Impact of prenatal chlorpyrifos exposure on neurodevelopment in the first 3 years of life among inner-city children.
Level 3 - non-randomized controlled study
Prospective observational birth cohort study
PubMed 17116700 · doi:10.1542/peds.2006-0338
What was done
This prospective cohort study evaluated the neurodevelopmental effects of prenatal chlorpyrifos exposure in 254 inner-city minority children followed through the first 3 years of life. Chlorpyrifos exposure was measured in umbilical cord plasma. Cognitive and motor development were assessed at 12, 24, and 36 months using the Bayley Scales of Infant Development II, and child behavior was measured at 36 months using the Child Behavior Checklist.
What was found
Children with high prenatal chlorpyrifos exposure (>6.17 pg/g plasma) scored on average 6.5 points lower on the Bayley Psychomotor Development Index (PDI) and 3.3 points lower on the Bayley Mental Development Index (MDI) at 3 years of age compared with those with lower exposure. Adjusted mean 36-month scores differed by 7.1 points for PDI and 3.0 points for MDI. High-exposure children were 5 times more likely to have PDI delay and 2.4 times more likely to have MDI delay, and were significantly more likely to experience attention problems, attention-deficit/hyperactivity disorder problems, and pervasive developmental disorder problems at 3 years of age.
Why it matters
The paper provides prospective human biomarker evidence that prenatal exposure to the organophosphate insecticide chlorpyrifos is linked to measurable cognitive, motor, and behavioral deficits in early childhood.
Limits
The study is observational and restricted to a single inner-city minority cohort of 254 children, limiting broad generalizability. The abstract does not report confidence intervals, exact p-values, or adjustments for other chemical co-exposures.
Cited by
- supports Research by Dr. Virginia Rauh at Columbia University demonstrated that higher levels of chlorpyrifos in umbilical cord blood correlate with lower IQ scores in children at ages 3, 5, and 7.