kaplan’s comment about doctors not being able to say what caused a particular cancer is true.

James Lewis pointed out that the Tennessee Cancer Registry data should be put into perspective regarding the standard that it meets. For example, there is a platinum standard and gold standard. If Tennessee does not meet the highest standards then that needs to be clearly explained.

Jack Hanley felt that there are two issues that must be clearly explained in Dee Williamson’s efforts. One issue needing to be explained is that Cancer Incidence Data is really high quality data that has been validated through quality assurance and quality control checks. Jack added that ATSDR is very comfortable with the data for the years of 1990-1996. The second issue needing to be explained is that there is a national process to evaluate registries and that the State of Tennessee is trying to improve its score/national ranking.

Bob Craig asked Dee Williamson about the timetable concerning the document. Dee Williamson said that she hopes to have the document with the actual data available by the beginning of December.

Public Health Assessment Conclusion Categories

James Lewis presented a table with the conclusion categories from the Public Health Assessment Guidance Manual. Jack Hanley explained that these are from the latest edition of the manual. Although the manual is still in “draft” status, the categories are the ones that ATSDR is currently using when writing Public Health Assessment documents.

James Lewis explained that the conclusion categories have types of actions associated with each of them. James feels that it is imperative that ORRHES members understand the logic and process that ATSDR uses when writing the public health assessment documents. James would like ATSDR to give a presentation explaining their logic and explaining the recent updates regarding the conclusion category chapter of the Public Health Assessment Guidance Manual.

Bob Craig thanked James Lewis for his presentation.

Mercury Presentation

As a follow-on to James Lewis’s presentation, Bill Taylor explained that when he is closer to completing this series of mercury discussions, he would be ready to discuss his overall thinking regarding past mercury exposures. Bill added that the conclusion categories serve as a pivotal point in the PHA document. The categories serve as a place to consider follow-up actions.

Bill Taylor read aloud two technical reviewers’ comments that he would be addressing in his presentation.

• Some reviewers thought it was inappropriate to consider the transport of uranium particulate matter as a model for mercury vapor.
  
• Some reviewers were concerned about the large amount of mercury unaccounted for.

Overhead One

Bill Taylor explained that the problem regarding mercury releases to air is that the earliest off-site ambient air mercury concentrations were measured in 1986, but the highest Y-12 mercury releases to air were during the period of 1953 to 1962. As a result, the Task 2 team estimated air mercury concentrations from Y-12 to Wolfe Valley and the Scarboro Community. Also, Task 2 estimated air concentrations of mercury from water emissions from East Fork Poplar Creek in the areas of Scarboro, Robertsville School, an EFPC Farm Family, and two Oak Ridge community locations.

Overhead Two

Bill Taylor explained that for Wolf Valley, Task 2 modeled air concentrations of mercury for 1950-1963 using the EPA ISCST3 (Industrial Source Complex Short Term) Version 96113 (1995) which was appropriate for relatively flat areas.

Bill Taylor explained that the EPA model included 114 point source terms including 9 buildings, 62 stacks, 43 fans, and 9 vents. Bill provided a picture from the Task 2 Report depicting the 114 point source terms. Bill Taylor said that the EPA model predicts mercury concentrations at Wolf Valley from each source term and that the total annual average mercury air concentrations are equal to the sum of contributions from each point source.

LC Manley said that one technical review said that the EPA model was not appropriate because of the terrain. LC said that the model is correct for flat terrain but asked about other areas like Pine Ridge. LC said that a model for flat terrain should not be applied to the entire area. Bill Taylor responded that the model was not applied to the surrounding areas.

LC Manley said he feels that the EPA model is valid for Wolf Valley but not for the surrounding areas.

Bob Craig agreed with LC and said that the EPA model is appropriate for Wolf Valley but not other areas.

John Merkle suggested that to understand the issue better it might be helpful to draw contours of concentrations depending on the distance from the source to see how the shape of the contours compare with the topography.

Overhead Three

Bill Taylor said that the Task 2 team recognized that the EPA model was not appropriate for Scarboro and used a different method for estimating air mercury concentrations in Scarboro. The model used for estimating air concentrations in Scarboro is based on uranium.

