8291349 Cognitive effects of chronic organophosphate exposure on executive function in workers from Maule Region, Chile

<h3>Objective</h3> This study aimed to evaluate the association between chronic exposure to organophosphate pesticides and executive function performance in rural Chilean agricultural workers, using validated neuropsychological assessment and biomarker-based exposure quantification. <h3>Material and Methods</h3> We conducted a longitudinal study (2022–2023) in the Maule region of Chile, comparing agricultural workers with documented occupational pesticide exposure to non-exposed rural controls. Participants (N=80) underwent urine sampling across high and low pesticide seasons to quantify six dialkyl phosphate (DAP) metabolites as biomarkers of organophosphate exposure. Executive function was assessed with the Ineco Frontal Screening (IFS), a validated battery covering working memory, inhibitory control, abstraction, and flexibility. Data were analyzed using multiple linear regressions and generalized estimating equations (GEEs), controlling for age, sex, and education. <h3>Results</h3> Urinary metabolite levels did not differ significantly between groups; however, within-group analyses revealed meaningful dose-response relationships. In the exposed group, higher levels of diethyl metabolites were significantly associated with lower IFS scores in both years (β = -73.61 and -79.20, p &lt; .01). GEEs across years found small but significant negative effects of dimethyl metabolites on IFS performance (β = -0.0858, p &lt; .001), although this effect was sensitive to outlier exclusion. Education and age remained strong predictors of executive function, but the pesticide effects persisted after adjustment. <h3>Conclusion</h3> Findings suggest that chronic organophosphate exposure is associated with modest but consistent impairments in executive function among rural Chilean workers, even in the absence of significant between-group differences in exposure levels. This highlights the potential impact of environmental and dietary sources of exposure and supports the need for stronger regulation and longitudinal monitoring in low-to-middle-income countries.