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Summary of the Minnesota Department of Health (MDH)
Environmental Health Tracking & Biomonitoring
Advisory Panel Meeting
December 8, 2009, 1-4 p.m.
Advisory panel members – Present:
Beth Baker (chair), Alan Bender, Cathi Lyman-Onkka, Deb McGovern, Geary Olsen, Greg Pratt,
Dan Stoddard, Lisa Yost
Advisory panel members – Regrets:
Bruce Alexander, Jill Heins Nesvold, Samuel Yamin
Welcome and introductions
Beth Baker, chair, welcomed Cathi Lyman-Onkka to the EHTB advisory panel. Cathi fills the
nongovernmental organization representative vacancy left by Cecilia Martinez. Cathi serves on
the board of directors for Preventing Harm Minnesota and worked for 34 years at St. PaulRamsey County Public Health. Her areas of expertise include community involvement and
health education.
Deb McGovern announced that she is no longer employed with Essar Steel.
East Metro PFC Biomonitoring Study Water-Blood Analysis
Adrienne Kari, biomonitoring coordinator, presented preliminary results of an analysis of the
relationship between PFC levels in water and PFC levels in serum. This analysis was conducted
to determine the percent of variability in serum PFC levels that is accounted for by the PFC
levels in the water. The results of the analysis are included in the meeting packet on pages 3-10
The follow-up analysis included 98 participants from 77 households.
For the analysis, the PFC water levels were estimated based on well sampling data collected by
the Minnesota Department of Health between 2005 and 2008. The analysis was restricted to
PFOA and PFOS only. Because some wells had more test points than others, both the highest
PFC level recorded and the average level were used in the analysis. The average PFC level
measured in the water was more predictive of blood PFC levels than the highest level of PFCs
measured in the water.
Other variables that were part of the analysis include the following:
 Age: The average age of participants was 54, with a range of 20 to 86 years.

Gender: There were 44 males and 54 females included in the analysis.
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
History of 3M employment: Ten participants indicated that they had worked for 3M.

Length of residence: The average length of residence was 20 years, with a range of 4 to
60 years.

“Cessation time” (which was a proxy for estimating the amount of time since the
participants stopped drinking the contaminated water): The average cessation time was
27 months, with a range of 0 to 45 months.
The initial regression analysis found that levels of PFCs in the drinking water alone accounted
for 30% of the variability seen in people’s blood PFC levels. Additional variables were then
examined and assessed for significance.
The final PFOA model included age as a variable. Levels of PFOA in the drinking water
combined with age accounted for 42% of the variability in people’s blood PFOA levels. The
final PFOS model included age and gender. Levels of PFOS in the drinking water combined with
age and gender accounted for 40% of the variability in people’s blood PFOS+ levels.
Adrienne stated that, based on this analysis, we can predict that the steps taken to provide
alternate water sources are likely to lead to decreases in PFC blood levels.
Advisory panel members had several questions about the variables included in the model. Beth
Baker asked whether the question about 3M employment included information on length of
employment. Adrienne stated that there was a yes/no question about ever having worked at 3M
which was followed up with a question about specific jobs that may have resulted in PFC
exposure.
There was considerable discussion about the variables of age and length of residence. Alan
Bender asked whether the analysis checked for the covariance of age and residence, since those
two variables are likely related. Adrienne responded that that analysis had indeed been done and
that age was a better predictor of PFC levels than length of residence. Greg Pratt asked whether
length of residence was tested without age. Adrienne replied that this was done and clarified that
length of residence is predictive of PFC levels, but only when age is not included in the model as
well. Greg suggested that it is not accurate to say that length of residence is not predictive. Lisa
Yost suggested that age might be a better predictor because it accounts for exposure to PFCs
through all sources, not just the water. Geary Olsen wondered whether age at time of first
residence could be used to separate the age and residence variables in order to determine the
independent contributions of those two variables. Adrienne replied that the survey only asked for
length of residence at the current address, not any address in the study community. Geary agreed
that without that information, the additional analysis would not be worthwhile. Alan suggested
that a power analysis be conducted to test the model and determine what the model missed. The
fact that length of residence was not an independent predictor of PFC levels might be a function
of the number of participants included in the study.
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Geary Olsen asked whether Adrienne had the r-squared values for each of the variables tested.
Adrienne said she would follow up with an answer when she was back in the office.
Deb McGovern suggested that program staff focus on articulating what happens next with this
project and determining how to close the project out. Jean replied that the plan for closing the
project is to submit the results to a peer-reviewed technical publication.
