Polybrominated Diphenyl Ether Exposure and Thyroid Function Tests in North American Adults

Area of Science:

• Environmental Health
• Toxicology
• Endocrinology

Background:

• Polybrominated diphenyl ethers (PBDEs) are widely used flame retardants found in consumer products.
• Animal studies suggest PBDEs disrupt thyroid hormones (THs), but human evidence remains inconclusive.
• This study investigated PBDE exposure and TH levels in North American adults.

Purpose of the Study:

• To estimate associations between serum PBDE concentrations and thyroid hormone levels.
• To analyze repeated measures of PBDEs and THs in a cohort of healthy adult office workers.
• To clarify the impact of PBDE exposure on thyroid function in humans.

Main Methods:

• Collected up to three serum samples from 52 healthy adult office workers in Boston, MA, between 2010-2011.
• Analyzed serum concentrations of PBDE congeners and thyroid hormones (T4, T3, free T4, TSH).
• Utilized multivariable mixed regression models to assess the relationship between PBDEs and THs.

Main Results:

• The predominant PBDE congener detected was BDE-47.
• A 1-ng/g increase in serum BDE-47 was associated with a 2.6-μg/dL decrease in total thyroxine (T4).
• PBDEs showed an inverse association with total T4 but were not strongly linked to T3, free T4, or TSH.

Conclusions:

• Findings align with animal studies indicating PBDE exposure lowers serum T4.
• The lack of association with other thyroid hormones suggests no significant impact on the pituitary-thyroid axis.
• Results suggest PBDEs may interfere with T4 binding to serum proteins.