Particle size fractionation and human exposure of polybrominated diphenyl ethers in indoor dust from Chicago

Abstract

The objective of this study was to investigate the concentration level, the mass distribution based on dust particle size, and the associated human exposure of polybrominated diphenyl ethers (PBDEs) in indoor dust. The total concentration of 13 PBDEs Σ₁₃(BDEs) was found to be 500–6,944 ng/g in indoor dusts, 4,000 ng/g in car interior dust, 260–300 ng/g in outdoor ambient air particles, 30 ng/g in carpet fibers, and as high as 0.5% in carpet padding. Selected dust samples were fractionated based on particle size, and over 80% of the Σ₁₃BDEs were associated with particles < 150 μm in diameter. Mass ratios of BDE206/BDE209 are higher in both indoor and outdoor samples than in commercial deca products; and mass ratio BDE47/BDEs(85+99+100) was much higher in outdoor than in indoor samples. Using EPA software ProUCL, the exposure of Americans to PBDEs via hand-to-mouth transfer of house dust was estimated under the central tendency exposure and reasonable maximum exposure scenarios. The results suggest that ingestion of PBDE-laden house dust via hand-to-mouth contact is likely a significant exposure pathway, especially for children.

Keywords:

• Polybrominated diphenyl ethers
• indoor dust
• particle size
• exposure assessment

Acknowledgments

This study was funded by the U.S. Centers for Disease Control and Prevention (Grant # 1 T01 CD000189-02).

Notes

*The sum of 9 PBDE congeners including BDEs 28, 47, 66, 85, 99, 100, 153, 154, and 183.

^a Number of dust samples.

^b Number of congeners included in the study. Note: Major congeners (BDEs 47, 99, 100, 153, 154 and 209) were included in all studies.

^c Used for daily PBDE intake estimation for Americans (see text). Note: Two U.S. studies were not included due to the lack of sample-specific data.

^a Values from USEPA recommended indoor soil-to-skin adherence factor under CTE and RME scenarios

^b The area of 3 fingers as the total contact area for each event

^c Assuming 50% of the residues on the fingers transferred to the mouth

^d 2 weeks considered as the vacation period and deducted from the total days of a year.