Flame Retardant Linked to Decreased Thyroid Hormone Levels in Pregnant Women
Brenda Eskenazi, Ph.D., Kim Harley, Ph.D., and Asa Bradman, Ph.D.,
University of California Berkeley
NIEHS Grants R01ES015572 and P01ES009605
In the largest study conducted to date, researchers at the University of California Berkeley report that exposure to flame retardant compounds is associated with decreased levels of thyroid stimulating hormone around the beginning of the third trimester of pregnancy. The risk of sub-clinical hyperthyroidism was also associated with exposure.
Polybrominated diphenyl ethers or PBDEs are used as flame retardants in a variety of products including textiles, furniture, automobiles, airplanes, and electronics. PBDEs are lipophilic and bioaccumulate in wildlife and humans and also biomagnify up the food chain. They are found in almost all human beings on earth and their concentration in human serum and breast milk has increased exponentially in the last three decades. They are persistent compounds with half-lives ranging from two to twelve years.
The research team measured PBDE and thyroid hormone levels in 270 pregnant women, most of whom were Mexican American. Lab analyses showed that women with higher levels of PBDEs had lower levels of thyroid stimulating hormone.
These findings are important because of the important role that maternal thyroid hormone levels play in fetal development. Future studies planned by the team will examine whether subclinical hyperthyroidism and maternal exposure to PBDEs are associated with adverse pregnancy outcomes such as preeclampsia, premature birth and low birth weight.
Citation: Chevrier J, Harley KG, Bradman A, Gharbi M, Sjödin A, Eskenazi B. Polybrominated Diphenylether (PBDE) Flame Retardants and Thyroid Hormone during Pregnancy. Environ Health Perspect. 2010 Jun 21.
▲ Up: Carbon Nanotubes Can Affect the Lining of the Lungs (http://www.niehs.nih.gov/research/supported/sep/2009/carbon/index.cfm)
▼ Down: Asthma Symptoms in Children Associated with Acetaminophen Use During Pregnancy (http://www.niehs.nih.gov/research/supported/sep/2010/acetaminophen/index.cfm)
