title: Investigating endocrine and physiological parameters of captive American kestrels exposed by diet to selected organophosphate flame retardants.
abstract: Organophosphate triesters are high production volume additive flame retardants (OPFRs) and plasticizers. Shown to accumulate in abiotic and biotic environmental compartments, little is known about the risks they pose. Captive adult male American kestrels (Falco sparverius) were fed the same dose (22 ng OPFR/g kestrel/d) daily (21 d) of tris(2-butoxyethyl) phosphate (TBOEP), tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP), or tris(1,2-dichloro-2-propyl) phosphate (TDCIPP). Concentrations were undetected in tissues (renal, hepatic), suggesting rapid metabolism. There were no changes in glutathione status, indicators of hepatic oxidative status, or the cholinergic system (i.e., cerebrum, plasma cholinesterases; cerebrum muscarinic, nicotinic receptors). Modest changes occurred in hepatocyte integrity and function (clinical chemistry). Significant effects on plasma free triiodothyronine (FT3) concentrations occurred with exposure to TBOEP, TCEP, TCIPP, and TDCIPP; TBOEP and TCEP had additional overall effects on free thyroxine (FT4), whereas TDCIPP also influenced total thyroxine (TT4). Relative increases (32%-96%) in circulating FT3, TT3, FT4, and/or TT4 were variable with each OPFR at 7 d exposure, but limited thereafter, which was likely maintained through decreased thyroid gland activity and increased hepatic deiodinase activity. The observed physiological and endocrine effects occurred at environmentally relevant concentrations and suggest parent OPFRs or metabolites may have been present despite rapid degradation.
authors.forename: Kimberly J
authors.initials: KJ
authors.lastname: Fernie
authors.affiliation: ‡Stantec Consulting Ltd., 386 Broadway Avenue, Winnipeg, MB, Canada R3C 3R6.
authors.forename: Vince
authors.initials: V
authors.lastname: Palace
authors.affiliation: ‡Stantec Consulting Ltd., 386 Broadway Avenue, Winnipeg, MB, Canada R3C 3R6.
authors.forename: Lisa E
authors.initials: LE
authors.lastname: Peters
authors.affiliation: §McGill University, 21,111 Lakeshore Road, Ste Anne de Bellevue, PQ, Canada H9X 3V9.
authors.forename: Nil
authors.initials: N
authors.lastname: Basu
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Letcher
authors.affiliation: ⊥U.S. Geological Survey, Patuxent Wildlife Research Center, BARC East Building 308, 10300 Baltimore Avenue, Beltsville, Maryland 20705, United States.
authors.forename: Natalie K
authors.initials: NK
authors.lastname: Karouna-Renier
authors.affiliation: ⊥U.S. Geological Survey, Patuxent Wildlife Research Center, BARC East Building 308, 10300 Baltimore Avenue, Beltsville, Maryland 20705, United States.
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Schultz
authors.affiliation: ⊥U.S. Geological Survey, Patuxent Wildlife Research Center, BARC East Building 308, 10300 Baltimore Avenue, Beltsville, Maryland 20705, United States.
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Lazarus
authors.affiliation: ⊥U.S. Geological Survey, Patuxent Wildlife Research Center, BARC East Building 308, 10300 Baltimore Avenue, Beltsville, Maryland 20705, United States.
authors.forename: Barnett A
authors.initials: BA
authors.lastname: Rattner
mesh_terms: D000818:Animals; D004032:Diet; D004703:Endocrine System / Q000187:drug effects / Q000378:metabolism*; D004781:Environmental Exposure / Q000032:analysis*; D046093:Falconiformes / Q000097:blood / Q000502:physiology*; D005411:Flame Retardants / Q000633:toxicity*; D008297:Male; D009943:Organophosphorus Compounds / Q000633:toxicity*; D013963:Thyroid Hormones / Q000097:blood; D014481:United States
chemical_list: D005411:Flame Retardants; D009943:Organophosphorus Compounds; D013963:Thyroid Hormones