Prenatal exposure to some flame retardants that have been widely-used in consumer products is associated with attention problems in children ages three through seven, according to a new study by researchers at the Columbia Center for Children's Environmental Health, within Columbia's Mailman School of Public Health. The researchers are the first to show the effects of prenatal exposure to polybrominated diphenyl ethers (PBDEs) on children's development, during both the preschool and school age periods. Results appear in the journal of Neurotoxicology and Teratology.
PBDEs are found in textiles, plastics, wiring, and furniture containing polyurethane foam to reduce flammability. Since PBDEs are not chemically bound to these materials, they migrate into the environment over time. Humans are commonly exposed to the chemicals through accidental ingestion of house dust and by eating meat, dairy, and fatty fish with accumulated PBDEs. While PBDEs were phased out in 2004, they remain ubiquitous in the environment.
Researchers followed 210 mother-child pairs, a subset of the Center's World Trade Center study, from birth through early childhood. This cohort was established following the September 11, 2001 attack and designed to examine the effects of exposure to dust, smoke, and fumes on child development. Beginning at age 3, researchers assessed child behavior using a standardized rating scale, repeating the test ever year through age 7. Cord blood samples were analyzed for PBDEs to assess prenatal exposure to the chemicals.
At ages 3, 4, and 7 years, children with the highest exposure to certain PBDEs had approximately twice the number of maternally-reported attention problems compared to the other children in the study.
Investigators controlled for factors that have been previously associated with PBDE exposure levels or neurodevelopment in other studies including child age at testing, ethnicity, mother's IQ, child's sex, maternal age, marital status, prenatal exposure to environmental tobacco smoke, and maternal demoralization.
Results support previous peer-reviewed epidemiological studies reporting associations between prenatal PBDE exposure and symptoms of inattention, hyperactivity, and impulsivity among children.
"These findings reinforce the decision to phase-out the use of PBDEs in consumer products and support the need to develop programs for safely disposing of products containing PBDEs that are still in use," says senior author Julie Herbstman, assistant professor of Environmental Health Sciences.
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Whitney Cowell, a PhD candidate at the Mailman School, is the lead investigator on this work. Additional co-authors include Sally A. Lederman from Columbia's Institute of Human Nutrition; Andreas Sjödin, Richard Jones, and Richard Wang from the U.S. Centers for Disease Control and Prevention; and Shuang Wang, Frederica P. Perera, and Virginia A. Rauh from Columbia's Mailman School of Public Health.
Support for the study was provided by the National Institute of Environmental Health Sciences (grants ES09089, 5P01 ES09600, 5R01 ES08977, T32ES007322); U.S. Environmental Protection Agency (grant R827027); the September 11th Fund of the New York Community Trust and 9/11 Neediest Fund; the John and Wendy Neu Family Foundation; and the National Philanthropic Trust.
About Columbia University's Mailman School of Public Health
Founded in 1922, Columbia University's Mailman School of Public Health pursues an agenda of research, education, and service to address the critical and complex public health issues affecting New Yorkers, the nation and the world. The Mailman School is the third largest recipient of NIH grants among schools of public health. Its over 450 multi-disciplinary faculty members work in more than 100 countries around the world, addressing such issues as preventing infectious and chronic diseases, environmental health, maternal and child health, health policy, climate change & health, and public health preparedness. It is a leader in public health education with over 1,300 graduate students from more than 40 nations pursuing a variety of master's and doctoral degree programs. The Mailman School is also home to numerous world-renowned research centers including ICAP (formerly the International Center for AIDS Care and Treatment Programs) and the Center for Infection and Immunity. For more information, please visit http://www.mailman.columbia.edu.
Journal
Neurotoxicology and Teratology