Prenatal exposure to a certain type of flame retardant that has commonly been used in consumer products is now being linked to attention problems in young children, 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 study is 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 years.
Although PBDEs were phased out in 2004, they still remain abundant in the environment. PBDEs can be found in textiles, plastics, wiring, and furniture that contain polyurethane foam added to reduce flammability.
Since PBDEs are not chemically bound to these materials, they tend to escape and 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.
For the study, researchers tracked 210 mother-child pairs, who were enrolled in 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.
Cord blood samples were analyzed for PBDEs to assess prenatal exposure to the chemicals. Then beginning at age three, researchers evaluated child behavior using a standardized rating scale, repeating the test every year through age seven.
The findings revealed that, at ages three, four, and seven years, children who had received the highest prenatal exposure to certain PBDEs had approximately twice the number of maternally reported attention problems compared to the other children in the study.
The researchers controlled for factors that had been previously tied to PBDE exposure levels or neurodevelopment in other studies. These included the child’s age at testing, ethnicity, mother’s IQ, child’s sex, maternal age, marital status, prenatal exposure to environmental tobacco smoke, and maternal demoralization.
The results of the study reflect 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,” said senior author Dr. Julie Herbstman, assistant professor of Environmental Health Sciences.
The study is published in the journal of Neurotoxicology and Teratology.