Alterations in thyroid hormone status in Greenland sledge dogs exposed to whale blubber contaminated with organohalogen compounds.
As a model of high trophic level carnivores, sledge dogs were fed from 2 to 18 months of age with minke whale blubber containing organohalogen compounds (OHC) corresponding to 128 μg PCB/day. Controls were fed uncontaminated porcine fat. Thyroid hormone levels were assessed in 7 exposed and 7 control sister bitches (sampled at age 6-18 months) and 4 exposed and 4 control pups, fed the same diet as their mothers (sampled age 3-12 months). Lower free and total T3 and T4 were seen in exposed vs. control bitches beyond 10 months of age, and total T3 was lower through 3-12 months of age in exposed pups. A negative correlation with thyroid gland weight was significant for ΣDDT, as was a positive association with total T3 for dieldrin. This study therefore supports observational data that OHCs may adversely affect thyroid functions, and it suggests that OHC exposure duration of 10 months or more may be required for current OHC contamination levels to result in detectable adverse effects on thyroid hormone dynamics.
Kirkegaard
Maja
M
Department of Environmental Medicine, Institute of Public Health, University of Southern Denmark, J.B.Winsløvsvej 17, DK-5000 Odense, Denmark. majakirkegaard@yahoo.dk
Sonne
Christian
C
Dietz
Rune
R
Letcher
Robert J
RJ
Jensen
Asger L
AL
Hansen
Signe Stige
SS
Jenssen
Bjørn Munro
BM
Grandjean
Philippe
P
D000821:Animal Feed; D000818:Animals; D004026:Dieldrin / Q000378:metabolism / Q000633:toxicity; D004285:Dogs; D052244:Endocrine Disruptors / Q000378:metabolism / Q000633:toxicity*; D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D005506:Food Contamination; D006116:Greenland; D006846:Hydrocarbons, Halogenated / Q000378:metabolism / Q000633:toxicity*; D008297:Male; D011078:Polychlorinated Biphenyls / Q000378:metabolism / Q000633:toxicity; D013961:Thyroid Gland / Q000187:drug effects* / Q000378:metabolism; D013963:Thyroid Hormones / Q000378:metabolism*; D013974:Thyroxine / Q000378:metabolism; D013997:Time Factors; D014907:Whales / Q000378:metabolism*
D052244:Endocrine Disruptors; D006846:Hydrocarbons, Halogenated; D013963:Thyroid Hormones; D011078:Polychlorinated Biphenyls; D004026:Dieldrin; D013974:Thyroxine