Bill Taylor explained that the mathematical quantity (“empirical chi over Q”, or χ/Q) is based on two physical quantities. Greek letter chi (χ) is the estimated uranium concentration in Scarboro and Q is measured air releases of uranium from Y-12. The Task 2 team used the uranium quantities along with the average annual release rate of mercury from Y-12 to estimate the concentration of mercury in the Scarboro area.

LC Manley pointed out that uranium is particulate matter and mercury is a gas or a mist that would go further and higher than uranium. Bill Taylor agreed with LC Manley’s concern and went on to explain that Task 2 might be overestimating the mercury concentration in the Scarboro area by using uranium as a model.

Bill Taylor explained that the differences between uranium and mercury were that the uranium stacks were generally higher than the release points for mercury. A higher release point from Y-12 would suggest that more of the uranium got over the Pine Ridge than would have otherwise crossed over if the release points from the stacks and from the buildings would have been closer to the ground. So, the higher release point would increase the amount of uranium in Scarboro, which would increase the empirical quantity in the calculation and overestimate the amount of mercury for the Scarboro area.

Bill Taylor explained that as LC Manley mentioned, uranium is particulate matter and mercury is a vapor, gas, or mist and it is generally expected that as a gas, mercury would travel further and higher than uranium. So, by using the model of uranium, the model actually is increasing the quantity that would arrive in Scarboro because the uranium would settle out quicker than mercury. So once again, using uranium as a model may overestimate the mercury concentration in the Scarboro area.

Bill Taylor pointed out that these are potential problems with using the uranium method. So, why did they use it? Bill Taylor said that the air dispersion models that were available did not model complicated terrain. Bill was told that the Task 2 team tried the data in several different models and was unsuccessful at predicting air concentrations over Pine Ridge. Thus, the Task 2 team used the uranium relationship of releases from Y-12 and concentrations in Scarboro as the best model for what the concentrations of mercury in the Scarboro region might have been.

Kowetha Davidson asked if the Task 2 provided detail as to the proportion of how much mercury was vapor and how much was mist? Bill Taylor responded that Task 2 was considering annual averages and assumed the averages were all in the elemental mercury state and were a vapor.

LC Manley said that a major problem is that there are so many assumptions rather than hard data regarding mercury. LC said that the assumptions bothered him to the point that he cannot accept the results.

Tim Joseph responded to LC Manley saying that both calculations were an overestimate of the mercury concentrations.

Bill Taylor agreed with LC that the estimated mercury concentrations were highly uncertain but stated that the calculations set an upper boundary and that it is not believed that the mercury levels were higher than what the Task 2 people estimated. Bill also acknowledged that the group would never know, but that the calculations provide a ballpark figure as to what the maximum levels might have been.

Gordon Blaylock said that modeling is used when there is no answer. Gordon told the group to not take the modeling data as the actual number, but that it is the best information that is currently available regarding past mercury concentrations in Scarboro.

Tim Joseph and Bob Craig added that Task 2 was trying to be conservative.

In response to a question regarding how comfortable he feels that the mercury concentration would fall below the numbers calculated, Gordon Blaylock said that based on all of the assumptions, this is the best information that is available right now. Gordon Blaylock reminded the group that this is modeling; this is when you do not have all of the data.

Overhead Four

Bill Taylor discussed the vapor being released from East Fork Poplar Creek. Bill Taylor said that it is known that water mercury concentrations in East Fork Poplar Creek near Y-12 are higher than those in East Fork Poplar Creek near the Poplar Creek junction. It was estimated that 60-90% of mercury “lost” in EFPC goes to sediment and air. The best Task 2 estimate is that 5% of the mercury mass in the creek volatilized.

Bill Taylor displayed Figure 7-5 from the Task 2 Report that shows that consecutive segments spanning the length of East Fork Poplar Creek provided the source terms used to calculate the air mercury concentration at the various population centers. For each segment of the creek, the mass of mercury remaining in the water at that point contributed a fraction of the mercury that evaporated from the water, which was used in the EPA dispersion model.

Bill Taylor also explained that tree rings were studied and were determined not a reliable measure of air mercury concentrations for different years because the mercury did not stay put in a tree ring.