Beth clarified that the cessation time variable was an estimate of the time since participants
stopped using the contaminated water and suggested that this be made more explicit when the
results are shared. Greg suggested clarifying that all of the variables are imperfect, that we are
using them to try to calculate exposure. Geary stated that the word “log” could be removed from
Figures 6 and 8 because the scales are already presented in log form. Lisa Yost suggested
including information on serum levels found in NHANES in our final report to the community;
even though this information was included in the first report, she felt it was important enough to
carry it forward into the follow-up report.
PFC follow-up study
Jean Johnson reminded the advisory panel that they had previously recommended that MDH
conduct a follow-up biomonitoring study to determine whether PFC levels were dropping in the
community. The EHTB steering committee approved program staff proceeding with planning the
follow-up, contingent on the continued availability of funding.
With the goal of collecting specimens in a year, a project team is beginning to plan the follow-up
study now and is seeking advice from the advisory panel on potential research questions. Some
of the potential questions stem from inquiries that program staff continue to receive from
community members and legislators.
Pages 17-27 of the meeting packet lay out the six potential research questions that advisory panel
members are being asked to comment on along with some background information on each
question.
Jean briefly described the six questions (below) and asked panel members to consider for each
question whether it is feasible (i.e., do the methods exist to address the question and provide a
conclusive answer); whether there is scientific value in addressing the question; and whether it is
responsive to community needs.
1. What are current (2010) levels of PFOA, PFOS, and PFHxS in the study population and how
do they compare to levels that were measured in 2008? (Note: PFOA, PFOS, and PFHxS
are the only PFCs that were detected in all study participants.)
2. What is the rate of decline for PFOA, PFOS, and PFHxS blood levels in the study
population? What is the half life of PFOA, PFOS, and PFHxS in this population?
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3. In addition to the drinking water, what other sources of exposure help to explain the
variability in the blood levels of PFOA, PFOS, and PFHxS?
4. What are the levels of other PFCs in the community, including those that have not been
detected in the water? [Note: The MDH laboratory can measure approximately 16 PFCs
using methods comparable to NHANES.]
5. Is there a relationship between blood cholesterol and PFC levels in this study group?
Is the rate of decline for PFCs different for people with high vs. low blood cholesterol levels?
6. Are there long-term health effects (cardiovascular, cancer, reproductive, etc.) associated with
PFC exposures:
a. In this community?
b. In the state?
Jean stated that 185 of the original 196 study participants agreed to be contacted again for future
studies. It is expected that some of these will have moved away or will decline to participate.
Conducting a limited follow-up study (e.g., measuring the current levels of PFCs in the blood,
calculating the rate of decline) with this group of participants would be feasible within the
existing budget, as long as the existing funds remain available. Expanding the study’s scope to
include additional research questions and/or other participants will require additional funding to
be secured.
Advisory panel members had a wide-ranging discussion about the potential research questions.
Their comments are summarized according to each question.
Question 1: What are current (2010) levels of PFOA, PFOS, and PFHxS in the study population
and how do they compare to levels that were measured in 2008? (Note: PFOA, PFOS, and
PFHxS are the only PFCs that were detected in all study participants.)
Jean stated that the follow-up study would be designed to address this question; it is technically
feasible, contributes to the scientific literature and responds to community concern.
Question 2: What is the rate of decline for PFOA, PFOS, and PFHxS blood levels in the study
population? What is the half life of PFOA, PFOS, and PFHxS in this population?
Beth Baker inquired whether it was preferable to have more than two data points in order to
calculate a half-life. Geary Olsen replied that because PFCs follow a first-order pharmaceutical
curve at low levels (even though they technically follow a linear curve), having just two data
points will be enough to provide assurance that there has been a decline.
Alan Bender asked what program staff saw as the value in calculating a half-life. Jean replied
that making this calculation would contribute to the scientific literature because there have been
relatively few such calculations made; she speculated that community members might be less
interested in this research question. Geary suggested that the community may in fact be
interested in seeing if the half-life is quicker than it is for 3M workers with occupational
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exposure; the C8 study of community members in West Virginia/Ohio saw a quicker half-life
than for 3M workers.
Question 3: In addition to the drinking water, what other sources of exposure help to explain the
variability in the blood levels of PFOA, PFOS, and PFHxS?
Jean explained that this question could be addressed through an expanded questionnaire or
potentially through sampling (e.g., dust samples) in homes.
