ABSTRACT
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.
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.
Subject(s)
Humans , Child , Organophosphorus Compounds , Child , Cognition , Pesticide ExposureABSTRACT
Background: Petcoke is a remmant of the oil refiningprocess that contains Ni and other heavy metáis. Undesired human exposure to these compounds may result from petcoke combustión in plants located in the vicinity ofthe cities. Aim: To compare levéis of urinary Ni in schoolchildren residing in cities exposed and not exposed to petcoke pollution. Material and methods: A cross sectional study was done in schoolchildren aged 7 to 8 years oíd in two cities in northern Chile: Mejillones (n = 59), near to a petcoke plant and Tocopilla (n = 56) as the reference city. First, morning urinary samples were collected and urinary Ni was determined by Atomic Absorption Spectrometry. Socioeconomic and environmental exposure information of families was obtained applying a questionnaire to parents. Múltiple linear regression was performed to identify other variables that may explain urinary Ni differences among the cities. Results: Median level of Ni was higher in Mejillones (4.9 fig/L) than in Tocopilla (3.9 fig/L). Residing in the exposed city was the most important explaining factor (B = 0.26; IC 0.107 - 0.428). Additionally years of residency was associated with urinary Ni (B = 0.03; IC 0.004 - 0.060). Conclusions: Urinary Ni in schoolchildren is higher in the city exposed to petcoke emissions. The difference does not imply that there are concrete hazards for the population s health. However, it warns about the existence of a higher exposure in places where petcoke is used.