By Robert Preidt
MONDAY, May 6 (HealthDay News) -- Exposure to flame-retardant chemicals in the womb is associated with hyperactivity and lower intelligence in children, a new study indicates.
Researchers examined the effects of polybrominated diphenyl ethers (PBDEs), which were used for decades as fire retardants in common products such as carpeting, baby strollers and electronics.
"In animal studies, PBDEs can disrupt thyroid hormone and cause hyperactivity and learning problems. Our study adds to several other human studies to highlight the need to reduce exposure to PBDEs in pregnant women," study author Dr. Aimin Chen, an assistant professor in the department of environmental health at the University of Cincinnati College of Medicine, said in an American Academy of Pediatrics news release.
The researchers looked at PBDE levels in blood samples from 309 pregnant women and then performed intelligence and behavior tests on the women's children each year until they were 5.
They found that PBDE exposure in the womb was associated with hyperactivity at ages 2 to 5, and with lower intelligence at age 5. A tenfold increase in PBDE exposure during pregnancy was related to about a four-point IQ deficit in 5-year-old children.
While the study tied PBDE exposure during pregnancy to later hyperactivity and lower intelligence, it did not prove a cause-and-effect relationship.
The study was to be presented Monday at the Pediatric Academic Societies annual meeting in Washington, D.C.
PBDEs were mostly withdrawn from the U.S. market in 2004, but they are present in many consumer products bought several years ago and still widely used by Americans, according to the news release. In addition, PBDEs remain in human tissue for a long time and a pregnant woman can transfer them to her fetus.
"Because PBDEs exist in the home and office environment as they are contained in old furniture, carpet pads, foams and electronics, the study raises further concern about their toxicity in developing children," Chen concluded.
Research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.