| Impairments of Memory and Learning in Older Adults Exposed to Polychlorinated Biphenyls Via Consumption of Great Lakes Fish Susan L. Schantz,1 Donna M. Gasior,2 Elena Polverejan,2 Robert J. McCaffrey,3 Anne M. Sweeney,4 Harold E.B. Humphrey,5 and Joseph C. Gardiner2 1Department of Veterinary Biosciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA; 2Department of Epidemiology, College of Human Medicine, Michigan State University, East Lansing, Michigan, USA; 3Department of Psychology, University at Albany, State University of New York, Albany, New York, USA; 4School of Public Health, University of Texas Health Science Center at Houston, Houston, Texas, USA; 5Institute of Environmental Toxicology, Michigan State University, East Lansing, Michigan, USA Abstract
An association between in utero polychlorinated biphenyl (PCB) exposure and impaired childhood intellectual functioning has been reported, but the potential impact of PCB exposure during adulthood on intellectual functioning has received little attention. We assessed the impact of PCBs and other fish-borne contaminants on intellectual functioning in older adults. The subjects were 49- to 86-year-old Michigan residents recruited from an existing cohort. Fish eaters ate > 24 lb of sport-caught Lake Michigan fish per year and non-fish eaters ate < 6 lb of Lake Michigan fish per year. A battery of cognitive tests including tests of memory and learning, executive function, and visual-spatial function was administered to 180 subjects (101 fish eaters and 79 non-fish eaters) . Blood samples were analyzed for PCBs and 10 other contaminants. We evaluated cognitive outcomes using multiple regression. PCBs and dichlorodiphenyl dichloroethene (DDE) were markedly elevated in fish eaters. After controlling for potential confounders PCB, but not DDE, exposure was associated with lower scores on several measures of memory and learning. These included the Weschler Memory Scale verbal delayed recall (p = 0.001) , the semantic cluster ratio (p = 0.006) , and list A, trial 1 (p = 0.037) , from the California Verbal Learning Test. In contrast, executive and visual-spatial function were not impaired by exposure to either PCBs or DDE. In conclusion, PCB exposure during adulthood was associated with impairments in memory and learning, whereas executive and visual-spatial function were unaffected. These results are consistent with previous research showing an association between in utero PCB exposure and impairments of memory during infancy and childhood. Key words: DDE, dichlorodiphenyl dichloroethene, executive function, Great Lakes fish, learning, memory, older adults, polychlorinated biphenyls, PCBs, visual-spatial function. Environ Health Perspect 109:605-611 (2001) . [Online 5 June 2001] http://ehpnet1.niehs.nih.gov/docs/2001/109p605-611schantz/ abstract.html Address correspondence to S.L. Schantz, Department of Veterinary Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, 2001 S. Lincoln Avenue, Urbana, IL 61802 USA. Telephone: (217) 333-6230. Fax: (217) 244-1652. E-mail: schantz@uiuc.edu This research was supported by grant 598339 from the Agency for Toxic Substances and Disease Registry (ATSDR) . Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the ATSDR. Received 15 November 2000 ; accepted 18 December 2000.
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