Another area that the Task 2 Report looked at but did not spend a lot of time on was East Fork Poplar Creek soil emissions. The Task 2 team considered some studies that concluded that emissions from EFPC soils were insignificant compared with emissions from the EFPC water.

Overhead Five

Bill Taylor used overhead five in conjunction with overhead four. Overhead five is figure 7-5: Conceptual Model for Mercury Releases from EFPC Using the ISCST3 Air Dispersion Model from the Task 2 Report.

Overhead Six

(Figure 7-2: A bar graph of air concentrations of mercury at Scarboro from both Y-12 air releases and EPFC water emissions.) LC Manley asked if there is a similar graph for the area near Bruners. Bill Taylor responded that Bruners was not a location for which they estimated the air concentrations of mercury.

Kowetha Davidson asked how the concentrations on the graph would compare with the source at East Fork Poplar Creek. If a person had their nose to the water level, the concentrations would be extremely high. Bill Taylor agreed with Kowetha and said that she raised an interesting question. Bill said that one of the recipient populations is the East Fork Poplar Creek Farm Family so that was probably the best guess for air concentrations closest to the creek.

LC Manley said that the Jefferson area is basically in the flood plain as well as Kmart and Kroger. LC Manley told the group that the soil contaminated with mercury was covered with new soil, which would cut down the amount of vapors.

Bill Taylor told the group that he needs to look back and see what Oak Ridge population centers Task 2 modeled.

Overhead Seven

Bill Taylor told the group that there is a large amount of mercury that is unaccounted for. Bill explained that there are two major studies that looked at the mercury inventories. One report is dated 1977 and the other is a 1983 Mercury Task Force Report in which people were interviewed and the inventory records were studied more closely.

Bill Taylor explained that the chart makes a distinction between what is lost and what is not accounted for. Bill said that the term “lost” is used to describe quantities that are estimated to have gone into the air, soil, and water. The term “not accounted for” describes what could not be accounted for in lost quantities or what could not be identified in the inventory of products. The 1983 Mercury Task Force Report identified 1,291,855 pounds of mercury as being not accounted for. It is estimated that 5% of the mercury not accounted for could be in the buildings—in the walls, floors, and pipes. Another 45% of the “not accounted for” mercury could be due to accounting errors. Mercury came into the plant in flasks that weighed 76 pounds. However, the flasks were not accounted for by weight, they were accounted for by numbers of flasks, thus mercury coming into the plant was estimated by number of flasks times 76 pounds. People who were interviewed who worked at the plants said that sometimes the flasks would arrive at the plant and not be completely full. Thus, it is likely that the incoming amount of mercury was overestimated.

Bob Craig feels that the important number being presented is the 2,025,056 pounds of mercury that are known to be lost and not accounted for, because the 2,025,056 pounds are potential exposures.

Bill Taylor said that the other 50% of the estimated mercury that was unaccounted for was not addressed in the Task 2 report. Bill said that although there is not a lot we can do with this information, it is important to keep these uncertainties in mind.

New Business

There was some discussion about the dates of the upcoming PHAWG meetings. Jack Hanley asked the group if the next PHAWG meeting could be moved to October 13th if necessary. The group agreed that it would be OK to change the PHAWG meeting date if need be. Jack Hanley plans to discuss the Y-12 Uranium PHA comments and ATSDR’s responses with the PHAWG prior to the October 21st ORRHES meeting.

Continuation of Discussion of Meeting Minutes

David Johnson asked what we were going to do about the meeting minutes. Bob Craig said we need a little more detail than in the September 2 minutes, but we are not looking for verbatim minutes. Bill Taylor explained that there is not much “in between” when considering the time and preparation regarding the meeting minutes. There are the previous PHAWG minutes and there are the most recent PHAWG minutes. The group needs to consider the value of the longer minutes versus the value of the shorter minutes.

Tim Joseph asked how long the shorter version of the PHAWG minutes took to complete. Melissa Fish said that the last PHAWG meeting took approximately three to four hours but it was a meeting that did not have many concerns or much group discussion.

