Individual characteristics associated with PBDE levels in U.S. human milk samples

Area of Science:

• Environmental Health
• Toxicology
• Human Exposure Assessment

Background:

• Polybrominated diphenyl ethers (PBDEs) are flame retardants with higher reported concentrations in US human samples compared to Europe and Asia.
• Factors influencing individual variability in PBDE body burden remain largely unknown.

Purpose of the Study:

• To measure PBDE concentrations in US human milk from 2004-2006.
• To assess maternal characteristics associated with PBDE concentrations and changes in concentration between 3 and 12 months postpartum.

Main Methods:

• Analysis of 303 human milk samples at 3 months postpartum for PBDEs.
• Analysis of a second sample from 83 women at 12 months postpartum.
• Generalized linear models used to evaluate PBDE concentrations and variability by maternal age, parity, and prepregnancy body mass index (BMI).

Main Results:

• PBDE congeners BDEs 28, 47, 99, 100, and 153 detected in over 70% of samples, with BDE-47 being the most abundant.
• PBDE concentrations were lower in mothers over 34 years old and higher in mothers with high BMI compared to normal BMI.
• PBDE concentrations in milk showed high variability between 3 and 12 months postpartum, with a median increase of 14%.

Conclusions:

• PBDEs are nearly ubiquitous in human milk samples analyzed.
• Maternal age and BMI are significant factors associated with PBDE concentrations in human milk.
• PBDE levels in human milk exhibit considerable variability throughout the lactation period.