Sept. 4, 2008 -- Young children have three times the blood levels of fire-retardant chemicals as their mothers, according to a new study by the Environmental Working Group. The chemicals are routinely used in common household items such as furniture, mattresses, and electronics.
The gap between mothers and their children was a surprise finding. Because of typically similar diet and exposures in the same household, "we would have expected similar levels," says Anila Jacob, MD, MPH, a senior scientist at EWG. "What we found was, kids on average had three times the levels of toxic retardants polluting their blood compared to their moms."
The chemicals are hormone-disrupting and potentially hazardous, especially to young brain development, Jacob and her colleagues say. But a spokesman for the flame retardant industry countered that the levels of chemicals, known as PBDEs or polybrominated diphenyl ethers, found in the study are quite low, in the parts per billion range.
The EWG scientists tested the blood of 20 U.S. children ages 1 to 4 and their mothers, and evaluated the samples for PBDEs. In 19 of 20 pairs, Jacob tells WebMD, the children had a higher concentration than the mothers.
Two types of PBDEs, Penta and Octa, are no longer made in the U.S., Jacob says, but are still present in older items in households. The researchers found that another PBDE, known as Deca, showed up in 65% of the children tested and 45% of the adults.
They found total PBDE concentration in the children's blood averaged 62 parts per billion and ranged from 24 to 114 ppb. The concentration in the mothers' blood averaged 25 ppb and ranged from 10 to 74 ppb.
There is no established standard for safe blood levels, according to Jacob and Sonya Lunder, MPH, a senior analyst at EWG and a co-author of the report. "These findings raise concern about the effect of PBDEs on children's brain development," Lunder says. "These levels are uncomfortably close to doses found harmful in laboratory animals.''
Although there are no human studies, Jacob and Lunder point to studies conducted by the Environmental Protection Agency (EPA) and others finding that PBDEs can be especially toxic to the developing brains of animals, with even a single dose of PBDEs causing ill effects.
In laboratory tests on mice, researchers have found that a dose of PBDEs given on a single day when the brain is growing rapidly can cause hyperactivity and other changes to behavior, the EWG researchers note.
In another study, done in lab rats, Deca was linked to cancers, according to a report from the National Toxicology Program.
The new report, the authors say, is the first to show that U.S. children have much higher levels of PBDEs in their blood than their parents. It comes on the heels of a study from Australia, published in late August in the journal Environmental Science and Technology, in which researchers tested the blood of more than 8,000 residents and also found that the children had higher levels of PBDEs than the parents.
Fire Retardant Study: Industry Response
"The levels of PBDEs found are quite low," says John Kyte, a spokesman for The Bromine Science and Environmental Forum, an industry group based in Washington, D.C. "Even the highest numbers of PBDEs found are relatively low, in the parts per billion range."
Levels of Deca, the only PBDE still in use in the U.S. for new products, was especially low, he says. Deca "has been found to be safe for continued use," Kyle says.
"Flame retardants save actual human lives," with no evidence of illness or harm reported, Kyte says.
Fire Retardants: EPA Weighs In
The study results -- and the fact that a level of 114 parts per billion was the highest reported in children -- are "of concern," says Linda Birnbaum, PhD, a senior toxicologist with the EPA, who reviewed the study for WebMD. "What I see is another piece of evidence that supports the fact that levels of these chemicals in children appear to be higher than the levels in their parents," she says. "I think this study raises a red flag."
The EPA has set a "reference dose" for Deca, she says, which states that a daily oral dose of 7 micrograms per kilogram of body weight is believed to be without appreciable effects. But translating that to "safe" blood levels is not easy, she says, because the oral dose is different than what is stored in the body.
The EPA is studying the issue and working to better understand potential health hazards of Deca. The agency will soon start talking to U.S. makers of Deca, for instance, about the EPA's Voluntary Children's Chemical Evaluation Program, which the agency says will ensure that necessary testing of products is conducted to gain more knowledge about exposure for children and adults.
Fire Retardant Study: Another Opinion
The study suggests that exposure to the PBDEs is not good, especially during early development, says Irva Hertz-Picciotto, PhD, MPH, professor of health sciences and deputy director of the Center for Children's Environmental Health at the University of California, Davis.
The study, she tells WebMD, "does seem to establish that children are absorbing more than their mothers, even though they live in the same household environment, which has strong implications for their health and development."
There aren't studies in humans of the effects of PBDEs, says Hertz-Picciotto, who has studied PCB exposures in children. "Nevertheless, because these compounds appear to have similar properties to other, better studied ones, and because possible interactions among multiple chemical exposures could be especially detrimental, reducing exposures in your home could help protect our children."
Fire Retardants: What Can Parents Do?
Parents concerned about PBDE exposure can take a number of steps, Jacob says.
"Keep the house as dust free as possible," she says. It's believed the chemicals gather in house dust. Children's blood levels may be higher than their parents' level because they tend to play on the floor, she says.
"Use a HEPA filter when you vacuum," she suggests. Have children wash their hands carefully before eating, she says.
Be aware of which products may contain PBDEs, such as TVs, stereos, upholstered furniture, and mattresses and, to a lesser extent, alarm clocks, phones, and device chargers, the authors say.
When shopping for new products that may include PBDE, you can search out manufacturers who are shifting away from Deca, already restricted in Europe, Jacob says. Among manufacturers that have publicly committed to phasing out all brominated fire retardants include Acer, Apple, Eizo Nanao, LG Electronics, Lenovo, Matsushita, Microsoft, Nokia, Philips, Samsung, Sharp, Sony-Ericsson, and Toshiba.
Two states, Maine and Washington, have placed restrictions on Deca use and 10 other states have proposed such bans.