Pyrethroid exposure, attention and executive function in 6-year old children from the Infants′ Environmental Health Study (ISA)

Abstract

OPS 55: Pesticides and neurological outcomes, Room 412, Floor 4, August 26, 2019, 1:30 PM - 3:00 PM Background: Pyrethroid insecticides may impair children’s neurodevelopment but little evidence from prospective studies is available. In Costa Rica, pyrethroids are widely used for vector control. We examined whether prenatal and current pyrethroid exposure was associated with impaired attention and executive function in children from the Infants Environmental Health Study (ISA). Methods: To evaluate attention and executive function, we applied the Conners Continuous Performance Test (CPT-II) and Dimensional Change Card Sort (DCCS in 6-year old children (mean 6.4 ± 0.4 years) (n=268). We obtained repeated urine samples during pregnancy and 5-6 years of age, determined 3-(2,2-dichlorovinyl)-2,2-dimethyl-cyclopropanecarboxylicacid (DCCA) and 3-phenoxybenzoicacid(3-PBA), and summed concentrations of both. We subsequently ran separate linear regression models for log-10 transformed mean prenatal, and mean child metabolite concentrations and CPT-II, and ran separate logistic regression model for DCCS. We adjusted a priori for child age, child sex, HOME score, and maternal education. We also ran analysis stratified by sex. Results: Median (p25-p75) prenatal and current specific gravity-adjusted summed DCCA and 3PBA were 2.4 (1.3-3.9) µg/L and 6.4 (3.8-10.5) µg/L, respectively. Prenatal summed DCCA and 3PBA concentrations were associated with increased CPT-II T-scores of error commissions for boys (ß= 4.5, 95%CI -0.1, 9.1, per ten-fold increase in exposure), but not for girls (ß= -5.1, 95%CI -11.9, 1.8), or all children (1.6, 95%CI -2.3, 5.6). Prenatal summed DCCA and 3PBA were associated with lower scores of DCCS for all children (OR=0.25; 95% 0.1-0.9). Current DCCA and 3PBA concentrations were not associated with measures of attention or executive function.Conclusion: Children aged six years with higher prenatal exposure to pyrethroids had poorer executive function as compared to children with lower prenatal exposure. Boys with higher prenatal exposure also had poorer attention, whereas girls did not. Prenatal exposure to pyrethroid may affect children’s neurodevelopment, some effects may be stronger in boys.