Oak Ridge Reservation: Public Health Assessment Work Group
Public Health Assessment Work Group
October 21, 2002 - Meeting Minutes
ORRHES Members attending:
Kowetha Davidson (Subgroup Chair), David Johnson, James Lewis, Tony Malinauskas, LC Manley, and Charles Washington
Public Members attending:
Gordon Blaylock, Al Brooks, Timothy Joseph, and Linda Gass (phone)
ATSDR Staff attending:
Paul Charp, Burt Cooper, Jack Hanley, Sandy Isaacs, Bill Murray, and Jerry Pereira
- Minutes from September 16 and October 7, 2002, meetings - Bob Craig
- Update on the Public Health Assessment - Jack Hanley
- Update on the project plan
- ATSDR Radiation Screening Level - Paul Charp
- New business
Purpose: Kowetha Davidson called the meeting to order and explained that Bob Craig could not attend the meeting. Attendance was noted for the record.
Minutes from September 16, 2002, and October 7, 2002, Meetings
October 7, 2002 Minutes
Kowetha Davidson asked for comments. No one responded. LC Manley motioned to approve the minutes and Al Brooks seconded the motion. No discussion followed. The October 7, 2002, minutes were unanimously approved.
September 16, 2002 Minutes
Charles Washington motioned to approve the minutes and LC Manley seconded the motion. No discussion followed. The September 16, 2002, minutes were unanimously approved.
Update on the Public Health Assessment and Project Plan
Presenter: Jack Hanley
Jack Hanley explained that he was presenting a draft version of the project plan. Each chemical/topic will follow the same procedure (1) ATSDR will begin evaluating the chemical/topic and as they are doing so, will present the data being used to the PHAWG, (2) after the evaluation, ATSDR will verbally discuss preliminary results with the PHAWG, (3) the PHAWG will then have 30 days to comment on the preliminary results, (4) after ATSDR addresses the PHAWG comments, a written evaluation will be presented to the PHAWG, (5) the PHAWG will then have another 30 days to comment, (6) after ATSDR addresses the PHAWG comments, the evaluation will be presented to ORRHES, (7) ATSDR will address ORRHES comments, and (8) distribute the evaluation. He emphasized that there are multiple opportunities for comments—when ATSDR presents the data, after the verbal presentation, and after the written presentation.
As an example, Jack Hanley explained that in 2001, ATSDR verbally presented to the PHAWG and ORRHES the process of chemical screening for past exposures, including the state of Tennessee’s evaluation. In February 2002, the process was endorsed by the PHAWG and ORRHES. ATSDR will draft a written version of the chemical screening process for past exposures and will submit it to the Department of Energy (DOE) for a classification security review. After DOE’s review, ATSDR will present the written draft to the PHAWG for comments. After the PHAWG comments are addressed, the written draft will be presented to ORRHES for approval.
Jack Hanley emphasized that the purpose of his presentation is to demonstrate the overall steps of the project plan. There is flexibility within the process. For example, if there is a key issue that PHAWG would like to take to ORRHES, it can be done while ATSDR continues with the process. He said that the key to staying on schedule is for ATSDR to get the documents to PHAWG on time and for PHAWG to submit comments within the allotted time frame.
The currently identified contaminants of concern/pathways include: iodine, uranium, mercury, White Oak Creek releases in the 1950s, PCBs, fluorides, the TSCA incinerator, and groundwater. ATSDR will screen data from 1990 to the present to determine if there are additional contaminants of concern that will need to be addressed.
Jack Hanley explained that after each site-specific contaminant or site-specific topic is addressed, ATSDR will create a site-wide assessment that compiles the findings from each individual assessment into one summary document, with each of the individual documents attached as a stand-alone appendix. There will be site-wide public health implications and community concern sections along with an overall summary of all the conclusions.
Jack Hanley explained that this process was new and different from how ATSDR has approached other sites. Because there is so much interest and concern in the topics, ATSDR has developed this project plan to be able to address the community’s concerns early in the process.
James Lewis asked if the comment period allotted 30 working days or 30 calendar days (i.e., 20 working days). His concern is that the PHAWG have at least two meetings within the comment period. He also wants to make sure that comments that are generated during the two PHAWG meetings are captured. Tony Malinauskas agreed that two PHAWG meetings should be held within the comment period and recommended that the PHAWG receive the document one week prior to the first meeting, before ATSDR makes the presentation. James Lewis agreed. They explained that they do not want to receive the “document” at the first meeting and then be expected to comment on it at that meeting. They want two full meetings for comments. Al Brooks said that the document can be a working draft, that may change before it is presented. Kowetha Davidson said that the PHAWG has the option to call an additional meeting, if the group feels it is necessary.
