Although Polychlorinated Biphenyls have been banned in the United States since 1979, University of Montreal and CHU Sainte-Justine researcher Maryse Bouchard has found that higher levels of the toxin was associated with lower cognitive performance in seniors. There is a significant association between PCB levels and cognitive abilities among individuals aged 70 to 84 years; the correlation was also detected to a lesser extent among people aged 60-69 years. This analysis also showed that the association differed by sex. Women in the older age group had the largest diminution in cognition in relation to exposure. "While most studies have looked at the impact of PCBs on infant development, our research shows that this toxin might affect us throughout our lives," Bouchard said.