Avian metabolism of halogenated biphenyls

1. The metabolism of several halogenated biphenyls has been studied using poultry as a model system. The substrates 4-chlorobiphenyl and 4-bromobiphenyl each yielded two metabolites (4'chloro-4-biphenylol, 4'chloro-3,4-biphenyldiol; 4'bromo-4-biphenylol, 4'bromo-3,4-biphenyldiol), while 4,4'dichlorobiphenyl yielded only one metabolite (4,4'dichloro-3-biphenylol). 2. Metabolites were not found in eggs collected for 7 days following the administration of the substrate.