| Polychlorinated biphenyls (PCBs) are a group of lipophilic compounds that are ubiquitous in the environment. Although banned from production in the United States in 1977, their persistent nature has resulted in bioaccumulation in the food chain. Several epidemiologic studies have investigated potential predictors of PCB concentrations or examined adverse health effects associated with PCB exposure. However, there have been few population-based studies of older adults.; Using data from a longitudinal study, this cross-sectional analysis examined: (1) the predictors of polychlorinated biphenyls in a sample from the Baltimore Memory Study population; and (2) the relationship between PCB levels and neurobehavioral function. An additional objective was to determine whether an endothelial nitric oxide synthase (eNOS) polymorphism modified the relationship between PCB exposure and outcome. Our sample, drawn from a population-based longitudinal study, consisted of 198 individuals between age 50 and 70 years who were racially diverse and living in an urban setting.; Lipid-adjusted serum PCB concentrations ranged from 0.04 to 1.57 mug/g lipid with a mean value of 0.30 mug/g lipid. Demographic factors, health history, medication use and dietary information were evaluated as potential predictors of serum PCB concentrations. Nonwhite, older age and seafood consumption were positively associated with lipid-adjusted serum PCB concentrations. More specifically, within the seafood categories, measures for total seafood as well as shellfish consumption were strongly associated with serum PCB concentrations.; The relationship between serum PCB concentrations and neurobehavioral test scores was evaluated while controlling for several covariates. All models demonstrated trends of lower neurobehavioral test scores with increasing lipid-adjusted PCB concentrations. Race/ethnicity, a complex variable, was strongly associated with serum lipid-adjusted PCB levels and neurobehavioral test scores, thus raising concern regarding the inclusion of race/ethnicity in the models. Exclusion of race/ethnicity revealed stronger associations between PCB concentrations and neurobehavioral test scores, suggesting that serum PCB concentrations may impair language, verbal memory and complex motor function domains. No evidence was found for an interaction effect between the eNOS polymorphism and PCB exposure on neurobehavioral outcomes.; The degree to which serum PCB concentrations represent total body burden is not well understood, although these results suggest a link between PCB exposure and neurobehavioral function. |
