title: Evaluation of polybrominated diphenyl ethers (PBDEs) in matched cat sera and house dust samples: investigation of a potential link between PBDEs and spontaneous feline hyperthyroidism.
abstract: The cause of feline hyperthyroidism (FH), a common endocrinopathy of domestic cats, is unknown. A potential association between exposure to environmental contaminants polybrominated diphenyl ethers (PBDEs) and FH was investigated. The median serum level for the sum of congeners BDE-47, BDE-99, BDE-153, BDE-154 and BDE-183 (Σ5) in hyperthyroid and euthyroid cats was 82 and 174 ng g(-1)lw respectively with no significant difference in PBDE levels or profiles between groups. Overall, the median (min to max) concentration of PBDEs in cat serum (n=65) was 118 ng g(-1)lw (5-5260 ng g(-1)lw), which is approximately 10 times higher than that observed in the Australian human population. Furthermore, congener composition in feline serum samples was dominated by congener BDE-99, followed by BDE-47 then BDE-153 which differs from results of human biomonitoring. There was no correlation between PBDE levels in feline serum samples and matched house dust samples (n=25). However the similarity of BDE-47/99 ratio in each matrix suggests dust is likely the dominant exposure. Calculation of the daily exposure dose via dust ingestion for cats equated to a mean of 33 ng kg(-1) bw d(-1) (0.2-150 ng kg(-1) bw d(-1)). Differences in exposure estimates for Australian and US cats, based on dust ingestion alone, are consistent with the observed differences in body burdens. Our results do not support a role for PBDE exposure in the aetiopathogenesis of FH.
authors.affiliation: Valentine Charlton Cat Centre, The University of Sydney, Evelyn Williams Building B10, The University of Sydney, NSW 2006, Australia.
authors.forename: K
authors.initials: K
authors.lastname: Chow
authors.affiliation: National Research Centre for Environmental Toxicology, The University of Queensland, 39 Kessels Road, Coopers Plains, QLD 4108, Australia.
authors.forename: L K
authors.initials: LK
authors.lastname: Hearn
authors.affiliation: Gladesville Veterinary Hospital, 449 Victoria Road, Gladesville, NSW 2111, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Zuber
authors.affiliation: Valentine Charlton Cat Centre, The University of Sydney, Evelyn Williams Building B10, The University of Sydney, NSW 2006, Australia.
authors.forename: J A
authors.initials: JA
authors.lastname: Beatty
authors.affiliation: National Research Centre for Environmental Toxicology, The University of Queensland, 39 Kessels Road, Coopers Plains, QLD 4108, Australia.
authors.forename: J F
authors.initials: JF
authors.lastname: Mueller
authors.affiliation: Valentine Charlton Cat Centre, The University of Sydney, Evelyn Williams Building B10, The University of Sydney, NSW 2006, Australia.
authors.forename: V R
authors.initials: VR
authors.lastname: Barrs
mesh_terms: D000818:Animals; D002415:Cats; D004391:Dust; D055768:Halogenated Diphenyl Ethers / Q000097:blood* / Q000633:toxicity; D006980:Hyperthyroidism / Q000139:chemically induced*
chemical_list: D004391:Dust; D055768:Halogenated Diphenyl Ethers
keywords: Exposure; Feline hyperthyroidism; Polybrominated diphenyl ether