Format

Send to

Choose Destination
See comment in PubMed Commons below
Environ Health Perspect. 2009 Sep;117(9):1380-6. doi: 10.1289/ehp.0900633. Epub 2009 May 12.

Thyroid function and plasma concentrations of polyhalogenated compounds in Inuit adults.

Author information

1
Public Health Research Unit, Centre hospitalier universitaire de Québec-CHUL, 2875 boulevard Laurier Edifice Delta, Québec, Canada.

Abstract

BACKGROUND:

Several ubiquitous polyhalogenated compounds (PHCs) have been shown to alter thyroid function in animal and in vitro studies. So far, epidemiologic studies have focused on the potential effect of a small number of them, namely, polychlorinated biphenyls (PCBs) and some organochlorines (OCs), without paying attention to other important PHCs.

OBJECTIVES:

We investigated the relationship between exposure to several PHCs and thyroid hormone homeostasis in Inuit adults from Nunavik.

METHODS:

We measured thyroid parameters [thyroid-stimulating-hormone (TSH), free thyroxine (fT(4)), total triiodothyronine (tT(3)), and thyroxine-binding globulin (TBG)] and concentrations of 41 contaminants, including PCBs and their metabolites, organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), perfluorooctanesulfonate (PFOS), and a measure of dioxin-like compounds, detected in plasma samples from Inuit adults (n = 623).

RESULTS:

We found negative associations between tT(3) concentrations and levels of 14 PCBs, 7 hydroxylated PCBs (HO-PCBs), all methylsulfonyl metabolites of PCBs (MeSO(2)-PCBs), and 2 OCPs. Moreover, we found negative associations between fT(4) levels and hexachlorobenzene concentrations. TBG concentrations were inversely related to 8 PCBs, 5 HO-PCBs, and 3 OCPs. Exposure to BDE-47 was positively related to tT (3), whereas PFOS concentrations were negatively associated with TSH, tT(3,) and TBG and positively with fT(4) concentrations.

CONCLUSION:

Exposure to several PHCs was associated with modifications of the thyroid parameters in adult Inuit, mainly by reducing tT(3) and TBG circulating concentrations. The effects of PFOS and BDE-47 on thyroid homeostasis require further investigation because other human populations display similar or higher concentrations of these chemicals.

KEYWORDS:

Inuit; dioxin-like compounds; hydroxylated metabolites; organochlorines; perfluoro-octanesulfonate; polybrominated diphenyl ethers; polychlorinated biphenyls; polyhalogenated compounds; thyroid hormones

PMID:
19750101
PMCID:
PMC2737013
DOI:
10.1289/ehp.0900633
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for National Institute of Environmental Health Sciences Icon for PubMed Central
    Loading ...
    Support Center