Polychlorinated Biphenyls, Oxidative Stress, and Brain Health: Mechanistic Links to Neurodegenerative and Neurodevelopmental Diseases

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that remain widely detectable in the environment and human tissues decades after their ban, raising concerns for brain health. Both dioxin-like (DL) and non-dioxin-like (NDL) congeners interfere with neuronal function through partially distinct pathways, including aryl hydrocarbon receptor activation, disruption of calcium and dopaminergic signaling, oxidative stress, and epigenetic remodeling. Experimental and epidemiological studies indicate that developmental PCB exposure is associated with impaired cognition, attention, motor function, and increased risk of neurodevelopmental disorders. Furthermore, chronic exposure in adulthood has been linked to neurodegenerative diseases. At the cellular level, NDL-PCBs sensitize ryanodine receptors, alter dendritic and axonal growth, promote mitochondrial dysfunction, generate reactive oxygen and nitrogen species, and compromise blood–brain barrier integrity, thereby fostering neuroinflammation, synaptic dysfunction, and neuronal loss. This review synthesizes current evidence on the molecular and cellular mechanismtable s underlying PCB-induced neurotoxicity across the lifespan, highlighting oxidative stress as a central factor, integrating calcium dysregulation, neurotransmitter imbalance, and apoptotic and epigenetic pathways. Finally, potential neuroprotective roles of antioxidant strategies are discussed, emphasizing their relevance for mitigating PCB-related neurodevelopmental and neurodegenerative risk.