Neurocognitive changes among elderly exposed to PCBs/PCDFs in Taiwan.
BACKGROUND
In 1979 approximately 2,000 people were exposed to polychlorinated biphenyls (PCBs) and polychlorinated dibenzofurans (PCDFs) due to ingestion of contaminated cooking oil in Taiwan. Although a previous study has shown delayed developmental milestones and poorer neurocognitive functioning in children born to exposed mothers, it is unclear whether neurocognitive functioning was impaired in people who were directly exposed to the PCBs and PDCFs.


OBJECTIVE
The objective of this study was to compare neurocognitive functioning in people exposed to PCBs and PCDFs with that of unexposed sex- and age-matched neighbors.


METHODS
We conducted a retrospective cohort study among exposed and unexposed subjects > or =60 years of age using prospective outcome measurements. We evaluated neurocognitive tests including cognition, memory modalities, learning, motor and sensory function, mood, and daily activity.


RESULTS
In total, 162 (59%) exposed and 151 (55%) reference subjects completed this study. In exposed men, all test results were similar to the reference group; however, exposed women had reduced functioning in attention and digit span (ADS), visual memory span (VMS), and verbal memory recalls (VMR), especially learning ability. We also found a borderline reduction in the Mini-Mental State Examination. The digit symbol, motor, sensory, depression (determined by the Geriatric Depression Scale-Short Form), and activity of daily life were not different between the exposed and reference groups. A significant dose-response relationship was found for VMR, ADS, and VMS.


CONCLUSIONS
Our study showed dose-dependent neurocognitive deficits in certain aspects of attention, visual memory, and learning ability in women previously exposed to PCBs and PCDFs, but not in exposed men.
Lin
Kao-Chang
KC
Department of Neurology, Chi-Mei Medical Center, Tainan, Taiwan.
Guo
Nai-Wen
NW
Tsai
Pei-Chien
PC
Yang
Chiu-Yueh
CY
Guo
YueLiang Leon
YL
D000368:Aged; D001572:Benzofurans / Q000633:toxicity*; D003072:Cognition Disorders / Q000139:chemically induced*; D015331:Cohort Studies; D000072338:Dibenzofurans, Polychlorinated; D004781:Environmental Exposure; D006801:Humans; D008875:Middle Aged; D009422:Nervous System Diseases / Q000139:chemically induced*; D009483:Neuropsychological Tests; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D013624:Taiwan
D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D011078:Polychlorinated Biphenyls