Neuropsychological effects of chronic low-dose exposure to polychlorinated biphenyls (PCBs): a cross-sectional study.
BACKGROUND
Exposure to indoor air of private or public buildings contaminated with polychlorinated biphenyls (PCBs) has raised health concerns in long-term users. This exploratory neuropsychological group study investigated the potential adverse effects of chronic low-dose exposure to specific air-borne low chlorinated PCBs on well-being and behavioral measures in adult humans.


METHODS
Thirty employees exposed to indoor air contaminated with PCBs from elastic sealants in a school building were compared to 30 non-exposed controls matched for education and age, controlling for gender (age range 37-61 years). PCB exposure was verified by external exposure data and biological monitoring (PCB 28, 101, 138, 153, 180). Subjective complaints, learning and memory, executive function, and visual-spatial function was assessed by standardized neuropsychological testing. Since exposure status depended on the use of contaminated rooms, an objectively exposed subgroup (N = 16; PCB 28 = 0.20 microg/l; weighted exposure duration 17.9 +/- 7 years) was identified and compared with 16 paired controls.


RESULTS
Blood analyses indicated a moderate exposure effect size (d) relative to expected background exposure for total PCB (4.45 +/- 2.44 microg/l; d = 0.4). A significant exposure effect was found for the low chlorinated PCBs 28 (0.28 +/- 0.25 microg/l; d = 1.5) and 101 (0.07 +/- 0.09 microg/l; d = 0.7). Although no neuropsychological effects exceeded the adjusted significance level, estimation statistics showed elevated effect sizes for several variables. The objectively exposed subgroup showed a trend towards increased subjective attentional and emotional complaints (tiredness and slowing of practical activities, emotional state) as well as attenuated attentional performance (response shifting and alertness in a cued reaction task).


CONCLUSIONS
Chronic inhalation of low chlorinated PCBs that involved elevated blood levels was associated with a subtle attenuation of emotional well-being and attentional function. Extended research is needed to replicate the potential long-term low PCB effects in a larger sample.
Peper
Martin
M
Charité Universitätsmedizin Berlin, Institute of Pharmacology and Toxicology (CCM), Dorotheenstr. 94, 10117 Berlin, Germany. peper@psychologie.uni-freiburg.de
Klett
Martin
M
Morgenstern
Rudolf
R
D000328:Adult; D000395:Air Pollutants, Occupational / Q000097:blood / Q000633:toxicity*; D016902:Air Pollution, Indoor / Q000009:adverse effects* / Q000032:analysis; D001288:Attention / Q000187:drug effects*; D003430:Cross-Sectional Studies; D004784:Environmental Monitoring; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D016273:Occupational Exposure / Q000032:analysis*; D011078:Polychlorinated Biphenyls / Q000097:blood / Q000633:toxicity*; D012574:Schools; D017678:Sex Distribution; D011795:Surveys and Questionnaires
D000395:Air Pollutants, Occupational; D011078:Polychlorinated Biphenyls