PCB-related neurodevelopmental deficit may be transient: follow-up of a cohort at 6 years of age

Based on our own findings from a previous study we aimed to establish if cognitive deficit, shown to be induced by perinatal exposure to polychlorinated biphenyls (PCBs) at earlier ages, persists into school-age. Seventy-seven percent of a cohort last examined at 42 months of age using the Kaufman Assessment Battery for Children were reexamined with the same test at 72 months. At this point, and contrary to the results at 30 and 42 months no adverse PCB-effects were found. However, the positive effect of the home environment became even more pronounced. Conclusion: early PCB-exposure at current environmental background levels possibly induces transient delay in cognitive development rather than irreversible deficit.