Predictors of exposure to organophosphate pesticides in schoolchildren in the Province of Talca, Chile.

BACKGROUND Few data exist in Latin America concerning the association between organophosphate (OP) urinary metabolites and the consumption of fruits and vegetables and other exposure risk variables in schoolchildren. METHODS We collected samples of urine from 190 Chilean children aged 6-12 years, fruits and vegetables, water and soil from schools and homes, and sociodemographic data through a questionnaire. We measured urinary dialkylphosphate (DAP) OP metabolites and OP pesticide residues in food consumed by these 190 children during two seasons: December 2010 (summer) and May 2011 (fall). We analyzed the relationship between urinary DAP concentrations and pesticide residues in food, home pesticide use, and residential location. RESULTS Diethylalkylphosphates (DEAP) and dimethylalkylphosphates (DMAP) were detected in urine in 76% and 27% of the samples, respectively. Factors associated with urinary DEAP included chlorpyrifos in consumed fruits (p<0.0001), urinary creatinine (p<0.0001), rural residence (p=0.02) and age less than 9 years (p=0.004). Factors associated with urinary DMAP included the presence of phosmet residues in fruits (p<0.0001), close proximity to a farm (p=0.002), home fenitrothion use (p=0.009), and season (p<0.0001). CONCLUSIONS Urinary DAP levels in Chilean school children were high compared to previously reported studies. The presence of chlorpyrifos and phosmet residues in fruits was the major factor predicting urinary DAP metabolite concentrations in children.