James Lewis asked if PHAWG can expect to receive the data in advance of the presentation. Al Brooks mentioned that ATSDR’s assessments will rely on data from past ORRHES documents. He asked if ATSDR could provide the references for each contaminant of concern, so that people would have ample opportunity to review the existing data. Jack Hanley replied that those reports would be a good place to start, however, they are not the only sources that ATSDR will be using.
Jack Hanley explained the draft project plan time line in response to Al Brooks’ comment that the duration column did not coincide with the start and finish dates (i.e., about 6 months elapsed in the duration column and 11 months elapsed from the start date to the finish date). There is confusion with the current draft project plan time line because some days are calendar days and some are working days. This issue will be resolved in the final “baseline” version. Tim Joseph suggested presenting the project plan in a more visual format, perhaps using a different software. Kowetha Davidson suggested having both presentation formats available.
Jerry Pereira and Tony Malinauskas voiced concern that the project plan outlines working on more than one contaminant/topic at a time. Jack Hanley explained that the project plan outlines what topics will be discussed at which PHAWG meetings. ATSDR tried to spread out the major presentations, so that the PHAWG is not overwhelmed in any one meeting. Jack Hanley mentioned that the Chair will have to manage the tasks and will need some assistance. James Lewis agreed that the Chair needs to be deeply involved and committed to getting the tasks done.
Jack Hanley mentioned that the dates may change because ORRHES meetings are not scheduled for 2003 and 2004.
James Lewis asked if recommendations/comments from the PHAWG needed to be approved by ORRHES before ATSDR can address them. Jack Hanley replied that individual comments did not need to be approved by ORRHES, however, the PHAWG may want to send group recommendations to ORRHES. Kowetha Davidson suggested that comments generated by the PHAWG can be mailed to ORRHES members in the pre-meeting mailing, which would give them an opportunity to reverse any recommendations the PHAWG suggested.
Jerry Pereira asked when does ORRHES become involved. Jack Hanley recommended that ORRHES become involved after the written draft is presented to the PHAWG, during the task titled “ORRHES presentation” on the project plan. Jerry Pereira expressed concern that ORRHES will not be involved early enough in the process. Jack Hanley responded that updates can be made to ORRHES at any time. Al Brooks remarked that the purpose of having workgroups was to avoid having to go to ORRHES too often.
Al Brooks asked when does ORRHES make their final official recommendations to ATSDR. Kowetha Davidson responded that they are made at the time of the ORRHES presentation. Al Brooks suggested adding the words “final recommendations.” Jack Hanley suggested adding an additional step entitled “presentation of significant changes from the peer review comments/ORRHES final approval.”
James Lewis presented an overhead to the PHAWG that outlined how ORRHES can be involved: (1) ATSDR will send out the data two weeks before the presentation to the PHAWG; (2) ATSDR will present to the PHAWG; (3) two weeks later, at the next PHAWG meeting, PHAWG will discuss the data and/or present preliminary comments to ATSDR; (4) two weeks later, at the next PHAWG meeting, the PHAWG will collect comments and present them to ATSDR; and (5) if there is need for a recommendation or a significant issue is raised, he suggests presenting it to ORRHES, and then sending the recommendation to ATSDR. Jack Hanley and James Lewis agreed that ATSDR would continue with the process parallel to this activity within the PHAWG and ORRHES. Al Brooks commented that the PHAWG meetings are open to ORRHES, the meeting minutes are available, and reports are made to ORRHES, which are three mechanisms for ORRHES involvement. Kowetha Davidson suggested that the PHAWG give their comments to ATSDR and present them to the ORRHES during workgroup reports, which will give ORRHES the chance to comment. Jack Hanley recommended using this process during the written presentation, not the verbal.
Kowetha Davidson mentioned that there appears to be a step missing in the project plan—ATSDR needs to address comments on the classification review, before it is presented to the PHAWG. Jack warned that the classification review may take longer than the two weeks that is currently allotted. Burt Cooper said that it varies from DOE site to DOE site how long it takes for the classification review.
