Mixture of organic pollutants is associated with cognitive aging

INTRODUCTION Environmental organic pollutants impact brain function and cognitive aging, but the effects of real-world complex mixtures of these pollutants is unexplored. METHODS Using data collected at two time points from 170 cognitively normal adults, we used hierarchical Bayesian kernel machine regression to examine the association between joint exposure to 49 organic pollutants and latent variables, derived from neuropsychological tests, that capture key aspects of cognitive aging. RESULTS We observed a non-linear, inverted U-shaped relationship between the pollutant mixture and the global cognitive score. Polychlorinated biphenyls (PCBs) were the most important pollutant group in the mixture followed by industrial-use pollutants. DISCUSSION Exposure to a mixture of organic pollutants was associated with poor cognitive aging. Even though many of these pollutants, like PCBs, have been banned for decades, they persist in our environment. Strategies to reduce exposure to these organic pollutants are needed to minimize their impact on cognitive aging.