|SINGH,, ANURADHA - Weaver Labs|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2019
Publication Date: N/A
Technical Abstract: Introduction: Most congeners of the PBDE family are showing clear declines in the environment and biota following their discontinuance; however one specific member, i.e., BDE-153, a hexabromo-BDE, in many cases has not declined, particularly in human and cow milk, as well as eggs. The objective of this study is to determine the pharmacokinetics of three important persistent PBDE congeners (BDEs-99, -153, -209) in a food producing animal, i.e. a laying chicken, and the extent of transfer of these congeners into eggs. Materials and Methods: 14C-Radiolabeled BDEs were orally administered to 4 sets of 4 hens. Control birds were dosed in an identical manner except that the capsules contained corn oil, but no BDE. Dosing occurred in the morning of study Day 0. Eggs and excreta were collected daily (on study Days 1 to 7). On Day 7 chickens were euthanized and tissues harvested. Radioactivity in tissues and excreta were measured by tissue combustion of air-dried aliquots. Select tissues and excreta were solvent extracted, extracts chromatographed by TLC, and isolated metabolites analyzed by GC-MS. Results and Discussion: Cumulative BDE-209 excretion was >93% of dose, and suggested lack of intestinal absorption. BDE-99 and -153 were eliminated to a far lesser degree, i.e. 42 and 27%, respectively, and metabolites were observed in fecal extracts of BDE-99, possibly hydroxylated. Metabolites were purified and characterized by GC-MS. PBDE transfer to eggs was observed for all congeners, however, transfer levels were vastly different. Less than 1% of BDE-209 was found in eggs at Day 7, while 17% and 29% of BDE-99 and -153, respectively, were found in eggs. Most of the egg transfer for all congeners was observed in the yolk, although levels could also be detected in white and shell. Determination of other tissue levels of dosed PBDE is on-going. Conclusion: These studies provided data on PBDE pharmacokinetics in a food producing animal and demonstrated that these compounds have different levels of intestinal absorption and metabolism. Furthermore, the data provide some evidence for the chronically high levels of BDE-153 despite worldwide bans on their production and use.