OBJECTIVE: Recent pesticide-monitoring results suggest that a shift in residential pesticide exposure from organophosphorus insecticides to pyrethroid insecticides has occurred. Pyrethroid insecticides are potential neurodevelopmental toxicants and have not been evaluated for developmental toxicity. Our objective was to explore the association between prenatal exposure to permethrin (acommonpyrethroid) and piperonyl butoxide (a pyrethroid synergist) and 36-month neurodevelopment.
METHODS: Participants is this study were part of a prospective cohort of black and Dominican mothers and newborns living in low-income neighborhoods in New York City. We examined 36-month cognitive and motor development (using the Bayley Scales of Infant Development, second edition) as a function of permethrin levels measured in maternal
and umbilical cord plasma collected on delivery and permethrin and piperonyl butoxide levels in personal air collected during pregnancy. All models were controlled for gender, gestational age, ethnicity, maternal education, maternal intelligence, quality of the home environment, and prenatal exposure to environmental tobacco smoke and chlorpyrifos.
RESULTS: Prenatal exposure to permethrin in personal air and/or plasma was not associated with performance scores for the Bayley Mental Developmental Index or the Psychomotor Developmental Index. After data adjustment, children more highly exposed to piperonyl butoxide in personal air samples (>4.34 ng/m3) scored 3.9 points lower on the Mental Developmental Index than those with lower exposures (95% confidence interval: -0.25 to -7.49).
CONCLUSIONS: Prenatal exposure to piperonyl butoxide was negatively associated with 36-month neurodevelopment.