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Post-Doctoral Fellowships
The Polybrominated Biphenyl (PBB) Cohort
Brominated flame retardants (BFRs) are synthetic chemicals, found in a wide variety of consumer
products including fabrics, furniture, plastics, computers and other electronics. BFRs may be
toxic and show hormonal or anti-hormonal properties in vitro and in wildlife. These chemicals
have been associated with adverse health effects in humans, including spontaneous abortions
and breast cancer. A unique opportunity to study possible effects of BFR exposure was presented
in the mid 1970s, when Michigan residents, as a result of an industrial accident, were exposed
to Polybrominated Biphenyl (PBB), a member of the BFR chemical group, through contaminated
food. Prior to the Michigan disaster, little was known about the possible human health effects of
BFRs. Early studies in exposed residents focused on acute health effects such as liver, immune,
and neurological function. Later, as concern grew about the endocrine-disrupting potential of
these chemicals, studies focused on reproductive effects. Because PBB can cross the placenta and
concentrates in breast milk, children born after the incident were exposed in utero and early
infancy, during a critical window in their development. Participants have been followed for 40
years and three generations, enabling, apart from direct exposure-outcome assessment, to study
the possible fetal origins of adult disease and multigenerational effects of exposure, including
biological mechanisms, epigenetic phenomena and gene-environment interactions. This cohort
includes over 4,000 Michigan residents.
At this stage the focus is on recruiting study participants from the original PBB cohort, in order
to engage them in ongoing studies. This involves having community meetings, working with
participants to administer informed consent, complete questionnaires, facilitate specimen collection
and anthropometric measurements. All participants are asked to provide a blood sample to measure
current PBB blood levels.
These studies are assessing several health outcomes, and include three levels of participation.
The first level involves completion of a general health questionnaire which includes questions on
thyroid dysfunction, neurodegenerative and musculoskeletal disorders and cancer. In level two,
participants in reproductive age groups are offered to participate in a reproductive health study,
which includes: anthropometric body measurements, height, weight, body fat percentage and
digits 2 and 4 ratio, and completing an in-depth questionnaire on reproductive history and gender-
specific reproductive health dysfunction, cancers and treatments. The third, more detailed level of
participation, involves collection of human specimen (semen and urine in males; three menstrual
cycles daily urine in females), which will be analyzed for hormone levels and activity, menstrual
function pattern, spermatogenesis and infertility.
Analysis of the data will clarify the possible association between level of exposure to PBB and the
risk for selected, general and reproductive adverse health outcomes.
Fellow
Tamar Wainstock
Emory University, USA
Supervisor
Michele Marcus
2013-2015