Exposición a organofosforados y desempeño cognitivo en escolares rurales chilenos: un estudio exploratorio / Exposure to organophosphate and cognitive performance in chilean rural school children: an exploratory study

RESUMEN

OBJETIVO: evaluar la presencia de metabolitos organofosforados en la orina de escolares rurales y estimar la asociación con el desempeño cognitivo. METODOLOGIA: estudio exploratorio de diseño transversal. Se midió en 25 niños el funcionamiento cognitivo con el test de inteligencia WISC-III y concentraciones de metabolitos organofosforados en orina. RESULTADOS: 56% de los niños presentaron concentraciones sobre el límite de detección para el dimetilfosfato (DMP) y el dimetiltiofosfato (dmtp), y 92% presentó el metabolito dietilfosfato (dep) sobre este límite. En el WISC-III,el coeficiente intelectual (ci) bajo el promedio (CI > 90) corresponde a CI total = 60%; CIejecución = 64%; CIverbal = 52%; CI organización perceptual = 60%; CIvelocidad de procesamiento = 95%; y CI ausencia de distractibilidad = 64%. Se encontró una asociación inversa entre el factor velocidad de procesamiento y el dmtp (rs = -0,44, p = 0,014). CONCLUSIONES: los resultados indican exposición a plaguicidas organofosforados en escolares rurales medidos con biomarcadores de metabolitos organofosforados en orina. Se observó relación entre la presencia de un metabolito organofosforado y un factor de desempeño cognitivo de la prueba WISC-III. Se considera pertinente evaluar los efectos de la presencia de metabolitos organofosforados en el funcionamiento cognitivo en una muestra mayor, considerando otras variables de exposición.

ABSTRACT

OBJECTIVE: to evaluate the presence of organophosphate metabolites (OP) in the urine of rural schoolchildren and estimate its association with their cognitive performance. METHODOLOGY: a cross-sectional exploratory study in which a total of 25 children were assessed. Cognitive functioning was measured using the WISC-III intelligence test. Additionally, the concentration of OP metabolites in their urine was tested. RESULTS: 56% of the children had concentration levels above the detection limit for dimethylphosphate (DMP) and dimethyltiophosphate (DMTP). Moreover, 92% of them had the metabolite diethylphosphate (DEP) values on this limit. Regarding the WISC-III, the intelligence quotient (IQ) values below the average (IQ > 90) correspond to Total IQ = 60% performance IQ = 64%, verbal IQ = 52%, perceptual organization IQ = 60%, processing speed IQ = 95%, and freedom from distractibility IQ = 64%. An inverse association was found between the processing speed factor and DMTP (r s = -0.44, p = 0.014). CONCLUSIONS: results indicate that the rural schoolchildren whose urine was measured with OP metabolite biomarkers had been exposed to OP pesticides. A relationship was observed between the presence of OP metabolites and the cognitive performance factor of the WISC-III test. We believe it is appropriate to evaluate the effects of the presence of OP metabolites on cognitive functioning in a larger sample, while considering other exposure variables.