Study Finds Striking Decline in Class of Flame Retardants Linked to Learning Problems in Children

A study in the September 25 issue of Environmental Science & Technology looks at a class of flame retardants in the blood of pregnant women and finds a striking decrease over a three year period. Ami R. Zota, ScD, MS, currently an assistant professor of environmental and occupational health at the George Washington University School of Public Health and Health Services (SPHHS), found a 65 percent drop in the average blood levels of polybrominated diphenyl ethers (PBDEs) found in pregnant women during the study.

PBDEs, which are used as flame retardants when embedded in furniture and other common products, are also linked to learning difficulties and health problems in children. Early development is an especially vulnerable time for the harmful effects of these chemicals, which can circulate in the blood of a pregnant woman and thus expose the developing fetus to these chemicals. Such exposure in the womb can later lead to IQ deficits, attention difficulties and other problems. Zota, who conducted the study while at the University of California, San Francisco, found that blood concentrations of these pollutants declined substantially during the study, probably because of California’s 2003 ban on these problematic chemicals.

The study was conducted only in pregnant women seeking medical care in San Francisco but Zota believes that the findings might apply to women across the country, noting that a national decision to phase out the use of these flame retardants in 2004 might also result in similar benefits.

Zota believes this study suggests that public policies aimed at restricting such chemicals really do work and can lead to a sharp decline in exposure to potentially toxic chemicals at the individual level (or in everyday lives). “That’s the good news,” Zota says. “At the same time, PBDEs persist in the environment for years.” Humans ingest small amounts of these chemicals in food, household dust and from other sources. This study, along with other evidence, suggests that the PBDE exposure in humans might decline rapidly after a ban and then hit a plateau, lingering in the environment for decades.

The findings add to evidence suggesting that a review of the Toxic Substances Control Act is needed, Zota says. The current law, which lawmakers are debating now, does not require manufacturers to provide the U.S. Environmental Protection Agency with safety information on chemicals—before they are routinely used in common household products. Tightening the law to require such health and safety information before a product is used in consumer products could prevent widespread exposure to chemicals that can persist in the environment and adversely impact human health, Zota says. 


About the George Washington University School of Public Health and Health Services:

Established in July 1997, the School of Public Health and Health Services brought together three longstanding university programs in the schools of medicine, business, and education and is now the only school of public health in the nation’s capital. Today, more than 1,100 students from nearly every U.S. state and more than 40 nations pursue undergraduate, graduate, and doctoral-level degrees in public health.  The school now offers an online Master of Public Health, MPH@GW, which allows students to pursue their degree from anywhere in the world.