Prenatal PCB exposure and neonatal behavioral assessment scale (NBAS) performance

We examined the relationship between prenatal (cord blood) polychlorinated biphenyls (PCBs) and Neonatal Behavioral Assessment Scale (NBAS) performanc e in babies born to women who consumed contaminated Lake Ontario fish. Cord blood PCBs, DDE, HCB, Mirex, lead, and hair mercury levels were determined for 152 women who reported never consuming Lake Ontario fish and 141 women who reported consuming at least 40 PCB-equivalent Ibs. of Lake Ontario fis h over their lifetime. Earlier work demonstrated that the newborns of fish eaters are exposed to a more heavily chlorinated distribution of PCB congen ers, and that highly chlorinated PCBs (hepta-, octa-, and nonachlorinated b iphenyls) are most strongly correlated with breast mill; levels, perhaps pr oviding the best index of PCB exposure in the Oswego cohort. Given the abov e, one would predict that these PCBs would be related to impaired performan ce on those NBAS clusters associated with fish consumption; namely Habituat ion, Autonomic, and Reflex clusters of the NBAS. Excepting the Relex cluste r, these predictions were confirmed. Results revealed significant linear re lationships between the most heavily chlorinated PCBs and performance impai rments on the Habituation and Autonomic clusters of the NBAS at 25-48 h aft er birth. Additionally, higher prenatal PCB exposure was associated with a nonspecific performance impairment on the NBAS as evidenced by a significan tly greater proportion of NBAS scales in which poor performance was exhibit ed (more than 1 standard deviation below the mean) in the most highly expos ed neonates. Moreover, PCBs of lighter chlorination were unrelated to NBAS performance, as were DDE, Mirex, HCB, lead, and mercury. These results corr oborate our earlier findings linking Lake Ontario fish consumption to the m ost heavily chlorinated PCB congeners, and suggest that the chlorination an d persistence of PCBs may be an important factor both for exposure assessme nt and for determining relationships with neurobehavioral functions. (C) 19 99 Elsevier Science Inc. All rights reserved.