THURSDAY, Nov. 15, 2012 (HealthDay News) -- Fetal or infant exposures to flame retardant chemicals that lurk in furniture, carpets and other household items could adversely affect a child's development, a new study suggests.
Exposure to the chemicals, known as polybrominated diphenyl ethers (PBDEs), was associated with a higher risk for physical and mental impairment when children reach school age.
"We observed associations of in utero and/or childhood exposure to these flame retardants and fine motor coordination, attention and IQ in school-age children," said study lead author Brenda Eskenazi, a professor of maternal and child health and epidemiology, and director of the Center for Environmental Research and Children's Health at the University of California, Berkeley.
PBDEs have long been recognized as potentially harmful "endocrine disrupters," which can be inhaled or ingested (via dust) and take up residence in fat cells. Eskenazi's team said the new study is the largest investigation of PBDE's impact on neurodevelopment to date.
According to background information supplied by the authors, PBDEs were first added to furniture, carpets, electronic goods and other consumer items in the 1970s in an effort to make products more flame-resistant. As their potential effects on health became better understood, however, many states moved to ban the chemicals. Nevertheless, PBDEs still can be found in many items manufactured before 2004, and exposures over the past few decades mean that 97 percent of U.S. residents carry blood levels of the chemicals.
To explore the potential impact of PBDE exposure among children, between 1999 and 2000 the authors collected blood samples from nearly 280 women over the age of 18, either while they were pregnant or at the time of their child's birth. Samples were also subsequently collected from 272 of the women's offspring when the children all turned 7 years of age.
The vast majority of parents and children were Mexican-American residents of Monterey County, Calif., who were participants in the ongoing Center for the Health Assessment of Mothers and Children of Salinas study.
Eskenazi said that her team focused on this group for practical reasons of access, and out of a particular interest in exploring the current PBDE situation in California. PBDE use in that state was particularly high, starting in the 1970s.
The blood samples were analyzed by the U.S. Centers for Disease Control and Prevention. At the same time, the children (ages 5 to 7) underwent rigorous mental capacity tests (covering verbal and reasoning skills, attention, behavior and memory) as well as coordination assessments. The mothers also reported their observations regarding their child's behavior.
Eskenazi's team found that although the mothers they tested had relatively low levels of PBDEs in their blood (compared with the general U.S. population), their offspring nonetheless had high levels. This suggests that the children have continued to absorb PBDEs after birth as a result of environmental exposures inside their homes.
"These chemicals stay in the body and in the environment for a long time," Eskenazi noted.
Children with higher blood levels of PBDEs tended to have deficits in attention, IQ and fine motor skills compared to kids without such levels, the team reported. While the study noted an association between higher PBDE exposures and childhood neurodevelopment, it could not prove cause-and-effect relationship.
According to the study authors, however, the findings do suggest that an item as innocuous as an old couch sold in California -- one that would have been fully code-compliant as recently as 10 years back -- would likely be embedded with PBDE and might pose a continuing risk to children.
The findings are published online Nov. 15 in Environmental Health Perspectives.
Prior studies involving the same group of mothers and children have found PBDE exposure during pregnancy to be tied to lower birth weight and thyroid problems, the authors noted.
Eskenazi stressed that while the PBDE levels found among the children in the study were higher than is generally found among the U.S. population, it is similar to other children living in California.
So, what should parents do to lower the risk? Eskenazi and her colleagues advise taking steps such as quickly sealing up any furniture/upholstery tears, and being vigilant about mopping and vacuuming to keep dust levels down. Routine hand-washing is also recommended.
Dr. Maida Galvez, an associate professor in the department of preventive medicine and pediatrics at the Mount Sinai School of Medicine in New York City, agreed with those precautionary measures.
And when families shop for furniture, she also suggested "choosing what are known to be safer alternatives, such as products filled with cotton, wool or polyester rather than chemical-treated foam. Families can also look for products that are flame-retardant free."
Find out more about PBDEs at the U.S. Centers for Disease Control and Prevention.