This has raised serious concern about how these chemicals might affect our health. Studies in animals have found that PBDEs can hamper thyroid function, brain development, fertility, and liver function, and may cause cancer. More research is now being done in humans, and the results aren't reassuring—particularly when it comes to children.

In the latest study, researchers tested blood samples from the umbilical cords of 210 newborns. They then followed up with these children at ages 1, 2, 3, 4, and 6. The children with the highest levels of PBDEs in their cord blood scored lower on tests of mental and physical development at all five ages studied. The link was particularly strong at age 4, when verbal and full IQ scores were 5.5 to 8 points lower for those who had the highest PBDE exposure. Overall, the reductions in IQ scores were similar to those associated with low-level lead exposure, say the researchers.

This study was well designed and its findings should be fairly reliable, as the researchers took into account several other factors that might have affected the children's development, such as their mothers' age while pregnant and whether the children were born prematurely. However, the study didn't measure the children's PBDE exposure after their birth. It's possible that those exposed to higher levels in the womb continued to be exposed to higher levels. So children might have had poorer scores on these tests because of their contact with these chemicals after birth, rather than before. We need more research to explore this question as well as the possible effects of PBDEs in the womb.

What you need to know. This study provides more evidence about the probable harms of PBDE-based flame retardants. The good news is that some governments and manufacturers are taking note. Three large chemical companies recently agreed to phase out a common form of PBDEs called decabromodiphenyl ether (deca, for short). And deca has already been banned in some states. Several electronics manufacturers have also committed to phasing out PBDE flame retardants in their products, including Apple, LG Electronics, Sony-Ericsson, and Toshiba.

Unfortunately, these chemicals are already pervasive in our environment (not to mention our bodies). But you can take steps to lower your family's exposure. Here are some tips from the Environmental Working Group, a research and advocacy organization:

• Inspect foam items and replace those that have ripped covers or foam that is breaking down
• Use a vacuum cleaner with a HEPA filter. This can trap small particles and help remove contaminants from your home
• Keep children from touching or mouthing products that may contain PBDEs, such as cells phones and remotes, and always wash hands before eating
• Do your research before you buy new products. Check with manufacturers about what flame retardants they use. And, when possible, consider buying products made of naturally flame-resistant materials, such as wool, leather, and cotton.

—Sophie Ramsey, patient editor, BMJ Group

ConsumerReportsHealth.org has partnered with The BMJ Group to monitor the latest medical research and assess the evidence to help you decide which news you should use.