Absorption, distribution, metabolism, and excretion of three [¹⁴C]PBDE congeners in laying hens and transfer to eggs.

Abstract

1. Polybrominated diphenyl ethers (PBDEs) levels in environmental matrices have generally declined following their phaseout as flame retardants.

2. The objective of this study was to determine the absorption, distribution, metabolism, and excretion of three persistent PBDEs in laying hens and their transfer into eggs. Laying hens (n = 4 per congener) received a single oral dose of BDE-99, -153, or -209 and eggs and excreta were collected daily for 7 days, then tissues were collected and analysed.

3. Cumulative BDE-209 excretion was 93% of dose, and bioavailability was approximately 17%. Lesser amounts of BDE-99 (41%) and -153 (26%) were excreted with bioavailabilities of 87% and 79%, respectively. Phenolic metabolites were observed in excreta extracts from BDE-99 dosed birds. Cumulative transfers based on bioavailability of BDE-99, -153, and -209 to eggs were 17%, 34%, and 15%, respectively. Egg residues were primarily present in yolk (12.3%, 23.5%, and 2.1% of the total dose for BDE-99, -153, and -209, respectively). Adipose, skin, ova, intestine, and thigh muscle contained the highest levels of radioactive tissue residues.

4. These studies demonstrate movement of PBDE residues into edible tissues and eggs of laying hens.

Keywords:

• Polybrominated diphenyl ethers (PBDEs)
• laying hens
• chickens
• egg transfer
• ADME

Acknowledgements

We would like to thank Andrew Thompson, David Smith, Jason Holthusen, and Savannah Gray for their assistance during the live-phase and sample collection portions of the study. The use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the United States Department of Agriculture, the Agricultural Research Service, or the Food Safety and Inspection Service of any product or service to the exclusion of others that may be suitable. USDA is an equal opportunity provider and employer.

Disclosure statement

No potential conflict of interest was reported by the author(s).