Lisa Yost asked whether there would be any interview aspect in the follow-up study to determine
possible sources of exposure. Jean replied that the scope of a questionnaire (e.g., the level of
detail included) would need to be determined; consideration would be needed in terms of the
amount of value that would be added. Greg Pratt suggested that if a decision is made to go back
to participants with a questionnaire, attempts should be made to pin down as much as possible
about exposures. Lisa added that the biggest cost in the study would be to find each person and
that adding a questionnaire would constitute less of an additional cost. Jean stated that costs
would depend in part on the length of the survey and whether the survey contained validated
questions; it could take considerable time to develop.
Geary Olsen stated that it would be unlikely for MDH to identify sources of exposure. This is a
big area of investigation in the literature; if the exposures could be easily quantified this question
would have already been answered by others. Instead, the study should focus on obtaining a
better estimate of the role of the water in PFC levels; the questionnaire should be focused on
local issues. Lisa suggested that the study could attempt to get better information on the cessation
time variable discussed in the previous presentation.
Question 4: What are the levels of other PFCs in the community, including those that have not
been detected in the water? [Note: The MDH laboratory can measure approximately 16 PFCs
using methods comparable to NHANES.]
Beth Baker asked whether adding other PFCs could provide an indication of exposure to other
products. Geary Olsen stated that none of the PFCs are exposure-specific compounds and that
the shorter chain PFCs can actually be metabolites of other PFCs.
Geary stated that, in his view, the unique question that we should focus on is what is the
contribution of the water to the PFC blood levels. He suggested included PFBA in the list of
analytes (in addition to PFOA, PFOS and PFHxS) even though it was found in a smaller number
of participants. This would help confirm that the levels are no different than before and PFBA is
of particular interest in Minnesota because of the exposure in the water. Louise Liao and Carin
Huset from the MDH lab stated that adding PFBA would add minimally to the burden of the lab.
Jim Kelly from the MDH environmental health division added that PFBA is still in the water in
Oakdale at low levels, so some participants are still being exposed.
Deb McGovern stated that she supported the idea of measuring PFBA, but questioned the
purpose of including other PFCs that were not found in the water, particularly because the
messaging around those exposures would be more difficult. Lisa Yost, Beth Baker and Cathi
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Lyman-Onkka agreed that if a PFC is not related to the drinking water it should not be measured.
In addition, Lisa stated that PFCs should only be measured if there are NHANES data available
for comparison.
Greg Pratt disagreed, saying that if the additional cost to measure other PFCs is minimal, more
PFCs should be included in the follow-up analysis, even if the data are hard to interpret; such
information could be useful in the future. Geary stated that for PFCs not found in the water, the
study population would likely look like the general population. He stated that he was not
opposed to including other chemicals, but that MDH should expect levels to be at background
levels. He added that the biggest question in the study population is PFHxS levels, which are
higher than levels found in other communities thought PFHxS was generally not detectable in the
well water. He suggested that MDH could try to explore the relationship between the water
levels and blood levels for PFHxS using the data on the Oakdale municipal water.
Lisa stated that even if adding chemicals to the analysis introduces little cost, the downside of
collecting information that can’t be interpreted is that it can become more expensive later in
terms of addressing community concerns. Alan Bender stated that even if there were no
additional cost created, the MDH study should not gather information that can’t be interpreted.
His view is that MDH should be viewed as public health clinicians not public health
academicians. While gathering information that can’t be interpreted may be appropriate for an
academic setting, it’s not appropriate for MDH.
Question 5: Is there a relationship between blood cholesterol and PFC levels in this study
group? Is the rate of decline for PFCs different for people with high vs. low blood cholesterol
levels?
Question 6: Are there long-term health effects (cardiovascular, cancer, reproductive, etc.)
associated with PFC exposures in this community or in the state?
Jean stated that the studies looking at the relationship between blood cholesterol and PFC levels
have been cross-sectional. An MDH study could be designed to explore whether the difference in
PFC levels is associated with a difference in PFC rates of decline. Jean also stated that
community members frequently request for MDH to conduct a health study, such as cancer,
reproductive outcomes and thyroid.
Greg Pratt suggested that, given that we know what the distribution of cholesterol levels are in
the population and we know the rate of decline of PFCs, staff could conduct a power calculation
to determine whether it would even be feasible to measure a cholesterol association. A similar
calculation could be done for various health effects.
Geary Olsen stated that new research on health effects and PFCs is coming out every day and
that the expertise to advise such a study is not present on the current EHTB advisory panel.
Geary, in response to a question from Deb McGovern, then described the current research on
PFCs and cholesterol levels. The response is different at community exposure levels from the
response at occupational exposure levels. The increase in cholesterol at lower levels of exposure
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may be due to binding issues (e.g., PFCs binding to beta lipo-proteins and albumin) rather than
to a causal relationship between PFCs and cholesterol. He stated that other researchers are
looking at this issue and he is not sure that such a study at MDH could be adequately carried out
within the constraints of the EHTB program. Deb McGovern stated that, based on Geary’s
description, she did not support the MDH study addressing the questions of cholesterol levels
and health effects.
