Date of Award




Document Type


Degree Name

Doctor of Philosophy (PhD)


Department of Environmental Health Sciences

Content Description

1 online resource (ii, xiii, 148 pages) : illustrations (some color)

Dissertation/Thesis Chair

Edward F Fitzgerald

Committee Members

Michael S Bloom, Kurunthachalam Kannan, Julie K Lynch, Recai M Yucel


Polychlorinated biphenyls, Older people, Behavioral toxicology, Neuropsychological tests, Thyroid hormones, Thyroid gland, Neuropsychology

Subject Categories

Environmental Health


Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants linked to changes in cognitive function and thyroid hormone (TH) levels. However, most studies of PCBs and cognitive function were conducted among children. No studies among older adults have prospectively collected PCB and cognitive performance measurements to evaluate the association over time, and no longitudinal studies have evaluated the association between PCBs and THs over time among a non-occupationally exposed population. Further, the biological mechanism by which PCBs impact cognitive function is unknown, but may be mediated by THs. In addition, reliable self-reported survey data is necessary to obtain precise disease association estimates in epidemiologic research. However, self-reported information may be less consistent in studies of older adults due to increased disease burden and decreased cognitive functioning.