The overall goal of the proposed research is to evaluate neuropsychological outcomes in adolescents exposed to polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), methyl mercury (MeHg) and other contaminants via consumption of fish from highly polluted waters in northeastern Wisconsin. This research will expand our ongoing study of neuropsychological function in Southeast Asian (Hmong) immigrants from this region to include similar evaluations in adolescents from the general population of sport anglers. In a recent survey, 60% of residents in northern Wisconsin reported they had participated in fishing during the past year. Waters in the northeastern part of the state contain unacceptably high levels of both PCBs and MeHg, and fishing advisories for both contaminants have been in effect continuously for many years. PBDE levels in fish from the region are unknown, but concentrations in fish from nearby Lake Michigan have been increasing at an exponential rate in recent years. The popularity of fishing in northern Wisconsin, together with the well documented contamination of waters in the northeastern part of the state with PCBs and MeHg, make this region an ideal location for assessing the risks to human health from contaminants in fish. Adolescence is a period of rapid brain growth and development, yet very little is known about the impact of exposure to PCBs or other chemicals during this period on cognitive functioning. Many aspects of executive function are maturing during adolescence, and research in animals suggests that executive functions are particularly vulnerable to disruption by PCBs. Several prospective studies have followed PCB-exposed children from birth through 9-11 years of age, but the primary focus of those studies has been to assess the long-term consequences of prenatal PCB exposure rather than the impact of exposure occurring during childhood/adolescence. In this study, we will recruit 14-18 year-old children of licensed anglers living in the region. Children will be assessed on a battery of neuropsychological tests that assess specific aspects of executive function including working memory, cognitive flexibility, attention, inhibitory control and planning ability and blood samples will be collected for contaminant analysis. Only one published study has assessed the relationship between current PCB body burdens and cognitive function during adolescence. Thus, this research will fill a very important gap in our knowledge about the neurological effects of PCBs. We hypothesize that exposure to PCBs and the chemically similar PBDEs?as measured by serum concentrations at the time of assessment?will be associated with poorer performance on tests of executive function. In particular, we predict that tests measuring inhibitory control, processing speed, planning and problem-solving will be particularly sensitive to PCB and PBDE exposure because these aspects of executive control are actively maturing during late adolescence. Project Narrative This research will investigate the impact of exposure to several widespread chemical contaminants including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and methyl mercury (MeHg) on neuropsychological function in 14-18 year-old children. Adolescence is a period of rapid brain growth and development, yet very little is known about the impact of exposure to chemical contaminants during this period on cognitive and behavioral function.
