Lactational exposure to polybrominated diphenyl ethers and its relation to social and emotional development among toddlers.
BACKGROUND
Polybrominated diphenyl ethers (PBDEs) have been widely used as flame retardants and are ubiquitous environmental contaminants. PBDEs have been linked to adverse neurodevelopment in animals and humans.


OBJECTIVE
We investigated the association between breast milk PBDE levels and social and emotional development in toddlers.


METHODS
The Pregnancy Infection and Nutrition (PIN) and PIN Babies studies followed a cohort of North Carolina pregnant women and their children through 36 months of age. Breast milk samples obtained at 3 months postpartum were analyzed for PBDEs. The Infant-Toddler Social and Emotional Assessment (ITSEA) was completed by mothers when children were approximately 30 months of age (n = 222). We assessed the relationship between breast milk concentrations of five PBDE congeners-BDEs 28, 47, 99, 100, and 153-and children's social and emotional development, adjusting for other factors.


RESULTS
A small, imprecise, yet consistent positive association was apparent between BDEs 47, 99, and 100 and increased externalizing behaviors, specifically activity/impulsivity behaviors. Externalizing domain T-scores ranged from 30 to 87 with a mean of 47.8. Compared with those with BDE-47 concentrations below the median, adjusted externalizing behavior domain scores were 1.6 [95% confidence interval (CI): -1.2, 4.4] and 2.8 (95% CI -0.1, 5.7) points higher for children born to women with breast milk concentrations in the 3rd and 4th quartiles, respectively. PBDEs were not associated with other social and emotional developmental domains.


CONCLUSIONS
Our results, although imprecise, suggest a subtle association between early-life PBDE exposure and increased activity/impulsivity behaviors in early childhood. Confirmation of these results is needed in other longitudinal studies.
University of North Carolina Gillings School of Global Public Health, Chapel Hill, North Carolina 27599, USA.
Kate
K
Hoffman
Margaret
M
Adgent
Barbara Davis
BD
Goldman
Andreas
A
Sjödin
Julie L
JL
Daniels
D002652:Child Behavior / Q000187:drug effects*; D002653:Child Behavior Disorders / Q000139:chemically induced* / Q000453:epidemiology; D002657:Child Development / Q000187:drug effects*; D002675:Child, Preschool; D015331:Cohort Studies; D004644:Emotions / Q000187:drug effects; D004781:Environmental Exposure; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D005411:Flame Retardants / Q000633:toxicity*; D055768:Halogenated Diphenyl Ethers / Q000633:toxicity*; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D008895:Milk, Human / Q000737:chemistry*; D009657:North Carolina / Q000453:epidemiology; D011446:Prospective Studies; D012919:Social Behavior; D011795:Surveys and Questionnaires
D004785:Environmental Pollutants; D005411:Flame Retardants; D055768:Halogenated Diphenyl Ethers