WEDNESDAY, April 20, 2011 (HealthDay News) -- Levels of flame-retardant chemicals are seven times higher in Mexican-American children living in California than in children in Mexico, a new study reports.
The researchers also found that levels of flame retardants -- polybrominated diphenyl ethers, or PBDEs -- in Mexican-American children in California were higher than those found in almost all other groups of children ever studied.
"Only Nicaraguan children who lived and worked on hazardous waste sites had higher reported levels of PBDEs in their bodies than the California children," study leader Brenda Eskenazi of the Center for Environmental Research and Children's Health at the University of California, Berkeley, said in a news release.
The findings appear online April 15 ahead of print in the journal Environmental Health Perspectives.
The researchers suggest that house dust was the major source of the kids' exposure to PBDEs.
PBDEs are used in a wide range of products, including the foam padding in upholstered furniture, carpet pads, child car seats and crib mattresses.
"These products tend to have long lifespans, and the flame retardants are not chemically bound to the materials they're used with," said study co-author Asa Bradman, also of the Center for Environmental Research and Children's Health. "As polyurethane foam and other materials containing the flame retardants age and degrade, they can release PBDEs into people's homes in the form of dust. And scientists know that when you have persistent pollutants in dust, they get into children."
And California's high anti-flammability standards for products may have inadvertently led to homes in the state having the highest levels of PDBEs in the United States, according to the researchers.
Prior research suggests exposure to high levels of PBDE's may impact fertility and thyroid hormone levels, according to the study.
For this study, researchers compared blood samples from 264 Mexican-American 7-year-olds in California and 283 children in Mexico, aged 5. The samples were analyzed for PBDEs and the pesticide DDT.
Levels of DDT and its breakdown product DDE were lower in the Mexican-American children in California than those in Mexico.
DDT has been banned in the United States since 1972.
The U.S. Agency for Toxic Substances and Disease Registry has more about PBDEs.