Tim Joseph also asked what is not getting done when Melissa is spending her time completing meeting minutes. Melissa Fish said that the meeting minutes take away from her time working with the community concerns database. Tim Joseph feels that it is important to consider not just the amount of time, but also the value of the projects that time is being taken from.

Susan Kaplan said that because a lot of money is being spent, the 16 hours of time is well spent documenting the meetings accurately and completely.

James Lewis said that the group should not be discussing the hours or resources because resources are another group’s issue. The group should be asking themselves what is gained or lost by having more abbreviated minutes.

Kowetha Davidson wondered if it is important to get a verbatim account of a presentation if the concerns are captured. Tim Joseph also pointed out that the concerns from the last PHAWG meeting were captured in the abbreviated meeting minutes.

Gordon Blaylock pointed out that a problem with the abbreviated minutes might arise when there are controversial issues because everyone wants to know what was said. Some members of the PHAWG stated that the person could go back to the audiotape if a controversy does come up.

Both Gordon Blaylock and Susan Kaplan pointed out that it took two years to get the tapes of an ORRHES meeting to get a situation cleared up where Owen Hoffman said one thing and the synopsis showed another. Susan Kaplan said that it is not realistic to expect someone to go back and review the tape.

There was further discussion about what is and what is not considered controversial. The group seemed to agree that a concern is a concern, regardless of whether or not the concern or issue is controversial.

Jack Hanley asked Melissa Fish if in the abbreviated form of the meeting minutes she would likely include Bill Taylor’s response to LC Manley’s questions regarding using the uranium model to estimate mercury concentrations. Jack Hanley said that Bill Taylor’s responses to LC Manley’s questions were very important and needed to be captured in the record. Is there a difference in capturing the response and clear explanation to an issue when choosing the longer minutes compared to the more abbreviated minutes? Melissa Fish responded that she thought that there would be a difference.

Jack Hanley said he thought that issues that arise and have been responded to should be clearly and completely documented so that years from now people will be able to see that the issue was considered and addressed. Melissa Fish agreed with Jack Hanley and Melissa said she did not think that the shorter minutes will accurately portray the entire response to an issue.

Susan Kaplan said that the more abbreviated minutes involve more judgment than the longer, more detailed minutes. Susan reminded the group that when Melissa leaves, they would need to bring in another person to train and teach judgment. Melissa Fish agreed with Susan Kaplan’s concern. The abbreviated minutes call into question what responses are worthy of being captured and which are not.

James Lewis stated that the more complete minutes have clear advantages that need to be considered.

Kowetha Davidson told the group that the PHAWG is getting into a situation where the PHAWG minutes are more detailed than ORRHES meeting minutes. It is important to determine the benefits and costs regarding the meeting minutes detail because there are finite people and finite resources. James Lewis disagreed with Kowetha and said that resources are a management issue. Kowetha Davidson disagreed with James Lewis and said that the issue of finite people, time, and resources is a reality.

Bill Taylor told the group that he feels that this discussion needs to be decided by ORRHES if ORRHES chooses to do so. If not, the decision will be made by ATSDR.

Susan Kaplan made a motion for the work group to use the more complete meeting minutes. The motion was seconded. The group voted 5 to 5 with Kowetha Davidson breaking the tie by voting against the more complete minutes. The motion failed.

Action Items

• Cancer Incidence Review
  Dee Williamson will check with Toni Bounds to make sure that the list of cancer types is complete.
  
• ATSDR will clarify/explain the purpose of the dotted lines on the ORRHES Geographic Areas of Interest or get rid of the lines, as appropriate.
  
• Dee Williamson’s efforts need to include explaining that Cancer Incidence Data is high quality, how does the quality of the State of Tennessee Registry compare with other states, and that the State of Tennessee is actively trying to improve its national registry ranking.
  
• Public Health Assessment Conclusion Categories
  ATSDR should consider providing a presentation that would explain the process used in deriving specific conclusion categories for the Public Health Assessment documents.
  
• Mercury
  Bill Taylor will find out what Oak Ridge population centers the Task 2 Report modeled.
  
• Uranium
  Jack Hanley will present the public comments on the Y-12 Uranium PHA and ATSDR’s responses to them to the PHAWG prior to the October ORRHES meeting.

The meeting was adjourned at 7:45 PM.