Charles Washington commented that the classification review process will probably prove the most difficult task because of the change in classification procedure. It may take longer because the process has not been refined and is not consistent through out the site.
Charles Washington was concerned that there could be a problem if the document is presented to the PHAWG prior to classification review. Jack Hanley explained that the documents will go through classification review prior to being released to the PHAWG.
External Peer Review
Jack Hanley explained that all the documents will go through an external peer review, typical of ATSDR procedure. After ATSDR addresses the peer review comments, the final document will be released. Kowetha Davidson suggested that ORRHES approve the document after the external peer review process. Al Brooks and Charles Washington agreed that ORRHES should see it after the peer review, especially if there are substantive changes. Jack Hanley suggested adding a step after the peer review to outline the substantive changes that were made based on the peer review comments.
Internal ATSDR Review
One meeting participant asked about the SHADE review. Sandy Isaacs explained that it was an ATSDR internal review process.
Changes After the Document is Final
Al Brooks commented that if something crucial is discovered after the documents are finalized (“go on the shelf”), the document should be modified. James Lewis clarified that it must be something significant and ORRHES must vote on whether a “final” document should be altered. Burt Cooper responded that if new information would have a significant effect on the public health conclusion, the document would be modified. James Lewis commented that if an individual wants to take issue with ATSDR after the document is finalized, it should not have an impact on the PHAWG, since they have already approved the document.
Follow-up Public Health Activities
Al Brooks suggested adding another step to the project plan that would involve two or three public meetings to educate the public. Jack Hanley agreed and explained that ATSDR will have public meetings after the Public Health Assessments are finished to let the public know the findings. The Public Health Assessments are not the final activity for ATSDR. Within the Public Health Action Plan (in the Public Health Assessment), ATSDR will outline follow-up public health activities, such as physician education, exposure investigations, notification, public education, and/or epidemiologic studies. Burt Cooper explained that it is part of standard procedures to have public availability sessions to present the findings of ATSDR’s documents to the community. Jack Hanley explained that the sessions offer individual attention in an informal setting (e.g., poster sessions). Al Brooks would like to see the public availability sessions scheduled on the project plan.
James Lewis said it is critical that the comments generated during the PHAWG meeting are captured either by the meeting minutes or by the Chair summarizing the issues that were discussed. At the end of a meeting, there should be a list of issues and comments and some agreement upon them, so that ATSDR can start to work on them.
Jack Hanley recommended that if someone brings an issue to the table that differs from ATSDR’s approach, the issue should be put in writing for the PHAWG to review and present to ORRHES. ORRHES can formally recommend whether ATSDR should address the issue, giving ATSDR the opportunity to formally respond. Al Brooks said that a written report by PHAWG will go to ATSDR and ORRHES, and if anyone wants to add personal comments, they can. However, he said that ATSDR should not have to respond to individual comments. If an individual makes a comment that would cause a major issue to ATSDR’s process, they should refer the comment to the PHAWG or ORRHES for endorsement.
Kowetha Davidson explained that the PHAWG can choose to endorse a comment or present it to ORRHES. She stressed that the individuals in the PHAWG should act as one unit. If the PHAWG does not endorse the comment, the individual can pursue it down a different path. Jack Hanley offered that if the PHAWG does not approve the individual’s comment, the person can present the idea to the ORRHES as new business. Regardless, he said that ATSDR will address all comments in the final document.
James Lewis said that there is a form for people to use for some of the technical issues.
Radiation Screening Level
Presenter: Paul Charp
Paul Charp presented (1) background information on the screening level, (2) ATSDR’s minimal risk level (MRL), and (3) the screening protocol and rationale that ATSDR is proposing. He began by reviewing the information that had already been presented to ORRHES in February 2002. ATSDR had proposed using 50 millisieverts (mSv), or 5,000 millirems (mrem), as the lifetime dose screening value. Based upon the recommendations from the PHAWG and ORRHES, the decision was made to calculate dose, not risk.
ATSDR’s MRL is based on the Toxicological Profile for Ionizing Radiation (ATSDR 1999). The MRL is defined as an estimate of daily human exposure to a substance that is likely to be without an appreciable risk of adverse effects (noncarcinogenic) over a specified duration of exposure. The current MRL for external, chronic exposure is 1 millisievert/year (mSv/y), also equivalent to 100 millirem/year (mrem/y). The chronic MRL is based on exposure to average US background radiation levels. The current MRL for external, acute exposure is 4 mSv/y (400 mrem/y). The acute MRL is based on IQ reduction in A-bomb survivors. In creating an MRL, ATSDR takes into account variability and uncertainty within the studies.
