Exposure to the androgenic brominated flame retardant 1,2-dibromo-4-(1,2-dibromoethyl)-cyclohexane alters reproductive and aggressive behaviors in birds

1,2-Dibromo-4-(1,2-dibromoethyl)cyclohexane (DBE-DBCH; CAS 3322-93-8) is a bioaccumulative isomer of a current-use brominated flame retardant that has been detected in environmental samples. All 4 structural isomers are androgen agonists, however little toxicological information exists for this compound. The objective of this study was to determine if β-DBE-DBCH, the isomer found most prominently in animal tissue, affects androgen-dependent behavior of breeding American kestrels (Falco sparverius). We hypothesized that if β-DBE-DBCH acts as an androgen agonist in kestrels, androgen-dependent behaviors (i.e., copulation, courtship, aggression) would increase and behaviors inhibited by androgens (i.e., parental care behaviors) would decrease. Sixteen captive experimental kestrel pairs were exposed to 0.239 ng β-DBE-DBCH /g kestrel/day by diet from 4 weeks prior to pairing until their nestlings hatched (mean 82 d), and were compared to vehicle-only-exposed control pairs (n = 15). Androgen-dependent behaviors were significantly increased in β-DBE-DBCH-exposed birds, consistent with our hypothesis. These behavioral changes included copulation and other sexual behaviors in males and females and aggression in males, suggesting that β-DBE-DBCH may have acted like an androgen agonist in these birds. Parental behaviors were not reduced in exposed birds as predicted, although dietary exposure had ceased before chicks hatched. Further assessment of β-DBE-DBCH is recommended given these behavioral changes and the previously reported reproductive changes in the same birds. This article is protected by copyright. All rights reserved. Language: en