ASSOCIATIONS BETWEEN CHRONIC LEAD EXPOSURE, INFLAMMATORY PROFILES, AND COGNITION IN CHILDREN LIVING NEAR ABANDONED MINING WASTE

In the Sierra de Huautla Biosphere Reserve (Morelos, Mexico), there is an accumulation of mining waste containing heavy metals like lead (Pb). Chronic Pb exposure affects the central nervous system and the immune system by altering immune cell populations and modulating cytokine expression. Immune activation and Pb exposure may influence brain regions involved in executive functions (EF), particularly working memory (WM), with children being particularly vulnerable. However, the interaction between Pb exposure, immune alterations, and cognitive function in human populations remains poorly understood. This study aimed to assess the effects of chronic Pb exposure on circulating cytokine concentrations, inflammatory profiles, and cognitive performance in children aged 5–11 years living in a rural community of Huautla, Morelos. Pb concentrations were quantified in hair samples using voltammetry. EF and WM were evaluated using the Neuropsychological Battery of Executive Functions and Frontal Lobes. Serum cytokines were measured using a multiplex assay. Results showed significantly higher Pb concentrations in boys (n = 29) compared to girls (n = 40), and boys also exhibited lower WM scores. Linear regression analyses revealed a significant negative association between Pb concentrations and proinflammatory cytokines, suggesting an immunosuppressive effect of long-term Pb exposure. A similar association was observed using a principal component analysis representing an inflammatory profile. In boys, but not in girls, this inflammatory profile was negatively associated with EF scores. Higher Pb concentrations were also associated with poorer performance in WK tasks. These findings suggest that Pb exposure is associated with immune alterations and cognitive deficits.