Paul Charp explained that background radiation needs to be accounted for. He explained the components of background radiation (e.g., soil, cosmic) and presented some typical dose levels of background radiation (e.g., inhaled is 2.0 mSv/y). He explained that terrestrial sources varied with altitude, latitude, and longitude and presented background radiation doses from some terrestrial sources. He also presented typical indoor radon levels in five counties within Tennessee.
Paul Charp explained that ATSDR’s screening value is 50 mSv (5,000 mrem) for a lifetime exposure (70 years), which is equivalent to about 0.71 mSv/y (which is about two times higher than the terrestrial background for the Southeast, 0.15 to 0.35 mSv/y). In response to a question, Paul Charp responded that medical procedures were not considered in background levels.
The International Commission on Radiological Protection (ICRP) proposed harmonization of radiation doses to levels of health concern. Paul Charp noted that when ATSDR’s screening level is compared to ICRP’s scale, it falls between the normal and raised categories. When he compared ATSDR’s screening level to typical doses from medical procedures (e.g., a CAT scan), it was fairly low on this scale as well. Al Brooks commented that the screening dose is not much different from medical diagnostic procedures.
Paul Charp presented two flow charts that had been presented at the February 2002 meeting.
Paul Charp explained that “no apparent concern” applies to sites where exposure to site-related contaminants might have occurred in the past or is still occurring, but the exposures are not at levels expected to cause adverse health effects. He noted that there is sufficient evidence (e.g., epidemiological reviews, the MRL) to support the use of 50 mSv (5,000 mrem) as the screening value (i.e., the level that will not cause an adverse health effect). He also explained that ATSDR will take into account special dose issues, such as bone-seeking radionuclides, such as strontium.
Letter Submitted by Bob Peelle
Paul Charp discussed a letter (that was handed out at the meeting) submitted by Bob Peelle. He explained that the 0.3% discussed in the letter would be from one year of exposure, however, ATSDR is using 50 mSv over 70 years. Paul Charp explained that dosimetry assumes that the committed dose is delivered in one year, however the dose is integrated over 50 years for workers and 70 years for the public.
Tony Malinauskas asked what was the effect from setting this screening level. Paul Charp responded that after dose calculations are estimated and compared to the lifetime screening level, anything below the screening value will be considered not of health concern. If it is above the lifetime dose, ATSDR will perform a more detailed evaluation to determine what, if any, health consequences may result from the dose.
Al Brooks asked if ATSDR’s screening levels are the same as EPA’s. Paul Charp said no, EPA’s MCL is entirely different from ATSDR’s MRL.
Kowetha Davidson asked why an uncertainty factor of 3 was used to calculate the MRL. Paul Charp responded that ATSDR will try to provide a copy of the MRL worksheet to help answer that question.
Al Brooks suggested comparing ATSDR’s screening value to total background levels, rather than terrestrial sources. Paul Charp said that he will adjust the comparison to be against total background.
Tim Joseph recommended that mrem units be used consistently (as opposed to sieverts), since more people have a better understanding of that unit.
Al Brooks asked if anything was known about populations who live in areas with high levels of background radiation. Paul Charp responded that in cases where people live in areas with 100 to 1,000 times US background levels, they observed an increase in the number of chromosomal aberrations, however, have never observed any associated adverse health effects. Al Brooks said that this is valuable information because it represents long-term effects over several generations. In addition, Al Brooks said that ATSDR’s screening level is about 20% of the local background level, and this level is not known to cause harmful health effects. Given this information, he concluded that ATSDR is using a large safety factor.
James Lewis remarked that we should emphasize public health concerns, not individual health concerns, for the general population. Paul Charp agreed.
Sandy Isaacs remarked that MRLs are the screening level, and at that level there is no evidence of appreciable health effects. Anything above 50 mSv does not mean a change in the category, it just implies that there is a need for further investigation. Therefore, she suggested removing “upper bound” from the conclusion category slide. Paul Charp agreed to change the sentence to read “... there is sufficient evidence to support its use of 50 mSv (5 rem) as a level of no apparent concern for whole body exposures.”