Beth Baker stated that, because community members are interested in information on health
effects, MDH could consider looking at the cholesterol issue if the sample size is adequate. As
long as blood is being drawn for the PFC levels, running a cholesterol test is inexpensive. Cathi
Lyman-Onkka agreed, stating that the program needs to balance research with community
expectations. Adding the cholesterol question to the project could help build credibility with the
community by responding to their concerns.
Lisa Yost stated that she would be reluctant to include a health endpoint in the study unless it can
be done with an appropriate level of rigor. Additionally, she questioned whether exposures were
high enough in this population to warrant looking at health effects. Geary stated that the current
sample size is adequate for measuring PFC levels but not sufficient for looking at health effects
(which would have required a different study design), and that MDH may not be able to add to
what is already being learned elsewhere.
Greg stated his opinion that the study should build in as much as is cost-effective and that the
first four research questions seem more feasible in this regard.
Alan Bender stated that there might be other tools available to answer the health-related research
questions, such as using Minnesota Cancer Surveillance System data.
On a more general level, Alan Bender suggested that in considering any new biomonitoring
study there should be a discussion of the philosophical framework guiding the work. If money is
spent on biomonitoring, it will mean that resources will not be available to do other work. A
question for consideration is whether the priority should be to spend money on programs where
there is a defined public health impact or on things like measuring PFCs, whose impact on health
is unknown. His view is that the health department should focus on work with known health
impacts and look to academic institutions and other researchers for guidance on PFCs as more
research is carried out.
Biomonitoring Updates
Mercury
Pat McCann, the principal investigator for the Lake Superior Mercury Biomonitoring Study,
provided an update on that project. An automated punch is now being used on the blood spots
instead of a hand punch. The number of punches needed to run the analysis has been reduced
which has resulted in an increase in the inclusion rate. Lab analysis is expected to begin in
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December. In terms of enrollment, Wisconsin has completed sample collection with 140
samples; Michigan’s participation is still on hold; and Minnesota, where informed consent is
required for participation, has received 810 consents (out of the target of 1,160). Approximately
10% of the consents received to date have been obtained with the assistance of local public
health agency staff. The participation rate in Minnesota is estimated to be about 48%. Enrollment
in Minnesota is expected to be completed by February 2010. At an earlier advisory panel
meeting, a recommendation was made to collect data in the other participating states to
determine how Minnesota’s exclusion criteria might affect participation. This information is
being collected.
Pesticide indicator
Joe Zachmann from the Minnesota Department of Agriculture, Deanna Scher from the
environmental health division at the Minnesota Department of Health, and Naomi Shinoda from
the health promotion and chronic disease division at the Minnesota Department of Health made a
presentation on the progress made in developing nationally consistent data and measures related
to pesticides. Joe reported that progress has been slow and that there is a lack of understanding
among group members of the issues and terminology. Participating states are compiling potential
data sources, which will be pooled and examined for commonalities across states. Five areas
have been identified for possible indicator development:
 Product sales and use
 Needs for pesticides (e.g., pest trends)
 Exposures
 Health outcomes (acute and chronic)
 Interventions (e.g., regulatory actions)
Deanna described national data sources being considered for inclusion. Joe described some of the
Minnesota-specific data sources related to hazards. Naomi described Minnesota-specific data
sources related to health outcomes. Further information about these data sources can be found in
the meeting materials on pages 41-86 and in the attached Power Point handout.
Panel members were invited to provide feedback in terms of establishing Minnesota-specific
priorities and identifying data gaps.
Geary Olsen asked about which health conditions are likely to be included under the category
“suspected chronic” health conditions related to pesticide exposure. Naomi responded that she
was not sure where the national program was heading but that she would urge caution within
Minnesota in terms of incorporating this into the tracking program.
Alan Bender stated that the panel could provide recommendations about where Minnesota should
diverge from the national program and could give advice to help form national priorities.
Beth Baker commented that there are data gaps in terms of health outcomes. There is no
information on occupational exposures and no information about chronic conditions.
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Tracking updates
IBIS (portal development)
Chuck Stroebel, EPHT program manager, described progress made in developing a web-based
queriable information system for the tracking program. The target date for having the system up
is September 2010. It is likely that the initial content will be somewhat limited, but that
additional content and functionality will be added over time.
Beth Baker adjourned the meeting.
Drafted 12/30/09; finalized 1/21/10
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