In response to a question from Tony Malinauskas, Paul Charp explained that ATSDR will develop a different screening value for the thyroid. Several members discussed the issue of biological half life, effective half life, and physical half life of iodine in the thyroid.
Kowetha Davidson asked if the bone-seeking radionuclides will be screened at the same level. Paul Charp replied that the method was not yet determined.
In response to a question about cobalt, Paul Charp replied that it is uniformly distributed. The body sees the cobalt, for example, as the energy being emitted from the radioisotope, so based on the dose, the health effects would be about the same.
Al Brooks asked Paul Charp to explain what “using appropriate public health measures” means. It means appropriate by the way of evidence.
Paul Charp said that studies in humans are limited, however, there are many good animal studies. He qualified that depending on the outcome looked for, one may or may not see effects. Gordon Blaylock remarked that effects are primarily found in the reproductive system, which seems to be the most sensitive system. However, there is a problem when looking at natural populations because it is hard to get good numbers. Kowetha Davidson asked what reproductive system effects are seen. Gordon Blaylock responded that number of offspring, abnormalities in fetuses, and chromosomal aberrations are looked at and added that there are many studies conducted on drosophila (fruit fly). Kowetha Davidson mentioned that in somatic cells the only association is cancer, while it does not matter when it comes to germ cells. Gordon Blaylock replied that Mike Bender found chromosomal breaks in somatic cells, but not in germ cells. Charles Washington mentioned that there was another study that looked at the effects of low level radiation and they found no effects. James Lewis suggested that if there are specific studies that PHAWG would like Paul Charp to look at, they should make a list. Gordon Blaylock and Paul Charp discussed some studies and agreed that Paul Charp knows of the studies mentioned.
Paul Charp presented a chart from the General Accounting Office on risk of radiation standards. He pointed out the intersection for ATSDR’s screening value after 70 years of exposure. He explained that in the higher risk model, one may not see any effects. Some people say that at lower doses there are higher risks than you would normally see closer to this intersection here (shown in meeting). Kowetha Davidson asked what mechanisms were proposed to explain that phenomenon. Paul Charp was not sure. In response to a question, Paul Charp verified that he was explaining higher risk than the linear model, not higher risk than ATSDR’s screening level. One meeting participant said that one of the implications of the higher risk model is that radiation catalyzes the repair mechanism. Al Brooks said that he is bothered by looking at higher risk models with very small risks. Kowetha Davidson remarked that determining what the risk is depends on the model and the assumptions. Several members discussed what threshold and linear models would look like.
James Lewis was concerned that the issues that are raised at the PHAWG meeting be captured, to avoid having to revisit the same issues. He also wants the public to know that certain issues have been raised by PHAWG and that there is an answer. He thinks it is important for the public to know that certain things have been challenged in advance and that there is a response. He suggested having an organized list of issues and their responses. Kowetha Davidson replied that the some of the comments, such as those that apply directly to Paul Charp’s presentation have already been addressed during the presentation and discussion that followed, and do not need to be captured. However, other general issues for ATSDR are a different matter and should be captured. Charles Washington mentioned that peer reviews will help. Jack Hanley mentioned the community concerns database.
Sandy Isaacs commented that the definition of the MRL specifically mentions noncarcinogenic adverse effects, and this is true for most substances. However, when the MRL was derived for radiation, all types of adverse health outcomes, both cancer and noncancer, were considered. Several meeting participants discussed how and whether it is possible to add cancer and noncancer health effects. Kowetha Davidson suggested not using that terminology since there is confusion with applying MRLs to radiation. Sandy Isaacs suggested clarifying the MRL definition to explain that radiation is the exception.
Kowetha Davidson suggested that after Paul Charp’s presentation to ORRHES, the issue should be remanded to the PHAWG and that the PHAWG should bring a recommendation of acceptance or non-acceptance of ATSDR’s screening to the next ORRHES meeting (December). Bill Murray commented that there are three PHAWG meetings between now and the December 3, 2002, ORRHES meeting and one meeting is devoted to the thyroid specialist (November 18, 2002). James Lewis suggested that the sooner the issues are discussed, the better. PHAWG members discussed scheduling.
Bill Murray said that he sent an e-mail to PHAWG members and the community asking for questions, issues, or concerns for the thyroid endocrinologist and he only received one response so far. He reiterated that if anyone has any questions, issues, or concerns that should be addressed by the thyroid specialist to please let Bill Murray know. James Lewis suggested summarizing the concerns that have already been raised.